Patent Application
20170182207
The present invention related generally to a biocompatible device and methods of fabricating and using the device.
Fibrotic tissue adhesion and scar formation around medical devices (including but not limited to suture, stents, and mesh) are major complaints in current medical practices. However, current available medical devices do not effectively prevent fibrogenesis and scarring.
Fibromodulin (FMOD) is a member of a family of small interstitial proteoglycans that also includes decorin, biglycan and lumican. The proteoglycans bind to other matrix-molecules and thereby help to stabilize the matrix. (Buckwalter et al., Instr. Course Lect 477-86 (1998); Iozzo et al., Biology of Excellullar Matrix 197-231 (2011)). Proteoglycan protein cores are structurally related and consist of a central region of leucine-rich repeats flanked by disulfide-bonded terminal domains. Fibromodulin has up to 4 keratin sulfate chains within its leucine rich domain. It has a wide tissue distribution and is most abundant in articular cartilage, tendon and ligament. It has been suggested that fibromodulin participates in the assembly of the extracellular matrix due to its ability to interact with type I and type II collagen fibrils and to inhibit fribrillogenesis in vitro. In addition SLRP have matricellular functions to influence the function of cells and determine cell fate by modulating the matrix, or binding the cell surface receptors, or indirectly through modulation of growth factors (Iozzo et al., Biology of Extracellular Matrix 197-231 (2011), Zheng et al. Biomaterials 5821-31 (2012)).
The embodiments described below address the above described problems.
In one aspect of the present invention, it is provided a biocompatible device comprising a body structure and a wound-healing-enhancing agent in a wound-healing-enhancing effective amount, wherein the wound-healing-enhancing agent is embedded within the body structure or coated on the body structure.
In some embodiments of the invention device, optionally in combination with any of the various embodiments disclosed herein, the biocompatible device further comprises a carrier, wherein the wound-healing-enhancing agent is included in the carrier.
In some embodiments of the invention device, optionally in combination with any of the various embodiments disclosed herein, the biocompatible device further comprises a carrier, wherein the carrier comprises a gene construct encoding the wound-healing-enhancing agent.
In some embodiments of the invention device, optionally in combination with any of the various embodiments disclosed herein, the carrier is a coating comprising a polymeric material.
In some embodiments of the invention device, optionally in combination with any of the various embodiments disclosed herein, the polymeric material forms a top layer on top of the layer comprising a wound-healing-enhancing effective amount of the wound-healing-enhancing agent.
In some embodiments of the invention device, optionally in combination with any of the various embodiments disclosed herein, the carrier is a matrix material being admixed with or encapsulating the wound-healing-enhancing agent.
In some embodiments of the invention device, optionally in combination with any of the various embodiments disclosed herein, the carrier comprises microparticles and/or nanoparticles, wherein the wound-healing-enhancing agent is encapsulated within the microparticles and/or nanoparticles.
In some embodiments of the invention device, optionally in combination with any of the various embodiments disclosed herein, the wound-healing-enhancing agent is fibromodulin (FMOD), a FMOD polypeptide, a FMOD peptide, or a variant or analog or derivative thereof.
In some embodiments of the invention device, optionally in combination with any of the various embodiments disclosed herein, the biocompatible device is a medical implant or cosmetic implant.
In some embodiments of the invention device, optionally in combination with any of the various embodiments disclosed herein, the biocompatible device is a surgical suture.
In another aspect of the present invention, it is provided a method of fabricating a biocompatible device, which method comprising:
providing a wound-healing-enhancing agent in a wound-healing-enhancing effective amount; and
forming the biocompatible device comprising a body structure of the biocompatible device and the wound-healing-enhancing agent,
wherein the wound-healing-enhancing agent is embedded within the body structure or coated on the body structure.
In some embodiments of the invention method, optionally in combination with any of the various embodiments disclosed herein, the device further comprises a carrier, wherein the wound-healing-enhancing agent is included in the carrier.
In some embodiments of the invention method, optionally in combination with any of the various embodiments disclosed herein, the device further comprises a carrier, wherein the carrier comprises a gene construct encoding the wound-healing-enhancing agent.
In some embodiments of the invention method, optionally in combination with any of the various embodiments disclosed herein, the carrier is a coating comprising a polymeric material.
In some embodiments of the invention method, optionally in combination with any of the various embodiments disclosed herein, the polymeric material forms a top layer on top of the layer comprising a wound-healing-enhancing effective amount of the wound-healing-enhancing agent.
In some embodiments of the invention method, optionally in combination with any of the various embodiments disclosed herein, the carrier is a matrix material being admixed with or encapsulating the wound-healing-enhancing agent.
In some embodiments of the invention method, optionally in combination with any of the various embodiments disclosed herein, the carrier comprises microparticles and/or nanoparticles, wherein the wound-healing-enhancing agent is encapsulated within the microparticles and/or nanoparticles.
In some embodiments of the invention method, optionally in combination with any of the various embodiments disclosed herein, the wound-healing-enhancing agent is fibromodulin (FMOD), a FMOD polypeptide, a FMOD peptide, or a variant or analog or derivative thereof.
In some embodiments of the invention method, optionally in combination with any of the various embodiments disclosed herein, the device is a medical implant or cosmetic implant.
In some embodiments of the invention method, optionally in combination with any of the various embodiments disclosed herein, the device is a surgical suture.
In a further aspect of the present invention, it is provided a method of treating or ameliorating a disorder, comprising implanting in a subject a biocompatible device according to any of the various embodiments provided herein.
In some embodiments of the invention method, optionally in combination with any of the various embodiments disclosed herein, the device is a medical implant or cosmetic implant.
In some embodiments of the invention method, optionally in combination with any of the various embodiments disclosed herein, the device is a surgical suture.
We have demonstrated that fibromodulin (FMOD) protein and its derived peptide can optimize wound healing by accelerating cell migration and contraction, minimizing fibrotic extracellular matrix (ECM) production and deposition, while increasing tensile strength. This procedure for protein/peptide-coating on various medical devices is different from our previous invention, which uses FMOD protein or its derived peptide directly as a wound-healing-enhancing therapeutic medicine.
As used herein, the term “fibromodulin polypeptide” refers to a polypeptide of SEQ ID NO. 1 (Genbank Accession No. NM 002023) or to a conservative substitution variant or fragment thereof that retains fibromodulin activity as that term is defined herein. It should be understood that the carbohydrate moieties of fibromodulin can be involved in fibromodulin pro-angiogenic activity, including, e.g., N-linked keratin sulfate chains. The leucine-rich repeats in the C-terminal domain of the fibromodulin polypeptide have been implicated in the binding of fibromodulin to type I collagen and can play a role in fibromodulin pro-angiogenic activity. See e.g., Kalamaj ski and Oldberg, (2007) J Biol Chem 282:26740-26745, which highlights the role of leucine-rich repeats in type I collagen binding. By “retaining fibromodulin activity” is meant that a polypeptide retains at least 50% of the fibromodulin activity of a polypeptide of SEQ ID NO. 1. Also encompassed by the term “fibromodulin polypeptide” are mammalian homologs of human fibromodulin and conservative substitution variants or fragments thereof that retain fibromodulin activity. In one aspect, such homologs or conservative variants thereof stimulate human endothelial cell growth and/or migration as measured, for example, as described herein. In some embodiments, the term fibromodulin polypeptide also includes the various peptides disclosed in U.S. patent application publication No. 20120171253, the teaching of which is incorporated herein in its entirety by reference.
The term “variant” as used herein refers to a polypeptide or nucleic acid that is “substantially similar” to a wild-type fibromodulin polypeptide or polynucleic acid. A molecule is said to be “substantially similar” to another molecule if both molecules have substantially similar structures (i.e., they are at least 50% similar in amino acid sequence as determined by BLASTp alignment set at default parameters) and are substantially similar in at least one relevant function (e.g., effect on cell migration). A variant differs from the naturally occurring polypeptide or nucleic acid by one or more amino acid or nucleic acid deletions, additions, substitutions or side-chain modifications, yet retains one or more specific functions or biological activities of the naturally occurring molecule amino acid substitutions include alterations in which an amino acid is replaced with a different naturally-occurring or a non-conventional amino acid residue. Some substitutions can be classified as “conservative,” in which case an amino acid residue contained in a polypeptide is replaced with another naturally occurring amino acid of similar character either in relation to polarity, side chain functionality or size. Substitutions encompassed by variants as described herein can also be “non-conservative,” in which an amino acid residue which is present in a peptide is substituted with an amino acid having different properties (e.g., substituting a charged or hydrophobic amino acid with an uncharged or hydrophilic amino acid), or alternatively, in which a naturally-occurring amino acid is substituted with a non-conventional amino acid. Also encompassed within the term “variant,” when used with reference to a polynucleotide or polypeptide, are variations in primary, secondary, or tertiary structure, as compared to a reference polynucleotide or polypeptide, respectively (e.g., as compared to a wild-type polynucleotide or polypeptide). Polynucleotide changes can result in amino acid substitutions, additions, deletions, fusions and truncations in the polypeptide encoded by the reference sequence. Variants can also include insertions, deletions or substitutions of amino acids, including insertions and substitutions of amino acids and other molecules) that do not normally occur in the peptide sequence that is the basis of the variant, including but not limited to insertion of ornithine which does not normally occur in human proteins.
The term “derivative” as used herein refers to peptides which have been chemically modified, for example by ubiquitination, labeling, PEGylation (derivatization with poly-ethylene glycol), glycosylation, protein fusion, or addition of other molecules. A molecule is also a “derivative” of another molecule when it contains additional chemical moieties not normally a part of the molecule. Such moieties can improve the molecule's solubility, absorption, biological half-life, etc. The moieties can alternatively decrease the toxicity of the molecule, or eliminate or tenuate an undesirable side effect of the molecule, etc. Moieties capable of mediating such effects are disclosed in Remington's Pharmaceutical Sciences, 18th edition, A. R. Gennaro, Ed., MackPubl., Easton, Pa. (1990).
The term “functional” when used in conjunction with “derivative” or “variant” refers to polypeptides which possess a biological activity that is substantially similar to a biological activity of the entity or molecule of which it is a derivative or variant. By “substantially similar” in this context is meant that at least 50% of the relevant or desired biological activity of a corresponding wild-type peptide is retained. In the instance of promotion of angiogenesis, for example, an activity retained would be promotion of endothelial cell migration; preferably the variant retains at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 100% or even higher (i.e., the variant or derivative has greater activity than the wild-type), e.g., at least 110%, at least 120%, or more compared to a measurable activity (i.e., promotion or inhibition of endothelial cell migration) of the wild-type polypeptide.
The term “wound-healing-enhancing agent” refers to an agent that is effective to produce a statistically significant, measurable improvement in wound healing of an injured tissue, e.g., reduction in fibrotic formation, e.g., reduction of scar formation, as compared with wound healing without using the wound-healing-enhancing agent of invention. As such, the term “wound-healing-enhancing effective amount” is an amount of an agent that is sufficient to produce a statistically significant, measurable improvement in wound healing of an injured tissue, e.g., reduction in fibrotic formation, e.g., reduction of scar formation, as compared with wound healing without using the wound-healing-enhancing agent of invention. As used herein, the term “wound-healing-enhancing effective amount” explicitly excludes an amount for forming reduced scarring in skin healing or cornea.
As used herein, the term “wound” includes an acute wounds as well as chronic wounds. Wound-healing includes healing of wounds in any tissue, e.g., healing fascia, tendon, etc. A mode of action of FMOD is to accelerate cell migration, cell contraction, and to minimize ECM deposition, while increasing tensile strength of the repair. The present invention has broad applications to everything aspect of wound repair including anti-fibrosis.
As used herein the term “comprising” or “comprises” is used in reference to compositions, methods, and respective component(s) thereof, that are essential to the invention, yet open to the inclusion of unspecified elements, whether essential or not.
As used herein the term “consisting essentially” of refers to those elements required for a given embodiment. The term permits the presence of elements that do not materially affect the basic and novel or functional characteristic(s) of that embodiment of the invention.
The term “consisting” of refers to compositions, methods, and respective components thereof as described herein, which are exclusive of any element not recited in that description of the embodiment.
As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. Thus for example, references to “the method” includes one or more methods, and/or steps of the type described herein and/or which will become apparent to those persons skilled in the art upon reading this disclosure and so forth.
The term “carrier” includes any biocompatible material, which can be a metallic material or non-metallic materials. Examples of metallic materials includes titanium, zirconium, silver, gold, platinum, stainless steel, Cr—Co alloy, a Ti—Ni alloy, aluminum, magnesium, or any alloy formed thereof. Non-metallic materials include cement, ceramics, bioglass, natural polymer, synthetic polymer, for example. Some examples of polymer materials are described further below.
As used herein, the term “a wound-healing agent” refers to an agent that is commonly used in wound-healing.
As used herein, the term “body structure” refers to the mechanical structure of a device of invention provided herein.
In one aspect of the present invention, it is provided a biocompatible device comprising a body structure and a wound-healing-enhancing agent in a wound-healing-enhancing effective amount, wherein the wound-healing-enhancing agent is embedded within the body structure or coated on the body structure.
In some embodiments of the invention device, optionally in combination with any of the various embodiments disclosed herein, the biocompatible device further comprises a carrier, wherein the wound-healing-enhancing agent is included in the carrier.
In some embodiments of the invention device, optionally in combination with any of the various embodiments disclosed herein, the biocompatible device further comprises a carrier, wherein the carrier comprises a gene construct encoding the wound-healing-enhancing agent.
In some embodiments of the invention device, optionally in combination with any of the various embodiments disclosed herein, the carrier is a coating comprising a polymeric material.
In some embodiments of the invention device, optionally in combination with any of the various embodiments disclosed herein, the polymeric material forms a top layer on top of the layer comprising a wound-healing-enhancing effective amount of the wound-healing-enhancing agent.
In some embodiments of the invention device, optionally in combination with any of the various embodiments disclosed herein, the carrier is a matrix material being admixed with or encapsulating the wound-healing-enhancing agent.
In some embodiments of the invention device, optionally in combination with any of the various embodiments disclosed herein, the carrier comprises microparticles and/or nanoparticles, wherein the wound-healing-enhancing agent is encapsulated within the microparticles and/or nanoparticles.
In some embodiments of the invention device, optionally in combination with any of the various embodiments disclosed herein, the wound-healing-enhancing agent is fibromodulin (FMOD), a FMOD polypeptide, a FMOD peptide, or a variant or analog or derivative thereof.
In some embodiments of the invention device, optionally in combination with any of the various embodiments disclosed herein, the biocompatible device is a medical implant or cosmetic implant.
In some embodiments of the invention device, optionally in combination with any of the various embodiments disclosed herein, the biocompatible device is a surgical suture.
In connection with the above various carrier, matrix, or coating configurations, the top layer or the matrix material can be used along or in combination to provide controlled release of the wound-healing-enhancing agent from the biocompatible device. In the case where the coated device includes no polymeric material, the release of the wound-healing-enhancing agent from the biocompatible device is burst release.
In some embodiments of the invention device, optionally in combination with any or all of the various embodiments disclosed herein, the wound-healing-enhancing agent is fibromodulin (FMOD), a FMOD polypeptide, a FMOD peptide, or a variant or analog or derivative thereof.
The biocompatible device can be any device for use where a disorder can be treated or alleviated by implanting the device in a subject (e.g., a human patient). Examples of such biocompatible devices include, but not limited to, implanted medical devices (e.g, mesh, anti-adhesion devices, nerve or vascular conduits, breast implants, tissue expanders, pacemakers, defibrillators, neurostimulators, or other electrical devices), percutaneously delivered devices (e.g., stents), wound closure devices (e.g., sutures, staples), wound management coverings (tapes, membranes for guided tissue regeneration) and tissue engineering scaffolds for which scar formation must be avoided (e.g. orbital wall reconstruction—bone formation must occur without scarring of the soft tissues) to avoid undesired surgery-induced fibrotic adhesion and scar formation or gliosis (scar in central nervous system) in all operated on tissues on organ systems (e.g., brain, heart, lungs, liver, intestine, blood vessels, nerves, muscle, tendon, eye, inner ear, sinus, etc.) using all available approaches (e.g., open surgery, endoscopic surgery, minimally invasive, percutaneous, etc.)
In some embodiments, the biocompatible device can be cosmetic implants. Such cosmetic implants include, e.g., a breast implant, pectoral implant, chin implant, or malar implant.
In some embodiments, the biocompatible device specifically excludes such devices disclosed in WO2004053101 A3 or WO2009135135 A3 in connection with skin wound healing or cornea wound healing.
Some other examples of the biocompatible devices are stents, such as protein-eluting biodegradable polymer stents on anastomotic wound healing after biliary reconstruction, or coronary stents, which are implanted in narrowed coronary arteries during surgery.
Fibromodulin (FMOD), also called SLRR2E, is a member of a family of small interstitial proteoglycans. The protein is 59 kDa with leucine-rich repeats flanked by disul-fide-bonded terminal domains, possessing up to 4 keratan sulfate chains (Takahashi, T., Cho, H. I., Kublin, C. L. & Cintron, C. (1993) J Histochem Cytochem 41:1447-57). Fibromodulin exhibits a wide tissue distribution with the highest concentration found in articular cartilage, tendon, and ligament. The subcellular location of fibromodulin is within the cytosolic proteins with a secretory sequence but no trans-membrane or extracellular domain.
While it is not wished to indicate that such activity is critical to the pro-angiogenic activity of fibromodulin, several activities of fibromodulin are worth noting here. A characteristic feature of this protein is its participation in the assembly of the extracellular matrix by virtue of its ability to interact with type I, type II and XII collagen fibrils to form collagen fibrils network (Hedbom, E. & Heinegard, D. (1993) J Biol Chem 268: 27307-12; Font, B., Eichenberger, D., Goldschmidt, D., Boutillon, M. M. & Hulmes, D. J. (1998) Eur J Biochem 254:580-7) and to inhibit fibrillogenesis in vitro (Antonsson, P., Heinegard, D. & Oldberg, A. (1991) J Biol Chem 266:16859-61; Hedlund, H., Mengarelli-Widholm, S., Heinegard, D., Reinholt, F. P. & Svensson, O. (1994) Matrix Biol 14:227-32; Ezura, Y., Chakravarti, S., Oldberg, A., Chervoneva, I. & Birk, D. E. (2000)J Cell Biol 151:779-88; Gori, F., Schipani, E. & Demay, M. B. (2001) J Cell Biochem 82:46-57; Ameye, L. et al. (2002) Faseb J16: 673-80; Ameye, L. & Young, M. F. (2002) Glycobiology 12:107R-16R; Chakravarti, S. (2002) Glycoconj J19:287-93) FMOD interaction with transforming growth factor (TGF)-β, a key profibrotic cytokine, is considered to enhance the retention of this growth factor within the extracellular matrix (ECM), thus regulating TGF-β local action (Burton-Wurster, N. et al. (2003) Osteoarthritis Cartilage 11:167-76; San Martin, S. et al. (2003) Reproduction 125:585-95; Fukushima, D., Butzow, R., Hildebrand, A. & Ruoslahti, E. (1993) J Biol Chem 268:22710-5; Hildebrand, A. et al. (1994) Biochem J302 (Pt 2):527-34). The protein is involved in a variety of adhesion processes of connective tissue, and with immunoglobulins activating both the classical and the alternative pathways of complement. Further studies revealed that fibromodulin binds directly to the globular heads of Clq, leading to activation of Cl. Fibromodulin also binds complement inhibitor factor H (Sjoberg, A. P. et al. (2007) J Biol Chem 282:10894-900; Sjoberg, A., Onnerfjord, P., Morgelin, M., Heinegard, D. & Blom, A. M. (2005) J Biol Chem 280:32301-8)
The fibromodulin gene has been found to be an overexpressed gene in B-cell chronic lymphocytic leukemia and chronic lymphocytic leukemia (CLL). It may serve as a potential tumor-associated antigen (TAA) in CLL (Mayr, C. et al. (2005) Blood 105:1566-73; Mayr, C. et al. (2005) Blood 106:3223-6). The amino acid sequences of human and bovine, rat and murine fibromodulin show an overall homology of 90%, allowing for close translation between human and murine experimental models (Antons son, P., Heinegard, D. & Oldberg, A. (1993) Biochim Biophys Acta 1174:204-6).
Essentially any agent that enhances fibromodulin activity, as that term is defined herein, can be used with the methods described herein. It is preferred, however, that an enhancer of fibromodulin activity is specific, or substantially specific, for fibromodulin activity promotion. Further, it is noted that fibromodulin activity can be enhanced by agents that specifically promotes the expression of the fibromodulin proteoglycan.
It will be understood by one of skill in the art that the method and composition provided herein can be used to impart enhancing wound healing and/or any other advantageous property to any device that is used as a medical implant. In some embodiments, devices provided herein include medical implants, scaffolds and/or medical instruments. Exemplary medical implants include but are not limited to sutures, stents, balloons, valves, pins, rods, screws, discs, and plates. Exemplary medical implants include but are not limited to an artificial replacement of a body part such as a hip, a joint, etc.
In some embodiments, the implant can be one of cosmetric implants, such as but not limited to breast implants, pectoral implants, chin implants, malar implants, et al.
In some embodiments, the devices include a biocompatible intervertebral device (e.g., a cervical fusion device).
In some embodiments, devices disclosed herein include those associated with dental surgeries, including but not limited to a disc, a bridge, a retainer clip, a screw, a housing, a bone graft, and/or a crown.
In some embodiments, devices disclosed herein include those associated with orthopedic surgeries, including, for example, intramedullary rods, temporary and permanent pins and implants, bone plates, bone screws and pins, and combinations thereof.
Additional information on biocompatible medical devices and osteoinductive materials can be found, for example, in United States Patent Publication No. 2009/0012620 by Youssef J., et al. and entitled “Biocompatible Cervical Fusion Device;” U.S. Pat. No. 5,348,026 to Davidson and entitled “Osteoinductive Bone Screw;” Barradas A. et al, 2011, “Osteoinductive Biomaterials: Current Knowledge of Properties, Experimental Models and Biological Mechanisms,” European Cells and Materials 21:407-429; U.S. Pat. No. 7,485,617 to Pohl J. et al. and entitled “Osteoinductive Materials,” United States Patent Publication No. 2011/0022180 by Melkent A., et al. and entitled “Implantable Medical Devices;” United States Patent Publication No. 2005/0010304 by Jamali, A. and entitled “Device and Method for Reconstruction of Osseous Skeletal Defects;” United States Patent Publication No. 2010/0036502 by Svrluga R. et al. and entitled “Medical Device for Bone Implant and Method for Producing Such Device;” U.S. Pat. No. 5,672,177 to E. Seldin and entitled “Implantable Bone Distraction Device;” and U.S. Pat. No. 4,611,597 to W. Kraus and entitled “Implantable Device for the Stimulation of Bone Growth;” each of which is hereby incorporated by reference in its entirety.
A fibromodulin polypeptide or a portion thereof functional to promote angiogenesis can be administered to an individual in need thereof. In one approach, a soluble fibromodulin polypeptide, produced, for example, in cultured cells bearing a recombinant fibromodulin expression vector can be administered to the individual. The fibromodulin polypeptide or portion thereof will generally be administered intravenously. This approach rapidly delivers the protein throughout the system and maximizes the chance that the protein is intact when delivered. Alternatively, other routes of therapeutic protein administration are contemplated, such as by inhalation. Technologies for the administration of agents, including protein agents, as aerosols are well known and continue to advance. Alternatively, the polypeptide agent can be formulated for topical delivery, including, for example, preparation in liposomes. Further contemplated are, for example, trans-dermal administration, and rectal or vaginal administration. Further options for the delivery of fibromodulin polypeptides as described herein are discussed in the section “Pharmaceutical Compositions” herein below.
Vectors for transduction of a fibromodulin-encoding sequence are well known in the art. While overexpression using a strong non-specific promoter, such as a CMV pro-moter, can be used, it can be helpful to include a tissue- or cell-type-specific promoter on the expression construct for example, the use of a skeletal muscle-specific promoter or other cell-type-specific promoter can be advantageous, depending upon what cell type is used as a host. Further, treatment can include the administration of viral vectors that drive the expression of fibromodulin polypeptides in infected host cells. Viral vectors are well known to those skilled in the art.
These vectors are readily adapted for use in the methods of the present invention. By the appropriate manipulation using recombinant DNA/molecular biology techniques to insert an operatively linked fibromodulin encoding nucleic acid segment into the selected expression/delivery vector, many equivalent vectors for the practice of the methods described herein can be generated. It will be appreciated by those of skill in the art that cloned genes readily can be manipulated to alter the amino acid sequence of a protein.
The cloned gene for fibromodulin can be manipulated by a variety of well-known techniques for in vitro mutagenesis, among others, to produce variants of the naturally occurring human protein, herein referred to as muteins or variants or mutants of fibromodulin, which may be used in accordance with the methods and compositions described herein. The variation in primary structure of muteins of fibromodulin useful in the invention, for instance, may include deletions, additions and substitutions. The substitutions may be conservative or non-conservative. The differences between the natural protein and the mutein generally conserve desired properties, mitigate or eliminate undesired properties and add desired or new properties. The fibromodulin polypeptide can also be a fusion polypeptide, fused, for example, to a polypeptide that targets the product to a desired location, or, for example, a tag that facilitates its purification, if so desired. Fusion to a polypeptide sequence that increases the stability of the fibromodulin polypeptide is also contemplated. For example, fusion to a serum protein, e.g., serum albumin, can increase the circulating half-life of a fibromodulin polypeptide. Tags and fusion partners can be designed to be cleavable, if so desired. Another modification specifically contemplated is attachment, e.g., covalent attachment, to a polymer. In one aspect, polymers such as polyethylene glycol (PEG) or methoxypolyethylene glycol (mPEG) can increase the in vivo half-life of proteins to which they are conjugated. Methods of PEGylation of polypeptide agents are well known to those skilled in the art, as are considerations of, for example, how large a PEG polymer to use. In another aspect, biodegradable or absorbable polymers can provide extended, often localized, release of polypeptide agents. Such synthetic bioabsorbable, biocompatible polymers, which may release proteins over several weeks or months can include, for example, poly-α-hydroxy acids (e.g. polylactides, polyglycolides and their copolymers), polyanhydrides, polyorthoesters, segmented block copolymers of polyethylene glycol and polybutylene terephtalate (Polyactive™), tyrosine derivative polymers or poly(ester-amides). Suitable bioabsorbable polymers to be used in manufacturing of drug delivery materials and implants are discussed e.g. in U.S. Pat. Nos. 4,968,317; 5,618,563, among others, and in “Biomedical Polymers” edited by S. W. Shalaby, Carl Hanser Verlag, Munich, Vienna, N.Y., 1994 and in many references cited in the above publications. The particular bioabsorbable polymer that should be selected will depend upon the particular patient that is being treated.
In some embodiments, the anti-fibrotic coating comprises a polymeric material. Exemplary polymeric material that can be used here include but are not limited to a biocompatible or bioabsorbable polymer that is one or more of poly(DL-lactide), poly(L-lactide), poly(
In some embodiments, the polymeric material comprises poly(
In some embodiments, polymers that are more flexible or that have a lower modulus that those mentioned above may also be used. Exemplary lower modulus bioabsorbable polymers include, polycaprolactone (PCL), poly(trimethylene carbonate) (PTMC), polydioxanone (PDO), poly(3-hydrobutyrate) (PHB), poly(4-hydroxybutyrate) (P4HB), poly(hydroxyalkanoate) (PHA), and poly(butylene succinate), and blends and copolymers thereof.
In exemplary embodiments, higher modulus polymers such as PLLA or PLLGA may be blended with lower modulus polymers or copolymers with PLLA or PLGA. The blended lower modulus polymers result in a blend that has a higher fracture toughness than the high modulus polymer. Exemplary low modulus copolymers include poly(L-lactide)-b-polycaprolactone (PLLA-b-PCL) or poly(L-lactide)-co-polycaprolactone (PLLA-co-PCL). The composition of a blend can include 1-5 wt % of low modulus polymer.
More exemplary polymers include but are not limited to at least partially alkylated polyethyleneimine (PEI); at least partially alkylated poly(lysine); at least partially alkylated polyornithine; at least partially alkylated poly(amido amine), at least partially alkylated homo- and co-polymers of vinylamine; at least partially alkylated acrylate containing aminogroups, copolymers of vinylamine containing aminogroups with hydrophobic monomers, copolymers of acrylate containing aminogroups with hydrophobic monomers, and amino containing natural and modified polysaccharides, polyacrylates, polymethacryates, polyureas, polyurethanes, polyolefins, polyvinylhalides, polyvinylidenehalides, polyvinylethers, polyvinylaromatics, polyvinylesters, polyacrylonitriles, alkyd resins, polysiloxanes and epoxy resins, and mixtures thereof. Additional examples of biocompatible biodegradable polymers include, without limitation, polycaprolactone, poly(
In some embodiments, polyethylene is used to construct at least a portion of the device. For example, polyethylene can be used in an orthopedic implant on a surface that is designed to contact another implant, as such in a joint or hip replacement. Polyethylene is very durable when it comes into contact with other materials. When a metal implant moves on a polyethylene surface, as it does in most joint replacements, the contact is very smooth and the amount of wear is minimal. Patients who are younger or more active may benefit from polyethylene with even more resistance to wear. This can be accomplished through a process called crosslinking, which creates stronger bonds between the elements that make up the polyethylene. The appropriate amount of crosslinking depends on the type of implant. For example, the surface of a hip implant may require a different degree of crosslinking than the surface of a knee implant.
Additional examples of polymeric materials can be found, for example, in U.S. Pat. No. 6,127,448 to Domb, entitled “Biocompatible Polymeric Coating Material;” US Pat. Pub. No. 2004/0148016 by Klein and Brazil, entitled “Biocompatible Medical Device Coatings;” US Pat. Pub. No. 2009/0169714 by Burghard et al, entitled “Biocompatible Coatings for Medical Devices;” U.S. Pat. No. 6,406,792 to Briquet et al, entitled “Biocompatible Coatings;” US Pat. Pub. No. 2008/0003256 by Martens et al, entitled “Biocompatible Coating of Medical Devices;” each of which is hereby incorporated by reference herein in its entirety.
In some embodiments, a portion of or the entire device is formed by one or more the aforementioned polymeric materials provided herein. In some embodiments, the polymeric material used to form the device further comprises an antimicrobial agent such that the antimicrobial agent is embedded as a part of the device itself. In some embodiments, a biomedical material such as titanium, silicone or apatite is used to modify the surface of the device such that the device is biocompatible and does not trigger adverse reactions in a patient (e.g., a recipient of an implant).
In some embodiments, a portion of or the entire device is made from a metal material. Exemplary metal materials include but are not limited to stainless steel, chromium, a cobalt-chromium alloy, tantalum, titanium, a titanium alloy and combinations thereof.
Stainless steel is a very strong alloy, and is most often used in implants that are intended to help repair fractures, such as bone plates, bone screws, pins, and rods. Stainless steel is made mostly of iron, with other metals such as chromium or molybdenum added to make it more resistant to corrosion. There are many different types of stainless steel. The stainless steels used in orthopedic implants are designed to resist the normal chemicals found in the human body. Cobalt-chromium alloys are also strong, hard, biocompatible, and corrosion resistant. These alloys are used in a variety of joint replacement implants, as well as some fracture repair implants, that require a long service life. While cobalt-chromium alloys contain mostly cobalt and chromium, they also include other metals, such as molybdenum, to increase their strength. Titanium alloys are considered to be biocompatible. They are the most flexible of all orthopedic alloys. They are also lighter weight than most other orthopedic alloys. Consisting mostly of titanium, they also contain varying degrees of other metals, such as aluminum and vanadium. Pure titanium may also be used in some implants where high strength is not required. It is used, for example, to make fiber metal, which is a layer of metal fibers bonded to the surface of an implant to allow the bone to grow into the implant, or cement to flow into the implant, for a better grip. Tantalum is a pure metal with excellent physical and biological characteristics. It is flexible, corrosion resistant, and biocompatible.
In another aspect of the present invention, it is provided a method of fabricating a biocompatible device, which method comprising:
providing a wound-healing-enhancing agent in a wound-healing-enhancing effective amount; and
forming the biocompatible device comprising a body structure of the biocompatible device and the wound-healing-enhancing agent,
wherein the wound-healing-enhancing agent is embedded within the body structure or coated on the body structure.
In some embodiments of the invention method, optionally in combination with any of the various embodiments disclosed herein, the device further comprises a carrier, wherein the wound-healing-enhancing agent is included in the carrier.
In some embodiments of the invention method, optionally in combination with any of the various embodiments disclosed herein, the device further comprises a carrier, wherein the carrier comprises a gene construct encoding the wound-healing-enhancing agent.
In some embodiments of the invention method, optionally in combination with any of the various embodiments disclosed herein, the carrier is a coating comprising a polymeric material.
In some embodiments of the invention method, optionally in combination with any of the various embodiments disclosed herein, the polymeric material forms a top layer on top of the layer comprising a wound-healing-enhancing effective amount of the wound-healing-enhancing agent.
In some embodiments of the invention method, optionally in combination with any of the various embodiments disclosed herein, the carrier is a matrix material being admixed with or encapsulating the wound-healing-enhancing agent.
In some embodiments of the invention method, optionally in combination with any of the various embodiments disclosed herein, the carrier comprises microparticles and/or nanoparticles, wherein the wound-healing-enhancing agent is encapsulated within the microparticles and/or nanoparticles.
In some embodiments of the invention method, optionally in combination with any of the various embodiments disclosed herein, the wound-healing-enhancing agent is fibromodulin (FMOD), a FMOD polypeptide, a FMOD peptide, or a variant or analog or derivative thereof.
In some embodiments of the invention method, optionally in combination with any of the various embodiments disclosed herein, the device is a medical implant or cosmetic implant.
In some embodiments of the invention method, optionally in combination with any of the various embodiments disclosed herein, the device is a surgical suture.
The coated biocompatible device can be fabricated by forming a coating comprising a wound-healing-enhancing effective amount of a wound-healing-enhancing agent. In some embodiments, the wound-healing-enhancing agent can be formed as a layer on the biocompatible device. In some embodiments, the wound-healing-enhancing agent is FMOD, FMOD polypeptide, FMOD peptide, or a variant or a derivative thereof such that the biocompatible device comprises a coating comprising a wound-healing-enhancing effective amount of FMOD, FMOD polypeptide, FMOD peptide, or a variant or a derivative thereof.
In some embodiments, the coating can further comprise a polymer material. The polymeric material can be a top layer formed on top of the layer of the wound-healing-enhancing agent. In some other embodiments, the polymeric material can be a matrix material admixed with or encapsulating the wound-healing-enhancing agent. The top layer or the matrix material can be used alone or in combination to provide controlled release of the wound-healing-enhancing agent from the biocompatible device. In the case where the coated device includes no polymeric material, the release of the wound-healing-enhancing agent from the biocompatible device is burst release.
In some embodiments, the coating can further comprise a polymer material matrix and encapsulated nanoparticles/microparticles. The polymeric material can be a top layer and as matrix encapsulating nanoparticles/mciroparticles containing the wound-healing-enhancing agent. In some other embodiments, the polymeric material can be a matrix material admixed with or encapsulating the nanoparticles/mciroparticles. The top layer or the matrix material can be used alone or in combination with particles to provide sustained release of the wound-healing-enhancing agent from the biocompatible device. In the case the nanoparticles/microparticles could be prepared by any material include but are not limited to natural polymers, synthetic polymers, inorganic chemicals, at least partially dextran, chitosan, collagen, silica, calcium phosphate, poly(D,L-lactide), poly(L-lactide), polyglycolide, poly(D,L-lactide-co-glycolide), poly(L-lactide-co-glycolide), polycaprolactone, poly(lactide-co-caprolactone), poly(glycolide-co-caprolactone), poly(dioxanone), poly(ortho esters), poly(anhydrides), poly(tyrosine carbonates) and derivatives thereof, Methods of coating a device are well documented in the art. Examples of such methods include dip coating or spray coating using a solution or suspension, which solution or suspension comprising the wound-healing-enhancing agent disclosed herein, the polymeric material disclosed herein, alone or in combination.
In a further aspect of the present invention, it is provided a method of treating or ameliorating a disorder, comprising implanting in a subject a biocompatible device according to any of the various embodiments provided herein.
In some embodiments of the invention method, optionally in combination with any of the various embodiments disclosed herein, the device is a medical implant or cosmetic implant.
In some embodiments of the invention method, optionally in combination with any of the various embodiments disclosed herein, the device is a surgical suture.
The wound-healing-enhancing biocompatible device can be used to treat, ameliorate, or improve any disorder in a subject that can be treated, ameliorated, or improved by a biocompatible device, which is well documented. Generally, the method comprises implanting the wound-healing-enhancing biocompatible device of invention in a subject in need thereof (e.g., a cardiovascular patient). Examples of such disorders include but not limited to cardiovascular diseases or conditions, orthopedic conditions or disorders, and diabetics.
The following examples illustrate rather than limit the embodiments of the present invention.
Methods:
In vivo angiogenic effects of FMOD were assessed by a chick embryo chorioallantoic membrane (CAM) assay, a Matrigel™ plug implant assay, and rodent primary closure wound models. In vitro angiogenic effects of FMOD were recorded by cell invasion and dimensional and topological parameters of human umbilical vein endothelial cells (HUVECs).
Results:
We provided evidence that FMOD significantly enhanced vascularization: firstly, FMOD boosted blood vessel formation on the CAM; secondly, FMOD markedly stimulated capillary infiltration into Matrigel™ plugs subcutaneously implanted in adult mice; and lastly, FMOD robustly promoted angiogenesis in multiple adult rodent cutaneous wound models. Furthermore, FMOD administration restored the vascularity of fmod−/− mouse wounds. In support of this, FMOD endorsed an angiogenesis-favored microenvironment in adult rodent wounds not only by upregulating angiogenic genes, but also by downregulating angiostatic genes. Additionally, FMOD significantly enhanced HUVEC invasion and tube-like structure formation in vitro.
Conclusion:
Altogether, we demonstrated that, in addition to reducing scar formation, FMOD also promotes angiogenesis. Since blood vessels organize and regulate wound healing, its potent angiogenic properties will further expand the clinical application of FMOD for cutaneous healing of poorly vascularized wounds.
Cutaneous wound healing is a natural response involving a complex cascade of cellular events to generate resurfacing, reconstitution, and restoration of tensile strength of injured skin. Unfortunately, the reasoning behind the failure of some cutaneous wounds to heal is still poorly understood due to the fact that wound healing is a complex, multifaceted process (1, 2). A fundamental problem of retarded wound healing is lack of a functional extracellular matrix (ECM) to stimulate, direct, and coordinate healing. For instance, deficiency of a single ECM molecule, fibromodulin (FMOD), in an adult mouse cutaneous wound model resulted in delayed dermal fibroblast migration, delayed granulation tissue formation, delayed wound closure, and subsequently increased scarring in an adult mouse cutaneous wound model (3). FMOD is a broadly distributed small leucine-rich proteoglycan (SLRP), which regulates ECM assembly, organization, and degradation via binding with collagens (4-10). FMOD plays an essential role in cell fate determination and fetal scarless wound healing (5, 11-14). In addition, our previous studies have demonstrated that FMOD controls significant aspects of adult cutaneous wound healing. Compared to their wild-type (WT) counterparts, FMOD-null (fmod−/−) mice have reduced fibronectin deposition, unorganized collagen architecture, altered transforming growth factor (TGF)-β signaling, and reduced dermal fibroblast infiltration followed by impeded angiogenesis (3, 4, 16). On the other hand, FMOD administration in both adenoviral and protein forms reduced scar formation in adult cutaneous wounds (17, 18). Specifically, we have demonstrated that FMOD significantly promoted fibroblast migration into the wound area, aiding timely wound closure and reduced scar formation (3, 16, 19). Because newly generated blood vessels provide nutrients to support active cells, promote granulation tissue formation, and facilitate clearance of debris (20-22), wound healing cannot occur without angiogenesis, a process of neovascular formation by endothelial cells (ECs). Our previous studies revealed that retarded fmod−/− mouse wound healing is associated with markedly reduced blood vessel regeneration (3), suggesting a direct relationship between FMOD and angiogenesis. In this study, the effects of FMOD on angiogenesis under both uninjured and wounded scenarios were investigated.
The in ovo CAM assay was performed as previously described (23, 24). Fertilized chicken eggs (Charles River Labs, North Franklin, Conn.) were incubated at 37° C. and 60% relative humidity in an egg incubator. On day 3, 5 ml albumin was withdrawn from the pointed end of the egg. Rectangle windows were cut into the shell as a portal of access for the CAM. On day 10, 2.0 mg/ml FMOD in 30 μl 1:3-diluted growth-factor-reduced Matrigel™ (BD Bioscience, Franklin Lakes, N.J.) was loaded on an autoclaved 5×5-mm polyester mesh layer (grid size: 530 μm; Component Supply Company, Fort Meade, Fla.) and incubated for 45 min at 37° C. for gel formation before transplantation onto the CAM. A non-FMOD phosphate buffered saline (PBS) control was transplanted onto the same CAM with a 1 cm distance. On day 13, CAMs were excised and photographed. The capillary area density directly under the mesh was measured by ImageJ (NIH, Bethesda, Md.) (25).
400 μl of growth-factor-reduced Matrigel™ containing 0 or 4.0 mg/ml FMOD was subcutaneously injected into the abdomen of adult 129/sv male mice, which were harvested with the overlying skin 14 days post-injection (26).
Four (per adult male 129/sv mouse) or six (per adult male Sprague-Dawley rat) full thickness, 10 mm×3 mm skin ellipses with the underlying panniculus carnosus muscle were excised from each animal. All wounds were separated by at least 2 cm to minimize adjacent wound effects. Each open wound edge was injected with 25 μl PBS or 0.4 mg/ml recombinant human FMOD in PBS (25 μl×2 edges=50 μl/wound) before being primarily closed. Sutures were removed at day 7 post-injury, and wounds were harvested at 14 days post-injury. Tissues were bisected centrally for histology or gene expression analysis (3, 4, 14, 16).
After fixation in 4% paraformaldehyde, samples were dehydrated, paraffin-embedded, and sectioned at 5-μm increments for Hematoxylin and Eosin (H&E), Picrosirius Red (PSR), and IHC staining (3, 4). PSR-coupled polarized light microscopy (PSR-PLM) was used to identify the wound area (3). Blood vessels were identified and quantitated by von Willebrand Factor (vWF; (Abeam Inc., Cambridge, Mass.).
RNA was isolated using RNeasy® Mini Kit with DNase treatment (Qiagen) (3, 16). 1.0 μg mouse RNA was used for reverse transcription with iScript™ Reverse Transcription Supermix for RT-qPCR (Bio-Rad Laboratories, Hercules, Calif.). Quantitative RT-PCR (qRT-PCR) was performed with TaqMan® Gene Expression Assays (Life Technologies) and SsoFast™ Probes Supermix with ROX (Bio-Rad Laboratories) on a 7300 Real-Time PCR system (Life Technologies). Meanwhile, 2.5 μg RNA isolated from adult rat wounds was injected into RT2 First Strand Kit (Qiagen) for reverse transcription. qRT-PCR was performed in a 96-well format of rat wound healing RT2 PCR Array (Qiagen) according to the manufacturer's protocol. Three different cDNA templates were tested. Concomitant glyceraldehyde 3-phosphate dehydrogenase (gapdh) was used as a housekeeping standard. Data analysis was achieved by the manufacturer's online services (http://perdataanalysis.sabiosciences.com/per/arrayanalysis.php).
Passages 3-6 human umbilical vein endothelial cells (HUVECs) were cultured in Medium 200PRF supplied with Low Serum Growth Supplement according to manufacturer instruction (Life Technologies).
Technologies Endothelial Tube Formation Assay protocol provided by Life Technologies (http://www.lifetechnologies.com/us/en/home/references/protocols/cell-and-tissue-analysis/cell-profilteration-assay-protocols/angiogenesis-protocols/endothelial-cell-tube-formation-assay.html) was used to assay TLS in vitro. Briefly, a 24-well plate was coated with 100 μl/well reduced growth factor basement membrane matrix for 1 h at 37° C. before being seeded with 2.5×104 HUVECs in Medium 200PRF supplied with different doses of FMOD. Five images per well and four wells per treatment were documented after 4 h by using an Olympus fluorescent microscope (Center Valley, Pa.). Images were assessed by recording dimensional and topological analyses with Image J (http://image.bio.methods.free.fr/ImageJ/?Angiogenesis-Analyzer-for-ImageJ.html&lang=en#outil_sommaire_0).
Cell invasion assay was performed in 24-well tissue culture plates using HTS Fluoroblok inserts with 8 μm pore size Fluorescence Blocking PET track-etched membranes (BD Bioscience). The upper surfaces of the inserts were coated with 100 μl of 2 mg/ml reduced growth factor basement membrane matrix (Geltrex®; Life Technologies) and placed into 24-well tissue culture plates containing 750 μl medium. 2.5×104 HUVECs in 500 μl medium with different doses of FMOD were added to each insert chamber and allowed to invade toward the underside of the membrane for 24 h. Non-invading cells were removed by wiping the upper side of the membrane with a cotton swab. Invaded cells were fixed and stained with 0.4 mg/ml 4′,6-diamino-2-phenlindole (DAPI; Sigma-Aldrich, St. Louis, Mo.) before counting (3).
Statistical significance was performed by OriginPro 8 (Origin Lab Corp., Northampton, Mass.), including one-way ANOVA, paired t-test, two-sample t-test, and Mann-Whitney analyses. P-values less than 0.05 were considered statistically significant.
FMOD promotes vascularization in uninjured scenarios FMOD administrated CAMs showed a 1.5-times greater proportion of blood vessels with large diameters than the PBS control (
FMOD is important for angiogenesis during wound healing In agreement with our previous studies at day 7 post-injury (3), vascular generation in adult fmod−/− mouse skin wounds at day 14 post-injury was diminished by approximately 50% as compared to the age-matched WT wounds (
Double-transgenic mice overexpressing vascular endothelial growth factor (Vegf) and angiopoietin 1 (Angpt1) in skin showed a greater quantity and size of blood vessels (28). Vegf is massively produced by the epidermis during wound healing and has strong stimulating effects on angiogenesis via enhancement of microvascular permeability and stimulation of EC proliferation and migration (29-33). There was no meaningful difference in Vegf expression between adult WT and fmod−/− mouse unwounded skin tissues; however, vegf levels in WT wounds significantly increased at day 7 and 14 post-injury (
Numerous angiogenic and angiostatic factors have been identified in the past (37, 38). In order to further enrich our knowledge of how FMOD affects angiogenesis-related genes during wound healing, a RT2 PCR Array for rat wound healing (Qiagen, Valencia, Calif.) was employed for high-throughput gene expression analysis in an adult rat cutaneous wound model. As seen in the adult mouse data shown above, FMOD administration elevated both angpt1 and vegf expression (
To explore the direct effects of FMOD on EC spouting, the initial step of angiogenesis (21, 54), primary human umbilical vein endothelial cells (HUVECs) were seeded in Geltrex® matrix (Life Technologies, Grand Island, N.Y.), which contains laminin, collagen IV, entactin, and heparin sulfate proteoglycans to model a wound healing angiogenic situation. HUVECs spontaneously acquired elongated morphology and formed a capillary network in the gel, clearly visible by 3 hours post-seeding (
Angiogenesis, a process of neovascular formation from pre-existing blood vasculature by sprouting, splitting, and remodeling of the primitive vascular network, results from multiple signals acting on ECs regulated by diverse groups of growth factors and ECM molecules (32, 44, 54). Until now, most studies on angiogenesis focused on soluble factors such as Vegf and Fgf2 (30-33, 42). However, increasing reports reveal that cell-ECM interaction is also critical for EC growth, differentiation, apoptosis, and response to soluble growth factors (10, 56, 57). For instance, blockage of EC-ECM interactions inhibits neovascularization in vivo and TLS formation in vitro (58-60). These findings indicate that successful angiogenesis requires a dynamic temporally and spatially regulated interaction between ECs, angiogenic factors, and surrounding ECM molecules such as SLRPs (21, 22, 32).
SLRPs are a family of proteins, including decorin, lumican, and FMOD, that are present within the ECM of all tissues (4-10). Since recent studies have shown that SLRPs interact with a diversity of cell surface receptors, cytokines, growth factors, and other ECM components resulting in modulation of cell-ECM cross talk and multiple biological processes (10-15), the common functionalities of SLRPs are far beyond their structural functions in the ECM (10, 15, 61). Specifically, intensive studies present a controversial function of decorin in angiogenesis: decorin is angiogenic during development and normal wound healing but is anti-angiogenic during tumor angiogenesis due to its ability to interfere with thrombospondin-1, suppress endogenous tumor Vegf production, and evoke stabilization of pericellular fibrillar matrix (10). Additionally, Niewiarowska et al. revealed that lumican inhibits angiogenesis by reducing proteolytic activity of ECs (62). However, unlike decorin and lumican, our current study revealed that FMOD is an angiogenic ECM molecule. Although FMOD and lumican present close homology and share the same binding region on type I collagen (63-65), their diverse influences on angiogenesis as well as epithelial migration (3, 16, 66) further support the hypothesis that FMOD and lumican do not appear to be functionally redundant, especially during cutaneous wound healing.
In this study, we demonstrated that not only did FMOD markedly enhance vasculogenesis during development, as documented by the in ovo CAM assay, but it also significantly stimulated angiogenesis as evidenced by the Matrigel™ plug assay as well as capillary density measurements in adult rodent cutaneous wound models. Additionally, impaired wound angiogenesis in fmod−/− mice could be restored by exogenous FMOD administration. At the cellular level, we confirmed that FMOD boosted HUVEC migration/invasion and TLS formation in vitro. Our previous studies also found that, without considerable influence on EC proliferation, FMOD promoted EC cell adhesion, spreading, and actin stress fiber formation for vascularization in vitro (24). Thus, FMOD is an angiogenic ECM molecule that directly modulates EC behaviors. In addition to ECs, mural cells (such as fibroblasts and pericytes) and inflammatory cells (such as monocytes and mast cells) also contribute to wound angiogenesis (54, 67). By stimulating expression of various angiogenic factors including angpt1, vegf tgfα, fgf2, pdgfα, and csf3, FMOD also activated these angiogenesis-related cells in vivo during the wound healing process. In contrast, Ifnγ and Plg are anti-angiogenic, pro-inflammation molecules involved in wound healing (47-50, 52, 53, 68, 69). Additionally, Plg in particular also plays an important role in re-epithelialization, since keratinocyte migration over the wound is delayed in Plg-deficient mice (70).
In this study, FMOD administration reduced ifnγ and plg levels and increased angiogenesis in adult rodent wounds, which is highly correlated with our previous observation that cutaneous wounds of fmod−/− mice exhibited extended inflammation, elevated epithelial migration, and insufficient angiogenesis (3, 16). Moreover, TOβ1, a multipotent growth factor that regulates wound healing, promotes endothelial cell differentiation in a Vegf-independent manner at early stages of development, but inhibits sprouting angiogenesis in differentiated ECs (51). Thus, lower tgfβ1 transcription after wound closure could also contribute to enhanced angiogenesis in FMOD-treated wounds. Consistent with previous studies(24, 71), FMOD administration induced a pro-angiogenic microenvironment for wound healing in vivo by stimulating angiogenic factors and reducing angiostatic molecules.
In summary, as one of the pioneer groups investigating the influence of SLRPs on wound healing, we elucidated the angiogenic properties of FMOD in wounded scenarios, which function at least partially by promoting EC activation and infiltration in the wound area. While translation from the pre-clinical to the clinical setting can be difficult due to an increased number of external factors such as bacterial inhibition, taken together, current studies suggest that FMOD maintains the potential to be an attractive therapeutic candidate for wound management, especially for patients suffering from impaired wound healing due to aberrant cellular infiltration and insufficient angiogenesis, such as in the cases of diabetic wounds (72-74).
Cutaneous scars affect over 100 million patients annually, and are major concerns for those suffering from debilitating medical conditions. Unfortunately, the current methods of scar treatment and reduction are minimally effective or have undesirable side effects. By using fetal rodent cutaneous wound models, we demonstrated that fibromodulin (FMOD) is essential for scarless fetal-type repair. FMOD also exhibited potent anti-scarring effects in loss- and gain-of-function rodent models and increased wound tensile strength in adult rodent and two porcine models that simulate normal and hypertrophic human cutaneous repair. Instead of simply antagonizing, FMOD orchestrated transforming growth factor (TGF)-beta signaling in an isoform-specific and signal transduction-specific manner. Thus, FMOD induced fibroblast migration, differentiation, and contraction, which accelerated timely, wound closure, and inhibited fibrotic extracellular matrix expression, which promoted reduced scar formation. Moreover, FMOD stimulated interleukin 1b expression, a known accelerant of myofibroblast apoptosis and the principal cell type implicated in pathological scarring. Overall, FMOD drives cellular migration, differentiation, and contraction, as well as myofibroblast apoptosis through diverse signaling pathways to promote optimal repair. These findings strongly suggest the potential clinical utility of FMOD for prevention and treatment of human scarring such as hypertrophic scars, keloids, and other fibrotic conditions.
Those skilled in the art will know, or be able to ascertain, using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. These and all other equivalents are intended to be encompassed by the following claims.
The present application is a continuation-in-part of PCT/US2015/064826, filed on Dec. 9, 2015, which claims the benefit of U.S. provisional application No. 62/089,756, filed on Dec. 9, 2014. The present application also claims the benefit of U.S. provisional application No. 62/265,271, filed on Dec. 9, 2015. Teaching of the priority applications are incorporated herein in its entirety by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62089756 | Dec 2014 | US | |
| 62265271 | Dec 2015 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/US2015/064826 | Dec 2015 | US |
| Child | 15374620 | US |
