Bone graft substitute composition

Information

  • Patent Grant
  • 8968465
  • Patent Number
    8,968,465
  • Date Filed
    Thursday, January 16, 2014
    11 years ago
  • Date Issued
    Tuesday, March 3, 2015
    9 years ago
Abstract
A composition includes calcium sulfate hemihydrate, stearic acid, an accelerant, and a mixing solution. The composition can be injected, e.g., through a needle, and is capable of setting, e.g., in vivo, in a relatively short period of time to a relatively high hardness.
Description
TECHNICAL FIELD

The invention relates to bone graft substitute compositions.


BACKGROUND

Compositions containing calcium sulfate can be used as filler for voids or defects defined by bone. In some embodiments, the compositions can promote bone growth.


SUMMARY

The invention relates to bone graft substitute compositions. In one aspect, the invention features a composition including calcium sulfate, such as calcium sulfate hemihydrate, a binder, an accelerant, and a mixing solution.


In another aspect, the invention features a method including providing a mixture having calcium sulfate, such as calcium sulfate hemihydrate, a binder, and an accelerant, and contacting the mixture with a mixing solution.


Embodiments of the invention may include one or more of the following features. The calcium sulfate includes calcium sulfate hemihydrate. The binder includes stearic acid, hydroxypropylmethylcellulose (HPMC), hydroxymethylcellulose (HPC), and/or hyaluronic acid. The accelerant includes calcium sulfate dihydrate, and/or an ionic salt such as potassium sulfate or sodium sulfate. The mixing solution includes a saline solution.


Embodiments may have one or more of the following advantages. The composition is capable of setting or hardening in a relatively short time. In embodiments, the composition can harden to about 4 MPa in about 5-10 minutes. The composition is capable of setting or hardening in vivo. The composition can be injected through a needle, e.g., an 11-13 gauge needle up to about 10 cm long.


Other features and advantages of the invention will be apparent from the description of the preferred embodiments thereof and from the claims.







DETAILED DESCRIPTION

A bone graft substitute composition includes calcium sulfate, such as calcium sulfate hemihydrate (CaSO4.½H2O), a binder, such as stearic acid, a material that accelerates hardening of the composition (“an accelerant”), and a mixing solution. In some embodiments, the calcium sulfate, the binder, and the accelerant are provided as a mixture of powders to which the mixing solution is added to form the composition. The composition can be delivered to a target site by injecting the composition through a needle. The composition can harden in vivo, e.g., such that the hardened composition is capable of supporting orthopedic hardware.


The calcium sulfate is preferably calcium sulfate hemihydrate, CaSO4.½H2O. Without wishing to be bound by theory, it is believed that during use, e.g., after mixing the powder mixture with the mixing solution, the calcium sulfate hemihydrate is converted, e.g., changes crystalline form, into calcium sulfate dihydrate (CaSO4.2H2O), which hardens the composition. Calcium sulfate dihydrate is capable of being sorbed by the body. In some embodiments, the mixture of powders includes greater than about 90 weight percent of calcium sulfate, e.g., calcium sulfate hemihydrate. The mixture may include greater than 90, 91, 92, 93, 94, 95, 96, 97, 98, or 99 weight percent of calcium sulfate hemihydrate; and/or less than 100, 99, 98, 97, 96, 95, 94, 93, 92, or 91 weight percent of calcium sulfate hemihydrate. Methods of making a calcium sulfate hemihydrate is described in U.S. Pat. Nos. 5,614,206; 5,807,567; and 6,030,636, all hereby incorporated by reference in their entirety.


Without wishing to be bound by theory, it is believed that the binder provides the composition with a consistency that helps the composition to flow, e.g., to be injectable. It is believed that, for example, stearic acid may also make the composition relatively hydrophobic, for example, which may lubricate the inner wall of a syringe and enhance flow of the composition. In some embodiments, the mixture of powders includes between about 1 and 2, e.g., about 1.5-2.0, weight percent of the binder. The mixture may include greater than 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, or 1.9 weight percent of the binder; and/or less than 2.0, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, or 1.1 weight percent of the binder. Examples of binders include stearic acid, hydroxypropylmethylcellulose (HPMC), hydroxymethylcellulose (HPC), and hyaluronic acid. Mixtures of two or more binders may be used.


Without wishing to be bound by theory, the accelerant is believed to enhance, e.g., accelerate, the conversion of calcium sulfate hemihydrate to calcium sulfate dihydrate. In particular, it is believed that particles of the accelerant act as crystallization nucleation sites for the conversion of calcium sulfate hemihydrate to calcium sulfate dihydrate. Examples of accelerants include calcium sulfate dihydrate, potassium sulfate, or sodium sulfate. Other examples include ionic salts. A preferred accelerant is calcium sulfate dihydrate crystals (available from U.S. Gypsum) coated with sucrose (available from VWR Scientific Products). A process of stabilizing the dihydrate crystals by coating with sucrose is described in U.S. Pat. No. 3,573,947, hereby incorporated by reference in its entirety. In some embodiments, the mixture of powders includes between about 0.1 and 0.5 weight percent of the accelerant. The mixture may include greater than 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, or 0.45 weight percent of the accelerant; and/or less than 0.50, 0.45, 0.40, 0.35, 0.30, 0.25, 0.20, or 0.15 weight percent of the accelerant. Mixtures of two or more accelerants can be used.


The mixing solution is generally selected to provide the composition with a desired consistency and hardening time. Examples of a mixing solution include water, e.g., sterile water, solutions containing inorganic salts, or cationic surface-active agents including sodium chloride, saline, e.g., phosphate buffered saline, potassium chloride, sodium sulfate, potassium sulfate, EDTA, ammonium sulfate, ammonium acetate, and sodium acetate. A specific example of a mixing solution is 0.9% NaCl saline solution (available from Baxter). In some embodiments, for a 25 g mixture of powders, preferably about 8-10 cc of mixing solution is added to the mixture to form a composition. Mixtures of two or more mixing solutions can be used.


The mixing solution can further include, for example, bone marrow aspirate, platelet concentrate, blood, pharmaceutical additives in solution, or combinations of these materials. Examples of additives are medicaments or pesticides. Examples of medicaments are antibiotics, chemotherapeutic agents, growth factors, and analgesics. Examples of antibiotics are tetracycline hydrochloride, vancomycin, cephalosporins, and aminoglycocides such as tobramycin and gentamicin. Examples of chemotherapeutic agents are cis-platinum, ifosfamide, methotrexate, and doxorubicin hydrochloride (Adriamycin®). Examples of growth factors are transforming growth factor beta (TGF-Beta), bone morphogenic protein (BMP), basic fiberblast growth factor, platelet-derived growth factor, and other polypeptide growth factors. Examples of analgesics are anesthetics such as lidocaine hydrochloride (Xylocaine®), bipivacaine hydrochloride (Marcaine®), and non-steroidal anti-inflammatory drugs such as ketorolac tromethamine (Toradol®). Certain mixing solutions can affect, e.g., delay, the hardening properties of the composition.


The composition can be formed by providing the mixture of powders (e.g., calcium sulfate hemihydrate, stearic acid, and calcium sulfate dihydrate) and contacting, e.g., mixing, the mixture with a mixing solution (e.g., NaCl saline) to form the composition. The composition may be a conforming material having a paste-like consistency, e.g., like Plaster of Paris. The material can be injected into a target site, for example, to fill into cracks or voids. In some embodiments, the material can be injected through an 11 to 13-gauge needle up to, for example, 10 cm long. The material is capable of setting to a hardness comparable to or greater than bone within about 5-10 minutes, e.g., greater than 5, 6, 7, 8, or 9 minutes, and/or less than 10, 9, 8, 7, or 6 minutes. The material can have a Vicat set time of about 5-10 minutes, e.g., 5-6 minutes. The material is capable of hardening to about >4 MPa.


The hardened composition can be used for intra-operative support of hardware, such as orthopedic hardware, e.g., bone plates, distal radius hardware, and hardware used for tibial plateau fractures.


Other Embodiments

In some embodiments, the composition further includes a bioactive agent. Examples of bioactive agents include demineralized bone matrix, growth factors, hyaluronic acid, bone morphogenic proteins, bone autograft, and bone marrow, etc. The composition may include sodium bicarbonate. For example, the composition may include 0.1-2% sodium bicarbonate by weight to provide a porous structure in the resultant composition.


Alternatively or in addition, the bone graft substitute composition may include one or more additives such as an antiviral agent, an antimicrobial agent, an antibiotic agent, an amino acid, a peptide, a vitamin, an inorganic element, a protein synthesis co-factor, a hormone, an endocrine tissue, a synthesizer, an enzyme, a polymer cell scaffolding agent with parenchymal cells, an angiogenic drug, demineralized bone powder, a collagen lattice, an antigenic agent, a cytoskeletal agent, mesenchymal stem cells, a bone digester, an antitumor agent, a cellular attractant, fibronectin, a growth hormone, a cellular attachment agent, an immunosuppressant, a nucleic acid, a surface active agent, calcium phosphate materials, such as hydroxyapatite or tricalcium phosphate, a penetration enhancer, a bone allograft, cancellous bone chips (an osteoconductive substrate), and chunks, shards, and/or pellets of calcium sulfate.


The bone graft substitute composition can also be used as a carrier, for example, by mixing it with other materials, such as, for example, allografts, antibiotics, growth factors, cancellous bone chips, or synthetically derived or naturally derived chips of minerals such as calcium phosphate or calcium carbonate. This can provide the composition with versatility and flexibility by allowing a user to formulate a mixed composition according to a desired application.


The following example is illustrative and not intended to be limiting.


EXAMPLE

A 25-gram mixture of powders was formed having 98.08 wt % of CaSO4.½H2O, 1.77 wt % of stearic acid (triple pressed powder, available from VWR Scientific Products), and 0.15 wt % of CaSO4.2H2O. About 9 cc of mixing solution (0.9% NaCl saline) was added to the mixture of powders, and mixed together to form a composition having a paste-like consistency.


The composition could be injected through a 6 cm long, 11-gauge needle. After about 7 minutes, the composition hardened, e.g., comparable to the hardness of bone. More specifically, the composition hardened to about 8 MPa (8.17 MPa±0.23, n=3) after after about twenty minutes; to about 17 MPa (16.54 MPa±1.05, n=8) after about one hour; and to about 35 MPa (34.94 MPa±4.04, n=5) after about 24 hours.


As described above, the composition can also harden in vivo. Following procedures similar to ASTM-F451, cylindrical samples (6 mm diameter, 12 mm high) of the composition were submerged in bovine calf serum to simulate in vivo conditions. The hardness of the samples was measured at different times. After about seven minutes, the composition hardened to about 1 MPa (1.04 MPa±0.29, n=3). After about twenty minutes, the composition hardened to about 4 MPa (3.82 MPa±0.87, n=3). After about one hour, the composition hardened to about 15 MPa (14.94 MPa±0.82, n=8). After about 24 hours, the composition hardened to about 10 MPa (10.59±0.73, n=8).


The amount of mixing solution added to the mixture of powders can affect the time the composition takes to set, i.e., the set time. Increasing the amount of mixing solution can increase the set time. For example, in embodiments, adding more than 12 cc of saline to the above 25-gram mixture may delay hardening to over 30-40 minutes. Decreasing the amount of mixing solution added to the mixture of powders can reduce the set time, but injecting the composition can be relatively difficult. Other embodiments are within the claims.

Claims
  • 1. A bone graft substitute composition kit, comprising: a powder mixture comprising greater than about 90 weight percent calcium sulfate hemihydrate, an accelerant for accelerating conversion of calcium sulfate hemihydrate to calcium sulfate dihydrate, the accelerant present in an amount of less than about 0.5 percent by weight of the powder mixture, and stearic acid in an amount of at least about 1.0 percent by weight of the powder mixture; an aqueous mixing solution; and an additional component selected from the group consisting of antiviral agents, antimicrobial agents, antibiotic agents, surface-active agents, antitumor agents, demineralized bone matrix, mesenchymal stem cells, bone marrow, growth factors, calcium phosphate materials, sodium bicarbonate, bone allograft, cancellous bone chips, pellets of calcium sulfate, and mixtures thereof.
  • 2. The bone graft substitute composition kit of claim 1, wherein the powder mixture comprises greater than about 95 weight percent calcium sulfate hemihydrate.
  • 3. The bone graft substitute composition kit of claim 1, wherein the aqueous mixing solution is a saline solution.
  • 4. The bone graft substitute composition kit of claim 1, wherein the aqueous mixing solution comprises at least one inorganic salt or at least one cationic surface-active agent.
  • 5. The bone graft substitute composition kit of claim 1, wherein the powder mixture comprises about 0.1 to about 0.5 weight percent of said accelerant.
  • 6. The bone graft substitute composition kit of claim 1, wherein the powder mixture comprises about 1.0 to about 2.0 weight percent of stearic acid.
  • 7. The bone graft substitute composition kit of claim 1, wherein the bone graft substitute composition produced by mixing said powder mixture and said aqueous mixing solution has a Vicat set time of about 5 to about 10 minutes.
  • 8. The bone graft substitute composition kit of claim 1, wherein the accelerant is present in an amount of about 0.1 to about 0.5 weight percent, and the stearic acid is present in an amount of about 1.0 to about 2.0 weight percent.
  • 9. The bone graft substitute composition kit of claim 1, wherein the accelerant is present in an amount of less than about 0.3 percent by weight of the powder mixture, and stearic acid in an amount of at least about 1.5 percent by weight of the powder mixture.
  • 10. The bone graft substitute composition kit of claim 1, wherein the accelerant is selected from calcium sulfate dihydrate and calcium sulfate dihydrate coated with sucrose.
  • 11. The bone graft substitute composition kit of claim 1, wherein the accelerant is calcium sulfate dihydrate coated with sucrose.
  • 12. The bone graft substitute composition kit of claim 1, wherein the bone graft substitute composition produced by mixing said powder mixture and said aqueous mixing solution is injectable through a needle.
  • 13. The bone graft substitute composition kit of claim 1, wherein the bone graft substitute composition kit further comprises sodium bicarbonate and the bone graft substitute composition produced by mixing said powder mixture and said aqueous mixing solution has a porous structure.
  • 14. The bone graft substitute composition kit of claim 1, wherein the additional component comprises demineralized bone matrix.
  • 15. The bone graft substitute composition kit of claim 1, wherein the additional component comprises an antibiotic agent.
  • 16. The bone graft substitute composition kit of claim 15, wherein the antibiotic is selected from the group consisting of tetracycline hydrochloride, vancomycin, cephalosporins, tobramycin, and gentamicin.
  • 17. The bone graft substitute composition kit of claim 1, wherein the additional component comprises a growth factor.
  • 18. The bone graft substitute composition kit of claim 17, wherein the growth factor is selected from the group transforming growth factor beta, bone morphogenic protein, basic fiberblast growth factor, and platelet-derived growth factor.
  • 19. The bone graft substitute composition kit of claim 1, wherein the additional component comprises an antitumor agent.
  • 20. The bone graft substitute composition kit of claim 1, wherein the additional component comprises a calcium phosphate material.
CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No. 11/739,416, filed on Apr. 24, 2007, which is a continuation of U.S. patent application Ser. No. 10/402,192, filed on Mar. 28, 2003, now U.S. Pat. No. 7,211,266, which claims priority under 35 U.S.C. §119(e) to U.S. Patent Application No. 60/368,924, filed on Mar. 29, 2002, the entire contents of which are hereby incorporated by reference.

US Referenced Citations (104)
Number Name Date Kind
3573947 Kinkade et al. Apr 1971 A
3947285 Jones et al. Mar 1976 A
4430760 Smestad Feb 1984 A
4526619 Ohi et al. Jul 1985 A
4568536 Kronenthal et al. Feb 1986 A
4595713 St. John Jun 1986 A
4596574 Urist Jun 1986 A
4612009 Drobnik et al. Sep 1986 A
4619655 Hanker et al. Oct 1986 A
4650665 Kronenthal et al. Mar 1987 A
4681763 Nathanson et al. Jul 1987 A
4820306 Gorman et al. Apr 1989 A
4880660 Aasen et al. Nov 1989 A
4882149 Spector Nov 1989 A
4892734 Leonard Jan 1990 A
4975526 Kuberasampath et al. Dec 1990 A
4994030 Glowczewskie, Jr. et al. Feb 1991 A
4994264 Verdon et al. Feb 1991 A
5061286 Lyle Oct 1991 A
5073373 O'Leary et al. Dec 1991 A
5147403 Gitelis Sep 1992 A
5162114 Kuberasampath et al. Nov 1992 A
5219897 Murray Jun 1993 A
5236456 O'Leary et al. Aug 1993 A
5236971 Murray Aug 1993 A
5264214 Rhee et al. Nov 1993 A
5284655 Bogdansky et al. Feb 1994 A
5290558 O'Leary et al. Mar 1994 A
5298254 Prewett et al. Mar 1994 A
5306304 Gendler Apr 1994 A
5314476 Prewett et al. May 1994 A
5320844 Liu Jun 1994 A
5336699 Cooke et al. Aug 1994 A
5356629 Sander et al. Oct 1994 A
5366507 Sottosanti Nov 1994 A
5385887 Yim et al. Jan 1995 A
5405390 O'Leary et al. Apr 1995 A
5417975 Lussi et al. May 1995 A
5425769 Snyders et al. Jun 1995 A
5439684 Prewett et al. Aug 1995 A
5462722 Liu et al. Oct 1995 A
5482551 Morris et al. Jan 1996 A
5484601 O'Leary et al. Jan 1996 A
5507813 Dowd et al. Apr 1996 A
5510396 Prewett et al. Apr 1996 A
5512610 Lin Apr 1996 A
5531791 Wolfinbarger, Jr. Jul 1996 A
5569308 Sottosanti Oct 1996 A
5573771 Geistich et al. Nov 1996 A
5578662 Bennett et al. Nov 1996 A
5614206 Randolph et al. Mar 1997 A
5618549 Patat et al. Apr 1997 A
5676146 Scarborough Oct 1997 A
5681873 Norton et al. Oct 1997 A
5697981 Ison et al. Dec 1997 A
5700289 Breitbart et al. Dec 1997 A
5707962 Chen et al. Jan 1998 A
5727945 Dannenbaum Mar 1998 A
5756127 Grisoni et al. May 1998 A
5763416 Bonadio et al. Jun 1998 A
5766618 Laurencin et al. Jun 1998 A
5769897 Harte Jun 1998 A
5788976 Bradford Aug 1998 A
5794402 Dumlao et al. Aug 1998 A
5807567 Randolph et al. Sep 1998 A
5824087 Aspden et al. Oct 1998 A
5830493 Yokota et al. Nov 1998 A
5861445 Xu et al. Jan 1999 A
5899939 Boyce et al. May 1999 A
5910315 Stevenson et al. Jun 1999 A
5948426 Jefferies Sep 1999 A
5948428 Lee et al. Sep 1999 A
5964805 Stone Oct 1999 A
5972368 McKay Oct 1999 A
5981828 Nelson et al. Nov 1999 A
6023806 Dumlao et al. Feb 2000 A
6030635 Gertzman et al. Feb 2000 A
6030636 Randolph et al. Feb 2000 A
6037519 McKay Mar 2000 A
6044607 Dumlao et al. Apr 2000 A
6051247 Hench et al. Apr 2000 A
6056970 Greenawalt et al. May 2000 A
6071530 Polson et al. Jun 2000 A
6083522 Chu et al. Jul 2000 A
6108998 Dumlao et al. Aug 2000 A
6118043 Nies et al. Sep 2000 A
6171388 Jobbins Jan 2001 B1
6224635 Ricci et al. May 2001 B1
6478825 Winterbottom et al. Nov 2002 B1
6645333 Johnson et al. Nov 2003 B2
6652887 Richelsoph et al. Nov 2003 B1
6676785 Johnson et al. Jan 2004 B2
6753007 Haggard et al. Jun 2004 B2
6998128 Haggard et al. Feb 2006 B2
7291179 Miller et al. Nov 2007 B2
7371408 Petersen et al. May 2008 B1
7371409 Petersen et al. May 2008 B2
7371410 Petersen et al. May 2008 B2
7658768 Miller et al. Feb 2010 B2
7972630 Lidgren Jul 2011 B2
20020016636 Ricci et al. Feb 2002 A1
20020071827 Petersen et al. Jun 2002 A1
20030096718 Sugimoto et al. May 2003 A1
20030143258 Knaack et al. Jul 2003 A1
Foreign Referenced Citations (13)
Number Date Country
196 20 117 Jul 1997 DE
2 093 348 Sep 1982 GB
WO 8904646 Jun 1989 WO
WO 9639203 Dec 1996 WO
WO 9840113 Sep 1998 WO
WO 9915150 Apr 1999 WO
WO 0045734 Aug 2000 WO
WO 0074690 Dec 2000 WO
WO 0176649 Oct 2001 WO
WO 0205750 Jan 2002 WO
WO 03024316 Mar 2003 WO
WO 03030956 Apr 2003 WO
WO 03045455 Jun 2003 WO
Non-Patent Literature Citations (10)
Entry
Adkisson et al., “Rapid Quantitative bioassay of Osteoinduction”, Journal of Orthopaedic Research, 18:503-511, 2000.
“Advances in Biomaterials for Bone Regeneration”, Orthopedics, vol. 26, No. 5/Supplement, May 2003.
Betz, M.D., Randall R. “Limitations of Autograft and Allograft. New Synthetic Solutions”, Orthopedics, vol. 25, No. 5, Supplement May 2002.
Biomaterials Tutorial, www.btec.cmu.edu/tutorial/biomaterials/biomaterials.htm, Undated.
“Bone Graft Substitutes Safe, Effective”, AMA Science News Media Briefings, Dec. 6, 2001.
Greenwald et al., “Bone-Graft Substitutes: Facts, Fictions, and Applications”, The Journal of Bone & Joint Surgery, JBJS Org., vol. 83-A, Supplement 2, Part 2, 2001.
Grimandi et al., “In vitro evaluation of a New Injectable Calcium Phosphate Material”, J. Biomed. Mater Res., 1998, pp. 660-666, vol. 39, John Wiley & Sons, Inc.
Hanker et al., “Setting of Composite Hydroxylaptie/Plaster Implants with Blood for Bone Reconstruction”, Proceedings of the 44th Annual Meeting of the Electron Microscopy Society of America, 1986.
Kelly, Ph.D., Evelyn B., “New Frontiers in Bone Grafting”, Orthopaedic Technology Review, vol. 2, No. 9, Oct. 2000.
Turner et al.., “Radiographic and Histologic Assessment of Calcium o Sulfate in Experimental Animal Models and Clinical Use as a Resorbable Bone-Graft Substitute, a Bone-Graft Expander, and a Method for Local Antibiotic Delivery”, The Journal of Bone and Joint Surgery, Incorporated, vol. 83-A, Supp. 2, Part 1, 2001.
Related Publications (1)
Number Date Country
20140134227 A1 May 2014 US
Provisional Applications (1)
Number Date Country
60368924 Mar 2002 US
Continuations (2)
Number Date Country
Parent 11739416 Apr 2007 US
Child 14156850 US
Parent 10402192 Mar 2003 US
Child 11739416 US