Patent Application
20190275003
The presently-disclosed subject matter generally relates to methods and products for encapsulation of, delivery of, and/or treatment with rolipram. In particular, certain embodiments of the presently-disclosed subject matter relate to fusogenic lipid vesicles (FLVs), encapsulation of rolipram therein, and treatment methods using the encapsulated rolipram.
Despite extensive research, alcohol abuse remains one of the most common causes of acute and chronic liver disease in the United States and worldwide. In Western countries, up to 50% of end-stage liver disease cases have alcohol as a major etiologic factor, with excessive alcohol consumption being the third leading preventable cause of death in the United States. Alcohol-related deaths, excluding accidents/homicides, accounted for 22,073 deaths in the United States in 2006. In particular, alcoholic liver disease (ALD), which accounted for 13,000 of those 22,073 alcohol related deaths, remains a major cause of liver related mortality in the U.S. The mortality of this liver disease is more than that of many major forms of cancer (e.g., breast, colon, and prostate). For example, survival rates of 5 and 10 years for alcoholic cirrhosis have been reported by some groups at 23% and 7%, respectively. Projections indicate that the annual costs of this problem exceed 2.5 billion dollars in the U.S. However, as no drug therapy has yet been approved by the Food and Drug Administration (FDA) for any stage of ALD, the only currently accepted approach to ALD by most physicians is abstinence and optimal nutrition.
One major feature of ALD includes abnormal cytokine metabolism. For example, dysregulated tumor necrosis factor-α (TNF) metabolism has been identified in severe alcoholic hepatitis (AH). It was observed that peripheral monocytes (which produce the overwhelming majority of systemic circulating TNF and are a surrogate marker for Kupffer cells) from AH patients spontaneously produced significantly more TNF in response to an endotoxin (LPS) stimulus. Additionally, increased serum TNF concentrations in ALD were reported and values correlated with disease severity and mortality. More specifically, elevated serum concentrations of TNF and TNF-inducible proinflammatory cytokines/chemokines, such as interleukin (IL)-8 and IL-18, have been reported in patients with alcoholic hepatitis and/or cirrhosis. These elevated levels correlate with markers of the acute phase response, reduced liver function, and poor clinical outcome.
While several pharmacological therapies have been tested in patients with alcoholic liver disease, to date, none has shown consistent improvement in the course of alcoholic hepatitis with and without superimposed cirrhosis. For example, although anti-TNF antibodies and soluble receptors are FDA approved and used clinically with excellent results for chronic inflammatory diseases such as Crohn's disease, rheumatoid arthritis, and others, in the context of liver disease, a complete inhibition of TNF could potentially impair liver regeneration with detrimental consequences. Initial small trials of anti-TNF antibody in AH seemed positive, however, a large French multicenter trial using anti-TNF antibody plus prednisone, was stopped due to increased mortality. Also, a U.S. multicenter trial with a TNF-soluble receptor in AH showed no benefit. Furthermore, potential side effects and expense are associated with anti-TNF therapy, and these effects may limit their use in ALD.
As an alternative to antibodies and soluble receptors, it has been shown that LPS-inducible TNF expression by monocytes/macrophages is critically regulated by the intracellular cyclic adenosine monophosphate (cAMP) levels. The instant inventors recently demonstrated that chronic ethanol exposure of monocytes/macrophages (including Kupffer cells) decreases both basal and LPS-stimulated cyclic adenosine monophosphate (cAMP) levels by up-regulating phosphodiesterase (PDE) 4 expression, which leads to the enhancement of LPS-inducible TNF production. Of the PDE4 A, B and D isoforms predominantly expressed in monocytes/macrophages, it has been established that PDE4B is involved in LPS-induced signaling mediated by TLR4 and is essential for LPS-induced TNF expression.
Phosphodiesterase (PDE) inhibitors, which increase cAMP levels, have been extensively studied and have been demonstrated to effectively inhibit TNF production in vivo and in vitro. Importantly, PDE4 inhibitors also have also been demonstrated to up-regulate cytokine IL-10, which has anti-inflammatory and anti-fibrotic properties. Accordingly, PDE inhibitors may represent possible therapies for chronic inflammatory processes. For example, in human clinical studies, Pentoxifylline (PTX), a non-specific PDE inhibitor, decreased mortality in patients with AH. PTX has also been shown to attenuate liver injury and fibrosis in several animal models. In addition, the instant inventors recently showed the pathogenic role of PDE4 enzymes in the development of cholestatic liver injury and fibrosis, along with significant protection by PDE4 specific inhibitor rolipram. Further, the instant inventors have reported that rolipram-mediated inhibition of PDE4 significantly down-regulates LPS-inducible TNF. However, the therapeutic use of PDE4 inhibitors (including rolipram) to treat alcohol-induced hepatic inflammation and liver disease is precluded by severe dose-associated side effects including severe nausea and emesis caused by the inhibition of PDE4 in the central nervous system (CNS) and/or the increased cAMP levels in the CNS. The systemic therapeutic doses of rolipram or other PDE4 inhibitors required to reduce TNF expression in ALD will consistently produce side effects.
Accordingly, there exists a need for products and methods that effectively treat ALD without the prohibitive side effects of current treatments.
The presently-disclosed subject matter meets some or all of the above-identified needs, as will become evident to those of ordinary skill in the art after a study of information provided in this document.
This summary describes several embodiments of the presently-disclosed subject matter, and in many cases lists variations and permutations of these embodiments. This summary is merely exemplary of the numerous and varied embodiments. Mention of one or more representative features of a given embodiment is likewise exemplary. Such an embodiment can typically exist with or without the feature(s) mentioned; likewise, those features can be applied to other embodiments of the presently-disclosed subject matter, whether listed in this summary or not. To avoid excessive repetition, this summary does not list or suggest all possible combinations of such features.
In some embodiments, the presently-disclosed subject matter includes a composition for treating liver inflammation, the composition comprising a biologically active phosphodiesterase 4 (PDE4) inhibitor. In some embodiments, the composition further comprises a liposome encapsulating the inhibitor rolipram. In one embodiment, the liposome is an anionic liposome. In another embodiment, the liposome comprises negatively charged phospholipids and neutrally charged phospholipids. In a further embodiment, a molar ratio of the neutrally charged phospholipids to the negatively charged phospholipids is between 5:1 and 1:1. In some embodiments, the negatively charged phospholipids are phosphatidic acid (PA). In some embodiments, the neutrally charged phospholipids are phosphatidylcholine (PC). In certain embodiments, the liposome comprises 1,2-Dioleoyl-sn-glycerol-3-phosphocholine (DOPC) and 1-palmitoyl-2-oleol-sn-glycerol-3-phosphate (POPA). Additionally or alternatively, in some embodiments, the composition further comprises an excipient. In one embodiment, the excipient is sucrose octaacetate.
Also provided herein, in some embodiments, is a composition for treating liver inflammation, the composition comprising a phosphodiesterase 4 (PDE4) inhibitor and a liposome, the liposome encapsulating the PDE4 inhibitor. In one embodiment, the liposome comprises negatively charged phospholipids and neutrally charged phospholipids. In another embodiment, the liposome is an anionic liposome. In a further embodiment, a molar ratio of the neutrally charged phospholipids to the negatively charged phospholipids is between 5:1 and 1:1. In some embodiments, the negatively charged phospholipids are phosphatidic acid (PA). In some embodiments, the neutrally charged phospholipids are phosphatidylcholine (PC). In certain embodiments, the liposome comprises 1,2-Dioleoyl-sn-glycerol-3-phosphocholine (DOPC) and 1-palmitoyl-2-oleol-sn-glycerol-3-phosphate (POPA).
In some embodiments, the PDE4 inhibitor is a biologically active analogue of rolipram. In some embodiments, the PDE4 inhibitor is selected from the group consisting of rolipram, apremilast, crisaborole, roflumilast, cilomilast, piclamilast, ibudilast, and lirimilast. In some embodiments, the composition further comprises an excipient. In one embodiment, the excipient is sucrose octaacetate.
The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are used, and the accompanying drawings of which:
The details of one or more embodiments of the presently-disclosed subject matter are set forth in this document. Modifications to embodiments described in this document, and other embodiments, will be evident to those of ordinary skill in the art after a study of the information provided in this document. The information provided in this document, and particularly the specific details of the described exemplary embodiments, is provided primarily for clearness of understanding and no unnecessary limitations are to be understood therefrom. In case of conflict, the specification of this document, including definitions, will control.
While the terms used herein are believed to be well understood by those of ordinary skill in the art, certain definitions are set forth to facilitate explanation of the presently-disclosed subject matter. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which the invention(s) belong.
Where reference is made to a URL or other such identifier or address, it understood that such identifiers can change and particular information on the internet can come and go, but equivalent information can be found by searching the internet. Reference thereto evidences the availability and public dissemination of such information.
As used herein, the abbreviations for any protective groups, amino acids and other compounds, are, unless indicated otherwise, in accord with their common usage, recognized abbreviations, or the IUPAC-IUB Commission on Biochemical Nomenclature (see, Biochem. (1972) 11(9):1726-1732).
Although any methods, devices, and materials similar or equivalent to those described herein can be used in the practice or testing of the presently-disclosed subject matter, representative methods, devices, and materials are described herein.
Following long-standing patent law convention, the terms “a”, “an”, and “the” refer to “one or more” when used in this application, including the claims.
Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about”. Accordingly, unless indicated to the contrary, the numerical parameters set forth in this specification and claims are approximations that can vary depending upon the desired properties sought to be obtained by the presently-disclosed subject matter.
As used herein, the term “about,” when referring to a value or to an amount of mass, weight, time, volume, concentration or percentage is meant to encompass variations of in some embodiments ±20%, in some embodiments ±10%, in some embodiments ±5%, in some embodiments ±1%, in some embodiments ±0.5%, and in some embodiments ±0.1% from the specified amount, as such variations are appropriate to perform the disclosed method.
As used herein, ranges can be expressed as from “about” one particular value, and/or to “about” another particular value. It is also understood that there are a number of values disclosed herein, and that each value is also herein disclosed as “about” that particular value in addition to the value itself. For example, if the value “10” is disclosed, then “about 10” is also disclosed. It is also understood that each unit between two particular units are also disclosed. For example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are also disclosed.
The presently-disclosed subject matter includes products for encapsulation and/or delivery of one or more phosphodiesterase (PDE) inhibitors. In some embodiments, the products include lipid vesicles, such as fusogenic lipid vesicles (FLVs) and/or nanoliposomes (NLs), arranged and disposed for entrapment and/or encapsulation of one or more PDE inhibitors. In some embodiments, the lipid vesicles are arranged and disposed to target the PDE inhibitors to the liver and/or decrease or eliminate access of the PDE inhibitors to the central nervous system (CNS). For example, in one embodiment, the lipid vesicles target the PDE inhibitor(s) to the liver while limiting PDE access to the CNS. In another embodiment, the lipid vesicles facilitate and/or provide reduced PDE activity in the liver but not in the brain. In a further embodiment, the lipid vesicles decrease or eliminate CNS side effects of PDE inhibitors as compared PDE inhibitors alone.
In contrast to other drug-carrying liposomes that are designed and formulated to reduce uptake by the reticuloendothelial system (RES), which prolongs circulation time and the biological half-life of the drugs, the lipid vesicles described herein are arranged and disposed to fuse with cells and increase uptake by the RES (e.g., Kupffer cells), which shortens circulation time of the lipid vesicle-PDE inhibitor complex. Without wishing to be bound by theory, it is believed that the increased uptake of the lipid vesicle-PDE inhibitor complex by the RES decreases or eliminates free systemic circulation of the PDE inhibitor, which prevents or substantially prevents the PDE inhibitor from crossing the blood-brain barrier and reaching the brain. This decreases or eliminates the side effects induced by PDE inhibitors in the brain, such as severe nausea and emesis, thereby permitting and/or facilitating the use of PDE inhibitors in disease therapy.
The biodistribution of the lipid vesicles is determined, at least in part, by the lipid composition, charge, and/or vesicle size thereof. For example, in some embodiments, the lipid vesicles include a lipid composition configured to increase vesicle-to-cell fusion rates. In one embodiment, a charge of the phospholipid head group may be manipulated to create dissimilar regions in the lipid layer. In another embodiment, the lipid composition provides the lipid vesicle with an overall negative charge. In a further embodiment, the overall negative charge of the lipid vesicles facilitates and/or promotes vesicle-to-cell fusion. Additionally or alternatively, the overall negative charge of the lipid vesicle prevents or substantially prevents the vesicles from fusing with each other. These properties reduce or eliminate lipid vesicle fusion while transiting in circulating blood (i.e., unwanted lipid vesicle fusion), which reduces or eliminates systemic drug release from such unwanted fusion.
In certain embodiments, the lipid composition includes at least one neutrally charged phospholipid and at least one negatively charged phospholipid, at physiological pH. In one embodiment, the neutrally charged phospholipids include, but are not limited to, phosphocholines (PCs). In another embodiment, the negatively charged phospholipids include, but are not limited to, phosphatidic acids (PAs).
Suitable PCs include, but are not limited to, saturated PCs, such as 12:0 PC 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC), 14:0 PC 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), 16:0 PC 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 18:1 (Δ9-Cis) PC 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), 20:1 (Δ11-Cis) PC 1,2-dieicosenoyl-sn-glycero-3-phosphocholine, or a combination thereof.
Suitable PAs include, but are not limited to, 16:0-18:1 PA 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphate (POPA) (sodium salt), 12:0 PA 1,2-dilauroyl-sn-glycero-3-phosphate (DLPA) (sodium salt), 14:0 PA 1,2-dimyristoyl-sn-glycero-3-phosphate (DMPA) (sodium salt), or a combination thereof.
The at least one neutrally charged phospholipid and the at least one negatively charged phospholipid are combined at any suitable mole ratio to provide the desired fusion rate and/or overall charge of the lipid vesicle. In some embodiments, the mole ratio of neutrally charged phospholipids to negatively charged phospholipids is between about 5:1 and about 1:1. For example, in one preferred embodiment, the lipid composition of an anionic lipid vesicle includes DOPC:POPA at a 3:2 mole ratio. In another preferred embodiment, the lipid composition of an anionic lipid vesicle includes DPPC:POPA at a 3:2 mole ratio. In certain embodiments, the mole ratio of neutrally charged phospholipids to negatively charged phospholipids provides an overall negative charge that prevents the lipid vesicles from fusing together and/or facilitates vesicle-to-cell fusion in the liver. By preventing lipid vesicle fusion, particularly while transiting in circulating blood, the neutral to negatively charged phospholipid mole ratio also reduces or eliminates unwanted systemic drug release.
In some embodiments, the lipid vesicles include a diameter of up to 150 nm, between 50 nm and 150 nm, between 70 nm and 150 nm, or any combination, sub-combination, range, or sub-range thereof. More specifically, in one embodiment, the lipid vesicles include a diameter of between 50 nm and 150 nm. In another embodiment, having a formulation according to one or more of the embodiments disclosed herein and a diameter of between 50 nm and 150 nm prevents or substantially prevents the lipid vesicle from crossing the blood-brain-barrier. In a further embodiment, when administered to a subject, this combination of formulation, charge, and size targets the lipid vesicles to the liver cells while preventing or substantially preventing entrapment of the lipid vesicle in lungs and/or organs other than the liver.
The PDE inhibitor includes any PDE inhibitor suitable for encapsulation by the lipid vesicle and/or targeted PDE inhibition in the liver. In some embodiments, the PDE inhibitors are lipophilic. Additionally or alternatively, in some embodiments, the PDE inhibitors are selective inhibitors. For example, in one embodiment, the PDE inhibitor includes one or more PDE 4 inhibitors, such as, but not limited to, rolipram, apremilast, crisaborole, roflumilast, cilomilast, piclamilast, ibudilast, and/or lirimilast. In another embodiment, the PDE inhibitor includes rolipram, a selective PDE-4 inhibitor also known as 4-(3-Cyclopentyloxy-4-methoxy-phenyl) pyrrolidin-2-one, which has the structure shown below:
In some embodiments, the lipophilic properties of the PDE inhibitor, such as rolipram, which has a log P value of 2.51, permit and/or facilitate incorporation thereof into a membrane-compartment of the lipid vesicle. The incorporation of the rolipram or other lipophilic PDE inhibitor into the membrane-compartment of the lipid vesicle provides increased and/or longer retention as the lipid vesicles circulate in the blood. Increased and/or longer retention of the PDE inhibitors decreases or eliminates free systemic circulation thereof, which decreases or eliminates crossing of the blood-brain-barrier and/or the negative side effects previously associated with PDE inhibitors.
In certain embodiments, a lipid to drug ratio is selected to provide desired, increased, and/or maximal encapsulation efficiency of effective PDE inhibitor levels. For example, in one embodiment, the lipid to rolipram ratio is between about 10:1 and about 30:1 mg of lipid per mL of buffer. In another embodiment, the encapsulation efficiency of the drug in the lipid vesicle is at least 50%, at least 60%, at least 70%, at least 75%, at least 80%, or any combination, sub-combination, range, or sub-range thereof. As will be appreciated by those skilled in the art, the lipid to drug ratio and/or encapsulation efficiency may vary depending upon the specific combination of lipids and PDE inhibitors, and is not limited to the ranges provided above.
The presently-disclosed subject matter also includes a complex for PDE inhibitor delivery. The complex includes one or more of the PDE inhibitors discussed above encapsulated and/or entrapped in one or more of the lipid vesicles discussed above. In some embodiments, the complex also includes one or more excipients. In one embodiment, the one or more excipients include an excipient-emulgent. In another embodiment, the one or more excipients stabilize the PDE inhibitor within the aqueous compartment of the lipid vesicle. In a further embodiment, the one or more excipients extend a shelf-life of the lipid vesicle-PDE inhibitor complex and/or increase water solubility of the PDE inhibitor within the lipid vesicle, which may increase a concentration of PDE inhibitor entrapped in the lipid vesicles and/or the amount of PDE inhibitor delivered to the liver. Suitable excipients include, but are not limited to, sucrose octaacetate (SOA), sucrose acetate isobutyrate (SAIB), polysorbate 80, polyoxyl-15-hydroxystearate, cyclodextrins (HP-CD and SBE-CD), γ-cyclodextrin, hydroxypropyl-γ-cyclodextrin, or a combination thereof. For example, the excipient may include sucrose octaacetate (SOA) added to the buffer in the aqueous compartment to increase rolipram solubility and stability.
The presently-disclosed subject matter further includes methods involving administering one or more phosphodiesterase (PDE) inhibitors to a subject in need thereof. In some embodiments, a method of treating a disease includes administering to a subject in need thereof a therapeutically effective amount of PDE inhibitor encapsulated in a carrier system. In some embodiments, a method of reducing side effects of one or more PDE inhibitors includes administering to a subject in need thereof a therapeutically effective amount of PDE inhibitor encapsulated in a carrier system. The PDE inhibitor includes any suitable PDE inhibitor disclosed herein. For example, in one embodiment, the PDE inhibitor includes a PDE4 inhibitor and/or a biologically active analogue thereof. In another embodiment, the PDE4 inhibitor includes rolipram and/or a biologically active analogue thereof. In a further embodiment, the carrier system includes one or more of the lipid vesicles disclosed herein. The PDE inhibitor encapsulated in the carrier system may be administered to the subject by any suitable method of administration, including, but not limited to, intravenous administration (IV).
In some embodiments, in contrast to existing liposomal drug delivery systems that prolong vesicle circulation time to increase the duration of therapeutic effect, the carrier system disclosed herein is arranged and disposed to deliver and/or target the PDE inhibitor to the subject's liver. Delivering and/or targeting the PDE inhibitor to the subject's liver provides and/or facilitates rapid sequestration of the PDE inhibitor by the liver, which reduces the duration and amount of PDE inhibitor that circulates systemically. In one embodiment, after reaching the liver, the encapsulated PDE inhibitor remains therein where it exerts its therapeutic effect. In another embodiment, encapsulation of the PDE inhibitor in the carrier system and/or targeting of the PDE inhibitor to the subject's liver prevents or substantially prevents the PDE inhibitor from crossing the blood-brain-barrier. In a further embodiment, preventing or substantially preventing the PDE inhibitor from crossing the blood-brain-barrier decreases or eliminates adverse side effects of PDE inhibitors, such as, but not limited to, emesis, nausea, or a combination thereof.
By decreasing or eliminating the adverse side effects of PDE inhibitors, the methods disclosed herein provide and/or facilitate administration of one or more PDE inhibitors for treatment of diseases such as, but not limited to, liver inflammation, alcoholic liver disease, alcoholic hepatitis with or without superimposed cirrhosis, non-alcoholic steatohepatitis (NASH), or a combination thereof. For example, the instant inventors have studied the pathogenic role of PDE4 in regulating hepatic TNF production, hepatic inflammation, and liver injury, and demonstrated a significant up regulation of hepatic PDE4 expression caused by alcohol feeding in mice. The instant inventors have also observed that cyclic AMP (cAMP) decreases when isolated cells are exposed to alcohol, and is associated with an increase in pro-inflammatory cytokine levels. Experiments in which cellular cAMP concentrations were increased attenuated this increase in proinflammatory cytokines. Furthermore, the instant inventors have observed an increase in PDE4B in the decreased cAMP concentrations in alcohol-exposed cells. In view thereof, without wishing to be bound by theory, it is believed that altered PDE4B and cAMP metabolism cause abnormal cytokine (e.g., TNF and IL-10) production/activity, which play a critical role in the development and perpetuation of diseases such as ALD. Accordingly, as the instant inventors have demonstrated that PDE inhibitor-mediated inhibition of PDE4 significantly down-regulates LPS-inducible TNF, targeted delivery of PDE inhibitors (e.g., rolipram a PDE 4B inhibitor) to the liver provides correction of dysregulated cytokine production to treat one or more of the diseases disclosed above without the side effects resulting from PDE inhibitors crossing the blood-brain-barrier and entering the CNS.
The presently-disclosed subject matter is further illustrated by the following specific but non-limiting examples. The following examples may include compilations of data that are representative of data gathered at various times during the course of development and experimentation related to the presently-disclosed subject matter.
The following examples describe the development of lipid vesicle carriers that target PDE inhibitors to the Kupffer cells in the liver while limiting drug access to the CNS to reduce or eliminate side effects of the drug. More specifically, the instant inventors encapsulated PDE inhibitors in NLs or FLVs that are specifically sized and formulated to target Kupffer cells in the liver. To enhance the PDE inhibitor entrapment efficiency of nanoliposomes (NLs) and targeting of the therapy to the liver, three important factors were considered: 1) specific lipid formulation, vesicle size, and charge (−) were determined to target the NL-PDE inhibitor to liver Kupffer cells; 2) an optimal lipid to drug ratio was determined to achieve maximal encapsulation efficiency of effective PDE inhibitor levels; and 3) an amount of the excipient added to the buffer in the aqueous compartment was determined to increase PDE inhibitor solubility and stability.
Studies in monocytes have shown that cAMP plays an important role in regulating TNF expression, and that the elevation of cellular cAMP suppresses TNF production. Therefore, the instant inventors evaluated (1) the effects of chronic ethanol exposure on the cellular levels of cAMP, and (2) TNF expression in monocytes in vitro and in rat primary hepatic Kupffer cells obtained from a clinically relevant enteral alcohol feeding model of alcoholic liver disease (ALD). The results indicated that chronic ethanol exposure significantly decreased cellular cAMP levels in both LPS-stimulated and un-stimulated monocytes (both in mouse macrophages—RAW 264.7 and Kupffer cells from rats that were chronically and intragastrically fed alcohol) (
The effect of chronic ethanol exposure on PDE4 gene expression and activity in human THP-1 and mouse RAW macrophages was evaluated next, as a mechanism for the decreased intracellular cAMP levels and the increased LPS-stimulated TNF.4 PDE4 (predominantly present in monocytes) degrades and inactivates cAMP, with PDE4B playing a critical role in LPS signaling. It was shown that chronic alcohol increased LPS-inducible PDE4B mRNA expression (
To evaluate the ability of the FLVs to retain rolipram in an aqueous system, 0.75 mg/mL of rolipram was loaded into the lipid bilayer and internal liquid compartment of FLVs using four concentrations of lipid: 5, 10, 12.5, and 15 mg/ml. The rolipram encapsulation efficiency was quantified. Results showed that the initial encapsulation efficiency of rolipram increased as the amount of lipid increased up to about 80% (
To evaluate the effect of dilution on encapsulation efficiency of FLVs-rolipram, different concentrations of FLV lipid (10, 12.5 and 15 mg/ML) were hydrated with the same amount of rolipram (0.75 mg/mL) and then diluted in water 5 and 10 times. Rolipram levels in the external buffer compartment were measured over a 90 min period. The results showed that after dilution in a closed system FLVs released rolipram over time but levels in buffer never were less than 50% of the total drug used (
Water-soluble non-polar excipients sucrose octaacetate (SOA) and sucrose acetate isobutyrate (SAIB) were added to the aqueous compartment of NLs or FLVs to stabilize rolipram in the vesicle's aqueous compartment. SOA and SAIB are emulgents that decrease the interaction of molecules in solution. SOA and SAIB did not significantly alter the rolipram encapsulation efficiency (
The effect of adding SAIB (0.5 mg/mL) to the vehicle was tested in vitro using RAW cells pulsed with LPS (100 ng/mL) and evaluated for TNF production. Rolipram (0.75 mg/mL) encapsulated in of 10 mg/mL of lipid without SAIB was used as a control. SAIB reduced the effect of LPS, and also, FLVs (10 mg/mL) with SAIB without rolipram further reduced TNF production after LPS exposure (
Studies quantifying the fusion rate of vesicles loaded with rolipram to RAW or mouse aortic endothelial cells (MAECs) were performed. In the first experiment, the fusion rate of lipid vesicles to RAW cells using a highly fusogenic vesicle formulated with DOPC/POPA was compared to less fusogenic vesicle formulated with DOPC (
To document the major uptake of FLVs by the liver but not CNS, FLVs were labeled with DiR (a lipophilic near-infrared dye) and infused i.v. into nude mice. The FLVs were tracked in vivo for 96 hours using a Kodak Image Station 4000.
An in silico analysis of the potential toxicity of lipids used in the instant FLV formulation was performed by Dr. A. R. Cunningham, the developer of the software for the cat-structure-activity relationship (cat-SAR). The cat-SAR program estimates the toxicological properties of chemicals, based on information from previously tested compounds. The method has been described in detail in several peer-reviewed publications.30-32 The models are built for specific toxicological endpoints (e.g., carcinogenicity or genotoxicity) and describe the chemical substructures that differentiate between active and inactive chemicals for the endpoint of interests (e.g., carcinogens and non-carcinogens).
Table 1 lists the predicted toxicity values for each lipid as a probability of activity of all possible metabolites. The Cut-Off point values correspond to the Validation Results and are used to separate the probability of activity values to “positive” and “negative” calls. The first value is from a model with equal sensitivity and specificity and the second value is from a model with the best overall concordance between experimental and predicted results. In order to assess the toxicological potential of the FLV lipids DOPC and POPA, the cat-SAR models were adjusted for a balance between sensitivity and specificity. The results showed that DOPC and POPA were inactive for Salmonella mutagenicity, carcinogenic potency for rat cancer, human developmental toxicity, MCF-7 Relative Proliferate Effect (ESCREEN), and FDA National Center for Toxicological Research Estrogen Receptor Binding (NCTER ER). However, DOPC and POPA were positive for mouse cancer; however, according to Dr. Cunningham, a positive mouse cancer finding is muted in the setting of negative findings for rat cancer and Salmonella mutagenicity. The rationale is that a negative prediction of mutagenicity in the Salmonella model goes against the notion of a metabolite being a mutagenic carcinogen.
Salmonella, NTP
Examples 7-9 were aimed at developing a novel fusogenic lipid vesicle (FLV) delivery system that specifically targeted effective levels of rolipram to the liver, while limiting access to the CNS and side effects. The experiments focused on determining an optimal low-dose of 1st generation FLVs-rolipram complexes to inhibit LPS-induced cytokine expression in the liver, without affecting brain PDE4 activity.
The initial experiments were performed in rats, in five distinct groups (n=10 per group): (1) a sham group receiving an injection of PBS; (2) a group receiving an injection of empty FLVs intra-peritoneal (i.p.); (3) a group receiving an injection of LPS (i.p. 1 mg/kg body weight (bw)); and three groups receiving injections of first generation FLVs containing either 1, 2 or 3.3 mg/kg bw of Rolipram. FLV-rolipram was administered 4 h before LPS injection. Six hours after LPS injection, blood samples were collected, the animals were euthanized, and the liver and brain were harvested. Serum cytokine levels were measured by ELISA kits and tissue TNF mRNA levels were assessed by real time PCR.
The data showed that serum TNF levels were decreased by all doses of FLVs-rolipram. However, monocyte chemoattractant protein 1 (MCP-1) levels were not affected. Hepatic TNF mRNA levels were not decreased by 1 and 2 mg/kg bw Rolipram dose; however the 3.3 mg/kg bw dose significantly attenuated hepatic TNF mRNA (
Additional single dose studies were conducted in C57Bl/6 mice using an improved FLV formulation and a FLVs-rolipram dose of 3.3 mg/kg bw. The goal of these Examples was to determine the longevity of a single dose of FLVs-rolipram in response to an LPS stimulus administered 12 h or 72 h post-therapy. Blood, brain and liver tissues were collected 3 h after LPS. Assessment of liver PDE4 specific enzymatic activity demonstrated that FLVs-rolipram effectively decreased PDE4 activity compared to the LPS control group; this effect was maintained up to 72 h post FLVs-rolipram administration (
To evaluate the longevity of a single FLVs-rolipram injection on LPS-inducible serum cytokines, the Luminex 100 IS system (Luminex Corp., Austin, Tex.) was used. The advantage of the Luminex technology is that it allows the simultaneous measurement of different analytes in a single sample using as little as 25 μl or less. IFN-γ, IL-1β, L-6, IL-10, IL-12p40, MCP-1 and TNF were quantified, and it was observed that mice treated with FLVs-rolipram, 12 h prior to an LPS injection, experienced a significant decrease in serum TNF and MCP-1 levels compared to LPS controls (
An in vitro screening assay to evaluate the effectiveness of the FLVs-rolipram formulations was developed. The assay uses a murine macrophage cell line (RAW 264.7 cells), which produces high levels of TNF in response to LPS stimulation. The cells were plated in a 24-well plate and pre-treated next day with the improved DOPC/POPA formulated FLVs-rolipram, 4 h before LPS stimulation. After 24 h, TNF protein was measured in cell free supernatant by ELISA kit (
A chronic-plus-binge alcohol feeding model of ALD, described by Bin Gao's group,33 was used in Example 9. In this model—in which the mice develop steatosis, liver injury, and inflammation—the mice are fed the Lieber-DeCarli liquid diet containing 5% ethanol for 10 days; on the 11th day, they are given 31.5% (vol/vol) ethanol gavage, which is similar to the drinking pattern in many alcoholic hepatitis patients that have a background of chronic drinking for many years (chronic) and a history of recent excessive alcohol consumption (binge). This model was used to examine the effect of FLVs-rolipram in attenuating liver injury induced by alcohol. C57Bl/6 mice were pair-fed the Lieber-DeCarli liquid diet (Bio-Serv, Frenchtown, N.J.) as described previously. FLVs-rolipram was administered 12 hours before alcohol gavage. The mice were sacrificed 6 h after alcohol gavage. Control mice, on an isocaloric liquid control diet, were gavaged with maltose dextrin instead of alcohol. The mice were divided into six groups: Group 1 included pair-fed (PF)-mice receiving Lieber-DeCarli liquid control diet (no ethanol); Group 2 mice on the control diet were administered FLVs only (PF+FLVs) 12 h before maltose dextrin gavage; Group 3 mice on the control diet were administered FLVs-rolipram (PF+FLV-Rol) 12 h before maltose dextrin gavage; Group 4 mice on Lieber-DeCarli liquid ethanol diet (5% ethanol) for 10 days followed by alcohol gavage (31.5% vol/vol) (AF); Group 5 mice on Lieber-DeCarli liquid ethanol diet were administered FLVs 12 h (AF+FLV) before ethanol gavage; and Group 6 mice on Lieber-DeCarli liquid ethanol diet were administered FLVs-rolipram (AF+FLV-Rol) 12 h before ethanol gavage.
Assays for liver enzymes (ALT, AST), liver caspase 3, TUNEL, CAE, Oil red O staining were performed to document liver injury, steatosis and inflammation. Alcohol induced PDE4 expression changes were assessed by measuring hepatic PDE4 mRNA levels. As expected, ethanol feeding induced a significant upregulation of PDE4B, C and D mRNA levels in the liver (
Neutrophil infiltration into the liver was estimated by means of naphthol AS-D chloroacetate esterase (CAE) staining of liver sections. The resulting images demonstrated that FLVs-rolipram reduced neutrophil infiltration in livers induced by alcohol gavage (
To further evaluate the effect of FLVs-rolipram on alcohol induced liver injury, the Caspase-3 assay was performed on liver lysates using the Caspase-3 kit (Promega Corporation, Madison, Wis.). The data showed that alcohol-gavage resulted in a significant increase in liver caspase-3 activity (
Alcohol consumption causes an increase in gut permeability and endotoxemia which plays a critical role in alcohol mediated liver injury. The effect of FLVs-rolipram on endotoxin levels were evaluated in this model and an increase in endotoxin levels after alcohol-binge was observed (
The effect of FLVs-rolipram on LPS-inducible TNF and IL-10 expression in the liver was tested. Wistar rats were injected (i.p.) with FLVs-rolipram (3.3 mg/kg bw) and 4 hours later administered LPS (1 mg/kg bw). FLVs-rolipram significantly inhibited LPS-inducible TNF mRNA and upregulated IL-10 mRNA in the liver (
Safety pharmacology studies were conducted to determine the dose-response relationship of adverse effects observed by rolipram. The primary side effect of rolipram is the inhibition of PDE4 activity in the CNS, which leads to emesis in humans. The mechanism of the emetic response associated with PDE4 inhibitors is thought to produce a pharmacological response analogous to that of presynaptic α2-adrenoceptor inhibition, by elevating intracellular levels of cAMP in noradrenergic neurons. Consequently, PDE4 inhibitors remove an inhibitory mechanism that modulates the release of mediators (5-HT, substance P, noradrenaline) involved in the onset of the emetic reflex. Without wishing to be bound by theory, it is believed that encapsulating rolipram in fusogenic lipid vesicles (FLVs) will limit the drug from reaching the central nervous system (CNS), and thus, attenuate the emetic side effects. Accordingly, the goal of these dose response studies was to examine the effect of rolipram alone or encapsulated in FLVs on the duration of anesthesia.
Since rodents are a non-vomiting species, examining rolipram-induced side effects in rodents is particularly difficult.34-36 To circumvent this problem, a behavioral correlate of emesis model in mice was utilized.35 In this model, rolipram is used to reverse the duration of α2-adrenoceptor-mediated xylazine/ketamine-induced anesthesia, which is temporally quantified by the return of the righting reflex. More specifically, using a paired design study, male C57BL/6 mice (25-30 g bw; n=6 per group unless indicated otherwise) were anesthetized with a ketamine (80 mg/kg bw) and xylazine (10 mg/kg bw) mixture administered in a single intraperitoneal (i.p.) injection. The anesthesia mixture was freshly prepared for each set of experiments by mixing 4.8 mL of ketamine, 1.5 mL of xylazine, and 13.7 mL of saline. After 15 min, the mice were placed on a controlled heating pad in the dorsal recumbent position and the duration of anesthesia was determined by timing the return of the righting reflex.
Four days later, the same animals were re-anesthetized with the same dose of ketamine/xylazine, placed in the dorsal recumbent position, injected IV with either free rolipram (1.6, 3.3, and 6.6 mg/kg bw) or FLVs-rolipram (1.6, 3.3, and 6.6 mg/kg bw), and the duration of anesthesia was measured again. A PBS solution containing 0.375 mg/mL of rolipram was used to deliver the 1.6 mg/kg bw of rolipram dose. The concentration of rolipram in PBS solution for the 3.3 and 6.6 mg/kg bw doses was 0.75 mg/mL. The FLVs were made of DOPC and POPA at a 3:2 mole ratio and were prepared using sonication and extrusion. FLV size was quantified by nano-tracking analysis (NTA) using a Particle Metrix system. A PBS solution containing 0.75 mg/mL of rolipram and a dose of 55 mg/kg bw of lipid was used to deliver the 1.6 and 3.3 mg/kg bw rolipram doses. The lipid dose was increased to 110 mg/kg bw for the 6.6 mg/kg rolipram dose.
As illustrated in
The results of these studies showed that encapsulating rolipram in FLVs prevented a significant shortening of the anesthesia duration for low, target and high doses tested. Accordingly, these results suggest that the side effects caused by free rolipram crossing the blood-brain-barrier and reaching the CNS are ameliorated by FLV encapsulation.
All patents, patent applications, publications, and other published materials mentioned in this specification, unless noted otherwise, are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference, including the references set forth in the following list:
It will be understood that various details of the presently disclosed subject matter can be changed without departing from the scope of the subject matter disclosed herein. Furthermore, the foregoing description is for the purpose of illustration only, and not for the purpose of limitation.
This application claims the benefit of U.S. Provisional Application Ser. No. 62/419,114, filed Nov. 8, 2016, the entire disclosure of which is incorporated herein by this reference.
This invention was made with government support under grant numbers R43AA021331 and R44AA021331 awarded by the National Institutes of Health (NIH). The government has certain rights in the invention.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2017/060642 | 11/8/2017 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62419114 | Nov 2016 | US |
