摘要:
Bioerodible polymers which degrade completely into nontoxic residues over a clinically useful period of time, including polyanhydrides, polyorthoesters, polyglycolic acid, polylactic acid, and copolymers thereof, are used for the delivery of bioactive agents, including antibiotics, chemotherapeutic agents, inhibitors of angiogenesis, and simulators of bone growth, directly into bone.
摘要:
A bioerodible controlled drug release device is produced as a homogeneous polymeric matrix from a high molecular weight polyanhydride and a suitable biologically active substance. The high molecular weight polyanhydride is defined by a molecular weight greater than 20,000 and an intrinsic viscosity greater than 0.3 dl/g. The controlled drug release device is preferrably formed by solvent casting with the biologically active substance and exhibits zero order release, improved correlation between the rate of release and polymer degradation, and an induction period between introduction to the eroding environment and the initial release of the biologically active substance. The controlled drug release devices are stable for extended periods of time, flexible and durable and not subject to fracture and disintegration.
摘要:
Hydroxamic acid polymers which are comprised of hydroxamic groups and carboxylic acid groups wherein the carboxylic acid groups constitute less than about 3% of the functional groups. The polymers hereof are also especially useful in biomedical applications because, for example, the low concentration of carboxylic acid groups decreases the incidence of bioincompatibility. Additionally, the polymers exhibit anticoagulant activity, urease inhibition activity, metal chelating activity and ion exchange activity.
摘要:
A method for preparing hydroxamic acid polymers from primary amide polymers wherein polyvinyl monomers such as polyacrylamide are reacted with hydroxyl amine in aqueous solution at room temperature. The low reaction temperature is crucial to producing a high yield (70%) of polymer with hydroxamic acid groups and having a low carboxylic acid content (less than 15%, preferably less than 3%). The polymers display high metal affinity over a broad pH range.The polymers are particularly useful for biomedical applications due to the low carboxylic acid content and for the removal and purification of metals due to the high binding constants and rapid reaction rates.
摘要:
A class of unsaturated polyanhydrides having double bonds available for secondary polymerization is disclosed. A crosslinked material having improved or different physical and mechanical properties can be prepared from these polyanhydrides, via secondary polymerization. The synthesis and characteristics of one unsaturated polyanhydride based on fumaric acid and its copolymers with aliphatic and aromatic diacids, prepared by either the melt-polycondensation method or by solution polymerization, is described in detail.These polymers are well suited for use in controlled release drug delivery devices. The polymers can also be used as a bioerodible bone cement where the polymer is first cast as a solution onto a bone fracture and then crosslinked by radiation or radical polymerization to yield a strong, adhesive material.
摘要:
A method and devices for localized delivery of a chemotherapeutic agent to solid tumors, wherein the agent does not cross the blood-brain barrier and is characterized by poor bioavailability and/or short half-lives in vivo, are described. The devices consist of reservoirs which release drug over an extended time period while at the same time preserving the bioactivity and bioavailability of the agent. In the most preferred embodiment, the device consists of biodegradable polymeric matrixes, although reservoirs can also be formulated from non-biodegradable polymers or reservoirs connected to implanted infusion pumps. The devices are implanted within or immediately adjacent the tumors to be treated or the site where they have been surgically removed. The examples demonstrate the efficacy of paclitaxel and camptothecin delivered in polymeric implants prepared by compression molding of biodegradable and non-biodegradable polymers, respectively. The results are highly statistically significant.
摘要:
Injectable particles are provided that are not rapidly cleared from the blood stream by the macrophages of the reticuloendothelial system, and that can be modified as necessary to achieve variable release rates or to target specific cells or organs as desired. The injectable particles can include magnetic particles or radiopaque materials for diagnostic imaging, biologically active molecules to be delivered to a site, or compounds for targeting the particles. Biodistribution experiments indicate that the injectable particles have a prolonged half-life in the blood compared to particles not containing poly(alkylene glycol) moieties on the surface.
摘要:
A method and devices for localized delivery of a chemotherapeutic agent to solid tumors, wherein the agent does not cross the blood-brain barrier and is characterized by poor bioavailability and/or short half-lives in vivo, are described. The devices consist of reservoirs which release drug over an extended period while at the same time preserving the bioactivity and bioavailability of the agent. In the most preferred embodiment, the device consists of biodegradable polymeric matrixes, although reservoirs can also be formulated from non-biodegradable polymers or reservoirs connected to implanted infusion pumps. The devices are implanted within or immediately adjacent the tumors to be treated or the site where they have been surgically removed.
摘要:
A method and devices for localized delivery of a chemotherapeutic agent to solid tumors, wherein the agent does not cross the blood-brain barrier and is characterized by poor bioavailability and/or short half-lives in vivo, are described. The devices consist of reservoirs which release drug over an extended time period while at the same time preserving the bioactivity and bioavailability of the agent. In the most preferred embodiment, the device consists of biodegradable polymeric matrixes, although reservoirs can also be formulated from non-biodegradable polymers or reservoirs connected to implanted infusion pumps. The devices are implanted within or immediately adjacent the tumors to be treated or the site where they have been surgically removed. The examples demonstrate the efficacy of paclitaxel and camptothecin delivered in polymeric implants prepared by compression molding of biodegradable and non-biodegradable polymers, respectively. The results are highly statistically significant.
摘要:
A method for synthesizing polyanhydrides in solution using coupling agents and a removable acid acceptor to effect a one-step polymerization of dicarboxylic acids. As used in the method, these coupling agents include phosgene, diphosgene, and acid chlorides. Insoluble acid acceptors include insoluble polyamines and crosslinked polyamines such as polyethyleneimine and polyvinylpyridine and inorganic bases such as K.sub.2 CO.sub.3, Na.sub.2 CO.sub.3, NaHCO.sub.3, and CaCO.sub.3. The only byproduct formed is a removable hydrochloric acid-acid acceptor.Examples are provided of the polymerization of highly pure polyanhydrides using phosgene, diphosgene or an acid chloride as the coupling agent, in combination with either an insoluble acid acceptor or a soluble acid acceptor in a solvent wherein the polymerization byproduct or polymer is insoluble.A particularly important application of these polyanhydrides is in the formation of drug delivery devices containing bioactive compounds. The method is also useful in the polymerization of dicarboxylic acids including heat liable dipeptides of glutamic or aspartic acid.
摘要翻译:使用偶联剂和可除去的酸受体在溶液中合成聚酐以进行二羧酸的一步聚合的方法。 如该方法所用,这些偶联剂包括光气,双光气和酰氯。 不溶性酸受体包括不溶性多胺和交联聚胺如聚乙烯亚胺和聚乙烯吡啶以及无机碱如K 2 CO 3,Na 2 CO 3,NaHCO 3和CaCO 3。 形成的唯一副产物是可除去的盐酸酸受体。 提供了使用光气,双极光或酰氯作为偶联剂的高纯度聚酐与在溶剂中的不溶性酸受体或可溶性酸受体组合的聚合反应,其中聚合副产物或聚合物是不溶的。 这些多酸酐的特别重要的应用是形成含有生物活性化合物的药物递送装置。 该方法也可用于二羧酸的聚合,包括谷氨酸或天冬氨酸的热应答二肽。