可生物降解交联聚合物的研究进展

交联聚合物具有稳定的三维网络结构,可以提高药物缓释载体的尺寸稳定性。本文综述了可生物降解交联聚合物的研究进展,主要介绍了可生物降解交联聚合物的制备方法,包括交联剂交联、辐照交联、光致交联以及过氧化物交联在制备可生物降解交联聚合物中的应用,详细介绍了交联剂的种类及结构对交联效果的影响、交联后聚合物性能的变化等。最后总结了可生物降解交联聚合物在组织工程支架、药物缓释材料、神经再生修复材料以及形状记忆材料等生物医用领域的应用。     

生物可降解电活性苯胺聚合物

导电聚合物通过其独特的电活性或导电性,可智能地传递或控制细胞电化学信号,从而定向诱导组织器官的再生修复,已成为神经和组织工程领域研究的热点.本文主要介绍了我们实验室生物可降解电活性苯胺聚合物的相关工作,介绍了以苯胺齐聚物与可降解高分子接枝或嵌段制备具有电活性、可生物降解的新型导电聚合物及其在细胞培养和组织工程方面的研究.介绍了静电纺丝制备电活性纳米纤维的概况.苯胺齐聚物与可降解聚合物的接枝和嵌段可同时赋予其电活性、生物相容性和生物可降解性.可生物降解的电活性聚合物是未来生物组织工程领域的发展趋势之一,具有广阔的应用前景.     

聚(丙烯酸钠-4-乙烯基吡啶)的生物降解性和功能性研究

用自由基共聚法制备了一系列可生物降解的功能聚合物聚(丙烯酸钠-4-乙烯基吡啶)[P(SA-co-4VP)],研究了其组成和分子量与生物降解性、资合性及分散性间的关系.结果表明:聚合物中小乙烯基吡啶含量越大,P(SA-co-4VP)的生物降解越显著.分子是一定时,少量的个乙烯基吡啶引入聚丙烯酸钠主链是增强聚合物生物降解性和保持原有功能特性的有效途径.     

可生物降解抗污材料

研究和开发抗生物污染材料,降低蛋白质的非特异性吸附和微生物的附着生长,不仅可以大大提高仪器的灵敏度,降低植入材料在愈合过程中的副作用,如炎症和血栓等,还可以节省很多航海时所需的能源和动力。目前抗污染材料多为亲水性的聚乙烯醇、聚(N-乙烯基吡咯烷酮)、聚(2-口恶唑啉)、聚乙二醇和两性离子聚合物。虽然这些材料抗污染能力强,但是分子链大多为聚丙烯酸酯或聚丙烯酰胺,不具有可生物降解性。可生物降解抗污材料可通过将抗污功能分子引入到可生物降解的基质分子(如脂肪族聚酯、聚碳酸酯、聚多肽和多糖等)中得到。本文综述了可生物降解抗污材料的研究进展,首先介绍了生物污染的危害,抗生物污染材料的分类、特征和存在的问题。重点综述了可生物降解抗污材料的研究现状,从亲水性聚合物(如聚乙二醇、两性离子聚合物)和抗污剂具体阐述了可降解抗污材料的抗污机理、合成、结构和性能,并对可生物降解抗污材料的未来发展进行了展望。     

聚琥珀酸丁二酯的辐射交联和它的热变形行为

近年来 ,塑料废弃物污染环境的问题日趋严重 .对于环境的关心 ,已经使越来越多的科研人员对于研究环境友好化合物的发展产生了极大的兴趣 .发达国家先后制订了限制或禁止某些场合使用非降解性塑料 ,因此 ,多种可生物降解性塑料已经发展起来 .目前已经商业化的可生物降解性聚合物主要有脂肪族聚酯、聚醚、聚乙烯醇和聚多糖 .其中 ,利用化学合成法开发的可生物降解性聚合物是非常重要的 .脂肪族聚酯 ,例如聚乳酸(ＰＬＡ) .聚乙二酸 (ＰＧＡ)等被广泛地用于药物的载体[1] ,聚 (ε 己内酯 ) (ＰＣＬ)也已经被用作生产生物降解性薄膜 .脂肪族聚酯…     

光聚合水凝胶及其在组织工程中的应用

水凝胶是一种亲水性聚合物网络,可以溶胀大量水,其物理性质接近软组织.光聚合与传统的聚合方法相比,具有反应速率快、反应条件缓和、反应放热低等特点.因此,光聚合水凝胶广泛应用于生物医学领域.本文介绍了光聚合水凝胶材料,并详细论述了光聚合水凝胶在药物释放体系、组织工程支架材料、细胞受控生长、细胞微囊化和可注射水凝胶等方面的应用.可以预见光聚合水凝胶作为生物材料在组织工程及再生医学领域中具有良好的应用前景.     

新型官能团化聚己内酯的研究进展

聚己内酯(PCL)是一种具有良好药物透过性的可生物降解的脂肪族聚酯,是一类优良的药物载体.由于其结晶性强,亲水性差,生物降解速度慢,限制了其在组织工程等生物医用领域更广泛的临床应用.在PCL主链上引入功能性官能团既可有效地降低其结晶性、改善其亲水性、调控其降解速率,同时又可通过反应性官能团进行进一步的化学改性或生物活性化修饰,已成为生物可降解材料新的研究热点.本文综述了含侧基官能团己内酯单体的合成及其聚合反应,简要介绍了侧基官能团对聚己内酯性能的影响.     

官能团化聚己内酯的制备及其生物应用

聚己内酯(PCL)是一种疏水的、半结晶的、可降解的脂肪族聚合物,其具有良好的生物相容性、药物透过性和机械性能,在药物缓释和组织工程领域得到了广泛的关注。由于其结晶性强,亲水性差,生物降解速度慢,限制了其在生物医用领域更广泛的应用。聚己内酯的官能团化可实现对聚酯材料亲疏水性、降解速率等物化性质的调节,同时,活性官能团的引入便于对PCL的进一步化学修饰,有利于拓宽聚己内酯类材料的生物医用领域。本文详细介绍在聚己内酯骨架引入侧基官能团的化学方法,并简要阐述了官能团化聚己内酯在生物医用材料领域的应用。     

末端为磷酰胆碱基团的聚丁二酸丁二醇酯的酶促降解和热性能

以聚丁二酸丁二醇酯(PBS)为参照, 研究了酯酶Lipase AY30对亲水磷酰胆碱(PC)基团改性的聚丁二酸丁二醇酯(PBS-PC)的生物降解性能的影响. 结果显示, 在酯酶Lipase AY30作用下, 21 d后PBS的质量损失仅为1.9%, 而PBS-PC的质量损失了9.7%. 相同条件下扣除各自水解引起的质量损失(PBS 1.4%和PBS-PC 6.5%)后, PC亲水基团的引入对聚合物的降解起到了促进作用. 示差扫描量热(DSC)研究结果表明, 改性后的聚合物熔融温度和熔融焓降低, 玻璃化转变温度升高, 表明PC端基的引入降低了PBS的结晶能力, 非晶相结构的增多对聚合物降解有促进作用. 因此PBS-PC有望作为一种新的具有良好生物降解性和生物相容性的高分子材料, 应用于药物控释、基因治疗及组织工程等生物医用材料领域.     

含巯基/二硫键聚合物生物材料

含巯基/二硫键聚合物生物材料具有多种良好的性能,作为药物、基因等的释放载体在生物医学领域具有广泛的应用前景。随着基因工程和组织工程的发展,含巯基/二硫键聚合物生物材料的可生物降解性得到高度重视,而怎样改善其降解性能成为限制其应用的关键因素。由于二硫键在细胞外环境里保持稳定,在细胞溶质的还原环境中容易发生断裂,因此在制备新型基因、药物等释放载体上,二硫键充当了重要的角色,它的引入为聚合物生物材料的生物降解性能的设计与改善提供了一条重要的途径。本综述重点以聚合物水凝胶、聚合物微胶束、囊泡等为例,从巯基/烯的光聚合反应、Michael加成反应、氧化还原反应的角度,介绍了巯基/烯在聚合物中形成二硫键的不同途径的研究进展,并详细论述了基因载体、蛋白质载体、小分子药物载体三种还原敏感型材料的制备、表面修饰和改性的进展情况,进一步强调含巯基/二硫键聚合物生物材料的研究在生物医学领域应用的重要性。     

Effects of an avidin-biotin binding system on chondrocyte adhesion and growth on biodegradable polymers

Cell adhesion to a scaffold is a prerequisite for tissue engineering. Many studies have been focused on enhancing cell adhesion to synthetic materials that are used for scaffold fabrication. In this study, we applied an avidin-biotin binding system to enhance chondrocyte adhesion to biodegradable polymers. Biotin molecules were conjugated to the cell membrane of chondrocytes, and mediated cell adhesion to avidin-coated surfaces. We demonstrated that immobilization of biotin molecules to chondrocyte surfaces enhanced cell adhesion to avidin-coated biodegradable polymers such as poly(L-lactic acid), poly(D,L-lactic acid), and polycaprolactone, compared to the adhesion of normal chondrocytes to the same type of biodegradable polymer. The biotinylated chondrocytes still maintained their proliferation ability. This study showed the promise of applying the avidin-biotin system in cartilage tissue engineering. [diagram in text].     

Biodegradable polymer matrix nanocomposites for tissue engineering: A review

Nanocomposites have emerged in the last two decades as an efficient strategy to upgrade the structural and functional properties of synthetic polymers. Aliphatic polyesters as polylactide (PLA), poly(glycolides) (PGA), poly(?-caprolactone) (PCL) have attracted wide attention for their biodegradability and biocompatibility in the human body. A logic consequence has been the introduction of organic and inorganic nanofillers into biodegradable polymers to produce nanocomposites based on hydroxyapatite, metal nanoparticles or carbon nanotructures, in order to prepare new biomaterials with enhanced properties. Consequently, the improvement of interfacial adhesion between the polymer and the nanostructures has become the key technique in the nanocomposite process. In this review, different results on the fabrication of nanocomposites based on biodegradable polymers for specific field of tissue engineering are presented. The combination of bioresorbable polymers and nanostructures open new perspectives in the self-assembly of nanomaterials for biomedical applications with tuneable mechanical, thermal and electrical properties.     

Synthetic biodegradable functional polymers for tissue engineering: a brief review

Scaffolds play a crucial role in tissue engineering. Biodegradable polymers with great processing flexibility are the predominant scaffolding materials. Synthetic biodegradable polymers with well-defined structure and without immunological concerns associated with naturally derived polymers are widely used in tissue engineering. The synthetic biodegradable polymers that are widely used in tissue engineering, including polyesters, polyanhydrides, polyphosphazenes, polyurethane, and poly (glycerol sebacate) are summarized in this article. New developments in conducting polymers, photoresponsive polymers, amino-acid-based polymers, enzymatically degradable polymers, and peptide-activated polymers are also discussed. In addition to chemical functionalization, the scaffold designs that mimic the nano and micro features of the extracellular matrix (ECM) are presented as well, and composite and nanocomposite scaffolds are also reviewed.     

Photocrosslinkable polyesters and poly(ester anhydride)s for biomedical applications

Crosslinking is a feasible way to prepare biodegradable polymers with potential in biomedical applications such as controlled release of active agents and tissue engineering. A synthesis route in which functional telechelic aliphatic polyester oligomers are used as precursors for the preparation of crosslinked polyesters and poly(ester anhydride)s is described. Mechanical properties, degradation characteristics and rate, and bioactivity can be modified widely by controlling the chemical composition and architecture of the crosslinkable oligomers. In tissue engineering, photocrosslinking allows to use crosslinkable oligomers in advanced manufacturing techniques like micromolding in capillaries, stereolithography and two-photon polymerization.     

Biodegradable polymer blends and composites: An overview

Biodegradable polymers belong to a family of polymer materials that found applications ranged from medical applications including tissue engineering, wound management, drugs delivery, and orthopedic devices, to packaging and films applications. For broadening their potential applications, biodegradable polymers are modified utilizing several methods such as blending and composites forming, which lead to new materials with unique properties including high performance, low cost, and good processability. This paper reviews the recent information about the morphology of blends consisting of both biodegradable and non-biodegradable polymers and associated mechanical, rheological, and thermal properties of these systems as well as their degradation behavior. In addition, the mechanical performance of composites based on biodegradable polymers is described.     

聚乙醇酸类生物降解高分子

聚乙醇酸类生物降解高分子具有良好的生物相容性,在药物缓释材料、组织工程材料、手术缝合线等医用领域有广泛的应用。文章按聚乙醇酸类生物降解高分子的种类不同,介绍了它们的合成、性能与应用,尤其是乙醇酸-乳酸共聚物的研究进展。展望聚乙醇酸类生物降解高分子的未来,降低合成成本是广泛应用的关键,因此简单易行的、以乙醇酸等单体为原料的直接缩聚法合成值得关注。     

Fibers and 3D mesh scaffolds from biodegradable starch-based blends: production and characterization

The aim of this work is the production of fibers from biodegradable polymers to obtain 3D scaffolds for tissue engineering of hard tissues. The scaffolds required for this highly demanding application need to have, as well as the biological and mechanical characteristics, a high degree of porosity with suitable dimensions for cell seeding and proliferation. Furthermore, the open cell porosity should have adequate interconnectivity for a continuous flow of nutrients and outflow of cell metabolic residues as well as to allow cell growth into confluent layers. Blends of corn starch, a natural biodegradable polymer, with other synthetic polymers (poly(ethylene vinyl alcohol), poly(epsilon-caprolactone), poly(lactic acid)) were selected for this work because of their good balance of properties, namely biocompatibility, processability and mechanical properties. Melt spinning was used to produce fibers from all the blends and 3D meshes from one of the starch-poly(lactic acid) blends. The experimental characterization included the evaluation of the tensile mechanical properties and thermal properties of the fibers and the compression stiffness, porosity and degradation behavior of the 3D meshes. Light microscopy picture of 3D meshes.     

官能团化聚己内酯的合成与表征

通过分子结构设计合成了新型含有侧基官能团的聚己内酯材料.首先,通过亲核加成反应,由溴乙酸乙酯与烯胺合成2-乙氧甲酰甲基环己酮;然后以间氯过氧化苯甲酸为氧化剂,通过Baeyer-Villiger氧化反应,得到带有官能团的己内酯单体,6-乙氧甲酰甲基-ε-己内酯;该单体在异辛酸亚锡(Sn(Oct)2)的催化下,本体开环聚合得到相应的均聚物及其与ε-己内酯的共聚物.采用1H-NMR、13C-NMR、GPC和DSC表征了聚合物的结构和热力学性能.随着6-乙氧甲酰甲基-ε-己内酯在共聚物中的含量增加,共聚物的分子量降低,同时熔点和熔融焓也随之降低.     

Injectable Biodegradable Hydrogels

Injectable biodegradable copolymer hydrogels, which exhibit a sol–gel phase transition in response to external stimuli, such as temperature changes or both pH and temperature (pH/temperature) alterations, have found a number of uses in biomedical and pharmaceutical applications, such as drug delivery, cell growth, and tissue engineering. These hydrogels can be used in simple pharmaceutical formulations that can be prepared by mixing the hydrogel with drugs, proteins, or cells. Such formulations are administered in a straightforward manner, through site‐specific control of release behavior, and the hydrogels are compatible with biological systems. This review will provide a summary of recent progress in biodegradable temperature‐sensitive polymers including polyesters, polyphosphazenes, polypeptides, and chitosan, and pH/temperature‐sensitive polymers such as sulfamethazine‐, poly(β‐amino ester)‐, poly(amino urethane)‐, and poly(amidoamine)‐based polymers. The advantages of pH/temperature‐sensitive polymers over simple temperature‐sensitive polymers are also discussed. A perspective on the future of injectable biodegradable hydrogels is offered.

     

Stereocomplex Polylactide for Drug Delivery and Biomedical Applications: A Review

Polylactide (PLA) is among the most common biodegradable polymers, with applications in various fields, such as renewable and biomedical industries. PLA features poly(D-lactic acid) (PDLA) and poly(L-lactic acid) (PLLA) enantiomers, which form stereocomplex crystals through racemic blending. PLA emerged as a promising material owing to its sustainable, eco-friendly, and fully biodegradable properties. Nevertheless, PLA still has a low applicability for drug delivery as a carrier and scaffold. Stereocomplex PLA (sc-PLA) exhibits substantially improved mechanical and physical strength compared to the homopolymer, overcoming these limitations. Recently, numerous studies have reported the use of sc-PLA as a drug carrier through encapsulation of various drugs, proteins, and secondary molecules by various processes including micelle formation, self-assembly, emulsion, and inkjet printing. However, concerns such as low loading capacity, weak stability of hydrophilic contents, and non-sustainable release behavior remain. This review focuses on various strategies to overcome the current challenges of sc-PLA in drug delivery systems and biomedical applications in three critical fields, namely anti-cancer therapy, tissue engineering, and anti-microbial activity. Furthermore, the excellent potential of sc-PLA as a next-generation polymeric material is discussed.