新型可生物降解医用高分子材料-聚膦腈

聚磷腈是一族由交替的氮、磷原子以交替的单键、双键构成无机主链的新型可生物降解聚合物。聚膦腈具有独特的性质和显著的合成多样性,降解产物为磷酸、氨、氨基酸和乙醇等无毒物质。通过改变聚膦腈侧链结构和组成,可调节聚膦腈的降解速度,控制药物释放的速度。本文主要综述了聚膦腈的合成、降解及其在药物控释系统中的应用。     

温敏性氨基酸-聚合物杂化材料的研究进展

温敏性聚合物在组织工程、药物传递和缓释、生物传感器以及纳米药物中有着广泛的应用。聚N-异丙基丙烯酰胺,聚甲基丙烯酸寡聚乙二醇酯以及吡咯烷酮基聚合物是典型的温敏性聚合物。然而,这些温敏性聚合物功能相对单一。现代科技的发展,对温敏性材料提出了新的要求,如具有多重刺激响应特性、生物相容性好、可生物降解以及其他功能。氨基酸是两性分子,具有手性、生物相容性好、多官能团、二级结构丰富等优点。以氨基酸或多肽构筑温敏聚合物可以将聚合物的多样性与氨基酸的优点结合起来,本文介绍了此类材料的合成及研究进展。     

聚膦腈在药物控释系统中的应用

聚膦腈由于其具有良好的生物相容性，可生物降解性及易于功能化的特性而成为一类独特的药物控释材料。本文就疏水性线型聚膦腈，聚膦腈水凝胶及聚膦腈高分子药物在药物控释系统中的应用作一简要综述。     

药物缓释载体用温敏性水凝胶

近年来温敏性水凝胶作为药物缓释载体的研究十分广泛。本文在简要介绍了温敏性水凝胶的结构与性质、蛋白质的包埋技术和释药机理后,较为详细地综述了温敏性水凝胶在药物控制释放领域中的应用情况。     

生物可降解聚膦腈材料的功能化及研究进展

聚膦腈是一类主链由磷氮原子交替组成,每个磷原子带有两个有机官能团侧基的有机-无机杂化高分子,其化学结构强大的可设计性赋予了材料丰富的理化性能。作为生物学用途的聚膦腈材料,生物相容性、生物可降解性和功能化改性是实现其应用的关键因素。本文从数种功能化聚膦腈(如光致荧光、导电、聚膦腈-聚酯共聚物)的制备、聚膦腈的降解机理和降解行为调控,以及生物可降解聚膦腈作为组织工程支架材料、药物载体材料和基因转染材料等几个方面,较为全面地综述了聚膦腈生物医用高分子的研究进展。     

氨基酸酯-烷基醚混合取代聚膦腈的合成与表征

聚膦腈高聚物,因其良好的生物相容性而用作生物医用材料。若在其侧链引入对热(如烷氧基醚)或对pH值敏感和可生物降解的基团(如氨基酸酯),则可得到具有环境敏感性和可生物降解性能的高聚物,这些高聚物可望作为药物载体,用于药物的控制释放。     

化学交联葡萄糖基取代聚膦腈水凝胶制备和胰岛素释放研究

在合成了葡萄糖基和甲氧乙氧基共取代聚膦腈的基础上,进一步通过向聚膦腈主链引入一定量带自由氨基的取代基,与戊二醛反应交联后,获得了具有化学交联点的聚膦腈水凝胶.该水凝胶与伴刀豆球蛋白(Con A)结合后,水凝胶的溶涨平衡性能表现出对葡萄糖浓度的依赖性.将负载有胰岛素的聚膦腈水凝胶交替置于含不同葡萄糖浓度(4 mg/mL和1 mg/mL)的介质中,可检测到在高浓度葡萄糖环境下,胰岛素的释放明显加快,而当葡萄糖的浓度降低后,在一段时间内几乎检测不到胰岛素的释放,但随着浸泡时间的延长,仍会逐渐出现胰岛素从凝胶缓慢扩散释放的现象.以上研究表明,化学交联的葡萄糖基取代聚膦腈水凝胶可用于对胰岛素的葡萄糖响应释放.     

直链淀粉交联氨基酸酯取代聚膦腈杂化材料的制备

利用直链淀粉与甘/丙氨酸乙酯共取代聚膦腈交联, 制得了一种具有网络结构的新型杂化材料. 实验结果表明, 淀粉衍生物上的羟基转变为醇钠后, 可与聚膦腈分子链上的P-Cl键发生亲核取代反应; 所得聚合物膜无明显相分离, 力学性能优于具有相似组成的直链淀粉/聚膦腈共混膜, 表面亲水性和吸水率与对应的共混膜接近, 且均高于纯聚膦腈膜. 因此, 该聚合物可作为杂化生物材料用于药物控制释放和组织工程方面的研究.     

温敏性水杨酸分子印迹水凝胶的合成与性能研究

以水杨酸为模板分子,丙烯酰胺为功能单体,N-异丙基丙烯酰胺为温敏单体,乙二醇二甲基丙烯酸酯为交联剂,偶氮二异丁腈为引发剂,采用本体聚合法,60℃热聚合制备了温度敏感的分子印迹(MIP)水凝胶,其最低临界溶解温度(LCST)在40℃左右.该分子印迹水凝胶对水杨酸显示了高的选择识别性,非分子印迹水凝胶则表现出低的选择性.温敏性分子印迹水凝胶的吸附容量达6.35 mg/g,是非印迹水凝胶的3.66倍.相对于未添加温敏单体的分子印迹聚合物,温敏性水杨酸分子印迹水凝胶对目标分子的吸附和洗脱效率分别提高33.3％和50％,并实现了温度响应的水凝胶结合、释放水杨酸的功能.     

温度敏感性药物载体及其在肿瘤热化疗中的应用

温度敏感性材料由于其理化性质对温度变化高度敏感,同时相变温度又易于调控,因而成为条件响应型药物控释载体中的研究热点。多种类型的温敏性药物载体,包括脂质体、聚合物囊泡、聚合物胶束,经过多年的研究和优化,其稳定性得到进一步的提高,而相变温度也实现了在较宽范围内的随意调整,可同时适用于病理性的高热和局部人工热疗等多种方式的温敏靶向性释药。并且,由于局部热疗可以有效控制温敏载体的药物释放,同时,热疗还能有效增强化疗药物的细胞毒性,因此温敏药物载体在肿瘤化疗和热化疗领域具有独特的应用潜力。本综述简要回顾了温敏性载体在药物载体领域的研究现状。在此基础上,从对肿瘤热化疗原理、发展现状、疗效影响因素的角度,进一步综述了温敏性药物载体在肿瘤热化疗领域的研究进展,特别关注了复合型温敏载体,因为这类载体结合了具有光热/磁热效应的纳米颗粒而兼具自升温能力,因而在靶向性热化疗中独具优势。最后,本文结合热化疗的影响因素,对温敏性载体在肿瘤热化疗领域的发展方向进行了展望。     

Injectable and biodegradable hydrogels: gelation, biodegradation and biomedical applications

Injectable hydrogels with biodegradability have in situ formability which in vitro/in vivo allows an effective and homogeneous encapsulation of drugs/cells, and convenient in vivo surgical operation in a minimally invasive way, causing smaller scar size and less pain for patients. Therefore, they have found a variety of biomedical applications, such as drug delivery, cell encapsulation, and tissue engineering. This critical review systematically summarizes the recent progresses on biodegradable and injectable hydrogels fabricated from natural polymers (chitosan, hyaluronic acid, alginates, gelatin, heparin, chondroitin sulfate, etc.) and biodegradable synthetic polymers (polypeptides, polyesters, polyphosphazenes, etc.). The review includes the novel naturally based hydrogels with high potential for biomedical applications developed in the past five years which integrate the excellent biocompatibility of natural polymers/synthetic polypeptides with structural controllability via chemical modification. The gelation and biodegradation which are two key factors to affect the cell fate or drug delivery are highlighted. A brief outlook on the future of injectable and biodegradable hydrogels is also presented (326 references).     

Chitosan Nanoparticles-Insight into Properties,Functionalization and Applications in Drug Delivery and Theranostics

Nanotechnology-based development of drug delivery systems is an attractive area of research in formulation driven R&D laboratories that makes administration of new and complex drugs feasible. It plays a significant role in the design of novel dosage forms by attributing target specific drug delivery, controlled drug release, improved, patient friendly drug regimen and lower side effects. Polysaccharides, especially chitosan, occupy an important place and are widely used in nano drug delivery systems owing to their biocompatibility and biodegradability. This review focuses on chitosan nanoparticles and envisages to provide an insight into the chemistry, properties, drug release mechanisms, preparation techniques and the vast evolving landscape of diverse applications across disease categories leading to development of better therapeutics and superior clinical outcomes. It summarizes recent advancement in the development and utility of functionalized chitosan in anticancer therapeutics, cancer immunotherapy, theranostics and multistage delivery systems.     

Chitosan nanoparticles: a promising system in novel drug delivery

The ability of nanoparticles to manipulate the molecules and their structures has revolutionized the conventional drug delivery system. The chitosan nanoparticles, because of their biodegradability, biocompatibility, better stability, low toxicity, simple and mild preparation methods, offer a valuable tool to novel drug delivery systems in the present scenario. Besides ionotropic gelation method, other methods such as microemulsion method, emulsification solvent diffusion method, polyelectrolyte complex method, emulsification cross-linking method, complex coacervation method and solvent evaporation method are also in use. The chitosan nanoparticles have also been reported to have key applications in parentral drug delivery, per-oral administration of drugs, in non-viral gene delivery, in vaccine delivery, in ocular drug delivery, in electrodeposition, in brain targeting drug delivery, in stability improvement, in mucosal drug delivery in controlled drug delivery of drugs, in tissue engineering and in the effective delivery of insulin. The present review describes origin and properties of chitosan and its nanoparticles along with the different methods of its preparation and the various areas of novel drug delivery where it has got its application.     

Recent advances in biopolymer based electrospun nanomaterials for drug delivery systems

Drug delivery systems, including liposomes, gels, prodrugs, and so forth, are used to enhance the tissue benefit of a pharmaceutical drug or conventional substance at a specific diseased site with little toxicological impact. Nanotechnology can be a rapidly developing multidisciplinary science that enables the production of polymers at the manometer scale for different medical applications. The use of biopolymers in drug delivery systems provides compatibility, biodegradability and low immunogenicity biologically. Large-scale and smaller-than-expected medication particles can be delivered using biopolymers such as silk fibroins, collagen, gelatine, and others that are easily formed into suspensions. These drug carrier systems are functional at improving drug delivery and can be used in intranasal, transdermal, dental, and ocular delivery systems. This study discusses the latest developments in drug delivery methods based on nanomaterials, mainly using biopolymers like proteins and polysaccharides.     

DNA纳米结构在药物转运载体和智能载药中的应用进展

纳米材料具有荷载效率高、靶向性能好、半衰期较长等优点, 非常适于作为药物转运载体, 可有效提高药物的水溶性、稳定性和疾病治疗效果.目前, 开发具有良好生物相容性、可控靶向释放能力和精确载药位点的理想药物转运载体, 仍是该领域存在的挑战性问题和当前研究的重点.自组装DNA纳米结构是一类具有精确结构、功能多样的纳米生物材料, 具有良好的生物相容性和稳定性、较高的膜渗透性和可控靶向释放能力等优点, 是理想的药物转运载体和智能载药材料.本文总结了DNA纳米结构的发展历程、DNA纳米结构作为药物转运载体的研究现状、动态DNA纳米结构在智能载药中的应用进展, 并对其发展前景进行了展望.     

Advances in Targeting Drug Biological Carriers for Enhancing Tumor Therapy Efficacy

Chemotherapy drugs continue to be the main component of oncology treatment research and have been proven to be the main treatment modality in tumor therapy. However, the poor delivery efficiency of cancer therapeutic drugs and their potential off-target toxicity significantly limit their effectiveness and extensive application. The recent integration of biological carriers and functional agents is expected to camouflage synthetic biomimetic nanoparticles for targeted delivery. The promising candidates, including but not limited to red blood cells and their membranes, platelets, tumor cell membrane, bacteria, immune cell membrane, and hybrid membrane are typical representatives of biological carriers because of their excellent biocompatibility and biodegradability. Biological carriers are widely used to deliver chemotherapy drugs to improve the effectiveness of drug delivery and therapeutic efficacy in vivo, and tremendous progress is made in this field. This review summarizes recent developments in biological vectors as targeted drug delivery systems based on microenvironmental stimuli-responsive release, thus highlighting the potential applications of target drug biological carriers. The review also discusses the possibility of clinical translation, as well as the exploitation trend of these target drug biological carriers.     

Advanced Silk Fibroin Biomaterials-Based Microneedles for Healthcare

Microneedles are a promising transdermal drug delivery system that has the advantages of minimal invasiveness, painlessness, and on-demand drug delivery compared with commonly used medical techniques. Natural resources are developed as next-generation materials for microneedles with varying degrees of success. Among them, silk fibroin is a natural polymer obtained from silkworms with good biocompatibility, high hardness, and controllable biodegradability. These properties provide many opportunities for integrating silk fibroin with implantable microneedle systems. In this review, the research progress of silk fibroin microneedles in recent years is summarized, including their materials, processing technology, detection, drug release methods, and applications. Besides, the research and development of silk fibroin in a multidimensional way are analyzed. Finally, it is expected that silk fibroin microneedles will have excellent development prospects in various fields.     

Whey protein: A functional and promising material for drug delivery systems recent developments and future prospects

Natural polymers have been extensively utilized in the past decades due to their outstanding features. Among these natural excipients, protein‐based polymers have superb features owing to their high drug binding capacity and biodegradability. Whey protein is a versatile protein‐based vehicle for drug delivery systems. It has been shown to be nontoxic, biocompatible, and biodegradable. Therefore, it has been considered as an ideal biomaterial for the design of advanced drug delivery systems. Protein‐based cargo acts as synthetic polymers counterpart for innovative delivery systems. The current review is mainly focused on application of whey proteins as an emerging carrier in drug delivery systems, achieved during the past.     

Zinc-Based Metal-Organic Frameworks in Drug Delivery,Cell Imaging,and Sensing

The design and structural frameworks for targeted drug delivery of medicinal compounds and improved cell imaging have been developed with several advantages. However, metal-organic frameworks (MOFs) are supplemented tremendously for medical uses with efficient efficacy. These MOFs are considered as an absolutely new class of porous materials, extensively used in drug delivery systems, cell imaging, and detecting the analytes, especially for cancer biomarkers, due to their excellent biocompatibility, easy functionalization, high storage capacity, and excellent biodegradability. While Zn-metal centers in MOFs have been found by enhanced efficient detection and improved drug delivery, these Zn-based MOFs have appeared to be safe as elucidated by different cytotoxicity assays for targeted drug delivery. On the other hand, the MOF-based heterogeneous catalyst is durable and can regenerate multiple times without losing activity. Therefore, as functional carriers for drug delivery, cell imaging, and chemosensory, MOFs’ chemical composition and flexible porous structure allowed engineering to improve their medical formulation and functionality. This review summarizes the methodology for fabricating ultrasensitive and selective Zn-MOF-based sensors, as well as their application in early cancer diagnosis and therapy. This review also offers a systematic approach to understanding the development of MOFs as efficient drug carriers and provides new insights on their applications and limitations in utility with possible solutions.