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基于温敏水凝胶的可调胶体晶体制备 总被引:1,自引:1,他引:0
基于单分散胶体粒子悬浊液在温敏水凝胶表面可以形成湿润型胶体晶体的现象, 利用温敏水凝胶对水的控释作用制备了温度敏感的可调制胶体晶体. 在室温下利用提拉法在温敏水凝胶聚N-异丙基丙烯酰胺(PNIPAAm)表面制备湿润型胶体晶体膜. 由于胶体粒子的有序排列, 胶体晶体显示出一个尖锐的反射峰. 当温度上升到34 ℃以上时, 由于PNIPAAm水凝胶中的水被释放, 导致胶体晶体中粒子浓度降低, 粒子间距增加; 反射峰发生红移. 这些特性可以通过温度变化进行调制. 相似文献
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合成水凝胶是由水溶性单体聚合得到的轻度交联的高分子柔顺链网络 .高分子交联网络与水之间的相互作用决定着水凝胶的物理化学性质[1,2 ] .水凝胶常应用于生物医学材料和生物传感器等方面 .如接触眼镜的材料就常用甲基丙烯酸 -β-羟乙酯和聚乙烯醇 (PVA)为主要成分的水凝胶 ,所以对其摩擦性质的研究会丰富对生物医用材料的认识 .关于水凝胶的摩擦性质的研究 ,除 Osada等[3] 研究了聚乙烯醇及一些天然水凝胶在几牛顿到几十牛顿的负载下的摩擦行为外 ,尚少报道 .PVA水凝胶的结晶度对其性能影响甚大 ,但他们没有涉及结晶度与 PVA水凝胶的摩… 相似文献
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利用聚乙二醇(PEG 1000)引发乙交酯和 D,L-丙交酯开环共聚合, 制备了聚丙交酯乙交酯(PLGA)三嵌段共聚物(PLGA-PEG-PLGA)温敏水凝胶材料; 利用核磁共振氢谱( 1H NMR)确定了产物的结构及组成. 通过还原硝酸银的方法制备银纳米粒子(AgNPs), 并将其与PLGA-PEG-PLGA三嵌段共聚物水凝胶混合, 制得新型AgNPs/PLGA-PEG-PLGA复合水凝胶; 对该复合水凝胶的相关性能进行了表征. AgNPs/PLGA-PEG-PLGA复合水凝胶仍然具有温敏性能, 随着温度升高可发生溶胶-凝胶的相转变; 还可以持续释放银纳米粒子, 从而发挥抗菌性能. 体外细胞实验结果表明, AgNPs/PLGA-PEG-PLGA复合水凝胶具有良好的生物相容性, 未见明显细胞毒性, 是具有应用前景的新型复合水凝胶. 相似文献
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采用自由基聚合法在水溶液中制备了温敏水凝胶聚N-异丙基丙烯酰胺(PNIPAAm),以非水溶性药物布洛芬(IBU)为模型药物分子,研究了该水凝胶的温敏性能及与药物IBU的相互作用,考察了不同温度下(25 ℃和37 ℃)IBU在磷酸盐缓冲溶液(PBS,pH=7.4)中的释放行为.研究结果表明:该水凝胶的最低临界溶解温度(L... 相似文献
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Blindness is one of the most feared disabilities. From cataracts and glaucoma to age-related macular degeneration and retinal vascular diseases, ocular diseases have adverse impacts on patients and pose a huge burden to the healthcare system. The World Health Organization estimates that out of 2.2 billion people with visual impairment, almost half of the cases can be prevented or has yet to be addressed. This presents an urgent clinical and societal need to be met. Temperature-sensitive hydrogels are one of the most biocompatible materials, which can be applied into the eye. By exploiting physiological temperature as a stimulus for in situ gel formation, control of the mechanical properties, rate of drug release, and biomechanical interactions can be tuned. They are very versatile and have immense potential in ocular applications by acting as vitreous substitutes in retinal surgery or topical eye drops and lenses for ocular discomfort and inflammation. In this article, we provide a review of the recent developments in temperature-responsive polymers in ophthalmic therapy in the past 5 years including retinal detachment, retinal vascular diseases, dry eyes, cataracts, age-related macular degeneration, and glaucoma. 相似文献
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This review describes the role of contact lenses as an innovative drug delivery system in treating eye diseases. Current ophthalmic drug delivery systems are inadequate, particularly eye drops, which allow about 95% of the active substance to be lost through tear drainage. According to the literature, many interdisciplinary studies have been carried out on the ability of contact lenses to increase the penetration of topical therapeutic agents. Contact lenses limit drug loss by releasing the medicine into two layers of tears on either side of the contact lens, eventually extending the time of contact with the ocular surface. Thanks to weighted soft contact lenses, a continuous release of the drug over an extended period is possible. This article reviewed the various techniques to deliver medications through contact lenses, examining their advantages and disadvantages. In addition, the potential of drug delivery systems based on contact lenses has been extensively studied. 相似文献
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快速精准的诊断和高效的治疗对于减轻眼部疾病造成的危害至关重要. 在过去的几十年里, 由于具有尺寸小、 比表面积大、 表面易修饰及独特的光/电子/机械性能等优点, 纳米材料已被用于构建不同种类的高性能纳米探针. 其中, 基于其良好的生物相容性, 科学家们已经将硅纳米材料设计为可用于不同眼部疾病诊断与治疗的功能化纳米探针. 本综述主要概述了将硅基纳米探针用于检测和治疗不同眼部疾病(如角膜疾病、 视网膜疾病、 青光眼等)的近期研究进展. 首先, 重点介绍了硅基纳米探针的设计制备及在角膜新生血管、 细菌性角膜炎等角膜疾病的成像检测与治疗中的应用; 然后, 介绍了用于成像检测和治疗视网膜疾病(如色素性视网膜炎和视网膜新生血管)的硅基持续性给药系统的研究成果; 随后, 概述了多功能硅基纳米载药系统的构建及在青光眼治疗领域的应用研究进展; 最后, 简要讨论了将硅基纳米探针用于眼部疾病诊治面临的挑战并对未来的发展前景进行了展望. 相似文献
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Phase I and phase II ocular metabolic activities and the role of metabolism in ophthalmic prodrug and codrug design and delivery 总被引:1,自引:0,他引:1
While the mammalian eye is seldom considered an organ of drug metabolism, the capacity for biotransformation is present. Compared to the liver, the metabolic capabilities of the eye are minuscule; however, phase I and phase II metabolic activities have been detected in various ocular structures. The careful consideration of ocular tissue metabolic processes within the eye has important implications for controlling the detoxification of therapeutic agents and for providing the potential for site-specific bio-activation of certain drug molecules, thus enabling significant improvements in drug efficacy and the minimization of side-effect from either local or systemic drug delivery to the eye. Knowledge of these processes is important to prodrug and codrug development and to researchers involved in the design, delivery and metabolism of ophthalmic drugs. This present article reviews the progress in ocular prodrug and codrug design and delivery in light of ocular metabolic activities. 相似文献
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Challenges and opportunities to development of ocular drug delivery systems and nanomedicines for pediatric patients are reviewed. 相似文献
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Blindness and vision impairment are major global health problems. Effective ophthalmic drug delivery poses a significant challenge because of protective physiological barriers and various biological clearance mechanisms that result in extremely low ocular bioavailability. Over the past several decades, several safe and effective ophthalmic drug delivery approaches have been promoted to combat these problems and to improve ocular bioavailability. Among these approaches, the stimulus‐responsive hydrogel for topical drug delivery has gained increasing attention because of its prolonged drug retention at the local site and enhanced ocular bioavailability. This review summarizes and presents recent advances and perspectives of a stimulus‐responsive hydrogel for ophthalmic drug delivery. 相似文献
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Chandrashekhar Mahadeo Chakole P.K. Sahoo Jaya Pandey Meenakshi Kanwar Chauhan 《印度化学会志》2022,99(2):100323
Brinzolamide is a carbonic anhydrase inhibitor used in the eye drop form for the treatment of glaucoma. It requires frequent dosing to attain therapeutic concentration. Therefore, this study aimed to prepare sustained ocular drug delivery of brinzolamide. The objective of the study was to prepare a hydrogel loaded with a nanostructured lipid carrier (NLC) of brinzolamide. The hydrogel was prepared by a green synthesis approach using genipin as a natural crosslinking agent and polymers such as carboxymethyl chitosan and poloxamer 407. The melt emulsification-ultra sonication method was used to prepare a nanostructured lipid carrier of brinzolamide, which was loaded into a hydrogel using a swelling and loading method. The NLC formulation has shown small particle sizes of 111.20 ?± ?2.15 ?nm, polydispersity index of 0.280 ?± ?0.005 and % entrapment efficiency of 82.16% ?± ?0.14%. The NLC-loaded hydrogels of brinzolamide formulations were studied for swelling properties and showed temperature and pH-responsive swelling behavior. The optimized hydrogel formulation has been studied for in vitro drug release and showed drug release for a longer duration (24 ?h) than marketed eye drops (8 ?h). In an ex vivo study, hydrogel formulations showed transcorneal permeability 4.54 times greater than marketed eye drops. The hydrogel formulation of brinzolamide produced by the green synthesis method has shown sustained-release properties with no sign of ocular irritation. Hence, the hydrogel of brinzolamide-loaded NLC would be the potential drug delivery approach in the near future for sustained ocular drug delivery in glaucoma management. 相似文献
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Advances in recombinant techniques have led to the development of genetically engineered polymers with exquisite control over monomer sequence and polymer length. The ability to study how precise structures correlate with function has provided opportunities for the utility of these polymers in drug delivery. Chemically derived and developed methods of synthesis have yielded many useful polymers for drug delivery to-date, including those currently used in patients. However they have drawbacks, including limitations involved in statistical characterization of conventional polymer synthetic techniques. Encoding at the genetic level and production of such recombinant polymers in organisms allow for precise order and accuracy of amino acid residues and production of monodisperse polymers with specific function and physicochemical properties. Research into elastin-like, silk-like, and silk-elastinlike protein polymers for example has led to the development of delivery systems based on natural motifs of structural proteins to take advantage of their physicochemical properties. Additionally, protein based polymers on other natural motifs and de novo designs are starting to produce promising constructs for drug and gene delivery applications where precise control over structure promises correlation with function and guides the development of new and improved constructs. Clinical applications based on recombinant polymers for delivery of bioactive agents have not been realized at this point. However lessons learned from fundamental research with these polymers can be used to guide design of safe and effective systems for use in the clinic. This tutorial review summarizes progress made in the design and utility of recombinant polymers in drug and gene delivery and discusses challenges and future directions of such polymers for this purpose. 相似文献
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A highly selective fluorescent probe for visualizing dry eye disease-associated viscosity variations
《中国化学快报》2023,34(10):108516
Dry eye disease (DED) is a multifactorial chronic inflammatory disease of the ocular surface with complex and unclear etiology. The development of reliable detection tools for the pathology of DED will benefit its treatment, but it is still lacking. In parallel, it has been discovered recently that viscosity changes are involved in inflammation processes. In this regard, we constructed a fluorescent probe V5 with an asymmetric donor-acceptor-donor (D-A-D) feature after rational structural modulation for viscosity detection during DED progression. The probe manifested a remarkable fluorescence enhancement (110 folds) in highly viscous conditions without interferences from polarity and reactive species. Specifically, no aggregation effect of the probe was found in glycerol. Moreover, viscosity increment in human corneal epithelial cells (HCECs) induced by hyperosmosis and inflammation was monitored, and ferroptosis in HCECs also led to the viscosity elevation. A reactive oxygen species (ROS)-dependent viscosity changes during DED progression is demonstrated. Finally, viscosity change in corneal epithelial cell layer from mice treated by scopolamine was also visualized for the first time. We anticipate this work can provide a new lens to the pathogenesis study and diagnosis of DED and other ophthalmic diseases using fluorescence methods. 相似文献
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金属有机骨架材料(MOFs)是指由含氮、氧等多齿有机配体与金属离子通过自组装形成的配位聚合物。由于金属有机骨架材料的大比表面积和高孔隙率等优点使其在药物负载领域有广泛应用。近年来,纳米金属有机骨架材料(NMOFs)因既具有MOFs的特点,又具有纳米材料独特的理化性能,使其兼具药物负载量高、目标靶向性好、表面易改性和生物相容性优良等特点,已成为一种优异的纳米级载药系统。本文介绍了NMOFs的常用制备方法,主要包括溶剂热法、反相微乳液法与超声波法,并对其优缺点进行了讨论;详细阐述了载药NMOFs的特性及其不同类型对于各类药物的负载能力;指出今后其主要的研究方向是改善生物相容性、实现更有效的表面功能化、扩展生物NMOFs及其负载药物的种类,使其应用到更多疾病的治疗上。 相似文献