智能水凝胶的制备以及在药物缓释方面的研究进展

介绍了温度、pH、电场、磁场、光,葡萄糖敏感型智能水凝胶的制备方法以及智能水凝胶在药物缓释控释领域的应用研究进展,并对未来智能水凝胶的发展方向做了展望。     

具有快速响应特性的环境响应型智能水凝胶的研究进展

环境响应智能水凝胶应用于化学传感器、化学微阀、人造肌肉、药物控释载体、物质分离等领域时常常需要快速响应特性,提高智能水凝胶的响应速率成为了智能水凝胶研究领域的重要课题之一。本文主要综述了具有快速响应特性的环境响应智能水凝胶的构建策略与方法,重点介绍了3类具有不同结构的快速响应型智能水凝胶,即具有多孔结构的快速响应智能水凝胶、具有梳状结构的快速响应智能水凝胶以及具有微球复合结构的快速响应智能水凝胶。     

多肽及蛋白质类药物智能释放系统的研究

智能高分子水凝胶是一类受外界环境的温度、pH值、光、电、磁、化学物质等的刺激,自身性质会随之发生变化的聚合物,具有传感、处理和执行功能。由于多肽及蛋白质药物生物半衰期短、稳定性差、在体内易被酶降解,因而限制了其应用范围。将多肽及蛋白质药物和智能高分子水凝胶组成智能药物控释系统,由此可控制药物脉冲释放,从而达到药物控制智能化的目的。本文概述了多肽及蛋白质药物智能控释系统的各种类型及应用研究。     

环境刺激响应型水凝胶及其在药物控释中的应用

环境刺激响应型水凝胶又称智能水凝胶,因为它能感应到外界环境因素的变化,并且发出响应,从而导致药物可在定点,定时、定量地释放,所以近年来受到普遍重视.该文综述了近年来响应水凝胶中温度敏感型、pH敏感型以及葡萄糖、电场、磁场、光等敏感型水凝胶及其在药物控释中的应用的最新进展,指出目前研究环境刺激响应型水凝胶存在的问题及今后...     

智能水凝胶的应用

智能水凝胶对于外界微小的物理化学刺激,如温度、电场、磁场、光、pH、离子强度或压力等能够感知并在响应过程中有显著的溶胀行为或响应性。本文重点介绍了智能水凝胶及与之密切相关的智能型大分子在药物控释、组织工程、活性酶的固定、调光材料等方面的应用。     

智能型高分子水凝胶在药物控释中的应用研究进展

智能型高分子水凝胶因为能感应到外界环境因素的变化,并且发出响应—凝胶的体积或其他性质发生显著变化,从而导致药物可在定点位置,定时、定量的释放,所以近年来受到普遍重视.本文综述了近年来智能型高分子水凝胶中温度敏感型、pH敏感型以及葡萄糖、电场、磁场、光、微波等敏感型水凝胶及其在药物控释中的应用,介绍了其控释作用机理及应用...     

产品开发

正环境刺激响应型高强智能水凝胶研发引人瞩目环境刺激响应型智能水凝胶能够对外界环境因素的变化产生显著的体积或其他特性的变化,且其性质和结构与生物组织类似,有望应用于传感器、人工肌肉、软体机器人、组织工程、化学反应开关或微阀、物质分离、药物控释等许多领域,具有很重要的意义和经济价值,其研发引人注目。近年来研发的主要有四类不同结构的环境刺激响应型高强智能水凝胶:超低交联结构水凝胶、纳米颗粒复合水凝胶、双网     

智能水凝胶在生物载药领域的研究进展

智能水凝胶是一类具有三维网络结构、膨胀性好、吸水性强、易保水、超仿生等特点的新型功能高分子材料。由于其合成过程中加入了具有特殊结构、基团的单体或者大分子原料,如聚丙烯酰胺(PNIPA)类大分子、酸/碱基团(如羧基和氨基)、丙烯酸、聚氨类、偶氮苯(As)、聚电解质(高分子链上有可以离子化的基团)等,因此智能水凝胶是能够根据环境的温度、酸度、电场、磁场等变化做出有规律的结构和体积调整,或者导致凝胶组成发生变化的新型智能生物化学水凝胶材料,具有较高的智能性和响应性。本文根据水凝胶对外界环境的刺激不同表现出不同的响应情况,将凝胶分为:温度敏感性水凝胶、pH敏感性水凝胶、光敏感性水凝胶、压力敏感性水凝胶、电场敏感性水凝胶等。近年来,随着人们对医用水凝胶和药物缓释研究的深入,具有环境敏感性和较好生物相容性的智能水凝胶成为临床上药物控释材料的首选。     

聚天冬氨酸水凝胶合成及其应用于药物控释的研究进展

聚天冬氨酸是一种新型的聚合氨基酸材料,具有很好的生物相容性、生物降解性。本文综述了聚天冬氨酸及其衍生物水凝胶的研究现状,介绍了化学交联、光交联、γ射线交联3种交联方法合成的聚天冬氨酸及其衍生物水凝胶,以及近年来聚天冬氨酸基凝胶对大分子蛋白药物、小分子抗炎性药物、抗癌和基因药物控释的研究进展,并对该凝胶在药物控释领域的发展方向进行了预测。     

聚己内酯药物控释材料的研究进展

综述了聚ε-己内酯(PCL)药物控释材料的研究进展,以及PCL微球、PCL纳米微粒、PCL纤维、PCL薄膜、PCL胶束、PCL水凝胶的制备方法及应用。PCL在药物控释领域研究中,可通过与其他聚合物共混或共聚来改善亲水性和控释行为。PCL共聚物也可应用到靶向给药系统中,靶向给药系统不仅能够将药物输送至病灶部位,还能实现定向释放。随着新材料的不断研发,构建新型智能药物控释系统的前景将更加广阔。     

pH敏感型半纤维素水凝胶的制备及释药性能研究

利用自由基聚合方法制备了丙烯酸和丙烯酰胺共聚接枝半纤维素水凝胶,研究了水凝胶在不同pH(1.5、7.4、10)缓冲液中的溶胀动力学,并以阿司匹林作为模型药物,研究了其在模拟胃肠液(pH=1.5、7.4)中的释放性能。结果显示,制备的半纤维素水凝胶对阿司匹林具有明显的缓释效果,有望实现药物的控制释放。     

Synthesis of smart hydrogels by radiation polymerisation for use as slow drug delivery devices

This article deals with the modification of medicinally important psyllium polysaccharide with acrylamide through radiation crosslinked polymerisation for the design of double potential hydrogels meant for slow release of insulin. Here the double potential is due to the inherent blood sugar lowering ability of psyllium and release of insulin in controlled manner from the drug loaded hydrogels. Synthesis of hydrogels and their characterisation by scanning electron micrography (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and swelling studies have been discussed. The release dynamics of model drug insulin from the hydrogels has been studied for the evaluation of the release mechanism. The release of the drug from the hydrogels occurred through non‐Fickian diffusion mechanism.     

A computational and experimental approach to develop minocycline-imprinted hydrogels and determination of their drug delivery performances

In this study, minocycline-imprinted hydrogels are developed for controlled drug delivery in ocular disease treatments. An integrated computational and experimental study are conducted for investigating the relationship between design parameters and the drug loading/release performance of hydrogels. First, suitable functional monomers are determined for successful drug-imprinting by studying pre-polymerization conditions with full-atom molecular dynamics (MD) simulations. MD simulations suggest that acrylic acid and itaconic acid are suitable monomers for imprinting minocycline. Then, minocycline-imprinted hydrogels are synthesized with acrylic acid, commonly used in hydrogels, and three different amounts of cross-linker ethylene glycol dimethacrylate, 1, 2 and 3 mol%. All hydrogels are characterized and their drug loading and release performances are determined. Our computational and experimental calculations indicate an optimum cross-linker amount of 2 mol% for controlled minocycline release from imprinted hydrogels with an imprinting factor of almost 3. Finally, the drug release kinetics are determined by Korsmeyer-Peppas model.     

Effect of anionic/siloxy groups on the release of ofloxacin from soft contact lenses

For the treatment of ocular diseases, chemotherapeutic antibiotics, for example, Ofloxacin, are usually administrated through the application of eye drops during ophthalmic perioperative sterilization. However, this approach has several drawbacks, such as the need for frequent application caused by tears draining the drugs out of the eyes or the presence of a possible contraindication of eye drops when contact lenses are worn. To overcome these problems, we have studied contact lenses composed of hydrogels, which function as a type of drug delivery system technology. We synthesized hydrogels to be used as contact lenses with sufficient amounts of drug uptake and release profiles for sterilization treatment during the perioperative period in ophthalmic areas. This study showed that the hydrogels that included side‐chain ionic groups and silyl groups were useful materials to prepare drug delivery contact lenses. The ionic groups in the hydrogels could functionally retain a drug if an ionic substituent was present. It is noteworthy that the drug content in the contact lenses could readily be controlled by changing the ratio of ionic monomer contents during polymerization. Furthermore, the controlled drug release of silyl‐group‐containing hydrogels showed sustained release over 72 h, which indicated that the hydrogels could be used as contact lenses for sustained drug release. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013     

Novel physically crosslinked hydrogels of carboxymethyl chitosan and cellulose ethers: Structure and controlled drug release behavior

Novel hydrogels, physically crosslinked by hydrogen bonding of component polymers, were obtained by mixing aqueous solutions of carboxymethylchitosan (CMCS) with cellulose ethers including hydroxyethylcellulose (HEC) and methylcellulose (MC). The hydrogels were characterized by IR, XPS, WAXD, and SEM. The swelling and controlled drug release behaviors of hydrogels were also studied. The results indicate that intermacromolecular hydrogen bonding in CMCS/HEC is stronger than that in CMCS/MC. The swelling and drug release rate of hydrogels decrease as the interaction of component polymers increases. Both the swelling and drug release from hydrogels can be controlled by component polymer ratio. The hydrogels may be potential candidates for biomedical applications. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Nafcillin release from poly(acrylic acid–co–methyl methacrylate) hydrogels

Summary Copolymeric poly(acrylic acid-co-methyl methacrylate) hydrogels for three different compositions: (90/10), (80/20) and (60/40), have been studied. Drug release has been examined as a function of the hydrogel composition by HPLC (High Pressure Liquid Cromatography). The release experiments were carried out at 37 °C. The fraction of available drug release was linear in t^1/2. The values of the diffusional coefficient (0.50<n<1.0) indicate that the nafcillin release mechanism from the hydrogels in study is non-Fickian. The diffusion coefficients for this drug release have been calculated. The molecular diffusion of nafcillin through hydrogels is controlled by the swelling.     

Formation of silk fibroin hydrogel and evaluation of its drug release profile

Silk hydrogels are interesting materials to be used as matrix in controlled drug delivery devices. However, methods to accelerate fibroin gelation and allow the drug incorporation during the hydrogel preparation are needed in literature. In this article we report the preparation of silk fibroin hydrogels with addition of several contents of ethanol, used to accelerate fibroin gelation kinetics, and we also evaluate the potential of these hydrogels to be used as matrices for drug delivery. Chemical and conformational properties did not change despite the amount of ethanol incorporated in the hydrogel. Hydrogels containing diclofenac sodium dissolved in ethanol showed a faster initial release of the drug than hydrogels with the drug dissolved in water but equilibrium was reached later. This indicates a more sustained drug delivery from hydrogels in which the model drug was dissolved in ethanol. Fibroin hydrogels confirm their promising use as biopolymeric matrices for controlled drug release. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41802.     

PLA Microspheres-Embedded PVA Hydrogels Prepared by Gamma-Irradiation and Freeze-Thaw Methods as Drug Release Carriers

A drug delivery system based on poly (vinyl alcohol) (PVA) hydrogels containing ibuprofen-loaded poly (lactic acid) (PLA) microspheres was developed to improve the release kinetics of this model drug. Gamma-irradiation and freeze-thawing were applied to prepare poly (vinyl alcohol) hydrogels. Properties and morphology of these composite hydrogels were investigated using FTIR, DSC, and SEM. In vitro release indicated that entrapment of the microspheres into the PVA hydrogels causes a reduction in both the release rate and the initial burst effect. PLA microspheres entrapped into the PVA hydrogels showed more suitable controlled release kinetics for drug delivery.     

Preparation a novel pH‐sensitive blend hydrogel based on polyaspartic acid and ethylcellulose for controlled release of naproxen sodium

Hydrogels based on pH‐sensitive polymers are of great interest as potential biomaterials for the controlled delivery of drug molecules. In this study, a novel, pH‐sensitive hydrogel was synthesized by poly(aspartic acid) (PASP) crosslinked with 1,6‐hexanediamine and reinforced with ethylcellulose (EC). The loading and release characteristics of naproxen sodium (NS) were studied. The PASP–EC blend hydrogels had pH‐sensitive characteristics and were strongly dependent on the pH value. The release kinetics for NS from the PASP–EC blend hydrogels and PASP hydrogel were evaluated in simulated gastric fluid (pH = 1.05) and simulated intestinal fluid (pH = 6.8) at 37°C. The results showed that the drug‐loaded hydrogels were resistant to simulated gastric fluid, and hence, they could be useful for oral drug delivery. Compared with the PASP hydrogel, the PASP–EC blend hydrogels showed a lower release rate of NS in the same pH conditions. It was evident that the presence of hydrophobic groups (EC) retarded the release of NS and led to sustained release. The kinetics of NS release from the drug‐loaded hydrogels conformed to the Korsmeyer–Peppas model. The release exponent of the model was 0.7291, which indicated multiple drug release. The PASP–EC blend hydrogels were biodegradable and pH sensitive; there would be a wide range of applications for them in controlled drug‐delivery systems. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Low-methoxyl pectin–zeolite hydrogels controlling drug release promote in vitro wound healing

This study presents the design of novel hydrogel films, based on low-methoxyl (LM) pectin and NaA- or ZnA-zeolite particles, to serve as wound dressing materials with controlled drug delivery properties. We studied the effects of the preparation method of hydrogels, the amounts of crosslinker, drug and zeolite, and the type of cation in zeolites on the drug release mechanisms from the hydrogels. Ionic strengths of both film and external medium dictated the drug release behavior of the films, while the other parameters also played essential roles. NaA-zeolite hydrogels prepared using membrane diffusion controlled system, could reach a drug release ratio of 86% within 5 h. The drug-free hydrogels displayed no cytotoxicity while supporting cell proliferation and migration. Our cost-effective LM pectin–zeolite hydrogels promise to be effective wound dressing materials with controlled drug delivery ability, transparency, good swelling properties, ability to hold fluids, good oxygen transmission rate, and biocompatibility. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47640.