Preparation and characterization of co-processed starch/MCC/chitin hydrophilic polymers onto magnesium silicate

It was aimed to investigate the compressibility, compactibility, powder flow and tablet disintegration of a new excipient comprising magnesium (Mg) silicate co-processed (5%–85% w/w) onto chitin, microcrystalline cellulose (MCC) and starch as the hydrophilic polymers of interest. Initially, the mechanism of tablet disintegration was studied by measuring water infiltration rate, moisture sorption, swelling capacity and hydration ability. Moreover, the powders compression behavior was carried out by applying Kawakita model of compression analysis in addition to porosity and radial tensile strength measurements. In vitro drug release of compacts made of 400?mg ibuprofen and 300?mg of the hydrophilic polymers containing 30% w/w Mg silicate co-precipitate was investigated in phosphate buffer (pH 7.8). This work demonstrated that the incorporation of Mg silicate to the hydrophilic polymers lead to the improvement of powder flowability, compactibility, stability (with regard to storage conditions), compacts crushing strength, and disintegration time in addition to faster drug release. The overall findings are practically advantageous in the context of finding a low cost and multifunctional co-processed excipient of natural origins.     

改性甲壳素生物敷料用于新鲜创面患者的临床疗效观察

皮肤是维持内环境稳定和阻止微生物入侵的屏障。损伤后发生的许多局部和全身问题与丧失皮肤屏障有关。一个性能优良的创面覆盖物，可暂时起到皮肤屏障功能的部分作用，提供一个有利于创面愈合的环境，等待创面上皮化为了促进手术后患者的伤口愈合，减少疤痕组织形成，预防感染的发生，减少和控制抗生素的应用，提高治疗效果。我们对甲壳素敷料与一次性自粘无菌敷料进行了比较，现将结果报告如下。     

甲壳素/壳聚糖在疝修补领域的研究综述

疝气是目前临床上1 种常见的外科疾病,随着疝气患者的日益增多,疝修补材料的不断革新成为临床疝气领域的研发热点,力求通过改善疝修补材料来促进疝修补术后的腹壁组织修复情况。目前海洋来源的甲壳素/壳聚糖是生物医用材料领域研究的热点材料,具有广阔的发展前景。综述疝修补材料和以甲壳素和壳聚糖为代表的海洋生物材料的生物学特性及其在疝修补领域的研究进展,评价其作为疝修补材料的可行性,为海洋生物材料在疝修补领域的广泛应用提供新思路。     

几丁糖预防术后肠粘连疗效观察

[目的]观察几丁糖预防术后肠粘连的临床效果.[方法]243例胃肠道恶性肿瘤手术患者,随机分成治疗组和对照组.治疗组121例应用几丁糖预防术后肠粘连,对照组122例术后直接关腹.[结果]治疗组6例(4.96%)发生粘连性肠梗阻,对照组25例(20.49%)发生,差异有显著性(P<0.05).两组分别有8例和12例本院再手...     

Chitin-Methacrylate: Preparation,Characterization and Hydrogel Formation

Chitin-methacrylate (CM) was prepared by the reaction of methacrylic acid on chitin in 5% LiCl/DMAc in the presence of N,N’-dicyclocarbodiimide and dimethylaminopyridine. The resultant chitin-methacrylate product was isolated in 61% yield and was found to be readily water-soluble. The derivative was found to be a mixture of methacrylate and methacrylic-dimethylaminopyridine complex substituents at the C-6 position in approximately equal amounts. In order to evaluate the activity of the methacrylate double bond, a chitin-methacrylate water solution was photo-crosslinked in the presence of Irgacure 2959 photo-initiator to generate CM-hydrogel. The CM-hydrogel was evaluated for its biodegradability characteristics by enzymatic degradation with lysozyme solutions of varying concentrations. Completely water-soluble products were obtained within 48 h. In vitro cytotoxicity assays of the CM-hydrogel and its extract against three cell lines, NCTC clone 929, IMR-90 and MG-63, indicated the hydrogel was non-cytotoxic with cells able to adhere and proliferate well on the hydrogel.     

Glycol chitin/PAA hydrogel composite incorporated bio-functionalized PLGA microspheres intended for sustained release of anticancer drug through intratumoral injection

Abstract

A novel anti-hepatoma drug release hybrid system is prepared by using poly(acrylic acid) (PAA) and glycol chitin as substrate in combination with Paclitaxel (PTX)-loaded bio-biofunctionalized poly(lactic-co-glycolic acid) (PLGA) micro-particles, which is intended for cancer therapy through intratumoral injection. The rheological behavior of glycol chitin (7?wt%)/PAA illustrates that it has low gelling temperature (i.e. 17?°C at pH 7.56) which ensures that the formulation turns to gel at physiological condition. The gelling time of glycol chitin/PAA is 16?minutes at 25?°C and 3?minutes at 37?°C, which is convenient for doctors to inject the in-situ gel formulations into the tumor location of patient. The drug release behavior reveals that the system can dramatically postpone the drug release. The cell viability test indicates that the micro-particles with drug still have 62% inhibitory effect on hepatoma cells in the fourteenth day after combing with hydrogel. This system is a promising approach for cancer therapy through intratumoral injection of in-situ gel formulations to extend retention time at tumor sites.