海藻酸钠/羽毛角蛋白复合纤维的制备与性能

采用酸碱法在鸭毛中提取羽毛角蛋白（FK）,通过正交实验研究了FK提取的最佳条件。将FK与海藻酸钠（SA）进行共混,制备SA/FK复合溶液,测试了复合溶液的流变性。通过湿法纺丝制备SA/FK复合纤维,研究了复合纤维的基本性能并表征了复合纤维分子间氢键作用。结果表明:在最佳提取条件下（提取温度为60.0℃,提取时间为120.00 min,碱浓度为2.00wt%）,FK产率最高为45.75%。SA/FK复合溶液的表观黏度随剪切速率的增加而减小,随FK含量的增加呈现先增后减的趋势。FK的加入使分子间氢键作用增强。SA/FK复合纤维的力学断裂强度能够达到1.96 cN/dtex。SA与FK的复合破坏了原有分子的晶体结构,SA/FK复合纤维分子结构是以非晶态存在。SA/FK复合纤维的表面具有均匀的沟槽结构。      

Improvement of side-effects and treatment on the experimental colitis in mice of a resin microcapsule-loading hydrocortisone sodium succinate

Context: Extensive or long-time use of corticosteroids often causes many toxic side-effects. The ion exchange resins and the coating material, Eudragit, can be used in combination to form a new oral delivery system to deliver corticosteroids.

Objectives: The resin microcapsule (DRM) composed by Amberlite 717 and Eudragit S100 was used to target hydrocortisone (HC) to the colon in order to improve its treatment effect on ulcerative colitis (UC) and reduce its toxic side-effects.

Methods: Hydrocortisone sodium succinate (HSS) was sequentially encapsulated in Amberlite 717 and Eudragit S100 to prepare the HSS-loaded resin microcapsule (HSS-DRM). The scanning electron microscopy (SEM) was employed to investigate the morphology and structure of HSS-DRM. The in vitro release and in vivo studies of pharmacokinetics and intestinal drug residues in rat were used to study the colon-targeting of HSS-DRM. The mouse induced by 2,4,6-trinitrobenzenesulfonic acid was used to study the treatment of HSS-DRM on experimental colitis.

Results: SEM study showed good morphology and structure of HSS-DRM. In the in vitro release study,?>?80% of HSS was released in the colon environment (pH 7.4). The in vivo studies showed good colon-targeting of HSS-DRM (T_max?=?0.97?h, C_max?=?118.28?µg/mL of HSS; T_max?=?2.16?h, C_max?=?64.47?µg/mL of HSS-DRM). Moreover, the HSS-DRM could reduce adverse reactions induced by HSS and had good therapeutic effects on the experimental colitis.

Conclusions: The resin microcapsule system has good colon-targeting and can be used in the development of colon-targeting preparations.     

Development and in vitro/in vivo evaluation of HPMC/chitosan gel containing simvastatin loaded self-assembled nanomicelles as a potent wound healing agent

The aim of this study was to develop hydroxypropyl methyl cellulose (HPMC)/chitosan gel containing polymeric micelles loaded with simvastatin (Sim) and evaluates its wound healing properties in rats. An irregular full factorial design was employed to evaluate the effects of various formulation variables including polymer/drug ratio, hydration temperature, hydration time, and organic solvent type on the physicochemical characteristics of pluronic F127-cholesterol nanomicelles prepared using the film hydration method. Among single studied factors, solvent type had the most impact on the amount of drug loading and zeta potential. Particle size and release efficiency was more affected by hydration temperature. The optimized formulation suggested by desirability of 93.5% was prepared using 1?mg of Sim, 10?mg of copolymer, dichloromethane as the organic solvent, hydration time of 45?min and hydration temperature of 25?°C. The release of the drug from nanomicelles was found to be biphasic and showed a rapid release in the first stage followed by a sustained release for 96?h. The gel-contained nanomicelles exhibited pseudo-plastic flow and more sustained drug release profile compared to nanomicelles. In excision wound model on normal rats, the wound closure of the group treated by Sim loaded micelles-gel was superior to other groups. Taken together, Sim loaded micelles-gel may represent a novel topical formulation for wound healing.