支撑喉镜下CO2激光及几丁糖局部涂布治疗喉狭窄

目的：探讨CO2激光辅以局部几丁糖涂布治疗各种类型喉狭窄的手术方法和疗效。方法：1999年1月-2002年1月在全麻支撑喉镜下共行CO2激光辅以局部几丁糖涂布治疗种类喉狭窄患者21例，其中先天性喉2例，不同原因前联合粘连狭窄13例，后联合璞形成3例，喉乳头状瘤多次手术后喉闭锁2例，甲状腺术后双侧声带外展麻痹行杓状软骨切除术后声门狭窄1例。结果：全部患者术后随访6-24个月，18例拔管保留发声功能；3例再狭窄，2例经再次手术后拔管，无误吸，发声较低沉嘶哑；另一例行喉裂开“T”形管扩张。结论：CO2激光手术 几丁糖局部涂布是一种治疗喉狭窄的有效方法，手术安全简便，可避免颈外进路手术，同时保留较好的发声功能。     

移植的神经干细胞在脑损伤区壳聚糖载体中的存活与分化

目的:探讨移植的NSCs在大鼠脑损伤区壳聚糖载体中的存活、分化情况及其对TBI大鼠认知功能的影响。方法:低温冷冻干燥法制备壳聚糖多孔支架。将从鼠胚前脑中分离的NSCs扩增、标记BrdU。Feeney法制备SD大鼠TBI模型,随机分为3组:损伤对照组清创后不做移植;NSCs 支架移植组行壳聚糖作载体的NSCs移植;NSCs 支架 NGF移植组行壳聚糖作载体的NSCs移植,并在其中加入NGF。术后1、2、3个月行避暗回避和跳台试验。脑切片行Nissl染色、BrdU与NF-200免疫荧光双标染色。结果:两移植组的认知功能在术后1、2、3个月较损伤对照组明显改善,含NGF的移植组改善更加显著。两移植组术后1、2、3个月在移植区均可见BrdU与NF-200免疫荧光双标细胞,含NGF移植组中的双标细胞数量多、胞体大、突起多且长。结论:大鼠TBI后移植的外源性NSCs可以在脑损伤区壳聚糖载体中长期存活并向神经元分化,可以改善大鼠的认知功能;NGF对其具有促进作用。     

可博利口服液澄清工艺研究

目的：研究可博利口服液的澄清工艺。方法：以两种不同工艺配制制剂,比较总固体物含量,并采用正交试验法,以冬虫夏草多糖含量及总固体物含量为指标,优选澄清工艺,再进行稳定性考察的比较。结果：壳聚糖澄清工艺的总固体物含量比原工艺高14.7%,优选的澄清工艺为药液温度50℃、药液浓度（g∶ml）=1∶4、1%壳聚糖的用量为3%（W/W）。结论：本实验简化了壳聚糖澄清工艺,使有效成分的总保留量得到提高,且制剂稳定。     

几丁糖对不同来源成纤维细胞生物学特性的影响

目的　探讨医用几丁糖 (以下简称几丁糖 )对病理性瘢痕成纤维细胞生物学活性的作用。方法　以瘢痕疙瘩及增生性瘢痕成纤维细胞为研究对象 ,正常皮肤成纤维细胞为对照 ,用组织块法进行不同标本成纤维细胞体外培养。分别观测不同浓度的几丁糖作用后 ,不同来源成纤维细胞吸光度A、形态结构、合成及分泌胶原的量以及细胞因子TGF β1 、b FGF、IL 8等的变化。结果　几丁糖对不同来源成纤维细胞增殖及胶原、TGF β1 、b FGF、等的分泌均呈剂量依赖性抑制 ,对IL 8则促进 ;且对各组的影响差异无显著性意义。结论　几丁糖可以抑制瘢痕疙瘩和增生性瘢痕成纤维细胞的生长、增殖、合成及分泌胶原功能 ,有望在病理性瘢痕的防治中发挥重要作用。     

Study on biocompatibility of complexes of collagen-chitosan-sodium hyaluronate and cornea

In this study we investigated the biocompatibility of collagen-chitosan-sodium hyaluronate (Col-Chi-NaHA) complexes and cornea tissue, and the feasibility of Col-Chi-NaHA complexes as substrates for cultivating rabbit corneal cells. Different components of Col-Chi-NaHA complexes were prepared and tested. A circular complex film with a diameter of 6 mm was inserted into rabbit stomal pocket and traced for a period of 5 months. Clinical examination was made. Rabbit limbal corneal epithelial cells, corneal endothelial cells, and keratocytes were cultured primarily on complexes. Phase contrast microscope examination was made daily. Histological, immunohistochemical, and scanning electron microscopic examinations were carried out. The complexes of 20% collagen, 10% chitosan, and 0.5% sodium hyaluronate showed rather weak corneal edema and other responses. The degradation of materials was obvious after 5 months. Corneas were transparent and translucent. Cells seeded on Col-Chi-NaHA were allowed to proliferate and partly form confluent monolayer after 9 days in culture. Cultured cells were well attached to the complexes of 20% collagen, 10% chitosan, and 0.5% sodium hyaluronate, or 10% chitosan and 0.5% sodium hyaluronate. The results showed that Col-Chi-NaHA complexes had good biocompatibility with cornea. The complexes can degrade and be absorbed in cornea. Col-Chi-NaHA complex may be a suitable substrate for cultivating corneal cells and a feasible material as a scaffold of tissue-engineered cornea.     

Gamma scintigraphic evaluation of film-coated tablets intended for colonic or biphasic release

The gastrointestinal transit and in vivo drug release behaviour of a film-coated tablet formulation was investigated in five healthy human subjects using the technique of gamma scintigraphy. The film coating system consisted of a mixture of pectin, chitosan and HPMC in a ratio of 6:1:0.37 applied to 750 mg cores at a coat weight gain of 9%. The estimated mean values of the gastric emptying time (62±17 min), small intestinal transit time (219±53 min), ileocaecal junction lag time (79±30 min) and the colon arrival time (345±33 min), were similar to published values for the transit of similar sized tablets in humans. The amount of radioactive tracer released from the labelled tablets was minimal when the tablets were in the stomach and the small intestine. There was increased release of radioactivity when the tablets were in the colon due to increased degradation of the film coatings by pectinolytic enzymes resident in the colon. The pectin/chitosan/HPMC film coating system thus acts as a colonic delivery system.     

Chitosan Nanoparticles as New Ocular Drug Delivery Systems: in Vitro Stability,in Vivo Fate,and Cellular Toxicity

PURPOSE: To assess the potential of chitosan (CS) nanoparticles for ocular drug delivery by investigating their interaction with the ocular mucosa in vivo and also their toxicity in conjunctival cell cultures. METHODS: Fluorescent (CS-fl) nanoparticles were prepared by ionotropic gelation. The stability of the particles in the presence of lysozyme was investigated by determining the size and their interaction with mucin, by measuring the viscosity of the mucin dispersion. The in vivo interaction of CS-fl nanoparticles with the rabbit cornea and conjunctiva was analyzed by spectrofluorimetry and confocal microscopy. Their potential toxicity was assessed in a human conjunctival cell line by determining cell survival and viability. RESULTS: CS-fl nanoparticles were stable upon incubation with lysozyme and did not affect the viscosity of a mucin dispersion. In vivo studies showed that the amounts of CS-fl in cornea and conjunctiva were significantly higher for CS-fl nanoparticles than for a control CS-fl solution, these amounts being fairly constant for up to 24 h. Confocal studies suggest that nanoparticles penetrate into the corneal and conjunctival epithelia. Cell survival at 24 h after incubation with CS nanoparticles was high and the viability of the recovered cells was near 100%. CONCLUSIONS: CS nanoparticles are promising vehicles for ocular drug delivery.     

Synthesis, characterization and evaluation of IPN hydrogels for antibiotic release

We prepared new ternary interpenetrating polymeric networks (IPN) systems containing chitosan, poly(N-vinylpyrrolidone) and poly(acrylamide) polymers. IPNs were synthesized by radical polymerization of acrylamide monomers in presence of glutaraldehyde (G) and N,N'-methylenebisacrylamide as crosslinkers and the other polymers. These IPNs were named as C-P-A. Glutaraldehyde were used in different concentration to control the network porous of IPNs. Spectroscopic and thermal analyses of these cylindrical shaped IPNs were made with fourier transform infrared spectroscopy analysis, thermogravimetric analysis, and thermomechanical analysis. Swelling studies of IPNs were carried out at pH 1.1 and pH 7.4 at 37°C. The swelling and diffusion parameters of IPNs in these solutions were calculated. Amoxicillin as a bioactive species was entrapped to the IPNs during synthesis. In vitro release kinetics of IPNs were investigated. The experimental data of swelling and release studies suggest clearly that the swelling and release process obeys second-order kinetics. The release of the entrapped bioactive species from IPNs depends on the degree of crosslinking of the polymer and pH of the medium at body temperature. We observed that amoxicillin release at pH 1.1 was higher than at pH 7.4. As a result, IPNs-based chitosan with different cross-linker concentration could be promising candidates for formulation in oral gastrointestinal delivery systems.     

Microspheres for colonic delivery of ketoprofen-hydroxypropyl-β-cyclodextrin complex

A new multiparticulate system, with the potential for site-specific delivery to the colon, has been developed using ketoprofen as model drug. The system simultaneously exploits cyclodextrin complexation, to improve drug solubility, and vectorization in microspheres (MS) based on Ca-pectinate and chitosan. The effect of complexation with hydroxypropyl-β-cyclodextrin (HPβCyd) and of chitosan presence on drug entrapment efficiency and release properties, as well on the drug permeation rate across Caco-2 cells has been investigated. Solid-state interactions between the components have been investigated by FTIR spectroscopy, differential scanning calorimetry and X-ray powder diffractometry. The morphology of MS was examined by scanning electron microscopy. Release studies revealed a different behaviour for MS containing drug alone or as complex: drug alone was released faster than in the presence of cyclodextrin from MS without chitosan, due to a reservoir effect. The opposite was found for MS containing chitosan, due to a competition effect between polymer and drug for the cyclodextrin. Cytotoxicity tests demonstrated the safety of these formulations. Permeation studies showed an increased permeation of the drug formulated as MS, particularly marked when it was used as complex, thus revealing an enhancing power of both cyclodextrin and chitosan with a synergistic effect in improving drug permeation.     

氧氟沙星壳聚糖滴眼液的研制

增强氧氟沙星疗效和降低其不良反应。方法：以壳聚糖为辅料,研制氧氟沙星壳聚糖滴眼液。结果：此制备工艺可行,内在质量稳定。采用紫外分光光度法测定该品含量．方法简便、准确．平均回收率９９．７５％,ＲＳＤ＝０．３４％。结论：该品符合有关质量要求,可用于临床。