骨髓间充质细胞与速固化磷酸钙支架共培养的实验研究

[目的]观察人骨髓间充质干细胞在速固化磷酸钙骨水泥支架中的增殖和生长情况。[方法]将速固化壳聚糖-磷酸钙骨水泥支架材料预先成形。采用全骨髓法分离人骨髓间充质细胞并在体外对细胞进行培养和扩增。72h首次换液,细胞融合80%传代,取第3代细胞用于实验。将细胞与磷酸钙骨水泥支架复合培养,分别利用四甲基偶氮唑蓝MTT法及扫描电镜等检测细胞在材料中的增殖和生长情况。[结果]用酶标仪检测OD值提示共培养后,支架内的细胞数量逐渐增加。扫描电镜结果显示支架材料内部为多孔结构,孔内见有细胞生长,细胞表面可见分泌颗粒。[结论]速固化壳聚糖-磷酸钙骨水泥对人骨髓间充质干细胞有较好的细胞相容性,细胞可在材料内黏附和增殖,是理想的骨组织工程支架材料。     

脱乙酰化反应条件对壳聚糖性能的影响

本文研究了甲壳素在脱乙酰化反应时不同反应条件,如碱浓度、反应时间、反应温度和处理方法对壳聚糖性能,如分子量、脱乙酰化度的影响,探讨了分子主链降解反应与脱乙酰化反应之间的关系。结果表明:随着碱浓度和反应时间的增加,壳聚糖脱乙酰化度提高,而分子量降低;脱乙酰化越高,主链降解程度增加;反应温度升高,脱乙酰化反应速度加快;而采用短时重复多次反应的处理方法,则可增加壳聚糖的脱乙酰化度,并减少主链降解程度。     

新型壳聚糖对血浆胆红素和细胞因子吸附性能的体外筛选初步研究

目的观察各类新型吸附剂对重型肝炎患者血浆中的胆红素和细胞因子的吸附性能。方法第一步,收集第一组重型肝炎患者的血浆各3ml,以8种不同的吸附剂(1#～3#为致孔剂浓度分别为3%、1%、5%的壳聚糖,4#为胺基化壳聚糖,5#为苯乙烯/二乙烯苯聚合物,6#为后交连苯乙烯/二乙烯苯聚合物,7#为壳聚糖-苯乙烯/二乙烯苯聚合物,8#为壳聚糖-后交连苯乙烯/二乙烯苯聚合物)各1ml进行吸附,检测对胆红素的吸附能力,做吸附剂筛选实验和吸附实验。第二步,用以上筛选出吸附率较好的两种吸附剂各1ml对第二组患者血浆(各3ml)进行胆红素和细胞因子的吸附实验。结果第一步实验显示胺基壳聚糖(4#)和苯乙烯/二乙烯苯聚合物(5#)有较好的吸附效果,4#吸附剂对总胆红素(TBiL)、直接胆红素(DBiL)、间接胆红素(IBiL)的吸附率分别为50.5%±3.4%、57.0%±11.3%、39.0%±7.2%;5#分别为30.1%±2.5%、32.6%±3.0%、27.6%±2.9%。第二步实验显示4#胺基化壳聚糖吸附后血浆中TBiL、DBiL、IBiL、白细胞介素6(IL-6)和肿瘤坏死因子α(TNF-α)水平下降比5#明显,有统计学意义(P<0.001)。结论胺基化壳聚糖(4#)体外吸附重型肝炎患者血浆中胆红素、细胞因子效果有明显优势。     

Enteral Absorption of Insulin in Rats from Mucoadhesive Chitosan-Coated Liposomes

Purpose. The mucoadhesiveness of polymer-coated liposomes was evaluated to develop a novel drug carrier system for oral administration of poorly absorbed drugs such as peptide drugs. Methods. Multilamellar liposomes consisting of dipalmitoylphosphatidylcholine (DPPC) and dicetyl phosphate (DCP) (DPPC:DCP = 8:2 in molar ratio) were coated with chitosan (CS), polyvinyl alcohol having a long alkyl chain (PVA-R) and poly (acrylic acid) bearing a cholesteryl group. The adhesiveness of the resultant polymer-coated liposomes to the rat intestine was measured in vitro by a particle counting method with a Coulter counter. The CS-coated liposomes containing insulin were administered to normal rats and the blood glucose level was monitored. Results. The existence of polymer layers on the surface of liposomes was confirmed by measuring the zeta potential of liposomes. The CS-coated liposomes showed the highest mucoadhesiveness and the degree of adhesion was dependent on the amount of CS on the surface of the liposomes. The blood glucose level of rats was found to be significantly decreased after administration of the CS-coated liposomes containing insulin. The lowered glucose level was maintained for more than 12h after administration of the liposomal insulin, which suggested mucoadhesion of the CS-coated liposomes in the intestinal tract of the rats.     

肝素化胶原/壳聚糖多孔支架的制备及其血管化的研究

本研究旨在构建一种能快速血管化的人工真皮替代物。用冻干法制备了胶原／壳聚糖多孔支架，并对其进行肝素化，观察此支架的结构特征、亲水性、体外降解性和组织相容性，同时将血管生成素引入到此支架，对复合有血管生成素的肝素化支架的体内血管化进行了初步研究。结果表明，肝素化胶原／壳聚糖多孔支架具有合适的三维多孔结构、良好的吸水性和较理想的酶解稳定性，体内实验表明，此支架具有良好的组织相容性，血管生成素可加快支架的血管化。     

壳聚糖与硫酸软骨素共混膜性质的研究

以壳聚糖和硫酸软骨素按一定比例制备出共混膜，研究了膜片的透光性、含水量、渗透性、力学性质、表面结构、生物降解性、生物相容性等性质。结果表明该共混膜具有较好的透光性、通透性、生物降解性和生物相容性，膜表面较粗糙。以此共混膜为载体培养兔角膜基质细胞，发现细胞在此共混膜上生长良好。制备膜片随着加入CaSO4量的增加，膜的通透性也随之增加。     

Chitosan hydrogel as a drug delivery carrier to control angiogenesis

An aqueous solution of photocrosslinkable chitosan containing azide groups and lactose moieties (Az-CH-LA) incorporating paclitaxel formed an insoluble hydrogel within 30 s of ultraviolet light (UV) irradiation. The chitosan hydrogel showed strong potential for use as a new tissue adhesive in surgical applications and wound dressing. The fibroblast growth factor (FGF)-2 molecules retained in the chitosan hydrogel and in an injectable chitosan/IO₄-heparin hydrogel remain biologically active, and were gradually released from the hydrogels as they biodegraded in vivo. The controlled release of biologically active FGF-2 molecules from the hydrogels caused induction of angiogenesis and collateral circulation occurred in healing-impaired diabetic (db/db) mice and in the ischemic limbs of rats. Paclitaxel, which is an antitumor reagent, was also retained in the chitosan hydrogel and remained biologically active as it was released on degradation of the hydrogel in vivo. The chitosan hydrogels incorporating paclitaxel effectively inhibited tumor growth and angiogenesis in mice. The purpose of this review is to describe the effectiveness of chitosan hydrogel as a local drug delivery carrier for agents (e.g., FGF-2 and paclitaxel) to control angiogenesis. It is thus proposed that chitosan hydrogel may be a promising new local carrier for drugs such as FGF-2 and paclitaxel to control vascularization.     

乙二胺羟丙基壳聚糖固定化天门冬酰胺酶的研究

研制了新型壳聚糖胺基衍生物-乙二胺羟丙基壳聚糖（EDA-HPCS）,并将其用于固定天门冬酰胺酶,分别考察了甲醛活化载体和戊二醛活化载体对固定化酶活力的影响,结果表明,在适当的固定化条件下,甲醛活化EDA-HPCS的固定化酶活力约为30U/g载体,而戊二醛活化EDA-HPCS固定化酶活力约为16U/g载体。     

几丁糖预防屈肌腱粘连的临床效果

目的：观察几丁糖预防肌腱粘连的临床效果。方法：对Ⅱ区肌腱损伤４８例７２条肌腱断裂行一期修复,术中采用改良Ｋｅｓｓｌｅｒ法缝合肌腱,在肌腱鞘管内注入２％医用几丁糖０．５￣１．０ｍｌ,缝合皮肤。     

电化法研究壳聚糖树脂与游离酸的相互作用

利用电化学实验技术跟踪交联壳聚糖树脂吸附低浓度游离酸的行为,讨论了不同盐酸浓度和不同甲醇浓度两种因素对吸附的影响,并利用固液相互作用方程,求取吸附剂－吸附质相互作用能。实验结果表明,交联壳聚糖树脂吸附低浓度游离酸的过程是遵循单分子 机制进行的。