葡聚糖／壳聚糖水凝胶的制备及其作为生长因子载体的研究

合成并表征了砜基葡聚糖（Dex—vs）和巯基化壳聚糖（CS-SH），利用迈克尔加成反应，以巯基化壳聚糖为大分子交联剂，制备了葡聚糖／壳聚糖（Dex／CS）水凝胶。采用扫描电镜（SEM）考察了凝胶支架的形貌，并研究了其降解行为。研究发现，水凝胶的降解时间可由前驱物浓度以及砜基取代度来调控。细胞毒性研究表明该水凝胶具有良好的生物相容性。在此基础上，将其负载骨诱导生长因子人重组骨形态发生蛋白-2（rhBMP-2）后植入老鼠肌袋内，评价动物体内异位成骨的情况。通过新生异位骨的成骨量以及组织学评价结果表明，负载rhBMP-2的凝胶支架具有良好的异位成骨效果。本研究表明此类凝胶有望作为一种新型的可注射生长因子载体用于组织修复。

Preparation of Dextran/Chitosan Hydrogel and Study as the Carriers of Growth Factor

Dextran vinyl sulfone （Dex-VS） and mercapto chitosan （CS-SH） derivates were synthesized and character- ized in the study. In addition, CS-SH was selected as a kind of macromolecular crosslinking agent taking advantage of the Michael addition between - VS and - SH groups, thus generated dextran-based hydrogel network. Morphology of the hy- drogel scaffold was inspected through scanning electron microscope （SEM）. Various degradation behaviors under different conditions were investigated. The duration time can be regulated via both concentration of dextran precursors and degree of substitutions. Cellular biocompatibility of the hydrogel was confirmed through MTT assay. Based on the above results, the inductive growth factor, rhBMP-2, was loaded into the scaffold and implanted into mouse thigh muscles to investigate ec- topic bone formation. Mass of neo-bone was notably observed compared to control group, as well as the histological evalua- tions. Consequently, such kind of hydrogel might give promising application in tissue regeneration and delivery of growth factors.