透明质酸微阵列结构的构建及其生物相容性研究

Fabrication of Hyaluronic Acid-Based Micropatterning and Investigation of Its Biocompatibility

植入材料表面的微结构在骨修复和组织再生中至关重要,而微阵列结构的可控制备是影响细胞尤其是骨间充质干细胞(BMSCs)生物学行为的关键因素之一。制备微阵列结构的材料通常降解性较差、生物活性不足。本文选用可降解高分子透明质酸(HA)为原材料,与己二酸二酰肼(ADH)和N′-(乙基亚胺基亚甲基)-N,N-二甲基-1,3-丙二胺(EDCI)交联成膜。随着ADH和EDCI的质量分数分别由8.3%增加到16.7%,薄膜交联程度越来越高,体积膨胀越来越小,薄膜的降解速率越来越慢。结合软光刻技术和溶剂挥发法,成功制备了一系列表面具有微阵列孔洞结构的HA薄膜(孔径分别为32、96、128、320μm)。研究结果表明:与平滑的HA凝胶薄膜相比,孔径较大(96、320μm)、排布较稀疏的表面结构对大鼠骨间充质干细胞(rBMSCs)的增殖没有显著影响,而孔径较小(32μm)、排布较密集的表面结构可以明显地促进rBMSCs的增殖及成骨活性。

The microstructure on the implants is essential for bone repairing and tissue regeneration.Especially,controllable preparation of well-defined micropattern is one of the key factors to regulate the biological fate of bone mesenchymal stem cells(BMSCs).Usually,the micropatterns are made of materials with limited degradability and poor bioactivity.In order to meet the needs for bone repairing and take the special structural and physiochemical properties of biomedical implants into account,the degradable hyaluronic acid(HA)was cross-linked with N′-(ethyliminomethylidene)-N,N-dimethyl-1,3-propylene diamine(EDCI)and adipic acid dihydrazide(ADH).Then,the HA microwell patterns were fabricated by soft-lithography technique.By turning the mass fraction of ADH and EDCI from 8.3%to 16.7%respectively,the effects of contents on the microstructure,swelling properties,degradation behavior,and compatibility of HA films were evaluated by a series of characterization methods.The experimental results showed that as the mass fraction of ADH and EDCI increased,the crosslinking degree of the film increased,and the swelling variation of gel became smaller.HA films with high mass fraction of ADH and EDCI showed a slower degradation behavior.A series of HA films with micro-array pore structure(pore diameter of 32,96,128,320μm respectively)were successfully fabricated by combining soft lithography and solvent evaporation.When co-culture with rBMSCs in vitro,the results showed that the larger micron wells(96,320μm)with sparse distribution presented no significant effect on the proliferation of rat bone mesenchymal stem cells(rBMSCs)compared to the smooth HA gel film,while the small micron wells(32μm)with compact distribution can significantly promote the proliferation and osteogenic activity of rBMSCs.