INSERM U 1148, Laboratory of Vascular Translational Science; X. Bichat Hospital, University Paris Diderot, 46 rue H. Huchard, 75018, Paris, France.
Institut Galilée, University Paris 13, 99 av JB Clément, 93430, Villetaneuse, France.
J Mater Sci Mater Med. 2018 May 29;29(6):77. doi: 10.1007/s10856-018-6085-x.
Hydrogels are very promising for tissue engineering as they provide scaffolds and a suitable microenvironment to control cell behavior and tissue regeneration. We used a patented method to obtain beads of pullulan/dextran cross-linked with sodium trimetaphosphate (STMP), that were already described for in vivo bone repair. The aim of this study was to provide a comparative analysis of microbeads made of polysaccharides prepared using three different STMP feeding ratio of 1.5, 2.25 or 3 % w/w. The morphology, swelling and biodegradability of these structures were assessed. Mesenchymal stem cells were also seeded to evaluate the cell organization onto the beads. We found that the amount of phosphorus resulting from the cross-linking was proportional to the introduced STMP concentration. An increase of cross-linking decreased the in vitro enzymatic degradability, and also decreased the swelling in PBS or water. The microstructures observed by SEM and confocal microscopy indicated that homogeneous spherical microbeads were obtained, except for the lower cross-linking ratio where the shapes were altered. Beads hydrated in PBS exhibited a mean diameter ranging from 400 to 550 µm with the decrease of STMP ratio. Cells adhered to the surface of microbeads even in the absence of protein coating. Cell viability studies revealed an increase in cell numbers over two weeks for the highest cross-linked beads, whereas the two lowest STMP concentrations induced a decrease of cell viability. Overall, this study demonstrated that pullulan/dextran hydrogels can be designed as microbeads with adjustable physicochemical and biological properties to fulfill requirements for tissue engineering approaches.
水凝胶在组织工程中很有前途，因为它们提供支架和合适的微环境来控制细胞行为和组织再生。我们使用了一种专利方法来获得用三聚磷酸钠（STMP）交联的普鲁兰/葡聚糖珠，这些珠已经被描述用于体内骨修复。本研究的目的是提供使用三种不同 STMP 喂养比例（1.5、2.25 或 3%w/w）制备的多糖微珠的比较分析。评估了这些结构的形态、溶胀和生物降解性。还将间充质干细胞接种到珠上，以评估细胞在珠上的组织情况。我们发现，交联产生的磷量与引入的 STMP 浓度成正比。交联度的增加降低了体外酶降解性，也降低了在 PBS 或水中的溶胀性。SEM 和共聚焦显微镜观察到的微观结构表明，除了交联率较低的情况外，得到了均匀的球形微珠。在 PBS 中水合的珠表现出 400 到 550μm 的平均直径，随着 STMP 比例的降低而降低。即使没有蛋白质涂层，细胞也能黏附在微珠的表面。细胞活力研究表明，对于交联度最高的珠，细胞数量在两周内增加，而两个最低的 STMP 浓度则降低了细胞活力。总的来说，这项研究表明，普鲁兰/葡聚糖水凝胶可以设计为具有可调节的物理化学和生物学特性的微珠，以满足组织工程方法的要求。
