Injectable hydrogels have emerged as promising biomaterials for tissue engineering applications. The goal of this study was to evaluate the potential of a pH-responsive chitosan-hydroxyapatite hydrogel to be used as a three-dimensional support for encapsulated mesenchymal stem cells (MSCs) osteogenic differentiation. In vitro enzymatic degradation of the hydrogel, during 28 days of incubation, in simulated physiological condiditons, was characterized by swelling measurements, molecular weight determination and SEM analysis of hydrogel microstructure. Osteogenic differentiation of encapsulated MSCs was confirmed by osteogenic Runx2, collagen type I and osteocalcin immunostaining and alkaline phosphatase quantification. The deposition of late osteogenic markers (calcium phosphates) detected by Alizarin red and von Kossa staining indicated an extracellular matrix mineralization.

可注射的水凝胶已经成为有希望的用于组织工程应用的生物材料。这项研究的目的是评估pH响应的壳聚糖-羟基磷灰石水凝胶作为封装的间充质干细胞（MSCs）成骨分化的三维支持物的潜力。体外在模拟的生理条件下孵育28天后，通过溶胀测量，分子量测定和水凝胶微观结构的SEM分析来表征水凝胶的酶促降解。成骨的Runx2，I型胶原蛋白和骨钙素的免疫染色以及碱性磷酸酶的定量结果证实了包埋的MSC的成骨分化。通过茜素红和von Kossa染色检测到的晚期成骨标记物（磷酸钙）的沉积表明细胞外基质矿化。