3D打印内部微通道的HBC-纳米纤维水凝胶支架用于增强软骨分化

我们首先制备了掺入PLGA电纺纳米纤维的HBC水凝胶（HBC-NF水凝胶），其模拟软骨ECM的微环境以促进人MSCs（hMSCs）的软骨形成。然后，我们在体外研究了HBC-NF水凝胶的物理化学性质和软骨分化诱导性。接下来，使用3D打印技术构建的PCL框架注入HBC-NF水凝胶，以获得与天然软骨类似的机械强度。同时，为了改善HBC-NF水凝胶中的营养和废物交换，采用了一种创新的方法来制造内部微通道。Pluronic F-127作为支持材料，与PCL共印刷，并在注射HBC-NF水凝胶后冲洗掉，以产生内部微通道（方案1）。在体内研究了PCL框架增强HBC-NF水凝胶支架的力学性能和hMSCs的软骨形成。我们设想，由此制造的3D复合材料构建体可以为hMSCs的生长和软骨分化提供仿生微环境，并提供必要的机械支持。

We first prepared HBC hydrogels incorporated with PLGA electrospun nanofibers (HBC-NF hydrogels), which mimic the microenvironment of cartilage extracellular matrix (ECM) to promote chondrogenesis of human mesenchymal stem cells (hMSCs). Subsequently, we investigated the physicochemical properties and chondrogenic differentiation-inducing capacity of HBC-NF hydrogels in vitro. Next, we infused HBC-NF hydrogels into a PCL framework fabricated via 3D printing technology to acquire mechanical strength similar to that of native cartilage. Meanwhile, to improve nutrient and waste exchange within the HBC-NF hydrogels, an innovative approach was adopted to fabricate internal microchannels. Pluronic F-127, as a supporting material, was co-printed with PCL, and then washed away after the injection of HBC-NF hydrogels to generate internal microchannels (Scheme 1). We then evaluated the mechanical performance of the PCL framework-reinforced HBC-NF hydrogel scaffold and the chondrogenesis of hMSCs in vivo. We envision that the as-fabricated 3D composite construct can provide a biomimetic microenvironment for the growth and chondrogenic differentiation of hMSCs, as well as the necessary mechanical support.