The aim of this investigation was to engineer metformin (MF)-loaded mesoporous silica nanospheres (MSNs)-laden gelatin methacryloyl (GelMA) photocrosslinkable hydrogels and test their effects on the mechanical properties, swelling ratio, drug release, cytocompatibility, and osteogenic differentiation of stem cells from human exfoliated deciduous teeth (SHEDs). As-received and carboxylated MSNs (MSNs-COOH) were characterized by scanning and transmission electron microscopies (SEM and TEM), as well as Fourier-transform infrared spectroscopy (FTIR) prior to hydrogel modification. MF-MSNs-COOH were obtained by loading MF into MSNs at a 1:1 mass ratio. Upon MSNs-COOH laden-hydrogels fabrication, the mechanical properties, swelling ratio and MF release were evaluated. SHEDs were seeded on the hydrogels and cytocompatibility was examined. The effects of the MF-MSNs-COOH/GelMA on the osteogenic differentiation of SHEDs were measured by ALP activity, Alizarin Red assay, and Real-time PCR. Statistics were performed using one-way ANOVA (α = 0.05). Morphological (SEM and TEM) analyses of pristine and carboxylated MSNs revealed a mean particle size of 200 nm and 218 nm, respectively. Importantly, an intrinsic nanoporous structure was noticed. Incorporation of MSNs-COOH at 1.5 mg/mL in GelMA led to the highest compressive modulus and swelling ratio. The addition of MSNs-COOH (up to 3 mg/mL) in GelMA did not impact cell viability. The presence of MF in MSNs-COOH/GelMA significantly promoted cell proliferation. Significant upregulation of osteogenic-related genes (except OCN) were seen for modified (MSNs-COOH and MF-MSNs-COOH) hydrogels when compared to GelMA. Altogether, the engineered MF-MSNs-COOH/GelMA shows great promise in CMF applications as an injectable, cell-free and bioactive therapeutics for bone regeneration.

本研究的目的是设计负载二甲双胍 (MF) 的介孔二氧化硅纳米球 (MSN) 负载明胶甲基丙烯酰 (GelMA) 光交联水凝胶，并测试它们对水凝胶的机械性能、溶胀率、药物释放、细胞相容性和成骨分化的影响。来自人类脱落乳牙（SHED）的干细胞。在水凝胶改性之前，通过扫描和透射电子显微镜（SEM 和 TEM）以及傅里叶变换红外光谱 (FTIR) 对收到的羧基化 MSN (MSNs-COOH) 进行表征。MF-MSNs-COOH是通过将MF以1:1的质量比负载到MSNs中得到的。在制备 MSNs-COOH 负载水凝胶后，评估了机械性能、溶胀比和 MF 释放。将 SHED 接种在水凝胶上并检查细胞相容性。通过 ALP 活性、茜素红测定和实时 PCR 测量 MF-MSNs-COOH/GelMA 对 SHED 成骨分化的影响。使用单向方差分析 (α = 0.05) 进行统计。原始和羧化 MSN 的形态（SEM 和 TEM）分析显示平均粒径分别为 200 nm 和 218 nm。重要的是，注意到了固有的纳米多孔结构。在 GelMA 中加入 1.5 mg/mL 的 MSNs-COOH 可获得最高的压缩模量和溶胀比。在 GelMA 中添加 MSNs-COOH（最高 3 mg/mL）不会影响细胞活力。MSNs-COOH/GelMA 中 MF 的存在显着促进细胞增殖。与 GelMA 相比，改性水凝胶（MSNs-COOH 和 MF-MSNs-COOH）的成骨相关基因（OCN 除外）显着上调。总而言之，工程化的 MF-MSNs-COOH/GelMA 作为一种可注射、无细胞和生物活性的骨再生疗法，在 CMF 应用中显示出巨大的前景。