BioNano Laboratory EA 4203, Montpellier 1 University , Montpellier, France.
ACS Appl Mater Interfaces. 2014 Feb 12;6(3):1719-28. doi: 10.1021/am4046316. Epub 2014 Jan 28.
In regenerative medicine, stem-cell-based therapy often requires a scaffold to deliver cells and/or growth factors to the injured site. Porous silicon (pSi) is a promising biomaterial for tissue engineering as it is both nontoxic and bioresorbable. Moreover, surface modification can offer control over the degradation rate of pSi and can also promote cell adhesion. Dental pulp stem cells (DPSC) are pluripotent mesenchymal stem cells found within the teeth and constitute a readily source of stem cells. Thus, coupling the good proliferation and differentiation capacities of DPSC with the textural and chemical properties of the pSi substrates provides an interesting approach for therapeutic use. In this study, the behavior of human DPSC is analyzed on pSi substrates presenting pores of various sizes, 10 ± 2 nm, 36 ± 4 nm, and 1.0 ± 0.1 μm, and undergoing different chemical treatments, thermal oxidation, silanization with aminopropyltriethoxysilane (APTES), and hydrosilylation with undecenoic acid or semicarbazide. DPSC adhesion and proliferation were followed for up to 72 h by fluorescence microscopy, scanning electron microscopy (SEM), enzymatic activity assay, and BrdU assay for mitotic activity. Porous silicon with 36 nm pore size was found to offer the best adhesion and the fastest growth rate for DPSC compared to pSi comporting smaller pore size (10 nm) or larger pore size (1 μm), especially after silanization with APTES. Hydrosilylation with semicarbazide favored cell adhesion and proliferation, especially mitosis after cell adhesion, but such chemical modification has been found to led to a scaffold that is stable for only 24-48 h in culture medium. Thus, semicarbazide-treated pSi appeared to be an appropriate scaffold for stem cell adhesion and immediate in vivo transplantation, whereas APTES-treated pSi was found to be more suitable for long-term in vitro culture, for stem cell proliferation and differentiation.
在再生医学中，基于干细胞的治疗通常需要支架将细胞和/或生长因子递送到损伤部位。多孔硅（pSi）作为组织工程的一种有前途的生物材料，因为它既无毒又可生物降解。此外，表面修饰可以控制 pSi 的降解速率，还可以促进细胞黏附。牙髓干细胞（DPSC）是存在于牙齿内的多能间充质干细胞，是干细胞的一个易于获取的来源。因此，将 DPSC 的良好增殖和分化能力与 pSi 基质的结构和化学性质相结合，为治疗用途提供了一种有趣的方法。在这项研究中，分析了人类 DPSC 在具有不同孔径（10±2nm、36±4nm 和 1.0±0.1μm）和不同化学处理的 pSi 基质上的行为，这些处理包括热氧化、氨丙基三乙氧基硅烷（APTES）硅烷化和十一烯酸或氨基脲的硅氢化。通过荧光显微镜、扫描电子显微镜（SEM）、酶活性测定和 BrdU 测定有丝分裂活性，在长达 72 小时的时间内跟踪 DPSC 的黏附和增殖。与具有较小孔径（10nm）或较大孔径（1μm）的 pSi 相比，具有 36nm 孔径的多孔硅为 DPSC 提供了最佳的黏附和最快的生长速度，尤其是经过 APTES 硅烷化处理后。与半卡巴腙的硅氢化有利于细胞黏附和增殖，尤其是细胞黏附后的有丝分裂，但这种化学修饰导致支架在培养基中仅稳定 24-48 小时。因此，半卡巴腙处理的 pSi 似乎是一种适合干细胞黏附和立即体内移植的支架，而 APTES 处理的 pSi 更适合长期体外培养，用于干细胞增殖和分化。
