Department of Chemical and Biological Engineering and School of Biomedical Engineering, Colorado State University, Fort Collins, CO 80523-1370, USA.
Biomacromolecules. 2010 Oct 11;11(10):2629-39. doi: 10.1021/bm1005799.
It is generally accepted that both surface chemistry and biochemical cues affect mesenchymal stem cell (MSC) proliferation and differentiation. Several growth factors that have strong influences on MSC behavior bind to glycosaminoglycans in interactions that affect their stability and their biochemical activity. The goal of this work was to develop polysaccharide-based polyelectrolyte multilayers (PEMs) to bind and stabilize growth factors for delivery to MSCs. Using the naturally derived polysaccharides chitosan and heparin, PEMs were constructed on gold-coated glass chips, tissue-culture polystyrene (TCPS), and titanium. PEM construction and basic fibroblast growth factor (FGF-2) adsorption to PEMs were evaluated by Fourier transform surface plasmon resonance, X-ray photoelectron spectroscopy, and polarization modulation infrared reflection absorption spectroscopy. The functional response of bone marrow-derived ovine MSCs to FGF-2 on PEM-coated TCPS and titanium was evaluated in vitro, in the presence and absence of adsorbed fibronectin. The effect of FGF-2 dose and presentation on MSC attachment and proliferation was evaluated using low-serum media, over four days. On PEM-coated TCPS, we found that FGF-2 adsorbed to heparin-terminated PEMs with adsorbed fibronectin induces greater cell density and a higher proliferation rate of MSCs than any of the other conditions tested, including delivery of the FGF-2 in solution, at an optimally mitogenic dose. Cell densities on day four were 1.8 times higher when FGF-2 was delivered by adsorption to the PEM than when FGF-2 was delivered in solution. This system represents a promising candidate for the development of surface coatings that can stabilize and potentiate the activity of growth factors for therapeutic applications. Interestingly, the same effects were not observed when FGF-2 was delivered by adsorption to PEMs on titanium. When the polysaccharide-based PEMs were formed on titanium, the proliferative response of ovine MSCs to adsorbed FGF-2 was not as strong as the response to FGF-2 delivered in solution.
人们普遍认为，表面化学和生化线索都会影响间充质干细胞（MSC）的增殖和分化。一些对 MSC 行为有强烈影响的生长因子与糖胺聚糖结合，这种相互作用会影响它们的稳定性和生化活性。本工作的目的是开发基于多糖的聚电解质多层膜（PEM），以结合和稳定生长因子，用于向 MSC 递药。使用天然衍生的多糖壳聚糖和肝素，在金涂覆的玻璃芯片、组织培养聚苯乙烯（TCPS）和钛上构建 PEM。通过傅里叶变换表面等离子体共振、X 射线光电子能谱和偏振调制红外反射吸收光谱评估 PEM 的构建和基本成纤维细胞生长因子（FGF-2）对 PEM 的吸附。在存在和不存在吸附纤连蛋白的情况下，在 PEM 涂覆的 TCPS 和钛上评估骨髓来源的绵羊 MSC 对 FGF-2 的体外功能反应。使用低血清培养基，在四天的时间内评估 FGF-2 剂量和呈现方式对 MSC 附着和增殖的影响。在 PEM 涂覆的 TCPS 上，我们发现，与吸附纤连蛋白的肝素末端 PEM 吸附的 FGF-2 比任何其他测试条件都能诱导更高的 MSC 细胞密度和更高的增殖率，包括以最佳有丝分裂剂量在溶液中递药。与溶液中递药相比，当 FGF-2 通过吸附递药到 PEM 时，第四天的细胞密度高 1.8 倍。该系统代表了一种有前途的候选物，用于开发表面涂层，该涂层可以稳定和增强治疗应用中生长因子的活性。有趣的是，当 FGF-2 通过吸附到钛上的 PEM 递药时，并没有观察到相同的效果。当基于多糖的 PEM 在钛上形成时，绵羊 MSC 对吸附的 FGF-2 的增殖反应不如溶液中递药的反应强烈。
