Department of Bioengineering, University of Pennsylvania, 240 Skirkanich Hall, 210 S. 33rd St, Philadelphia, PA, 19104, USA.
Department of Chemistry, University of Maine, Orono, ME, 04469, USA.
Adv Healthc Mater. 2018 May;7(9):e1701199. doi: 10.1002/adhm.201701199. Epub 2018 Jan 23.
The transmembrane glycoprotein N-cadherin (NCad) mediates cell-cell interactions found during mesenchymal condensation and chondrogenesis. Here, NCad-derived peptides (i.e., HAV) are incorporated into hyaluronic acid (HA) hydrogels with encapsulated mesenchymal stem cells (MSCs). Since the dose and timing of NCad signaling are dynamic, HAV peptide presentation is tuned via alterations in peptide concentration and incorporation of an ADAM10-cleavable domain between the hydrogel and the HAV motif, respectively. HA hydrogels functionalized with HAV result in dose-dependent increases in early chondrogenesis of encapsulated MSCs and resultant cartilage matrix production. For example, type II collagen and glycosaminoglycan production increase ≈9- and 2-fold with the highest dose of HAV (i.e., 2 × 10 m), respectively, when compared to unmodified hydrogels, while incorporation of an efficient ADAM10-cleavable domain between the HAV peptide and hydrogel abolishes increases in chondrogenesis and matrix production. Treatment with a small-molecule ADAM10 inhibitor restores the functional effect of the HAV peptide, indicating that timing and duration of HAV peptide presentation is crucial for robust chondrogenesis. This study demonstrates a nuanced approach to the biofunctionalization of hydrogels to better emulate the complex cell microenvironment during embryogenesis toward stem-cell-based cartilage production.
跨膜糖蛋白 N-钙黏蛋白（NCad）介导间充质浓缩和软骨发生过程中发现的细胞-细胞相互作用。在这里，NCad 衍生肽（即 HAV）被包裹在间充质干细胞（MSCs）的透明质酸（HA）水凝胶中。由于 NCad 信号的剂量和时间是动态的，因此通过改变肽浓度和在水凝胶和 HAV 基序之间分别掺入 ADAM10 可切割结构域来调节 HAV 肽的呈现。用 HAV 功能化的 HA 水凝胶导致包封的 MSC 早期软骨发生呈剂量依赖性增加，并导致软骨基质的产生。例如，与未修饰的水凝胶相比，当 HAV 的最高剂量（即 2×10-6 m）时，II 型胶原蛋白和糖胺聚糖的产生分别增加了约 9 倍和 2 倍，而在 HAV 肽和水凝胶之间掺入有效的 ADAM10 可切割结构域会消除软骨发生和基质产生的增加。用小分子 ADAM10 抑制剂处理可恢复 HAV 肽的功能作用，表明 HAV 肽呈现的时间和持续时间对于健壮的软骨发生至关重要。这项研究展示了一种细微的方法来对水凝胶进行生物功能化，以更好地模拟胚胎发生过程中复杂的细胞微环境，从而实现基于干细胞的软骨生产。
