Advanced Centre for Tissue Engineering, Department of Biochemistry, University of Kerala, Kariavattom Campus, Thiruvananthapuram 695581, Kerala, India.
Division of Polymeric Medical Devices, Department of Medical Device Engineering, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum 695012, Kerala, India.
ACS Appl Bio Mater. 2023 May 15;6(5):1742-1754. doi: 10.1021/acsabm.2c00690. Epub 2023 Apr 26.
The central nervous system has limited regeneration potential. The multipotency of adipose-derived mesenchymal stem cells (ADMSC) makes them an ideal autologous cell source for the regeneration of neural tissues. However, the likelihood of their differentiation into unwanted cell lineages when transplanted into a hostile injury environment is a serious disadvantage. Transplanting predifferentiated cells via an injectable carrier may aid in site-specific delivery for better survival of cells. Here, we focus on identifying an appropriate injectable hydrogel system that favors stem/progenitor cell attachment and differentiation for neural tissue engineering. An injectable composition of the hydrogel, derived from alginate dialdehyde (ADA) and gelatin, was formulated for this purpose. This hydrogel promoted proliferation/differentiation of ADMSCs to neural progenitors, visualized from the generation of prominent neurospheres and stage-specific expression of a neural progenitor marker (nestin, day 4), an intermittent neuronal marker (β-III tub, day 5), and a mature neuronal marker (MAP-2, day 8) with neural branching and networking (>85%). The differentiated cells also expressed the functional marker synaptophysin. There was no negative impact on stem/progenitor cell survival (>95%) or differentiation (∼90%) as compared to two-dimensional (2D) culture. Addition of appropriate quantities of asiatic acid specific for neural niche supported cell growth and differentiation without affecting cell survival (>90%) and improved neural branching and elongation. Optimized interconnected porous hydrogel niche exhibited rapid gelation (3 min) and self-healing properties mimicking native neural tissue. Both ADA-gelatin hydrogel by itself and that incorporated with asiatic acid were found to support stem/neural progenitor cell growth and differentiation and have potential applications as antioxidants and growth promoters upon release at the cell transplantation site. In short, the matrix itself or incorporated with phytomoieties could serve as a potential minimally invasive injectable cell delivery vehicle for cell-based therapies of neural diseases.
中枢神经系统的再生能力有限。脂肪间充质干细胞（ADMSC）的多能性使其成为神经组织再生的理想自体细胞来源。然而，当将其移植到充满敌意的损伤环境中时，它们向不需要的细胞谱系分化的可能性是一个严重的缺点。通过可注射载体移植预分化细胞可能有助于特定部位的递送，从而提高细胞的存活率。在这里，我们专注于确定一种合适的可注射水凝胶系统，该系统有利于神经组织工程中干细胞/祖细胞的附着和分化。为此目的，配制了源自藻酸盐醛（ADA）和明胶的水凝胶的可注射组合物。这种水凝胶促进 ADMSC 向神经祖细胞的增殖/分化，从明显的神经球生成和神经祖细胞标记物（巢蛋白，第 4 天）、间歇性神经元标记物（β-III 微管，第 5 天）和成熟神经元标记物（MAP-2 ，第 8 天）的阶段性表达中可以看出，具有神经分支和网络（>85％）。分化的细胞还表达了功能性标记物突触小体蛋白。与二维（2D）培养相比，对干细胞/祖细胞的存活（>95％）或分化（∼90％）没有负面影响。添加适量的特定于神经巢的积雪草酸可支持细胞生长和分化，而不会影响细胞存活（>90％），并改善神经分支和伸长。优化的互连多孔水凝胶巢表现出快速凝胶化（3 分钟）和自我修复特性，模仿天然神经组织。ADA-明胶水凝胶本身及其与积雪草酸结合都被发现可以支持干细胞/神经祖细胞的生长和分化，并且在细胞移植部位释放时具有作为抗氧化剂和生长促进剂的潜在应用。简而言之，该基质本身或与植物化学物质结合可以用作神经疾病基于细胞的治疗的潜在微创可注射细胞递送载体。
