Kanokova Denisa, Matejka Roman, Zaloudkova Margit, Zigmond Jan, Supova Monika, Matejkova Jana
Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University in Prague, Sitna 3105, 272 01 Kladno, Czech Republic.
Department of Composites and Carbon Materials, Institute of Rock Structure and Mechanics, Czech Academy of Sciences, 182 09 Prague, Czech Republic.
Gels. 2024 May 5;10(5):316. doi: 10.3390/gels10050316.
The bioprinting of high-concentrated collagen bioinks is a promising technology for tissue engineering and regenerative medicine. Collagen is a widely used biomaterial for bioprinting because of its natural abundance in the extracellular matrix of many tissues and its biocompatibility. High-concentrated collagen hydrogels have shown great potential in tissue engineering due to their favorable mechanical and structural properties. However, achieving high cell proliferation rates within these hydrogels remains a challenge. In static cultivation, the volume of the culture medium is changed once every few days. Thus, perfect perfusion is not achieved due to the relative increase in metabolic concentration and no medium flow. Therefore, in our work, we developed a culture system in which printed collagen bioinks (collagen concentration in hydrogels of 20 and 30 mg/mL with a final concentration of 10 and 15 mg/mL in bioink) where samples flow freely in the culture medium, thus enhancing the elimination of nutrients and metabolites of cells. Cell viability, morphology, and metabolic activity (MTT tests) were analyzed on collagen hydrogels with a collagen concentration of 20 and 30 mg/mL in static culture groups without medium exchange and with active medium perfusion; the influence of pure growth culture medium and smooth muscle cells differentiation medium was next investigated. Collagen isolated from porcine skins was used; every batch was titrated to optimize the pH of the resulting collagen to minimize the difference in production batches and, therefore, the results. Active medium perfusion significantly improved cell viability and activity in the high-concentrated gel, which, to date, is the most limiting factor for using these hydrogels. In addition, based on SEM images and geometry analysis, the cells remodel collagen material to their extracellular matrix.
高浓度胶原蛋白生物墨水的生物打印是一种在组织工程和再生医学领域很有前景的技术。胶原蛋白是生物打印中广泛使用的生物材料，因为它在许多组织的细胞外基质中天然丰富且具有生物相容性。高浓度胶原蛋白水凝胶因其良好的机械和结构性能，在组织工程中显示出巨大潜力。然而，在这些水凝胶中实现高细胞增殖率仍然是一个挑战。在静态培养中，培养基体积每隔几天更换一次。因此，由于代谢物浓度相对增加且无培养基流动，无法实现完美的灌注。所以，在我们的工作中，我们开发了一种培养系统，其中打印的胶原蛋白生物墨水（水凝胶中胶原蛋白浓度为20和30mg/mL，生物墨水中最终浓度为10和15mg/mL），样本在培养基中自由流动，从而增强细胞营养物质和代谢物的清除。在不更换培养基的静态培养组以及有活性培养基灌注的情况下，对胶原蛋白浓度为20和30mg/mL的胶原蛋白水凝胶进行了细胞活力、形态和代谢活性（MTT试验）分析；接下来研究了纯生长培养基和平滑肌细胞分化培养基的影响。使用从猪皮中分离的胶原蛋白；每一批都进行滴定以优化所得胶原蛋白的pH值，以尽量减少生产批次差异，进而减少结果差异。活性培养基灌注显著提高了高浓度凝胶中的细胞活力和活性，而这是迄今为止使用这些水凝胶的最限制因素。此外，基于扫描电子显微镜图像和几何分析，细胞将胶原蛋白材料重塑为其细胞外基质。
