INSERM U1026, Bioingénierie tissulaire, 146 rue Léo Saignat, 33076 Bordeaux, France.
Université de Bordeaux, Bioingénierie tissulaire, 146 rue Léo Saignat, 33076 Bordeaux, France.
Biofabrication. 2022 Jan 24;14(2). doi: 10.1088/1758-5090/ac40ed.
Fibroblasts and myofibroblasts play a central role in skin homeostasis through dermal organization and maintenance. Nonetheless, the dynamic interactions between (myo)fibroblasts and the extracellular matrix (ECM) remain poorly exploited in skin repair strategies. Indeed, there is still an unmet need for soft tissue models allowing to study the spatial-temporal remodeling properties of (myo)fibroblasts., wound healing studies in animals are limited by species specificity., most models rely on collagen gels reorganized by randomly distributed fibroblasts. But biofabrication technologies have significantly evolved over the past ten years. High-resolution bioprinting now allows to investigate various cellular micropatterns and the emergent tissue organizations over time. In order to harness the full dynamic properties of cells and active biomaterials, it is essential to consider 'time' as the 4th dimension in soft tissue design. Following this 4D bioprinting approach, we aimed to develop a novel model that could replicate fibroblast dynamic remodeling. For this purpose, (myo)fibroblasts were patterned on collagen gels with laser-assisted bioprinting (LAB) to study the generated matrix deformations and reorganizations. First, distinct populations, mainly composed of fibroblasts or myofibroblasts, were establishedto account for the variety of fibroblastic remodeling properties. Then, LAB was used to organize both populations on collagen gels in even isotropic patterns with high resolution, high density and high viability. With maturation, bioprinted patterns of fibroblasts and myofibroblasts reorganized into dispersed or aggregated cells, respectively. Stress-release contraction assays revealed that these phenotype-specific pattern maturations were associated with distinct lattice tension states. The two populations were then patterned in anisotropic rows in order to direct the cell-generated deformations and to orient global matrix remodeling. Only maturation of anisotropic fibroblast patterns, but not myofibroblasts, resulted in collagen anisotropic reorganizations both at tissue-scale, with lattice contraction, and at microscale, with embedded microbead displacements. Following a 4D bioprinting approach, LAB patterning enabled to elicit and orient the dynamic matrix remodeling mechanisms of distinct fibroblastic populations and organizations on collagen. For future studies, this method provides a new versatile tool to investigatedermal organizations and properties, processes of remodeling in healing, and new treatment opportunities.
成纤维细胞和肌成纤维细胞通过真皮组织和维持在皮肤稳态中发挥核心作用。尽管如此，（肌）成纤维细胞与细胞外基质（ECM）之间的动态相互作用在皮肤修复策略中仍未得到充分利用。事实上，仍然需要软组织模型来研究（肌）成纤维细胞的时空重塑特性，但动物的伤口愈合研究受到物种特异性的限制。大多数模型依赖于随机分布的成纤维细胞重新组织的胶原凝胶。但是，生物制造技术在过去十年中得到了显著发展。高分辨率生物打印现在可以研究各种细胞微图案和随时间出现的组织组织。为了利用细胞和活性生物材料的全部动态特性，必须将“时间”视为软组织设计的第四个维度。遵循这种 4D 生物打印方法，我们旨在开发一种新的模型，该模型可以复制成纤维细胞的动态重塑。为此，使用激光辅助生物打印（LAB）在胶原凝胶上对（肌）成纤维细胞进行图案化，以研究产生的基质变形和重组。首先，建立了主要由成纤维细胞或肌成纤维细胞组成的不同群体，以说明成纤维细胞重塑特性的多样性。然后，LAB 用于以高分辨率、高密度和高存活率在胶原凝胶上均匀各向同性地组织这两种群体。随着成熟，成纤维细胞和肌成纤维细胞的生物打印图案分别重新组织成分散或聚集的细胞。应变速率收缩测定表明，这些表型特异性图案成熟与不同的晶格张力状态有关。然后将两种群体以各向异性行进行图案化，以引导细胞产生的变形并使全局基质重塑定向。只有各向异性成纤维细胞图案的成熟，而不是肌成纤维细胞的成熟，导致组织尺度上的胶原各向异性重组，晶格收缩，以及微尺度上的嵌入微珠位移。通过 4D 生物打印方法，LAB 图案化能够引发和定向不同成纤维细胞群体和组织在胶原上的动态基质重塑机制。对于未来的研究，这种方法提供了一种新的多功能工具，可以研究皮肤组织和特性、愈合过程中的重塑过程以及新的治疗机会。
