Dorthé Erik W, Williams Austin B, Grogan Shawn P, D'Lima Darryl D
Department of Orthopaedics, Shiley Center for Orthopaedic Research and Education, Scripps Health, San Diego, CA, United States.
Intitute for Biomedical Sciences, San Diego, CA, United States.
Front Bioeng Biotechnol. 2022 Feb 2;10:810705. doi: 10.3389/fbioe.2022.810705. eCollection 2022.
Nanofibrous scaffolds fabricated via electrospinning have been proposed for meniscus tissue regeneration. However, the electrospinning process is slow, and can only generate scaffolds of limited thickness with densely packed fibers, which limits cell distribution within the scaffold. In this study, we explored whether pneumatospinning could produce thicker collagen type I fibrous scaffolds with higher porosity, that can support cell infiltration and neo-fibrocartilage tissue formation for meniscus tissue engineering. We pneumatospun scaffolds with solutions of collagen type I with thicknesses of approximately 1 mm in 2 h. Scanning electron microscopy revealed a mix of fiber sizes with diameters ranging from 1 to 30 µm. The collagen scaffold porosity was approximately 48% with pores ranging from 7.4 to 100.7 µm. The elastic modulus of glutaraldehyde crosslinked collagen scaffolds was approximately 45 MPa, when dry, which reduced after hydration to 0.1 MPa. Mesenchymal stem cells obtained from the infrapatellar fat pad were seeded in the scaffold with high viability (>70%). Scaffolds seeded with adipose-derived stem cells and cultured for 3 weeks exhibited a fibrocartilage meniscus-like phenotype (expressing COL1A1, COL2A1 and COMP). implantation in healthy bovine and arthritic human meniscal explants resulted in the development of fibrocartilage-like neotissues that integrated with the host tissue with deposition of glycosaminoglycans and collagens type I and II. Our proof-of-concept study indicates that pneumatospinning is a promising approach to produce thicker biomimetic scaffolds more efficiently that electrospinning, and with a porosity that supports cell growth and neo-tissue formation using a clinically relevant cell source.
通过静电纺丝制备的纳米纤维支架已被用于半月板组织再生。然而，静电纺丝过程缓慢，且只能生成纤维紧密堆积、厚度有限的支架，这限制了细胞在支架内的分布。在本研究中，我们探究了气动纺丝是否能制备出具有更高孔隙率的更厚的I型胶原纤维支架，以支持细胞浸润和新纤维软骨组织形成，用于半月板组织工程。我们用I型胶原溶液在2小时内气动纺出了厚度约为1毫米的支架。扫描电子显微镜显示纤维尺寸混合，直径范围为1至30微米。胶原支架孔隙率约为48%，孔径范围为7.4至100.7微米。戊二醛交联的胶原支架干燥时的弹性模量约为45兆帕，水合后降至0.1兆帕。从髌下脂肪垫获得的间充质干细胞以高活力（>70%）接种到支架中。接种脂肪来源干细胞并培养3周的支架呈现出纤维软骨样半月板表型（表达COL1A1、COL2A1和COMP）。植入健康牛和患有关节炎的人半月板外植体后，形成了纤维软骨样新组织，该新组织与宿主组织整合，并沉积了糖胺聚糖以及I型和II型胶原。我们的概念验证研究表明，气动纺丝是一种比静电纺丝更有前景的方法，能够更高效地制备更厚的仿生支架，其孔隙率支持使用临床相关细胞来源进行细胞生长和新组织形成。
