Brown Cody F C, Yan Jing, Han Tim Tian Y, Marecak Dale M, Amsden Brian G, Flynn Lauren E
Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario N6A 5C1, Canada.
Biomed Mater. 2015 Jul 30;10(4):045010. doi: 10.1088/1748-6041/10/4/045010.
An injectable composite scaffold incorporating decellularized adipose tissue (DAT) as a bioactive matrix within a hydrogel phase capable of in situ polymerization would be advantageous for adipose-derived stem cell (ASC) delivery in the filling of small or irregular soft tissue defects. Building on previous work, the current study investigates DAT milling methods and the effects of DAT particle size and cell seeding density on the response of human ASCs encapsulated in photo-cross-linkable methacrylated chondroitin sulphate (MCS)-DAT composite hydrogels. DAT particles were generated by milling lyophilized DAT and the particle size was controlled through the processing conditions with the goal of developing composite scaffolds with a tissue-specific 3D microenvironment tuned to enhance adipogenesis. ASC proliferation and adipogenic differentiation were assessed in vitro in scaffolds incorporating small (average diameter of 38 ± 6 μm) or large (average diameter of 278 ± 3 μm) DAT particles in comparison to MCS controls over a period of up to 21 d. Adipogenic differentiation was enhanced in the composites incorporating the smaller DAT particles and seeded at the higher density of 5 × 10(5) ASCs/scaffold, as measured by glycerol-3-phosphate dehydrogenase (GPDH) enzyme activity, semi-quantitative analysis of perilipin expression and oil red O staining of intracellular lipid accumulation. Overall, this study demonstrates that decellularized tissue particle size can impact stem cell differentiation through cell-cell and cell-matrix interactions, providing relevant insight towards the rational design of composite biomaterial scaffolds for adipose tissue engineering.
一种可注射的复合支架，其在能够原位聚合的水凝胶相中包含脱细胞脂肪组织（DAT）作为生物活性基质，这对于在填充小的或不规则的软组织缺损时递送脂肪来源干细胞（ASC）将是有利的。基于先前的工作，本研究调查了DAT研磨方法以及DAT粒径和细胞接种密度对封装在可光交联的甲基丙烯酸化硫酸软骨素（MCS）-DAT复合水凝胶中的人ASC反应的影响。通过研磨冻干的DAT产生DAT颗粒，并通过加工条件控制粒径，目的是开发具有组织特异性3D微环境的复合支架，以促进脂肪生成。与MCS对照相比，在长达21天的时间内，在包含小（平均直径38±6μm）或大（平均直径278±3μm）DAT颗粒的支架中体外评估ASC增殖和成脂分化。通过甘油-3-磷酸脱氢酶（GPDH）酶活性、脂联素表达的半定量分析和细胞内脂质积累的油红O染色测量，在包含较小DAT颗粒并以5×10⁵个ASC/支架的较高密度接种的复合材料中，成脂分化增强。总体而言，本研究表明，脱细胞组织粒径可通过细胞-细胞和细胞-基质相互作用影响干细胞分化，为脂肪组织工程复合生物材料支架的合理设计提供了相关见解。
