Micro-well texture printed into PEG hydrogels using the FILM nanomanufacturing process affects the behavior of preadipocytes

To date, biomaterial scaffolds for adipose tissue engineering have focused on macro- and upper micro-scale fabrication, biocompatibility, and biodegradation, but have failed to recapitulate the sub-micron dimensions of native extracellular matrix (ECM) and, therefore, have not optimized material-cell interactions. Here, we report the findings from a study investigating the effects of a quasi-mimetic sub-micron (< 1 mu m) surface texture on the qualitative behavior of preadipocytes (PAs). We found that PAs in contact with tread-like micro-well structures exhibit a different morphology relative to PAs seeded onto control smooth glass surfaces. Additionally, the micro-well topography induced isolated PAs to undergo adipogenesis, which usually occurs in the presence of aggregates of contact-inhibited PAs. The micro-well structures were printed into polyethylene glycol dimethacrylate (PEGDMA) using the recently reported nanomanufacturing process called Flash Imprint Lithography Using a Mask Aligner (FILM). FILM is a simple process that can be utilized to fabricate micro- and nanostructures in UV-curable materials (D.Y. Fozdar, W. Zhang, M. Palard, C.W. Patrick Jr., S.C. Chen, Flash Imprint Lithography Using A Mask Aligner (FILM): A Method for Printing Nanostructures in Photosensitive Hydrogels for Tissue Engineering. Nanotechnology 19, 2008). We demonstrate the utilization of the FILM process for a tissue engineering application for the first time. The micro-well topographical theme is characterized by contact angle and surface energy analysis and the results were compared with those for smooth glass and unpatterned PEGDMA surfaces. Based on our observations, we believe that the micro-well texture may ultimately be beneficial on implantable tissue scaffolds.