A collagen based cryogel bioscaffold coated with nanostructured polydopamine as a platform for mesenchymal stem cell therapy

Abstract Cryo‐hydrogels (cryogels) are polymer hydrogels formed at sub‐zero temperatures. Bioscaffolds created from cryogels have interconnected macropores which allow for cell migration, tissue‐ingrowth, unhindered diffusion of solutes and mass transport of therapeutics. In this study, we developed collagen based cryogel bioscaffolds and coated them with polydopamine using a simple two‐step technique. Cryogel bioscaffolds were synthesized by collagen crosslinking at −20°C and exhibited a macroporous interconnected architecture with 75% ± 3% porosity. Two groups of pore sizes were observed: 300 ± 50 µm and 30 ± 10 µm in diameter. The addition of a polydopamine coating to cryogel bioscaffolds was confirmed using composition analysis. This resulted in a 41% ± 5% decrease in water uptake, 81% ± 10% decrease in swelling rate and 12% ± 3% decrease in their degree of dissolution (p < 0.05), with a 48% ± 2% increase in stiffness and 57% ± 5% increase in compressive strength (p < 0.05). Seeding adipose tissue‐derived mesenchymal stem cells (AD‐MSCs) into polydopamine coated‐cryogel bioscaffolds resulted in cells demonstrating a 52% ± 4% increase in viability and 33% ± 3% increase in proliferation when compared to AD‐MSCs seeded into uncoated‐cryogel bioscaffolds (p < 0.05). In summary, our novel polydopamine coated‐cryogel bioscaffold represents an efficient and low‐cost bioscaffold platform to support MSC therapies. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2213‐2228, 2018.