@article {18960, title = {Enzymatically cross-linked silk fibroin scaffolds support human adipose-derived stem cells chondrogenesis for cartilage tissue engineering applications}, booktitle = {Chem2Nature}, year = {2016}, month = {2016-11-21 00:00:00}, address = {Guimar{\~a}es, Portugal}, abstract = {

Several processing technologies can be combined to produce scaffolds with superior performance for tissue engineering (TE) applications. Different biodegradable materials have been proposed as matrices for cartilage scaffolding[1].\  The natural polymer silk fibroin (SF) has been attractive for developing innovative scaffolds for cartilage TE applications[2]. Hydrogels have also been extensively applied for different cartilage repair strategies, presenting structural similarity to the natural extracellular matrix of cartilage, high elasticity and resistance to compression forces[3]. Tyrosine groups presented by SF can be used to produce hydrogels with controlled gelation properties, using for crosslinking an horseradish peroxidase (HRP) catalyzed reaction[4][5]. This work aims to develop novel SF-based scaffolds and evaluate their in vitro ability to support human adipose-derived stem cells (hASCs) adhesion, proliferation and chondrogenic differentiation. SF-based scaffolds were derived from high-concentrated SF(16wt\%) enzymatically cross-linked by a HRP/H2O2 complex and combined with salt-leaching and freeze-drying methodologies to prepare interconnected macro-/micro-porous structures with specific features regarding biodegradation and mechanical properties. Human ASCs were cultured over 28 days in basal and chondrogenic conditions. Cell behaviour in the presence of the porous structures was evaluated through different quantitative (DNA and GAGs) and qualitative (live/dead and histology) assays. The results showed that the high porosity and interconnectivity of the SF-based scaffolds allowed cell adhesion over the scaffolds surface and a deeply cell penetration into the scaffolds interior. Cell viability and proliferation were also observed for 28 days of culturing in basal conditions and significant increase of GAGs content was detected on constructs cultured in chondrogenic differentiation medium. The obtained results demonstrated that the innovative approach of combining enzymatically cross-linked SF hydrogels with the salt-leaching and freeze-drying methodologies allowed to produce more versatile scaffold architectures with positive influence over in vitro biological performance, making this a valuable system not only for cartilage regeneration but also in other musculoskeletal TE strategies.

}, keywords = {Cartilage tissue engineering., Enzymatic cross-linking, Human adipose-derived stem cells, Macro-/micro-porous scaffolds, Silk Fibroin}, author = {Ribeiro, V. P. and da Silva Morais, A. and Oliveira, A. L. and Oliveira, J. M. and Reis, R. L.} }