Fibrin–Polyurethane Composites for Articular Cartilage Tissue Engineering: A Preliminary Analysis

Abstract

In this study we investigated the use of a fibrin hydrogel to improve the potential of a polyurethane (PU) scaffold-based system for articular cartilage tissue engineering. PU-only ("no-fibrin") and PU-fibrin ("fibrin") composites were cultured for up to 28 days and analyzed for DNA content, glycosaminoglycan (GAG) content, type II collagen content, GAG release, and gene expression of aggrecan, collagen I, and collagen II. The use of fibrin allowed for higher viable cell-seeding efficiency (10% higher DNA content on day 2 in fibrin versus no-fibrin composites) and more even cell distribution on seeding, a more than 3-fold increase in the percentage of newly synthesized GAG retained in the constructs, and 2- to 6-fold higher levels of type II collagen and aggrecan gene expression through day 14. Addition of aprotinin to the medium inhibited fibrin degradation, most noticeably in the center of the constructs, but had little effect on biochemical composition or gene expression. Short-term mechanical compression (0-10% sinusoidal strain at 0.1 Hz for 1 h, applied twice daily for 3 days) doubled the rate of GAG release from the constructs, but had little effect on gene expression, regardless of the presence of fibrin. Although further work is needed to optimize this system, the addition of fibrin hydrogel to encapsulate cells in the stiff, macroporous PU scaffold is a step forward in our approach to articular cartilage tissue engineering.

Stem Cell–Soluble Signals Enhance Multilumen Formation in SMG Cell Clusters

“…Scaffold compliance is another critical variable in promoting cell differentiation and morphogenesis, since it could inhibit growth if not optimized (Peters et al 2014). Ultimately, the cross-linking of pure L1 peptides with FH could be combined with nonbioactive materials, such as polyurethane and polyethylene glycol, to further improve compliance and support salivary cell growth, organization, and differentiation (Lee et al 2005;Peled et al 2007;Ahmed et al 2008).…”

Bioengineering of Articular Cartilage: Past, Present and Future

“…[92]; [206]; [207]; [208]; [209]; [210]; [211]; [212]; [209]; [213] Poly(ethylene glycol) Hydrophilicity [218]; [219] …”

Strategies for Improving the Repair of Focal Cartilage Defects

“…Crosslinking methods include light irradiation, temperature modulation and pH alteration [33]. Hydrogels used for chondrogenesis can be naturally-derived such as agarose [44,45], collagen [46,47], fibrin [48,49], alginate [50][51][52] and hyaluronan [53]; or derive from synthetic polymers such as polyethylene glycols hydrogels [54,55]. Some studies have shown that less crosslinked (softer) hydrogels produce dynamic loading that might favor MSC chondrogenesis [56,57].…”