Prolonged release of TGF-β from polyelectrolyte nanoparticle loaded macroporous chitin-poly(caprolactone) scaffold for chondrogenesis

Cartilage degeneration occurs when the catabolic factors overtakes the anabolic factors. The regeneration capability of damaged cartilage is poor due to its hypovascular and hypocellular tissue. Tissue engineering strategies aims in development of a suitable substrate that provide the required physical, chemical and biological cues to the proliferating cells to direct chondrogenesis. A macroporous polymeric blend scaffold of chitin and poly(caprolactone) (PCL) was fabricated by lyophilisation technique and characterized using Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric/Differential thermal Analysis (TG/DTA). The effect of prolonged release of Transforming growth factor-β (TGF-β) was studied by encapsulating it in chondroitin sulphate nanoparticles (nCS) incorporated in chitin-PCL scaffold. Chondroitin sulphate nanoparticles containing TGF-β (TGF-β-nCS) was developed by polyelectrolyte crosslinking using chitosan. Characterization of TGF-β-nCS by Dynamic Light Scattering particle sizer and SEM showed a 230 ± 20 nm sized spherical particles. Swelling and degradation studies of the composite scaffold showed its stability. Protein adsorption was enhanced in nanoparticle containing scaffold. The effect of TGF-β was well addressed by the increased attachment and proliferation of rabbit adipose derived mesenchymal stem cells (rASCs). The chondrogenic potential of rASCs in the presence of TGF-β releasing composite scaffold showed an increased proteoglycan deposition. These studies highlight the positive effects of chitin-PCL-TGF-β-nCS scaffold for cartilage regeneration.