In vitro augmentation of chondrogenesis by Epigallocatechin gallate in primary Human chondrocytes - Sustained release model for cartilage regeneration

Epigallocatechin-3-gallate (EGCG), a plant polyphenol catechin is potent chondrogenic drug which enhances cartilage regeneration. Hence, sustained release of EGCG from interlinked porous polycaprolactone (PCL) scaffolds can be beneficial in engineering a cartilage construct. In this study, 10% (w/v) and 12% (w/v) PCL scaffold were fabricated by incorporation of 2 different concentrations (1 mg/ml & 2 mg/ml) of EGCG loaded albumin nanoparticles (ENP). Morphological analysis of the fabricated scaffolds with Field emission scanning electron microscope (FESEM) revealed interlinked porous structures (pore size range 50 mu m-300 mu m) with embedded ENP on the scaffolds surface. In addition, the ENP synthesized by desolvation technique were spherical in shape with diameters in the range of 110 nm-210 nm. Further, X-ray diffraction of ENP and scaffolds implied amorphization of EGCG which is highly preferred in drug delivery application. Moreover, spectroscopic analysis with Fourier Transform Infrared (FTIR) and Raman spectrophotometry confirmed incorporation of ENP into scaffolds and chemical stability of PCL and EGCG during fabrication. Importantly, all groups showed sustained release for 22 days and non fickian diffusion through scaffolds. The drug release data also inferred that the concentration of ENP modulated EGCG release from scaffolds. Furthermore, in vitro chondrogenic study with Human chondrocytes for 21 days revealed significant increase in glycosaminoglycan deposition under the influence of EGCG. All these results suggest that ENP loaded polycaprolactone scaffolds, with intrinsic ability for releasing EGCG in a sustained fashion can serve as a prospective matrix in cartilage engineering.