title: Potential of Agarose/Silk Fibroin Blended Hydrogel for in Vitro Cartilage Tissue Engineering.
abstract: An osteoarthritis pandemic has accelerated exploration of various biomaterials for cartilage reconstruction with a special emphasis on silk fibroin from mulberry (Bombyx mori) and non-mulberry (Antheraea assamensis) silk worms. Retention of positive attributes of the agarose standard and nullification of its negatives are central to the current agarose/silk fibroin hydrogel design. In this study, hydrogels of mulberry and non-mulberry silk fibroin blended with agarose were fabricated and evaluated in vitro for two weeks for cartilaginous tissue formation. The fabricated hydrogels were physicochemically characterized and analyzed for cell viability, proliferation, and extra cellular matrix deposition. The amalgamation of silk fibroin with agarose impacted the pore size, as illustrated by field emission scanning electron microscopy studies, swelling behavior, and in vitro degradation of the hydrogels. Fourier transform infrared spectroscopy results indicated the blend formation and confirmed the presence of both components in the fabricated hydrogels. Rheological studies demonstrated enhanced elasticity of blended hydrogels with G' > G″. Biochemical analysis revealed significantly higher levels of sulfated glycosaminoglycans (sGAGs) and collagen (p ≤ 0.01) in blended hydrogels. More specifically, the non-mulberry silk fibroin blend showed sGAG and collagen content (∼1.5-fold) higher than that of the mulberry blend (p ≤ 0.05). Histological and immunohistochemical analyses further validated the enhanced deposition of sGAG and collagen, indicating maintenance of chondrogenic phenotype within constructs after two weeks of culture. Real-time PCR analysis further confirmed up-regulation of cartilage-specific aggrecan, sox-9 (∼1.5-fold) and collagen type II (∼2-fold) marker genes (p ≤ 0.01) in blended hydrogels. The hydrogels demonstrated immunocompatibility, which was evidenced by minimal in vitro secretion of tumor necrosis factor-α (TNF-α) by murine macrophages. Taken together, the results suggest promising attributes of blended hydrogels and particularly the non-mulberry silk fibroin/agarose blends as alternative biomaterial for cartilage tissue engineering.
authors.affiliation: Biomaterial and Tissue Engineering Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati , Guwahati 781039, Assam, India.
authors.forename: Yogendra Pratap
authors.initials: YP
authors.lastname: Singh
authors.affiliation: Biological and Chemical Sciences Section, Life Sciences Division, Institute of Advanced Study in Science and Technology (IASST) , Guwahati 781035, Assam, India.
authors.forename: Nandana
authors.initials: N
authors.lastname: Bhardwaj
authors.affiliation: Biomaterial and Tissue Engineering Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati , Guwahati 781039, Assam, India.
authors.forename: Biman B
authors.initials: BB
authors.lastname: Mandal
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D012831:Bombyx; D002356:Cartilage; D005349:Fibroins; D020100:Hydrogels / Q000737:chemistry*; D051379:Mice; D012685:Sepharose; D023822:Tissue Engineering; D054457:Tissue Scaffolds
chemical_list: D001672:Biocompatible Materials; D020100:Hydrogels; D005349:Fibroins; D012685:Sepharose
keywords: agarose; cartilage; non-mulberry silk; silk fibroin; tissue engineering