Indian Institute of Technology Guwahati

About: Indian Institute of Technology Guwahati is a education organization based out in Guwahati, Assam, India. It is known for research contribution in the topics: Catalysis & Computer science. The organization has 6933 authors who have published 17102 publications receiving 257351 citations.

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.

CD271+ Bone Marrow Mesenchymal Stem Cells May Provide a Niche for Dormant Mycobacterium tuberculosis

Abstract: Mycobacterium tuberculosis (Mtb) can persist in hostile intracellular microenvironments evading immune cells and drug treatment. However, the protective cellular niches where Mtb persists remain unclear. We report that Mtb may maintain long-term intracellular viability in a human bone marrow (BM)–derived CD271+/CD45− mesenchymal stem cell (BM-MSC) population in vitro. We also report that Mtb resides in an equivalent population of BM-MSCs in a mouse model of dormant tuberculosis infection. Viable Mtb was detected in CD271+/CD45− BM-MSCs isolated from individuals who had successfully completed months of anti-Mtb drug treatment. These results suggest that CD271+ BM-MSCs may provide a long-term protective intracellular niche in the host in which dormant Mtb can reside.