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.

Cartilage tissue is deprived of intrinsic self-regeneration capability; hence, its damage often progresses to a chronic condition which reduces the quality of life. Toward the fabrication of functional tissue substitutes, three-dimensional (3D) bioprinting has progressed vastly over the last few decades. However, this progress is challenged by the difficulty in developing suitable bioink materials as most of them require toxic chemical cross-linking. In this study, our goal was to develop a cross-linker-free bioink with optimal rheology for polymer extrusion, aqueous, and nontoxic processing and offers structural support for cartilage regeneration. Toward this, we use the self-gelling ability of silk fibroin blends (Bombyx mori and Philosamia ricini) along with gelatin as a bulking agent. Silk and gelatin interact with each other through entanglement and physical cross-linking. The ink was rheologically and structurally optimized for printing efficiency in printing grid-like structures. The printed 3D constructs show optimal swelling capability, degradability, and compressive strength. Further, the construct supports the growth and proliferation of encapsulated chondrocytes and formation of the cartilaginous extracellular matrix as indicated by the increased sulfated glycosaminoglycan and collagen contents. This was further corroborated by the upregulation of chondrogenic gene expression with minimal hypertrophy of chondrocytes. Additionally, the construct demonstrates in vitro and in vivo biocompatibility. Notably, the ink demonstrates good print fidelity for printing anatomical structures such as the human ear enabled by optimized extrudability at adequate resolution. Altogether, the results indicate that the developed cross-linker-free silk–gelatin polymer-based bioink demonstrated high potential for its 3D bioprintability and application in cartilage tissue engineering.

A three-dimensional porous scaffolds based on muga silkworm, Antheraea assamensis was fabricated and well characterized for cartilage tissue engineering, which may present as noteworthy targets for the further development in chondrocytes based cartilage repair.

Starch modified polyol based tough, biodegradable, biocompatible hyperbranched polyurethane with excellent thermoresponsive shape memory behavior near body temperature was demonstrated.

Development of a bio-based smart implantable material with multifaceted attributes of high performance, potent biocompatibility and inherent antibacterial property, particularly against drug resistant bacteria, is a challenging task in biomedical domain. Addressing these aspects at the bio-nano interface, we report the in situ fabrication of starch modified hyperbranched polyurethane (HPU) nanocomposites by incorporating different weight percentages of carbon dot-silver nanohybrid during polymerization process. This nanohybrid and its individual nanomaterials (Ag and CD) were prepared by facile hydrothermal approaches and characterized by various instrumental techniques. The structural insight of the nanohybrid, as well as its nanocomposites was evaluated by TEM, XRD, FTIR, EDX and thermal studies. The significant improvement in the performance in terms of tensile strength (1.7 fold), toughness (1.5 fold) and thermal stability (20 °C) of the pristine HPU was observed by the formation of nanocomposite with 5 wt.% of nanohybrid. They also showed notable shape recovery (99.6%) and nearly complete self-expansion (>99%) just within 20s at (37 ± 1) °C. Biological assessment established in vitro cytocompatibility of the HPU nanocomposites. The fabricated nanocomposites not only assisted the growth and proliferation of smooth muscle cells and endothelial cells that exhibited reduced platelet adhesion but also displayed in vitro hemocompatibility of mammalian RBCs. Significantly, the antibacterial potency of the nanocomposites against Escherichia coli MTCC 40 and Staphylococcus aureus MTCC 3160 bacterial strains vouched for their application to countercheck bacterial growth, often responsible for biofilm formation. Thus, the present work forwards the nanocomposites as potential tough infection-resistant rapid self-expandable stents for possible endoscopic surgeries.

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Osteochondral tissue engineering has become a promising strategy for repairing focal chondral lesions and early osteoarthritis (OA), which account for progressive joint pain and disability in millions of people worldwide. This review helps in providing a more comprehensive and systematic overview of utilizing injectable hydrogels for osteochondral repair.

Radio propagation is essential for emerging technologies with appropriate design, deployment and management strategies for any wireless network. It is heavily site specific and can vary significantly depending on terrain, frequency of operation, velocity of mobile terminal, interface sources and other dynamic factor. Accurate characterization of radio channel through key parameters and a mathematical model is important for predicting signal coverage, achievable data rates, BER and Antenna gain.Large scale path loss modeling plays a fundamental role in designing both fixed and mobile radio systems. Predicting the radio coverage area of a system is not done in a standard manner. Wireless systems are expensive systems. Therefore, before setting up a system one has to choose a proper method depending on the channel's BTS antenna height gain. By proper selecting the above parameters there is a need to select the particular communication model which show good result by considering these parameters.