Human placenta/umbilical cord derivatives in regenerative medicine - Prospects and challenges.

The human placenta and umbilical cord, natural birth biowaste, are a housing unit for numerous bioactive macromolecules, growth factors, collagen and GAGs, with an array of high-quality stem cells. MSCs isolated from the human placenta and umbilical cord are utilized in both research and medical applications due to their sustainable sourcing, high viability, multipotent lineage and potency. They present an unprecedented opportunity in the tissue engineering, biomedical and biotechnology fields with minimal ethical constraints and nominal cost. Considering the world population and daily birth rates, with appropriate utilization and management, they could resolve the MSC shortage in the global stem cell therapy market and present biomedical waste disposal. A considerable number of clinical trials are presently underway where placenta-derived stem cells have been administered for different pathologies. Since the umbilical cord and placenta's primary function is to sustain the fetus until delivery, it has an ample supply of nutrients, proteins and essential factors necessary to assist cell viability and proliferation. Present research and medical applications include the fabrication of ECM-based nanofibers, disease models, micro-tissue, hybrid models and artificial implants. Future utilization of birthing biomedical waste in medical engineering and research will provide a rich and sustainable source of stem cells and extracellular matrix for enhanced biocompatibility and regeneration.

Design modification of surgical drill bit for final osteotomy site preparation towards improved bone-implant contact.

Implant stability significantly impacts accelerated osseointegration, leading to faster patient recovery. Both primary and secondary stability necessitates superior bone-implant contact influenced by the surgical tool required to prepare the final osteotomy site. Besides, excessive shearing and frictional forces generate heat causing local tissue necrosis. Hence, surgical procedure necessitates proper irrigation with water to minimize heat generation. Notably, the water irrigation system removes bone chips and osseous coagulums, which may help accelerate osseointegration and improve bone-implant contact. The inferior bone-implant contact and thermal necrosis at the osteotomy site are primarily responsible for poor osseointegration and eventual failure. Therefore, optimizing tool geometry is key to minimizing shear force, heat generation, and necrosis during final osteotomy site preparation. The present study explores modified drilling tool geometry, especially cutting edge for osteotomy site preparation. The mathematical modeling is used to find out ideal cutting-edge geometry that facilitates drilling under relatively less operational force (0.55-5.24 N) and torque (98.8-154.5 N-mm) with a significant reduction (28.78%-30.87%) in heat generation. Twenty-three conceivable designs were obtained using the mathematical model; however, only three have shown promising results in static structural FEM platforms. These drill bits are designed for the final drilling operation and need to be carried out during the final osteotomy site preparation.