Fabrication and characterization of alginate-keratin based composite microspheres containing bioactive glass for tissue engineering applications

3D cell encapsulation within hydrogels has attracted more and more attention in tissue engineering applications because hydrogels provide a hydrated environment closely mimicking the in vivo environment for cell and tissue growth1. This present study considers the fabrication of alginate-keratin based composite microspheres containing bioactive glass (BG) of 45S5 composition for cell encapsulation. We propose the use of alginate di-aldehyde (ADA) synthesized via periodate oxidation of alginate to enhance the biodegradability of alginate, and the incorporation of keratin into the alginate based hydrogel to improve cellular interaction of the hydrogel. Keratins extracted from wool contain cell adhesive peptide sequences including RGD (arginine-glycine-aspartic acid), and LDV (leucine-aspartic acid-valine)2. BG particles, well known for promoting calcium phosphate deposition, were incorporated into the microspheres to enhance osseointegration3. The microspheres were prepared via a pressure-driven extrusion technique. Weight loss, protein release measurements, and FTIR spectroscopy of the fabricated microspheres were carried out. The morphology and microstructure of the microspheres were investigated by light microscopy and scanning electron microscopy (SEM), respectively. The results demonstrated that the composition of the hydrogels had a significant effect on their physical properties. Biological properties of ADA-keratin based microspheres were evaluated by encapsulating MG-63 osteosarcoma cells into the microspheres. Cell viability of MG-63 cells in ADA-keratin-1%BG hydrogels was found to be comparable to that of alginate-keratin and ADA-keratin after culturing for 21 days. The results proved that such novel composite hydrogel might be a promising material for biofabrication in bone healing approaches. Please click Additional Files below to see the full abstract

An innovative arteriovenous (AV) loop breast cancer model tailored for cancer research

Animal models are important tools to investigate the pathogenesis and develop treatment strategies for breast cancer in humans. In this study, we developed a new three-dimensional in vivo arteriovenous loop model of human breast cancer with the aid of biodegradable materials, including fibrin, alginate, and polycaprolactone. We examined the in vivo effects of various matrices on the growth of breast cancer cells by imaging and immunohistochemistry evaluation. Our findings clearly demonstrate that vascularized breast cancer microtissues could be engineered and recapitulate the in vivo situation and tumor-stromal interaction within an isolated environment in an in vivo organism. Alginate–fibrin hybrid matrices were considered as a highly powerful material for breast tumor engineering based on its stability and biocompatibility. We propose that the novel tumor model may not only serve as an invaluable platform for analyzing and understanding the molecular mechanisms and pattern of oncologic diseases, but also be tailored for individual therapy via transplantation of breast cancer patient-derived tumors