Hydrogel formation by radiation induced crosslinked copolymerization of acrylamide onto moringa gum for use in drug delivery applications

Keeping in view the importance of polysaccharides gum in designing drug delivery systems, the present work is the exploration of the potential of the moringa gum in hydrogel formation via radiation induced crosslinking method for drug delivery applications. These polymers were characterized by cryo-SEM, AFM, FTIR, ¹³C-NMR spectroscopy and swelling studies. Some properties of the polymers such as blood compatibility, antioxidant activity, mucoadhesion and gel strength were also determined along with the evaluation of drug release profile of an antibiotic drug levofloxacin. The slow release of drug was observed without burst effect from the drug loaded hydrogels. Release of drug occurred through non-Fickian diffusion mechanism and release profile best fitted in Korsmeyer-Peppas kinetic model. Cryo-SEM showed the porous nature of the hydrogels. The polymers were found to be mucoadhesive and antioxidant in nature. These results indicated that these pure and sterile polymers can be proposed as gastrointestinal drug delivery system.

Gel microstructure regulates proliferation and differentiation of MC3T3-E1 cells encapsulated in alginate beads

For cell transplantation into damaged tissues, viable cells must be delivered to the defect site in a suitable carrier. However, the hypoxic and nutrient-limited environment in the carrier can induce massive cell death. The aims of this study were to increase the viability and regulate the behavior of osteoprogenitor cells encapsulated in alginate hydrogels through control of the gel microstructure. Cell survivability in alginate beads was improved through the use of α-MEM as the solvent for alginic acid sodium salt, and by CaCl(2) solutions, which supplied additional nutrients for the cells compared to water or buffer. The mesh size and shear modulus of the hydrogel were hypothesized to regulate proliferation and differentiation of osteoprogenitor cells. MC3T3-E1 cells demonstrated enhanced osteoblast differentiation when encapsulated in high-density alginate with smaller mesh size and more rigid mechanical properties, as confirmed by increased alkaline phosphatase activity and osteocalcin secretion. However, MC3T3-E1 cells encapsulated in low-density alginate beads with a larger mesh size and more compliant mechanical properties exhibited increased proliferation. These results demonstrate that the microstructure of alginate hydrogels can regulate the behavior of osteoprogenitor cells, thus suggesting that the tuning the properties of the gel may be a useful approach for enhancing new bone formation.