Nano-in-micro alginate based hybrid particles

Novel template containing ‘Nanoparticles (gelatin and CaCO3) embedded in Microspheres’ (‘Nano-in-micro’) was developed using atomization. Dexamethasone loaded gelatin nanoparticles, fluorescein isothiocyanate–dextran (FITC–dex) loaded CaCO3 nanoparticles and alginate based ‘Nano-in-micro’ system were prepared and characterized using optical microscopy, SEM, TEM, DLS, zeta potential, CLSM and FTIR. The results indicate that spherical, non-aggregating, ‘nano-in-micro’ particles (5–60 μm) can be prepared using atomization technique. Dexamethasone release from gelatin nanoparticles and ‘nano-in-micro’ systems indicated a decrease in burst release in the order: uncoated (24%) > coated (18%) > ‘nano-in-micro’ system (1:4 ratio) (17%). The sustained release decreased in order of ‘nano-in-micro’ (1:4 ratio) (14 days) > coated nanoparticles (9 days) > uncoated nanoparticles (4 days) for 95% drug release. FITC–dex loading and release from CaCO3 nanoparticles were found to be molecular weight dependent. Thus, ‘nano-in-micro’ systems show possibility for use as drug release vehicles, biosensors and multifunctional systems.