Chitosan-genipin nanohydrogel as a vehicle for sustained delivery of alpha-1 antitrypsin

Alpha-1antitrypsin (A1AT) deficiency, an inherited disorder, has been shown to be the cause of lung diseases such as emphysema and chronic obstructive pulmonary disease. One of the treatment strategies to provide appropriate and adequate concentrations of A1AT in the lungsis the application of nanoparticles (NPs) in pulmonary drug delivery. In the current study, biocompatible nanohydrogels were prepared using chemically cross-linked chitosan with ginepin, a natural cross linker reagent, and used as a carrier to deposit A1AT into the lung tissue. Colloidal and monodispersed NPs were synthesized through reverse microemulsion. Nanohydrogels were characterized with TEM, LLS, FTIR, ZTEA potential, UV spectrum, and swelling test. Encapsulation efficacy was determined at different concentrations of A1AT using Bradford assay. Effect of processing variables such as pH, loading efficiency, and release media components on drug release profile was determined in simulated lung fluids. To evaluate the inhibitory activity of the A1AT after release from NPs, trypsin inhibitory capacity assay was carried out. Results from FTIR and UV spectrum confirmed the development of chitosan cross linkage. Spherical chitosan-genipin NPs were sized from 30-100 nm. NPs exhibited the ability to release 49% of the drug within 12-dayperiodatpH 7. However, there were variations with the drug release profile due to pH variations and loading efficacy. Drug release was higher in pseudo alveolar fluid in comparison with saline solution. These data indicate that application of chitosan nanohydrogels can be a useful tool for sustained release of A1AT in the lung tissue.