Preparation, Characterization and Applications of Nanoparticles from Chitosan

Abstract

Chitosan is a naturally occurring amino polysaccharide and largely applicable in biomedical field as it is biodegradable, biocompatible and nontoxic. The nanoparticles of chitosan have gained more focus in the delivery of drugs and also in sustaining drug release for increasing drug bioavailability. The main source of chitosan are the discarded exoskeleton of crustaceans. Thus, the aim of the present research was to extract chitosan from wasted shrimp shell and to formulate and evaluate chitosan based nanoparticles of different types of drugs in enhancement of residence time and bioavailability of drugs in the human body. First, chitosan was extracted from shrimp shell by demineralization, deproteination and deacetylation. Then it was characterized by various methods, mainly solubility, molecular weight (MW), degree of deacetylation (DDA) determination and elemental analysis, FTIR analysis and XRD pattern analysis. The outcomes of the study represnts that, the solubility of extracted chitosan was about 83%, while the MW was 2.3 x 10 Da and DDA was 70%. Based on these results, the extracted chitosan was considered to have the qualities to be used in biomedical field. Thus the extracted chitosan was used to formulate a novel drug delivery system for different types of drugs. In this regard, three antibiotic drugs and one antihypertensive drug was loaded to this drug delivery system individually with improved association efficiency to enhance the drug bioavailability within the body and also for the enhancement of the antibacterial activity for the antibiotic drugs. The drug delivery systems of chitosan nanoparticles (CSNPs) was prepared by ionic gelation method and the drugs were loaded to this delivery system during the nanoparticle formation. The conditions applied and the results obtained were different from previous studies. After drug loading on CSNPs, the physicochemical properties were investigated by SEM and TEM analysis for morphology study and particle size observation, FTIR and XRD analysis. The association efficiencies of the different drug loaded CSNPs were found to be in the range of 88-93%. The TEM analysis confirms the formation of nano sized particles as well as the adsorption of drug molecules on the surface of the nanoparticles. All of the drug loaded nanoparticles prepared in this study shows sustained release of drugs after initial rapid release in the case of in vitro release studies. Thus, the adsorption of drugs on the surface of nanoparticles results the sustained release of drugs from nanoparticles without encapsulation. This sustained release properties of these drug delivery systems improve the dug bioavailability in the body. Besides, the antibacterial activities of antibiotic drug loaded CSNPs against both gram (+) and gram (-) bacteria shows that they could inhibit the bacterial growth. The value of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) showed that the inhibitory effect of prepared antibiotic loaded nanoparticles on specific bacterial strain was similar to that of the corresponding antibiotic in the in vitro cases. Thus the drug delivery system from CSNPs prepared in this study can be a promising drug delivery system.