ABSTRACT
Zinc oxide nanoparticles (ZnO NPs) are one of the most abundant metal oxides nanoparticles. It provides excellent thermal, electrical and chemical stabilities with low biotoxicity; its photo-oxidising and photo-catalytic impact on biological and chemical species is of great importance, thereby making it a promising candidate to be used for in-vitro and in-vivo studies in biomedical field. Hereby, ZnO NPs were synthesized using precipitation method with zinc acetate and sodium hydroxide as starting materials. This study has characterized the synthesized ZnO NPs using different techniques such as UV-Visible spectroscopy indicating a peak at 365 nm wave length, size of ZnO NPs was determined to be 286.7 nm by measuring hydrodynamic radii using Dynamic Light Scattering (DLS) phenomena. Further predominant charge existing at surface of the synthesised ZnO NPs was evaluated to be 31.6mV. Anti-microbial activity of ZnO NPs was determined by Kirby-Bauer method for both Gram-positive and Gram-negative bacteria, S. aureus and E. colirespectively. Anti-microbial activity was determined as Zone of Inhibition that measures both bactericidal and bacteriostatic activity of ZnO NPs and was found to be more potent for Gram-positive (S. aureus)bacteria and its activity increased with increasing concentration of nanoparticles. Growth kinetics was studied to determine percentage growth inhibition, for this optical density was recorded as a function of time in bacterial culture broth with and without treatment. Further DNA fragmentation assay was performed to determine genotoxicity caused by nanoparticles and its effect on genomic DNA of bacteria. Highlighting its potential role as a nano-carrier system for leading antibacterial drugs for enhanced effectiveness of the antibacterial therapies
ABSTRACT
Nanobiotechnology focuses on the biological effects and applications of nanoparticles that include nano-safety, drug encapsulation and nanotherapeutics. The present study focuses on hydrophilic nanospheres of copolymers N-isopropylacrylamide [NIPAAM] and vinyl pyrrolidone [VP], encapsulating a bioactive derivative of 5-fluorouracil-hexyl-carbamoyl fluorouracil (HCFU). The size of the nanospheres was ~58 nm and the surface charge measured was -15.4 mV. Under optimal conditions, the yield was >80%, and the drug loading was 2%. The entrapment efficiency was ~75%. Wide-angle X-ray diffraction analysis showed that the entrapped HCFU was present in an amorphous state, which has higher water solubility compared with the crystalline state. Slow drug release from nanospheres was observed in PBS and serum, with ~80% released at 37°C after 72 h. The HCFU loaded polymeric nanospheres have been found to be stable in whole blood having negligible RBC toxicity. Cytotoxicity in Mia-Paca 3, pancreatic cancer cell line was done in a 24-72 h assay. Dose dependant cytotoxicity was observed when incubated with various concentrations of HCFU loaded polymeric nanospheres while HCFU per se (<1 mg) showed 90% toxicity within 24 h.