Polymer biocomposite nanoparticles for sustained drug delivery.

Nanoparticles of ~10 nm in diameter made with chitosan or lactic acid-graftedchitosan were developed for high drug loading and prolonged drug release. A drug encapsulation efficiency of 94.4% and a release rate of 28% from chitosan nanoparticles after 24 hours were demonstrated with bovine serum protein. A drug encapsulation efficiency of 97% and a release rate of 38% from chitosan nanoparticles after 24 hours were demonstrated with Diclofenac sodium. To further increase drug encapsulation, prolongdrug release, and increase chitosan solubility in solution of neutral pH, chitosan was modifiedwith lactic acid by grafting D,L-lactic acid onto amino groups in chitosan without using a catalyst.The lactic acid-grafted chitosan nanoparticles demonstrated a drug encapsulation efficiency of96% and a protein release rate of 15% after 24 hours. And in case of diclofenac,drug encapsulation efficiency of 98% and a diclofenac release rate of 25% after 24 hours. Unlike chitosan, whichis generally soluble only in acid solution, the chitosan modified with lactic acid can be preparedfrom solutions of neutral pH, offering an additional advantage of allowing proteins or drugs tobe uniformly incorporated in the matrix structure with minimal or no denaturization.

Synergistic activity of ofloxacin and ornidazole on biomedical fabrics against nosocomial pathogens.

Nosocomial infections in the hospitals disseminated from the cotton fabrics of health care professionals and patients leads to severe complications like respiratory, gastrointestinal and urinary tract infections. Since the hospital based textile materials like nylon and polyester has good surface properties, it can harbour large number of microorganisms. Hence in this study, two different antibacterial drugs showing synergistic properties were attached to different fabricsusing tocopherol acetate as a cross-linker with the aim that, treated fabric could act as barriers against transmission of challenge organisms. Inorder to decrease the drug resistant property of the nosocomial pathogens, a fluoroquinolone and a nitroimidazole compounds were mixed at suitable composition based on their synergistic behaviour. Both the compounds were modified to act as reactive dyes and were covalently bonded to the surface of nylon and polyester in order to impart antibacterial properties. The assay used for measuring antibacterial properties was based on the AATCC Test Method-100. The treated fabric was also subjected to multiple washings to determine its durability based on the AATCC Test Method-124. To determine the mode of action of these drugs, DNA of the drug exposed and unexposed challenge organisms were extracted and analysed by agarose gel electrophoresis. The difference in the number of viable bacteria after ‘0’ contact time and 18 hours contact time with treated fabrics were statistically calculated with P<0.05 considered significant.