Improved antibacterial activity of HAP garlanded PLGA ultrafine fibers incorporated with CuO: synthesis and characterization

Abstract

Well-organized nanocrystalline hydroxyapatite nanoparticles garlanded poly(dl-lactide-co-glycolide) (PLGA) ultrafine fibers with efficient antibacterial properties are of great interest in the development of new products. In the present study, hydroxyapatite doped PLGA ultrafine fibers incorporated with copper oxide nanocrystals were fabricated via two step methodology. Primarily; copper oxide nanocrystals were synthesized using wet chemical method. Then the as-synthesized nanocrystals were used for the preparation of composite fibers using electrospinning technique. The properties of pure and composite ultrafine fibers were characterized using X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, and electron probe mapping analysis. The in vitro antimicrobial activity of synthesized pure and hydroxyapatite doped PLGA ultrafine fibers was investigated against model organism Escherichia coli (gram negative) using optical density method and morphological damage was observed by TEM. Ultrafine fibers with average diameter ranges from 1.0 to 1.2 μm were obtained. Uniform distribution of hydroxyapatite was observed. Admirable antimicrobial activity against E. coli was achieved which could be attributed by the synergy between hydroxyapatite and copper oxide. In contrast to pristine PLGA, lower concentrations of hydroxyapatite–copper oxide doped PLGA nanocomposite were needed to strongly inhibit the growth of E. coli. Our results report successful preparation of hydroxyapatite–copper oxide based novel nanocomposite. The developed hybrid nanocomposite possess exceptionally good antibacterial activity against E. coli due to the synergistic effect of hydroxyapatite and copper oxide. The antimicrobial nanocomposite can be utilized for a range of bio-functional purposes such as a good candidate for water purification, antibiofouling, wound dressings and bone tissue engineering etc.