ORIGINAL PAPER Improved antibacterial activity of HAP garlanded PLGA ultrafine fibers incorporated with CuO: synthesis and characterization Musarat Amina • M. Shamshi Hassan • Nawal Musayeib Al Musayeib • Touseef Amna • Myung-Seob Khil Received: 9 December 2013 / Accepted: 10 March 2014 / Published online: 21 March 2014 Ó Springer Science+Business Media New York 2014 Abstract Well-organized nanocrystalline hydroxyapatite nanoparticles garlanded poly(DL-lactide-co-glycolide) (PLGA) ultrafine fibers with efficient antibacterial proper- ties are of great interest in the development of new pro- ducts. 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 disper- sive X-ray analysis, and electron probe mapping analysis. The in vitro antimicrobial activity of synthesized pure and hydroxyapatite doped PLGA ultrafine fibers was investi- gated 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 lm 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. Keywords Nanohydroxyapatite Á Copper oxide Á Antimicrobial Á Ultrafine fibers 1 Introduction Nanotechnology manipulates matter at nanoscaler dimen- sions, creating innovative nanoproducts with novel char- acteristics [1]. One of the most challenging fields of materials science is fabrication of new hybrid biomaterials with novel properties. The scientific researches make continuous attempts to create new and improved biomate- rials with definite medicinal applications. In recent years, nanocomposites have received considerable attention due to their unique chemical and physical properties such as nanometrix sizes, high surface area, and high reactivity. Nanocomposites are a new class of materials based on organic polymers and inorganic substances. Combining both counterparts (organic/inorganic) in one material uses the advantages of flexibility and good mold ability of the organic part, and heat stability, high strength, and chemical M. Amina Á N. M. Al Musayeib Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia M. S. Hassan Á M.-S. Khil (&) Department of Organic Materials and Fiber Engineering, Chonbuk National University, Chonju 561-756, Republic of Korea e-mail: mskhil@jbnu.ac.kr T. Amna (&) Department of Animal Science and Biotechnology, Chonbuk National University, Chonju 561-756, Republic of Korea e-mail: touseefamna@gmail.com 123 J Sol-Gel Sci Technol (2014) 71:43–49 DOI 10.1007/s10971-014-3330-8