**Antibacterial and Bioactive Surface Modifications of Titanium Implants by PCL/TiO2 Nanocomposite Coatings**

**A. Sandeep Kranthi Kiran 1,2,3, T.S. Sampath Kumar 1,\*, Rutvi Sanghavi 2, Mukesh Doble <sup>2</sup> and Seeram Ramakrishna 3,\***


Received: 5 October 2018; Accepted: 18 October 2018; Published: 20 October 2018

**Abstract:** Surface modification of biomedical implants is an established strategy to improve tissue regeneration, osseointegration and also to minimize the bacterial accumulation. In the present study, electrospun poly(ε-caprolactone)/titania (PCL/TiO2) nanocomposite coatings were developed on commercially pure titanium (cpTi) substrates for an improved biological and antibacterial properties for bone tissue engineering. TiO2 nanoparticles in various amounts (2, 5, and 7 wt %) were incorporated into a biodegradable PCL matrix to form a homogeneous solution. Further, PCL/TiO2 coatings on cpTi were obtained by electrospinning of PCL/TiO2 solution onto the substrate. The resulted coatings were structurally characterized and inspected by employing scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. Given the potential biological applications of PCL/TiO2 coated cpTi substrates, the apatite-forming capacity was examined by immersing in simulated body fluid (SBF) for upto 21 days. Biocompatibility has been evaluated through adhesion/proliferation of hFOB osteoblast cell lines and cytotoxicity by MTT assay. Antimicrobial activity of PCL/TiO2 nanocomposites has been tested using UV light against gram-positive Staphylococcus aureus (*S.aureus*). The resulting surface displays good bioactive properties against osteoblast cell lines with increased viability of 40% at day 3 and superior antibacterial property against *S.aureus* with a significant reduction of bacteria to almost 76%. Surface modification by PCL/TiO2 nanocomposites makes a viable approach for improving dual properties, i.e., biological and antibacterial properties on titanium implants which might be used to prevent implant-associated infections and promoting cell attachment of orthopedic devices at the same time.

**Keywords:** titanium; antibacterial coatings; electrospinning; nanocomposite coatings; TiO2 photocatalytic; orthopedic infections
