Nanosilver/poly (DL-lactic-co-glycolic acid) on titanium implant surfaces for the enhancement of antibacterial properties and osteoinductivity

Abstract

Xuemin Zeng,1,2 Shijiang Xiong,1,3 Shaoyang Zhuo,1,4 Chunpeng Liu,1,2 Jie Miao,5 Dongxu Liu,1,2 Hengxiao Wang,6 Yueying Zhang,6 Zhong Zheng,7,8 Kang Ting,8 Chunling Wang,1,2 Yi Liu1,2 1Shandong Provincial Key Laboratory of Oral Tissue Regeneration, School of Stomatology, Shandong University, Jinan, People’s Republic of China; 2Department of Orthodontics, School of Stomatology, Shandong University, Jinan, People’s Republic of China; 3Department of Endodontics, School of Stomatology, Shandong University, Jinan, People’s Republic of China; 4Department of Oral Maxillofacial Surgery, School of Stomatology, Shandong University, Jinan, People’s Republic of China; 5Department of Stomatology, The 5th People’s Hospital of Jinan, Jinan, People’s Republic of China; 6Department of Experimental Pathology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Jinan, People’s Republic of China; 7Section of Orthodontics, Division of Growth and Development, School of Dentistry, University of California, Los Angeles, CA, USA; 8UCLA Division of Plastic and Reconstructive Surgery, Department of Orthopaedic Surgery, Orthopaedic Hospital Research Center, University of California, Los Angeles, CA, USA Background: Despite titanium (Ti) implants have been commonly used in the medical device field due to their superior biocompatibility, implant-associated bacterial infection remains a major clinical complication. Nanosilver, an effective antibacterial agent against a wide spectrum of bacterial strains, with a low-resistance potential, has attracted much interest too. Incorporation of nanosilver on Ti implants may be a promising approach to prevent biofilm formation. Purpose: The objective of the study was to investigate the antibacterial effects and osteoinductive properties of nanosilver/poly (dl-lactic-co-glycolic acid)-coated titanium (NSPTi). Methods: Gram-positive methicillin-resistant Staphylococcus aureus (MRSA) and the Gram-negative opportunistic pathogen Pseudomonas aeruginosa (PAO-1) were used to evaluate the antibacterial activity of NSPTi implants through the analysis of bacterial colonization in vitro and in vivo. Furthermore, we examined the osteoinductive potential of NSPTi implants by investigating the proliferation and differentiation of MC3T3-E1 preosteoblast cells. In vivo, the osteoinductive properties of NSPTi implants were assessed by radiographic evaluation, H&E staining, and Masson’s trichrome staining. Results: In vitro, bacterial adhesion to the 2% NSPTi was significantly inhibited and <1% of adhered bacteria survived after 24 hours. In vitro, the average colony-forming units (CFU)/g ratios in the 2% NSPTi with 103 CFU MRSA and PAO-1 were 1.50±0.68 and 1.75±0.6, respectively. In the uncoated Ti groups, the ratios were 1.03±0.82×103 and 0.94±0.49×103, respectively. These results demonstrated that NSPTi implants had prominent antibacterial properties. Proliferation of MC3T3-E1 cells on the 2% NSPTi sample was 1.51, 1.78, and 2.22 times that on the uncoated Ti control after 3, 5, and 7 days’ incubation, respectively. Furthermore, NSPTi implants promoted the maturation and differentiation of MC3T3-E1 cells. In vivo, NSPTi accelerated the formation of new bone while suppressing bacterial survival. Conclusion: NSPTi implants have simultaneous antibacterial and osteoinductive activities and therefore have the potential in clinical applications. Keywords: silver nanoparticles, Ti, antimicrobial, osteogenesis, infection

Keywords

• silver nanoparticles
• titanium
• antimicrobial
• osteogenesis
• infection