title: Surface functionalization of titanium substrates with chitosan-lauric acid conjugate to enhance osteoblasts functions and inhibit bacteria adhesion.
abstract: Orthopedic implants failures are generally related to poor osseointegration and/or bacterial infection in clinical application. Surface functionalization of an implant is one promising alternative for enhancing osseointegration and/or reducing bacterial infection, thus ensuring the long term survival of the implant. In this study, titanium (Ti) substrates were surface functionalized with a polydopamine (PDOP) film as an intermediate layer for post-immobilization of chitosan-lauric acid (Chi-LA) conjugate. Chi-LA conjugate was synthesized and characterized by Fourier transform infrared spectroscopy (FTIR) and hydrogen proton nuclear magnetic resonance (NMR) spectrometer, respectively. Lauric acid (LA), a natural saturated fatty acid, was used mainly due to its good antibacterial property. Scanning electron microscopy (SEM) and water contact angle measurements were employed to detect the morphology changes and surface wettability of Ti substrates. The results suggested that Chi-LA conjugate was successfully immobilized onto the surfaces of Ti substrates. In vitro tests confirmed that the cell adhesion, cell viability, intracellular alkaline phosphatase activity and mineralization capacity of osteoblasts were remarkably improved when cultured onto Chi-LA surface functionalized Ti substrates. Antibacterial assay against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) showed that the Chi-LA modified Ti substrates efficiently inhibited the adhesion and growth of bacteria. Overall, this study developed a promising approach to fabricate functional Ti-based orthopedic implants, which could enhance the biological functions of osteoblasts and concurrently reduce bacteria adhesion.
authors.affiliation: Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, PR China.
authors.forename: Lu
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, PR China. Electronic address: huyan303@cqu.edu.cn.
authors.forename: Yan
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, PR China.
authors.forename: Dawei
authors.initials: D
authors.lastname: Xu
authors.affiliation: Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, PR China. Electronic address: kaiyong_cai@cqu.edu.cn.
authors.forename: Kaiyong
authors.initials: K
authors.lastname: Cai
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D001422:Bacterial Adhesion / Q000187:drug effects; D002448:Cell Adhesion / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D048271:Chitosan / Q000737:chemistry*; D006001:Glycoconjugates / Q000138:chemical synthesis* / Q000494:pharmacology; D007211:Indoles / Q000737:chemistry; D007850:Lauric Acids / Q000737:chemistry* / Q000494:pharmacology; D010006:Osteoblasts / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology; D011108:Polymers / Q000737:chemistry; D061251:Primary Cell Culture; D019736:Prostheses and Implants; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000254:growth & development; D051381:Rats; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D006001:Glycoconjugates; D007211:Indoles; D007850:Lauric Acids; D011108:Polymers; C568283:polydopamine; C030358:lauric acid; D048271:Chitosan; D014025:Titanium; D000469:Alkaline Phosphatase
keywords: Antibacterial property; Lauric acid; Osteoblasts; Proliferation; Titanium