Enhancing osseointegration and mitigating bacterial biofilms on medical-grade titanium with chitosan-conjugated liquid-infused coatings

Abstract

Titanium alloys, in particular, medical-grade Ti-6Al-4 V, are heavily used in orthopaedic applications due to their high moduli, strength, and biocompatibility. Implant infection can result in biofilm formation and failure of prosthesis. The formation of a biofilm on implants protects bacteria from antibiotics and the immune response, resulting in the propagation of the infection and ultimately resulting in device failure. Recently, slippery liquid-infused surfaces (LIS) have been investigated for their stable liquid interface, which provides excellent repellent properties to suppress biofilm formation. One of the current limitations of LIS coatings lies in the indistinctive repellency of bone cells in orthopaedic applications, resulting in poor tissue integration and bone ingrowth with the implant. Here, we report a chitosan impregnated LIS coating that facilitates cell adhesion while preventing biofilm formation. The fabricated coating displayed high contact angles (108.2 ± 5.2°) and low sliding angles (3.56 ± 4.3°). Elemental analysis obtained using X-ray photoelectron spectroscopy (XPS) confirmed the availability of fluorine and nitrogen, indicating the presence of fluorosilane and chitosan in the final coating. Furthermore, our results suggest that chitosan-conjugated LIS increased cell adhesion of osteoblast-like SaOS-2 cells and significantly promoted proliferation (a fourfold increase at 7-day incubation) compared to conventional titanium liquid-infused surfaces. Furthermore, the chitosan conjugated LIS significantly reduced biofilm formation of methicillin-resistant Staphylococcus aureus (MRSA) by up to 50% and 75% when compared to untreated titanium and chitosan-coated titanium, respectively. The engineered coating can be easily modified with other biopolymers or capture molecules to be applied to other biomaterials where tissue integration and biofilm prevention are needed.

Biofunctionalization of Porous Titanium Oxide through Amino Acid Coupling for Biomaterial Design

“…In this respect, surface coatings with hydrophilic, highly hydrated uncharged polymers, e.g., polyethylene-glycol [ 13 , 14 ] or zwitterionic films [ 15 , 16 ] have been widely investigated to confer low adhesion, antifouling properties to the surface. In addition to low-adhesion surfaces, intrinsically bioactive antimicrobial coatings, including coatings involving quaternary ammonium salts [ 17 ], polymeric materials, such as chitosan [ 18 ] and its potentiated derivatives, and several metals [ 19 ], such as silver, zinc and copper have been widely investigated.…”

A Bifunctional Spray Coating Reduces Contamination on Surfaces by Repelling and Killing Pathogens

“…Engineered surfaces consisting of pathogen-repellent materials are being developed to reduce the initial attachment of pathogens and impede the transmission of infection through steric repulsion, hydrophobic interactions, electrostatic repulsion, and low surface energy. , The antiadhesion behavior of surfaces is governed by its chemical properties such as surface charge, wettability, its topology such as roughness, geometry, impregnation with lubricants, and other physical configurations. − Through the innovative design of nanoscale roughness, micrometer lateral dimensions, and well-defined structures of different sizes and shapes, engineered surfaces can prevent the initial adhesion of pathogens. Furthermore, the optimization of surface topography, such as radii, height, or density of protruding structures, can induce a significant stretching strain on the cell membrane of pathogens, causing lysis and death .…”

Highly Stable Hierarchically Structured All-Polymeric Lubricant-Infused Films Prevent Thrombosis and Repel Multidrug-Resistant Pathogens

“…Specifically, rapid adsorption of plasma proteins onto the surface of blood-contacting medical devices initiates a cascade of reactions that ends in clot formation and subsequent thrombosis. , In relation to infection, the adherence of bacteria onto the surface of such devices, while initially reversible, often develops into well-established, biofilm-based infections, which are difficult to treat . As a result, surface modification strategies aimed at preventing the initial adsorption of blood proteins and microorganisms have garnered significant interest as a means to prohibit device-associated thrombosis and infection. ,, …”

“…3 As a result, surface modification strategies aimed at preventing the initial adsorption of blood proteins and microorganisms have garnered significant interest as a means to prohibit deviceassociated thrombosis and infection. 2,4,5 A wide range of surface treatment approaches have been developed to improve the blood compatibility and antifouling properties of medical devices. In particular, liquid-infused surfaces (LIS) have been established as an effective strategy to prevent fouling on a wide range of devices, such as grafts, catheters, and implants.…”