Antibacterial PHAs coating for titanium implants

Abstract

Biomaterial-associated infection is a serious complication of modern implantation surgery.Thus, the improvement of implant surfaces is required to avoid the first stage for biofilm formation, bacterial adhesion. The current research addresses this issue by developing drug delivery systems (DDS) consisting of antibiotic-loaded polyhydroxyalkanoates (PHAs) coatings on titanium implants. Dip-coating technique was used to achieve optimal coatings with biodegradable biopolyesters, polyhydroxybutyrate (PHB) and its copolymer, polyhydroxybutyrate-co-hydroxyvalerate (PHBV). The coatings were completely characterized (wettability, topography, thickness and roughness), and studies of drug delivery, toxicity, antibacterial effect, and cell adhesion were performed. For both of biopolymers, surfaces were partially covered with 1 and 3 immersions, while with 6, they were completely covered. Although both antibiotic-loaded biopolymer coatings assure the protection against bacteria populations, PHBV coatings are closer to the desired release profile; its faster degradation provides for a greater and more stable drug release for a given period of time compared to PHB coatings. The use of coatings with different drug concentration per layer results in more controlled and homogeneous releases. The DDS designed not only assure toavoid the first stage of bacterial adhesion, but also their proliferation and biofilm formation, since the coatings degrade with time under physiological conditions, guaranteeing a prolonged drug release.

A New Antimicrobial Agent: Poly (3‐hydroxybutyric acid) Oligomer

“…Because of its bio‐degradability, the PHB long‐chain polymer also has been a focus of research interest in biomedical disciplines, including controlled drug delivery, surgical structure, wound dressing, vascular graft, blood vessel, orthopedic devices, tissue engineering, and skin substitutes . To date, studies on the antibacterial properties of PHB have involved PHB with the addition of other antibacterial agents or with chemically grafted antimicrobial moieties …”

Biomedical Applications of Polyhydroxyalkanoates

“…PHB and its copolymer P(3HB-3HHx) sheets loaded with lysozyme are being used for biofilm inhibition and in fabrication of wound dressing [89]. Implants coated with PHB copolymer fastens the degradation process for a stable drug release within a given time period as compared to its co-polymer [90,91].…”

Influence of ionic liquid on graphite/silver nanoparticles dispersion and antibacterial properties against Escherichia coli of PP/EPDM composite coatings

“…Several authors have reported the effect of clay nanoparticles in the processing and mechanical properties of nanocomposites based on EPDM/Polyolefin blends, using various types of compatibilizers . On the other hand, microbial contamination has increasingly threatened human health with the increasing appearance of antibiotic resistance bacteria . Bacteria and fungi are able to form a microbial biofilm, which can damage the human health with pathogenic effects such as allergies or infections.…”

“…[4][5][6] On the other hand, microbial contamination has increasingly threatened human health with the increasing appearance of antibiotic resistance bacteria. 7,8 Bacteria and fungi are able to form a microbial biofilm, which can damage the human health with pathogenic effects such as allergies or infections. Polymeric materials for medical applications often require antibacterial properties, which have been achieved by the incorporation of particles with antimicrobial activity.…”