Enhanced Corrosion Resistance and Mechanical Durability of the Composite PLGA/CaP/Ti Scaffolds for Orthopedic Implants

• Published in: Polymers 2024-03, Vol.16 (6), p.826
• Main Authors: Prosolov, Konstantin A, Komarova, Ekaterina G, Kazantseva, Ekaterina A, Luginin, Nikita A, Kashin, Alexander D, Uvarkin, Pavel V, Sharkeev, Yurii P
• Format: Article
• Language: English
• Subjects: Adhesive strength; Analysis; Arc deposition; Biocompatibility; Biodegradation; Biomedical engineering; Calcium phosphate; Calcium phosphates; Chemical properties; Coatings; Composite materials; Corrosion currents; Corrosion rate; Corrosion resistance; Drug delivery systems; Electrolytes; Glycolic acid; Hydroxyapatite; Immersion coating; Lactic acid; Mechanical properties; Orthopaedic implants; Orthopedic implants; Orthopedics; Oxidation; Peel tests; Polymers; Scanning electron microscopy; Scratch tests; Substrates; Surgical implants; Tensile tests; Titanium; Transplants & implants
• ISSN: 2073-4360; 2073-4360
• DOI: 10.3390/polym16060826

In addressing the challenge of enhancing orthopedic implants, 3D porous calcium phosphate (CaP) coatings on titanium (Ti) substrates modified with poly(lactic-co-glycolic acid) (PLGA) were proposed. CaP coatings on Ti were deposited using the ultrasonic-assisted micro-arc oxidation (UMAO) method, followed by modification with PLGA through a dip coating process at concentrations of 5%, 8%, and 10%. The addition of PLGA significantly improved adhesive-cohesive strength according to the scratch test, while PLGA to CaP adhesion was found to be not less than 8.1 ± 2.2 MPa according to the peel test. Tensile testing showed a typical fracture of CaP coatings and mechanisms of brittle fracture. Corrosion resistance, assessed via gravimetric and electrochemical methods in 0.9% NaCl and PBS solutions, revealed PLGA's substantial reduction in corrosion rates, with the corrosion current decreasing by two orders of magnitude even for the 5% PLGA/CaP/Ti sample. Also, the PLGA layer significantly enhanced the impedance modulus by two orders of magnitude, indicating a robust barrier against corrosion at all PLGA concentrations. Higher PLGA concentrations offered even greater corrosion resistance and improved mechanical properties. This research underscores the potential of using CaP- and PLGA-modified coatings to extend the life and functionality of orthopedic implants, addressing a significant challenge in biomedical engineering.