Electrosprayed PCL/calcium silicate/vancomycin coating on laser-textured AZ80 magnesium alloy: Corrosion resistance and cellular response

• Laser-treated AZ80 increased Rct from 2.52 to 13.8 kΩ·cm² through β-phase dissolution. • L-PCL/CaSi coating exhibited great long-term capacitive stability (∼70°) within 5 days in SBF, effectively retarding corrosion in comparison with the bare and laser-only samples. • Water contact angle decreased from 87.6° to 39.7° (55% reduction), increasing hydrophilicity and facilitating osteoblast adhesion. • Pole figure analysis revealed approximately 65% reduction in intensity of basal {002} texture after laser treatment, which resulted in more randomized grain orientation and reduced micro-galvanic corrosion susceptibility. • L-PCL/CaSi/VAN had 93.86% MG63 cell viability, 78% superior to that of untreated AZ80 (52.72%) and approximately 15% higher compared to L-PCL. • The integration of laser-induced dissolution of the β-phase and bioactive electrosprayed coating led to substantial enhancement in corrosion resistance, cytocompatibility, and antibacterial activity, and hence L-PCL/CaSi/VAN-coated AZ80 is a potential biodegradable orthopedic implant material. Magnesium (Mg) alloys like AZ80 are potential materials for biodegradable orthopedic implants because of their bone-like mechanical properties and biodegradability, but their poor corrosion resistance in physiological fluids hinders their practical use. In this study, an optimized laser-textured AZ80 surface previously reported to dissolve β-Mg₁₇Al₁₂ phases was coated with an electrosprayed polycaprolactone/calcium silicate/vancomycin (L-PCL/CaSi/VAN) layer to evaluate corrosion resistance, cytocompatibility, and drug delivery. FE-SEM surface analysis revealed smooth L-PCL droplets (∼6.5 µm) and larger calcium silicate-loaded droplets (∼15.5 µm), while EDS revealed incorporation of Ca (1.01 wt%) and Si (0.08 wt%) into the polymer matrix upon successful loading. ATR-FTIR ensured PCL chemical stability with minor shifts. Wettability was also significantly improved, as the water contact angle decreased from 87.6° to 39.7°, corresponding to a 55% relative reduction in value, and improved potential osteoblast adhesion. Pole figure analysis confirmed that laser processing reduced the basal {002} texture intensity, leading to a more randomized crystallographic orientation. Electrochemistry confirmed that laser treatment improved the charge transfer resistance (Rct) from 2.52 kΩ·cm² to 13.8 kΩ·cm², a 448% enhancement. At the same time, the L-PCL/CaSi coating had superior capacitive stability (∼70°) within 5 days in simulated body fluid, indicating delayed corrosion. Biological assays revealed L-PCL/CaSi/VAN to have achieved around 93.86% MG63 cell viability, an improvement of 78% compared to untreated AZ80. FE-SEM observed extensive osteoblast coverage with long filopodia on the hybrid coating. Vancomycin release was triphasic, with less than 5% within the first 5 hours, 70.51% at 12 hours, and 98.67% at 72 hours, offering both instant antibacterial protection and prolonged therapeutic delivery. In short, the synergy of optimized laser surface texturing, wettability enhancement, bioactive nanocomposite coating, and controlled release of drugs enormously augmented the corrosion resistance, cytocompatibility, and antibacterial property of AZ80 such that L-PCL/CaSi/VAN is a very promising next-generation biodegradable orthopedic implant material.