2026-10-11T08:09:54Z https://api.figshare.com/v2/oai

oai:figshare.com:article/32641224 2026-10-01T16:24:51Z portal_1172 item_type_8 month_year_10_2026

Multifunctional polycaprolactone/graphene oxide nanocomposite coatings for metal implants Maloba Ketchen Tabi (24169866) PUREID: 640729673 Graphene oxide poly(caprolactone) magnesium electrochemical impedance spectroscopy corrosion biodegradable Nanocomposite coating 316L Sainless Steel degradation drug release photothermal therapy Biodegradable implants for bone repair have gained significant interest over the past decade. Magnesium (Mg) is a promising candidate due to its biocompatibility, non-toxicity, and mechanical properties similar to human bone, reducing stress-shielding effects. However, the rapid degradation of Mg alloys (e.g., AZ31, AZ91, WE43) remains a challenge, affecting their long-term performance in bone repair applications.<br><br>This study aims to develop a multifunctional nanocomposite coating composed of polycaprolactone (PCL) and graphene oxide (GO) to control Mg alloy (AZ31) degradation while enabling drug delivery and photothermal therapy. The initial phase involved coating 316L stainless steel (316L SS) as a stable demonstrator substrate. PCL/GO coatings with GO concentrations of 0.02 wt%, 0.1 wt%, and 0.2 wt% were developed. Potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) results demonstrated that a low GO concentration (0.02 wt%) significantly improved corrosion resistance. However, higher GO concentrations led to agglomeration, compromising coating integrity. Corrosion resistance was also found to increase with coating thickness.<br><br>Further, PCL/GO coatings were engineered for drug release, where drug-laden layers were incorporated beneath the coating. The release kinetics followed the Korsmeyer-Peppas model, with release rates controllable by adjusting coating thickness. The optimized coating was then applied to pre-treated Mg alloy (AZ31), exhibiting similar corrosion resistance and drug release trends as seen with 316L SS.<br><br>Additionally, biocompatibility and photothermal properties were evaluated. GO enhanced stem cell survival at 0.02 wt% and 0.1 wt% but reduced viability at 0.2 wt%, indicating dose dependence. Photothermal therapy using MG-63 osteosarcoma cells confirmed that GO-mediated laser-induced heating effectively killed cancer cells in a concentration-dependent manner.<br><br>This study highlights the potential of PCL/GO nanocomposite coatings as a multifunctional platform for enhanced Mg-based implants in bone repair and cancer therapy. 2026-10-01T16:24:51Z Text Thesis 10.17034/32641224.v1 https://figshare.com/articles/thesis/Multifunctional_polycaprolactone_graphene_oxide_nanocomposite_coatings_for_metal_implants/32641224 All Rights Reserved