Electrochemical Fabrication and Characterization of Pectin Hydrogel Composite Materials for Bone Tissue Repair

Development of coatings with tailored surface properties that enhance bone growth is crucial to enhancing the life span of load bearing implants. Bioactive ceramic-polysaccharide hydrogel composite materials are attractive for this application due to their chemical similarity to human bone at the nanoscale. Equally important is the creation of advanced coating processing techniques that can be easily upscaled for mass manufacturing. Toward this aim, we developed an electrochemical fabrication technique for the simple and rapid processing of composite pectin hydrogels. This technique used polygalacturonic acid (PGA) combined with anodic electrophoretic deposition (EPD) to fabricate composite hydrogels, which contained bioactive particles such as TiO2, hydroxyapatite, and bioactive glass. Another key finding was the ability of PGA to facilitate rapid fabrication of antibacterial coatings for infection prevention using the antibiotic tetracycline. We proposed a mechanism of deposition and proved our hypothesis using Fourier transform infrared spectroscopy. To evaluate the suitability of our coatings for bone tissue repair, comprehensive surface characterization was conducted, including scanning electron microscopy, X-ray diffraction, water contact angle measurements, and cell metabolism assays. Surface characterization results revealed that our PGA composite films exhibit a desirable combination of surface chemistry and morphology, which was achieved in one processing step. Furthermore, PGA hydrogel coatings supported cell adhesion and proliferation, demonstrating that our technique is an attractive strategy for rapid surface modification of metallic implants.