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

Abstract

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.

Tuning the Biointerface: Low-Temperature Surface Modification Strategies for Orthopedic Implants to Enhance Osteogenic and Antimicrobial Activity

“…47,48 Moreover, these hierarchically structured coatings increased the wettability of the surface, which has also been demonstrated to promote osseointegration. In vitro characterization revealed that these coatings supported both cell proliferation 47,48 and differentiation 48 of osteoblast-like cells. However, a disadvantage of multiscale, hydrophilic surfaces is that they may also promote adhesion and proliferation of bacterial cells.…”

“…46−48 EPD offers the user a high degree of control over both surface topography and chemistry as well as the ability to deposit uniform films on intricate substrates. 47,48 Coating topography can be altered with ease by varying parameters such as electric field strength, current density, and deposition time. 45 Furthermore, it enables simultaneous deposition of functional macromolecules, inorganic particles, and polymers in a single fabrication step, which circumvents the limitations related to electrochemical anodization.…”

“…EPD is an electrochemical processing technique that utilizes an external electric field to deposit films from a charged, stable, colloidal precursor. , Under the influence of electrophoresis, the charged materials migrate to the substrate surface, where they deposit due to particle coagulation or local variation in the pH. − EPD offers the user a high degree of control over both surface topography and chemistry as well as the ability to deposit uniform films on intricate substrates. , Coating topography can be altered with ease by varying parameters such as electric field strength, current density, and deposition time . Furthermore, it enables simultaneous deposition of functional macromolecules, inorganic particles, and polymers in a single fabrication step, which circumvents the limitations related to electrochemical anodization.…”

“…As mentioned previously, surfaces that contain features across multiple length scales have also been found to be beneficial for cell adhesion and proliferation . In addition to tailoring the surface chemistry with bioactive particles and polymers, deposition voltage was varied to modify the surface morphology with nano and microscale features in one fabrication step. , Moreover, these hierarchically structured coatings increased the wettability of the surface, which has also been demonstrated to promote osseointegration. In vitro characterization revealed that these coatings supported both cell proliferation , and differentiation of osteoblast-like cells.…”

“…In addition to tailoring the surface chemistry with bioactive particles and polymers, deposition voltage was varied to modify the surface morphology with nano and microscale features in one fabrication step. , Moreover, these hierarchically structured coatings increased the wettability of the surface, which has also been demonstrated to promote osseointegration. In vitro characterization revealed that these coatings supported both cell proliferation , and differentiation of osteoblast-like cells. However, a disadvantage of multiscale, hydrophilic surfaces is that they may also promote adhesion and proliferation of bacterial cells.…”