Using an Engineered Galvanic Redox System to Generate Positive Surface Potentials that Promote Osteogenic Functions

Abstract

Successful osseointegration of orthopaedic and orthodontic implants is dependent on a competition between osteogenesis and bacterial contamination on the implant–tissue interface. Previously, by taking advantage of the highly interactive capabilities of silver nanoparticles (AgNPs), we effectively introduced an antimicrobial effect to metal implant materials using an AgNP/poly(DL-lactic-co-glycolic acid) (PLGA) coating. Although electrical forces have been shown to promote osteo-genesis, creating practical materials and devices capable of harnessing these forces to induce bone regeneration remains challenging. Here, we applied galvanic reduction–oxidation (redox) principles to engineer a nanoscale galvanic redox system between AgNPs and 316L stainless steel alloy (316L-SA). Characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, atomic force microscopy, Kelvin probe force microscopy, and contact angle measurement, the surface properties of the yield AgNP/PLGA-coated 316L-SA (SNPSA) material presented a significantly increased positive surface potential, hydrophilicity, surface fractional polarity, and surface electron accepting/donating index. Importantly, in addition to its bactericidal property, SNPSA’s surface demonstrated a novel osteogenic bioactivity by promoting peri-implant bone growth. This is the first report describing the conversion of a normally deleterious galvanic redox reaction into a biologically beneficial function on a biomedical metal material. Overall, this study details an innovative strategy to design multifunctional biomaterials using a controlled galvanic redox reaction, which has broad applications in material development and clinical practice.

A Multifunctional Antibacterial and Osteogenic Nanomedicine: QAS-Modified Core-Shell Mesoporous Silica Containing Ag Nanoparticles

“…Plaque biofilms are known to be the initiating factors for oral diseases such as periodontitis or peri-implantitis, which cause infections and eventually alveolar bone defects [ 28 ]. At present, basic clinical treatment can effectively block the progress of infection, but improving bone restoration in the infected area must rely on the implantation of effective bone grafting materials to retain the three-dimensional space needed for new bone formation [ 29 , 30 ]. More than 80% of microbial infections are associated with biofilm formation [ 31 ].…”

Therapeutic Applications of Antimicrobial Silver-Based Biomaterials in Dentistry

“…Zhang et al first created a nanoscale galvanic redox system between AgNPs and 316L stainless steel alloy, which promoted peri-implant osteogenesis and antimicrobial activity. 147

Figure 9 AgBM-modified implants promote antimicrobial property and bone formation. ( A ) Schematic illustration of antibacterial surface modification of Ti implants for preventing implant-associated infection.

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The Impact of Dental Implant Surface Modifications on Osseointegration and Biofilm Formation

“…In particular, those surfaces that can stimulate the growth of osteoblasts and/or their production of growth factors and cytokines will positively influence osseointegration. For example, by building up a nanoscale galvanic reduction−oxidation (redox) system on the metal implant surface, Zhang et al introduced novel osteogenic bioactivity to the implant for promoting peri-implant bone growth [ 15 ].…”