RESUMO
A major factor contributing to the failure of orthopedic and orthodontic implants is post-surgical infection. Coating metallic implant surfaces with anti-microbial agents has shown promise but does not always prevent the formation of bacterial biofilms. Furthermore, breakdown of these coatings within the human body can cause release of the anti-microbial drugs in an uncontrolled or unpredictable fashion. In this study, we used a calcium alginate and calcium phosphate cement (CPC) hydrogel composite as the base material and enriched these hydrogels with the anti-microbial drug, gentamicin sulfate, loaded within a halloysite nanotubes (HNTs). Our results demonstrate a sustained and extended release of gentamicin from hydrogels enriched with the gentamicin-loaded HNTs. When tested against the gram-negative bacteria, the hydrogel/nanoclay composites showed a pronounced zone of inhibition suggesting that anti-microbial doped nanoclay enriched hydrogels can prevent the growth of bacteria. The release of gentamicin sulfate for a period of five days from the nanoclay-enriched hydrogels would supply anti-microbial agents in a sustained and controlled manner and assist in preventing microbial growth and biofilm formation on the titanium implant surface. A pilot study, using mouse osteoblasts, confirmed that the nanoclay enriched surfaces are also cell supportive as osteoblasts readily, proliferated and produced a type I collagen and proteoglycan matrix.
RESUMO
Post-operative complications due to infections are the most common problems that occur following dental and orthopedic implant surgeries and bone repair procedures. Preventing post-surgical infections is therefore a critical need that current polymethylmethacrylate (PMMA) bone cement fail to address. Calcium phosphate cements (CPCs) are unique in their ability to crystallize calcium and phosphate salts into hydroxyapatite (HA) and hence is naturally osteoconductive. Due to its low mechanical strength its use in implant fixation and bone repair is limited to non-load bearing applications. The present work describes a new and novel antibiotic-doped clay nanotube CPC composite with enhanced mechanical properties as well as sustained release properties.
