Effect of trabecular metal on the elution of gentamicin from Palacos cement

Progress of antibiotic-loaded bone cement in joint arthroplasty

Bone cement, consisting of polymethyl methacrylate, is a bioinert material used for prothesis fixation in joint arthroplasty. To treat orthopedic infections, such as periprosthetic joint infection, antibiotic-loaded bone cement (ALBC) was introduced into clinical practice. Recent studies have revealed the limitations of the antibacterial effect of ALBC. Moreover, with the increase in high infection risk patients and highly resistant microbes, more researches and modification of ALBC are required. This paper reviewed latest findings about ALBC for most popular and destructive pathogens, summarized the influence of antibiotic kind, drug dosage, application method, and environment towards characteristic of ALBC. Subsequently, new cement additives and clinical applications of ALBC in joint arthroplasty were also discussed.

Self-defensive antimicrobial biomaterial surfaces

Self-defensive biomaterial surfaces are being developed in order to mitigate infection associated with tissue-contacting biomedical devices. Such infection occurs when microbes colonize the surface of a device and proliferate into a recalcitrant biofilm. A key intervention point centers on preventing the initial colonization. Incorporating antimicrobials within a surface coating can be very effective, but the traditional means of antimicrobial delivery by continuous elution can often be counterproductive. If there is no infection, continuous elution creates conditions that promote the development of resistant microbes throughout the patient. In contrast, a self-defensive coating releases antimicrobial only when and only where there is a microbial challenge to the surface. Otherwise, the antimicrobial remains sequestered within the coating and does not contribute to the development of resistance. A self-defensive surface requires a local trigger that signals the microbial challenge. Three such triggers have been identified as: (1) local pH lowering; (2) local enzyme release; and (3) direct microbial-surface contact. This short review highlights the need for self-defensive surfaces in the general context of the device-infection problem and then reviews key biomaterials developments associated with each of these three triggering mechanisms.