Abstract: Compositions comprising RIP are advantageously formulated in compositions allowing sustained release and protection from degradation, and improved therapeutic efficacy. To that end, RIP compositions may be delivered to the skin or mucosal membranes as a salve or the like. Alternatively or additionally, RIP compositions may be administered in polymeric nanoparticle carriers, which may be biodegradable. Such formulations are compatible with oral administration. The nanoparticle may accommodate a composition comprising a RIP and at least one other antimicrobial agent, e.g., an antibiotic or an antimicrobial peptide. The nanoparticle further may comprise a coating or moiety, such as an antibody or fragment thereof, to assist in cell targeting.

Abstract: RNAIII-inhibiting peptide (RIP) advantageously treats or reduces the risk of biofilm formation on implanted bone cement, thus reducing the possibility of sustained chemotherapy, hospitalization, or surgical removal of the bone cement. Avoiding sustained chemotherapy reduces the risk of inducing antibiotic resistance. Accordingly, RIP can be used with antibiotics that otherwise would be reserved as a last resort, such as vancomycin. RIP potentiates the activity of vancomycin, minimizing the risk of inducing vancomycin-resistance. The present invention thus is expected to prolong significantly the effectiveness of antibiotics of last resort for the treatment of periprosthetic infection.