Immobilised teicoplanin does not demonstrate antimicrobial activity against Staphylococcus aureus

Area of Science:

• Biomaterials Science
• Infectious Diseases
• Orthopedic Surgery

Background:

• Developing effective antibacterial bone biomaterial coatings is crucial for orthopedics, dentistry, and veterinary medicine.
• Immobilizing antibiotics onto biomaterial surfaces presents significant challenges in achieving stable and functional conjugation.
• Teicoplanin, a macrocyclic glycopeptide antibiotic, is a potential candidate due to its cell wall activity and known stability in immobilized states.

Purpose of the Study:

• To investigate the feasibility of functionalizing titanium (Ti) with polydopamine to immobilize teicoplanin for antibacterial bone biomaterial coatings.
• To assess the stability and antibacterial efficacy of immobilized teicoplanin on titanium surfaces.
• To evaluate the potential of commercially available teicoplanin stationary phases in killing bacteria.

Main Methods:

• Functionalization of titanium surfaces with polydopamine.
• Attempted immobilization of teicoplanin onto the functionalized titanium.
• Assessment of teicoplanin-titanium interaction and stability in the presence of phosphate.
• Testing the antibacterial activity of a commercial teicoplanin stationary phase against staphylococci.

Main Results:

• Direct immobilization of teicoplanin onto titanium oxide surfaces was unavoidable, despite using a polydopamine platform.
• While the interaction between teicoplanin and titanium was robust, phosphate ions caused antibiotic loss.
• A commercial teicoplanin stationary phase, capable of binding bacterial cell wall components, failed to exhibit antibacterial activity against staphylococci.

Conclusions:

• Covalent immobilization of teicoplanin and other glycopeptide antibiotics onto bone biomaterials is strongly discouraged due to lack of efficacy.
• The tested commercial teicoplanin stationary phase demonstrated binding capabilities but lacked bactericidal function.
• Further research should explore alternative strategies for developing effective antibacterial bone biomaterials, as direct immobilization of teicoplanin appears unviable.