Molded polymer-coated composite bone void filler improves tobramycin controlled release kinetics

Area of Science:

• Biomaterials Science
• Orthopedic Surgery
• Infectious Diseases

Background:

• Device-related orthopedic infections, particularly in revision joint replacements, pose significant clinical challenges and economic burdens.
• Current treatments for these infections are often limited, necessitating innovative solutions like antibiotic-releasing bone void fillers (BVF).

Purpose of the Study:

• To report improvements in the fabrication and scalability of a novel antibiotic-releasing polycaprolactone-calcium carbonate/phosphate ceramic composite BVF.
• To demonstrate the ability to tailor drug release kinetics for extended antibiotic delivery at bactericidal concentrations.

Main Methods:

• A solvent-free, molten-cast fabrication process was employed for the BVF composite.
• Mechanical properties were assessed and compared to existing BVFs.
• In vitro drug release kinetics and time-kill studies were conducted to evaluate antimicrobial efficacy.

Main Results:

• The new fabrication process yielded a homogeneous BVF composite with mechanical properties comparable to existing materials.
• The BVF composite demonstrated extended tobramycin release, maintaining bactericidal activity for up to 10 weeks in vitro.
• Tobramycin-releasing composite fragments effectively inhibited Staphylococcus aureus growth over 48 hours at high bacterial inoculums.

Conclusions:

• The customizable, solvent-free fabricated BVF offers a promising solution for preventing and treating orthopedic infections.
• This polymer-inorganic biomaterial possesses potential osseointegrative and osteoconductive properties, combined with crucial antimicrobial protection.
• The developed BVF technology holds potential for improving outcomes in patients requiring bone void fillers in orthopedic procedures.