Controlled Delivery of Vancomycin via Charged Hydrogels

Area of Science:

• Biomaterials Science
• Infectious Disease Research
• Drug Delivery Systems

Background:

• Surgical site infections (SSI) pose a significant risk in orthopedic surgery, often necessitating further interventions and prolonging recovery.
• Current antimicrobial strategies for SSI prophylaxis face limitations including systemic toxicity, bacterial resistance, and poor patient compliance.
• Localized, controlled-release antibiotic formulations are needed to improve efficacy and minimize adverse effects.

Purpose of the Study:

• To engineer biocompatible oligo(poly(ethylene glycol)fumarate)/sodium methacrylate (OPF/SMA) charged copolymers as hydrogel matrices for localized antibiotic delivery.
• To characterize the vancomycin loading capacity and release kinetics of the developed OPF/SMA hydrogels.
• To evaluate the antimicrobial efficacy of vancomycin released from the hydrogel against methicillin-resistant Staphylococcus aureus (MRSA).

Main Methods:

• Development and characterization of OPF/SMA charged copolymers as hydrogel matrices.
• Loading of vancomycin into the hydrogel, assessing time- and charge-dependency.
• Measurement of vancomycin release kinetics over time.
• Assessment of the antimicrobial activity of released vancomycin against a clinical MRSA strain.

Main Results:

• OPF/SMA hydrogels demonstrated efficient vancomycin loading (over 500 μg/mg), dependent on time and charge.
• Vancomycin release kinetics were modulated by copolymer negative charge, with controlled release observed over four days.
• Released vancomycin retained antimicrobial activity equivalent to stock vancomycin against MRSA.
• Controlled release achieved low initial release rates (33.7% in 6 hours, <80% in 24 hours).

Conclusions:

• Engineered OPF/SMA hydrogels show promise as effective carriers for localized antibiotic delivery.
• This localized delivery system can potentially improve prophylaxis of surgical site infections.
• The developed hydrogels offer a strategy to enhance antibiotic treatment effectiveness while mitigating systemic side effects.