Vancomycin containing PLLA/β-TCP controls MRSA in vitro

Area of Science:

• Biomaterials Science
• Orthopedic Surgery
• Infectious Diseases

Background:

• Osteomyelitis caused by Methicillin-resistant Staphylococcus aureus (MRSA) presents significant treatment challenges, often necessitating surgical intervention and extended antibiotic therapy.
• Current local antibiotic delivery systems utilize bioceramics or polymers, each with distinct advantages and disadvantages regarding antibiotic release and bone integration.
• A novel vancomycin-loaded poly-l-lactic acid/β-tricalcium phosphate (PLLA/β-TCP) composite was engineered to optimize antibiotic elution and promote bone regeneration.

Purpose of the Study:

• To characterize the physical properties and antibiotic release profile of the developed vancomycin-containing PLLA/β-TCP composite.
• To evaluate the in vitro biocompatibility of the composite, specifically its capacity to support cell adhesion, proliferation, and mineralization.
• To assess the efficacy of the composite in delivering vancomycin at inhibitory concentrations against MRSA.

Main Methods:

• Vancomycin-containing (VC) and vancomycin-free (VUC) composites were fabricated using PLLA, β-TCP, and chloroform, with some VC composites further dip-coated with PLLA (CVC) to modulate release.
• Composite characteristics including pore structure, size, volume, density, and surface area were meticulously analyzed.
• In vitro assessments included vancomycin release kinetics, bioactivity assays, and evaluation of mesenchymal stem cell (MSC) and Saos type 2 cell adhesion, proliferation, and mineralization.

Main Results:

• The dip-coated CVC composites exhibited specific pore characteristics (3.5 ± 1.9 μm), volume, density, and surface area.
• Controlled vancomycin release was observed, with 63.1% released on Day 1 and 91.9% by Week 6.
• Mesenchymal stem cells and Saos type 2 cells demonstrated successful adhesion and proliferation on the composite materials within 3 and 7 days.

Conclusions:

• The vancomycin-containing PLLA/β-TCP composites, particularly after dip-coating, effectively release antibiotics in inhibitory concentrations.
• The composite materials demonstrated biocompatibility, supporting crucial cellular functions like adhesion, proliferation, and mineralization in vitro.
• These findings suggest that vancomycin-loaded PLLA/β-TCP composites hold potential for managing MRSA osteomyelitis, warranting further in vivo validation.