Preclinical animal study demonstrates that local hydrogel-delivered cefazolin clears spinal infection in rats, indicating a safer alternative to long-term systemic antibiotics.
Key Points
Evaluate the therapeutic efficacy and safety of a localized gelatin hydrogel microsphere system delivering cefazolin (GM-CEZ) in a rat model of pyogenic spondylodiscitis.
Characterized GM-CEZ in vitro for degradation kinetics, sustained release, and antimicrobial activity.
Tested in vivo efficacy in rats infected with bioluminescent methicillin-susceptible Staphylococcus aureus, comparing single local GM-CEZ (1 mg GM, 250 μg/kg CEZ) against local CEZ alone and 28-day systemic CEZ (25 mg/kg/day) using optical imaging, micro-computed tomography, and immunohistochemistry.
Assessed systemic toxicity with blood tests and local intervertebral disc cytotoxicity using TUNEL staining.
A single local injection of GM-CEZ significantly reduced bacterial burden and white blood cell counts at day 7 and decreased bone destruction at day 28 compared to local CEZ and systemic CEZ (all p < 0.05).
GM-CEZ significantly increased CD31 and smooth muscle actin immunopositivity compared to both local and systemic CEZ groups (all p < 0.05), demonstrating enhanced vascularization and tissue repair.
Safety evaluations confirmed no significant myelotoxicity, nephrotoxicity, or local cytotoxicity associated with GM-CEZ administration.