Humic acid–loaded pHEMA cryogels as an antimicrobial platform for MRSA-infected diabetic foot: in vitro, in vivo, and molecular docking studies

Abstract Diabetic foot infections complicated by methicillin-resistant Staphylococcus aureus (MRSA) remain a major clinical challenge due to impaired wound healing and limited effectiveness of conventional antibiotic therapies. In this study, humic acid (HA)–loaded p(HEMA-GMA) cryogels were successfully synthesized and evaluated as a multifunctional wound dressing platform for the treatment of MRSA-infected diabetic foot wounds. The structural and chemical characteristics of the cryogels were confirmed by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The HA-loaded cryogels exhibited a high swelling ratio of approximately 97%, indicating excellent exudate absorption capacity. Biocompatibility and hemocompatibility assessments demonstrated that the cryogels were safe for biomedical applications. In vitro antibacterial studies revealed that HA2-p(HEMA-GMA) achieved 93.9 ± 0.85% inhibition of MRSA growth based on time-kill kinetics. SEM analyses further confirmed the disruption of MRSA biofilm structures and severe deformation of bacterial morphology. In vivo therapeutic efficacy was evaluated using an MRSA-infected diabetic rat foot wound model, where treatment with HA2-p(HEMA-GMA) resulted in a significant wound area reduction of 94.5 ± 0.7%. Molecular docking analysis provided preliminary insights into potential interactions, showing a favorable binding affinity of humic acid toward the 2 × 3 F protein, with a docking score of − 8.358 kcal/mol. Overall, these findings indicate that HA-loaded p(HEMA-GMA) cryogels effectively modulate the wound microenvironment, suppress bacterial proliferation, and accelerate wound healing under diabetic and infected conditions. This multifunctional cryogel system represents a promising alternative therapeutic strategy for the management of MRSA-infected diabetic foot wounds.