Enhanced antibacterial activity of 3D-printed niosome-curcumin/ceftizoxime scaffolds against drug-resistant pathogens

Hospital-acquired infections caused by multidrug-resistant (MDR) pathogens such as Methicillin-resistant Staphylococcus aureus (MRSA) and Carbapenem-resistant Klebsiella pneumoniae (CRKP) are a major health concern. In this study, ceftizoxime (CEF) and curcumin (CUR) were co-encapsulated into niosome nanoparticles (using thin-film hydration), and then embedded into a 3D-printed gelatin-alginate scaffold (Nio-CUR/CEF@SC). The Nio-CUR/CEF@SC were characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR). The antibacterial activity was assessed using MIC, time-kill, and disc diffusion assays, while anti-biofilm activity was evaluated using crystal violet (CV) and minimum biofilm eradication concentration (MBEC) assays. Gene expression of virulence and resistance genes was measured using qRT-PCR, and cytotoxicity was tested via MTT assay on HFF cells. The Nio-CUR/CEF@SC system exhibited high encapsulation efficiency (CUR:78%; CEF: 80%), uniform nanoscale size (208–308 nm), and sustained dual-drug release over 72 h. This formulation reduced MIC values against MRSA and CRKP to 0.25–1 µg/mL (over 64-fold improvement vs. free drugs), produced large inhibition zones (up to 31.5 mm), and achieved strong time-kill and anti-biofilm effects (> 2 log₁₀ CFU/mL reduction). It also led to significant downregulation of MRSA ((hla, hlb, pvl)_ and CRKP (blaTEM, blaCTXM, blaOXA-48) virulence/resistance genes and showed > 90% viability on normal fibroblasts at effective doses. This study demonstrates that 3D-printed Nio-CUR/CEF@SC is an effective drug delivery system for the treatment of MRSA and CRKP infections in vitro. The engineered nanocarrier has potential for further research on infection therapies and offers a promising approach to combat drug-resistant pathogens.