Cytocompatibility of pH-sensitive, chitosan-coated Fe3O4 nanoparticles in gynecological cells

A magnetic-guided nano-antibacterial platform for alternating magnetic field controlled vancomycin release in staphylococcus aureus biofilm eradication

Bacterial resilience within biofilms, rendering them up to 1000 times more resistant to antibiotic drugs, poses a formidable challenge. This study introduces a targeted biofilm eradication strategy, termed "target-penetration-killing-eradication", implemented through magnetic micro-robotic technology. Specifically, we present the development of a magnetic-guided nano-antibacterial platform designed for alternating magnetic field (AMF) controlled vancomycin release in the eradication of Staphylococcus aureus biofilms. To address the issue of premature vancomycin release in physiological conditions, we employed a temperature-sensitive linking agent, 4,4'-azobis(4-cyano valeric acid), facilitating the conjugation of vancomycin onto Fe3O4/CS nanocomposites, resulting in the novel construct Fe3O4@CS-ACVA-VH. The release mechanism adheres to first-order kinetics and Fickian diffusion, with each 10-min AMF treatment releasing approximately 8.4 ± 1.1% of vancomycin. The potency of vancomycin in the release solution was similar to that of the original drug (MIC: 7.4 ± 3.5 vs. 5.6 μg/mL). Fe3O4@CS-ACVA-VH exhibited sustained antibacterial efficacy, inhibiting bacterial growth for four consecutive days and preventing the formation of bacterial biofilms on its surface. Contact-inhibition bacterial activity of Fe3O4@CS-ACVA-VH against S. aureus was 0.046875 mg/mL. Conceptually validating our approach, we emphasize Fe3O4@CS-ACVA-VH's exceptional ability to penetrate S. aureus biofilms under static magnetic field attraction. Furthermore, the nano-platform offers the unique advantage of on-demand vancomycin release through alternating magnetic field stimulation, effectively clearing a larger biofilm area. This multifunctional nano-platform demonstrates magnetic-guided biofilm penetration followed by controlled vancomycin release, presenting a promising strategy for enhanced biofilm eradication.

Catalytic hydrolysis of agar using magnetic nanoparticles: optimization and characterization

BACKGROUND

Agar is used as a gelling agent that possesses a variety of biological properties; it consists of the polysaccharides agarose and porphyrin. In addition, the monomeric sugars generated after agar hydrolysis can be functionalized for use in biorefineries and biofuel production. The main objective of this study was to develop a sustainable agar hydrolysis process for bioethanol production using nanotechnology. Peroxidase-mimicking Fe3O4-MNPs were applied for agar degradation to generate agar hydrolysate-soluble fractions amenable to Saccharomyces cerevisiae and Escherichia coli during fermentation.

RESULTS

Fe3O4-MNP-treated (Fe3O4-MNPs, 1 g/L) agar exhibited 0.903 g/L of reducing sugar, which was 21-fold higher than that of the control (without Fe3O4-MNP-treated). Approximately 0.0181% and 0.0042% of ethanol from 1% of agar was achieved using Saccharomyces cerevisiae and Escherichia coli, respectively, after process optimization. Furthermore, different analytical techniques (FTIR, SEM, TEM, EDS, XRD, and TGA) were applied to validate the efficiency of Fe3O4-MNPs in agar degradation.

CONCLUSIONS

To the best of our knowledge, Fe3O4-MNP-treated agar degradation for bioethanol production through process optimization is a simpler, easier, and novel method for commercialization.