Role of bioactive magnetic nanoparticles in the prevention of wound pathogenic biofilm formation using smart nanocomposites

BACKGROUND

Biofilm formation and its resistance to various antibiotics is a serious health problem in the treatment of wound infections. An ideal wound dressing should have characteristics such as protection of wound from microbial infection, suitable porosity (to absorb wound exudates), proper permeability (to maintain wound moisture), nontoxicity, and biocompatibility. Although silver nanoparticles (AgNPs) have been investigated as antimicrobial agents, their limitations in penetrating into the biofilm, affecting their efficiency, have consistently been an area for further research.

RESULTS

Consequently, in this study, the optimal amounts of natural and synthetic polymers combination, along with AgNPs, accompanied by iron oxide nanoparticles (IONPs), were utilized to fabricate a smart bionanocomposite that meets all the requirements of an ideal wound dressing. Superparamagnetic IONPs (with the average size of 11.8 nm) were synthesized through co-precipitation method using oleic acid to improve their stability. It was found that the addition of IONPs to bionanocomposites had a synergistic effect on their antibacterial and antibiofilm properties. Cytotoxicity assay results showed that nanoparticles does not considerably affect eukaryotic cells compared to prokaryotic cells. Based on the images obtained by confocal laser scanning microscopy (CLSM), significant AgNPs release was observed when an external magnetic field (EMF) was applied to the bionanocomposites loaded with IONPs, which increased the antibacterial activity and inhibited the formation of biofilm significantly.

CONCLUSION

These finding indicated that the nanocomposite recommended can have an efficient properties for the management of wounds through prevention and treatment of antibiotic-resistant biofilm.

Preclinical Testing of a Novel Niclosamide Stearate Prodrug Therapeutic (NSPT) Shows Efficacy Against Osteosarcoma

Therapeutic advances for osteosarcoma have stagnated over the past several decades, leading to an unmet clinical need for patients. The purpose of this study was to develop a novel therapy for osteosarcoma by reformulating and validating niclosamide, an established anthelminthic agent, as a niclosamide stearate prodrug therapeutic (NSPT). We sought to improve the low and inefficient clinical bioavailability of oral dosing, especially for the relatively hydrophobic classes of anticancer drugs. Nanoparticles were fabricated by rapid solvent shifting and verified using dynamic light scattering and UV-vis spectrophotometry. NSPT efficacy was then studied in vitro for cell viability, cell proliferation, and intracellular signaling by Western blot analysis; ex vivo pulmonary metastatic assay model; and in vivo pharmacokinetic and lung mouse metastatic model of osteosarcoma. NSPT formulation stabilizes niclosamide stearate against hydrolysis and delays enzymolysis; increases circulation in vivo with t _1/2 approximately 5 hours; reduces cell viability and cell proliferation in human and canine osteosarcoma cells in vitro at 0.2-2 μmol/L IC₅₀; inhibits recognized growth pathways and induces apoptosis at 20 μmol/L; eliminates metastatic lesions in the ex vivo lung metastatic model; and when injected intravenously at 50 mg/kg weekly, it prevents metastatic spread in the lungs in a mouse model of osteosarcoma over 30 days. In conclusion, niclosamide was optimized for preclinical drug delivery as a unique prodrug nanoparticle injected intravenously at 50 mg/kg (1.9 mmol/L). This increased bioavailability of niclosamide in the blood stream prevented metastatic disease in the mouse. This chemotherapeutic strategy is now ready for canine trials, and if successful, will be targeted for human trials in patients with osteosarcoma.

Niclosamide repositioning for treating cancer: Challenges and nano-based drug delivery opportunities

Drug repositioning may be defined as a process when new biological effects for known drugs are identified, leading to recommendations for new therapeutic applications. Niclosamide, present in the Model List of Essential Medicines, from the World Health Organization, has been used since the 1960s for tapeworm infection. Several preclinical studies have been shown its impressive anticancer effects, which led to clinical trials for colon and prostate cancer. Despite high expectations, proof of efficacy and safety are still required, which are associated with diverse biopharmaceutical challenges, such as the physicochemical properties of the drug and its oral absorption, and their relationship with clinical outcomes. Nanostructured systems are innovative drug delivery strategies, which may provide interesting pharmaceutical advantages for this candidate. The aim of this review is to discuss challenges involving niclosamide repositioning for cancer diseases, and the opportunities of therapeutic benefits from nanosctrutured system formulations containing this compound.

Bimetallic Fe-Cu Nanocomposites on Sand Particles for the Inactivation of Clinical Isolates and Point-of-Use Water Filtration

Bimetallic Fe-Cu nanocomposites with an average size of 26.4 ± 4.7 nm were prepared on the surface of fine sand particles by modified coprecipitation and the chemical reduction method and were applied as an in vitro broad spectrum antimicrobial agent and recyclable hand-held water filter to sieve bacteria and metals. The size of the nanocomposites could be further reduced to 11.8 ± 1.6 nm when prepared after ball milling the sand particles, keeping the antimicrobial property intact. The results showed that the chemical nature and morphology of the nanocomposites had a great effect on both Gram-positive and Gram-negative bacteria with a minimum inhibitory concentration of 10.6 μg/mL and 13.8 μg/mL of copper, whereas the minimum bactericidal concentration was found to be 15.9 μg/mL and 21.2 μg/mL. The nanocomposites exhibited antimicrobial activity against multidrug-resistant bacteria as well as fungus isolated from different human biological samples like blood, urine, pus, and wound swabs. The nanocomposites were also capable of filtering a wide range bacteria like Acinetobacter baumannii, Escherichia coli, Salmonella typhi, Bacteroides fragilis, Salmonella paratyphi, Shigella dysenteriae, and Enterococcus faecalis, which are predominantly responsible for waterborne diseases. Further, the nanocomposites were used for the removal of hazardous metals like nickel, zinc, and lead. Leaching of copper and iron from the nanocomposites was within the permissible limit as per Bureau of Indian Standards (BIS) for Drinking Water (IS-10500-2012, second revision) as well as the International Standards for Drinking Water.