An Overview of the Antimicrobial Activity of Polymeric Nanoparticles Against Enterobacteriaceae

Nano-sized warriors: zinc chromium vanadate nanoparticles as a dual solution for eradicating waterborne enterobacteriaceae and fighting cancer

The revolution of biomedical applications has opened new avenues for nanotechnology. Zinc Chromium vanadate nanoparticles (VCrZnO4 NPs) have emerged as an up-and-coming candidate, with their exceptional physical and chemical properties setting them apart. In this study, a one-pot solvothermal method was employed to synthesize VCrZnO4 NPs, followed by a comprehensive structural and morphological analysis using a variety of techniques, including X-Ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, Energy-dispersive X-ray, and X-ray photoelectron spectroscopy. These techniques confirmed the crystallinity of the NPs. The VCrZnO4 NPs were tested for their antibacterial activity against primary contaminants such as Enterobacteriaceae, including Shigella flexneri, Salmonella cholerasis, and Escherichia coli, commonly found in hospital settings, using the broth dilution technique. The results indicated a stronger antibacterial activity of VCrZnO4 NPs against Shigella and Salmonella than E. coli. Electron microscopy showed that the NPs caused severe damage to the bacterial cell wall and membrane, leading to cell death. In addition, the study evaluated the anticancer activities of the metal complexes in vitro using colorectal cancer cells (HCT-116) and cervical cancer cells (HELA), along with non-cancer cells and human embryonic kidney cells (HEK-293). A vanadium complex demonstrated efficient anticancer effects with half-inhibitory concentrations (IC₅₀) of 38.50+3.50 g/mL for HCT-116 cells and 42.25+4.15 g/mL for HELA cells. This study highlights the potential of Zinc Chromium vanadate nanoparticles as promising candidates for antibacterial and anticancer applications. Various advanced characterization techniques were used to analyze the properties of nanomaterials, which may help develop more effective and safer antibacterial and anticancer agents in the future.

Photodynamic potential of hexadecafluoro zinc phthalocyanine in nanostructured lipid carriers: physicochemical characterization, drug delivery and antimicrobial effect against Candida albicans

This study aims to develop and characterize NCL loaded with ZnF16Pc (Pc) for application in antimicrobial photodynamic therapy. For the development of the NLC, the fusion-emulsification technique followed by sonication was applied. NLC and Pc-NLC were characterized in terms of mean diameter (Dm.n), polydispersity index (PdI), zeta potential (ZP), encapsulation efficiency (%EE), transmission electron microscopy (TEM), differential scanning (DSC), photobleaching and singlet oxygen generation in cellular systems (SOSG), and in vitro release assays performed by the beaker method, using dialysis membranes. Cell viability was performed by colony forming units (CFU/mL). The mean size of NLC and Pc-NLC was 158 nm ± 1.49 to 161.80 nm and showed PdI < 0.3 and ZP between -17.8 and -19.9, and stable during storage time (90 days). The TEM presented spherical particles, the Pc-NLC promoted the encapsulation of 75.57% ± 0.58. DSC analysis confirmed that there was no incompatibility between Pc and NLC. The analysis of the photodegradation profile proved to be photostable after encapsulation and this corroborates the data obtained by SOSG. In vitro release showed controlled and prolonged release. PDT Pc-NLC exhibited greater antifungal effect against C. albicans (3 log10 reduction) than Pc-NLC without light (1 log10 reduction). NLC can be an alternative to the application of Pc and improve the effect during PDT treatment.

Potential Application of Cephalosporins Carried in Organic or Inorganic Nanosystems Against Gram-negative Pathogens

Cephalosporins are β-lactam antibiotics, classified into five generations and extensively used in clinical practice against infections caused by Gram-negative pathogens, including Enterobacteriaceae and P. aeruginosa. Commercially, conventional pharmaceutical forms require high doses to ensure clinical efficacy. Additionally, β-lactam resistance mechanisms, such as the production of enzymes (called extended-spectrum β-lactamases) and the low plasma half-life of these antibiotics have been challenging in clinical therapy based on the use of cephalosporins. In this context, its incorporation into nanoparticles, whether organic or inorganic, is an alternative to temporally and spatially control the drug release and improve its pharmacokinetic and pharmacodynamic limitations. Considering this, the present review unites the cephalosporins encapsulated into organic and inorganic nanoparticles against resistant and nonresistant enterobacteria. We divide cephalosporin generation into subtopics in which we discuss all molecules approved by regulatory agencies. In addition, changes in the side chains at positions R1 and R2 of the central structure of cephalosporins for all semisynthetic derivatives developed were discussed and presented, as the changes in these groups are related to modifications in pharmacological and pharmacokinetic properties, respectively. Ultimately, we exhibit the advances and differences in the release profile and in vitro activity of cephalosporins incorporated in different nanoparticles.

Curcumin-Loaded Micelles Dispersed in Ureasil-Polyether Materials for a Novel Sustained-Release Formulation

Vulvovaginal candidiasis (VVC) is a vulvar/vaginal infection that affects approximately 75% of women worldwide. The current treatment consists of antimicrobials with hepatotoxic properties and high drug interaction probabilities. Therefore, this study aimed to develop a new treatment to VVC based on micelles containing curcumin (CUR) dispersed in a ureasil-polyether (U-PEO) hybrid. The physical-chemical characterization was carried out in order to observe size, shape, crystallinity degree and particle dispersion in the formulation and was performed by dynamic light scattering (DLS), scanning electron microscopy (SEM), X-ray diffraction (XRD) and through in vitro release study. The results of DLS and SEM exhibited micelles with 35 nm, and encapsulation efficiency (EE) results demonstrated 100% of EE to CUR dispersed in the U-PEO, which was confirmed by the DRX. The release results showed that CUR loaded in U-PEO is 70% released after 10 days, which demonstrates the potential application of this material in different pharmaceutical forms (ovules and rings), and the possibility of multidose based on a single application, suggesting a higher rate of adherence.