Synthesis of antibiotic-modified silica nanoparticles and their use as a controlled drug release system with antibacterial properties

Geldanaycin-encapsulated magnetic nanoparticle for isolation of myosin in proteomics

The grafting of a drug molecule, i.e., geldanamycin (GA) onto polyethyleneimine (PEI)-coated magnetic nanoparticle produces a novel composite, GA@Fe3O4-NH2. The composite is confirmed by characterizations with FT-IR, Raman, SEM, EDS, VSM and TEM. Due to the high binding-affinity of GA with myosin heavy chain (MYH), GA@Fe3O4-NH2 exhibits excellent adsorption performance towards myosin. Consequently, a solid-phase extraction procedure is established for highly efficient and selective separation of myosin from pig heart extract. At pH 6.0, an adsorption efficiency of 97.1 % is achieved for treating 100 μg mL-1 myosin (0.1 mL) with 0.1 mg GA@Fe3O4-NH2 as adsorbent. The adsorption behavior of myosin onto GA@Fe3O4-NH2 fits Langmuir model, corresponding to a theoretical adsorption capacity of 518.1 mg g-1. The adsorbed myosin can be readily recycled by the SDS solution (1 %, m/m) with an elution efficiency of 91.8 %. According to circular dichroism spectroscopy, the conformational changes of myosin during adsorption and elution are reversible. For practical application, myosin is successfully isolated from the pig left ventricular protein extract with GA@Fe3O4-NH2, and SDS-PAGE and LC-MS/MS showed that myosin had high purity and a total of 716 proteins could be identified. Significantly, Geldamycin-encapsulated magnetic nanoparticle for the separation of myosin well exploits the potential of the nanomaterials modified by drug molecules in the separation and purification of target proteins.

In Vitro Antimicrobial Studies of Mesoporous Silica Nanoparticles Comprising Anionic Ciprofloxacin Ionic Liquids and Organic Salts

The combination of active pharmaceutical ingredients in the form of ionic liquids or organic salts (API-OSILs) with mesoporous silica nanoparticles (MSNs) as drug carriers can provide a useful tool in enhancing the capabilities of current antibiotics, especially against resistant strains of bacteria. In this publication, the preparation of a set of three nanomaterials based on the modification of a MSN surface with cholinium ([MSN-Chol][Cip]), 1-methylimidazolium ([MSN-1-MiM][Cip]) and 3-picolinium ([MSN-3-Pic][Cip]) ionic liquids coupled with anionic ciprofloxacin have been reported. All ionic liquids and functionalized nanomaterials were prepared through sustainable protocols, using microwave-assisted heating as an alternative to conventional methods. All materials were characterized through FTIR, solution ¹H NMR, elemental analysis, XRD and N₂ adsorption at 77 K. The prepared materials showed no in vitro cytotoxicity in fibroblasts viability assays. The minimum inhibitory concentration (MIC) for all materials was tested against Gram-negative K. pneumoniae and Gram-positive Enterococcus spp., both with resistant and sensitive strains. All sets of nanomaterials containing the anionic antibiotic outperformed free ciprofloxacin against resistant and sensitive forms of K. pneumoniae, with the prominent case of [MSN-Chol][Cip] suggesting a tenfold decrease in the MIC against sensitive strains. Against resistant K. pneumoniae, a five-fold decrease in the MIC was observed for all sets of nanomaterials compared with neutral ciprofloxacin. Against Enterococcus spp., only [MSN-1-MiM][Cip] was able to demonstrate a slight improvement over the free antibiotic.

Polyphosphazene-Based Biomaterials for Biomedical Applications

Recently, synthetic polymers have attracted great interest in the field of biomedical science. Among these, polyphosphazenes (PPZs) are regarded as one of the most promising materials, due to their structural flexibility and biodegradability compared to other materials. PPZs have been developed through numerous studies. In particular, multi-functionalized PPZs have been proven to be potential biomaterials in various forms, such as nanoparticles (NPs) and hydrogels, through the introduction of various functional groups. Thus, PPZs have been applied for the delivery of therapeutic molecules (low molecular weight drugs, genes and proteins), bioimaging, phototherapy, bone regeneration, dental liners, modifiers and medical devices. The main goal of the present review is to highlight the recent and the most notable existing PPZ-based biomaterials for aforementioned applications, with future perspectives in mind.

Nanoparticle-Containing Wound Dressing: Antimicrobial and Healing Effects

The dressings containing nanoparticles of metals and metal oxides are promising types of materials for wound repair. In such dressings, biocompatible and nontoxic hydrophilic polymers are used as a matrix. In the present review, we take a look at the anti-microbial effect of the nanoparticle-modified wound dressings against various microorganisms and evaluate their healing action. A detailed analysis of 31 sources published in 2021 and 2022 was performed. Furthermore, a trend for development of modern antibacterial wound-healing nanomaterials was shown as exemplified in publications starting from 2018. The review may be helpful for researchers working in the areas of biotechnology, medicine, epidemiology, material science and other fields aimed at the improvement of the quality of life.

Effects of Methoxyfenozide-Loaded Fluorescent Mesoporous Silica Nanoparticles on Plutella xylostella (L.) (Lepidoptera: Plutellidae) Mortality and Detoxification Enzyme Levels Activities

The diamond back moth, Plutella xylostella, causes severe damage at all crop stages, beside its rising resistance to all insecticides. The objective of this study was to look for a new control strategy such as application of insecticide-loaded carbon dot-embedded fluorescent mesoporous silica nanoparticles (FL-SiO₂ NPs). Two different-sized methoxyfenozide-loaded nanoparticles (Me@FL-SiO₂ NPs-70 nm, Me@FL-SiO₂ NPs-150 nm) were prepared, with loading content 15% and 16%. Methoxyfenozide was released constantly from Me@FL-SiO₂ NPs only at specific optimum pH 7.5. The release of methoxyfenozide from Me@FL-SiO₂ NPs was not observed other than this optimum pH, and therefore, we checked and controlled a single release condition to look out for the different particle sizes of insecticide-loaded NPs. This pH-responsive release pattern can find potential application in sustainable plant protection. Moreover, the lethal concentration of the LC₅₀ value was 24 mg/L for methoxyfenozide (TC), 14 mg/L for Me@FL-SiO₂ NPs-70 nm, and 15 mg/L for Me@FL-SiO₂ NPs-150 nm after 72 h exposure, respectively. After calculating the LC₅₀, the results predicted that Me@FL-SiO₂ NPs-70 nm and Me@FL-SiO₂ NPs-150 nm exhibited better insecticidal activity against P. xylostella than methoxyfenozide under the same concentrations of active ingredient applied. Moreover, the activities of detoxification enzymes of P. xylostella were suppressed by treatment with insecticide-loaded NPs, which showed that NPs could also be involved in reduction of enzymes. Furthermore, the entering of FL-SiO₂ NPs into the midgut of P. xylostella was confirmed by confocal laser scanning microscope (CLSM). For comparison, P. xylostella under treatment with water as control was also observed under CLSM. The control exhibited no fluorescent signal, while the larvae treated with FL-SiO₂ NPs showed strong fluorescence under a laser excitation wavelength of 448 nm. The reduced enzyme activities as well as higher cuticular penetration in insects indicate that the nano-based delivery system of insecticide could be potentially applied in insecticide resistance management.