Electrospun nanofibers have been used as wound dressings to protect skin from infection and promote wound healing. In this study, we developed polyvinylpyrrolidone (PVP)/silicon dioxide (SD) composite nanofibers for the delivery of probiotic Saccharomyces cerevisiae (SC), which potentially aids in wound healing. PVP/SD composite nanofibers were optimized through electrospinning, and bead-free nanofibers with an average diameter of 624.7 ± 99.6 nm were fabricated. Next, SC, a wound-healing material, was loaded onto the PVP/SD composite nanofibers. SC was encapsulated in nanofibers, and nanofibers were prepared using SC, PVP, SD, water, and ethanol in a ratio of 3:4:0.1:4.8:1.2. The formation of smooth nanofibers with protrusions around SC was confirmed using SEM. Nanofiber dressing properties were physicochemically and mechanically characterized by evaluating SEM, DSC, XRD, and FTIR images, tensile strength, and elongation at break. Additionally, a release test of active substances was performed. The absence of interactions between SC, PVP, and SD was confirmed through physicochemical evaluation, and SEM images showed that the nanofiber dressing contained SC and had a porous structure. It also showed a 100% release of SC within 30 min. Overall, our study showed that SC-loaded PVP/SD composite nanofibers prepared using the electrospinning method are promising wound dressings.

Uveitis comprises a cluster of intraocular inflammatory disorders characterized by uncontrolled autoimmune responses and excessive oxidative stress leading to vision loss worldwide. In the present study, curcumin (CUR) was conjugated with polyvinylpyrrolidone (PVP) to form PVP-CUR nanoparticles with significantly elevated solubility and outstanding multiple radical scavenging abilities. In vitro studies revealed that PVP-CUR nanoparticles markedly mitigated oxidative stress and reduced apoptosis in a H2O2-induced human retinal pigment epithelial cell line (ARPE-19) and promoted phenotypic polarization from M1 to M2 in an LPS-induced human microglial cell line (HMC3). Further in vivo studies demonstrated the prominent therapeutic effects of PVP-CUR nanoparticles on experimental autoimmune uveitis (EAU), which relieved clinical and pathological progression, improved perfusion and tomographic manifestations of retinal vessels, and reduced blood-retinal barrier (BRB) leakage; these effects may be mediated by mitigating oxidative stress and attenuating macrophage/microglia-elicited inflammation. Notably, treatment with PVP-CUR nanoparticles was shown to regulate metabolite alterations in EAU rats, providing novel insights into the underlying mechanisms involved. Additionally, the PVP-CUR nanoparticles showed great biocompatibility in vivo. In summary, our study revealed that PVP-CUR nanoparticles may serve as effective and safe nanodrugs for treating uveitis and other oxidative stress- and inflammation-related diseases.

To develop a submucosal injection material with sustained submucosal lifting for endoscopic submucosal dissection (ESD), this study designed and prepared a novel composite thermosensitive hydrogel system with high pH chitosan-polyvinylpyrrolidone-β-glycerophosphate (HpHCS-PVP-GP). HpHCS improved the injectability of the hydrogels and retained the rapid gelation ability at low concentrations. The modification of PVP significantly improved the stability of low-temperature hydrogel precursor solutions and the integrity of hydrogels formed at 37 °C through hydrogen bonds between PVP and HpHCS. A mathematical model was established using response surface methodology (RSM) to evaluate the synergistic effect of HpHCS, GP, and PVP concentrations on gelation time. This RSM model and submucosal lifting evaluation using in vitro pig esophageal models were used to determine the optimal formula of HpHCS-PVP-GP hydrogels. Although the higher PVP concentration (5 % (w/v)) prolonged gelation time, it improved hydrogel mechanical strength, resulting in better submucosal lifting performance. The experiments of Bama mini pigs showed that the heights of the cushions elevated by the HpHCS-5%PVP-GP hydrogel remained about 80 % 1 h after injection. Repeated injections were avoided, and the hydrogel had no cytotoxicity after electric cutting. Therefore, the HpHCS-PVP-GP thermosensitive hydrogel might be a promising submucosal injection material for ESD.

Increased antineoplastic drug concentrations in wastewater stem from ineffective treatment plants and increased usage. Although microrobots are promising for pollutant removal, they face hurdles in developing a superstructure with superior adsorption capabilities, biocompatibility, porosity, and pH stability. This study focused on adjusting the PVP concentration from 0.05 to 0.375 mM during synthesis to create a favorable CMOC structure for drug absorption. Lower PVP concentrations (0.05 mM) yielded a three-dimensional nanoflower structure of CaMoO4 and CuS nanostructures, whereas five-fold concentrations (0.25 mM) produced a porous structure with a dense CuS core encased in a transparent CaMoO4 shell. The magnetically movable and pH-stable COF@CMOC microrobot, achieved by attaching CMOC to cobalt ferrite (CoF) NPs, captured doxorubicin efficiently, with up to 57 % efficiency at 200 ng/mL concentration for 30 min, facilitated by electrostatic interaction, hydrogen bonding, and pore filling of DOX. The results demonstrated that DOX removal through magnetic motion showed superior performance, with an estimated improvement of 57% compared to stirring conditions (17 %). A prototype PDMS microchannel system was developed to study drug absorption and microrobot recovery. The CaMoO4 shell of the microrobots exhibited remarkable robustness, ensuring long-lasting functionality in harsh wastewater environments and improving biocompatibility while safeguarding the CuS core from degradation. Therefore, microrobots are a promising eco-friendly solution for drug extraction. These microrobots show promise for the selective removal of doxorubicin from contaminated wastewater.

Background: Povidone, a synthetic polymer commonly used in various products such as antiseptics, cosmetics, and medications, has been associated with allergic reactions, including anaphylaxis. Despite its widespread use, cases of povidone-induced anaphylaxis, especially in children, are under-recognized. This case report aims to highlight the importance of considering povidone allergy in pediatric patients presenting with anaphylaxis. Case Presentation: We describe a 3-year-old boy who experienced anaphylaxis following the application of povidone-iodine antiseptic solution to a leg wound. He presented with generalized urticaria, angioedema, dyspnea, and cough. Prompt diagnosis and management were initiated in the emergency department. He experienced the second anaphylaxis with povidone-containing eye drops prescribed during an ophthalmology visit. Conclusions: Povidone allergy should be considered in pediatric patients presenting with anaphylaxis, especially those with idiopathic reactions or multiple drug allergies. Clinicians should emphasize patient education on label reading and the provision of adrenaline autoinjectors to prevent life-threatening reactions associated with povidone exposure.

The co-administration of curcumin and hesperetin might be beneficial in terms of neuroprotective activity; therefore, in this study, we attempted to develop a fixed-dose formulation comprising these two compounds in an amorphous state. The aim of obtaining an amorphous state was to overcome the limitations of the low solubility of the active compounds. First, we assessed the possibility of using popular sweeteners (erythritol, xylitol, and sorbitol) as plasticizers to reduce the glass transition temperature of PVP K30 to prepare the polymer-excipient blends, which allowed the preparation of amorphous solid dispersions via hot-melt extrusion at a temperature below the original glass transition of PVP K30. Erythritol proved to be the superior plasticizer. Then, we focused on the development of fixed-dose amorphous solid dispersions of curcumin and hesperetin. Powder X-ray diffraction and thermal analysis confirmed the amorphous character of dispersions, whereas infrared spectroscopy helped to assess the presence of intermolecular interactions. The amorphous state of the produced dispersions was maintained for 6 months, as shown in a stability study. Pharmaceutical parameters such as dissolution rate, solubility, and in vitro permeability through artificial membranes were evaluated. The best improvement in these features was noted for the dispersion, which contained 15% of the total content of the active compounds with erythritol used as the plasticizer.

Peripheral nerve injuries (PNI) impact millions of individuals in the United States, prompting thousands of nerve repair procedures annually. Nerve conduits (NC) are commonly utilized to treat nerve injuries under 3 cm but larger gaps still pose a challenge for successful peripheral nerve regeneration (PNR) and functional recovery. This is partly attributed to the absence of bioactive agents such as stem cells or growth factors in FDA-approved conduits due to safety, harvesting, and reproducibility concerns. Therefore, curcumin, a bioactive phytochemical, has emerged as a promising alternative bioactive agent due to its ability to enhance PNR and overcome said challenges. However, its hydrophobicity and rapid degradation in aqueous solutions are considerable limitations. In this work, a nanoscale delivery platform with tannic acid (TA) and polyvinylpyrrolidone (PVP) was developed to encapsulate curcumin for increased colloidal and chemical stability. The curcumin nanoparticles (CurNPs) demonstrate significantly improved stability in water, reduced degradation rates, and controlled release kinetics when compared to free curcumin. Further, cell studies show that the CurNP is biocompatible when introduced to neuronal cells (SH-SY5Y), rat Schwann cells (RSC-S16), and murine macrophages (J774 A.1) at 5 μM, 5 μM, and 10 μM of curcumin, respectively. As a result of these improved physicochemical properties, confocal fluorescence microscopy revealed superior delivery of curcumin into these cells when in the form of CurNPs compared to its free form. A hydrogen peroxide-based oxidative stress study also demonstrated the CurNP\'s potential to protect J774 A.1 cells against excessive oxidative stress. Overall, this study provides evidence for the suitability of CurNPs to be used as a bioactive agent in NC applications.

The use of targeted drug delivery systems, including those based on selective absorption by certain receptors on the surface of the target cell, can lead to a decrease in the minimum effective dose and the accompanying toxicity of the drug, as well as an increase in therapeutic efficacy. A fullerene C60 conjugate (FA-PVP-C60) with polyvinylpyrrolidone (PVP) as a biocompatible spacer and folic acid (FA) as a targeting ligand for tumor cells with increased expression of folate receptors (FR) was obtained. Using 13C NMR spectroscopy, FT-IR, UV-Vis spectrometry, fluorometry and thermal analysis, the formation of the conjugate was confirmed and the nature of the binding of its components was established. The average particle sizes of the conjugate in aqueous solutions and cell culture medium were determined using dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA). The FA-PVP-C60 showed antiradical activity against •DPPH, •OH and O2•-, but at the same time, it was shown to generate 1O2. It was found that the conjugate in the studied concentration range (up to 200 μg/mL) is non-toxic in vitro and does not affect the cell cycle. To confirm the ability of the conjugate to selectively accumulate through folate-mediated endocytosis, its uptake into cells was analyzed by flow cytometry and confocal microscopy. It was shown that the conjugate is less absorbed by A549 cells with low FR expression than by HeLa, which has a high level of expression of this receptor.

Polyvinylpyrrolidone (PVP) is a synthetic polymer that holds significance in various fields such as biomedical, medical, and electronics, due to its biocompatibility and exceptional dielectric properties. Electrospinning is the most commonly used tool to fabricate fibers because of its convenience and the wide choice of parameter optimization. Various parameters, including solution molarity, flow rate, voltage, needle gauge, and needle-to-collector distance, can be optimized to obtain the desired morphology of the fibers. Although PVP is commercially available in various molecular weights, PVP with a molecular weight of 130,000 g/mol is generally considered to be the easiest PVP to fabricate fibers with minimal challenges. However, the fiber diameter in this case is usually in the micron regime, which limits the utilization of PVP fibers in fields that require fiber diameters in the nano regime. Generally, PVP with a lower molecular weight, such as 10,000 g/mol and 55,000 g/mol, is known to present challenges in fiber preparation. In the current study, parameter optimization for PVP possessing molecular weights of 10,000 g/mol and 55,000 g/mol was carried out to obtain nanofibers. The electrospinning technique was utilized for fiber fabrication by optimizing the above-mentioned parameters. SEM analysis was performed to analyze the fiber morphology, and quantitative analysis was performed to correlate the effect of parameters on the fiber morphology. This research study will lead to various applications, such as drug encapsulation for sustained drug release and nanoparticles/nanotubes encapsulation for microwave absorption applications.

Antimicrobial coatings provide protection against microbes colonization on surfaces. This can prevent the stabilization and proliferation of microorganisms. The ever-increasing levels of microbial resistance to antimicrobials are urging the development of alternative types of compounds that are potent across broad spectra of microorganisms and target different pathways. This will help to slow down the development of resistance and ideally halt it. The development of composite antimicrobial coatings (CACs) that can host and protect various antimicrobial agents and release them on demand is an approach to address this urgent need. In this work, new CACs based on microsized hybrids of calcium carbonate (CaCO3) and silver nanoparticles (AgNPs) were designed using a drop-casting technique. Polyvinylpyrrolidone and mucin were used as additives. The CaCO3/AgNPs hybrids contributed to endowing colloidal stability to the AgNPs and controlling their release, thereby ensuring the antibacterial activity of the coatings. Moreover, the additives PVP and mucin served as a matrix to (i) control the distribution of the hybrids, (ii) ensure mechanical integrity, and (iii) prevent the undesired release of AgNPs. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) techniques were used to characterize the 15 μm thick CAC. The antibacterial activity was determined against Escherichia coli, methicillin-resistant Staphylococcus aureus (MRSA), and Pseudomonas aeruginosa, three bacteria responsible for many healthcare infections. Antibacterial performance of the hybrids was demonstrated at concentrations between 15 and 30 μg/cm2. Unloaded CaCO3 also presented bactericidal properties against MRSA. In vitro cytotoxicity tests demonstrated that the hybrids at bactericidal concentrations did not affect human dermal fibroblasts and human mesenchymal stem cell viability. In conclusion, this work presents a simple approach for the design and testing of advanced multicomponent and functional antimicrobial coatings that can protect active agents and release them on demand.