Intermolecular Interactions and the Release Pattern of Electrospun Curcumin-Polyvinyl(pyrrolidone) Fiber

Multifactorial evaluation of an ultra-fast process for electrospinning of recycled expanded polystyrene to manufacture high-efficiency membranes for nanoparticle air filtration

The increased production of polystyrene waste has led to the need to find efficient ways to dispose of it. One possibility is the use of solid waste to produce filter media by the electrospinning technique. The aim of this work was to develop an ultra-fast electrospinning process applied to recycled polystyrene, with statistical evaluation of the influence of polymeric solution parameters (polymer concentration and percentage of DL-limonene) and process variables (flow rate, voltage, and type of support) on nanoparticle collection efficiency, air permeability, and fiber diameter. An extensive characterization of the materials and evaluation of the morphology of the fibers was also carried out. It was found that recycled expanded polystyrene could be used in electrospinning to produce polymeric membranes. The optimized condition that resulted in the highest nanoparticle collection efficiency was a polymer concentration of 13.5%, percentage of DL-limonene of 50%, voltage of 25 kV, and flow rate of 1.2 mL/h, resulting in values of 99.97 ± 0.01%, 2.6 ± 0.5 × 10-13 m2, 0.19 Pa-1, and 708 ± 176 nm for the collection efficiency of nanoparticles in the range from 6.38 to 232.9 nm, permeability, quality factor, and mean fiber diameter, respectively. All the parameters were found to influence collection efficiency and fiber diameter. The use of DL-limonene, a natural solvent, provided benefits including increased collection efficiency and decreased fiber size. In addition, the electrostatic filtration mechanism was evaluated using the presence of a copper grid as a support for the nanofibers. The findings demonstrated that an electrospinning time of only 5 min was sufficient to obtain filters with high collection efficiencies and low pressure drops, opening perspectives for the application of polystyrene waste in the development of materials with excellent characteristics for application in the area of atmospheric pollution mitigation.

In vitro and in vivo assessment of curcumin-quercetin loaded multi-layered 3D-nanofibroporous matrix prepared by solution blow-spinning for full-thickness burn wound healing

Burn wounds (BWs) cause impairment of native skin tissue and may cause significant microbial infections that demand immediate care. Curcumin (Cur) and quercetin (Que) exhibit antimicrobial, hemocompatibility, ROS-scavenging, and anti-inflammatory properties. However, its instability, water insolubility, and low biological fluid absorption render it challenging to sustain local Cur and Que doses at the wound site. Therefore, to combat these limitations, we employed blow-spinning and freeze-drying to develop a multi-layered, Cur/Que-loaded gelatin/chitosan/PCL (GCP-Q/C) nanofibroporous (NFP) matrix. Morphological analysis of the NFP-matrix using SEM revealed a well-formed multi-layered structure. The FTIR and XRD plots demonstrated dual-bioactive incorporation and scaffold polymer interaction. Additionally, the GCP-Q/C matrix displayed high porosity (82.7 ± 2.07 %), adequate pore size (∼121 μm), enhanced water-uptake ability (∼675 % within 24 h), and satisfactory biodegradation. The scaffolds with bioactives had a long-term release, increased antioxidant activity, and were more effective against gram-positive (S. aureus) and gram-negative (E. coli) bacteria than the unloaded scaffolds. The in vitro findings of GCP-Q/C scaffolds showed promoted L929 cell growth and hemocompatibility. Additionally, an in vivo full-thickness BW investigation found that an implanted GCP-Q/C matrix stimulates rapid recuperation and tissue regeneration. In accordance with the findings, the Gel/Ch/PCL-Que/Cur NFP-matrix could represent an effective wound-healing dressing for BWs.

Synthesis and characterization of nitrogen-doped-MWCNT@cobalt oxide for nerve agent simulant detection

Organophosphorus nerve agents are toxic compounds that disrupt neuromuscular transmission by inhibiting the neurotransmitter enzyme, acetylcholinesterase, leading to rapid death. A hybrid composite was synthesized using a hydrothermal process for the early detection of dimethyl methyl phosphonate (DMMP), a simulant of the G-series nerve agent, sarin. Quartz crystal microbalance (QCM) and surface acoustic wave (SAW) sensors were used as detectors. Nitrogen-doped multiwalled carbon nanotubes (N-MWCNTs), cobalt oxide (Co3O4), and N-MWCNT@Co3O4 were compared to detect DMMP concentrations of 25-150 ppm. At 25 ppm, the differential frequencies (Δf) of the N-MWCNT, Co3O4, and N-MWCNT@Co3O4 sensors were 5.8, 2.3, and 99.5 Hz, respectively. The selectivity results revealed a preference for the DMMP rather than potential interference. The coefficients of determination (R2) of the N-MWCNT, Co3O4, and N-MWCNT@Co3O4 sensors for detecting 25-150 ppm DMMP were 0.983, 0.986, and 0.999, respectively. The response times of the N-MWCNT, Co3O4, and N-MWCNT@Co3O4 sensors for detecting 100 ppm DMMP were 25, 27, and 34 s, respectively, while the corresponding recovery times were 85, 105, and 181 s. The repeatability results revealed the reversible adsorption and desorption phenomena for the fixed DMMP concentration of 100 ppm. These unique findings show that synthesized materials can be used to detect organophosphorus nerve agents.

Thymol, a Monoterpenoid within Polymeric Iodophor Formulations and Their Antimicrobial Activities

Antimicrobial resistance (AMR) poses an emanating threat to humanity's future. The effectiveness of commonly used antibiotics against microbial infections is declining at an alarming rate. As a result, morbidity and mortality rates are soaring, particularly among immunocompromised populations. Exploring alternative solutions, such as medicinal plants and iodine, shows promise in combating resistant pathogens. Such antimicrobials could effectively inhibit microbial proliferation through synergistic combinations. In our study, we prepared a formulation consisting of Aloe barbadensis Miller (AV), Thymol, iodine (I2), and polyvinylpyrrolidone (PVP). Various analytical methods including SEM/EDS, UV-vis, Raman, FTIR, and XRD were carried out to verify the purity, composition, and morphology of AV-PVP-Thymol-I2. We evaluated the inhibitory effects of this formulation against 10 selected reference strains using impregnated sterile discs, surgical sutures, gauze bandages, surgical face masks, and KN95 masks. The antimicrobial properties of AV-PVP-Thymol-I2 were assessed through disc diffusion methods against 10 reference strains in comparison with two common antibiotics. The 25-month-old formulation exhibited slightly lower inhibitory zones, indicating changes in the sustained-iodine-release reservoir. Our findings confirm AV-PVP-Thymol-I2 as a potent antifungal and antibacterial agent against the reference strains, demonstrating particularly strong inhibitory action on surgical sutures, cotton bandages, and face masks. These results enable the potential use of the formulation AV-PVP-Thymol-I2 as a promising antimicrobial agent against wound infections and as a spray-on contact-killing agent.

The Impact of Various Poly(vinylpyrrolidone) Polymers on the Crystallization Process of Metronidazole

In this paper, we propose one-step synthetic strategies for obtaining well-defined linear and star-shaped polyvinylpyrrolidone (linPVP and starPVP). The produced macromolecules and a commercial PVP K30 with linear topology were investigated as potential matrices for suppressing metronidazole (MTZ) crystallization. Interestingly, during the formation of binary mixtures (BMs) containing different polymers and MTZ, we found that linear PVPs exhibit maximum miscibility with the drug at a 50:50 weight ratio (w/w), while the star-shaped polymer mixes with MTZ even at a 30:70 w/w. To explain these observations, comprehensive studies of MTZ-PVP formulations with various contents of both components were performed using Fourier-transform infrared spectroscopy, differential scanning calorimetry, and X-ray diffraction. The obtained results clearly showed that the polymer's topology plays a significant role in the type of interactions occurring between the matrix and MTZ. Additionally, we established that for MTZ-PVP 50:50 and 75:25 w/w BMs, linear polymers have the most substantial impact on inhibiting the crystallization of API. The star-shaped macromolecule turned out to be the least effective in stabilizing amorphous MTZ at these polymer concentrations. Nevertheless, long-term structural investigations of the MTZ-starPVP 30:70 w/w system (which is not achievable for linear PVPs) demonstrated its complete amorphousness for over one month.

Investigating the Effect of Selenium Nanoparticles on Mineral Trioxide Aggregates as a Promising Novel Dental Material

Aim

To enhance mineral trioxide aggregate high plasticity (MTA HP), a commonly used dental calcium silicate cement, by incorporating selenium nanoparticles (SeNPs) known for their antioxidant and anti-inflammatory properties. The objectives included investigating the impact of SeNPs on the setting time and chemical properties of MTA HP.

Materials and Methods

We performed a comprehensive study to formulate and profile SeNPs integrated into MTA HP. Diverse concentrations of SeNPs were introduced into MTA HP, and the commencement and culmination of the setting process were gauged employing a Gillmore needle cabinet. The chemical composition was validated using Fourier transform infrared spectroscopy with attenuated total reflectance and X-ray diffraction analysis.

Results

The incorporation of SeNPs led to remarkable improvements. Notably, SeNPs positively affected the setting time of MTA HP, with faster setting times corresponding to higher SeNPs concentrations. Chemical analyses confirmed the successful integration of SeNPs with MTA HP. These enhancements make the material may be suitable for dental applications, especially due to its accelerated setting time.

Conclusions

MTA HP incorporated with SeNPs represents a significant advancement in dental materials. Its faster setting time, combined with the antioxidant and anti-inflammatory properties of selenium, provides dental professionals with an efficient and time-saving option for complex treatments. This novel nanomaterial holds promise for improving dental procedures and patient outcomes.

Injectable systems of chitosan in situ forming composite gel incorporating linezolid-loaded biodegradable nanoparticles for long-term treatment of bone infections

The objective of the current study was to create an efficient, minimally invasive combined system comprising in situ forming hydrogel loaded with both spray-dried polymeric nanoparticles encapsulating linezolid and nanohydroxyapatite for local injection to bones or their close vicinity. The developed system was designed for a dual function namely releasing the drug in a sustained manner for long-term treatment of bone infections and supporting bone proliferation and new tissues generation. To achieve these objectives, two release sustainment systems for linezolid were optimized namely a composite in situ forming chitosan hydrogel and spray-dried PLGA/PLA solid nanoparticles. The composite, in situ forming hydrogel of chitosan was prepared using two different gelling agents namely glycerophosphate (GP) and sodium bicarbonate (NaHCO3) at 3 different concentrations each. The spray-dried linezolid-loaded PLGA/PLA nanoparticles were developed using a water-soluble carrier (PVP K30) and a lipid soluble one (cetyl alcohol) along with 3 types of DL-lactide and/or DL-lactide-co-glycolide copolymer using nano-spray-drying technique. Finally, the optimized spray-dried linezolid nanoparticles were incorporated into the optimized composite hydrogel containing nanohydroxy apatite (nHA). The combined hydrogel/nanoparticle systems displayed reasonable injectability with excellent gelation time at 37 °C. The optimum formulae sustained the release of linezolid for 7-10 days, which reveals its ability to reduce the frequency of injection during the course of treatment of bones infections and increase the patients' compliance. They succeeded to alleviate the bone infections and the associated clinical, biochemical, radiological, and histopathological changes within 2-4 weeks of injection. As to the state of art in this study and to the best of our knowledge, no such complete and systematic study on this type of combined in situ forming hydrogel loaded with spray-dried nanoparticles of linezolid is available yet in literatures.

An investigation into the effects of ink formulations of semi-solid extrusion 3D printing on the performance of printed solid dosage forms

Semi-solid extrusion (SSE) 3D printing has recently attracted increased attention for its pharmaceutical application as a potential method for small-batch manufacturing of personalised solid dosage forms. It has the advantage of allowing ambient temperature printing, which is especially beneficial for the 3D printing of thermosensitive drugs. In this study, the effects of polymeric compositions (single hydroxypropyl methylcellulose (HPMC) system and binary HPMC + polyvinylpyrrolidone (PVP) system), disintegrant (silicon oxide (SiO2)), and active pharmaceutical ingredients (tranexamic acid (TXA) and paracetamol (PAC)) on the printability of semisolid inks and the qualities of SSE printed drug-loaded tablets were investigated. Printability is defined by the suitability of the material for the process in terms of its physical properties during extrusions and post-extrusion, including rheology, solidification time, avoiding slumping, etc. The rheological properties of the inks were investigated as a function of polymeric compositions and drug concentrations and further correlated with the printability of the inks. The SSE 3D printed tablets were subjected to a series of physicochemical properties characterisations and in vitro drug release performance evaluations. The results indicated that an addition of SiO2 would improve 3D printing shape fidelity (e.g., pore area and porosity) by altering the ink rheology. The pores of HPMC + PVP + 5PAC prints completely disappeared after 12 hours of drying (pore area = 0 mm2). An addition of SiO2 significantly improved the pore area of the prints which are 3.5 ± 0.1 mm2. It was noted that the drug release profile of PAC significantly increased (p < 0.05) when additive SiO2 was incorporated in the formulation. This could be due to a significantly higher porosity of HPMC + PVP + SiO2 + PAC (70.3 ± 0.2%) compared to HPMC + PVP + PAC (47.6 ± 2.1%). It was also likely that SiO2 acted as a disintegrant speeding up the drug release process. Besides, the incorporation of APIs with different aqueous solubilities, as well as levels of interaction with the polymeric system showed significant impacts on the structural fidelity and subsequently the drug release performance of 3D printed tablets.

Towards complete photonic band gap in a high refractive index nanoparticle-doped blue phase liquid crystal

Three-dimensional (3D) photonic crystals with complete photonic band gap (PBG) are fascinating due to the possibility of controlling light in all directions. Realizing such photonic crystals is nontrivial due to symmetry requirements and associated fabrication challenges. Liquid crystalline cubic blue phases (BPs) are soft 3D photonic crystals with an incomplete PBG due to the low refractive index contrast (<0.1). The present work attempts to drive a cubic BP towards a complete PBG via a simple approach of high refractive index nanoparticle-doping. The photonic band diagrams and reflection spectra of the nanoparticle-doped BP simulated using the finite element method show an increased PBG width, a parameter that quantifies the complete PBG. The reflection spectra obtained from UV-Vis-NIR spectroscopy show an increase (by a factor of >2) in PBG width for the nanoparticle-doped BP, validating the simulations. The findings are explained based on increased refractive index contrast (∼1.4) due to the nanoparticles getting trapped in the cores of disclination lines that make up the BP lattice. The simulations also indicate effective confinement of electric field eigenmodes in the nanoparticle-doped BP leading to high attenuation of the incident light. Further, the iso-frequency contours extracted from the band diagrams exhibit self-collimation and negative refraction of light.

Guar gum-based stimuli responsive hydrogels for sustained release of diclofenac sodium

In the current study, hydrogels for the controlled release of diclofenac sodium were synthesized from graphene oxide-reinforced guar gum and poly (N-vinyl-2-pyrrolidone) using the Solution Casting Technique. Varying concentrations of 3-Glycidyloxypropyl trimethoxysilane (GLYMO) were employed for the crosslinking of hydrogels. Further, the characterization of hydrogels was carried out using different techniques such as Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction, thermal analysis and scanning electron microscope. The FTIR investigations reveals particular functionalities and development of hydrogel interfaces. While thermal analysis prophesied that, improvement in forces among hydrogel components is directly proportional to the GLYMO concentration. In-vitro biodegradation test and cell viability assay against HEK-293 cell lines confirmed their biodegradable and biocompatible nature. GPG-32 demonstrated maximum antibacterial activity against P.aeruginosa and E.coli strains. The maximum swelling 2001 % and 1814 % in distilled water were recorded for GPG (control) and GPG-8 respectively that obeyed Fick's law. Hydrogels displayed high swelling responses at pH 6 in buffer and non-buffer solutions. In 2.5 h, 88.7 % diclofenac sodium was released which was determined by UV visible spectrophotometer. In conclusion, guar gum-based non-toxic, biocompatible and biodegradable hydrogels would be a model platform for targeting inflammation and pains. Furthermore, improved mechanical and viscoelastic behavior of hydrogels could also be explored for making drug loaded dressings for wound healing applications.

Development of double crosslinked sodium alginate/chitosan based hydrogels for controlled release of metronidazole and its antibacterial activity

Double network sodium alginate/chitosan hydrogels were prepared using calcium chloride (CaCl2) and glutaraldehyde as the crosslinking agents by the ionotropic interaction method for controlled metronidazole release. The effect of polymer ratios and CaCl2 amount is investigated by the developing porosity, gel fraction, and extent of swelling in simulated physiological fluids. Interaction between the polymers with the formation of crosslinked structures, good stability, phase nature, and morphology of the hydrogels is revealed by Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, and scanning electron microscopy. A sodium alginate/chitosan hydrogel (weight ratio of 75:25) crosslinked with two percent CaCl2 is chosen for the in-situ loading of 200 mg of metronidazole. The drug release kinetics using different models show that the best-fit Korsmeyer-Peppas model suggests metronidazole release from the matrix follows diffusion and swelling-controlled time-dependent non-Fickian transport related to hydrogel erosion. This composition displays enhanced antimicrobial activity against Staphylococcus aureus and Escherichia coli.

Electrospun Nanofibers from Waste Polyvinyl Chloride Loaded Silver and Titanium Dioxide for Water Treatment Applications

The electrospun nanofiber membrane from polyvinyl chloride (PVC) waste for water treatment applications has been successfully produced. The PVC precursor solution was prepared by dissolving the PVC waste in DMAc solvent, and a centrifuge was used to separate undissolved materials from the precursor solution. Ag and TiO₂ were added to the precursor solution before the electrospinning process. We studied the fabricated PVC membranes using SEM, EDS, XRF, XRD, and FTIR to study the fiber and membrane properties. The SEM images depicted that Ag and TiO₂ addition has changed the morphology and size of fibers. The EDS images and XRF spectra confirmed the presence of Ag and TiO₂ on the nanofiber membrane. The XRD spectra showed the amorphous structure of all membranes. The FTIR result indicated that the solvent completely evaporated throughout the spinning process. The fabricated PVC@Ag/TiO₂ nanofiber membrane showed the photocatalytic degradation of dyes under visible light. The filtration test on the membrane PVC and PVC@Ag/TiO₂ depicted that the presence of Ag and TiO₂ affected the flux and separation factor of the membrane.

High-Efficiency Water Filtration by Electrospun Expanded Polystyrene Waste Nanofibers

Nanofiber membranes were successfully synthesized from expanded polystyrene (EPS) waste with the addition of poly(vinylpyrrolidone) (PVP) for water microfiltration using the electrospinning method. The EPS-based nanofiber membranes exhibited a smooth morphology and were uniform in size. The concentration of the EPS/PVP solution changed some of the physical parameters of the nanofiber membrane, such as viscosity, conductivity, and surface tension. Greater viscosity and surface tension increase the nanofiber membrane diameter, whereas the addition of PVP results in hydrophilicity. Additionally, increasing the pressure increased the flux value of each variation of the nanofiber membranes. Furthermore, the rejection value was 99.99% for all variations. Finally, the use of EPS waste for nanofiber membranes is also beneficial for decreasing the amount of EPS waste in the environment and is an alternative to the current membranes available in the market for water filtration applications.

Development of Novel Pharmaceutical Forms of the Marine Bioactive Pigment Echinochrome A Enabling Alternative Routes of Administration

Echinochrome A (EchA), a marine bioactive pigment isolated from various sea urchin species, is the active agent of the clinically approved drug Histochrome^®. EchA is currently only available in the form of an isotonic solution of its di- and tri-sodium salts due to its poor water solubility and sensitivity to oxidation. Electrospun polymeric nanofibers have lately emerged as promising drug carriers capable of improving the dissolution and bioavailability of drugs with limited water solubility. In the current study, EchA isolated from sea urchins of the genus Diadema collected at the island of Kastellorizo was incorporated in electrospun micro-/nanofibrous matrices composed of polycaprolactone and polyvinylpyrrolidone in various combinations. The physicochemical properties of the micro-/nanofibers were characterized using SEM, FT-IR, TGA and DSC analyses. The fabricated matrices exhibited variable dissolution/release profiles of EchA, as evidenced in in vitro experiments using gastrointestinal-like fluids (pH 1.2, 4.5 and 6.8). Ex vivo permeability studies using the EchA-loaded micro-/nanofibrous matrices showed an increased permeation of EchA across the duodenum barrier. The results of our study clearly show that electrospun polymeric micro-/nanofibers represent promising carriers for the development of new pharmaceutical formulations with controlled release, as well as increased stability and solubility of EchA, suitable for oral administration, while offering the potential for targeted delivery.

Poly(Sulfobetaine Methacrylate-co-Vinyl Pyrrolidone) Hydrogels as Potential Contact Lenses Delivery Systems for Timolol Maleate

The study reveals the development of novel hydrogels based on sulfobetaine methacrylate (SB) and vinyl pyrrolidone (VP) copolymers as potential contact lenses delivery systems of timolol maleate (TM). The novel copolymer networks demonstrated composition dependent swelling kinetics, where the hydrophilicity of VP and the physical network of SB monomeric units play significant roles. TM loading efficiency appeared to slightly depend on the copolymeric composition, increasing upon VP monomeric unit increase. In contrast, the TM release was prolonged when the SB monomeric units content in the copolymers increased, reaching full drug release for 48 h for the SB-rich networks. The transparency of the hydrogels was also studied and the obtained values demonstrate their applicability as potential materials for soft contact lenses. The study has revealed the potential of these novel copolymeric hydrogels as materials for contact lenses delivery systems of timolol maleate.

Novel insight on chemo-specific detection of toxic environmental chromium residues existing as recalcitrant Cr(III)-carboxyl complexes using plasmonic silver nanoplatform bi-functionalized with citrate and PVP

Chromium (Cr) is a toxic environmental pollutant that majorly exists in trivalent and hexavalent forms. Though Cr(VI) is more dangerous than Cr(III), the trivalent Cr forms complexes with environmentally-available organic molecules. This makes them potentially harmful and difficult to detect. In this study, we have designed an ultrasensitive plasmonic nanosensor using citrate and PVP functionalized Ag nanoparticles (Ag-citrate-PVPNPs) for the detection of trivalent chromium organic complexes such as Cr(III)-EDTA (Cr-E), Cr(III)-acetate (Cr-A), Cr(III)-citrate (Cr-C) and Cr(III)-tartrate (Cr-T). The nanoparticles (NPs) were structurally characterized by XRD, SEM, HRTEM, SAED, EDX and elemental mapping. The citrate and PVP molecules played a vital role in the detection mechanism and stability of the sensor. Upon detection, the yellow-colored Ag-citrate-PVP NPs turned into different shades of brown depending on the type of the Cr complex and concentration. It was accompanied by diminishing and/or shifting UV-Visible absorbance peaks due to the aggregation of Ag-citrate-PVP NPs. Further, a linear relationship was observed between absorbance reduction and analyte concentration. The selectivity tests showed that the sensor was non-functional to other metal ions and inorganic anions. The sensor was optimized using pH and temperature studies. The mechanism of detection was elucidated with the help of characterization techniques such as Raman spectroscopy, FTIR, XPS and UV-visible spectrophotometer. The limit of detection (LOD) was found to be 3.29, 4.87, 1.76 and 1.79 nM for Cr-E, Cr-A, Cr-C and Cr-T complexes respectively. This study provides a rapid and sensitive approach for the detection of multiple Cr(III)-organic complexes present in an aqueous solution.

Fabrications of Electrospun Mesoporous TiO2 Nanofibers with Various Amounts of PVP and Photocatalytic Properties on Methylene Blue (MB) Photodegradation

The superior chemical and electrical properties of TiO₂ are considered to be suitable material for various applications, such as photoelectrodes, photocatalysts, and semiconductor gas sensors; however, it is difficult to commercialize the applications due to their low photoelectric conversion efficiency. Various solutions have been suggested and among them, the increase of active sites through surface modification is one of the most studied methods. A porous nanostructure with a large specific surface area is an attractive solution to increasing active sites, and in the electrospinning process, mesoporous nanofibers can be obtained by controlling the composition of the precursor solution. This study successfully carried out surface modification of TiO₂ nanofibers by mixing polyvinylpyrrolidone with different molecular weights and using diisopropyl azodicarboxylate (DIPA). The morphology and crystallographic properties of the TiO₂ samples were analyzed using a field emission electron microscope and X-ray diffraction method. The specific surface area and pore properties of the nanofiber samples were compared using the Brunauer-Emmett-Teller method. The TiO₂ nanofibers fabricated by the precursor with K-30 polyvinyl pyrrolidone and diisopropyl azodicarboxylate were more porous than the TiO₂ nanofibers without them. The modified nanofibers with K-30 and DIPA had a photocatalytic efficiency of 150% compared to TiO₂ nanofibers. Their X-ray diffraction patterns revealed anatase peaks. The average crystallite size of the modified nanofibers was calculated to be 6.27-9.27 nm, and the specific surface area was 23.5-27.4 m²/g, which was more than 150% larger than the 17.2 m²/g of ordinary TiO₂ nanofibers.

Novel sulfonated poly (vinyl alcohol)/carboxy methyl cellulose/acrylamide-based hybrid polyelectrolyte membranes

Novel polyelectrolytic hybrid membranes are prepared by blending carboxy methyl cellulose (CMC)-polyvinyl alcohol (PVA)-acrylamide (AA). Succinic acid and chlorosulfonic acid (CSA) are employed as crosslinkers and modifiers, respectively. Additionally, carboxylated carbon nanotube (CCNT) and sulfonated activated carbon (SAC) as fillers are used to attain appropriate chemical and mechanical stability for use as polyelectrolyte membranes (PEM). CMC, PVA, and AA are mixed and treated with CSA, CCNT, and SAC in different concentrations. First, CMC/PVA/AA solution is modified using CSA to produce a sulfonated polymeric matrix. Second, a different amount of CCNT or SAC was added as a filler to enhance the ion exchange capacity (IEC), ionic conductivity, and chemical stability. Third, the solution is cast as polyelectrolytic membranes. Chemical interactions between CMC, PVA, AA and other membrane components were confirmed using various characterization techniques such as Raman scattering spectroscopy and Fourier Transform Infrared (FTIR). Furthermore, mechanical strength, methanol uptake, gel fraction, ion exchange capacity (IEC), proton conductivity (PC), chemical and thermal stability were determined as functions of varied membrane modification components. Results reveal that the increase of CSA, CCNT and SAC is leading to increase the IEC values reaching 1.54 mmol/g for (CMC/PVA-4% CSA), 1.74 mmol/g for (CMC/PVA-4%CSA-2%CCNT) and 2.31 mmol/g for (CMC/PVA-4% CSA-2% SAC) comparing to 0.11 mmol/g for non-modified CMC/PVA/AA membrane. Sequentially, the proton conductivity value is changed from 1 × 10^-3 S/cm in non-modified CMC/PVA/AA membrane to 0.082 S/cm for (CMC/PVA-4% CSA), 0.0984 S/cm for (CMC/PVA-4%CSA-2%CCNT) and 0.1050 S/cm for (CMC/PVA-4% CSA-2% SAC). Such results enhance the potential feasibility of modified CMC/PVA/AA hybrid as polyelectrolytic membranes.

Enhancement of Release and Solubility of Curcumin from Electrospun PEO-EC-PVP Tripolymer-Based Nanofibers: A Study on the Effect of Hydrogenated Castor Oil

This study reveals the state-of-the-art fabrication of a tripolymer-based electrospun nanofiber (NF) system to enhance the release, solubility, and transdermal penetration of curcumin (Cur) with the aid of in situ release of infused castor oil (Co). In this regard, Cur-loaded Co-infused polyethylene oxide (PEO), ethyl cellulose (EC), and polyvinyl pyrrolidone (PVP) tripolymer-based NF systems were developed to produce a hybridized transdermal skin patch. Weight percentages of 1-4% Cur and 3-10% of Co were blended with PEO-EC-PEO and PEO-EC-PVP polymer systems. The prepared NFs were characterized by SEM, TEM, FT-IR analysis, PXRD, differential scanning calorimetry (DSC), and XPS. Dialysis membranes and vertical Franz diffusion cells were used to study the in vitro drug release and transdermal penetration, respectively. The results indicated that maintaining a Cur concentration of 1-3 wt % with 3 wt % Co in both PEO-EC-Co-Cur@PEO and PEO-EC-Co-Cur@PVP gave rise to nanofibers with lowered diameters (144.83 ± 48.05-209.26 ± 41.80 nm and 190.20 ± 59.42-404.59 ± 45.31 nm). Lowered crystallinity observed from the PXRD patterns and the disappearance of exothermic peaks corresponding to the melting point of Cur suggested the formation of an amorphous NF structure. Furthermore, the XPS data revealed that the Cur loading will possibly take place at the inner interface of PEO-EC-Co-PEO and PEO-EC-Co-PVP NFs rather than on the surface. The beneficiary role of Co on the release and dermal penetration of Cur was further confirmed from the respective release data which indicated that PEO-EC-Co-Cur@PEO would lead to a rapid release (4-5 h), while PEO-EC-Co-Cur@PVP would lead to a sustained release over a period of 24 h in the presence of Co. Transdermal penetration of the released Cur was further evidenced with the development of color in the receiver compartment of the diffusion cell. DPPH results further corroborated that a sustained antioxidant activity is observed in the released Cur where the free-radical scavenging activity is intact even after subjecting to an electrospinning process and under extreme freeze-thaw conditions.

Co-delivery of gentiopicroside and thymoquinone using electrospun m-PEG/PVP nanofibers: In-vitro and In vivo studies for antibacterial wound dressing in diabetic rats

Nanofibers (NFs) provide several delivery advantages like their great flexibility and similarity with extracellular matrix (ECM) which qualify them to be the unique model of a wound dressing. NFs could create mats of polymeric matrix loaded with an active agent enhancing its solubility and stability. In our study, Gentiopicroside (GPS) and Thymoquinone (TQ) loaded in NFs polymeric mats composed of coblended polyvinyl pyrrolidine (PVP) and methyl ether Polyethylene glycol (m-PEG) were fabricated via electrospinning technique. A morphological study using Scanning Electron Microscopy (SEM) was performed for all formulae as well as in vitro release study using High-performance Liquid chromatography (HPLC) for sample analysis. The optimized formula (F3) was chosen for further assays using Fourier-Transform Infrared Spectroscopy (FTIR), and Differential Scanning Calorimetry (DSC). Study of the antibacterial effect, and in vivo healing action for diabetic infected wounds to quantify Tumor necrosis factor-alpha and Cyclooxygenase-2 were also investigated. F3 achieved the highest % cumulative release (99.79 ± 6.47 for GPS and 96.89 ± 6.87 for TQ) at 60 min, and a smaller diameter (200 nm) showing significant anti-bacterial effects with well-organized skin architecture demonstrating great healing signs. Our results revealed that m-PEG/PVP NFs mats loaded with GPS and TQ could be considered an optimal wound care dressing.

Preparation, Characterization, and Desalination Study of Polystyrene Membrane Integrated with Zeolite Using the Electrospinning Method

The novel composite membranes of Styrofoam (polystyrene) integrated with natural zeolite particles were produced using the electrospinning method for desalination purposes. The product was then characterized using FTIR, XRD, and TGA. Subsequently, the effect of different zeolite concentrations, namely 0, 5, 10, 15, 20, and 30 wt.% on its morphological structure and effectiveness was determined. Desalination of artificial seawater was carried out using the gravitational filtration principle to confirm the membrane's capabilities, after which its performance was evaluated using 4 wt.% NaCl solution. The morphological analysis showed that the composite membrane obtained has a smooth surface with microdomains on a few parts, which indicates the presence of zeolite. The result showed that the product integrated with 30 wt.% zeolites had the best performance in the desalination of artificial seawater. This was determined by comparing the conductivity value of the seawater before and after the process. The conductivity led to an 82.63% decrease using 30 wt.% zeolites. The developed polystyrene membrane embedded with zeolite has good thermal stability, hence, it can be used for desalination.

Novel fabricated low-cost hybrid polyacrylonitrile/polyvinylpyrrolidone coated polyurethane foam (PAN/PVP@PUF) membrane for the decolorization of cationic and anionic dyes

Dyes are recalcitrait organic pollutants threatening the aquatic environment and human health. In the present study, a novel low-cost hybrid membrane was fabricated by coating polyurethane foam (PUF) with polyacrylonitrile/polyvinylpyrrolidone (PAN/PVP) via phase inversion technique from casting solutions consisting of PAN and PVP with Dimethyl formamide (DMF) and applied for removal of cationic (Methylene Blue (MB)) and anionic (Methyl Orange (MO)) dyes from aqueous solutions. The as-prepared membrane was first characterized by Scan Electron Microscope (SEM), Fourier Transform Infrared (FTIR), Energy Dispersive Spectrometry (EDS), etc. Then, batch experiments were conducted to optimize the adsorption conditions, including contact time, adsorbent dose, dyes concentration, and pH. The dye removal results fitted with pseudo first and second-order kinetics; Langmuir, Freundlich, and Temkin isotherms' models. The maximum dye decolorization was approximately 97% and 95% within 60 and 120 min using 0.5 and 1 g of the fabricated composite for MB and MO, respectively. The kinetic studies showed rapid sorption dynamics following a second-order kinetic model. In addition, dye adsorption equilibrium data fitted well to the Freundlich isotherm with monolayer maximum adsorption capacity of 6.356 and 3.321 mg/g for MO and MB dye, respectively. Thus, the novel hybrid membrane is promising as a cheap and efficient adsorbent for the removal of both cationic and anionic dyes from wastewater. The current study demonstrated a new avenue to achieve efficient management of dyes in aquatic environments.

Preparation and characterization of wet adhesives based on (poly (vinyl butyral-co-vinyl alcohol-co-vinyl acetate)/castor oil/styrene butadiene rubber) using gamma irradiation for trapping of reptiles and rodents

Wet adhesives from poly (vinyl butyral-co-vinyl alcohol-co-vinyl acetate), castor oil, and styrene butadiene rubber were prepared at variable compositions. These components were exposed to a certain range of irradiation dose for γ-rays. Wet adhesives were characterized by adhesion force, Fourier transform infrared, thermogravimetric analysis and derivative thermal gravimetric, gel permeation chromatography, proton nuclear magnetic resonance spectroscopy and scan electron microscopy. Results declared that dose and composition have significant effect on features of wet adhesives. Further, the adhesion force and thermal stability of wet adhesives improved by increasing the irradiation dose. Moreover, the adhesion force reached ~ 690 (kPa). The analysis of gel permeation chromatography showed that molecular weight of wet adhesive 48,921 (g/mol). The wet adhesives were exploited to trap reptiles and rodents. Through the results, it can be observed that the wet adhesives had good efficiency for trapping the reptiles and rodents. The results showed that the best sample of wet adhesive was from 98% of [poly (vinyl butyral-co-vinyl alcohol-co-vinyl (10%)/castor oil (90%))] to [2% of styrene butadiene rubber] at 30 kGy In conclusion, this study referred that this type of wet adhesive has an excellent ability to adhere and trap of reptiles and rodents such as geckos and mice respectively. Consequently, these wet adhesives could be utilized in pilot scale.

Evaluation of bactericidal potential and catalytic dye degradation of multiple morphology based chitosan/polyvinylpyrrolidone-doped bismuth oxide nanostructures

In this study, 0.02 and 0.04 wt% of chitosan (CS) were successfully incorporated in a fixed amount of polyvinylpyrrolidone (PVP)-doped Bi₂O₃ nanostructures (NSs) via a co-precipitation approach. The purpose of this research was to degrade hazardous methylene blue dye and assess antimicrobial potential of the prepared CS/PVP-doped Bi₂O₃ nanostructures. In addition, optical characteristics, charge recombination rate, elemental composition, phase formation, surface morphology, functional groups, d-spacing, and crystallinity of the obtained nanostructures were investigated. CS/PVP-doped Bi₂O₃ nanostructures exhibited efficient catalytic activity (measured as 99%) in a neutral medium for dopant-free nanostructures while the inhibition zone was measured using a Vernier caliper against pathogens Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) at low and high doses to check antimicrobial activity. Strong bactericidal action was recorded against S. aureus bacteria such that a significant inhibition zone was measured at 3.09 mm.

Antimicrobial Biomaterial on Sutures, Bandages and Face Masks with Potential for Infection Control

Antimicrobial resistance (AMR) is a challenge for the survival of the human race. The steady rise of resistant microorganisms against the common antimicrobials results in increased morbidity and mortality rates. Iodine and a plethora of plant secondary metabolites inhibit microbial proliferation. Antiseptic iodophors and many phytochemicals are unaffected by AMR. Surgical site and wound infections can be prevented or treated by utilizing such compounds on sutures and bandages. Coating surgical face masks with these antimicrobials can reduce microbial infections and attenuate their burden on the environment by re-use. The facile combination of Aloe Vera Barbadensis Miller (AV), Trans-cinnamic acid (TCA) and Iodine (I₂) encapsulated in a polyvinylpyrrolidone (PVP) matrix seems a promising alternative to common antimicrobials. The AV-PVP-TCA-I₂ formulation was impregnated into sterile discs, medical gauze bandages, surgical sutures and face masks. Morphology, purity and composition were confirmed by several analytical methods. Antimicrobial activity of AV-PVP-TCA-I₂ was investigated by disc diffusion methods against ten microbial strains in comparison to gentamycin and nystatin. AV-PVP-TCA-I₂ showed excellent antifungal and strong to intermediate antibacterial activities against most of the selected pathogens, especially in bandages and face masks. The title compound has potential use for prevention or treatment of surgical site and wound infections. Coating disposable face masks with AV-PVP-TCA-I₂ may be a sustainable solution for their re-use and waste management.

Preparation and characterization of Pullulan-based nanocomposite scaffold incorporating Ag-Silica Janus particles for bone tissue engineering

A nanocomposite bone scaffold was fabricated from pullulan, a natural extracellular polysaccharide. Pullulan (PULL) was blended with polyvinylpyrrolidone (PVP), and a nano-platform with ball-stick morphology, Ag-Silica Janus particles (Ag-Silica JPs), which were utilized to fabricate nanocomposite scaffold with enhanced mechanical and biological properties. The Ag-Silica JPs were synthesized via a one-step sol-gel method and used to obtain synergistic properties of silver and silica's antibacterial and bioactive effects, respectively. The synthesized Ag-Silica JPs were characterized by means of FE-SEM, DLS, and EDS. The PULL/PVP scaffolds containing Ag-Silica JPs, fabricated by the freeze-drying method, were evaluated by SEM, EDS, FTIR, XRD, ICP and biological analysis, including antibacterial activity, bioactivity, cell viability and cell culture tests. It was noted that increasing Ag-Silica JPs amounts to an optimum level (1% w/w) led to an improvement in compressive modulus and strength of nanocomposite scaffold, reaching 1.03 ± 0.48 MPa and 3.27 ± 0.18, respectively. Scaffolds incorporating Ag-Silica JPs also showed favorable antibacterial activity. The investigations through apatite forming ability of scaffolds in SBF indicated spherical apatite precipitates. Furthermore, the cell viability test proved the outstanding biocompatibility of nanocomposite scaffolds (more than 90%) confirmed by cell culture tests showing that increment of Ag-Silica JPs amounts led to better adhesion, proliferation, ALP activity and mineralization of MG-63 cells.

Preparation and characterization of innovative electrospun nanofibers loaded with pharmaceutically applicable ionic liquids

Keeping up with cutting edge research in the field of drug delivery, the overall goal of this study was to develop innovative electrospun nanofibers loaded with ionic liquids (ILs) as active pharmaceutical ingredients (APIs). For the first time, a novel approach was examined by combining biocompatible polymer, poly (ethylene oxide) (PEO), and pharmaceutical ILs in an electrospinning process to develop nanofibers with high drug loading (up to 47%). Firstly, two well-known local anaesthetic drugs, lidocaine and procaine, were modified into ILs with the salicylate, forming lidocaine salicylate and procaine salicylate. Its dual-functional nature and increased water solubility for 4- to 10-fold depending on the drug used contribute to overcoming current hurdles encountered by APIs such as poor solubility, low bioavailability, and polymorphism of the solid-state. Nanofibers were formulated using solutions tested for density, viscosity, electrical conductivity, and small-angle X-ray scattering by varying PEO molecular weight and the PEO to IL mass ratio. Scanning electron microscopy showed the surface morphology of the obtained nanofibers, while Fourier transform infrared spectroscopy and differential scanning calorimetry confirmed IL in the nanofibers in an amorphous state. Thus, nanofibers with incorporated IL represent well-known drugs in the new form and a novel dermal application delivery system.

Electrospun 5-Chloro-7-iodo-8-hydroxyquinoline (Clioquinol)-Containing Poly(3-hydroxybutyrate)/Polyvinylpyrrolidone Antifungal Materials Prospective as Active Dressings against Esca

Esca is a grapevine disease known for centuries which pertains to the group of so-called vine trunk diseases. Phaeomoniella chlamydospora (P. chlamydospora) and Phaeoacremonium aleophilum (P. aleophilum) are the two main fungal pathogens associated with esca. Novel fibrous materials with antifungal properties based on poly(3-hydroxybutyrate) (PHB), polyvinylpyrrolidone (PVP) and 5-chloro-7-iodo-8-hydroxyquinoline (clioquinol, CQ) were developed. One-pot electrospinning (“in” strategy) or electrospinning in conjunction with electrospraying (“on” strategy) were applied to obtain the materials. The materials’ morphology and their surface chemical composition were examined using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). CQ incorporated in the bulk of the fibers or in PVP particles deposited on the fibers was in the amorphous phase, which was confirmed by differential scanning calorimetry (DSC) and X-ray diffraction analysis (XRD). The in vitro release of CQ depended on the composition of the electrospun materials and on their design. The performed microbiological screening revealed that, unlike the non-loaded mats, the fibrous mats loaded with CQ were effective in inhibiting the growth of the pathogenic P. chlamydospora and P. aleophilum fungi. Therefore, the created materials are promising as active dressings for grapevine protection against esca.

Impact of Polymer Type on Thermal Degradation of Amorphous Solid Dispersions Containing Ritonavir

High-temperature exposure during hot melt extrusion processing of amorphous solid dispersions may result in thermal degradation of the drug. Polymer type may influence the extent of degradation, although the underlying mechanisms are poorly understood. In this study, the model compound, ritonavir (T_m = 126 °C), undergoes thermal degradation upon high-temperature exposure. The extent of degradation of ritonavir in amorphous solid dispersions (ASDs) formulated with poly(vinylpyrrolidone) (PVP), poly(vinylpyrrolidone) vinyl acetate copolymer (PVP/VA), hydroxypropyl methylcellulose acetate succinate (HPMCAS), and hydroxypropyl methylcellulose (HPMC) following isothermal heating and hot melt extrusion was evaluated, and mechanisms related to molecular mobility and intermolecular interactions were assessed. Liquid chromatography-mass spectrometry (LC-MS/MS) studies were used to determine the degradation products and pathways and ultimately the drug-polymer compatibility. The dominant degradation product of ritonavir was the result of a dehydration reaction, which then catalyzed a series of hydrolysis reactions to generate additional degradation products, some newly reported. This reaction series led to accelerated degradation rates with protic polymers, HPMCAS and HPMC, while ASDs with aprotic polymers, PVP and PVP/VA, had reduced degradation rates. This work has implications for understanding mechanisms of thermal degradation and drug-polymer compatibility with respect to the thermal stability of amorphous solid dispersions.

Topical Delivery of Niacinamide to Skin Using Hybrid Nanogels Enhances Photoprotection Effect

Niacinamide (NIA) has been widely used in halting the features of ageing by acting as an antioxidant and preventing dehydration. NIA’s physicochemical properties suggest difficulties in surpassing the barrier imposed by the stratum corneum layer to reach the target in the skin. To improve cutaneous delivery of NIA, a hybrid nanogel was designed using carrageenan and polyvinylpyrrolidone polymers combined with jojoba oil as a permeation enhancer. Three different types of transethosomes were prepared by the thin-film hydration method, made distinct by the presence of either an edge activator or a permeation enhancer, to allow for a controlled delivery of NIA. Formulations were characterized by measurements of size, polydispersity index, zeta potential, encapsulation efficiency, and loading capacity, and by evaluating their chemical interactions and morphology. Skin permeation assays were performed using Franz diffusion cells. The hybrid hydrogels exhibited robust, porous, and highly aligned macrostructures, and when present, jojoba oil changed their morphology. Skin permeation studies with transethosomes-loaded hydrogels showed that nanogels per se exhibit a more controlled and enhanced permeation, in particular when jojoba oil was present in the transethosomes. These promising nanogels protected the human keratinocytes from UV radiation, and thus can be added to sunscreens or after-sun lotions to improve skin protection.

Development and evaluation of pH-sensitive biodegradable ternary blended hydrogel films (chitosan/guar gum/PVP) for drug delivery application

pH responsive hydrogels have gained much attraction in biomedical fields. We have formulated ternary hydrogel films as a new carrier of drug. Polyelectrolyte complex of chitosan/guar gum/polyvinyl pyrrolidone cross-linked via sodium tripolyphosphate was developed by solution casting method. Fourier transform infrared spectroscopy, scanning electron microscopy and thermogravimetric analysis were conducted to examine the interactions between the polymeric chains, surface morphology and thermal stability, respectively. The swelling tests resulted that the swelling was reduced with the increase in the concentration of crosslinker due to the more entangled arrangement and less availability of pores in hydrogels. Ciprofloxacin hydrochloride was used as a model drug and its release in simulated gastric fluid, simulated intestinal fluid and phosphate buffer saline solution was studied. pH responsive behaviour of the hydrogels have subjected these hydrogels for drug release applications.

Impact of the solvent composition on the structural and mechanical properties of customizable electrospun poly(vinylpyrrolidone) fiber mats

The performance of fibrous membrane composites fabricated via electrospinning is strongly influenced by the solution's properties, process variables and ambient conditions, although a precise mechanism for controlling the properties of the resulting composite has remained elusive. In this work, we focus on the fabrication of electrospun poly(vinylpyrrolidone) (PVP) fibers, by varying both the polymer concentration and the mixture of ethanol (EtOH) and dimethylformamide (DMF) used as solvent. The impact of the solvent composition on the structural properties is assessed by a combined experimental and theoretical approach, employing scanning electron microscopy (SEM), differential scanning calorimetry (DSC), rheology, Fourier-transform infrared spectroscopy (FTIR) and stress-strain curves obtained from tensile tests to characterize the fibrous membranes produced, and density functional theory (DFT) calculations to explain the solvent's affect on PVP crystallization. We establish a morphological phase diagram, and propose a possible mechanism based on the measured fiber diameter distribution, the viscoelastic properties of the precursor solution, the correlation between the functional groups and the mechanical properties, the thermal transitions and the degree of crystallinity. We also employ DFT calculations to model the polymer coverage at equilibrium of a PVP polymer chain in the presence of EtOH/DMF solvent mixtures to corroborate the crucial role their O or -OH groups play in achieving high PVP coverages and promoting the stability of the resulting fiber. These findings will be valuable to researchers interested in predicting, modulating, and controlling both a fiber's morphology and its concomitant physico-chemical properties.

Design and development of electrospun SPEEK incorporated with aminated zirconia and curcumin nanofibers for periodontal regeneration

Periodontal disease disturbs the supportive tissues around the teeth such as connective tissue, gingival tissue, periodontal ligaments and alveolar bone. Previously, treatment of periodontitis was embattled by repopulating the affected site with cells that has capacity to regenerate damaged tissue by endorsing the perception of guided tissue regeneration but it entails additional surgery owing to non-biodegradability. Biodegradable polymeric nanofibrous scaffold imitating extracellular matrix (ECM) delivering functionalized nanoparticles loaded with therapeutic drug have the ability to support cellular functions thereby enhancing regeneration. Present study explores novel amine functionalized zirconia nanoparticle loaded curcumin incorporated SPEEK nanofibrous scaffolds to address periodontal regeneration. Zirconia - crown of dental therapeutics, its amine functionalization further enhanced the strength and cyto-compatibility. Carbon-Silica NMR (59.9 and 69.8 ppm), FT-IR (3426 cm^-1), EDAX and XRD (28.9°_, 31.6° and 38.2° pertaining to [-1 1 1], [1 1 1] and [1 2 0] planes) analysis confirmed the effective functionalization of the zirconia nanoparticle with the amine group. Electrospinning was carried out at a voltage of 20 kV and flow rate of 0.05 ml/h. Fabricated nanofibers were highly dense, porous with interconnected fibrous structures that bio-mimic ECM. They exhibited an average diameter of 187 ± 2 nm (SPEEK), 192 ± 2 nm (SPEEK + NH₂-ZrO₂), and 256 ± 17 nm (SPEEK + NH₂-ZrO₂+Cur). Extensively discovered anti-bacterial traits of curcumin supplemented the advantage for the treatment of periodontitis. Incorporated materials improve the physico-chemical, mechanical and biological characteristics of nanofibers. FT-IR, EDAX and XRD analysis of the fabricated nanofibrous scaffold demonstrated the effective incorporation of aminated zirconia loaded curcumin. Results of cyto-compatibility analysis of SPEEK + NH₂-ZrO₂+Cur nanofibrous scaffold depicted a cell viability of 100 ± 1.62%. Results of anti-bacterial assay with zone of inhibition was 6.5 ± 0.5 mm (SPEEK), 7.5 ± 1 mm (SPEEK + NH₂-ZrO₂), and 8 ± 1 mm (SPEEK + NH₂-ZrO₂+Cur). Thus, the fabricated bio-material is cyto-compatible, non-toxic and effective against pathogens exploiting higher potential for periodontal regeneration applications.

Self-Assembled Hierarchical Cu x O@C18H36O2 Nanoflakes for Superior Fenton-like Catalysis over a Wide Range of pH

A novel copper-based catalyst supported by a long-chain hydrocarbon stearic acid (Cu _x O@C₁₈H₃₆O₂) was synthesized by a hydrothermal method and double replacement reactions. The as-prepared catalyst is shown as self-assembled hierarchical nanoflakes with an average size of ∼22 nm and a specific surface area of 51.4 m² g^-1. The catalyst has a good performance on adsorption as well as Fenton-like catalytic degradation of Rhodamine B (RhB). The catalyst (10 mg/L) showed an excellent adsorption efficiency toward RhB (20 mg/L) for pH ranging from 5 to 13, with the highest adsorption rate (99%) exhibited at pH 13. The Fenton-like catalytic degradation reaction of RhB (20 mg/L) by Cu _x O@C₁₈H₃₆O₂ nanoflakes was effective over a wide range of pH of 3-11, and ^•OH radicals were generated via Cu₂O/H₂O₂ interactions in acidic conditions and CuO/H₂O₂ reactions in a neutral solution. The highest efficiency catalytic degradation of RhB (20 mg/L) was 99.2% under acidic conditions (pH = 3, H₂O₂ = 0.05 M), with an excellent reusability of 96% at the 6th cycle. The results demonstrated that the as-prepared Cu _x O@C₁₈H₃₆O₂ nanoflakes are an efficient candidate for wastewater treatment, with excellent adsorption capacity and superior Fenton-like catalytic efficiency and stability for RhB.

Development of Nervilia fordii Extract-Loaded Electrospun PVA/PVP Nanocomposite for Antioxidant Packaging

An ethyl acetate extract from of Nervilia fordii (NFE) with considerable suppression activity on lipid peroxidation (LPO) was first obtained with total phenolic and flavonoid contents and anti-LPO activity (IC₅₀) of 86.67 ± 2.5 mg GAE/g sample, 334.56 ± 4.7 mg RE/g extract and 0.307 mg/mL, respectively. In order to improve its stability and expand its application in antioxidant packaging, the nano-encapsulation of NFE within poly(vinyl alcohol) (PVA) and polyvinyl(pyrrolidone) (PVP) bio-composite film was then successfully developed using electrospinning. SEM analysis revealed that the NFE-loaded fibers exhibited similar morphology to the neat PVA/PVP fibers with a bead-free and smooth morphology. The encapsulation efficiency of NFE was higher than 90% and the encapsulated NFE still retained its antioxidant capacity. Fourier transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD) analysis confirmed the successful encapsulation of NFE into fibers and their compatibility, and the thermal stability of which was also improved due to the intermolecular interaction demonstrated by thermo gravimetric analysis (TGA). The ability to preserve the fish oil’s oxidation and extend its shelf-life was also demonstrated, suggesting the obtained PVA/PVP/NFE fiber mat has the potential as a promising antioxidant food packaging material.

Isoflavonoid-Antibiotic Thin Films Fabricated by MAPLE with Improved Resistance to Microbial Colonization

Staphylococcus aureus (Gram-positive) and Pseudomonas aeruginosa (Gram-negative) bacteria represent major infectious threats in the hospital environment due to their wide distribution, opportunistic behavior, and increasing antibiotic resistance. This study reports on the deposition of polyvinylpyrrolidone/antibiotic/isoflavonoid thin films by the matrix-assisted pulsed laser evaporation (MAPLE) method as anti-adhesion barrier coatings, on biomedical surfaces for improved resistance to microbial colonization. The thin films were characterized by Fourier transform infrared spectroscopy, infrared microscopy, and scanning electron microscopy. In vitro biological assay tests were performed to evaluate the influence of the thin films on the development of biofilms formed by Gram-positive and Gram-negative bacterial strains. In vitro biocompatibility tests were assessed on human endothelial cells examined for up to five days of incubation, via qualitative and quantitative methods. The results of this study revealed that the laser-fabricated coatings are biocompatible and resistant to microbial colonization and biofilm formation, making them successful candidates for biomedical devices and contact surfaces that would otherwise be amenable to contact transmission.

Facile Synthesis of Bio-Antimicrobials with "Smart" Triiodides

Multi-drug resistant pathogens are a rising danger for the future of mankind. Iodine (I₂) is a centuries-old microbicide, but leads to skin discoloration, irritation, and uncontrolled iodine release. Plants rich in phytochemicals have a long history in basic health care. Aloe Vera Barbadensis Miller (AV) and Salvia officinalis L. (Sage) are effectively utilized against different ailments. Previously, we investigated the antimicrobial activities of smart triiodides and iodinated AV hybrids. In this work, we combined iodine with Sage extracts and pure AV gel with polyvinylpyrrolidone (PVP) as an encapsulating and stabilizing agent. Fourier transform infrared spectroscopy (FT-IR), Ultraviolet-visible spectroscopy (UV-Vis), Surface-Enhanced Raman Spectroscopy (SERS), microstructural analysis by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-Ray-Diffraction (XRD) analysis verified the composition of AV-PVP-Sage-I₂. Antimicrobial properties were investigated by disc diffusion method against 10 reference microbial strains in comparison to gentamicin and nystatin. We impregnated surgical sutures with our biohybrid and tested their inhibitory effects. AV-PVP-Sage-I₂ showed excellent to intermediate antimicrobial activity in discs and sutures. The iodine within the polymeric biomaterial AV-PVP-Sage-I₂ and the synergistic action of the two plant extracts enhanced the microbial inhibition. Our compound has potential for use as an antifungal agent, disinfectant and coating material on sutures to prevent surgical site infections.

Rationally design of electrospun polysaccharides polymeric nanofiber webs by various tools for biomedical applications: A review

Nanofibers have a particular benefit when delivering a spectrum of therapeutic drugs for diverse biomedical applications. Nanofibers are easily fabricated from cellulose acetate, chitosan, polycaprolactone, and other polymers with regulated morphology and release profiles due to nanotechnology's recent advancement. This review will provide the latest approaches to the fabrication of electrospun nanofibers containing herbal extracts, antimicrobial peptides, and antibiotics for wound-healing potential. Besides, synthesis and evaluation of nanofibrous mats, including conducting polymer and evaluate their possibility for wound healing. In addition, nanofibers are loaded with some drugs for skin cancer treatment and contain growth factors for tissue regeneration. Also, the current two-dimensional nanofibers limitations and the various techniques for convert two-dimensional to three-dimension nanofibers to avoid these drawbacks. Moreover, the future direction in improving the three-dimensional structure and functionality has been including.