Search Results (1,400)

Zero-valent copper and silver metals (Ms) nanoparticles (NPs) supported on carboxymethylcellulose (CMC) were synthesized for treating Enterotoxigenic Escherichia coli fimbriae 4 (ETEC:F4), a major cause of diarrhea in post-weaned pigs. The antibacterial properties of Cu⁰/CMC and Ag⁰/CMC were assessed on infected porcine intestinal enterocyte IPEC-J2, an in vitro model mimicking the small intestine. The lower average particle size (218 nm) and polydispersity index [PDI]: 0.25) for Ag⁰/CMC, when compared with those of Cu⁰/CMC (367 nm and PDI 0.96), were explained by stronger Ag⁰/CMC interactions. The minimal inhibitory concentration (MIC) and half inhibitory concentration (IC₅₀) of Ag⁰/CMC were lower in both bacteria and IPEC-J2 cells than those of Cu⁰/CMC, confirming that silver nanoparticles are more bactericidal than copper counterparts. IPEC-J2, less sensitive in MNP/CMC treatment, was used to further investigate the infective process by ETEC:F4. The IC₅₀ of MNP/CMC increased significantly when infected IPEC-J2 cells and ETEC were co-treated, showing an inhibition of the cytotoxicity effect of ETEC:F4 infection and protection of treated IPEC-J2. Thus, it appears that metal insertion in CMC induces an inhibiting effect on ETEC:F4 growth and that MNP/CMC dispersion governs the enhancement of this effect. These results open promising prospects for metal-loaded biopolymers for preventing and treating swine diarrhea. Full article

Background: During the dissolution of amorphous solid dispersion (ASD) formulations, the drug load (DL) often impacts the release mechanism and the occurrence of loss of release (LoR). The ASD/water interfacial gel layer and its specific phase behavior in connection with DL strongly dictate the release mechanism and LoR of ASDs, as reported in the literature. Thermodynamically driven liquid-liquid phase separation (LLPS) and/or drug crystallization at the interface are the key phase transformations that drive LoR. Methods: In this study, a combination of Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) thermodynamic modeling and in silico molecular simulation was applied to investigate the release mechanism and the occurrence LoR of an ASD formulation consisting of ritonavir as the active pharmaceutical ingredient (API) and the polymer, polyvinylpyrrolidone-co-vinyl acetate (PVPVA64). A thermodynamically modeled ternary phase diagram of ritonavir (PVPVA64) and water was applied to predict DL-dependent LLPS in the ASD/water interfacial gel layer. Microscopic Erosion Time Testing (METT) was used to experimentally validate the phase diagram predictions. Additionally, in silico molecular simulation was applied to provide further insights into the phase separation, the release mechanism, and aggregation behavior on a molecular level. Results: Thermodynamic modeling, molecular simulation, and experimental results were consistent and complementary, providing evidence that ASD/water interactions and phase separation are essential factors driving the dissolution behavior and LoR at 40 wt% DL of the investigated ritonavir/PVPVA64 ASD system, consistent with previous studies. Conclusions: This study provides insights into the potential of blending thermodynamic modeling, molecular simulation, and experimental research to comprehensively understand ASD formulations. Such a combined approach can be leveraged as a computational framework to gain insights into the ASD dissolution mechanism, thereby facilitating in silico screening, designing, and optimization of formulations with the benefit of significantly reducing the number of experimental tests. Full article

For the first time, density functional theory (DFT) calculations have been employed for the measurement of the structural, mechanical, optical, and electrical properties of a bismuth-layered structure ferroelectrics (BLSFs) family member possessing an orthorhombic structure with Cmc2₁ space group. Based on the exchange–correlation approximation, our calculations show that Pb₂Bi₄Ti₅O₁₈ possesses an indirect band gap, while the materials X₂Bi₄Ti₅O₁₈ (X = Ba, Ca, and Sr) demonstrate direct band gap, where the estimated density functional fundamental band gap values lie between 1.84 to 2.33 eV, which are ideal for photovoltaic applications. The optical performance of these materials has been investigated by tuning the band gaps. The materials demonstrated outstanding optical characteristics, such as high absorption coefficients and low reflection. They exhibited impressive absorption coefficient (α = 10⁵ cm⁻¹) throughout a broad energy range, especially in the visible spectrum (10⁵ cm⁻¹ region). The findings show that the compounds demonstrate lower reflectivity in the visible and UV regions, making them suitable for single-junction photovoltaic cells and optoelectronic applications. The Voigt–Reuss–Hill averaging technique has been employed to derive elastic parameters like bulk modulus (B), Young’s modulus, shear modulus (G), the Pugh ratio (B/G) and the Frantesvich ratio (G/B) at 0.1 GPa. The mechanical stability of the compounds was analyzed using the Born stability criteria. Pugh’s ratio and Frantesvich’s ratio show that all the compounds are ductile, making them ideal for flexible optical applications. Full article

Active, fully biobased film-forming dispersions (FFDs) with highly promising results for sliced soft bread preservation were successfully elaborated from carboxymethyl cellulose (CMC) and chitosan (CH) using a simple method based on pH adjustments. They consisted of the association of polysaccharides and oleic acid (OL) added with cinnamon (CEO) or ginger (GEO) essential oils. The chemical compositions of the commercial essential oils were first determined via GC/MS, with less than 3% of compounds unidentified. The films obtained from FFDs were characterized by SEM, FTIR and DSC, indicating specific microstructures and some interactions between essential oils and the polymer matrix. CEO-based films exhibited higher antioxidant properties and a lower minimal inhibitory concentration in terms of antifungal properties. From experiments on sliced soft bread, the ginger-based films could increase the shelf life up to 20 days longer than that of the control. Even more promising, cinnamon-based films led to complete fungal inhibition in bread slices that was maintained beyond 60 days. Enumeration of the yeasts and molds for the FFD-coated breads revealed complete inhibition even after 15 days of storage with the FFDs containing the highest concentration of CEO. Full article

A maternal diet rich in dietary fiber, such as β-glucan, plays a crucial role in the offspring’s acquisition of gut microbiota and the subsequent shaping of its microbiome profile and metabolome. This in turn has been shown to aid in neurodevelopmental processes, including early microglial maturation and immunomodulation via metabolites like short chain fatty acids (SCFAs). This study aimed to investigate the effects of oat β-glucan supplementation, solubilized by citric acid hydrolysis, from gestation to adulthood. Female C57BL/6J mice were orally supplemented with soluble oat β-glucan (ObG) or carboxymethyl cellulose (CMC) via drinking water at 200 mg/kg body weight during breeding while the control group received 50 mg/kg body weight of carboxymethyl cellulose. ObG supplementation increased butyrate production in the guts of both dams and 4-week-old pups, attributing to alterations in the gut microbiota profile. One-week-old pups from the ObG group showed increased neurodevelopmental markers similar to four-week-old pups that also exhibited alterations in serum markers of metabolism and anti-inflammatory cytokines. Notably, at 8 weeks, ObG-supplemented pups exhibited the highest levels of spatial memory and cognition compared to the control and CMC groups. These findings suggest a potential enhancement of neonatal neurodevelopment via shaping of early-life gut microbiome profile, and the subsequent increased later-life cognitive function. Full article

The nasal route of administration can bypass the blood–brain barrier in order to obtain a higher concentration in the brain, thus offering a feasible alternative route of administration for diseases associated with the central nervous system. The advantages of the intranasal administration and the potential favorable therapeutic effects of intranasally administered insulin led to the formulation of carboxymethyl chitosan (CMC) and sodium hyaluronate (NaHA) hydrocolloidal systems with insulin for nasal administration, targeting nose-to-brain delivery and the initial assessment of these systems. The influence of the formulation variables on the response parameters defined as surface properties, rheology, and in vitro release of insulin were analyzed using experimental design and statistical programs (Modde and Minitab software). The systems recorded good wetting and adhesion capacity, allowing the spread of the hydrocolloidal systems on the nasal mucosa. The samples had a pseudoplastic flow and the rapid release of the insulin was according to our objective. According to the physico-chemical characterization and preliminary assessment, these formulations are appropriate for administration on the nasal mucosa, but further studies are necessary to demonstrate the beneficial therapeutic actions and the safety of using intranasal insulin. Full article

Nanocomposites (NCs) consisting of zero-valent iron nanoparticles (nZVI) immobilized in chitosan (CS) were prepared and employed for the removal of hexavalent chromium (Cr(VI)) from both synthetic and real wastewater. Medium (MCS)- and high (HCS)-molecular-weight chitosan and stabilization with carboxymethylcellulose (CMC) and different nZVI loads were explored. Characterization through scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDS) and X-ray diffraction (XRD) revealed millimeter-sized spheres with micrometer-sized nZVI clusters randomly distributed. Better nanoparticle dispersion was observed in NCs from the CMC-MCS and HCS combinations. Fourier-transform infrared spectroscopy (FTIR) analysis indicated that CS binds to Fe(II) or Fe(III) on the surface of nZVI through its functional groups -CONH-, -N-H, and -C-OH and through the -COO− functional group of CMC, forming a bidentate bridge complex. Through experiments with synthetic waters, it was found that the elimination of Cr(VI) was favored by lowering the pH, obtaining the maximum percentage of Cr(VI) removal at pH 5.5. With real waters, it was shown that increasing the mass of NCs also improved the removal of Cr(VI), following a pseudo-second-order adsorption kinetics. The synthesized materials show great potential for applications in environmental remediation, showing good efficiency in the removal of Cr(VI) in wastewater. Full article

Nano- and micro-sized vesicular and colloidal structures mediate cell–cell communication. They are important players in the physiology of plants, animals, and humans, and are a subject of increasing interest. We investigated the effect of three surfactants, N-cetylpyridinium chloride (CPC), sodium dodecyl sulfate (SDS), and Triton X-100 (TX100), and two anionic polyelectrolytes, sodium polystyrene sulfonate (NaPSS) and sodium polymethacrylate (NaPMA), on nanoliposomes. In addition, the effect of SDS and TX100 on selected biological membranes (erythrocytes and microalgae) was investigated. The liposomes were produced by extrusion and evaluated by microcalorimetry and light scattering, based on the total intensity of the scattered light (I_tot), hydrodynamic radius (R_h), radius of gyration (R_g), shape parameter p (=R_h/R_g,0), and polydispersity index. The EPs shed from erythrocytes and microalgae Dunaliella tertiolecta and Phaeodactylum tricornutum were visualized by scanning electron microscopy (SEM) and analyzed by flow cytometry (FCM). The R_h and I_tot values in POPC liposome suspensions with added CPC, SDS, and TX100 were roughly constant up to the respective critical micelle concentrations (CMCs) of the surfactants. At higher compound concentrations, I_tot dropped towards zero, whereas R_h increased to values higher than in pure POPC suspensions (R_h ≈ 60–70 nm), indicating the disintegration of liposomes and formation of larger particles, i.e., various POPC–S aggregates. Nanoliposomes were stable upon the addition of NaPSS and NaPMA, as indicated by the constant R_h and I_tot values. The interaction of CPC, SDS, or TX100 with liposomes was exothermic, while there were no measurable heat effects with NaPSS or NaPMA. The SDS and TX100 increased the number density of EPs several-fold in erythrocyte suspensions and up to 30-fold in the conditioned media of Dunaliella tertiolecta at the expense of the number density of cells, which decreased to less than 5% in erythrocytes and several-fold in Dunaliella tertiolecta. The SDS and TX100 did not affect the number density of the microalgae Phaeodactylum tricornutum, while the number density of EPs was lower in the conditioned media than in the control, but increased several-fold in a concentration-dependent manner. Our results indicate that amphiphilic molecules need to be organized in nanosized particles to match the local curvature of the membrane for facilitated uptake. To pursue this hypothesis, other surfactants and biological membranes should be studied in the future for more general conclusions. Full article

Background: In-home palivizumab administration programs (PH) have shown promise in reducing RSV-associated infections. These programs may be particularly beneficial for children with medical complexity (CMC) by limiting their exposure to healthcare-associated infections (HAIs) from non-RSV-related pathogens during transportation and visits to medical facilities. Methods: In this prospective study, 41 children with CMC less than 2 years of age were randomized by their health insurance to receive PH or in the clinic (PC) during the RSV season (October 2018–April 2019). Patients were stratified by home ventilation. The primary outcome was the total number of face-to-face encounters. Secondary outcomes were unscheduled clinic visits and hospitalizations secondary to the non-RSV LRTIs. Standard frequentist and Bayesian analyses were performed. Results: All demographic factors and strata were matched between PH (“n” = 13, mean age 22 mo. SD ± 1), and PC (“n” = 28, mean age: 18 mo. SD ± 1). There was a decrease in the number of total face-to-face encounters (adjusted for mechanical ventilation and baseline diagnosis) [(4.5 vs. 8.8), (RR: 1.8, 95% CI: 1.3–2.5, p = 0.001)], and hospitalizations [(0.3 vs. 1.25), (RR: 3.8, 95% CI: 1.3–11.3, p = 0.016)], in the PH vs PC groups. Bayesian analysis showed a 93% probability of benefit in favor of fewer face-to-face encounters in the PH group. Conclusions: This study suggests that PH administration may reduce healthcare utilization in CMC. Minimizing exposure to healthcare facilities and supporting home-based interventions are promising strategies for this population. Full article

Background: This study focused on evaluating the physiochemical characteristics and antibacterial activity of Octoprohibitin-encapsulated CNPs (Octoprohibitin-CNPs) against Acinetobacter baumannii. Methods: Octoprohibitin was encapsulated into CNPs via ionotropic gelation with carboxymethyl chitosan (CMC) and low molecular weight chitosan (CS). Octoprohibitin-CNPs were dispersed in phosphate-buffered saline and the release kinetic profile was determined. Then Octoprohibitin-CNPs were examined using field-emission transmission electron microscopy and physicochemical characterization was performed. Antibacterial activity of Octoprohibitin-CNPs against A. baumannii was evaluated. Biofilm inhibition and eradication assays were performed using the crystal violet (CV) staining-based method for biofilm quantification. Results: The average diameter, zeta potential, encapsulation efficiency, and loading capacity of Octoprohibitin-CNPs were 244.5 ± 21.97 nm, +48.57 ± 0.38 mV, and 85.7% and 34.2%, respectively. TEM analysis imaging revealed that Octoprohibitin-CNPs are irregularly shaped, with fewer aggregates than CNPs. Octoprohibitin-CNPs exhibited a biphasic release pattern, characterized by an initial rapid phase followed by a sustained release over time, extending up to 93.68 ± 6.48% total release until 96 h. In vitro, Octoprohibitin-CNPs showed lower cytotoxicity compared to Octoprohibitin alone. Time-kill kinetic and bacterial viability reduction assays showed Octoprohibitin-CNPs exhibited slightly higher antibacterial activity against A. baumannii than Octoprohibitin. Conclusions: Octoprohibitin-CNP-treated A. baumannii exhibited higher levels of morphological deviation, increased membrane permeability, and the production of reactive oxygen species, as well as antibiofilm activity with greater biofilm inhibition and eradication than Octoprohibitin. These findings show that Octoprohibitin-CNPs perform better against A. baumannii compared to Octoprohibitin alone. Full article

Background/Objectives: The aim of this work was to prepare and characterize gastroretentive floating combination tablets (GRCTs) containing 500 mg of amoxicillin trihydrate (AMX) and 125 mg of levofloxacin (LVX) that provide sustained drug release and stability at gastric pH levels for the eradication of resistant Helicobacter pylori. Method: GRCTs were prepared with low-density excipients and hydrophilic swellable polymers, including hydroxypropyl methylcellulose (HPMC) of various viscosities, polyethylene oxide (PEO), and carboxymethylcellulose (CMC), by the direct compression method. The prepared GRCTs were investigated and optimized in terms of pH stability, tablet hardness, floating lag time and total floating time, drug release rate, gel strength. Results: AMX and LVX in GRCT were stable at the HP eradication target pH above 4.0. The effervescent GRCT composition (AMX/LVX/HPMC [4000 cP]/CMC/microcrystalline cellulose/citric acid/sodium bicarbonate/calcium silicate/silicon dioxide/magnesium stearate = 500/125/50/50/125/40/60/30/10/10, w/w) yielded acceptable hardness (>6 kp), reduced floating lag time (<5 s), a long floating duration (>12 h), and sustained release rates of AMX and LVX (>90% until 12 h). This optimized GRCT had a gel strength of 107.33 ± 10.69 g and pH > 4.0, which maintained the tablets’ shape and AMX stability for 12 h. Conclusions: Collectively, the formulated effervescent GRCTs combining AMX and LVX represented a promising candidate dosage form for eradicating resistant H. pylori. Full article

Objective: To better understand the strategies family caregivers of children with medical complexity (CMC) utilize to deal with the stress and challenges associated with caregiving. Methods: We conducted a cross-sectional qualitative study among family caregivers of CMC receiving medical care at a children’s hospital in Western Pennsylvania. Participants completed in-depth, semi-structured interviews focused on how CMC family caregivers approach and manage caregiving-related challenges and stress. Using constant comparative methodology, we inductively analyzed deidentified transcripts for emergent themes. Results: We interviewed 19 participants (89.4% female) with a mean age of 43 years (range 32–54 years). The mean age of the participants’ children was 10.8 years (range 1–20 years). Twelve participants’ children identified as white and four identified as Black. Three central themes regarding CMC caregivers’ stress-coping strategies emerged: (1) maintaining a positive mindset, (2) developing and relying on interpersonal support networks, and (3) making time for self-preservation. All three themes were universally reported (n = 19/19) by our participants. The most common subthemes for each theme, respectively, focused on staying hopeful and celebrating moments of joy; cultivating supportive relationships with family, friends, and fellow CMC family caregivers; and finding pleasure in “little things” (e.g., everyday activities and hobbies). Conclusion: Family caregivers of CMC utilize a multi-faceted approach to cope with the stress and challenges routinely encountered in caring for CMC. This study’s findings could be used to inform future clinical efforts and research directions aiming to improve clinicians’ ability to support CMC caregivers’ well-being. Full article

This study presents a simple, low-cost, and efficient route to obtain zinc oxide by adopting the thermal decomposition method of zinc acetate at 300 (Gr@ZnO_300), 400 (Gr@ZnO_400), 500 (Gr@ZnO_500), and 600 °C (Gr@ZnO_600) for 1 h. The diffraction patterns collected for the samples indicated the majority formation of the hexagonal phase (P63mc) for zinc oxide and residual amounts for graphitic carbon, which has a hexagonal structure of space group P63/mmc. The images collected by scanning electron microscopy (SEM) revealed the formation of sub-microcrystals with elongated rod-shaped morphology, with dimensions between 0.223 and 1.09 μm. The optical and colourimetric properties of the obtained materials indicate the presence of graphitic carbon in the samples, corroborating the analysis by XRD and Raman spectroscopy, with an optical bandgap close to 3.21 eV, and energies of the valence (E_VB) and conduction (E_CB) bands of 2.89 eV and −0.31 eV, respectively. The photocatalytic performance at 20 min of exposure time under UV light of all prepared samples in the decolourisation of rhodamine B (RhB) dye solutions follows the order Gr@ZnO_300 (95.6%) > Gr@ZnO_600 (92.8%) > Gr@ZnO_400 (84.0%) > Gr@ZnO_500 (78.1%), where the photocatalytic performance of Gr@ZnO_300 sample was 16.5 times more effective than the photolysis test. Moreover, the results confirmed that the best performance was archived at pH = 10, and the holes (h⁺) and superoxide (O₂^•−) radicals are the main species involved in the discolouration of RhB dye molecules in an aqueous medium. Finally, the reusability experiment shows high stability of the Gr@ZnO_300 sample as a solid photocatalyst and cycling capability, which obtained total discolouration of RhB of a solution under five cycling experiments of 60 min of exposure to UV light at room temperature. Full article

Diabetic wounds present significant burdens to both patients and the healthcare system due to their prolonged inflammatory phase and adverse microenvironment. Traditional Chinese medicine (TCM), particularly Scutellaria baicalensis extract (SE), has shown promise in wound healing. Herein, sesbania gum (SG) was oxidized and formed hydrogel with carboxymethyl chitosan (CMCS) through the imine bond. Then, SE was loaded into the hydrogel as a wound dressing (CMCS−OSG@SE hydrogel). In vitro experiments demonstrated the mechanical properties and ROS scavenging efficiency of the hydrogel, as well as the release of SE and its biocompatibility. In an vivo study, diabetic mice with S. aureus infection were used, and the CMCS−-OSG@SE hydrogel dressing accelerated wound healing by promoting epidermal regeneration and collagen deposition. This composite polysaccharide hydrogel loaded with SE shows great potential for diabetic wound treatment. Full article

Recently, cellulose and other biomass nanofibers (NFs) have been increasingly utilized in the design of sustainable materials for environmental, biomedical, and other applications. However, the past literature lacks a comparison of the macromolecular and nanofibrous states of biopolymers in various materials, and the advantages and limitations of using nanofibers (NF) instead of conventional polymers are poorly understood. To address this question, hydrogels based on interpolyelectrolyte complexes (IPECs) between carboxymethyl cellulose nanofibers (CMCNFs) and chitosan (CS) were prepared by ele+ctrostatic cross-linking and compared with the hydrogels of carboxymethyl cellulose (CMC) and CS biopolymers. The presence of the rigid CMCNF altered the mechanism of the IPEC assembly and drastically affected the structure of IPEC hydrogels. The swelling ratios of CMCNF-CS hydrogels of ca. 40% were notably lower than the ca. 100–300% swelling of CMC-CS hydrogels. The rheological measurements revealed a higher storage modulus (G′) of the CMCNF-CS hydrogel, reaching 13.3 kPa compared to only 3.5 kPa measured for the CMC-CS hydrogel. Further comparison of the adsorption characteristics of the CMCNF-CS and CMC-CS hydrogels toward Cu²⁺, Cd²⁺, and Hg²⁺ ions showed the slightly higher adsorption capacity of CMC-CS for Cu²⁺ but similar adsorption capacities for Cd²⁺ and Hg²⁺. The adsorption kinetics obeyed the pseudo-second-order adsorption model in both cases. Overall, while the replacement of CMC with CMCNF in hydrogel does not significantly affect the performance of such systems as adsorbents, CMCNF imparts IPEC hydrogel with higher stiffness and a frequency-independent loss (G″) modulus and suppresses the hydrogel swelling, so can be beneficial in practical applications that require stable performance under various dynamic conditions. Full article