Search Results (5,120)

Cystic fibrosis produces viscous mucus in the lung that increases bacterial invasion, causing persistent infections and subsequent inflammation. Pseudomonas aeruginosa and Staphylococcus aureus are two of the most common infections in cystic fibrosis patients that are resistant to antibiotics. One antibiotic approved to treat these infections is levofloxacin (LVX), which functions to inhibit bacterial replication but can be further developed into tailorable particles. Nanoparticles are an emerging inhaled therapy due to enhanced targeting and delivery. The extracellular matrix (ECM) has been shown to possess pro-regenerative and non-toxic properties in vitro, making it a promising delivery agent. The combination of LVX and ECM formed into nanoparticles may overcome barriers to lung delivery to effectively treat cystic fibrosis bacterial infections. Our goal is to advance CF care by providing a combined treatment option that has the potential to address both bacterial infections and lung damage. Two hybrid formulations of a 10:1 and 1:1 ratio of LVX to ECM have shown neutral surface charges and an average size of ~525 nm and ~300 nm, respectively. The neutral charge and size of the particles may suggest their ability to attract toward and penetrate through the mucus barrier in order to target the bacteria. The NPs have also been shown to slow the drug dissolution, are non-toxic to human airway epithelial cells, and are effective in inhibiting Pseudomonas aeruginosa and Staphylococcus aureus. LVX-ECM NPs may be an effective treatment for pulmonary CF bacterial treatments. Full article

A square patch metasurface is designed, simulated, fabricated, and experimentally tested to investigate polarization characteristics quantitatively. The metasurface consists of one layer unit cell in the form of a square patch with one via and a lumped resistor, which is used for harvesting RF (radio frequency) energy. FR4 dielectric is used as a substrate supported by a metal ground plane. Polarization-dependent properties with specific surface current patterns and voltage dip are obtained when simulating under normal incidence of a plane wave. This characteristic results from changes in surface current conditions when the polarization angle is varied. A voltage dip appears at a specific polarization angle when the surface current pattern is symmetrical. This condition occurs when the position of the lumped resistor from the center of the patch is perpendicular to the linearly polarized incident electric field. A couple of 10 × 10 arrays with different resistor positions are fabricated and tested. The experimental results are in good agreement with the simulated results. The proposed design demonstrates a symmetric unit cell structure with one via and a resistor that exhibits polarization-dependent behavior for linear polarization. An asymmetric patch design is explored through both simulation and measurement to mitigate polarization dependence by suppressing the dip behavior, albeit at the expense of reduced absorption efficiency. This study provides a complete polarization analysis for both symmetric and asymmetric patch metasurfaces with a single via and a single lumped resistor, and introduces a predictive relation between the position of the resistor relative to the center of the patch and the resulting voltage dip behavior. Full article

This research focuses on designing polymer membranes as biocompatible materials using home-built electrospinning equipment, offering alternative solutions for tissue regeneration applications. This technological development supports cell growth on biomaterial substrates, including hepatocellular carcinoma (Hep-G2) cells. This work researches the compatibility of polymer membranes (fiber mats) made of polyvinylidene difluoride (PVDF) for possible use in cellular engineering. A standard culture medium was employed to support the proliferation of Hep-G2 cells under controlled conditions (37 °C, 4.8% CO₂, and 100% relative humidity). Subsequently, after the incubation period, electrochemical impedance spectroscopy (EIS) assays were conducted in a physiological environment to characterize the electrical cellular response, providing insights into the biocompatibility of the material. Scanning electron microscopy (SEM) was employed to evaluate cell adhesion, morphology, and growth on the PVDF polymer membranes. The results suggest that PVDF polymer membranes can be successfully produced through electrospinning technology, resulting in the formation of a dipole structure, including the possible presence of a polar β-phase, contributing to piezoelectric activity. EIS measurements, based on R_ct and C_dl values, are indicators of ion charge transfer and strong electrical interactions at the membrane interface. These findings suggest a favorable environment for cell proliferation, thereby enhancing cellular interactions at the fiber interface within the electrolyte. SEM observations displayed a consistent distribution of fibers with a distinctive spherical agglomeration on the entire PVDF surface. Finally, integrating piezoelectric properties into cell culture systems provides new opportunities for investigating the influence of electrical interactions on cellular behavior through electrochemical techniques. Based on the experimental results, this electrospun polymer demonstrates great potential as a promising candidate for next-generation biomaterials, with a probable application in tissue regeneration. Full article

Porosity and roughened surfaces of implant materials have been shown to lead to improved cellular attachment and enhanced osseointegration. These topography changes in the surface also aid in the mechanical interlocking of the material to the bone. Polyetheretherketone (PEEK) has emerged as a popular alternative to titanium-based implants due to its lack of stress-shielding effect, radiolucency, and high chemical resistance. However, PEEK is bioinert, thus requiring surface modifications to elicit appropriate cellular responses that lead to successful osteointegration of the material in vivo. Sulfonation is a process used to modify the surface of PEEK, which can be controlled by varying parameters such as soak time and soak temperature, thereby fabricating a porous surface on the material. This work aimed to ensure the repeatability of a previously optimized sulfonated and hydrothermally treated PEEK surface and subsequently observe the mechanical properties, bacterial attachment, and cellular response of pre-osteoblast MC3T3-E1 cells on the surface. This study found that while all PEEK surfaces had similar cell and Staphylococcus aureus attachment, the sulfonated and hydrothermally treated PEEK (peak mean load of 605 N, p ≤ 0.0001) and the sulfonated only PEEK (peak mean load of 495 N, p = 0.0240) had a higher level of performance in expulsion testing than smooth PEEK due to its mechanical interlocking ability. Imaging and contact angle analysis confirm that a surface with repeatable porosity can be achieved. Full article

The demand for anion exchange membranes (AEMs) is growing due to their applications in water electrolysis, CO₂ reduction conversion and fuel cells, as well as water treatment, driven by the increasing energy demand and the need for a sustainable future. However, current AEMs still face challenges, such as insufficient permeability and stability in strongly acidic or alkaline media, which limit their durability and the sustainability of membrane fabrication. In this study, polyvinyl alcohol (PVA) and chitosan (CS) biopolymers are selected for membrane preparation. Zinc oxide (ZnO) and porous organic polymer (POP) nanoparticles are also introduced within the PVA-CS polymer blends to make mixed-matrix membranes (MMMs) with increased OH⁻ transport sites. The membranes are characterized based on typical properties for AEM applications, such as thickness, water uptake, KOH uptake, Cl⁻ and OH⁻ permeability and ion exchange capacity (IEC). The OH⁻ transport of the PVA-CS blend is increased by at least 94.2% compared with commercial membranes. The incorporation of non-porous ZnO and porous POP nanoparticles into the polymer blend does not compromise the OH⁻ transport properties. On the contrary, ZnO nanoparticles enhance the membrane’s water retention capacity, provide basic surface sites that facilitate hydroxide ion conduction and reinforce the mechanical and thermal stability. In parallel, POPs introduce a highly porous architecture that increases the internal surface area and promotes the formation of continuous hydrated pathways, essential to efficient OH⁻ mobility. Furthermore, the presence of POPs also contributes to reinforcing the mechanical integrity of the membrane. Thus, PVA-CS bio-based membranes are a promising alternative to conventional ion exchange membranes for various applications. Full article

CdTe nanocrystals (NCs) have emerged as a promising active layer for efficient thin-film solar cells due to their outstanding optical properties and simple processing techniques. However, the low hole concentration and high resistance in the CdTe NC active layer lead to high carrier recombination in the back contact. Herein, we developed a novel 2-iodothiophene as a wet etching solution to treat the surface of CdTe NC. We found that surface treatment using 2-iodothiophene leads to reduced interface defects and improves carrier mobility simultaneously. The surface properties of CdTe NC thin films after iodide salt treatment are revealed through surface element analysis, space charge limited current (SCLC) studies, and energy level investigations. The CdTe NC solar cells with 2-iodothiophene treatment achieved power conversion efficiency (PCE) of 4.31% coupled with a higher voltage than in controlled devices (with NH₄I-treated ones, 3.08% PCE). Full article

Background and Objectives: Posterior chamber phakic implantable contact lenses (Phakic-ICL) are widely used for refractive correction due to their efficacy and safety, including minimal corneal endothelial cell loss. The Collamer-based EVO+ Visian implantable contact lens (ICL), manufactured from Collamer, which is a blend of collagen and hydroxyethyl methacrylate (HEMA), has demonstrated excellent long-term biocompatibility and optical clarity. Recently, hydrophilic acrylic Phakic-ICLs, such as the Implantable Phakic Contact Lens (IPCL), have been introduced. This study investigated the material differences among Phakic-ICLs and their interaction with fibronectin (FN), which has been reported to adhere to intraocular lens (IOL) surfaces following implantation. The aim was to compare Collamer, IPCL, and LENTIS lenses (used as control) in terms of FN distribution and cell adhesion using a small number of explanted Phakic-ICLs. Materials and Methods: Three lens types were analyzed: a Collamer Phakic-ICL (EVO+ Visian ICL), a hydrophilic acrylic IPCL, and a hydrophilic acrylic phakic-IOL (LENTIS). FN distribution and cell adhesion were evaluated across different regions of each lens. An in vitro FN-coating experiment was conducted to assess its effect on cell adhesion. Results: All lenses demonstrated minimal FN deposition and cellular adhesion in the central optical zone. A thin FN film was observed on the haptics of Collamer lenses, while FN adhesion was weaker or absent on IPCL and LENTIS surfaces. Following FN coating, Collamer lenses supported more uniform FN film formation; however, this did not significantly enhance cell adhesion. Conclusions: Collamer, which contains collagen, promotes FN film formation. Although FN film formation was enhanced, the low cell-adhesive properties of HEMA resulted in minimal cell adhesion even with FN presence. This characteristic may contribute to the long-term transparency and biocompatibility observed clinically. In contrast, hydrophilic acrylic materials used in IPCL and LENTIS demonstrated limited FN interaction. These material differences may influence extracellular matrix protein deposition and biocompatibility in clinical settings, warranting further investigation. Full article

Hydrogel is widely used as a scaffolding material for tissue engineering due to its excellent cytocompatibility and potential for biofunctionalization. However, its poor mechanical property limits its further application. Fabrication of fiber-reinforced hydrogel composite scaffolds has emerged as a solution to overcome this problem. However, existing strategies usually produce nonporous composite scaffolds, where the interfiber pores are completely filled with hydrogel. This design can hinder oxygen and nutrient exchange between seeded cells and the culture medium, thereby limiting cell invasion and colonization within the scaffold. In this study, sodium alginate (SA) hydrogel was exclusively grafted onto the surface of the constituent fibers of the melt electrowritten scaffold while preserving the porous structure. The grafted hydrogel amount and pore size were precisely controlled by adjusting the SA concentration and the crosslinking ratio (SA: CaCl₂). Experimental results demonstrated that the porous composite scaffolds exhibited superior swelling capacity, degradation ratio, mechanical properties, and biocompatibility. Notably, at an SA concentration of 0.5% and a crosslinking ratio of 2:1, the porous composite scaffold achieved optimal cell adhesion and viability. This study highlights the critical importance of preserving porous structures in composite scaffolds for tissue-engineering applications. Full article

Bioactive glass materials have been used for decades in orthopedic surgery, traumatology, and oral and maxillofacial surgery to repair bone defects. This study aimed to evaluate in vitro the survival and proliferation of MG63 human osteosarcoma-derived cells on S53P4 bioactive glass (BonAlive^® granules). Microscopic visualization was performed to directly observe the interactions between the cells and the material. Osteoblast-like cells were examined on non-adherent test plates, on tissue culture (TC)-treated plates and on the surface of the bioglass to assess the differences. Cell survival and proliferation were monitored using a CCK-8 optical density assay. Comparing the mean OD of MG63 cells in MEM on TC-treated plates with cells on BG, we detected a significant difference (p < 0.05), over each time of observation. The sustained cell proliferation confirmed the non-cytotoxic property of the bioglass, as the cell number increased continuously at 48, 72, 96, and 168 h and even did not plateau after 168 h. Since the properties of bioglasses can vary significantly depending on their composition and environment, a thorough characterization of their biocompatibility is crucial to ensure their effective and appropriate application—for example, during hip and knee prosthesis insertion. Full article

Backgroun/Objectives: Recent pharmaceutical research has increasingly focused on eutectic systems to improve the formulation and delivery of active pharmaceutical ingredients (APIs). This study presents the preparation and characterization of three therapeutic eutectic systems (THEESs) based on ibuprofen and menthol at various molar ratios. Methods: The THEESs were prepared and analyzed by assessing their physicochemical properties and rheological properties were evaluated to determine flow behavior. Cytotoxicity assays were conducted on HaCaT and HepG2 cell lines to assess biocompatibility. Results: All systems formed monophasic, homogeneous, clear and viscous liquids. Key physicochemical properties, including density, refractive index, surface tension, speed of sound and isobaric heat capacity, showed a temperature-dependent, inverse proportional trend. Viscosity followed the Vogel–Fulcher–Tammann equation, and rheological analysis revealed non-Newtonian behavior, which is important for pharmaceutical processing. Notably, cytotoxicity assays revealed that Ibu-M3 and Ibu-M4 showed lower toxicity than pure compounds in HaCaT cells, while Ibu-M5 was more toxic; in HepG2 cells, only Ibu-M3 was less toxic, whereas Ibu-M4 and Ibu-M5 were more cytotoxic than the pure compounds. Conclusions: These findings highlight the potential of ibuprofen–menthol eutectic systems for safer and more effective pharmaceutical formulations. Full article

In the present study, for the first time, a biodegradable and non-toxic polyphosphoramidate glycohydrogel (PPAGHGel) was prepared by crosslinking a polyphosphoramidate glycoconjugate (PPAG) with hexamethylene diisocyanate (HMDI) under mild conditions. Poly(oxyethylene H-phosphonate) (POEHP) was used as a precursor and was converted into PPAG via the Staudinger reaction with glucose-containing azide (2-p-azidobenzamide-2-deoxy-1,3,4,6-tetra-O-trimethylsilyl-α-D-glucopyranose). Then, crosslinking of PPAG was performed to yield PPAGHGel, which was thoroughly characterized. The gel showed a gel fraction of 83%, a swelling degree of 1426 ± 98%, and G″ = 1560 ± 65 Pa. The gel was fully degraded by alkaline phosphatase (400 U/L, pH 9) in 19 days, while hydrolytically, up to 52% degradation was observed under similar conditions. Multivalent studies of the obtained hydrogel with lectin–Concanavalin A were performed. PPAGHGel binds 92% of Concanavalin A within 24 h and the complex remains stable until the amount of glucose reaches 0.3 mM. PPAGHGel acts as a stabilizer for silver nanoparticles (12 nm). SEM shows pores measuring 10 µm (surface) and 0.1 mm (interior) with capillary channels, confirming the gel’s suitability for biosensors, drug delivery, or wound dressings. The cytotoxic (IC50) and cell-adhesive properties of the obtained hydrogel were investigated on human cell lines (HeLa). Antibacterial activity tests were also performed with gel containing silver nanoparticles against skin-associated pathogenic bacteria. The results show that PPAGHGel possesses excellent biocompatibility, non-adhesive properties and antibacterial activity. Full article

The development of ceria (CeO_2−x)-based nanoantioxidants requires fine-tuning of structural and surface properties for enhancing antioxidant behavior in biological environments. In this contest, here ultrasmall water-dispersible CeO_2−x nanoparticles (NPs), characterized by a high Ce³⁺/Ce⁴⁺ ratio, were synthesized in a non-polar solvent and phase-transfer to an aqueous environment through ligand-exchange reactions using citric acid (CeO_2−x@Cit) and post-treatment with dopamine hydrochloride (CeO_2−x@Dopa). The concept behind this work is to enhance via surface engineering the intrinsic antioxidant properties of CeO_2−x NPs. For this purpose, thanks to electron transfer reactions between dopamine and CeO_2−x, the CeO_2−x@Dopa was obtained, characterized by increased surface Ce³⁺ sites and surface functionalized with polydopamine bearing o-quinone structures as demonstrated by complementary spectroscopic (UV–vis, FT-IR, and XPS) characterizations. To test the antioxidant properties of CeO_2−x NPs, the scavenging activity before and after dopamine treatment against artificial radical 1,1-diphenyl-2-picrylhydrazyl (DPPH^·) and the ability to reduce the reactive oxygen species in Diencephalic Immortalized Type Neural Cell line 1 were evaluated. CeO_2−x@Dopa demonstrated less efficiency in DPPH^· scavenging (%radical scavenging activity 13% versus 42% for CeO_2−x@Cit before dopamine treatment at 33 μM DPPH^· and 0.13 mg/mL loading of NPs), while it markedly reduced intracellular ROS levels (ROS production 35% compared to 66% of CeO_2−x@Cit before dopamine treatment with respect to control—p < 0.001 and p < 0.01, respectively). While steric hindrance from the dopamine-derived polymer layer limited direct electron transfer from CeO_2−x NP surface to DPPH^·, within cells the presence of o-quinone groups contributed with CeO_2−x NPs to break the autoxidation chain of organic substrates, enhancing the antioxidant activity. The functionalization of NPs with o-quinone structures represents a valuable approach to increase the inherent antioxidant properties of CeO_2−x NPs, enhancing their effectiveness in biological systems by promoting additional redox pathways. Full article

Background/Objectives: Nanoparticles (NPs) were previously explored as enhancers in electroporation due to their potential to locally amplify electric fields near cell membranes, with gold nanoparticles (AuNPs) in particular showing promise in improving membrane permeability and gene electrotransfer (GET). In this study, we systematically investigated the influence of NP properties—including size, shape, surface functionalization, and material—on electroporation efficacy. Methods: A combined approach using theoretical modeling and experimental validation was employed, encompassing numerical simulations, membrane permeabilization assays, transmission electron microscopy, and GET efficiency measurements. Results: Numerical results revealed that the presence of NPs alters local electric field distributions, but the amplification is highly localized, regardless of NP conductivity or geometry. Experimentally, only two out of six tested NP types produced a statistically significant, yet modest, increase in membrane permeability at one electric field intensity. Similarly, GET improvement was observed with only one NP type, with no dependence on concentration or functionalization. Conclusions: Overall, our findings demonstrate that NPs, under tested conditions, do not substantially enhance cell membrane permeability or GET efficacy. These conclusions are supported by both computational modeling and in vitro experiments. Full article

This study explores the valorization of agro-industrial by-products—riceberry broken rice (RBR) and soybean meal (SBM)—as cost-effective substrates for enhancing exopolysaccharide (EPS) production by Bacillus tequilensis PS21. Eight Bacillus strains were screened, and B. tequilensis PS21 demonstrated the highest EPS yield (2.54 g/100 mL DW). The EPS displayed a strong antioxidant capacity with 65.5% DPPH and 80.5% hydroxyl radical scavenging, and a FRAP value of 6.51 mg Fe²⁺/g DW. Antimicrobial testing showed inhibition zones up to 10.07 mm against Streptococcus agalactiae and 7.83 mm against Staphylococcus aureus. Optimization using central composite design (CCD) and the response surface methodology (RSM) revealed the best production at 5% (w/v) RBR, 3% (w/v) SBM, pH 6.66, and 39.51 °C, yielding 39.82 g/L EPS. This EPS is a moderate-molecular-weight (11,282 Da) homopolysaccharide with glucose monomers. X-ray diffraction (XRD) showed an amorphous pattern, favorable for solubility in biological applications. Thermogravimetric analysis (TGA) demonstrated thermal stability up to ~250 °C, supporting its suitability for high-temperature processing. EPS also exhibited anticancer activity with IC₅₀ values of 226.60 µg/mL (MCF-7) and 224.30 µg/mL (HeLa) at 72 h, reduced colony formation, inhibited cell migration, and demonstrated anti-tyrosinase, anti-collagenase, and anti-elastase effects. This study demonstrates the successful valorization of agro-industrial by-products—RBR and SBM—for the high-yield production of multifunctional EPS with potent antioxidant, antimicrobial, and anticancer properties. The findings highlight the sustainable potential of these low-cost substrates in supporting the development of green and value-added bioproducts, with promising utilizations across the food, pharmaceutical, and cosmetic sectors. Full article

In the context of critical challenges in curcumin-modified polyurethane synthesis—including limited curcumin bioavailability and suboptimal biodegradability/biocompatibility—a novel polyurethane material (Cur-PU) with good mechanical, shape memory, pH-responsive, and biocompatibility was synthesized via a one-pot, two-step synthetic protocol in which HO-PCL-OH served as the soft segment and curcumin was employed as the chain extender. The experimental results demonstrate that with the increase in Cur units, the crystallinity of the Cur-PU material decreases from 32.6% to 5.3% and that the intensities of the diffraction peaks at 2θ = 21.36°, 21.97°, and 23.72° in the XRD pattern gradually diminish. Concomitantly, tensile strength decreased from 35.5 MPa to 19.3 MPa, and Shore A hardness declined from 88 HA to 65 HA. These observations indicate that the sterically hindered benzene ring structure of Cur imposes restrictions on HO-PCL-OH crystallization, leading to lower crystallinity and retarded crystallization kinetics in Cur-PU. As a consequence, the material’s tensile strength and hardness are diminished. Except for the Cur-PU-3 sample, all other variants exhibited exceptional shape-memory functionality, with R_f and R_r exceeding 95%, as determined by three-point bending method. Analogous to pure curcumin solutions, Cur-PU solutions demonstrated pH-responsive chromatic transitions: upon addition of hydroxide ion (OH⁻) solutions at increasing concentrations, the solutions shifted from yellow-green to dark green and finally to orange-yellow, enabling sensitive pH detection across alkaline gradients. Hydrolytic degradation studies conducted over 15 weeks in air, UPW, and pH 6.0/8.0 phosphate buffer solutions revealed mass loss <2% for Cur-PU films. Surface morphological analysis showed progressive etching with the formation of micro-to-nano-scale pores, indicative of a surface-erosion degradation mechanism consistent with pure PCL. Biocompatibility assessments via L929 mouse fibroblast co-culture experiments demonstrated ≥90% cell viability after 72 h, while relative red blood cell hemolysis rates remained below 5%. Collectively, these findings establish Cur-PU as a biocompatible material with tunable mechanical properties, and pH responsiveness, underscoring its translational potential for biomedical applications such as drug delivery systems and tissue engineering scaffolds. Full article