Search Results (719)

To induce embryogenic callus from Pinus thunbergii vegetative organs, and deeply understand the internal mechanism of the process, an orthogonal experimental design of three factors and four levels and proteome analysis were adopted. The results showed that the optimal medium was douglas-fir cotyledon medium (DCR), containing 2.5 mg L⁻¹ 2-4-dichlorophenoxyacetic acid (2,4-D) and 1.0 mg L⁻¹ 6-benzylaminopurine (6-BA), 0.3 g L⁻¹ polyvinylpyrrolidone (PVP), 0.5 g L⁻¹ acid casein hydrolysate (CH), 0.5 g L⁻¹ L-glutamine, 1.0 g L⁻¹ inositol, 6.0 g L⁻¹ agar and 20.0 g L⁻¹ sucrose. Microscopic examinations revealed a distinct embryogenic-like callus (EC) structure, and these ECs finally achieved redifferentiation. Analysis of the interactions between factors detected that although the 6-BA concentration alone was not significant, it became a significant effect factor when interacted with 2,4-D (p < 0.05). Peroxidase (POD), superoxide dismutase (SOD) and soluble sugar (SS) of EC were significantly higher than those of non-embryogenic callus (NEC), and label-free quantitative proteomics analysis showed that different types of PODs including peroxidase 4, phospholipid hydroperoxide glutathione peroxidase, and cationic peroxidase 1 in EC were significantly up-regulated, and they were involved in antioxidant biological processes, located in the intercellular region, and performed molecular functions such as heme binding, so POD was a suitable and stable physiological marker for EC. Four up-regulated proteins in EC included glutathione S-transferase, chalcone flavanone isomerase, phosphoenolpyruvate carboxykinase and endoglucanase. Five EC-specific proteins included indole-3-acetic acid-amido synthetase GH3.1, indole-3-acetate O-methyltransferase 1-like, cytokinin dehydrogenase, MLP-like protein 423 and 2-methoxy-6-polyprenyl-1,4-benzoquinol methylase. These proteins are also potential EC molecular markers. Among these proteins, glutathione S-transferase is beneficial to prevent cell death in EC, while indole-3-acetate O-methyltransferase 1-like and cytokinin dehydrogenase are beneficial to promote EC redifferentiation. Full article

This work describes an efficient and environmentally friendly method for the synthesis of silver-based nanostructures through a green route using Aloe vera extract as a reducing agent, silver nitrate (AgNO₃) as a precursor, and polyvinylpyrrolidone (PVP, 10 kDa molecular weight) as a stabilizing agent. The formation of these structures was supported by UV–Vis spectroscopy, where a surface plasmon resonance (SPR) band was observed between 425 and 460 nm. Scanning electron microscopy revealed predominantly spherical features in the 300–500 nm range; however, the distinction between primary nanoparticles and aggregates cannot be conclusively established from SEM alone. EDX analysis indicated a silver content of 59.96 wt%. Antibacterial assays performed in Z8 medium demonstrated a reduction in cyanobacterial growth with increasing dosage, with complete inhibition observed at ≥20 $\mu$L (nominal MIC = 1.77 mg mL⁻¹, based on precursor estimation). Total dissolved solids and absorbance measurements exhibited a decreasing trend with increasing concentration (effect size = 0.87, $p<0.001$), supporting an inhibitory effect under the tested conditions. These findings suggest potential antibacterial activity. However, this study should be considered exploratory, and further work is required to elucidate the underlying mechanisms. Full article

Paracetamol (PA) ranks among the most frequently prescribed over-the-counter analgesic and antipyretic agents worldwide; nonetheless, overdose scenarios are associated with severe hepatotoxic and nephrotoxic consequences, while its incomplete metabolic removal renders it a persistent micropollutant in surface and wastewater systems. These concerns underscore the urgent need for rapid, cost-efficient, and highly sensitive analytical tools capable of quantifying PA at trace levels in complex matrices. In the present study, spherical gold nanoparticles (AuNPs) were fabricated through an environmentally benign route exploiting an aqueous extract of Juniperus sp. leaves as the reducing and capping agent, with polyvinylpyrrolidone (PVP) serving as an additional colloidal stabilizer. The resulting nanoparticles were immobilized on a glassy carbon electrode to construct an AuNPs/PVP/GCE sensing platform. Physicochemical characterization by UV–Vis spectroscopy, dynamic light scattering (DLS), and transmission electron microscopy (TEM) verified the spherical morphology, narrow size distribution, and colloidal stability of the synthesized AuNPs, and further confirmed a 3.5-fold enlargement of the electroactive surface area relative to the unmodified electrode. Under fully optimized conditions, the fabricated sensor delivered a well-defined linear voltammetric response toward PA oxidation across the concentration interval of 0.05–0.31 µM (R² = 0.9939), with a limit of detection of 0.024 µM and a limit of quantification of 0.080 µM. The sensor retained its analytical accuracy in the presence of common co-existing species, including ascorbic acid, uric acid, dopamine, caffeine, ibuprofen, and adrenaline. Quantitative determination of PA in commercial tablet formulations via the standard addition approach yielded results in close agreement with the declared content, confirming the practical suitability of the AuNPs/PVP/GCE platform for routine pharmaceutical quality control. Full article

Platinum and palladium nanoparticles (Pt- and Pd-NPs) were synthesized using a green reduction approach with ascorbic acid (AA) or saponin from Quillaja bark (Qb) as reducing agents and stabilized with conventional polymers (PVP, polyvinylpyrrolidone, PEG, polyethylene glycol) or natural surfactants (CG (coco glucoside), Qb). The influence of stabilizer type on reduction efficiency, particle size, and colloidal homogeneity was investigated. Pt-NPs exhibited consistently high reduction efficiencies (>87%) in all systems, whereas Pd-NPs showed lower efficiencies and greater sensitivity to synthesis conditions. AFM and DLS analyses confirmed the formation of particles within the nanometric range. In AA-based systems, Pt-NPs were generally smaller than Pd-NPs, while the opposite trend was observed in Qb-based systems. Natural surfactants provided effective NP stabilization, low values of polydispersity index (PdI), good size control, and stable nanostructures. The results demonstrated that biosurfactant-based stabilizers, particularly CG and Qb, can successfully replace synthetic polymeric stabilizers in the green synthesis of noble metal NPs, supporting the development of more sustainable and environmentally friendly synthesis approaches. Full article

Gabiroba (Campomanesia adamantium (Cambess.) O. Berg) is a native fruit tree of the Brazilian Cerrado biome with notable economic potential and phytotherapeutic properties. However, commercial seedling production is limited by the recalcitrant nature of its seeds and vegetative propagation is further constrained by phenolic compound oxidation. Therefore, this study evaluated the effects of antioxidant treatments on sprouting, cutting survival, callus formation and attempted adventitious rooting of C. adamantium cuttings collected in different seasons. The experiment was conducted in a greenhouse at the Federal University of Jataí using cuttings collected from an experimental orchard. Eleven treatments were evaluated: a control and different concentrations of ascorbic acid (AA; 10, 20, and 40 mg L⁻¹), phloroglucinol (FLO; 50, 100, and 200 mg L⁻¹), and polyvinylpyrrolidone (PVP; 100, 200, 400, and 600 mg L⁻¹). After 60 days, sprouting, cutting survival, callus formation, rooting, and the number of old and new leaves were assessed. Data were subjected to analysis of variance, and means were compared using the Scott–Knott test. Antioxidant treatments did not promote rhizogenesis in C. adamantium cuttings. Nevertheless, the season influenced sprouting, survival, and callus formation, especially during summer and autumn. These results indicate that antioxidant application alone is insufficient to overcome rooting recalcitrance in this species, although it may affect early developmental responses of the cuttings under specific seasonal conditions. Full article

The demand for sustainable, high-performance biomaterials has driven intense research towards natural polysaccharide hydrogels. Accordingly, this study aimed to synthesize novel starch-based hydrogel materials, considering their inherent hydrogel-forming capabilities together with diverse potential applications (e.g., pharmaceuticals, medicine, and the cleaning application for the artifacts). To obtain hydrogels with enhanced mechanical and physico-chemical properties, starch was combined with other polymeric species (i.e., alginate, polyvinyl alcohol, and polyvinylpyrrolidone), and a gelling process was induced by using calcium cations or borate anions. Two distinct hydrogels (named S-Ca and S-SB, respectively) were prepared and characterized by a range of instrumental and experimental techniques. The assessed properties included water and solvent resistance, equilibrium water content, water-releasing capacity, morphology and microstructural features with their composition by SEM-EDS analysis, and mechanical properties (tensile strength, elasticity, Young’s modulus, and hardness). The results indicated that the investigated hydrogels exhibited suitable properties for a variety of applications, including surface cleaning processes in the field of cultural heritage conservation. For instance, they showed equilibrium water content (between 80 and 90%) comparable with other hydrogels commonly used as cleaning tools (e.g., agar and p(HEMA)/PVP) and quite low water-releasing capacity (between 10 and 17 mgcm⁻²). Moreover, the S-SB hydrogel displayed distinctly better tensile strength and elongation at break than hydrogel prepared in the presence of Ca²⁺ (S-Ca). Notably, S-SB experienced considerable elasticity improvement after freezing–thawing cycles, as indicated by a decrease in tensile strength (from 275 to 102 kPa) and an increase in elongation at break (from 121 to 275%). However, it should be noted that the hydrogel selection depends on the requirements of the target application, as different processes demand materials with distinct characteristics. Hence, both S-Ca and S-SB hydrogels were tested as cleaning tools for the removal of artificially aged acrylic coating (i.e., Paraloid B-72) from the surface of marble and wood specimens, respectively. The tests provided positive results, as aged coating was satisfactorily removed by applying the hydrogels loaded with a nanostructured emulsion (NSE). These novel starch-based hydrogels demonstrate significant potential as high-performance alternatives to conventional hydrogel systems currently used in conservation science as well as in other industrial applications. Full article

Background: Thymoquinone (TQ), a bioactive compound derived from Nigella sativa L., exhibits promising antioxidant, anti-inflammatory, and wound-healing properties; however, its clinical application is limited by poor solubility and instability. Methods: In this study, three electrospun nanofiber systems based on different polymeric matrices, PVP (N1), PVP/HPβCD (N2), and PVP/PCL (N3), were developed as potential wound dressing materials for controlled TQ delivery. Results: All formulations produced uniform nanofibrous structures with TQ molecularly dispersed within the polymer matrix, as confirmed by SEM, XRPD, and FTIR analyses. The composition of the nanofibers significantly influenced their physicochemical and functional properties. The N2 system, containing hydroxypropyl-β-cyclodextrin (HPβCD), exhibited the smallest fiber diameter (~208 nm), the fastest drug release, and enhanced antioxidant and anti-inflammatory activity due to improved TQ solubility. In contrast, the N3 system, incorporating polycaprolactone (PCL), formed thicker fibers (~1089 nm) and demonstrated sustained release behavior, the highest mucoadhesion, and the most pronounced wound-healing effect (90% closure after 24 h). Stability studies revealed that HPβCD significantly improved TQ resistance to thermal, humidity, and photolytic degradation, whereas the PVP-based system without stabilizers showed the lowest stability. Principal component analysis (PCA) confirmed that nanofiber performance is governed by two key factors: drug availability and sustained release combined with bioadhesion. Importantly, wound-healing efficiency correlated more strongly with the latter. Conclusions: The results demonstrate that rational design of polymer composition enables modulation of TQ delivery and biological response. Among the tested systems, PVP/PCL nanofibers appear to be the most promising candidates for wound-dressing applications due to their ability to provide sustained drug release and enhance tissue regeneration. Full article

This study produced and analyzed composite membranes composed of polysulfone (PSf), polyvinylpyrrolidone (PVP) and Metal–Organic Framework (ZIF-8) for treating effluent generated by the Batik industry. The incorporation of ZIF-8 was performed to enhance membrane efficiency. The findings indicated that ZIF-8 markedly enhanced hydrophilicity and pure water flux of membranes. The M-0.5 membrane containing 0.5 g of ZIF-8 demonstrated superior performance, with a water contact angle of 49.4° and a porosity of 83.5%. In contrast, the ZIF-8-free membrane (M-0) displayed a water contact angle and porosity of 66.3° and 76.7%, respectively. These combined characteristics enabled the M-0.5 membrane to achieve the highest pure water flux of 197.1 L m⁻² h⁻¹ at 5 bar. All membranes attained complete total suspended solids (TSS) rejection at 100% efficiency. Turbidity rejection rates ranged from 75% to 92%, whilst color rejection rates ranged from 65.7% to 87.6%. The maximum chemical oxygen demand (COD) rejection observed was 57.9%, achieved by the M-0.25 membrane (0.25 g of ZIF-8) at an operational pressure of 4 bar. Meanwhile, for permeability and hydrophilicity, the ideal loading is 0.5 g of ZIF-8 (M-0.5). This concentration yielded the optimal equilibrium of porosity (83.5%), the minimal water contact angle (49.4°), and the maximal pure water flux (197.1 L m⁻² h⁻¹). Nonetheless, the TDS rejection rate was rather low at 8.0–21.1%. The membrane effectively preserved effluent pH stability between 7.9 and 8.3. The aggregation of ZIF-8 at elevated concentrations diminished mechanical strength and selectivity. Additional optimization is required to equilibrate these performance indicators. Full article

The amniotic membrane is widely recognized in regenerative medicine due to its rich content of extracellular matrix proteins and growth factors that confer anti-inflammatory and pro-regenerative properties. However, its rapid degradation restricts its standalone clinical use. To overcome these limitations, we developed biofilms by incorporating decellularized human amniotic membrane matrix (dHAM) into polycaprolactone (PCL) and polyvinylpyrrolidone (PVP) matrices using spin-coating. Bone marrow-derived mesenchymal stem cells (BM-MSCs) were used to evaluate film biocompatibility through cell viability, proliferation, and wound healing migration assays. Surface characterization was performed using contact angle measurements, Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy, and scanning electron microscopy. Soluble dHAM extracts (4–6 mg/mL) significantly enhanced BM-MSC proliferation at 48 h compared to controls (p ≤ 0.01 and p ≤ 0.0001). Both PCL-dHAM and PVP-dHAM biofilms exhibited high cell viability (>90%) and improved initial adhesion. Notably, dHAM incorporation significantly increased wound closure rates at 24 h, reaching 98.47% for PCL-dHAM and 93.13% for PVP-dHAM, compared to 76.56% and 64.20% for pure polymers (p = 0.0001). All scaffolds maintained hydrophilic surfaces (<90°), favorable for cell interaction. The integration of dHAM into PCL and PVP by spin-coating produces biofilms biocompatible with enhanced regenerative potential, representing promising candidates for wound healing applications. In conclusion, these coatings support BM-MSC adhesion, proliferation, and migration, while significantly accelerating wound closure, underscoring their value as advanced bioactive coatings for regenerative medicine. Full article

Acid phosphatase (ACP) is a clinically important enzyme whose early-stage detection is hindered by its extremely low abundance, nonspecific tissue distribution, and rapid loss of activity under conventional analytical conditions. Herein, we present a target-driven in situ nanozyme synthesis strategy that enables rapid and ultrasensitive point-of-care testing (POCT) of ACP. In this approach, ACP catalyzes the hydrolysis of L-ascorbic acid 2-phosphate sesquimagnesium (AAPS), producing ascorbic acid (AA). The generated AA partially reduces Fe³⁺ ions to Fe²⁺, thereby initiating alkaline co-precipitation and in situ formation of Fe₃O₄ nanoparticles. Polyvinylpyrrolidone (PVP) stabilizes the nanoparticles and preserves catalytic accessibility, while their intrinsic magnetism allows for efficient magnetic separation to eliminate matrix interference. The resulting Fe₃O₄@PVP nanozymes display pronounced peroxidase-like activity, catalyzing hydrogen-peroxide-mediated oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB). Quantitative readout can be achieved using either spectrophotometric analysis or smartphone imaging. The sensing platform achieves a detection limit of 0.021 U/L within 40 min and demonstrates excellent sensitivity, selectivity, and operational robustness. Successful validation in human serum confirms its clinical feasibility, while smartphone-based imaging enables portable and low-cost quantification suitable for decentralized diagnostics. Collectively, this work establishes a generalizable paradigm for target-triggered nanozyme generation aimed at detecting low-abundance and labile biomarkers. Full article

Background: Polymeric drug-eluting films are promising platforms for local antibacterial delivery, but their release profiles depend strongly on the permeability and morphology of the barrier layer. Here, the previously proposed concept of additively manufactured PLACE (Printed Layered Adjustable Cargo Encapsulation) coatings was extended from "single orifice"-defined release toward porosity-assisted barrier control. Two conventional water-soluble porogens, polyethylene glycol (PEG) and polyvinylpyrrolidone (PVP), were compared with poly(2-ethyl-2-oxazoline) (PEOx), a hydrophilic polymer proposed as an alternative to PEG in biomedical formulations, but whose use as a leachable porogen has received little attention. Methods: Each porogen was introduced into the upper PLGA barrier of multilayer PLACE films. The resulting films were characterized for film formation, post-hydration morphology by SEM, release of methylene blue and vancomycin, and antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). Results/Conclusions: PEG was poorly compatible with PLGA and mainly produced surface-localized defects rather than a barrier with controlled permeability suitable for prolonged delivery. PVP K17 provided sustained release at 10 wt.%, whereas 20 wt.% PVP caused burst-dominated release and stronger morphological disruption. PEOx formed developed porosity at lower loading and produced release regimes ranging from several days to approximately two weeks. Vancomycin-loaded films containing 5 wt.% PEOx enabled near-complete release over two weeks while preserving film integrity and showed pronounced early anti-MRSA activity. These results identify porogen selection as a key formulation step and support PEOx as a useful porogen for early high-output antibacterial PLACE coatings. Full article

Dissolving microneedles (DMN) could be considered as a minimally invasive alternative for transdermal delivery of naltrexone hydrochloride (NTX). In the present study, DMN patches with smart design were developed via a two-step micromoulding technique. The systems were composed of drug-free polyvinylpyrrolidone (PVP) and polyvinyl alcohol (PVA) blend microneedle tips, combined with a drug-loaded backing layer based on PVP and Poloxamer 407. The influence of polymer concentration in DMN tips and backing-layer composition on morphology, mechanical properties, drug release and permeation was evaluated. Mechanical studies revealed that intermediate polymer concentration (formulation MN-20%/2:1) provided superior structural integrity (13.57 ± 1.43% height reduction after compression) and efficient penetration up to the fourth Parafilm^® layer. Incorporation of NTX into the backing layer allowed for high drug loading, while a 2:1 PVP:P407 ratio provided higher toughness (1806 g/mm) as well as thermoresponsive and controlled drug release. In vitro permeation studies demonstrated significantly enhanced NTX delivery from DMN systems compared to simple matrix patches—an almost 4-fold increase in flux with 56% permeation of NTX up to 8 h. These findings highlight the importance of polymer composition in DMN design and demonstrate the potential of the developed systems as an effective platform for transdermal delivery of NTX. Full article

The interfacial behavior of hybrid nanoparticles on biological substrates governs their functional performance. Here, we investigate how surface properties and colloidal stability dictate the pH-dependent adhesion of oxybenzone-loaded palygorskite nanohybrids to hair—a model biological interface. A series of hybrids with 5–50% oxybenzone loadings were prepared via melt impregnation. XRD and FTIR analyses confirm hydrogen bonding between oxybenzone and palygorskite, forming stable organic–inorganic hybrids. The colloidal stability of these nanohybrids varies non-monotonically with oxybenzone loading, governed by surface hydrophilicity and zeta potential, exhibiting a network-like behavior upon pH change. Optimal stability is achieved at an intermediate loading with a favorable balance of surface properties. While pristine hybrids show no affinity for hair, surface modification with cationic polyquaternium-7 (PQ-7) or non-ionic polyvinylpyrrolidone (PVP) enables effective deposition through distinct pH-dependent mechanisms: PQ-7 operates optimally at pH 10 via electrostatic attraction, whereas PVP performs best at pH 4 through hydrogen bonding, forming a protective coating layer on the hair surface. Deposition fails for PVP-modified hybrids at 50% loading due to excessive surface hydrophobicity. The deposited hybrids provide exceptional UV protection, significantly mitigating cuticle damage, suppressing photo-yellowing, and minimizing protein oxidation. Among the hybrids, hybrid-35 exhibited the best colloidal stability, whereas PQ-7-modified hybrid-50 gave the highest UV protection (color difference ΔE reduced from 10.51 to 1.60). The adhesion rates of the two best-performing hybrids were 2.70% and 2.85%, respectively. Beyond hair protection, we evaluate the environmental interface of these materials. While free oxybenzone is highly toxic to Chlorella vulgaris, hybridization drastically reduces its ecotoxicity. Remarkably, palygorskite and the hybrids promote algal growth, likely by acting as nutrient adsorbents and attachment sites. This work provides fundamental insights into particle–biointerface interactions and offers a strategy for designing functional hybrid materials with tailored surface properties for bio-related applications. Full article

Nanomaterials with multiple enzyme-like activities offer significant opportunity for constructing multifunctional sensing methods. In this work, a hydrangea flower-like cerium dioxide nanomaterial (CeO₂ NF) with both peroxidase (POD)- and hydrolase-like activities, which was surface-modified by polyvinylpyrrolidone (PVP) in situ, was prepared through an oil bath method. Based on the POD-like activity of CeO₂ NFs, an “on-off” fluorescence method was established for chiral recognition of arginine (Arg) enantiomers. Meanwhile, utilizing the hydrolase-like activity of CeO₂ NFs and their synergistic interaction with alkaline phosphatase (ALP), an “on-off-on” fluorescence method was developed for the detection of p-nitrophenol (p-NP) and ALP. The sensor demonstrated excellent chiral selectivity for Arg enantiomers, with a high enantiomeric factor (ef) of up to 2.48, allowing for the quantitative detection of L-Arg in the range of 770–940 μM, with a limit of detection (LOD) of 26.00 μM. Furthermore, it exhibited high sensitivity for p-NP and ALP detection, with linear ranges of 10.0–84.3 μM and 300–2000 mU/mL, and LODs of 7.07 μM and 200 mU/mL, respectively. Through an enzyme kinetic analysis, fluorescence lifetime measurement, zeta potential analysis, and density functional theory (DFT) calculations, the underlying catalytic and chiral recognition mechanisms were proposed. Finally, the method was validated through the accurate detection of L-Arg, p-NP, and ALP in real samples (rabbit plasma, food-grade amino acid, and water samples). Full article

Background: Hot-melt extrusion (HME) is a promising technology for the manufacturing of drug products; however, its application is limited by elevated thermal and shear stresses that may induce degradation of thermolabile active pharmaceutical ingredients. One of the approaches to reducing processing temperatures is the use of polymeric systems with tailored thermal and rheological properties. The aim of the study was to develop an approach for the design of polymeric systems exhibiting a transient plasticization window, enabling a reduction in melt viscosity and improved processability under low-temperature extrusion conditions, followed by the formation of a structurally coherent matrix upon cooling. Methods: The compatibility of the initial polymers was assessed using laser microinterferometry. Based on the obtained data, three- and four-component polymeric compositions were designed and prepared by hot-melt extrusion. The resulting materials were characterized by differential scanning calorimetry, melt rheology analysis, and storage stability assessment. Thermal and rheological data were used to iteratively optimize the polymeric systems. Results: A four-component polymeric system based on PVP K-29/32, PEG 400, PEG 1500, and HPC EF was developed, suitable for processing by hot-melt extrusion at 70 °C. The final system enabled formation of a homogeneous extrudate, exhibited reproducible rheological behavior, and remained stable in the solid-state during storage, with no evidence of cold flow. Conclusions: It was established that, in the design of polymeric systems for hot-melt extrusion, the key factor is not achieving the lowest possible glass transition temperature, but rather the design of a system in which viscosity is transiently reduced under processing conditions and followed by structural stabilization upon cooling. The proposed approach may be applied in the development of polymeric premixes for the preparation of dosage forms by hot-melt extrusion, including those incorporating thermolabile active pharmaceutical ingredients. Full article