Search Results (395)

The growing need for effective antimicrobial polymeric materials has prompted extensive development of functional chitosan derivatives with enhanced physicochemical and biological properties. In this work, the conjugates of chitosan with 4-anisaldehyde (ChT-AA) were synthesised through Schiff base formation at various molar ratios and characterised using FT-IR, ¹H NMR, and thermal analysis techniques (TGA/DSC). The spectral data confirmed the successful formation of imine (C=N) linkages and the incorporation of aromatic anisaldehyde fragments into the chitosan structure. Thermal analysis demonstrated increased stability and a higher glass transition temperature for ChT-AA compared with native chitosan, indicating reduced polymer chain mobility and enhanced structural rigidity. Viscoelastic gels based on the synthesised ChT-AA (1:3) and methylcellulose were prepared and evaluated for their rheological properties and antimicrobial performance. Rheological studies revealed non-Newtonian shear-thinning behaviour of these gels with pronounced thixotropy, confirming reversible network recovery after shear deformation. Antimicrobial evaluation of chitosan, its 4-anisaldehyde conjugate (ChT–AA, 1:3), and free 4-anisaldehyde revealed distinct activity patterns. The gels showed no inhibition in the disk diffusion assay, likely due to limited diffusion of the active components. In liquid media, both ChT and ChT–AA exhibited identical minimum inhibitory concentrations (MICs) against E. coli (0.313 mg/mL) and C. albicans (1.250 mg/mL), whereas ChT–AA showed two-fold stronger activity against S. aureus (0.313 mg/mL vs. 0.625 mg/mL for ChT). Free 4-anisaldehyde was most active against S. aureus (MIC = 0.175 mg/mL) but less effective against the other strains, confirming its narrower spectrum. These results indicate moderate antimicrobial efficacy in solution but limited activity in gel form due to restricted diffusion. Full article

Biodegradable Pickering emulsions are attracting increased appeal owing to their promising and diversifying therapeutic applications. In this study, for the first time, a novel therapeutic Pickering emulsion stabilized with ginger powder (GA4) was formulated, characterized, and tested for doxorubicin (DOX) delivery. GA4_Pes physicochemical characterization by DLS (Dynamic Light Scattering), POM (Polarized Optical Microscopy), Cryo-SEM (Cryo-Scanning Electron Microscopy), TEM (Transmission Electron Microscopy), and rheology testing confirmed stability for at least one month, solid-like gel properties, and multiple morphology even at a low concentration of stabilizer. In addition, the morphological, dimensional, and rheological properties of some GA4_Pe loaded with DOX (GA4_Pe@DOX) were examined. These formulations were of the w/o/w type, stable for at least 28 days, and showed efficient doxorubicin internalization. A 24 h in vitro release assay displayed a sustained and pH-dependent release, with 30% and 50% chemotherapeutic released at pH 7.4 and 5.6, respectively. Furthermore, in vitro cell viability assessment performed using GA4_Pe showed no toxicity on immortalized 3T3 mouse embryonic fibroblasts but a small significant inhibitory effect on human breast cancer cell line MCF7. Interestingly, the GA4_Pe@DOX emulsion exerted a cytotoxic effect on MCF7 cells very similar to that of the free DOX solution with the same doses of DOX loaded in the same emulsion. Therefore, the total biocompatibility/biodegradability, good drug entrapment, and high stability, as well as the prolonged release and anti-tumor efficacy maintenance of the loaded drug, suggest a feasible application of ginger powder-based Pickering emulsions for topical delivery as a selective therapeutic platform in targeted formulations of antineoplastic drugs. Full article

This study emphasizes overcoming the challenges of targeted drug delivery in colon cancer therapy by developing gastrointestinal (GI) stable, pectin-coated nanoliposomes for the oral delivery of Apigenin-Cyclodextrin Complex as an in situ gel formation. Initially, the formulation was strategically designed using design expert software for formulation optimization. FTIR and XRD studies were conducted to ensure physical compatibility and to confirm the encapsulation of apigenin within the formulation. In process optimization, among all seventeen formulations run tested, PNL (Api-Cy)-13 was identified for the highest drug loading, favourable size dimension of particle with zeta potential, and spherical external morphology through SEM analysis. The metered drug release during an in vitro study for PNL (Api-Cy)-13 was remarkably high (more than 75% of drug availability in the colonic environment, precisely in contrast to only 20% in the gastric phase in a sustained release manner), focused on colon drug targeting as an in situ gel. Furthermore, apigenin release from PNL (Api-Cy)-13 in an ex vivo chick ileum permeability study was observed both in the absence and presence of 1% vancomycin. An incremental apigenin release in the absence of the antibiotic (1% vancomycin) indicated gut microbial-associated and pectinase-mediated drug release. Here, pectin degradation materializes by the colonic microbial environment, which facilitates desirable incremental colonic drug permeation. Finally, an in vitro MTT assay and a competitive flowcytometric cell uptake study with PNL (Api-Cy)-13 using HCT-116 cells proved significant superiority in cytotoxicity profile for apigenin when delivered as an optimized coated nanoliposome in comparison to free apigenin or other non-modified nano-formulation. Also, the inhibition of the cell efflux process was validated by Multidrug Resistance 1 (MDR1) gene regulation. These observations establish an undoubted promise for the novel biopolymer, pectin-based apigenin-cyclodextrin nanoliposomes as targeted therapy in colon cancer with significant in vivo pharmacokinetics and safety profile. Full article

Hydrogels have attracted considerable attention as biomedical materials owing to their distinctive properties; however, improvements in mechanical strength, biodegradability, and biocompatibility remain essential for advanced clinical applications. This study developed a new dual-crosslinked hydrogel based on gelatin (Gel) and dextran (Dex) via sequential aldimine condensation and photopolymerization. Natural Gel and Dex were functionalized to synthesize methacrylated Gel (GelMA) and oxidized Dex (ODex), respectively. An imine-linked network was initially formed between GelMA and ODex via aldimine condensation, followed by a second crosslinked network generated through blue-light-induced free-radical polymerization of GelMA, yielding dual-crosslinked hydrogels (GMODs). ¹H NMR and FT–IR analyses confirmed the successful functionalization and formation of dual-crosslinked structure. The dual-crosslinked network enhanced the thermal stability and water-retaining capacity of the freeze-dried hydrogels (DGMODs) while reducing the surface wettability and equilibrium swelling ratio of GMODs. The maximum compressive strength (σₘ) increased with crosslinking density; GMOD−2, with moderate crosslinking density, remained intact under 85% compressive strain and achieved σₘ of 108.0 kPa. The degradation rate of GMODs was tunable by adjusting the crosslinking density, thereby modulating their drug-release behavior. GMOD−3, possessing the highest crosslinking density, exhibited effective drug-sustained release for up to five weeks. Biological evaluations, including cytotoxicity assays, live/dead cell staining, and hemolysis tests, verified excellent cytocompatibility (cell survival rate > 92%) and minimal hemolysis ratio (<5%). Furthermore, inhibition zone tests preliminarily revealed moderate antibacterial activity for GMOD−1. The GMOD hydrogels exhibited superior compressive robustness, adjustable biodegradability, and excellent biocompatibility, holding great potential for biomedical applications such as sustained drug-delivery system. Full article

Purple waxy corn cobs (PWCCs) represent an underutilized agricultural waste rich in anthocyanins with promising cosmeceutical potential. This study investigated niosome-based encapsulation to enhance the stability and bioactivity of PWCC anthocyanin extracts. PWCC extract was macerated in 50% ethanol. The extract exhibited a high total anthocyanin content (3.02 ± 0.81 mg C3GE/L), while cyanidin-3-glucoside identified as the major anthocyanin (1.17 ± 0.02 mg/g dry weight). Furthermore, the extracts showed strong antioxidant activities as evidence by DPPH, ABTS, and FRAP assays. The optimized niosome preparations synthesized by the probe sonication method exhibited better entrapment efficiency (80–85%), nanoscale particle size (185–296 nm), and stable zeta potential (−29 to −32 mV). TEM verification of the spherical morphology and FT-IR spectra confirmed the successful loading of anthocyanins. The thermal stability test exhibited negligible changes in the particle size and zeta potential. Furthermore, in vitro release profile followed the Higuchi model, indicating enhanced release kinetics. Biological assays demonstrated moderate UVB protection effects and potent anti-melanogenesis activity in B16F10 cells. Notably, formulation N5 exhibited the highest tyrosinase inhibition and melanin synthesis suppression. These findings indicate that niosome-based encapsulation represents a promising strategy for enhancing the stability, bioavailability, and biological efficacy of anthocyanin extracts, especially in the cosmetic and pharmaceutical industries. Full article

Natural deep eutectic solvents (NaDES) represent novel biodegradable green extraction solvents obtained from natural metabolites such as sugars and organic acids. NaDES-based extracts have demonstrated better performance in in vitro assays compared to those obtained using conventional solvents. In this study, extracts of bilberry leaves (BL), bilberry fruits (BF), and green tea leaves (TL) were prepared using the following NaDES, respectively—malic acid + glycerol (MG), citric acid + sorbitol (CS), and tartaric acid + sorbitol (TS), whose formation was confirmed via FTIR spectroscopy. With the aim to evaluate the effect of gels loaded with NaDES extracts on skin biophysical parameters 2 h prior their application, as well as their anti-irritation potential against sodium lauryl sulfate–induced irritation, an in vivo study involving human volunteers was conducted. The results indicated that all extract-loaded gels exhibited notable anti-irritation potential, reducing artificially induced irritation and improving elevated skin parameters including transepidermal water loss (TEWL), erythema index (EI), and pH. The ΔTEWL at CS–BF site was 8.20 ± 0.34, while at TS–TL was 5.63 ± 0.30. The short-term efficacy study revealed increased skin hydration across all treated sites, preservation of skin pH within physiological limits, and reduction in EI at the site treated with TS–TL gel. Further in vivo studies are planned for confirming long-term skin effects. Full article

Bio-based photo-crosslinkable hydrogels are used in tissue engineering as three-dimensional printable scaffolds due to their functional and biological similarities with the extracellular matrix (ECM). In this work, emerging bioink candidates such as chitosan, alginate and gelatin-based photo-crosslinkable hydrogel were developed using extrusion-based 3D printing to establish a better understanding of their applicability. The polymers were methacrylated by the same methacrylation reaction pathway, which enabled successful light-induced 3D printing. Morphology, swelling (6–40%), mechanical (Young’s modulus, 0.1–0.5 KPa) and rheological properties (300–1000 Pa), degradation kinetics (10->60 days) and printability of the gels were also characterized in identical conditions for the first time. 3D-printability results indicated that methacrylated gelatin enhanced printability, shape fidelity and integrity of printed structures compared to methacrylated alginate, which presents structural instability and poorer printing control due to its low crosslink density. Moreover, cell attachment and Live/Dead assays using bone marrow-derived mesenchymal stem cells (BM-MSCs) showed that all formulations have good biocompatibility for use as scaffolds. Specifically, gelatin-based hydrogels showed a higher level of BM-MSCs attachment and spreading than the other types of hydrogels. Overall, our results suggest that the hydrogels based on these three biopolymers present good potential as a biomaterial for light-induced extrusion-based 3D printing. Full article

Background and Objectives: The rapid increase of whitening products use raises questions about enamel safety. We compared three high-concentration protocols—Opalescence Quick (45% carbamide peroxide ≈ 15% H₂O₂), Opalescence Boost (40% H₂O₂), and BlancOne Ultra (35% H₂O₂ + LED)—under controlled conditions to balance color change (ΔE) with enamel integrity (microhardness, FTIR). We also constructed a qualitative cytotoxicity risk profile from published data; no biological assays were performed in this study. Methods: Seventy-two matched half-crowns were randomized to Control or one of the three protocols. Outcomes were a change in Vickers microhardness, spectrophotometric color difference, and FTIR carbonate-to-phosphate ratio after 24 h in artificial saliva. We also compiled a qualitative cytotoxicity risk profile from published evidence; no biological assays were performed. One-way ANOVA with Tukey HSD on Δ-scores, Shapiro–Wilk and Levene’s tests for assumptions, Welch’s t-tests for tooth-class comparisons, and Pearson correlation between ΔE and ΔMH. Results: All active protocols produced clearly visible whitening (mean ΔE 5.7–6.3). Hydrogen-peroxide gels showed greater hardness loss and carbonate depletion than the carbamide-peroxide gel under similar contact time. The association between greater shade change and hardness loss was moderate and not predictive for individuals. Conclusions: Under harmonized conditions, all systems whitened effectively. Pursuing changes beyond ~6 units offered little extra benefit while increasing enamel impact. Carbamide-based Opalescence Quick achieved comparable aesthetics with lower acute enamel effects. Clinicians should individualize exposure time and pair in-office whitening with short-term remineralising care. Cytotoxicity comments are qualitative and literature-based only. Full article

Background: Skin infections caused by Staphylococcus aureus represent a major public health concern, and plant extracts, such as those from Cochlospermum regium, have emerged as promising therapeutic alternatives. Methods: This study developed carbopol-based gel formulations containing ethanolic leaf extracts of C. regium (CRG 0.5% and 1%) and evaluated their physicochemical stability, antibacterial activity against S. aureus and a methicillin-resistant wound isolate, antioxidant potential, and biocompatibility. Results: Both CRG 0.5% and 1% were physically stable and maintained antibacterial activity for up to 90 days at 8 °C, while at 25 °C only CRG 1% retained activity throughout the evaluation period. In ex vivo pig skin assays, CRG 1% reduced methicillin-resistant S. aureus contamination by 99%, outperforming the conventional topical antibacterial agent (neomycin + bacitracin), which achieved 66% inhibition. The extract also exhibited high antioxidant activity without mutagenic or hemolytic effects. Although phenolic and flavonoid contents decreased over time, CRG 1% preserved adequate levels for therapeutic application. Conclusions: These findings indicate that CRG 1% has potential as a stable, safe, and effective alternative for the treatment of topical infections, particularly those caused by methicillin-resistant S. aureus. Full article

This study aimed to develop an optimized film-forming gel for topical anti-acne applications by evaluating the antibacterial efficacy of propolis, honey, and royal jelly, individually and in combination with low-dose salicylic acid. The antibacterial activities were assessed against Staphylococcus aureus, Staphylococcus epidermidis, and Cutibacterium acnes using the inhibition zone assay. Film-forming gels were developed by evaluating the effects of type and concentration of polymers and plasticizers. Each formulation was evaluated for visual appearance, pH, viscosity, and drying time, along with the appearance of the corresponding film. The findings noted that propolis (1% w/w) exhibited the strongest antibacterial activity among individual bee products, producing an inhibition zone of 20.0 ± 1.0 mm against S. aureus. The combination of bee products with low-dose salicylic acid (0.1% w/w) markedly enhanced antibacterial efficacy, particularly against C. acnes (inhibition zone 40.8 ± 0.8 mm). Incorporation of this combination into the optimized film-forming gel, containing polyvinyl alcohol, Carbomer^® 940, polyethylene glycol 400, glycerin, and water, produced a formulation with balanced pH, suitable viscosity, 31 min drying time, and complete inhibition of S. aureus and S. epidermidis. Therefore, bee product-based film-forming gels, combined with low-dose salicylic acid, exhibited favorable physicochemical properties and showed promise as complementary anti-acne therapies. Full article

This study explores an innovative delivery strategy for the management of skin conditions: lipid nanosystems incorporated into a gel matrix. Echinacea purpurea extract, known for its antibacterial, antioxidant, and wound-healing properties, was encapsulated into lipid-based nanosystems and subsequently incorporated into Carbopol-based gel. The extract, rich in chicoric and caftaric acids, exhibited strong antioxidant activity (IC₅₀ = 56.9 µg/mL). The resulting nanosystems showed nanometric size (about 200 nm), high entrapment efficiency (63.10–75.15%), and excellent short-term stability. Superior biocompatibility of the nanosystems, compared to the free extract, was demonstrated using an MTS assay on L-929 fibroblasts. Moreover, the cytoprotective potential of the lipid carriers was evident, as pre-treatment significantly increased cell viability under H₂O₂-induced oxidative stress. These findings suggest that lipid-based encapsulation enhances the therapeutic profile of E. purpurea. The optimal lipid formulation was incorporated into a Carbopol-based gel, which demonstrated an appropriate pH (5.15 ± 0.75), favorable textural properties, sustained polyphenol release, and overall good stability. This research highlights the potential of plant-derived bioactives in the development of dermatocosmetic products, aligning with current trends in eco-conscious and sustainable skincare. Full article

Head and neck cancer (HNC) is highly heterogeneous and difficult to treat, underscoring the need for rapid, patient-specific models. Standard three-dimensional (3D) cultures often lose stromal partners that influence therapy response. We developed a patient-derived system maintaining tumor cells, cancer-associated fibroblasts (CAFs), and cells undergoing partial epithelial–mesenchymal transition (pEMT) for drug sensitivity testing. Biopsies from four HNC patients were enzymatically dissociated. CAFs were directly cultured, and their conditioned medium (CAF-CM) was collected. Cryopreserved primary tumor cell suspensions were later revived, screened in five different growth media under 2D conditions, and the most heterogeneous cultures were re-embedded in 3D hydrogels with varied gel mixtures, media, and seeding geometries. Tumoroid morphology was quantified using a perimeter-based complexity index. Viability after treatment with cisplatin or Notch modulators (RIN-1, recombination signal-binding protein for immunoglobulin κ J region (RBPJ) inhibitor; FLI-06, inhibitor) was assessed by live imaging and the water-soluble tetrazolium-8 (WST-8) assay. Endothelial Cell Growth Medium 2 (ECM-2) medium alone produced compact CAF-free spheroids, whereas ECM-2 supplemented with CAF-CM generated invasive aggregates that deposited endogenous matrix. Matrigel with this medium and single-point seeding gave the highest complexity scores. Two of the three patient tumoroids were cisplatin-sensitive, and all showed significant growth inhibition with the FLI-06 Notch inhibitor, while the RBPJ inhibitor RIN-1 induced minimal change. The optimized scaffold retains tumor–stroma crosstalk and provides patient-specific drug response data within days after operation, supporting personalized treatment selection in HNC. Full article

The use of antioxidants in the dermatocosmetic industry has become increasingly popular to help protect and stabilize other sensitive active ingredients, prolonging the effectiveness and durability of the cosmetic product. Grape pomace, as the main by-product generated through winemaking, and Polygonum cuspidatum, concentrate bioactive metabolites with high antioxidant activity. Hydroalcoholic extracts obtained from grape pomace (Merlot and Feteasca Neagra varieties) and the root and flower of Japanese knotweed, respectively, alone and in mixtures, were characterized, and preliminary assays were conducted for their incorporation in two gel-based cosmetic formulations. The characterization of the extracts revealed the presence of catechin, vanillic acid, caffeic acid, myricetin, resveratrol, and kaempferol. The hydroalcoholic extract of P. cuspidatum flower and root was found to have the highest content of total phenolic compounds (10.920 ± 0.268 mg GAE/mL, respectively, 4.751 ± 0.072 mg GAE/mL), and the highest antioxidant activity (expressed as DPPH Radical Scavenging Capacity, IC₅₀) by 28.04 ± 1.12 µg GAE/mL and 83.91 ± 1.13 µg GAE/mL, respectively. Catechin was the most abundant polyphenol found in pomace extract (687.87 mg/kg). The type and the concentration of the plant extract used in dermatocosmetic gel formulations influenced their antioxidant activity. Encapsulation of P. cuspidatum flower extract in liposomes prior to their incorporation into the gel formulation demonstrated the role of liposomes in enhancing the stability and modulation of phenolic compound delivery. It is worth noting that this dermatocosmetic formulation, which contains the flower extract of P. cuspidatum, was the subject of a pending patent application. Full article

The popularity of processed meats stems from modern demand for ready-to-eat foods, but their saturated and trans fats pose health concerns. Oleogel-based systems, which turn healthy oils into solid fat-like matrices, offer a promising alternative. This study characterized virgin olive oil oleogels structured with chitosan, assessing rheological, thermal, structural, and functional properties, examining how chitosan concentration (1–3%) and oil-to-water ratio (50–60) affect their performance. Rheological tests indicated a predominantly elastic behavior, suggesting the formation of stable gel networks, while a thermogravimetric analysis confirmed thermal stability of up to 237 °C, indicating suitability for moderate thermal processing. Texture analysis showed wider values for hardness (1.25–12.20 N) and color measurements indicated a homogeneous appearance across formulations with oleogels with high luminosity (L* > 50). The oleogels demonstrated high oil-binding capacity (>90%) and reduced oxidative degradation compared to bulk olive oil (peroxide values within regulatory limits for olive oils and TBARS values below 0.6 μmol malonaldehyde). In vitro digestion assays showed a slightly reduced lipid release with respect to pure olive oil, highlighting their potential for controlled lipid delivery and enhanced nutritional value. These findings support the potential of chitosan-based oleogels with virgin olive oil as stable and functional fat replacers in food applications. Full article

Traditional chemical-based sanitizers pose risks to health and the environment, highlighting the need for safer natural alternatives. We developed biocompatible hydrogels from carbohydrate-based biopolymers, chitosan (1.5% and 2.5%), and carboxymethylcellulose (CMC, 3% and 5%), each incorporating one of four antimicrobials: microcin J25, nisin Z, pediocin PA-1, or reuterin. Hydrogels were prepared by dissolving the polymers in aqueous solution and incorporating antimicrobials before gelation. The formulations were characterized using viscosity measurements, antimicrobial assays, and stability testing over 28 days of storage at room temperature (23–25 °C). Chitosan hydrogels with microcin J25 maintained strong activity against Salmonella enterica ATCC 6962, while nisin Z retained activity in gel and solution forms, though with some decline during storage. Pediocin PA-1 remained active in 1.5% and 2.5% chitosan hydrogels against Listeria monocytogenes ATCC 19115, but activity was lost in 3% and 5% CMC hydrogels. Reuterin preserved activity in CMC-based hydrogels throughout storage. In solution, microcin J25 and nisin Z consistently achieved ~7-log reductions, whereas pediocin PA-1 and reuterin reached up to ~5-log reductions. In gels, efficacy decreased at lower concentrations and shorter contact times, likely due to diffusion barriers. Overall, the hydrogels remained stable during storage, and CMC- and chitosan-based matrices with selected antimicrobials show promise as alternatives to chemical sanitizers. Their application should be tailored to specific needs, with formulations requiring longer contact times best suited for surfaces that allow prolonged exposure. Full article