Search Results (51)

The threat of antimicrobial resistance (AMR) and the need for sustainable disinfectants have spurred interest in natural antimicrobials such as essential oils (EOs). However, their application is limited by volatility, poor water solubility, and cytotoxicity. Herein, we present the development of bio-based core–shell sub-micro-/nanocapsules (NCs) with encapsulated oregano (OO), thyme (TO), eucalyptus (EuO), and tea tree (TTO) oils to enhance antimicrobial (AM) performance and reduce cytotoxicity. NCs were synthesized via a nanoencapsulation method using chemically modified zein or poly(methyl vinyl ether-co-maleic anhydride) (GZA) as shell polymers, with selected EOs encapsulated in their core (encapsulation efficacy > 98%). Chemical modification of zein with vanillin (VA) and GZA with either dodecyl amine (DDA) or 3-(glycidyloxypropyl)trimethoxysilane (EPTMS) resulted in improvement in particle size distributions, polydispersity indices (PDIs) of synthesized NCs, and in the stability of the NC-dispersions in water. Antibacterial testing against Staphylococcus aureus and cytotoxicity assays showed that encapsulation significantly reduced toxicity while preserving their antibacterial activity. Among the formulations, GZA-based NCs modified with EPTMS provided the best balance between safety and efficacy. Despite this, life cycle assessment revealed that zein-based NCs were more environmentally sustainable due to lower energy use and material impact. Overall, the approach offers a promising strategy for developing sustainable, effective, and safe EO-based antibacterial agents for AM applications. Full article

The use of natural bioactive compounds in edible coatings provides a sustainable approach to reducing food spoilage and meeting consumer demand for safer food preservation. In this study, bioactive extracts from Brassica juncea (green mustard, GM) and Raphanus sativus (radish tango, RT) sprouts were encapsulated into zein/chitosan (Z/CH) microparticles (MPs) using a complex coacervation–based encapsulation approach. The encapsulated microparticles (MPs), characterized by FTIR and UV-Vis spectroscopy, demonstrated a high loading efficiency of up to 90% and maintained their antioxidant activity for up to 168 h. TGA and SEM tests confirmed that the edible films produced by incorporating these microparticles (MPs) into polyvinyl alcohol (PVA) and chitosan (CH) matrices had a more uniform microstructure and enhanced heat stability. The Z/CH/RT6:PVA (1:2) and Z/CH/GM6:CH (1:1) formulations of the films showed significant antioxidant and antibacterial action, with up to 22.4% DPPH inhibition and a 1-log decrease in Salmonella enterica CFU, respectively. Overall, the results underscore the promise of sprout-derived microparticles as components for developing active, biodegradable packaging films with improved functional properties. Full article

Surfactants are commonly employed in cleaning, cosmetic, and pharmaceutical formulations due to their ability to lower surface tension and facilitate the formation of emulsions, foams, and dispersions. Recent research highlights the advantages of synergistic interactions between anionic and nonionic surfactants to improve overall performance. In this study, the physicochemical properties and performance of binary mixtures of the anionic surfactant sodium lauryl sulfate (SLS) and the amphoteric surfactant lauryl dimethyl amine oxide (LDAO) at varying ratios (100% SLS, 90:10, 80:20, 70:30, 60:40, and 50:50) were investigated. Key parameters analysed included critical micelle concentration (CMC), surface tension (γ), foam volume, and potential irritability, assessed via the Zein test. The results revealed a clear synergistic effect between SLS and LDAO: all mixtures showed reduced CMC and minimum surface tension compared to the individual surfactants, while exhibiting enhanced foam volume and stability. Regarding irritability, increasing LDAO content consistently led to decreased protein denaturation, indicating lower irritancy levels. Furthermore, the results obtained in the Zein test confirmed that mixtures induced less protein denaturation than the sum of their individual surfactant components, with formulations ranging from moderately to non-irritating. The results obtained indicate that the more stable mixed micelle systems (SLS + LDAO) might improve the performance of cleaning formulations (γ, CMC, foam) while reducing the irritability. Full article

Background/Objectives: PEGylated zein nanoparticles (PZNs) loaded with losartan potassium (LOS) were developed as a repurposed treatment for vaginal methicillin-resistant Staphylococcus aureus (MRSA) infection. PZNs were prepared using the ethanol injection method with different types and amounts of Brij^® surfactant. Methods: The prepared formulations were optimized using a D-optimal mixture design via Design-Expert^® software version 13. The assessed responses included entrapment efficiency (EE%), particle size (PS), and zeta potential (ZP). Results: The optimized PZNs, composed of 30 mg Brij^® O20 and 10 mg zein, exhibited spherical particles with an EE% of 90.58 ± 1.20%, PS of 200.81 ± 1.39 nm, PDI of 0.395 ± 0.01, and ZP of −36.59 ± 0.05 mV. Confocal laser scanning microscopy confirmed complete deposition of fluorescein-labeled PZNs within vaginal tissues. Ex vivo studies showed that PZNs resulted in prolonged permeation of LOS compared to the LOS solution. In a murine model of MRSA infection, the optimized PZNs demonstrated superior therapeutic efficacy over the LOS solution. Histopathological examinations confirmed the safety of the tested formulations. Conclusions: In conclusion, the optimized PZNs present a promising approach for the treatment of MRSA-related vaginal infections. Full article

Background/Objectives: The study developed, characterized, and evaluated the toxicity, antibacterial and antibiofilm activity of quercetin encapsulated in chitosan-coated zein nanoparticles (QUER-ZNP-CH). Methods: QUER-ZNP-CH were prepared by the nanoprecipitation method and characterized by physicochemical analyses, stability (12 months), and release kinetics. Toxicity was evaluated through hemocompatibility and a Tenebrio molitor larval model. Antibacterial activity (MIC/MBC, CLSI) and antibiofilm potential (crystal violet assay) were tested against resistant Klebsiella pneumoniae strains. Results: The nanoparticles were prepared, and physicochemical analyses revealed chemical interactions, efficient encapsulation of the drug, and thermal stability. The formulations remained stable over 12 months, and the release kinetics demonstrated controlled release for 72 h. No hemotoxic profile was observed and there was 95% survival of Tenebrio molitor larvae after treatment with QUER-ZNP-CH. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of QUER-ZNP-CH revealed enhanced antibacterial activity of QUER, as indicated by a 32 to 64-fold reduction in the MIC and MBC values. The biofilm inhibition potential of QUER-ZNP-CH showed 60–100% inhibition and 25–95% eradication in concentrations from 0.12 to 62.5 μg/mL. Conclusions: Thus, this nanotechnology-based formulation suggests potential for the treatment of bacterial infections caused by multidrug-resistant K. pneumoniae strains. Full article

This study investigated gelatin/zein nanofibers loaded with dihydromyricetin (0–20%, relative to protein weight), before and after the Maillard reaction (60 °C with 50% relative humidity for 6 h). Scanning electron microscopy and diameter distribution analysis indicated that dihydromyricetin incorporation increased the fiber diameter from 692 ± 133 to 922 ± 121 nm, while the nanofibers maintained a uniform morphology following the Maillard reaction. Fourier transform infrared spectroscopy revealed that dihydromyricetin formed hydrogen bonds with protein molecules. X-ray diffraction results indicate that dihydromyricetin was uniformly dispersed within the gelatin/zein nanofibers. The addition of dihydromyricetin improved the thermal stability of the nanofibers. Furthermore, after the Maillard reaction, the nanofibers with dihydromyricetin demonstrated enhanced water resistance. Mechanical testing revealed that nanofibers containing 20% dihydromyricetin after the Maillard reaction exhibited a considerably higher elastic modulus of approximately 90 MPa. In addition, nanofibers containing dihydromyricetin exhibited notable antioxidant activity and antibacterial properties against Escherichia coli and Staphylococcus aureus. In summary, gelatin/zein nanofibers containing high concentrations of dihydromyricetin exhibited favorable physical and functional properties, supporting their suitability as effective delivery systems for dihydromyricetin in active packaging applications. Full article

Microalgae are a rich renewable source of a wide variety of bioactive compounds. This study focuses on seven microalgae—Limnospira sp., Dunaliella sp., Lobosphaera sp., Nannochloropsis sp., Odontella sp., Porphyridium sp., and Tetraselmis sp.— analyzing their nutritional compositions and the potential bioactivity of their hydroethanolic extracts obtained via ultrasound-assisted extraction. The total phenolic content (TPC) and antioxidant activity (ABTS, DPPH, and ORAC), as well as the antimicrobial activity of the extracts were determined. The protein content of the microalgae ranged from 22.9 ± 0.1 to 59.8 ± 1.6%, the fat content ranged from 5.3 ± 0.0 to 36.6 ± 0.0%, and the carbohydrates ranged from 24.0 ± 3.0 to 46.1 ± 1.0%. The highest contents of protein, fat, and carbohydrates were found in Limnospira sp., Nannochloropsis sp., and Lobosphaera sp., respectively. The TPC of the extracts varied between 0.53 ± 0.09 and 3.18 ± 0.53 mg GAE/100 mg DW. Antioxidant activity values ranged from 1.09 ± 0.15 and 2.85 ± 0.45 μmol TE/100 mg DW for ABTS, 0.25 ± 0.06 and 2.28 ± 0.06 μmol TE/100 mg DW for DPPH, and 2.37 ± 0.58 and 18.32 ± 1.00 μmol TE/100 mg DW for ORAC. The extract from Limnospira sp. exhibited the highest antioxidant activity and also showed notable antimicrobial effects. Meanwhile, the Nannochloropsis sp. extract demonstrated the strongest antimicrobial activity against most tested bacterial strains. Lipids were successfully extracted from Nannochloropsis sp. Furthermore, alginate and zein films incorporated with bioactive-rich extracts from Limnospira sp. and Nannochloropsis sp., along with the lipid-rich extract from Nannochloropsis sp., were developed. These films showed significant antioxidant activity and effective antimicrobial activity against Listeria monocytogenes. Full article

Vitamin E is widely used in cosmetics and dermatological applications for its antioxidant, anti-inflammatory, and healing properties, yet its industrial use is limited by poor stability and bioavailability. To address these challenges, this study developed zein-based microstructures encapsulating vitamin E using electrohydrodynamic (EHD) techniques and evaluated how zein concentration affects morphology and release behavior. The SEM analysis showed that biopolymer (zein) concentration significantly affects microstructure morphology. At low concentrations (1%, 5%, and 15% (w/v)), micro/nanoparticles are formed, and high concentrations (30% (w/v)) yielded only fibers. The average size of the structures produced with zein (1–15% w/v) ranged from 0.38 to 0.90 µm, as measured using the program ImageJ (v1.54d). Structures containing vitamin E were generally smaller than those without. For electrospun fibers made with 30% zein, diameters ranged from 0.49 to 0.74 µm, with vitamin E-containing fibers also being thinner. Conductivity also influenced morphology; higher conductivity developed fibers, while lower conductivity formed particles. The solution with 15% (w/v) zein + 1% (w/w) vitamin E showed a conductivity of 1276 μS, similar to the 15% zein solution (1280 μS), indicating that vitamin E addition had no significant effect on conductivity. Release assays revealed that structures produced with low zein concentrations led to immediate release, while structured made with higher concentrations, prolonged release. A preliminary cosmetic formulation test has been conducted. The vitamin E microstructures were successfully incorporated into aloe vera hydrogel and coconut oil to show their potential for cosmetic applications. Full article

Flexible, biocompatible, and adhesive materials are vital for wearable strain sensors in bioelectronics. This study presents zein-polyaniline (ZPANI) hydrogels with mechanoresponsive energy-harvesting properties. SEM revealed a sheet-like fibrous morphology, enhancing adhesion. Incorporating 0.5 wt% polyaniline (PANI) introduced nanostructured aggregates, while higher PANI concentrations (3–5 wt%) formed intertwined fibrous networks, improving the mechanical integrity, surface area, and conductivity. PANI enhanced electrical conductivity, and the hydrogels displayed excellent swelling behavior, ensuring flexibility and strong tissue adhesion. Biocompatibility was validated through fibroblast cell culture assays, and the adhesive properties were tested on substrates, such as porcine skin, steel, and aluminum, demonstrating versatile adhesion. The adhesion strength of hydrogels to porcine skin was greatly enhanced with an increasing amount of PANI. The maximum adhesion strength was found to be 30.1 ± 2.1 kPa for ZPANI-5.0. Mechanical testing showed a trade-off between strength and conductivity. The tensile strength decreased from 13.4 kPa (ZPANI-0) to 7.1 kPa (ZPANI-5.0), and the compressive strength declined from 18.5 kPa to 1.6 kPa, indicating increased brittleness. A rheological analysis revealed enhanced strain tolerance (>500% strain) with an increasing PANI content. The storage modulus (G′) remained stable up to 100% strain in PANI-free hydrogels but collapsed beyond 450% strain, while PANI-containing hydrogels exhibited improved viscoelasticity. Mechanical testing showed robust voltage output signals under compression within a 20 s response time. Despite the reduced mechanical strength, energy-harvesting tests showed a surface power density of 0.12 nW cm⁻², charge storage of 0.71 nJ, and a surface energy density of 1.4 pWh cm⁻². The synergy of the piezoelectric response, bioadhesion, and tunable viscoelasticity establishes ZPANI hydrogels as promising candidates for wearable sensors and energy-harvesting applications. Optimizing the PANI content is crucial for balancing mechanical stability, adhesion, and electrical performance, ensuring long-term bioelectronic functionality. Full article

A novel series of biocomposites was prepared through the utilisation of hot-pressing and blending methods, utilising bamboo particles of varying sizes and a zein solution. The influence of particle size and the parameters of hot pressing on the mechanical properties of the composites was investigated through the application of an alkali solution to pre-treat the bamboo particles and the employment of ultra-high pressure to pre-handle the zein solution. Four response surface models were established to optimise the processing parameters based on mechanical testing experiments and quadratic regression analysis. The influencing factors were moisture content, press temperature, and press time, and the responses were modulus of rupture (MOR), modulus of elasticity (MOE), tensile strength (TS) and 2 h thickness swelling rate (2h-TSR). The findings indicated that the TS of composites reached a maximum value of 17.5 MPa with a bamboo particle size of 40 mesh; the MOR and MOE of composites reached a maximum value of 28.72 MPa and 2669.75 MPa when the bamboo particle size was 60 mesh; regarding the 2h-TSR of composites the lowest value of 5.8% was obtained for 80-mesh bamboo particle size. The optimum moulding process parameters were obtained with moisture content ranging from 14% to 16%, press temperature ranging from 170 °C to 175 °C, and press time ranging from 12 min to 15 min, respectively. Full article

Zein was made flexible through acid-driven deamidation. This increased flexibility was confirmed by the higher release of water-soluble peptides during trypsin hydrolysis. Self-assembled flexible zein nanoparticles (FZNPs) were prepared using the anti-solvent precipitation method. To test the sensitivity of FZNPs to complex environment, ionic solutions (CaCl₂ and NaCl) at various concentrations were prepared. The morphology and particle size of FZNPs differed significantly from those of control zein nanoparticles (NZNPs). As the ionic concentration increased from 0 to 15 mmol/L, FZNPs showed higher electrical conductivity and adsorption capacity than NZNPs. This suggests that FZNPs are highly sensitive to complex environment. X-Ray Photoelectron Spectrum (XPS) results revealed that both FZNPs and NZNPs bound more Na⁺ than Ca²⁺. The enhanced sensitivity of FZNPs to complex environments may be due to their greater tendency for structural changes. These conformational changes are likely caused by the altered amino acids in flexible zein, which result from deamidation. This study offers a practical approach to designing novel nanoparticles as functional materials for delivering bioactive compounds. Full article

Background/Objectives: Nanovaccines have significant potential to enhance immunization strategies by improving efficacy, safety, and cost-effectiveness. In particular, organic nanoparticles hold promise for the generation of low-cost nanovaccines obtained by environmentally friendly methods. In this study, the feasibility of using zein nanoparticles (NPs) as carriers for an antigenic peptide (p30) and the receptor binding domain (RBD) from SARS-CoV-2 spike protein was explored. Methods: A synthesis method for zein NPs was established by combining previously reported techniques, and the resulting NPs were characterized in terms of morphology, particle size, polydispersity index (PDI), surface charge, and colloidal stability using dynamic light scattering (DLS) and transmission electron microscopy (TEM). Tween 20 was employed as a surfactant to enhance particle stability and prevent aggregation. Results: The zein NPs were deemed safe based on an in vitro cytotoxicity assay using Vero cells. Immunogenicity assessments demonstrated that zein NPs:p30 and zein NPs:RBD induced IgG responses in test mice, whose magnitude was comparable to those achieved with alum as an adjuvant. Conclusions: These findings support the use of zein NPs as promising vaccine delivery vehicles with adjuvant effects due to their ease and environmentally friendly synthesis, high stability, and low cost. Full article

Background/Objectives: Leishmaniasis, caused by protozoa of the genus Leishmania, is a major global health issue due to the limitations of current treatments, which include low efficacy, high costs, and severe side effects. This study aimed to develop a more effective and less toxic therapy by utilizing zein nanoparticles (ZNPs) in combination with a nonpolar fraction (DCMF) from Fridericia platyphylla (Syn. Arrabidaea brachypoda), a plant rich in dimeric flavonoids called brachydins. Methods: Zein nanoparticles were used as carriers to encapsulate DCMF. The system was characterized by measuring particle diameter, polydispersity index, zeta potential, and encapsulation efficiency. Analytical techniques such as FTIR, DSC, and AFM were employed to confirm the encapsulation and stability of DCMF. Antileishmanial activity was assessed against Leishmania amazonensis promastigotes and amastigotes, while cytotoxicity was tested on RAW264.7 macrophages. Results: The ZNP-DCMF system exhibited favorable properties, including a particle diameter of 141 nm, a polydispersity index below 0.2, and a zeta potential of 11.3 mV. DCMF was encapsulated with an efficiency of 94.6% and remained stable for 49 days. In antileishmanial assays, ZNP-DCMF inhibited the viability of promastigotes with an IC50 of 36.33 μg/mL and amastigotes with an IC50 of 0.72 μg/mL, demonstrating higher selectivity (SI = 694.44) compared to DCMF alone (SI = 43.11). ZNP-DCMF was non-cytotoxic to RAW264.7 macrophages, with a CC50 > 500 μg/mL. Conclusions: Combining F. platyphylla DCMF with zein nanoparticles as a carrier presents a promising approach for leishmaniasis treatment, offering improved efficacy, reduced toxicity, and protection of bioactive compounds from degradation. Full article

Background/Objectives: Cationic surfactants are potential antimicrobial candidates. Even so, they are the foremost irritative and incompatible group, which limits their usage. The incorporation of surfactants in biopolymer-based nanoparticles is a feasible strategy to improve their efficacy and reduce those drawbacks. Methods: Surfactants with one amino acid on the polar head (lauroyl arginine methyl ester—LAM and phenylalanine dodecyl amide—PNHC₁₂) and surfactants with two amino acids on the polar heads, arginine-phenylalanine (Lauroyl phenylalanine arginine methyl esther—C₁₂PAM and phenylalanine-arginine dodecyl amide—PANHC₁₂) were loaded to zein nanoparticles. Their antimicrobial and antibiofilm activities were evaluated. Also, the inhibitory activities of the surfactants and nanoparticles over skin-related enzymes were accessed in silico and in vitro, while their cytotoxicity was determined comparatively over immortal human keratinocytes (HaCaT) and human fibroblasts (3T3). Finally, the Vibrio fisheri luminescence reduction test was used to detect its ecotoxicity. Results: The nanoparticles were obtained successfully and exhibited good biocide activity against a wide range of pathogenic bacteria and yeasts. The surfactants were found active over the enzymes assayed: elastase > tyrosinase > collagenase > lipoxygenase, while the inhibitory activity was superior when nanoencapsulated over the enzymes tyrosinase and lipoxygenase. The surfactants and their corresponding nanoparticles presented acceptable cytotoxic levels, except for PNHC₁₂ in both forms, while their ecotoxicity was limited and acceptable. Conclusions: Accordingly, the nanoencapsulation of the arginine-phenylalanine surfactants loaded to zein nanoparticles was found to be a smart strategy to enhance the antimicrobial activity and improve their selectivity over representative skin and connective tissues cell lines. These biological properties render the arginine-phenylalanine surfactant nanoparticles as promising candidates for antimicrobial and tissue repairing applications in wound treatments. Full article

The objective of this study was to prepare zein–gum Arabic nanocapsules with rosehip oil (NC-RH), apply them to pork tenderloin, and analyze the changes in collagen structure under different conditions (pH 6.5 and 4.0) and temperatures (25 °C and 4 °C). NC-RHs were prepared using the nanoprecipitation method. Nanocapsules had a particle size of 423 ± 4.1 nm, a polydispersity index of 0.125 ± 3.1, a zeta potential value of −20.1 ± 0.41 mV, an encapsulation efficiency of 75.84 ± 3.1%, and backscattering (ΔBS = 10%); the antioxidant capacity of DPPH was 1052 ± 4.2 µM Eq Trolox and the radical scavenging capacity was 84 ± 0.4%. The dispersions exhibited Newtonian behavior at 25 °C and 4 °C. Incorporating NC-RH into acid marination benefited the tenderness, water-holding capacity, and collagen swelling, and favored changes in myofibrillar proteins corroborated with histological tests. The conditions with the best changes in pork tenderloin were a pH of 4.0 at 4 °C with an NC-RH-administered 11.47 ± 2.2% collagen area. Incorporating rosehip nanocapsules modifies collagen fibers and can be applied in pork marinades to increase the shelf life of a functional product. Full article