Carvacrol Loaded Solid Lipid Nanoparticles of Propylene Glycol Monopalmitate and Glyceryl Monostearate: Preparation, Characterization, and Synergistic Antimicrobial Activity

Monitoring the Interaction Between Solid Lipid Nanoparticles and Alveolar Macrophages Via the Label-Free Technique

Macrophages are employed as targets for delivering genes, drugs, or lipid nanoparticles into tumors or other specific sites. Studying the interaction between solid lipid nanoparticles (SLNs) and macrophages is essential for assessing nanotoxicity and advancing the development of nanomedicines. However, limited data are currently available on the membrane microstructure and biochemical changes that occur when macrophages interact with SLNs. We conducted a label-free morphological and biochemical investigation of NR8383 macrophages using optical diffraction tomography (ODT), which validated the efficiency of the SLNs as a drug delivery system. ODT provided intracellular holotomography to characterize the macrophages and fluorescence imaging to analyze delivery efficiency. ODT analysis revealed the responses of phagocytic macrophages. Additionally, a quantitative analysis of lipid droplets using refractive indices revealed that, compared with incubation with normal cells, incubation with SLNs significantly increased the lipid droplet volume and surface area. The uptake of SLNs into macrophages resulted in increased cell volume, surface area, and concentration, which indicated greater morphological and biochemical variability in the treated cells than in the control cells. The results suggest that ODT imaging is promising for understanding the intracellular distribution of SLNs and useful for validating the efficacy of delivery of SLNs to macrophages.

Effect of alginate coating activated by solid lipid nanoparticles containing Zataria multiflora essential oil on chicken fillet's preservation

The current study aimed to assess the chemical, microbial, and sensory properties of Solid Lipid Nanoparticles (SLNs) in chicken fillets stored at 4 ± 1 °C for 12 days. As a result, the optimized ZEO-SLNS sample exhibited a spherical morphology with a droplet size of 251.51 ± 1.11 nm and a PDI of 0.34 ± 0.01 under transmission electron microscopy (TEM). The encapsulation efficiency (EE) and zeta potential were approximately 55.4 % and -20.87 ± 1.39 mV, respectively. Furthermore, encapsulating ZEO in SLNS enhanced antibacterial and antioxidant activity compared to pure ZEO. As a result, the application of alginate-loaded ZEO-SLNS extended the storage time of fresh chicken fillets. Thus, the application of this edible coating showcased a remarkable ability to substantially decelerate both microbial and chemical changes in chicken fillets during cold storage conditions. This finding underscores the potential of the edible coating as an effective means to enhance the safety and quality of chicken products.

Effect of cinnamaldehyde-nanoemulsion and nanostructured lipid carriers on physicochemical attributes of reduced-nitrite sausages

This study aimed to produce cinnamaldehyde (CA)-loaded nanostructured lipid carriers (NLC) and nanoemulsion (NE) to replace nitrite in sausage. The NLC and NE droplet sizes were 132 and 116 nm with encapsulation efficiency of 98 and 96 %, respectively. In in vitro antimicrobial assessment, the free CA and NE showed higher microbial activity against S. aureus and E. coli than NLC. Meanwhile, NE showed a faster release profile for CA than NLC. Among the samples, NE and NE + nitrite indicated the lowest peroxide value (3.7 ± 0.1), TVBN amount (8.6 ± 0.2), acidity (0.3 ± 0.02), microbial quality (against E. coli, C. perfringens, lactic acid bacteria, psychrophilic bacteria, total mold and yeast, and total viable counts), and sensory attribute, while the NE + nitrite sample exhibited better color properties and higher oxymyoglobin content (5-10 % higher). Therefore, NE + nitrite can be the best choice due to supporting the different quality parameters of sausage.

Formulation and Characterization of Intranasal Drug Delivery of Frovatriptan-Loaded Binary Ethosomes Gel for Brain Targeting

Background

Frovatriptan succinate (FVT) is an effective medication used to treat migraines; however, available oral formulations suffer from low permeability; accordingly, several formulations of FVT were prepared.

Objective

Prepare, optimize, and evaluate FVT-BE formulation to develop enhanced intranasal binary nano-ethosome gel.‎.

Methods

Binary ethosomes were prepared using different concentrations of phospholipid PLH90, ethanol, propylene glycol, and cholesterol by thin film hydration and characterized by particle size, zeta potential, and entrapment efficiency. Furthermore, in-vitro, in-vivo, ex-vivo, pharmacokinetics, and histopathological studies were done.

Results

Regarding FVT-loaded BE, formula (F9) demonstrated the best parameters from the other formulas; with the lowest particle size (154.1±4.38‎ nm), lowest PDI (‎0.213±0.05), highest zeta potential (‎-46.94±1.05), and highest entrapment efficiency (89.34±2.37%). Regarding gel formulation, G2 showed the best gel formula with drug content (‎99.82±0.02‎%) and spreadability (12.88 g/cm2). In-vitro study results showed that, in the first 30 minutes, around 22.3% of the medication is released, whereas, after 24 hours, about 98.56% is released in G2.

Conclusion

Based on enhancing the bioavailability and sustaining the drug release, it can be concluded that the Frovatriptan-Loaded Binary ethosome Gel as nano-delivery was developed as a promising non-invasive drug delivery system for treating migraine.

Effect of nanocomposite alginate-based edible coatings containing thymol-nanoemulsion and/or thymol-loaded nanostructured lipid carriers on the microbial and physicochemical properties of carrot

In this study, the effect of thymol-nanoemulsion (NE) and thymol-loaded nanostructured lipid carriers (NLC) on the physiological and microbial quality of carrot was investigated. The NE and NLC droplet sizes were 86 and 140 nm with encapsulation efficiency of 97 and 94 %, respectively. The minimum inhibitory concentration and minimum bactericidal concentration of thymol decreased in NE and increased in NLC against E. coli and S. aureus. Moreover, thymol-containing coatings exhibited a higher peroxidase activity, total phenolic content, flavonoid content, DPPH radical scavenging activity, pH, and lower respiration rate, TSS, weight loss, and decay with the preference for samples coated with NLC and NE (particularly NLC). The NE and NLC treatments significantly reduced the total viable, mold and yeast, lactic acid bacteria, and Enterobacteriaceae counts compared to the free thymol-containing coating. Results showed that the application of NE and NLC containing alginate-based coating (with the preference for NLC) improved the postharvest quality of carrot and extended its shelf life. Meanwhile, the separate application of these systems gave better results than the simultaneous application of both systems in one sample.

Improving the performance of Ca-alginate films through incorporating zein-caseinate nanoparticles-loaded cinnamaldehyde

This study aimed to fabricate and characterize the Ca-alginate films functionalized by incorporating zein nanoparticles containing cinnamaldehyde (CA). The zein nanoparticles were coated with Na-caseinate (CN) to inhibit the precipitation of zein in the alginate solution. Afterward, the physical, mechanical, morphological, and barrier properties of the nanocomposite films were evaluated. The particle sizes of different zein nanoparticles (with/without CA and CN) ranged between 43.58 and 251.66 nm. The addition of free CA, zein, and CN nanoparticles significantly increased the thickness, opacity, thermal stability, and water contact angle and improved the mechanical properties of the films. The water vapor permeability was not affected but the antimicrobial activity was improved on fresh-cut apples. The lightness of nanocomposite films decreased and the yellowness and greenness increased. According to SEM and AFM images, a dense and organized interlayer arrangement with a rougher surface was detected in the nanocomposite films. FTIR analysis showed that no new interactions were formed between the Ca-alginate and zein/CN nanoparticles. An excellent sustained CA release into the water was observed for the CA/zein nanoparticles-loaded alginate films. Overall, the results showed that Ca-alginate nanocomposite films of zein nanoparticles have good potential to carry hydrophobic bioactive compounds for specific pharmaceutical and food applications.

Carvacrol Microemulsion vs. Nanoemulsion as Novel Pork Minced Meat Active Coatings

Carvacrol is well documented for its antibacterial and antioxidant effects. However, its high volatility has directed researchers toward nanoencapsulation technology according to bioeconomy and sustainability trends. This study examined and compared free carvacrol (FC), carvacrol microemulsion (MC), carvacrol microemulsion busted with chitosan (MMC), and carvacrol nanoemulsions (NC) as active coatings on extending minced pork meat shelf life at 4 ± 1 °C for 9 days, focusing on microbiological, physiochemical, and sensory characteristics. The research involved pre-characterizing droplet sizes, evaluating antioxidants, and determining antibacterial efficacy. The results demonstrated that NC with a 21 nm droplet size exhibited the highest antioxidant and antibacterial activity. All coatings succeeded in extending the preservation of fresh minced pork meat in comparison to the free carvacrol sample (FC). The NC coating showed the highest extension of minced pork meat preservation and maintained meat freshness for 9 days, with a lower TBARs of 0.736 mg MDA/Kg, and effectively reduced mesophilic, lactic acid, and psychotrophic bacterial counts more significantly by 1.2, 2, and 1.3 log, respectively, as compared to FC. Sensory assessments confirmed the acceptability of NC and MCC coatings. Overall, the carvacrol-based nanoemulsion can be considered a novel antioxidant and antimicrobial active coating due to its demonstrated higher efficacy in all the examined tests performed.

Carvacrol-Loaded Phytosomes for Enhanced Wound Healing: Molecular Docking, Formulation, DoE-Aided Optimization, and in vitro/in vivo Evaluation

Background

Despite recent advances in wound healing products, phytochemicals have been considered promising and attractive alternatives. Carvacrol (CAR), a natural phenolic compound, has been reported to be effective in wound healing.

Purpose

This work endeavored to develop novel CAR-loaded phytosomes for the enhancement of the wound healing process.

Methods

Molecular docking was performed to compare the affinities of the different types of phospholipids to CAR. Phytosomes were prepared by three methods (thin-film hydration, cosolvency, and salting out) using Lipoid S100 and Phospholipon 90H with three levels of saturation percent (0%, 50%, and 100%), and three levels of phospholipid molar percent (66.67%, 75%, and 80%). The optimization was performed using Design Expert where particle size, polydispersity index, and zeta potential were chosen as dependent variables. The optimized formula (F1) was further investigated regarding entrapment efficiency, TEM, 1H-NMR, FT-IR, DSC, X-RD, in vitro release, ex vivo permeation, and stability. Furthermore, it was incorporated into a hydrogel formulation, and an in vivo study was conducted to investigate the wound-healing properties of F1.

Results

F1 was chosen as the optimized formula prepared via the thin-film hydration method with a saturation percent and a phospholipid molar percent of zero and 66.67, respectively. TEM revealed the spherical shape of phytosomal vesicles with uniform size, while the results of 1H-NMR, FT-IR, DSC, and X-RD confirmed the formation of the phytosomal complex. F1 demonstrated a higher in vitro release and a slower permeation than free CAR. The wound area of F1-treated animals showed a marked reduction associated with a high degree of collagen fiber deposition and enhanced cellular proliferation.

Conclusion

F1 can be considered as a promising remedy for the enhancement of wound healing and hence it would be hoped to undergo further investigation.

Biochemical, Antioxidant Properties and Antimicrobial Activity of Steno-Endemic Origanum onites

Origanum onites (Lamiaceae) is an Eastern Mediterranean plant that is widely used in Turkish traditional medicine. This study aimed to investigate the biochemical composition, antimicrobial activity, and antioxidant potential of O. onites. In this study, the biochemical composition of the O. onites ethanol extract (OOEt) was analyzed using GC-MS. The antimicrobial activity was investigated using a disk diffusion test and determining minimum inhibitory concentrations (MIC) against 30 microorganism strains, including 28 bacteria (some multidrug-resistant) and 2 fungi. Additionally, the antioxidant activity was evaluated using the DPPH method. The main component identified was carvacrol. OOEt demonstrated antimicrobial activity against a wide range of tested microorganism strains. OOEt displayed the highest activity against E. faecium (a Gram-positive bacterium) at 100 µL with a 52 mm inhibition zone. Additionally, P. aeruginosa DSMZ 50071 and P. fluorescens P1, which are Gram-negative bacteria, were the most sensitive strains with a 24 mm inhibition zone in 100 µL of OOEt. The data obtained from A. baumannii (a multidrug-resistant strain) is particularly striking, as higher activity was observed compared to all positive controls. All tested fungal strains showed more effective results than positive controls. The antioxidant activity of OOEt was found to be stronger than that of the positive control, ascorbic acid. This study determined that O. onites has significant antimicrobial and antioxidant potential.

Research progress of polyphenols in nanoformulations for antibacterial application

Infectious disease is one of the top 10 causes of death worldwide, especially in low-income countries. The extensive use of antibiotics has led to an increase in antibiotic resistance, which poses a critical threat to human health globally. Natural products such as polyphenolic compounds and their derivatives have been shown the positive therapeutic effects in antibacterial therapy. However, the inherent physicochemical properties of polyphenolic compounds and their derivatives limit their pharmaceutical effects, such as short half-lives, chemical instability, low bioavailability, and poor water solubility. Nanoformulations have shown promising advantages in improving antibacterial activity by controlling the release of drugs and enhancing the bioavailability of polyphenols. In this review, we listed the classification and antibacterial mechanisms of the polyphenolic compounds. More importantly, the nanoformulations for the delivery of polyphenols as the antibacterial agent were summarized, including different types of nanoparticles (NPs) such as polymer-based NPs, metal-based NPs, lipid-based NPs, and nanoscaffolds such as nanogels, nanofibers, and nanoemulsions. At the same time, we also presented the potential biological applications of the nano-system to enhance the antibacterial ability of polyphenols, aiming to provide a new therapeutic perspective for the antibiotic-free treatment of infectious diseases.

Hyaluronic Acid Poly(glyceryl)10-Stearate Derivatives: Novel Emulsifiers for Improving the Gastrointestinal Stability and Bioaccessibility of Coenzyme Q10 Nanoemulsions

Fish oils are a rich source of polyunsaturated fatty acids, including eicosapentaenoic acid and docosahexaenoic acid, which are reported to exhibit therapeutic effects in a variety of human diseases. However, these oils are highly susceptible to degradation due to oxidation, leading to rancidity and the formation of potentially toxic reaction products. The aim of this study was to synthesize a novel emulsifier (HA-PG10-C18) by esterifying hyaluronic acid with poly(glyceryl)₁₀-stearate (PG10-C18). This emulsifier was then used to formulate nanoemulsion-based delivery systems to co-deliver fish oil and coenzyme Q10 (Q10). Q10-loaded fish oil-in-water nanoemulsions were fabricated, and then their physicochemical properties, digestibility, and bioaccessibility were measured. The results indicated that the environmental stability and antioxidant activity of oil droplets coated with HA-PG10-C18 surpassed those coated with PG10-C18 due to the formation of a denser interfacial layer that blocked metal ions, oxygen, and lipase. Meanwhile, the lipid digestibility and Q10 bioaccessibility of nanoemulsions formulated with HA-PG10-C18 (94.9 and 69.2%) were higher than those formulated with PG10-C18 (86.2 and 57.8%), respectively. These results demonstrated that the novel emulsifier synthesized in this study could be used to protect chemically labile fat-soluble substances from oxidative damage, while still retaining their nutritional value.

Solid Lipid Nanoparticles vs. Nanostructured Lipid Carriers: A Comparative Review

Solid-lipid nanoparticles and nanostructured lipid carriers are delivery systems for the delivery of drugs and other bioactives used in diagnosis, therapy, and treatment procedures. These nanocarriers may enhance the solubility and permeability of drugs, increase their bioavailability, and extend the residence time in the body, combining low toxicity with a targeted delivery. Nanostructured lipid carriers are the second generation of lipid nanoparticles differing from solid lipid nanoparticles in their composition matrix. The use of a liquid lipid together with a solid lipid in nanostructured lipid carrier allows it to load a higher amount of drug, enhance drug release properties, and increase its stability. Therefore, a direct comparison between solid lipid nanoparticles and nanostructured lipid carriers is needed. This review aims to describe solid lipid nanoparticles and nanostructured lipid carriers as drug delivery systems, comparing both, while systematically elucidating their production methodologies, physicochemical characterization, and in vitro and in vivo performance. In addition, the toxicity concerns of these systems are focused on.

Neuroprotective Potential and Underlying Pharmacological Mechanism of Carvacrol for Alzheimer's and Parkinson's Diseases

The phytochemicals have antioxidant properties to counter the deleterious effects of oxidative stress in the central nervous system and can be a promising drug candidate for neurodegenerative diseases. Among various phytochemicals, constituents of spice origin have recently received special attention for neurodegenerative diseases owing to their health benefits, therapeutic potential, edible nature, and dietary accessibility and availability. Carvacrol, a phenolic monoterpenoid, has garnered attention in treating and managing various human diseases. It possesses diverse pharmacological effects, including antioxidant, anti-inflammatory, antimicrobial and anticancer. Alzheimer's disease (AD) and Parkinson's disease (PD) are major public health concerns that place a significant financial burden on healthcare systems worldwide. The global burden of these diseases is expected to increase in the next few decades owing to increasing life expectancies. Currently, there is no cure for neurodegenerative diseases, such as AD and PD, and the available drugs only give symptomatic relief. For a long time, oxidative stress has been recognized as a primary contributor to neurodegeneration. Carvacrol enhances memory and cognition by modulating the effects of oxidative stress, inflammation, and Aβ25-35- induced neurotoxicity in AD. Moreover, it also reduces the production of reactive oxygen species and proinflammatory cytokine levels in PD, which further prevents the loss of dopaminergic neurons in the substantia nigra and improves motor functions. This review highlights carvacrol's potential antioxidant and anti-inflammatory properties in managing and treating AD and PD.

Nanolipogel Loaded with Tea Tree Oil for the Management of Burn: GC-MS Analysis, In Vitro and In Vivo Evaluation

The GC-MS analysis of tea tree oil (TTO) revealed 38 volatile components with sesquiterpene hydrocarbons (43.56%) and alcohols (41.03%) as major detected classes. TTO efficacy is masked by its hydrophobicity; nanoencapsulation can address this drawback. The results showed that TTO-loaded solid lipid nanoparticles (SLN1), composed of glyceryl monostearate (2% w/w) and Poloxamer188 (5% w/w), was spherical in shape with a core-shell microstructure. TTO-SLN1 showed a high entrapment efficiency (96.26 ± 2.3%), small particle size (235.0 ± 20.4 nm), low polydispersity index (0.31 ± 0.01), and high negative Zeta potential (−32 mV). Moreover, it exhibited a faster active agent release (almost complete within 4 h) compared to other formulated TTO-SLNs as well as the plain oil. TTO-SLN1 was then incorporated into cellulose nanofibers gel, isolated from sugarcane bagasse, to form the ‘TTO-loaded nanolipogel’ which had a shear-thinning behavior. Second-degree thermal injuries were induced in Wistar rats, then the burned skin areas were treated daily for 7 days with the TTO-loaded nanolipogel compared to the unmedicated nanolipogel, the TTO-loaded conventional gel, and the normal saline (control). The measurement of burn contraction proved that TTO-loaded nanolipogel exhibited a significantly accelerated skin healing, this was confirmed by histopathological examination as well as quantitative assessment of inflammatory infiltrate. This study highlighted the success of the proposed nanotechnology approach in improving the efficacy of TTO used for the repair of skin damage induced by burns.

Nanotechnology in drug and gene delivery

Over the last decade, nanotechnology has widely addressed many nanomaterials in the biomedical area with an opportunity to achieve better-targeted delivery, effective treatment, and an improved safety profile. Nanocarriers have the potential property to protect the active molecule during drug delivery. Depending on the employing nanosystem, the delivery of drugs and genes has enhanced the bioavailability of the molecule at the disease site and exercised an excellent control of the molecule release. Herein, the chapter discusses various advanced nanomaterials designed to develop better nanocarrier systems used to face different diseases such as cancer, heart failure, and malaria. Furthermore, we demonstrate the great attention to the promising role of nanocarriers in ease diagnostic and biodistribution for successful clinical cancer therapy.

Applications and perspectives of polyphenol-loaded solid lipid nanoparticles and nanostructured lipid carriers for foods

Imbalanced nutrition in modern society is one of the reasons for disorders, such as cancer, cardiovascular disease, and diabetes, which have attracted the interest in bioactives (particularly polyphenols) to assist in the balanced diet of modern people. Although stability can be maintained during preparation and storage, the ingested polyphenols undergo harsh gastrointestinal digestion processes, resulting in limited bioaccessibility and low gut-epithelial permeation and bioavailability. Several lipid-based formulations have been proposed to overcome these issues. Solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) have also been highlighted as carrier systems for the oral delivery of lipophilic bioactives, including polyphenols. This paper summarizes the research on the ingredients, production methods, post-processing procedures, general characteristics, and advantages and disadvantages of SLNs and NLCs. Overall, this paper reviews the applications and perspectives of polyphenol-loaded SLNs and NLCs in foods, as well as their regulation, production, storage, and economic feasibility.

Therapeutic Efficacy of Carvacrol-Loaded Nanoemulsion in a Mouse Model of Schistosomiasis

Since praziquantel is the only drug available to treat schistosomiasis, a neglected parasitic disease that affects more than 240 million people worldwide, there is an urgent demand for new antischistosomal agents. Natural compound-loaded nanoparticles have recently emerged as a promising alternative for the treatment of schistosomiasis. Carvacrol is an antimicrobial monoterpene present in the essential oil extracted from several plants, especially oregano (Origanum vulgare). In this study, a carvacrol nanoemulsion (CVNE) was prepared, characterized, and administered orally (200 mg/kg) in a mouse infected with either immature (prepatent infection) or adult (patent infection) Schistosoma mansoni. For comparison, data obtained with an unloaded nanoemulsion (blank formulation), free carvacrol, and the drug of reference praziquantel are also presented. CVNE was more effective than free carvacrol in reducing the worm burden and egg production in both patent and prepatent infections. Favorably, CVNE had a high effect in terms of reducing the number of worms and eggs (85%–90%) compared with praziquantel (∼30%) in prepatent infection. In tandem, carvacrol-loaded nanoemulsion markedly improved antischistosomal activity, showing efficiency in reducing worm and egg burden, and thus it may be a promising delivery system for the treatment of schistosomiasis.

Peppermint essential oil-loaded solid lipid nanoparticle in gelatin coating: Characterization and antibacterial activity against foodborne pathogen inoculated on rainbow trout (Oncorhynchus mykiss) fillet during refrigerated storage

The present study was conducted to determine the characterization and antibacterial activity of peppermint essential oil-loaded solid lipid nanoparticle (PEO-SLN) and its impact on the quality of trout fillet stored at 4 ± 1°C for 12 days. The SLNs were prepared through a bath sonication technique. PEO-SLNs contained 0.2% (w/v) PEO in 2% of lipid phase glycerol monostearate (GMS) and tween 80 (1% w/v) used as a surfactant in the aqueous phase. The characterization parameter of PEO-SLN was evaluated, and the antibacterial activity of PEO-SLNs was conducted under in vitro conditions. Trout samples were analyzed for inoculated Pseudomonas aeruginosa, Listeria monocytogenes, and Escherichia coli O157:H7 during refrigerated storage. The mean particle size of PEO-SLNs was 154.83 ± 1.21 nm with a polydispersity index (PDI) of 0.35 ± 0.01 and zeta potential was about -24.16 ± 0.51 mV. The results indicated that PEO-SLN had higher antibacterial activity than the free form of PEO and also when used in combination with gelatin coating (gel + PEO-SLN) had a significant effect on preventing microbial growth in trout fillets (p < 0.05). The most decreasing rate of P. aeruginosa (1.92 log CFU/g), E. coli O157:H7 (0.71 log CFU/g), and L. monocytogenes count (1.69 log CFU/g) was seen in gel + PEO-SLN. These findings illustrated that PEO-SLNs could potentially be utilized in the food industry to increase the shelf life of fish fillets.

Poly(N-vinylcaprolactam) containing solid lipid polymer hybrid nanoparticles for controlled delivery of a hydrophilic drug gemcitabine hydrochloride

Folic acid tagged and hydrophilic polymer containing solid lipid nanoparticles (SLNs) were formulated for the controlled and targeted delivery of gemcitabine, a hydrophilic drug. Drug loaded SLNs were prepared by double emulsion method and optimized by 32 level factorial design. Then, a hydrophilic polymer, namely, poly(N-vinylcaprolactam) (PVCL) was incorporated in the optimized SLN batch in the first aqueous phase (W1) to obtain solid lipid polymer hybrid nanoparticles (SLPHNs) that were further decorated with folic acid (F-SLPHNs). TEM analysis of SLNs and SLPHNs revealed the spherical shape with no aggregation while SLPHNs showed higher % EE. SLPHNs exhibited limited burst release of gemcitabine compared to SLNs as well as lower overall % release. All the formulations showed good cytocompatibility against MDA-MB-231 cell lines and folic acid-tagged hybrid particles (F-SLPHNs) showed remarkably higher cellular uptake.

Recent Advances in Antimicrobial Nano-Drug Delivery Systems

Infectious diseases are among the major health issues of the 21st century. The substantial use of antibiotics over the years has contributed to the dissemination of multidrug resistant bacteria. According to a recent report by the World Health Organization, antibacterial (ATB) drug resistance has been one of the biggest challenges, as well as the development of effective long-term ATBs. Since pathogens quickly adapt and evolve through several strategies, regular ATBs usually may result in temporary or noneffective treatments. Therefore, the demand for new therapies methods, such as nano-drug delivery systems (NDDS), has aroused huge interest due to its potentialities to improve the drug bioavailability and targeting efficiency, including liposomes, nanoemulsions, solid lipid nanoparticles, polymeric nanoparticles, metal nanoparticles, and others. Given the relevance of this subject, this review aims to summarize the progress of recent research in antibacterial therapeutic drugs supported by nanobiotechnological tools.

Fabrication, characterization, and performance of antimicrobial alginate-based films containing thymol-loaded lipid nanoparticles: Comparison of nanoemulsions and nanostructured lipid carriers

Antimicrobial biopolymer films were prepared by incorporating thymol-loaded nanostructured lipid carriers (NLC) or nanoemulsions (NE) into Ca-alginate solutions. Thymol-loaded-NLCs with thymol/lipid mass ratios of 0.1 and 0.2 were prepared and then used to fabricate NLC/alginate films containing either 20% (NLC20 film) or 10% (NLC10 film) of NLCs. Consequently, these two films had the same total thymol mass fraction: R _{thymol/alginate} = 0.02. A nanoemulsion-loaded film (NE film) containing the same amount of thymol and a neat alginate film (control) were also prepared. Incorporation of the NLCs increased the porosity and surface roughness, thickness, water vapor permeability, and yellowness of the films, but decreased their water contact angle, mechanical strength, and swelling ratio. The release of thymol into the air and into water-ethanol solutions was slower for NLC-loaded than NE-loaded films, moreover being slower for the NLC20 than NLC10 films. The antimicrobial activity of the active films was tested on ground beef samples. Their antimicrobial activity was correlated to their release rates, with the NLC20 film giving the longest protection against the enumerated microorganisms. Our results show that encapsulating antimicrobial essential oils within NLCs was more effective at creating antimicrobial films with sustained release properties than encapsulating them within NEs.

Applications and Prospects of Nanotechnology in Food and Cosmetics Preservation

Cosmetic and food products containing water are prone to contamination during the production, storage, and transit process, leading to product spoilage and degraded organoleptic characteristics. The efficient preservation of food and cosmetics is one of the most important issues the industry is facing today. The use of nanotechnology in food and cosmetics for preservation purposes offers the possibility to boost the activity of antimicrobial agents and/or promote their safer distribution into the end product upon incorporation into packaging or film constructions. In this review, current preservation strategies are discussed and the most recent studies in nanostructures used for preservation purposes are categorized and analyzed in a way that hopefully provides the most promising strategies for both the improvement of product safety and shelf-life extension. Packaging materials are also included since the container plays a major role in the preservation of such products. It is conclusively revealed that most of the applications refer to the nanocomposites as part of the packaging, mainly due to the various possibilities that nanoscience offers to this field. Apart from that, the route of exposure being either skin or the gastrointestinal system involves safety concerns, and since migration of nanoparticles (NPs) from their container can be measured, concerns can be minimized. Conclusion: Nanomaterial science has already made a significant contribution to food and cosmetics preservation, and rapid developments in the last years reinforce the belief that in the future much of the preservation strategies to be pursued by the two industries will be based on NPs and their nanocomposites.

Exploiting the Redox Activity of MIL-100(Fe) Carrier Enables Prolonged Carvacrol Antimicrobial Activity

The design of efficient food contact materials that maintain optimal levels of food safety is of paramount relevance to reduce the increasing number of foodborne illnesses. In this work, we develop a smart composite metal-organic framework (MOF)-based material that fosters a unique prolonged antibacterial activity. The composite is obtained by entrapping a natural food preserving molecule, carvacrol, into a mesoporous MIL-100(Fe) material following a direct and biocompatible impregnation method, and obtaining particularly high payloads. By exploiting the intrinsic redox nature of the MIL-100(Fe) material, it is possible to achieve a prolonged activity against Escherichia coli and Listeria innocua due to a triggered two-step carvacrol release from films containing the carvacrol@MOF composite. Essentially, it was discovered that based on the underlying chemical interaction between MIL-100(Fe) and carvacrol, it is possible to undergo a reversible charge-transfer process between the metallic MOF counterpart and carvacrol upon certain chemical stimuli. During this process, the preferred carvacrol binding site was monitored by infrared, Mössbauer, and electron paramagnetic resonance spectroscopies, and the results are supported by theoretical calculations.

Nano-Antibacterials Using Medicinal Plant Components: An Overview

Gradual emergence of new bacterial strains, resistant to one or more antibiotics, necessitates development of new antibacterials to prevent us from newly evolved disease-causing, drug-resistant, pathogenic bacteria. Different inorganic and organic compounds have been synthesized as antibacterials, but with the problem of toxicity. Other alternatives of using green products, i.e., the medicinal plant extracts with biocompatible and potent antibacterial characteristics, also had limitation because of their low aqueous solubility and therefore less bioavailability. Use of nanotechnological strategy appears to be a savior, where phytochemicals are nanonized through encapsulation or entrapment within inorganic or organic hydrophilic capping agents. Nanonization of such products not only makes them water soluble but also helps to attain high surface to volume ratio and therefore high reaction area of the nanonized products with better therapeutic potential, over that of the equivalent amount of raw bulk products. Medicinal plant extracts, whose prime components are flavonoids, alkaloids, terpenoids, polyphenolic compounds, and essential oils, are in one hand nanonized (capped and stabilized) by polymers, lipids, or clay materials for developing nanodrugs; on the other hand, high antioxidant activity of those plant extracts is also used to reduce various metal salts to produce metallic nanoparticles. In this review, five medicinal plants, viz., tulsi (Ocimum sanctum), turmeric (Curcuma longa), aloe vera (Aloe vera), oregano (Oregano vulgare), and eucalyptus (Eucalyptus globulus), with promising antibacterial potential and the nanoformulations associated with the plants' crude extracts and their respective major components (eugenol, curcumin, anthraquinone, carvacrol, eucalyptus oil) have been discussed with respect to their antibacterial potency.

Nanomaterials in the Management of Gram-Negative Bacterial Infections

The exploration of multiplexed bacterial virulence factors is a major problem in the early stages of Escherichia coli infection therapy. Traditional methods for detecting Escherichia coli (E. coli), such as serological experiments, immunoassays, polymerase chain reaction, and isothermal microcalorimetry have some drawbacks. As a result, detecting E. coli in a timely, cost-effective, and sensitive manner is critical for various areas of human safety and health. Intelligent devices based on nanotechnology are paving the way for fast and early detection of E. coli at the point of care. Due to their specific optical, magnetic, and electrical capabilities, nanostructures can play an important role in bacterial sensors. Another one of the applications involved use of nanomaterials in fighting microbial infections, including E. coli mediated infections. Various types of nanomaterials, either used directly as an antibacterial agent such as metallic nanoparticles (NPs) (silver, gold, zinc, etc.), or as a nanocarrier to deliver and target the antibiotic to the E. coli and its infected area. Among different types, polymeric NPs, lipidic nanocarriers, metallic nanocarriers, nanomicelles, nanoemulsion/ nanosuspension, dendrimers, graphene, etc. proved to be effective vehicles to deliver the drug in a controlled fashion at the targeted site with lower off-site drug leakage and side effects.

Solid-lipid nanoparticles (SLN)s containing Zataria multiflora essential oil with no-cytotoxicity and potent repellent activity against Anopheles stephensi

Malaria is still a global health concern with more than 400,000 death annually. Personal protection using mosquitoes' repellent is an effective prevention strategy, especially in endemic areas. The toxic effects of synthetics repellents and their adverse effects on fabricated goods have made the development of green repellent critical. In this study, ingredients of Zataria multiflora essential oil (ZMEO) were identified using GC-MS analysis. Solid-lipid nanoparticles containing ZMEO (1%) were prepared (SLN-ZMEO) using the high-pressure homogenizer method. The repellent activity of ZMEO and SLN-ZMEO was investigated using Klun and Debboun method and compared together. Besides, their cytotoxicity on a human skin normal cell line (HFFF2) was evaluated. Five major components of ZMEO were carvacrol (27.05%), thymol (26.452%), γ-terpinene (15.144%), o-cymene (13.584%), and α-pinene (9.483%). The SLN-ZMEO showed a spherical shape with a particle size of 134 ± 7 nm. Moreover, their polydispersity index (PDI), zeta potential and entrapment efficiency were determined as 0.24 ± 0.1, - 9.82 ± 0.95 mV and 64.6 ± 3.8%, respectively. Interestingly, the protection time of nanoformulation (93 ± 5 min) was three times longer than that of the non-formulated essential oil (29 ± 2 min). Interestingly, both samples did not show cytotoxicity on HFFF2. Therefore, the prepared nanoformulation can be used as a green and potent repellent.

Carvacrol Prodrugs with Antimicrobial Activity Loaded on Clay Nanocomposites

Background: Carvacrol, an essential oil with antimicrobial activity against a wide range of pathogens, and its water soluble carvacrol prodrugs (WSCP1-3) were intercalated into montmorillonite (VHS) interlayers to improve their stability in physiological media and promote their absorption in the intestine. Methods: Intercalation of prodrugs by cation exchange with montmorillonite interlayer counterions was verified by X-ray powder diffraction and confirmed by Fourier transform infrared spectroscopy and thermal analysis. Results: In vitro release studies demonstrated that montmorillonite successfully controlled the release of the adsorbed prodrugs and promoted their bioactivation only in the intestinal tract where carvacrol could develop its maximum antimicrobial activity. The amount of WSCP1, WSCP2, and WSCP3 released from VHS were 38%, 54%, and 45% at acid pH in 120 min, and 65%, 78%, and 44% at pH 6.8 in 240 min, respectively. Conclusions: The resultant hybrids successfully controlled conversion of the prodrugs to carvacrol, avoiding premature degradation of the drug.

Physicochemical and antibacterial properties of fabricated ovalbumin–carvacrol gel nanoparticles

The applications of carvacrol are limited due to its poor stability, water solubility and high volatility. Herein we fabricated ovalbumin–carvacrol gel nanoparticles and then improved solubility, stability and antibacterial property of carvacrol.