Preparation, characterization and in vitro release study of carvacrol-loaded chitosan nanoparticles

Optimizing the Method of Rosemary Essential Oils Extraction by Using Response Surface Methodology (RSM)-Characterization and Toxicological Assessment

Rosemary (Rosmarinus officinalis L.) is a plant with needle-shaped leaves. It is mainly found in Mediterranean regions (Algeria, Morocco and Tunisia). Rosemary essential oil (EO) has several therapeutic virtues that were widely studied. However, the use of this EO is restricted due to its sensitivity to oxidation. Nanoencapsulation based on EO and polymers has been developed as one of the promising techniques to overcome this limitation. In this study, the emphasis was on optimizing the extraction and formulation of a food additive based on rosemary EO. In fact, the results showed that rosemary EO extraction depended on the parameters of the extraction process, and the optimum heating temperature and extraction time were determined using an experimental design methodology. The parameters for extraction were chosen as follows: heating temperature of 250 °C and a hydrodistillation time of 180 min. This optimization revealed that the maximum oil yield can be obtained. Rosemary EO was characterized by a dominance of 1,8-cineole, camphor, α-pinene, borneol and camphene as well as by high antioxidant and antibacterial capacities with low acute toxicity. The obtained formulation of a stable rosemary EO powder can be used as a food additive in several industrial applications.

Improvement of salicylic acid biological effect through its encapsulation with silica or chitosan

Attacks of necrotrophic and biotrophic fungi affect a large number of crops worldwide and are difficult to control with fungicides due to their genetic plasticity. Encapsulation technology is a good alternative for controlling fungal diseases. In this work, encapsulated samples of salicylic acid (SA) with silica (Si:SA) or chitosan (Ch:SA) at three different ratios were prepared by spray drying, and morphological and physicochemical characterised. Therefore, size distribution, specific surface area, thermal stability, encapsulation efficiency, and in-vitro SA release were determined. Biological activity of encapsulated samples were tested against different fungi of agricultural interest at various concentrations (0-1000 µM). Treatments prepared with the lowest ratios for both capsules, were found to have the best antifungal effect in an in vitro system, inhibiting the mycelial growth of Alternaria alternata, Botrytis cinerea, Fusarium oxysporum and Geotrichum candidum. Similarly, treatments with the lowest ratios of both encapsulated samples reduced free SA toxicity on Arabidopsis thaliana seeds. In this system, plants treated with capsules had higher root and rosette development than those treated with free SA. In conclusion, a product with a great potential in agriculture that shows high antifungal capacity and low toxicity for plants have been developed through a controlled and industrially viable process.

Comparative evaluation of carvacrol and eugenol chitosan nanoparticles as eco-friendly preservative agents in cosmetics

The current status of controversy regarding the use of certain preservatives in cosmetic products makes it necessary to seek new ecological alternatives that are free of adverse effects on users. In our study, two different natural terpenes Carvacrol and Eugenol were encapsulated in chitosan nanoparticles in different ratios of Chitosan:terpene. The nanoparticles were characterized by DLS and TEM showing a maximum particle size of 100 nm. The chemical structure, thermal properties, and release profile of terpenes were evaluated showing a successful protection of terpene in Chitosan matrix. Two different release profile were observed showing a faster release profile in the case of Eugenol. Antimicrobial properties of nanoparticles were evaluated against typical microbial contaminants found in cosmetic products, showing higher antimicrobial properties with chitosan encapsulation of terpenes. Furthermore, natural moisturizing cream inoculated with beforementioned microorganisms was formulated with Carvacrol-chitosan nanoparticles and Eugenol-chitosan nanoparticles to evaluate the preservative efficiency, indicating a highest preservative efficiency with the use of Eugenol-chitosan nanoparticles.

Folate functionalized chitosan nanoparticles as targeted delivery systems for improved anticancer efficiency of cytarabine in MCF-7 human breast cancer cell lines

Anticancer drug cytarabine, has been widely used for treating haematological malignancies while it has minimal activity against solid tumours, which demands continuous infusion leading to high dose cytarabine toxicity. In this study, folate conjugated chitosan nanoparticles (FCCNP) were used for targeted delivery of cytarabine in breast adenocarcinoma cell lines by making use of the overexpressed folate receptors on the surface of MCF-7. Folate was conjugated to chitosan using carbodiimide. FCCNPs show spherical morphology with a size of<50 nm. Zeta potential of + 45.2 mV and PDI of 0.98 from DLS measurement confirms a stable monodisperse nanoformulation. Cytotoxicity was studied in folate receptor positive, MCF-7 and folate receptor negative, A-549 cell lines. Increased cellular uptake of the drug incorporated nanoparticles was confirmed in MCF-7 cells with fluorophore, squaraine 650 compared to A-549 cells. The relative fold of expression of genes involved in apoptosis such as bax, cyt c and cas 9 were upregulated. The present in vitro study confirms improved cytotoxicity of cytarabine folate conjugated chitosan nanoparticles in MCF-7 cells.

Chitosan-based nanoencapsulation of Toddalia asiatica (L.) Lam. essential oil to enhance antifungal and aflatoxin B1 inhibitory activities for safe storage of maize

The present study reports the enhanced antifungal, aflatoxin B₁ (AFB₁) inhibitory activities and mode of action of chitosan-based nanoencapsulated Toddalia asiatica essential oil (neTAEO). Twenty-seven different chemical components were recognized from T. asiatica essential oil (TAEO) using gas chromatography-mass spectrometry (GC-MS). The caryophyllene oxide (CO) (25.4%), and 1,3-hexadiene, 3-ethyl-2,5-dimethyl- (HED) (24.08%) were documented as significant compounds. The Z-average particles diameter (Z-APD) of the neTAEO ranged between 18.41 and 131.8 nm. The neTAEO showed enhanced and most promising antifungal and AFB₁ inhibitory activity than TAEO. In viable maize model assay, neTAEO effectively preserved the maize from fungal invade and AFB₁ biosynthesis. The neTAEO significantly disturbs membrane integrities of Aspergillus flavus by inhibiting ergosterol biosynthesis followed by the extreme release of ions (Mg²⁺ and K⁺) and UV-absorbing (260 and 280 nm) cellular constituents. The in-silico molecular docking showed that the major active components of TAEO viz., CO and HED were active against AFB₁ synthesizing leading genes Ver-1 and Omt-A with docking scores ranging from -4.8 to -7.7. The obtained results confirm that neTAEO showed promising antifungal and AFB₁ inhibitory activities; hence, it could be used as an alternative green strategy to protect food grains from fungal invade and AFB₁ production during storage.

Chitosan nanoparticles loaded with garlic essential oil: A new alternative to tebuconazole as seed dressing agent

In this study, garlic essential oil (GEO) has been encapsulated in chitosan nanoparticles (NPCH) with sodium tripolyphosphate (TPP). Fourier transform infrared (FT-IR) spectroscopy, UV-vis spectrophotometry, thermogravimetric analysis (TGA) and X-ray diffraction (XRD) techniques were applied to characterize GEO-NPCH. The obtained nanoparticles exhibited a regular distribution and spherical shape with size range of 200-400 nm as revealed by scanning electron microscopy (SEM). The maximum encapsulation efficiency (EE) and loading capacity (LC) of GEO-loaded chitosan nanoparticles were about 32.8% and 19.8% respectively. Nanoparticle formulations of GEO were found to have antifungal activity against Aspergillus versicolor, A. niger and Fusarium oxysporum. In addition, they showed growth promoting effects by increasing emergence, shoot and root fresh weight on wheat, oat and barley.

Synthesis and characterization of chitosan nanoparticles loaded with greater celandine (Chelidonium majus L.) essential oil as an anticancer agent on MCF-7 cell line

Essential oils (EOs) of greater celandine (GC) roots and leaves were extracted, and gas chromatography-mass spectrometry (GC-MS) was used for analyzing them. Then they were loaded into chitosan nanoparticles (CNPs) using emulsion-ionic gelation method. CNPs loaded with greater celandine root essential oil (GCREO) and leave essential oil (GCLEO) were synthesized (size 76.5-115.3 nm) using an emulsion-ionic gelation method. Fourier Transform Infrared (FT-IR), spectroscopy, scanning electron microscope (SEM), and dynamic light scattering (DLS) were used for characterization of the formed NPs. Good encapsulation efficiency was confirmed for GCREO (62.5%) and GCLEO (69.1%) in CNPs. According to the MTT results, the synthesized NPs showed a dose-dependent effect on MCF-7 cell line. The inhibitory concentration (IC₅₀) values for GCREO, GCLEO, CSNRs-GCREO and CNPs-GCLEO samples were 126.4, 90.2, 77.6, and 41.5 μg/mL, respectively. The highest rate of apoptosis was obtained in the CNPs-GCLEO group (63.73%). The results revealed that the cytotoxicity of CSNRs-GCREO and CNPs-GCLEO against MCF-7 cell line was significantly higher than that of their free form, implying that encapsulation of GCREO and GCLEO in CNPs is an efficient technique for improving their anti-cancer activity against MCF-7 cell line.

Inhibitory activities of phloroglucinol-chitosan nanoparticles on mono- and dual-species biofilms of Candida albicans and bacteria

Phloroglucinol (PG) was encapsulated into chitosan nanoparticles (CSNPs) using a simple ionic gelification technique, and the inhibitory activity of the resulting nanoparticles on microbial mono- and dual-species biofilms was investigated. PG-CSNPs were determined to be spherical with a rough surface, and had an average diameter and zeta potential of 414.0 ± 48.5 nm and 21.1 ± 1.2 mV, respectively. The rate of PG release from the loaded CSNPs was found to increase in acidic environment. The loading capacity and encapsulation efficiency of PG to CSNPs were determined to be 18.74% and 22.4%, respectively. The prepared PG-CSNPs exhibited inhibitory effects on mono-species biofilms such as Candida albicans, Staphylococcus aureus, Klebsiella pneumoniae, Streptococcus mutans, and dual-species such as C. albicans-K. pneumoniae/S. aureus/S. mutans. The PG-CSNPs were found to be more effective in inhibiting and eradicating mono- and dual-species biofilms than pure PG. In addition, PG-CSNPs were found to enhance the efficacy of several antimicrobial drugs against mature mono- and dual-species biofilms. This work demonstrates that PG-CSNPs may provide an alternative method for treating infections caused by biofilm-forming pathogens.

Fabrication and characterization of 3D printing scaffold technology by extract oils from plant and its applications in the cardiovascular blood

Extract oils from plants used in 3D polysaccharides modified with natural protein polymer modified polymer scaffolds can help to reduce blood pressure. This study aimed to use extract oils from plant (EOP)as blood pressure-reducing, bind them to magnetic iron nanoparticles (Fe3O4@NPs), then bind them to polymeric 3D print scaffolds [chitosan, polylactic acid, and polyurethane (CS/PLA/PU), modified with natural protein and finally separate them. This method made it possible to investigate different variables for nanoparticles. In this project, synthesis polymer, modified gelatin (Mo-Ge), PEGylation, extract oils from plant loading and release process in nanocarrier with different concentrations were examined and cell proliferation was optimized. The results show that 75% of the extract oils from plant loaded on iron magnetic nanoparticles containing PEGylated polymer scaffolds was released. Cell proliferation was performed for the sample. In this process, modification of scaffolding with polysaccharides modified with natural protein and extract oils from plant increased the efficiency of nanoparticles among the studied Allium sativum and Zingiber officinale. The size of A. sativum and Z. officinale were 29.833 nm and 150.02 nm size, respectively. These behaved very similarly to each other and A. sativum had the biggest effect in lowering blood pressure. The application of extract oils from plant in 3D mode scaffolding has not been studied before and this is the first analysis to do so, using nanoparticles.

Antifungal Carvacrol Loaded Chitosan Nanoparticles

The increased prevalence and incidence of fungal infections, of which Candida albicans represents one of the most life-threatening organisms, is prompting the scientific community to develop novel antifungal molecules. Many essential oils components are attracting attention for their interesting antifungal activities. Given the chemical and physical characteristics of these compounds, the use of appropriate nanodelivery systems is becoming increasingly widespread. In this study, chitosan nanoparticles were prepared using an ionic gelation procedure and loaded with the phenolic monoterpene carvacrol. After a bioassay guided optimization, the best nanoparticle formulation was structurally characterized by means of different spectroscopic (UV, FTIR and DLS) and microscopy techniques (SEM) and described for their functional features (encapsulation efficiency, loading capacity and release kinetics). The antifungal activity of this formulation was assayed with different Candida spp., both in planktonic and biofilm forms. From these studies, it emerged that the carvacrol loaded nanoparticles were particularly active against planktonic forms and that the antibiofilm activity was highly dependent on the species tested, with the C. tropicalis and C. krusei strains resulting as the most susceptible.

Chitosan nanoparticles encapsulating lemongrass (Cymbopogon commutatus) essential oil: Physicochemical, structural, antimicrobial and in-vitro release properties

This study was aimed to encapsulate lemongrass (Cymbopogon commutatus) essential oil (LGEO) into chitosan nanoparticles (CSNPs) and to investigate their physicochemical, morphological, structural, thermal, antimicrobial and in-vitro release properties. CSNPs exhibited spherical morphology with an average hydrodynamic size of 175-235 nm. Increasing EO loading increased the average size of CSNPs from 174 to 293 nm (at CS:EO ratio from 1:0 to 1:1.25). SEM and AFM confirmed the results obtained by hydrodynamic size indicating that EO loading led to formation of large aggregated NPs. The successful physical entrapment of EO within NPs was shown by fourier-transform infrared spectroscopy. X-ray diffractogram of loaded-CSNPs compared to non-loaded CSNPs exhibited a broad high intensity peak at 2θ = 19-25° implying the entrapment of LGEO within CSNPs. Thermogravimetric analysis (TGA) showed that encapsulated EO was decomposed at a temperature of 252 °C compared to a degradation temperature of 126 °C for pure LGEO, indicating a two-fold enhancement in thermal stability of encapsulated CSNPs. Differential scanning calorimetry also proved the physical entrapment of EO into polymeric matrix of chitosan. In-vitro release study showed a time- and pH-dependent release of EO into release media demonstrating a three-stage release behavior with a rapid initial release of EO, followed by a steady state migration of EO from its surrounding envelope at the later stages. Antimicrobial assay showed strong antimicrobial properties of free form of LGEO against the bacteria (both gram positive and gram negative) and fungi species tested. Moreover, loaded-CSNPs exhibited stronger antibacterial and anti-fungal activities than non-loaded CSNPs.

Enhanced antibacterial activity of lysozyme loaded quaternary ammonium chitosan nanoparticles functionalized with cellulose nanocrystals

In this study, cellulose nanocrystals (CNC) as functional cross-linker and Pickering emulsifier was used to stabilize Lysozyme (Lys) encapsulated in quaternary ammonium chitosan nanoparticles (QC NPs) via ionic gelation method. Physicochemical, structural, and antibacterial properties of the CNC stabilized Lys loaded QC NPs were also evaluated. Particle size, particle size distribution, Zeta potential (ZP), and spectroscopic analyses showed the successful encapsulation of Lys. Antibacterial activity of NPs against Staphylococcus aureus and Vibrio parahaemolyticus was investigated on the basis of inhibition zone (IZ), minimum inhibitory concentration (MIC), and minimum bacterial concentration (MBC). MIC and MBC of CNC stabilized Lys loaded HQC NPs against S. aureus were 0.094 and 0.188 while corresponding values for CNC stabilized Lys loaded LQC NPs V. parahaemolyticus were 0.156 and 0.312 mg/mL, respectively. Therefore, CNC stabilized Lys loaded QC NPs have potential implications in the food industry for food preservation and packaging.

Characterization of Oregano Essential Oil (Origanum vulgare L. subsp. hirtum) Particles Produced by the Novel Nano Spray Drying Technique

Oregano essential oil (OEO), due to its wide variety of biological activities, could be a “green” alternative to chemical preservatives. On the other hand, the difficulties in its use or storage have turned researchers’ interest in encapsulation strategies as a way to face stability and handling issues. Fabrication of OEO-loaded particles, using nano spray drying technique (NSD) and whey protein isolate-maltodextrin mixtures (1:1, 1:3) as wall materials appears to be a novel and promising strategy. The obtained particles were characterized in terms of volatile composition, encapsulation efficiency, and physicochemical, molecular, morphological, and antibacterial properties. The results confirmed that encapsulation of OEO using NSD achieved high levels of powder recovery (>77%) and encapsulation efficiency (>98%) while assisting in the retention of the main bioactive compounds. The partial replacement of WPI by MD significantly affected particles’ physical properties. FTIR analyses revealed the possible structural stabilization of core and wall materials, while SEM verified the very fine size and spherical shape. Finally, antibacterial studies demonstrated their activity against Escherichia coli and Staphylococcus aureus, which is much stronger in comparison with that of pure OEO, proving the positive effect of NSD and particles’ potential in future food applications.

Improvement of the Antimicrobial Activity of Oregano Oil by Encapsulation in Chitosan-Alginate Nanoparticles

Oregano oil (OrO) possesses well-pronounced antimicrobial properties but its application is limited due to low water solubility and possible instability. The aim of this study was to evaluate the possibility to incorporate OrO in an aqueous dispersion of chitosan—alginate nanoparticles and how this will affect its antimicrobial activity. The encapsulation of OrO was performed by emulsification and consequent electrostatic gelation of both polysaccharides. OrO-loaded nanoparticles (OrO-NP) have small size (320 nm) and negative charge (−25 mV). The data from FTIR spectroscopy and XRD analyses reveal successful encapsulation of the oil into the nanoparticles. The results of thermogravimetry suggest improved thermal stability of the encapsulated oil. The minimal inhibitory concentrations of OrO-NP determined on a panel of Gram-positive and Gram-negative pathogens (ISO 20776-1:2006) are 4–32-fold lower than those of OrO. OrO-NP inhibit the respiratory activity of the bacteria (MTT assay) to a lower extent than OrO; however, the minimal bactericidal concentrations still remain significantly lower. OrO-NP exhibit significantly lower in vitro cytotoxicity than pure OrO on the HaCaT cell line as determined by ISO 10993-5:2009. The irritation test (ISO 10993-10) shows no signs of irritation or edema on the application site. In conclusion, the nanodelivery system of oregano oil possesses strong antimicrobial activity and is promising for development of food additives.

Development and characterization of catechin-in-cyclodextrin-in-phospholipid liposome to eradicate MRSA-mediated surgical site infection: Investigation of their anti-infective efficacy through in vitro and in vivo studies

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the prime pathogens responsible for surgical site infection (SSI). Treatment of SSI remains challenging because of resistant nature of MRSA, which is a major threat in recent years. Our previous work revealed the antibacterial potential of catechin isolated from cashewnut shell against MRSA. However, the application of catechin to treat MRSA-mediated SSI is hampered because of its poor solubility and low trans-dermal delivery. Hence, the present study focused on developing catechin-in-cyclodextrin-in-phospholipid liposome (CCPL) and evaluating its physicochemical characteristics and anti-infective efficacy through in vitro and in vivo models. Encapsulation of catechin with β-cyclodextrin and soybean lecithin was confirmed through UV-Vis spectroscopy, FTIR, and XRD techniques, while TEM imaging revealed the size of CCPL (206 nm). The CCPL displayed a higher level of water solubility (25.13%) and in vitro permeability (42.14%) compared to pure catechin. A higher level of encapsulation efficiency (98.9%) and antibacterial activity (19.8 mm of ZOI and 31.25 μg/mL of MIC) were noted in CCPL compared to the catechin/cyclodextrin complex. CCPL recorded significant and dose-dependent healing of the incision, significant reduction of bacterial count, improved epithelization, and effective prevention of inflammation in skin samples of SSI-induced Balb/c mice. Data of the present work suggest that the CCPL could be considered as a novel and potential candidate to mitigate MRSA-mediated SSI after clinical trials.

Carvacryl acetate nanoencapsulated with chitosan/chichá gum exhibits reduced toxicity in mice and decreases the fecal egg count of sheep infected with gastrointestinal nematodes

The nanoencapsulation of biocomposites with anthelmintic action has been proposed as an alternative for improving their efficiency. Thus, the current study aimed to evaluate the efficacy of carvacryl acetate nanoencapsulated with biopolymers (nCVA) in the control of sheep gastrointestinal nematodes. CVA was nanoencapsulated with chitosan/chichá gum and characterized in terms of its efficacy of encapsulation (EE), yield and zeta potential. The acute toxicity of nCVA was evaluated in mice. For the fecal egg count reduction test, 40 animals were divided into four groups (n = 10) and orally administered the following treatments: G1, 250 mg kg−1 CVA; G2, 250 mg kg−1 nCVA; G3, chitosan/chichá gum (negative control) and G4, 2.5 mg kg−1 monepantel (positive control). Feces were collected on days 0 and 16 posttreatment to determine the eggs per gram of feces (epg). The EE and yield of nCVA were 72.8 and 57.5%, respectively. The nanoparticles showed a size of 764.5 ± 302.5 nm, and the zeta potential at pH 3.2 was +22.0 mV. nCVA presented a 50% lethal dose (LD50) of 2609 mg kg−1. By 16 days posttreatment, CVA, nCVA and monepantel reduced the epg by 52.9.7, 71.5 and 98.7%, respectively, and the epg of sheep treated with nCVA differed from that of the negative control (P > 0.05) but did not differ from that of sheep treated with CVA. In conclusion, the nanoencapsulation of CVA reduced its toxicity, and nCVA showed anthelmintic activity.

Wound-aided semi-solid poly(vinyl alcohol) hydrogels incorporating essential oil-loaded chitosan nanoparticles

The potential of chitosan nanoparticles (CSNPs) loaded with essential oil (EO) incorporated into semi-solid PVA hydrogels for use in wound management was studied. Two types of essential oil were compared including clove essential oil (CEO) and turmeric essential oil (TEO). The EO-loaded CSNPs were prepared by a two-step method; oil-in-water (o/w) emulsification followed by ionic gelation using different ratios of chitosan:EO (i.e., 1:0.25, 1:0.50, 1:0.75, and 1:1.00 w/w). The increasing amount of EO caused more aggregate structure as observed from SEM images. The TEO-loaded CSNPs showed a higher extent of aggregation than the CEO-loaded CSNPs. The adhesiveness of the semi-solid PVA hydrogels containing TEO-loaded CSNPs was the highest. The use of EO-loaded CSNPs in the semi-solid PVA hydrogel helped to sustain and prolong the release rate of EO from the hydrogels as compared to just the EO alone. The studied semi-solid PVA hydrogels were non-toxic to both NCTC clone 929 and NHDF cells. Overall results suggested that these semi-solid hydrogels are good candidates for use in wound management.

High antibacterial performance of hydrophobic chitosan-based nanoparticles loaded with Carvacrol

Bacterial infections have become one of the top ten public health concerns worldwide. These problems are aggravated with the emergence of multi-drug resistant bacterial strains. Thus, it is necessary to adopt novel technological strategies, such as development of bionanomaterials to prevent the infection, and treat this kind of bacteria. At this regard, the chemical modification of chitosan (Cs), by the covalent attachment of a hydrocarbon chain (octanoic acid), was developed to obtain hydrophobic chitosan (HCs). Then, HCs was used to synthetize nanoparticles using the well-known ionotropic gelation approach, optimizing the parameters, such as the TPP/HCs ratio and pH solution to get stable nanoparticles. Then, carvacrol (CAR) was loaded into NPs (HCs-CAR NPs) using different concentrations of 25%, 50% and 75% (%w/w CAR/HCs). The physicochemical properties for HCs-CAR NPs prepared at 50% of CAR stood out from the rest, showing a spherical morphology, with a size of 200 nm, Z potential of 10.4 mV and encapsulation efficiency of 56.28%. These formulations were chosen to evaluate the antibacterial activity, using Gram-negative (Escherichia coli) and Gram-positive bacterial model (Staphylococcus aureus). The HCs-CAR NPs showed great activity against both bacterial models, being more effective against Gram (+) strain (S. aureus), suggesting the potential application of these NPs as novel biomaterial to treat bacterial infection.

Development and Characterization of Bioactive Polypropylene Films for Food Packaging Applications

Bioactive polypropylene (PP) films with active agents) presence for food packaging application have been prepared and characterized. The novel modified PP films were obtained via PP/additives systems regranulation and cast extrusion. The influence of two types of plasticizers (natural agents as well as commercial synthetic product) and bioactive additives on final features, e.g., mechanical properties, was evaluated. Moreover, the biocidal activity of the films was determined. Due to their functional properties, they are developed as additives to packaging plastic materials such as polyolefins. The study results presented in our work may indirectly contribute to environmental protection by reducing food waste. The aim of the work was to obtain innovative, functional packaging materials with an ability to prolong the shelf life of food products. The best antimicrobial properties were observed for the sample based on 5 wt.% oregano oil (OO) and 5 wt.% cedar oil (OC) in PP matrix. A microbial test revealed that the system causes total reduction in the following microorganisms: B. subtilis, E. coli, S. aureus, P. putida, C. albicans, A. alternata, F. oxysporum.

Therapeutic effects of chitosan-embedded vitamin C, E nanoparticles against cisplatin-induced gametogenic and androgenic toxicity in adult male rats

Cisplatin, an anticancer drug used in treating various types of cancers, can cause reproductive toxicities during chemotherapy. Keeping this in view, the present study was designed to investigate the possible protective effects of normal vitamin C and E and vitamin C and E nanoparticles (embedded in chitosan) against cisplatin-induced reproductive toxicities. Vitamins C, E, and their nanoparticles in this regard proved to be an effective therapy. The work aimed to treat cisplatin-induced reproductive toxicities through vitamin C and E and their nanoparticles. Cisplatin exposure caused significant reduction in the weight, testosterone level, and changed lipid profile. Similarly, cisplatin induced significant widespread testicular atrophy and testicular lesions as evidenced by the gaps in the epithelium and loss of differentiating germ cells. Vitamin C and E and their nanoparticles rescued the weight, testosterone level, and testicular disturbances, which is associated with improved histological view of testicular tissues. The current study highlights evidence that designing a medication of vitamin C and E nanoparticles is useful in mitigating cisplatin-induced reproductive toxicity in cancerous male patients underlying chemotherapy.

Evaluating the Anticarcinogenic Activity of Surface Modified/Functionalized Nanochitosan: The Emerging Trends and Endeavors

Chitosan begins its humble journey from marine food shell wastes and ends up as a versatile nutraceutical. This review focuses on briefly discussing the antioxidant activity of chitosan and retrospecting the accomplishments of chitosan nanoparticles as an anticarcinogen. The various modified/functionalized/encapsulated chitosan nanoparticles and nanoforms have been listed and their biomedical deliverables presented. The anticancer accomplishments of chitosan and its modified composites have been reviewed and presented. The future of surface modified chitosan and the lacunae in the current research focus have been discussed as future perspective. This review puts forth the urge to expand the scientific curiosity towards attempting a variety of functionalization and surface modifications to chitosan. There are few well known modifications and functionalization that benefit biomedical applications that have been proven for other systems. Being a biodegradable, biocompatible polymer, chitosan-based nanomaterials are an attractive option for medical applications. Therefore, maximizing expansion of its bioactive properties are explored. The need for applying the ideal functionalization that will significantly promote the anticancer contributions of chitosan nanomaterials has also been stressed.

Chitosan-Based Anti-Oxidation Delivery Nano-Platform: Applications in the Encapsulation of DHA-Enriched Fish Oil

Refined cobia liver oil is a nutritional supplement (CBLO) that is rich in polyunsaturated fatty acids (PUFAs), such as DHA and EPA; however, PUFAs are prone to oxidation. In this study, the fabrication of chitosan-TPP-encapsulated CBLO nanoparticles (CS@CBLO NPs) was achieved by a two-step method, including emulsification and the ionic gelation of chitosan with sodium tripolyphosphate (TPP). The obtained nanoparticles were inspected by dynamic light scattering (DLS) and showed a positively charged surface with a z-average diameter of between 174 and 456 nm. Thermogravimetric analysis (TGA) results showed the three-stage weight loss trends contributing to the water evaporation, chitosan decomposition, and CBLO decomposition. The loading capacity (LC) and encapsulation efficiency (EE) of the CBLO loading in CS@CBLO NPs were 17.77-33.43% and 25.93-50.27%, respectively. The successful encapsulation of CBLO in CS@CBLO NPs was also confirmed by the Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) techniques. The oxidative stability of CBLO and CS@CBLO NPs was monitored by FTIR. As compared to CBLO, CS@CBLO NPs showed less oxidation with a lower generation of hydroperoxides and secondary oxidation products after four weeks of storage. CS@CBLO NPs are composed of two ingredients that are beneficial for health, chitosan and fish oil in a nano powdered fish oil form, with an excellent oxidative stability that will enhance its usage in the functional food and pharmaceutical industries.

Preparation, characterization and biological activity of proanthocyanidin-chitosan nanoparticles

In this study, proanthocyanidin-loaded chitosan nanoparticles (PC-CS-NPs) were produced using ionotropic gelation and characterized using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and dynamic light scattering (DLS). The synthesized nanoparticles were smaller than 300 nm and had a spherical shape, smooth topography and homogenous morphology as observed through scanning electron microscopy (SEM). In vitro release study showed that proanthocyanidins (PC) had a sustainable release from PC-CS-NPs in different buffer media. PC-CS-NPs had higher or comparable potency in scavenging DPPH and ABTS free radicals as compared to native drugs. Furthermore, PC-CS-NPs also inhibited the growth of four bacteria species, whose degree of inhibition depended on the bacterial strain. The results of SEM confirmed the changes in the microstructure of bacteria. Our findings support the use of chitosan nanoparticles to encapsulate PC and improve its bioactivity in food products.

Effects of three essential oils and their nano-emulsions on Listeria monocytogenes and Shigella flexneri in Egyptian Talaga cheese

Talaga cheese is a soft Egyptian cheese that has been associated with foodborne pathogens such as Listeria monocytogenes and Shigella flexneri. Essential oils (EOs) play a pivotal role in sustainably controlling foodborne diseases and as a potential preservative in soft cheeses. However, limited data is available comparing the antibacterial activity of EOs and their nano-emulsions (NEs) when inoculated into Talaga cheese. Therefore, this study aimed to examine the antibacterial activity of carvacrol, clove, and cumin EOs, in addition to their NEs, against L. monocytogenes (NCTC 13372/ATCC® 7644) and S. flexneri (ATCC®12022^TW⁎) inoculated into laboratory-manufactured Egyptian Talaga cheese during refrigerated storage. The NEs had a Z-average diameter of 32.98 ± 29.75 nm, 45.2 ± 34.25 nm, and 50.23 ± 15.7 nm and a PDI of 0.326, 0.245, and 0.307 for carvacrol, clove, and cumin NEs, respectively. The flow of active functional groups of EOs and NEs as clarified by Fourier-transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM) showed the spherical-shaped droplet structure of the prepared NEs. The minimum inhibitory concentration (MIC) of all EOs and their NEs was 0.78% against L. monocytogenes and 1.56% against S. flexneri, while those of carvacrol EO and its NE were 0.78% against both microorganisms. By supplementation in cheese, NEs significantly reduced the counts of inoculated pathogens from 8.2 log₁₀cfu/g to 1.5 log₁₀cfu/g after 2 to 3 weeks compared to EOs, which reduced them after 4 to 5 weeks. The carvacrol NE showed excellent antibacterial activity with no cheese sensory impairment. It reduced L. monocytogenes by 99% (R%) after 7 days and after 3 weeks for S. flexneri at 0.78% concentration, while higher concentrations and a longer period were required for the other NEs to show an inhibitory effect. NEs showed a greater antimicrobial effect than their non-emulsified counterparts, especially when interacting with food items, and carvacrol NE at a low concentration (0.78%) demonstrated its efficacy as an antibacterial and natural food preservative.

Preparation and optimization of controlled release nanoparticles containing cefixime using Central Composite design: An attempt to enrich its antimicrobial activity

BACKGROUND

Due to the increased resistance against existing antibiotics, research is essential to discover new and alternative ways to control infections induced by resistant pathogens.

OBJECTIVE

The goal of the current scrutinization was to enrich the dissolution rate and antibacterial property of cefixime (CEF) orally.

METHODS

To achieve the desired results, chitosan nanoparticles (NPs) containing CEF were fabricated using the ionic gelation method. Central Composite design has been applied to get the optimal formulation for the delivery of CEF. The effect of three variables such as the concentration of chitosan, tripolyphosphate, and tween 80 on the characteristics of NPs was evaluated.

RESULTS

The optimized NPs were a relatively monodispersed size distribution with an average diameter of 193 nm and a zeta potential of about 11 mV. The scanning tunneling microscope confirmed the size of NPs. The surface morphology of NPs was observed by scanning electron microscopy. The calorimetric analysis indicated the amorphous state of cefixime in the formulation. The dissolution rate of NPs in aqueous media was acceptable and the model of release kinetic for CEF from NPs followed the Peppas model. The potency of CEF in NPs against various types of bacteria was hopefully efficient. The ex- vivo release study demonstrated higher penetration of NPs from the rat intestine compared to free drug. The cell culture study showed the safety of the optimized formulation.

CONCLUSION

It was concluded that CLN could be considered as a prospering system for the controlled delivery of CEF with advantaging its antibacterial effectiveness.

Carvacrol-loaded liposome suspension: optimization, characterization and incorporation into poly(vinyl alcohol) films

The purpose of this study was to encapsulate carvacrol into liposomes in order to promote its application in active food packaging. Response surface methodology was used to evaluate the effect of the concentration of the liposomal components on its characteristics. The optimum formulation for the preparation of liposomes with the highest encapsulation efficiency (59.0 ± 1.99%) was found to be 3000 μg mL^-1 of cholesterol and 4000 μg mL^-1 of carvacrol. Carvacrol reduced the polydispersity index and increased the zeta potential and the thermal stability of liposomes. Fourier-transform infrared spectroscopy indicated that the interaction of carvacrol with liposomes occurred probably through hydrogen-bonding. The incorporation into liposomes maintained the antibacterial effect of carvacrol, but when in the film, carvacrol liposomes were not effective against the microorganisms tested. Liposomes may offer a viable option for stabilizing carvacrol, however, more studies are necessary to enable its application in food packaging.

Green tea essential oil encapsulated chitosan nanoparticles-based radiopharmaceutical as a new trend for solid tumor theranosis

The existing study is embarked on investigating the antineoplastic activity of green tea essential oil (GTO) as a natural product. In this regard, GTO was encapsulated in cationic chitosan, nitrogenous-polysaccharide derived by partial deacetylation of chitin, nanoparticles (CS NPs) with entrapment efficiency (EE%) of 81.4 ± 5.7% and a mean particle-size of 30.7 ± 1.13 nm. Moreover, the cytotoxic effect of CS/GTO NPs was evaluated versus human liver (HepG-2), breast (MCF-7) and colon (HCT-116) cancer cell-lines and exhibited a positive impact when compared to bare CS NPs by 3, 2.3 and 1.7 fold for the three cell lines, respectively. More interestingly, CS/GTO NPs were complexed with technethium-99m (^99mTc) radionuclide. With a view to achieve a successful radiolabeling process, different parameters were optimized resulting in a radiolabeling efficiency (RE%) of 93.4 ± 1.2%. Radiopharmacokinetics of the radiolabeled NPs in healthy mice demonstrated a reticuloendothelial system (RES) evading and long blood circulation time up to 4 h. On the other hand, the biodistribution profile in solid tumor models showed 20.3 ± 2.1% localization and cancer cell targeting within just 30 min. On the whole, the reported results encourage the potential use of CS/GTO NPs as a side effect-free anticancer agent and its ^99mTc-analogue as a novel CS/GTO NPs-based diagnostic-radiopharmaceutical for cancer.

Shelf-life extension of pomegranate arils using chitosan nanoparticles loaded with Satureja hortensis essential oil

BACKGROUND

This study was conducted in two parts to improve the antimicrobial activity and stability of Satureja hortensis essential oil (SEO) and its impacts on the quality of pomegranate arils. In the first part, SEO was encapsulated by an ionic gelation technique into 142.2-267.7 nm chitosan nanoparticles (CSNPs). In the second part of the experiment, the CSNPs and CSNPs-SEO were applied to improve storability of pomegranate arils. Arils were dipped in water (control), CSNPs and CSNPs-SEO for 5 min. After superficial water removal, arils were packed into polystyrene boxes and stored at 5 °C for 18 days.

RESULTS

Based on spectrophotometry analysis, the encapsulation efficiency (EE) of SEO-loaded CSNPs (CSNPs-SEO) decreased from 26.57% to 7.41% and their loading capacity (LC) increased from 4.72% to 6.17%, respectively, upon increasing the initial SEO content from 0.125 to 0.5 g g^-1 of chitosan. Phytochemicals and water content were maintained, and microbial counts were reduced in the coated arils during storage. Total phenol and antioxidant activity decreased during storage. At the end of storage, the highest total phenol content (2980.0 mg gallic acid equivalents L^-1 ) was found in arils treated with CSNPs-SEO, whereas ascorbic acid content was maximal (6.32 mg L^-1 ) in arils treated with CSNPs. The encapsulation of savory essential oil in chitosan nanoparticles did not have undesirable effects in pomegranate arils.

CONCLUSION

Pre-storage treatment of pomegranate arils with CSNPs-SEO could be considered a beneficial treatment to better maintain the biochemical and sensorial quality during storage. © 2020 Society of Chemical Industry.

Polymeric nano- and microparticulate drug delivery systems for treatment of biofilms

Now-a-days healthcare systems face great challenges with antibiotic resistance and low efficacy of antibiotics when combating pathogenic bacteria and bacterial biofilms. Administration of an antibiotic in its free form is often ineffective due to lack of selectivity to the infectious site and breakdown of the antibiotic before it exerts its effect. Therefore, polymeric delivery systems, where the antibiotic is encapsulated into a formulation, have shown great promise, facilitating a high local drug concentration at the site of infection, a controlled drug release and less drug degradation. All this leads to improved therapeutic effects and fewer systemic side effects together with a lower risk of developing antibiotic resistance. Here, we review and provide a comprehensive overview of polymer-based nano- and microparticles as carriers for antimicrobial agents and their effect on eradicating bacterial biofilms. We have a main focus on polymeric particulates containing poly(lactic-co-glycolic acid), chitosan and polycaprolactone, but also strategies involving combinations of these polymers are included. Different production techniques are reviewed and important parameters for biofilm treatment are discussed such as drug loading capacity, control of drug release, influence of particle size and mobility in biofilms. Additionally, we reflect on other promising future strategies for combating biofilms such as lipid-polymer hybrid particles, enzymatic biofilm degradation, targeted/triggered antibiotic delivery and future alternatives to the conventional particles.

Nanoencapsulation of Essential Oils as Natural Food Antimicrobial Agents: An Overview

The global demand for safe and healthy food with minimal synthetic preservatives is continuously increasing. Natural food antimicrobials and especially essential oils (EOs) possess strong antimicrobial activities that could play a remarkable role as a novel source of food preservatives. Despite the excellent efficacy of EOs, they have not been widely used in the food industry due to some major intrinsic barriers, such as low water solubility, bioavailability, volatility, and stability in food systems. Recent advances in nanotechnology have the potential to address these existing barriers in order to use EOs as preservatives in food systems at low doses. Thus, in this review, we explored the latest advances of using natural actives as antimicrobial agents and the different strategies for nanoencapsulation used for this purpose. The state of the art concerning the antibacterial properties of EOs will be summarized, and the main latest applications of nanoencapsulated antimicrobial agents in food systems will be presented. This review should help researchers to better choose the most suitable encapsulation techniques and materials.

Chitosan Nanoparticles as a Promising Nanomaterial for Encapsulation of Pomegranate (Punica granatum L.) Peel Extract as a Natural Source of Antioxidants

The encapsulation of pomegranate peel extract (PPE) in chitosan nanoparticles (CSNPs) is an advantageous strategy to protect sensitive constituents of the extract. This study was aimed to develop PPE-loaded CSNPs and characterize their physical, structural morphology, antioxidant and antimicrobial properties. Spherical NPs were successfully synthesized with a mean diameter of 174–898 nm, a zeta potential (ZP) of +3 – +36 mV, an encapsulation efficiency (EE) of 26–70%, and a loading capacity (LC) of 14–21% depending on their loaded extract concentrations. Based on these results, CSNPs with chitosan:PPE ratio of 1:0.50 (w/w) exhibited good physical stability (ZP = 27 mV), the highest loading (LC = 20%) and desirable encapsulation efficiency (EE = 51%), and thus, selected as optimally loaded NPs. The FTIR analysis of PPE-CSNPs demonstrated no spectral changes indicating no possible chemical interaction between the PPE and CSNPs, which confirms that the PPE was physically entrapped within NPs. Moreover, FTIR spectra of pure PPE showed specific absorption bands (at 3293–3450 cm⁻¹) attributed to the incidence of phenolic compounds, such as tannic acid, ellagic acid and gallic acid. Total phenolic content (TPC) and antioxidant analysis of selected CSNPs revealed that the encapsulated NPs had significantly lower TPC and antioxidant activity than those of pure PPE, indicating that CSNPs successfully preserved PPE from rapid release during the measurements. Antibacterial tests indicated that pure PPE and PPE-loaded CSNPs effectively retarded the growth of Gram-positive S. aureus with a minimum inhibitory concentration (MIC) of 0.27 and 1.1 mg/mL, respectively. Whereas Gram-negative E. coli, due to its protective cell membrane, was not retarded by pure PPE and PPE-CSNPs at the MIC values tested in this study. Gas chromatography-mass spectroscopy analysis confirmed the incidence of various phytochemicals, including phenolic compounds, fatty acids, and furfurals, with possible antioxidant or antimicrobial properties. Overall, CSNPs can be regarded as suitable nanomaterials for the protection and controlled delivery of natural antioxidants/antimicrobials, such as PPE in food packaging applications.

Effect of green tea-loaded chitosan nanoparticles on leathery dentin microhardness

The purpose of this study was to assess the effect of a chitosan-based nanoformulation containing green tea on leathery (remaining) dentin subsurface microhardness. Size distribution, polydispersity index (PDI) and zeta potential (mV) of nanoformulations were previously determined by dynamic light scattering (DLS). Human dentin specimens were exposed to Streptococcus mutans for 14 d. Soft dentin were selectively removed by Er:YAG laser (n = 30) or bur (n = 30). Remaining dentin was biomodified with chitosan nanoparticles (Nchi, n = 10) or green tea-loaded chitosan nanoparticles (Gt + Nchi, n = 10) for 1 min. Control group (n = 10) did not receive any treatment. Subsurface microhardness (Knoop) was evaluated in hard (sound) and soft dentin, and then, in leathery dentin and after its biomodification, at depths of 30, 60 and 90 μm from the surface. Nchi reached an average size of ≤ 300 nm, PDI varied between 0.311 and 0.422, and zeta potential around + 30 mV. Gt + Nchi reached an average size of ≤ 350 nm, PDI < 0.45, and zeta potential around + 40 mV. Soft dentin showed significantly reduced microhardness at all depths (p > 0.05). The subsurface microhardness was independent of choice of excavation method (p > 0.05). At 30 µm from the surface, Gt + Nchi increased the leathery dentin microhardness compared to untreated group (p < 0.05). Nchi promoted intermediate values (p > 0.05). Both nanoformulations showed an average size less than 350 nm with nanoparticles of different sizes and stability along the 90-day period evaluated. Subsurface microhardness of bur-treated and laser-irradiated dentin was similar. At 30 µm, the biomodification with Gt + Nchi improved the microhardness of leathery dentin, independently of caries excavation method used.