Stability and loading properties of curcumin encapsulated in Chlorella vulgaris

A lipoprotein complex conjugated mesoporous silica as potent antibiotic adjuvant for synergistic antibacterial therapy of MRSA

Nowadays, the emergence of antibiotic-resistant bacteria has posed a global threat to public health. However, the deployment of alternative antibiotics is lagging far behind the fast evolving antibiotic resistance, which demands effective strategies to restore drug-resistance sensitivity to available antibiotics. Here, a well-known antitumor lipoprotein complex consisted of bovine α-lactalbumin and oleic acid (BAMLET) was electrostatically adsorbed on the surface of mesoporous silica nanomaterials (MSN), forming an antibiotic adjuvant to re-sensitize methicillin-resistant Staphylococcus aureus (MRSA) to aminoglycoside antibiotics. It was found MSN of distinctive particle size may cause conformational changes of bound lipoprotein complex affecting the bactericidal performance of formed BAMLET@MSN conjugates (BMSN). Moreover, MSN was loaded with curcumin to endow obtained BMSN improved bioavailability and antioxidant capacity. The mechanistic studies revealed that antibacterial activities of BMSN originated from bacterial cell membrane disruption and biofilm inhibition, which promoted antibiotic entry and restored antibiotic bactericidal efficacy in the cell. Finally, transcriptomic analysis of MRSA indicated that BMSN interfered with bacterial amino acid metabolism, carbohydrate synthesis, and ATP translocation in bacteria. Therefore, the constructed BMSN/curcumin as potent antibiotic adjuvant provided a manipulable nanoplatform to tackle the antibiotic resistance crisis.

Gum Arabic modified nano-nutriosomes for curcumin encapsulation: Characterization, influence on physicochemical, microstructural and microbial properties of integrated yogurt

As a hydrophobic compound, curcumin (Cur) requires modification to enhance stability in aqueous media, allowing its application in hydrophilic food matrix. This study aimed to improve the physicochemical stability of curcumin encapsulated in nano-nutriosomes (NU) decorated with gum Arabic (GA) polymer and their incorporation influence on the yogurt (Ygr) properties during 21 days of cold storage. The novel NU were nanosized (< 200 nm), with high encapsulation efficiency >90 % for Cur, spherical in shape, with an acceptable PDI < 0.3. The GA-Cur-NU significantly (p < 0.05) improved the Cur stability under thermal, pH and ionic conditions, as well as controlling the in vitro Cur release in PBS and different food simulants, confirming the improving effect of GA for better Cur stability. However, due to NU dispersion commercializing challenges in food, freeze-drying was employed to facilitate its application. Interestingly, The Cur was highly protected in freeze-dried FZD GA-Cur-NU with an encapsulation efficiency of 97.35 % compared to FZD Cur-NU 93.68 %. The yogurt gel network was strengthened after Cur-NU and GA-Cur-NU addition, improving the physicochemical properties, water holding capacity, color, texture, microstructure and LAB count of yogurt. Overall, the GA-coated NU could be a nano-carrier for Cur encapsulation and controlled delivery.

Protein Nanospheres and Nanofibers Prepared by Ice-Templating for the Controlled Release of Hydrophobic Drugs

Protein scaffolds play a vital role in drug delivery systems. However, few research studies have been focused on loading hydrophobic drugs on protein scaffolds in biomedical fields. Here, we report on the development of protein microspheres and nanofibers by a simple ice-templating approach and their use as scaffolds for the controlled release of hydrophobic drugs, with bovine serum albumin (BSA) as the model protein and curcumin as the model hydrophobic drug. The BSA scaffolds display the unique nanofibrous and microspherical structures. This is a surprising discovery because there has been no report on the formation of microspheres via simple ice-templating of solutions or suspensions. To further understand the formation of microspheres by this approach, lysozyme, papain, and their composites with BSA are also studied. It is speculated that nanoparticles are first formed in aqueous BSA solution, attributed to the overlapping of hydration layers and autoassembly of inner hydrophobic cores of BSA globular molecules. Nanoprecipitation and soaking evaporation approaches are then used to load curcumin into the BSA scaffolds, followed by cross-linking with glutaraldehyde vapor to improve stability in an aqueous medium. The controlled release of curcumin is demonstrated, paving the way for various hydrophobic drugs loaded into this biodegradable and nonimmunogenic protein scaffold for potential treatments of diverse diseases.

Encapsulation of polyketide colorants in chitosan and maltodextrin microparticles

This study aimed to encapsulate Talaromyces amestolkiae colorants in maltodextrin and chitosan microparticles using the spraydrying technique and to evaluate the biopolymers' capacities to protect the fungal colorant against temperature (65 °C) and extreme pH (2.0 and 13.0). The compact microparticles exhibited smooth or indented surfaces with internal diameters ranging between 2.58-4.69 μm and ζ ~ -26 mV. The encapsulation efficiencies were 86 % and 56 % for chitosan and maltodextrin microparticles, respectively. The shifted endothermic peaks of the free colorants indicated their physical stabilization into microparticles. The encapsulated colorants retained most of their absorbance (compared to the 0 h) even after 25 days at 65 °C. Contrary, the free colorant presented almost no absorbance after 1 day under the same conditions. Colorants in chitosan and maltodextrin matrices also partially maintained their colorimetric and fluorometric properties at acidic pH. However, only maltodextrin improved the resistance of the red colorant to alkaline environments. For the first time, the potential of polysaccharide-based microparticles to preserve polyketide colorants was demonstrated using 3D fluorescence. Therefore, this study demonstrated an alternative in developing functional products with natural color additives.

Examining the wound healing potential of curcumin-infused electrospun nanofibers from polyglutamic acid and gum arabic

Advancements in medicine have led to continuous enhancements and innovations in wound dressing materials, making them pivotal in medical care. We used natural biological macromolecules, γ-polyglutamic acid and gum arabic as primary raw materials to create nanofibers laden with curcumin by blending electrostatic spinning technology in the current investigation. These nanofibers were meticulously characterized using fluorescence microscopy, scanning electron microscopy, Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and X-ray diffraction (XRD). Our comprehensive analyses confirmed the successful encapsulation of curcumin within the nanofiber carrier and it has uniform diameter, good water absorption and mechanical properties. Subsequently, we evaluated the antimicrobial effects of these curcumin-loaded nanofibers against Staphylococcus aureus through an oscillating flask method. We created a mouse model with acute full-thickness skin defects to further investigate the wound healing potential. We conducted various biochemical assays to elucidate the mechanism of action. The results revealed that curcumin nanofibers profoundly impacted wound healing. They bolstered the expression of TGF-β1 and VEGF and reduced the expression of inflammatory factors, leading to an accelerated re-epithelialization process, enhanced wound contraction, and increased regeneration of new blood vessels and hair follicles. Furthermore, these nanofibers positively influenced the proportion of three different collagen types. This comprehensive study underscores the remarkable potential of curcumin-loaded nanofibers to facilitate wound healing and lays a robust experimental foundation for developing innovative, natural product-based wound dressings.

Sonoprocessing enhances the stabilization of fisetin by encapsulation in Saccharomyces cerevisiae cells

The objective of this study was to investigate for the first time the role of S. cerevisiae natural barriers and endogenous cytoplasmatic bodies on the stabilization of fisetin encapsulated via sonoprocessing coupled to freeze-drying (FD) or spray drying (SD). Both protocols of encapsulation improved the resistance of fisetin against thermal treatments (between 60 and 150 °C) and photochemical-induced deterioration (light exposition for 60 days) compared to non-encapsulated fisetin (antioxidant activity retention of approximately 55% and 90%, respectively). When stored under constant relative humidity (from 32.8 to 90%) for 60 days, yeast carriers improved the half-life time of fisetin by up to 4-fold. Spray dried particles were smaller (4.9 μm) and showed higher fisetin release after simulated gastrointestinal digestion (55.7%) when compared to FD. Freeze-dried particles, in turn, tended to agglomerate more than SD (zeta potential -19.7 mV), resulting in reduced loading features (6.3 mg/g) and less efficient protection of fisetin to heat, photo, and moisture-induced deterioration. Overall, spray-dried sonoprocessed fisetin capsules are an efficient way to preserve fisetin against harsh conditions. Altogether, this report shows that sonoprocessing coupled to drying is an efficient, creative, and straightforward route to protect and deliver lipophilic fisetin using yeast capsules for food applications.

Microencapsulation of Propolis and Honey Using Mixtures of Maltodextrin/Tara Gum and Modified Native Potato Starch/Tara Gum

Ethanolic extracts of propolis and bee honey contain substances beneficial to human health. Mixtures of wall materials were compared in spray-drying microencapsulation of ethanolic extracts of propolis and bee honey rich in bioactive compounds. Maltodextrin and tara gum were used to obtain microencapsulates A, and modified native potato starch and tara gum were used for microencapsulates B. High values of phenolic compounds, flavonoids, and antioxidant capacity were obtained in microcapsules A and B, and the results obtained in terms of encapsulation efficiency, yield, hygroscopicity, solubility, moisture, Aw, bulk density, and color were typical of the spray-drying process. On the other hand, spherical and elliptical microparticles of sizes between 7.83 and 53.7 µm with light and medium stability were observed. Thermogravimetric properties were similar in both microencapsulates; total organic carbon, SEM-EDS, and FTIR analyses corroborated the encapsulation. X-ray diffractogram exhibited amorphous structures, and the release kinetics of phenolic compounds presented high values from 8.13 to 12.58 mg GAE/g between 7 and 13 h. Finally, modified potato starch is a better encapsulant than maltodextrin because it has better core protection and controlled release of the encapsulated bioactive compounds.

Geotrichum candidum arthrospore cell wall particles as a novel carrier for curcumin encapsulation

We report for the first time that curcumin is successfully encapsulated into a new natural pre-formed carrier, which was derived from arthrospore cell wall particles (APs) of probiotic Geotrichum candidum LG-8 and mainly composed of beta-1,4-glucan. Vacuum infusion process was used for efficient encapsulation of curcumin. The results showed that the encapsulation efficiency and yield of APs were 36.5 ± 0.9 % and 730.6 ± 26.5 μg/g (wet basis), respectively. Compared with the other probiotic carriers such as Saccharomyces cerevisiae, it could more effectively maintain the antioxidant property and storage capacity of curcumin under high temperature conditions. Simulated digestion was conducted to study in vitro release of curcumin encapsulated in APs, and showed a maximum bioaccessibility of 65.6 ± 3.8 %. In view of low-cost culture method, simple encapsulation process and high encapsulation capacity, G. candidum arthrospores as new natural encapsulation carriers have potential superiority in the practical application in food industry.

Obtaining and Characterizing Andean Multi-Floral Propolis Nanoencapsulates in Polymeric Matrices

Propolis is a substance with significant anti-inflammatory, anticancer, and antiviral activity, which could be used more efficiently at the nano level as an additive in the food industry. The aim was to obtain and characterize nanoencapsulated multi-floral propolis from the agro-ecological region of Apurimac, Peru. For nanoencapsulation, 5% ethanolic extracts propolis with 0.3% gum arabic and 30% maltodextrin were prepared. Then, the mixtures were dried by nano spraying at 120 °C using the smallest nebulizer. The flavonoid content was between 1.81 and 6.66 mg quercetin/g, the phenolic compounds were between 1.76 and 6.13 mg GAE/g, and a high antioxidant capacity was observed. The results of moisture, water activity, bulk density, color, hygroscopicity, solubility, yield, and encapsulation efficiency were typical of the nano spray drying process. The total organic carbon content was around 24%, heterogeneous spherical particles were observed at nanometer level (between 11.1 and 562.6 nm), with different behaviors in colloidal solution, the thermal gravimetric properties were similar in all the encapsulates, the FTIR and EDS analysis confirmed the encapsulation and the X-ray diffraction showed amorphous characteristics in the obtained material; stability and phenolic compound release studies indicated high values of 8.25–12.50 mg GAE/g between 8 and 12 h, the principal component analysis confirmed that the flora, altitude, and climate of the propolis location influenced the content of bioactive compounds, antioxidant capacity, and other properties studied. The nanoencapsulate from the district of Huancaray was the one with the best results, allowing its future use as a natural ingredient in functional foods. Nevertheless, technological, sensory, and economic studies should still be carried out.

Sonoprocessing is an effective strategy to encapsulate fisetin into Saccharomyces cerevisiae cells

The encapsulation of fisetin into S. cerevisiae cells through sonoporation coupled with drying is reported for the first time in the literature. To establish the best conditions to maximize the amount of internalized fisetin, the cell density (5-10% w/v), fisetin concentration (1-3 mg/mL), acoustic energy density (0-333.3 W/L), and drying method (freeze-drying and spray drying) were analyzed through a Box-Behnken experimental design (BBD) coupled with response surface methodology (RSM). Higher encapsulation efficiency (EE) was achieved with a cell density of 10% w/v, while fisetin concentration of 3 mg/mL favored the encapsulation yield (EY) and antioxidant activity (AA). Higher EE (67.7%), EY (25.7 mg/g), and AA (90%) were registered when an acoustic density of 333.3 W/L was used. Furthermore, both drying protocols promoted fisetin encapsulation, but through spray drying, the EE, EY, and AA were 11.5%, 11.1%, and 26.6% higher than via freeze-drying, respectively. This work proved that fully filled biocapsules were produced through sonoprocessing, and their morphology was influenced by the acoustic energy and drying process. Overall, these results open new perspectives for the application of sonoprocessing-assisted encapsulation, paving the way for developing innovative yeast-based delivery systems for lipophilic compounds such as fisetin. KEY POINTS: • Sonoprocessing improves the encapsulation of fisetin into S. cerevisiae cells • Spray drying promotes fisetin loading into yeasts' intracellular space and cavities • Fisetin binding with yeast extracellular agents are favored by freeze-drying.

Effects of C/N ratio on the growth and protein accumulation of heterotrophic Chlorella in broken rice hydrolysate

BACKGROUND

Microalgae protein is considered as a sustainable alternative to animal protein in the future. Using waste for microalgal culture can upgrade low-value raw materials into high-value products, helping to offset the cost of microalgal protein production. In this study we explored the feasibility of using microalgae heterotrophic fermentation to convert broken rice hydrolysate (BRH) into protein.

RESULTS

The results showed that the increase of BRH supplemental ratio was beneficial to the increase of biomass production but not beneficial to the increase of intracellular protein content. To further improve protein production, the effect of C/N ratio on intracellular protein accumulation was studied. It was found that low C/N ratio was beneficial to the synthesis of glutamate in microalgae cells, which in turn promoted the anabolism of other amino acids and further the protein. When the C/N ratio was 12:1, the biomass productivity and protein content could reach a higher level, which were 0.90 g/L/day and 61.56%, respectively. The obtained Chlorella vulgaris biomass was rich in essential amino acids (41.80%), the essential amino acid index was as high as 89.07, and the lysine content could reach up to 4.05 g/100 g.

CONCLUSIONS

This study provides a theoretical basis and guidance for using Chlorella vulgaris as an industrial fermentation platform to convert broken rice into products with high nutritional value.

Ultrasound-assisted encapsulation of curcumin and fisetin into Saccharomyces cerevisiae cells: a multistage batch process protocol

Some of the challenges of yeast encapsulation protocols are low phytochemical internalization rates and limited intracellular compartment of yeasts. This study uses an ultrasound-assisted batch encapsulation (UABE) protocol to optimize the encapsulation of curcumin and fisetin by recovering non-encapsulated biomaterial and further incorporating it into non-loaded yeasts in three encapsulation stages (1ES, 2ES, and 3ES). The effect of selected acoustic energies (166.7 and 333.3 W L^-1 ) on the encapsulation efficiency (EE), yield (EY), and antioxidant activity retention were evaluated, and then, compared with a control process (without ultrasound treatment). Compared to the control, enhanced EEs were achieved for both curcumin (10.9% control to 58.5% UABE) and fisetin (18.6% control to 76.6% UABE) after 3ES and the use of 333.3 W L^-1 . Similarly, the yeast maximum loading capacity was improved from 6.6 to 13.4 mg g^-1 for curcumin; and from 11.1 to 26.4 mg g^-1 for fisetin after UABE protocol. The antioxidant activity of produced biocapsules was positively correlated with the bioactive loaded content of yeasts when ultrasound treatment was applied. Overall, results from this study provide valuable information regarding UABE processes, and moreover, bring new and creative perspectives for the ultrasound technology in the food industry.

Efficient encapsulation of curcumin into spent brewer's yeast using a pH-driven method

Curcumin (CUR) was encapsulated into yeast cells (YCs) through a pH-driven method with a 5.04-fold increase in loading capacity and a 43.63-fold reduction in incubation time compared to the conventional diffusion method. Optimal encapsulation was obtained when the mass ratio of CUR to YCs was 0.1, and the loading capacity and encapsulation efficiency were 8.07% and 80.66%, respectively. Encapsulation of CUR into YCs was confirmed by fluorescence microscopy, differential scanning calorimetry, and thermogravimetric analysis. Fourier transform infrared spectroscopy and X-ray diffraction further demonstrated that the encapsulated CUR was interacted with mannoprotein and β-glucan of the cell wall network through hydrophobic interaction and hydrogen bond in amorphous state. The in vitro bioaccessibility of YCs-loaded CUR was significantly increased by 6.05-fold. The enhanced encapsulation efficiency and rapid encapsulation process proposed in this study could facilitate YCs-based microcarriers to encapsulate bioactive substances with higher bioaccessibility.

pH-Responsive Eco-Friendly Chitosan–Chlorella Hydrogel Beads for Water Retention and Controlled Release of Humic Acid

For improving the mechanical strength of controlled release fertilizer (CRF) hydrogels, a novel material of Chlorella was employed as a bio-based filler to prepare chitosan–chlorella hydrogel beads with physical crosslink method. Here, the synthesis mechanism was investigated, and the chitosan–chlorella hydrogel beads exhibited enhanced mechanical stability under centrifugation and sonication than pure chitosan hydrogel beads. Chlorella brought more abundant functional groups to original chitosan hydrogel, hence, chitosan–chlorella hydrogel beads represented greater sensitivity and controllable response to external factors including pH, salt solution, temperature. In distilled water, the hydrogel beads with 40 wt% Chlorella reached the largest water absorption ratio of 42.92 g/g. Moreover, the mechanism and kinetics process of swelling behavior of the chitosan–chlorella hydrogel beads were evaluated, and the loading and releasing of humic acid by the hydrogel beads as a carrier material were pH-dependent and adjustable, which exhibit the potential of chitosan–chlorella hydrogel beads in the field of controlled release carrier biomaterials.

Carrier-Free Small Molecular Self-Assembly Based on Berberine and Curcumin Incorporated in Submicron Particles for Improving Antimicrobial Activity

Nanocarrier-based pesticide formulations have been severely restricted in agriculture practices due to their high-cost preparation process, poor loading capacity, and toxicity issues. To overcome these issues, carrier-free small molecular self-assembled submicron particles (SMPs) with an improved photoactivated antimicrobial activity based on two natural microbicides berberine hydrochloride (BBR) and curcumin (CM) are constructed by noncovalent interactions through a simple and fast preparation process (solvent exchange method) without using any adjuvant. The results show that the optimized molar ratio of BBR to CM is 2:1 at pH 5 and 25 °C in an aqueous solution for the formation of B-C SMPs. The obtained B-C SMPs exhibit excellent physicochemical properties, such as uniform morphology (407 nm), low polydispersity index (0.283), and strong ζ-potential (+24.4 mV). The antibacterial activities of B-C SMPs against Pseudomonas syringae pv. lachrymans, Clavibater michiganensis subsp. Michiganensis, and Sclerotinia sclerotiorum are 4, 2, and 1.5 times that of B + C MIX, respectively, suggesting a synergistic antimicrobial activity based on BBR and CM incorporation in the submicron particles. The genotoxicity evaluation results show that the self-assembled B-C SMPs are harmless to plant cells. Therefore, due to rational utilization of natural resources (natural microbicides, sunlight, and oxygen), carrier-free small molecular self-assembled B-C SMPs with synergistic photoactivated antimicrobial activity developed by a simple and fast preparation process would have great potential for sustainable plant disease management.

Encapsulation, protection, and delivery of curcumin using succinylated-cyclodextrin systems with strong resistance to environmental and physiological stimuli

Curcumin is commonly used as a nutraceutical in functional food and beverage formulations because of various biological activities. Typically, curcumin is encapsulated in edible nanoparticles or microparticles to improve its water-dispersibility, chemical stability, and bioavailability. In this study, a succinic acid-modified cyclodextrin (SACD) was fabricated and applied as a carrier for curcumin. Curcumin-loaded SACD (Cur-SACD) with a molar ratio of 1:1 and an encapsulation efficiency > 80% was formed spontaneously basing on hydrogen bonding between the aromatic ring of the curcumin and the hydrophobic cavity of the SACD. Cur-SACD exhibited excellent stability against long-time storage, UV-irradiation, and pasteurization, as well as against physiological conditions including body temperature, physiological salt concentrations, stomach and intestinal pH. This study suggests that Cur-SACD systems may be suitable for increasing the water-dispersibility, stability, and bioavailability of hydrophobic compounds intended for oral administration, such as those used in the food, supplement, and pharmaceutical industries.

Mechanism of enhancing the water-solubility and stability of curcumin by using self-assembled cod protein nanoparticles at an alkaline pH

Curcumin (Cur) is a bioactive phytochemical which is claimed to have several health-promoting benefits, whose applications are challenging due to its poor water-solubility, chemical instability, and low bioavailability. In this research, Cur was encapsulated in the cod protein (CP) using a pH-driven method to enhance its solubility and stability. The physicochemical and structural properties of cod protein-curcumin nanoparticles (CP-Cur) formed were characterized. Fluorescence spectroscopy (FL), ultraviolet spectroscopy (UV), circular dichroism (CD), and dynamic light scattering (DLS) results collectively suggest that the protein originally with a molten-globule state refolded into a more ordered structure after neutralization, during which Cur was incorporated. Fluorescence quenching and isothermal titration calorimetry (ITC) further showed that the CP/Cur binding was mainly driven by hydrophobic interactions, resulting in static fluorescence quenching and energy release. Up to 99.50% of Cur was loaded in the CP delivery system. Furthermore, the thermal stability and photostability of Cur were greatly improved due to the protection of the protein. The present study proved that cod protein could be a great potential edible carrier for encapsulating curcumin.

Melt Electrospinning of Polymers: Blends, Nanocomposites, Additives and Applications

Melt electrospinning has been developed in the last decade as an eco-friendly and solvent-free process to fill the gap between the advantages of solution electrospinning and the need of a cost-effective technique for industrial applications. Although the benefits of using melt electrospinning compared to solution electrospinning are impressive, there are still challenges that should be solved. These mainly concern to the improvement of polymer melt processability with reduction of polymer degradation and enhancement of fiber stability; and the achievement of a good control over the fiber size and especially for the production of large scale ultrafine fibers. This review is focused in the last research works discussing the different melt processing techniques, the most significant melt processing parameters, the incorporation of different additives (e.g., viscosity and conductivity modifiers), the development of polymer blends and nanocomposites, the new potential applications and the use of drug-loaded melt electrospun scaffolds for biomedical applications.

Microalgae Encapsulation Systems for Food, Pharmaceutical and Cosmetics Applications

Microalgae are microorganisms with a singular biochemical composition, including several biologically active compounds with proven pharmacological activities, such as anticancer, antioxidant and anti-inflammatory activities, among others. These properties make microalgae an interesting natural resource to be used as a functional ingredient, as well as in the prevention and treatment of diseases, or cosmetic formulations. Nevertheless, natural bioactives often possess inherent chemical instability and/or poor solubility, which are usually associated with low bioavailability. As such, their industrial potential as a health-promoting substance might be severely compromised. In this context, encapsulation systems are considered as a promising and emerging strategy to overcome these shortcomings due to the presence of a surrounding protective layer. Diverse systems have already been reported in the literature for natural bioactives, where some of them have been successfully applied to microalgae compounds. Therefore, this review focuses on exploring encapsulation systems for microalgae biomass, their extracts, or purified bioactives for food, pharmaceutical, and cosmetic purposes. Moreover, this work also covers the most common encapsulation techniques and types of coating materials used, along with the main findings regarding the beneficial effects of these systems.

Encapsulation of ellagic acid from pomegranate peels in microalgae optimized by response surface methodology and an investigation of its controlled released under simulated gastrointestinal studies

Ellagic acid (EA), a naturally occurring bioactive phenolic compound largely found in pomegranate, exhibits significant health benefits due to its antioxidant, antimutagenic, and even anticancerogenic properties. The present work aimed to microencapsulate EA extracted from pomegranate peels. To improve the stability of EA, microencapsulation was applied with Spirulina as a coating material. For this purpose, ethanolic extracts obtained from pomegranate peels were used for microencapsulation. Response surface methodology combined with a three-level, three-variable Box-Behnken design (BBD) was applied to obtain optimum microencapsulation. The microparticles obtained under the optimized encapsulation conditions were further characterized by FT-IR and SEM. The results confirmed the encapsulation of EA in Spirulina cells. Then, the optimum microparticles were used in an in vitro release study. The results of the in vitro digestion with simulated gastrointestinal fluids could help to determine the content and biological activity of EA. In this study, the effect of encapsulation on the release properties of EA during simulated gastrointestinal digestion was also evaluated. HPLC-DAD analysis and the Folin-Ciocalteu and ABTS methods were helpful for characterization of EA in the simulated fluids. The release profile of EA indicated that in simulated intestinal fluid, the release was faster than that in gastric fluid. PRACTICAL APPLICATION: This study describes the microencapsulation of ethanolic extracts of pomegranate peel (PP) in Spirulina. This application has been performed to improve the stability and bioavailability of EA in the extracts. Optimum microencapsulation was obtained by response surface methodology with BBD. After the characterization of the obtained optimum Spirulina/EA mixture by FT-IR and SEM, an in vitro release study was conducted for stability research. The results will guide other researchers working on the determination of the content and biological activity of EA and on optimizing the microencapsulation process.

The nanoencapsulation of curcuminoids extracted from Curcuma longa L. and an evaluation of their cytotoxic, enzymatic, antioxidant and anti-inflammatory activities

Curcumin, bisdemethoxycurcumin and demethoxycurcumin are known for their bioactivity.

Graphene Oxide Functional Nanohybrids with Magnetic Nanoparticles for Improved Vectorization of Doxorubicin to Neuroblastoma Cells

With the aim to obtain a site-specific doxorubicin (DOX) delivery in neuroblastoma SH-SY5Y cells, we designed an hybrid nanocarrier combining graphene oxide (GO) and magnetic iron oxide nanoparticles (MNPs), acting as core elements, and a curcumin⁻human serum albumin conjugate as functional coating. The nanohybrid, synthesized by redox reaction between the MNPs@GO system and albumin bioconjugate, consisted of MNPs@GO nanosheets homogeneously coated by the bioconjugate as verified by SEM investigations. Drug release experiments showed a pH-responsive behavior with higher release amounts in acidic (45% at pH 5.0) vs. neutral (28% at pH 7.4) environments. Cell internalization studies proved the presence of nanohybrid inside SH-SY5Y cytoplasm. The improved efficacy obtained in viability assays is given by the synergy of functional coating and MNPs constituting the nanohybrids: while curcumin moieties were able to keep low DOX cytotoxicity levels (at concentrations of 0.44⁻0.88 µM), the presence of MNPs allowed remote actuation on the nanohybrid by a magnetic field, increasing the dose delivered at the target site.

Evidence of curcumin and curcumin analogue effects in skin diseases: A narrative review

Curcumin, a natural polyphenolic and yellow pigment obtained from the spice turmeric, has strong antioxidative, anti-inflammatory, and antibacterial properties. Due to these properties, curcumin has been used as a remedy for the prevention and treatment of skin aging and disorders such as psoriasis, infection, acne, skin inflammation, and skin cancer. Curcumin has protective effects against skin damage caused by chronic ultraviolet B radiation. One of the challenges in maximizing the therapeutic potential of curcumin is its low bioavailability, limited aqueous solubility, and chemical instability. In this regard, the present review is focused on recent studies concerning the use of curcumin for the treatment of skin diseases, as well as offering new and efficient strategies to optimize its pharmacokinetic profile and increase its bioavailability.

Co-encapsulation of curcumin and resveratrol into novel nutraceutical hyalurosomes nano-food delivery system based on oligo-hyaluronic acid-curcumin polymer

In this work, in order to enhance the stability, bioavailability and antioxidant activity of insoluble antioxidants used into juice, yoghourt and nutritional supplements, the oligo-hyalurosomes nano-delivery system (CRHs) based on oligo-hyaluronic acid -curcumin (oHC) polymer loaded curcumin(Cur) and resveratrol (Res) was fabricated with new nanotechnolgy. The rosy biodegradable amphiphilic oHC polymer was successfully synthesized and used to fabricate the hyalurosomes containing both Cur and Res, called CRHs. The CRHs can spontaneously self-assemble into nano-sized spherical shape of average particle size 134.5±5.1nm and Zeta potential -29.4±1.2 at pH 7.4 PBS conditions. In vitro gastrointestinal release test showed a perfect stability and outstanding sustained release character. Moreover, compared to the single formulations and liposomes, CRHs showed a dose-dependent manner with a higher radical scavenging activity. Therefore, the novel CRHs nano-food manifested the hopeful properties for the new effective gastrointestinal formulation and promising new nano-food delivery system in the use of juice, yoghourt and nutritional supplements.