Encapsulation Capacity Research Articles

Fabrication of Sacha Inchi Oil-Loaded Microcapsules Employing Natural-Templated Lycopodium clavatum Spores and Their Pressure-Stimuli Release Behavior.

Polymeric particles have attracted vast attention for use in various fields, especially as drug carriers and cosmetics, due to their excellent ability to protect active ingredients from the environment until reaching a target site. However, these materials are commonly produced from conventional synthetic polymers, which impose adverse effects on the environment due to their non-degradable nature, leading to waste accumulation and pollution in the ecosystem. This work aims to utilize naturally occurring Lycopodium clavatum spores to encapsulate sacha inchi oil (SIO), which contains active compounds with antioxidant activity, by applying a facile passive loading/solvent diffusion-assisted method. Sequential chemical treatments by acetone, potassium hydroxide, and phosphoric acid were employed to remove native biomolecules from the spores before encapsulation effectively. These are mild and facile processes compared to other synthetic polymeric materials. Scanning electron microscopy and Fourier-transform infrared spectroscopy revealed the clean, intact, and ready-to-use microcapsule spores. After the treatments, the structural morphology of the treated spores remained significantly unchanged compared to the untreated counterparts. With an oil/spore ratio of 0.75:1.00 (SIO@spore-0.75), high encapsulation efficiency and capacity loading values of 51.2 and 29.3%, respectively, were obtained. Using antioxidant assay (DPPH), the IC50 of SIO@spore-0.75 was 5.25 ± 3.04 mg/mL, similar to that of pure SIO (5.51 ± 0.31 mg/mL). Under pressure stimuli (1990 N/cm3, equivalent to a gentle press), a high amount of SIO was released (82%) from the microcapsules within 3 min. At an incubation time of 24 h, cytotoxicity tests showed a high cell viability of 88% at the highest concentration of the microcapsules (10 mg/mL), reflecting biocompatibility. The prepared microcapsules have a high potential for cosmetic applications, especially as functional scrub beads in facial washing products.

Phosphorylated walnut protein/chitosan nanocomplexes as promising carriers for encapsulation of caffeic acid phenethyl ester.

Walnut proteins have poor solubility and dispersity under acidic pH conditions, which limits their application in acidic beverages and foods. The present study aimed to fabricate stable nanocomplexes between phosphorylated walnut protein (PWPI) and chitosan (CS) at acidic pH and investigate the encapsulation capacity of the complexes. PWPI/CS nanocomplexes prepared at a mass ratio of 2:1 showed small Z-average sizes (approximately 285 nm at pH 5.5 and 222 nm at pH 3.5) with a narrow particle distribution (polydispersity index < 0.3). Caffeic acid phenethyl ester (CAPE) can be effectively encapsulated into PWPI/CS with improved solubility. Circular dichroism analysis indicated that PWPI/CS and CAPE-loaded PWPI/CS (PWPI/CS-CAPE) had a reduced α-helical content and increased β-sheet content. Fourier transform infrared spectroscopy analysis further identified the different driving forces for the complexation of PWPI and CS at pH 3.5 and 5.5 and confirmed the successful encapsulation of CAPE. Rheological results revealed that the PWPI/CS and PWPI/CS-CAPE formed at pH 3.5 (PWPI/CS-CAPE-3.5) had a higher apparent viscosity and better viscoelasticity than the complexes formed at pH 5.5. PWPI/CS-CAPE-3.5 also showed good stability under heat treatment, salt treatment, and long-term storage. Moreover, PWPI/CS-CAPE complexes showed controlled release of CAPE. PWPI/CS nanocomplexes prepared at acidic pH were stable and promising carriers for CAPE, which would expand the application of walnut proteins in the food industry. This article is protected by copyright. All rights reserved.

Constitution and reconstitution of microcapsules with high diacylglycerol oil loading capacity based on whey protein isolate / octenyl succinic anhydride starch/ inulin matrix

The aim of this study was to constitute microcapsule systems with high oil loading capacity by octenyl succinic anhydride (OSA) starch, whey protein isolate (WPI) and inulin (IN) substrates to provide a new method for encapsulating diacylglycerol oil. Specifically, this study characterizes the physicochemical properties and reconstitution capacity of highly oil loading diacylglycerol microcapsules by comparing the wall encapsulation capacity of the binary wall system OSA-IN, WPI-IN and the ternary wall system WPI-OSA (1:9, 5:5, 9:1)-IN for diacylglycerol oil. It was found that WPI-OSA (5:5)-IN significantly improved the water solubility of microcapsules (86.11 %) compared to OSA-IN microcapsules, and the addition of WPI made the surface of microcapsules smoother and increased the thermal stability and solubility of microcapsules; the addition of OSA enhanced the wettability of microcapsules compared to WPI-IN. In addition, WPI-OSA (5:5)-IN microcapsules have the highest encapsulation efficiency (96.03 %), high emulsion stability after reconstitution, and the smallest droplet size (212.83 nm) after 28 d. Therefore, the WPI-OSA-IN composite system is suitable for the production of highly oil-loaded microencapsulated systems with excellent reconstitution ability to expand the application of diacylglycerol oil.

On how zeolitic imidazolate framework-8 reduces silver ion release and affects cytotoxicity and antimicrobial properties of AgNPs@ZIF8 nanocomposite

For the first time, this study compared three types of Ag-doped ZIF-8 nanocomposites (AgNPs@ZIF-8(α), AgNPs@ZIF-8(β), and APTES-functionalized AgNPs@ZIF-8(γ)), besides ZIF-8 and APTES@ZIF-8. The composites were characterized in terms of morphology and crystalline structure, encapsulation capacity, capability to keep silver, antibacterial activity against E. coli and S. aureus, and cytotoxicity to human skin fibroblast (HSK) cell line. TEM analysis showed spherical dots of AgNPs (< 10 nm) on the surface or in matrix of ZIF-8 particles, and also their XPS spectra displayed two peaks corresponding to Ag 3d3/2 and Ag 3d5/2. FTIR analysis confirmed a successful chemical interaction between APTES and ZIF-8 in AgNPs@ZIF-8(γ). All of the nanocomposites displayed a combination of microporosity (<2 nm) and mesoporosity (2–50 nm) structures. BET analysis showed a specific surface area of 1718.5 m2/g for ZIF-8, whereas the amine-functionalized particles (i.e., APTES@ZIF-8 and AgNPs@ZIF-8(γ)) showed a decrease of about 1000 m2/g in the surface area and an increase of about 2 times in pore diameter. Different levels of silver were doped into the nanocomposites: AgNPs@ZIF-8(α), 7.04 mg/g; AgNPs@ZIF-8(γ), 27.17 mg/g; and AgNPs@ZIF-8(β), 38.91 mg/g. MTT test on HSK cells revealed IC50 values of 31.4–39 µg/ml for the three Ag-doped ZIF-8 and a higher IC50 (48.2 µg/ml) for ZIF-8. AgNPs@ZIF-8(β) and AgNPs@ZIF-8(γ) displayed MICs of 400 µg/ml and between 400 and 600 µg/ml against both E. coli and S. aureus, and the Ag-doped composites illustrated an Ag-loading content dependency to induce antibacterial activity. Taken together, the findings suggest that AgNPs@ZIF-8 nanocomposites could be introduced as a safer alternative for AgNPs or antibiotics to the health and biomedical industries.

Assessment of micro-crack self-healing performance of encapsulated bacteria in cement mortar

The improvement of strength and durability properties of concrete has been of great interest to researchers in the last two decades. Even though concrete is well known for its strength, there is always the possibility of cracks occurring due to various environmental conditions and loading. Sometimes these cracks may lead to corrosion of embedded reinforcement of structures if left unidentified. Even though there have been several solutions to rectify this problem, the addition of calcite precipitating microbes attracted the attention of researchers around the globe. The current research addressed this specific problem of healing cracks by encapsulating calcite precipitating bacteria into lightweight aggregate and replacing it with certain percentages of fine aggregate. The bacterial cells were encapsulated into expanded perlite, and a two-layer coating was done for better sealing performance to protect bacteria. The encapsulation capacity of the bacteria into the expanded perlite was found to be 6x108 cells/g. The cement mortar specimens were prepared by replacing fine aggregate with bacteria-encapsulated pellets in 10%, 15%, 20%, and 25%. To address the reduction in strength due to aggregate replacement was countered by adding nano silica into the mortar mixture in 5%, 8%, and 10%. The selected bacteria successfully healed a maximum crack width of 0.62 mm on the 28th day was confirmed visually by ImageJ analysis. The 20% aggregate replacement and 5% nano-silica blend was found to be optimum in terms of healing microcracks and compressive strength, respectively, in the prepared specimen. The efficiency of self-healing of bacteria and improving strength due to adding nano-silica was determined through the water permeability rate and compressive strength tests, respectively. The bacteria-precipitated calcite crystals at the crack region were also confirmed by observing under a field emission scanning electron microscope.

Bioorthogonal chemical imaging of solid lipid nanoparticles with minimal labeling by stimulated Raman scattering microscopy

AbstractSolid lipid nanoparticles (SLNs) are a state‐of‐the‐art lipid‐based pharmaceutical drug delivery system. Advantages of SLNs include high biocompatibility, low immunogenicity, superiority in drug encapsulation capacity, and improved colloidal stability. They became widely known in late 2020, as several COVID‐19 vaccines are built upon SLNs technology. Despite the increasing impact, the characterization methods of SLNs are currently very limited especially in biological environment, which hinders fundamental understanding of the delivery mechanism and contributes to relatively low success rate in clinical translations. Here, we present close‐to‐label‐free imaging of deuterated SLNs using the emerging stimulated Raman scattering (SRS) microscopy. The introduction of deuterium to lipid structure renders bioorthogonal chemical specificity. Notably, with this approach, we have achieved ultrahigh single‐particle sensitivity both in vitro and in vivo, even with particle counting ability. Our bioorthogonal chemical imaging modality by SRS microscopy can be generalized to visualize a wide spectrum of lipid‐based drug carriers with high spatiotemporal resolution, chemical specificity, and ultimate sensitivity. This work opens up ways to address critical questions in SLN drug delivery and could also facilitate innovations in lipid nanotechnology and clinical translations.Key points Direct imaging of lipid nanocarrier that is the basis of the COVID‐19 vaccines. Novel single‐particle imaging technique applied to nanomedicine. Frontier of nanomaterial, optical imaging, and molecular pharmacology.

Formulated chitosan-sodium tripolyphosphate nanoparticles for co-encapsulation of ellagic acid and anti-inflammatory peptide: characterization, stability and anti-inflammatory activity.

Chitosan (CS) and tripolyphosphate (TPP) can be combined in the development of a material with synergistic properties and promising potential for the conservation of food products. In this study, ellagic acid (EA) and anti-inflammatory peptide (FPL)-loaded CS nanoparticles (FPL/EA NPs) were prepared using the ionic gelation method and optimal preparation conditions were obtained through a single factor design. The synthesized nanoparticles (NPs) were characterized using a scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and differential scanning calorimetry (DSC). Nanoparticles were spherical, with an average size of 308.33 ± 4.61 nm, a polydispersity index (PDI) of 0.254, a zeta potential of +31.7 ± 0.08 mV, and a high encapsulation capacity (22.16 ± 0.79%). An in vitro release study showed that EA/FPL had a sustainable release from FPL/EA NPs. The stability of the FPL/EA NPs was evaluated for 90 days at 0, 25, and 37 °C. Significant anti-inflammatory activity of FPL/EA NPs was verified by nitric oxide (NO) and tumor necrosis factor-α (TNF-α) reduction. These characteristics support the use of CS nanoparticles to encapsulate EA and FPL and improve their bioactivity in food products. © 2023 Society of Chemical Industry.

Influence of Polycaprolactone Concentration and Solvent Type on the Dimensions and Morphology of Electrosprayed Particles.

Polycaprolactone (PCL) micro- and nanoparticles produced using the electrospraying technique present high drug encapsulation capacity, a controllable surface area, and a good cost-benefit ratio. PCL is also considered a non-toxic polymeric material with excellent biocompatibility and biodegradability. All these characteristics make PCL micro- and nanoparticles a promising material for tissue engineering regeneration, drug delivery, and surface modification in dentistry. In this study, PCL electrosprayed specimens were produced and analyzed to determine their morphology and size. Three PCL concentrations (2, 4, and 6 wt%) and three solvent types (chloroform (CF), dimethylformamide (DMF), and acetic acid (AA)) with various solvent mixtures ratios (1:1 CF/DMF, 3:1 CF/DMF, 100% CF, 1:1 AA/CF, 3:1 AA/CF, and 100% AA) were used while keeping the remaining electrospray parameters constant. SEM images followed by ImageJ analysis showed a change in the morphology and size of the particles among various tested groups. A two-way ANOVA demonstrated a statistically significant interaction (p < 0.001) between PCL concentration and solvents on the size of the particles. With the increase in the PCL concentration, an increase in the number of fibers was observed among all the groups. The morphology and dimensions of the electrosprayed particles, as well as the presence of fibers, were significantly dependent on the PCL concentration, choice of solvent, and solvent ratio.

Synthesis of Catalytic Microswimmers Based on Anisotropic Platinum Sorption on Melamine Barbiturate Supramolecular Structures

Herein, a straightforward synthesis approach for the formation of anisotropic microswimmers is proposed as an alternative to a top–down fabrication for asymmetric artificial swimmers. Melamine barbiturate (MBA)–self‐assembled supramolecular crystals are utilized as an asymmetric matrix for selective chemical platinum deposition. Surface functional groups of prevalent crystallographic planes for platinum sorption are presented by acidic sites of the assembly. The formed platinum catalytic layer is separated from the bulk MBA and investigated using X‐Ray photoelectron spectroscopy and scanning electron microscope energy‐dispersive X‐Ray spectroscopy analysis. Both methods confirm platinum adsorption and reduction of platinum ions during the deposition process. The MBA asymmetric swimmers show directional motion in a fuel environment, proved by the mean‐squared displacement study. Previously reported pH‐dependency and encapsulation capacity of MBA opens wide opportunities for functional materials formation.

Nanocapsules of ZnO Nanorods and Geraniol as a Novel Mean for the Effective Control of Botrytis cinerea in Tomato and Cucumber Plants.

Inorganic-based nanoparticle formulations of bioactive compounds are a promising nanoscale application that allow agrochemicals to be entrapped and/or encapsulated, enabling gradual and targeted delivery of their active ingredients. In this context, hydrophobic ZnO@OAm nanorods (NRs) were firstly synthesized and characterized via physicochemical techniques and then encapsulated within the biodegradable and biocompatible sodium dodecyl sulfate (SDS), either separately (ZnO NCs) or in combination with geraniol in the effective ratios of 1:1 (ZnOGer1 NCs), 1:2 (ZnOGer2 NCs), and 1:3 (ZnOGer2 NCs), respectively. The mean hydrodynamic size, polydispersity index (PDI), and ζ-potential of the nanocapsules were determined at different pH values. The efficiency of encapsulation (EE, %) and loading capacity (LC, %) of NCs were also determined. Pharmacokinetics of ZnOGer1 NCs and ZnOGer2 NCs showed a sustainable release profile of geraniol over 96 h and a higher stability at 25 ± 0.5 °C rather than at 35 ± 0.5 °C. ZnOGer1 NCs, ZnOGer2 NCs and ZnO NCs were evaluated in vitro against B. cinerea, and EC50 values were calculated at 176 μg/mL, 150 μg/mL, and > 500 μg/mL, respectively. Subsequently, ZnOGer1 NCs and ZnOGer2 NCs were tested by foliar application on B. cinerea-inoculated tomato and cucumber plants, showing a significant reduction of disease severity. The foliar application of both NCs resulted in more effective inhibition of the pathogen in the infected cucumber plants as compared to the treatment with the chemical fungicide Luna Sensation SC. In contrast, tomato plants treated with ZnOGer2 NCs demonstrated a better inhibition of the disease as compared to the treatment with ZnOGer1 NCs and Luna. None of the treatments caused phytotoxic effects. These results support the potential for the use of the specific NCs as plant protection agents against B. cinerea in agriculture as an effective alternative to synthetic fungicides.

Stimuli-Responsive Cucurbit[n]uril-Based Supramolecular Nanocarriers for Delivery of Chemotherapeutics

Chemotherapeutics commonly exhibit low bioavailability and systemic adverse effects. Supramolecular nanovesicles, such as pillar[n]arenes, calix[n]arenes, cucurbit[n]urils (CBs), and cyclodextrins, have been introduced as promising nanocarriers due to their remarkable encapsulation capacity and ability to host hydro-philic/-phobic guest molecules. Additionally, such nanovesicles can be decorated with various stimuli-responsive entities to enable drug targeting and controlled drug release. Self-assembly of amphiphilic cavitands and host–guest complexation represent the two common approaches for preparation of supramolecular nanovesicles with customizable surfaces capable of accommodating different biologically active guest molecules. CBs have been used as smart and multifunctional host macromolecules in cancer therapy. CBs are fabricated via a condensation reaction between formaldehyde and glycoluril units generating barrel-shaped supramolecules with partially enclosed cavities. The unique structure of CBs surrounding an internal hydrophobic cavity allows them to accommodate cationic and neutral guest molecules via ion-dipole and hydrophobic interactions, respectively. Additionally, CBs are stable, safe, and biocompatible, and their surfaces can be decorated with various functional targeting moieties. These advantages have promoted CBs as promising candidates for stimuli-responsive targeted delivery of chemotherapeutics. This review presents the most recent advances in the design of stimuli-responsive nanosystems based on CBs for effective cancer treatment.

Synthesis and characterization of cellulose functionalized zeolitic diatomite as an enhanced carrier of oxaliplatin drug; loading, release, and cytotoxicity

Natural diatomite frustules (D) were incorporated in zeolitization and cellulose functionalization processes to obtain zeolitized diatomite (ZD) and cellulose fibrous/zeolitized diatomite composite (CF/ZD). The modified products were assessed as potential carriers of oxaliplatin drug (OXPL) with enhanced properties. The prepared ZD (112.5 mg/g) and CF/ZD (268.3 mg/g) structures exhibit significantly enhanced encapsulation capacities as compared to raw diatomite (65.9 mg/g). The occurred encapsulation reactions follow the classic Pseudo-first order kinetic (R2 > 0.93) and traditional Langmuir isotherm (R2 = 0.99). The estimated effective encapsulation site density of CF/ZD is 104.8 mg/g which is a notably higher value than ZD (44.6 mg/g) and D (28.4 mg/g). Moreover, each effective site can be occupied with up to 3 molecules of OXPL molecules in vertical forms involving multi-molecular mechanisms. The encapsulation energy (<40 KJ/mol) suggested the predominant effects of the physical mechanisms during the encapsulation reactions. The release profiles of ZD as well as CF/ZD exhibit slow and controlled properties for about 100 h either at pH 5.5 or at pH 7.4. The release kinetic studies involving the obtained diffusion exponent values (>0.45) suggested non-Fickian transport and complex erosion/diffusion release mechanism. These structures exhibit enhanced cytotoxic effects on the HCT-116 cancer cell lines (D (18.78 % cell viability), ZD (9.76 % cell viability), and CF/ZD (3.16 % cell viability).

3D Matrices for Enhanced Encapsulation and Controlled Release of Anti-Inflammatory Bioactive Compounds in Wound Healing

Current trends in the development of wound dressings are oriented towards the use of biopolymer-based materials, due to their unique properties such as non-toxicity, hydrophilicity, biocompatibility and biodegradability, properties that have advantageous therapeutic characteristics. In this regard, the present study aims to develop hydrogels based on cellulose and dextran (CD) and to reveal their anti-inflammatory performance. This purpose is achieved by incorporating plant bioactive polyphenols (PFs) in CD hydrogels. The assessments include establishing the structural characteristics using attenuated total reflection Fourier transformed infrared (ATR-FTIR) spectroscopy, the morphology by scanning electron microscopy (SEM), the swelling degree of hydrogels, the PFs incorporation/release kinetics and the hydrogels' cytotoxicity, together with evaluation of the anti-inflammatory properties of PFs-loaded hydrogels. The results show that the presence of dextran has a positive impact on the hydrogel's structure by decreasing the pore size at the same time as increasing the uniformity and interconnectivity of the pores. In addition, there is an increased degree of swelling and of the encapsulation capacity of PFs, with the increase of the dextran content in hydrogels. The kinetics of PFs released by hydrogels was studied according to the Korsmeyer-Peppas model, and it was observed that the transport mechanisms depend on hydrogels' composition and morphology. Furthermore, CD hydrogels have been shown to promote cell proliferation without cytotoxicity, by successfully culturing fibroblasts and endothelial cells on CD hydrogels (over 80% viability). The anti-inflammatory tests performed in the presence of lipopolysaccharides demonstrate the anti-inflammatory properties of the PFs-loaded hydrogels. All these results provide conclusive evidence on the acceleration of wound healing by inhibiting the inflammation process and support the use of these hydrogels encapsulated with PFs in wound healing applications.

Sustained and Targeted Delivery of Self-Assembled Doxorubicin Nonapeptides Using pH-Responsive Hydrogels for Osteosarcoma Chemotherapy

While chemotherapeutic agents have particularly potent effects in many types of cancer, their clinical applications are still far from satisfactory due to off-target drug exposure, chemotherapy resistance, and adverse effects, especially in osteosarcoma. Therefore, it is clinically promising to construct a novel tumor-targeted drug delivery system to control drug release and alleviate side effects. In this study, a pH-responsive nonapeptide hydrogel was designed and fabricated for the tumor-targeted drug delivery of doxorubicin (DOX). Using a solid-phase synthesis method, a nonapeptide named P1 peptide that is structurally akin to surfactant-like peptides (SLPs) due to its hydrophobic tail and hydrophilic head was synthesized. The physicochemical properties of the P1 hydrogel were characterized via encapsulation capacity, transmission electron microscopy (TEM), circular dichroism (CD), zeta potential, rheological analysis, and drug release studies. We also used in vitro and in vivo experiments to investigate the cytocompatibility and tumor inhibitory efficacy of the drug-loaded peptide hydrogel. The P1 peptide could self-assemble into biodegradable hydrogels under neutral conditions, and the prepared drug-loaded hydrogels exhibited good injectability and biocompatibility. The in vitro drug release studies showed that DOX-P1 hydrogels had high sensitivity to acidic conditions (pH 5.8 versus 7.4, up to 3.6-fold). Furthermore, the in vivo experiments demonstrated that the DOX-P1 hydrogel could not only amplify the therapeutic effect but also increase DOX accumulation at the tumor site. Our study proposes a promising approach to designing a pH-responsive hydrogel with controlled doxorubicin-release action based on self-assembled nonapeptides for targeted chemotherapy.

Proteomics and Molecular Docking Analyses Reveal the Bio-Chemical and Molecular Mechanism Underlying the Hypolipidemic Activity of Nano-Liposomal Bioactive Peptides in 3T3-L1 Adipocytes

Obesity is a global health concern. Physical activities and eating nutrient-rich functional foods can prevent obesity. In this study, nano-liposomal encapsulated bioactive peptides (BPs) were developed to reduce cellular lipids. The peptide sequence NH2-PCGVPMLTVAEQAQ-CO2H was chemically synthesized. The limited membrane permeability of the BPs was improved by encapsulating the BPs with a nano-liposomal carrier, which was produced by thin-layer formation. The nano-liposomal BPs had a diameter of ~157 nm and were monodispersed in solution. The encapsulation capacity was 61.2 ± 3.2%. The nano-liposomal BPs had no significant cytotoxicity on the tested cells, keratinocytes, fibroblasts, and adipocytes. The in vitro hypolipidemic activity significantly promoted the breakdown of triglycerides (TGs). Lipid droplet staining was correlated with TG content. Proteomics analysis identified 2418 differentially expressed proteins. The nano-liposomal BPs affected various biochemical pathways beyond lipolysis. The nano-liposomal BP treatment decreased the fatty acid synthase expression by 17.41 ± 1.17%. HDOCK revealed that the BPs inhibited fatty acid synthase (FAS) at the thioesterase domain. The HDOCK score of the BPs was lower than that of orlistat, a known obesity drug, indicating stronger binding. Proteomics and molecular docking analyses confirmed that the nano-liposomal BPs were suitable for use in functional foods to prevent obesity.

Design and Evaluation of Pegylated Large 3D Pore Ferrisilicate as a Potential Insulin Protein Therapy to Treat Diabetic Mellitus.

An iron-based SBA-16 mesoporous silica (ferrisilicate) with a large surface area and three-dimensional (3D) pores is explored as a potential insulin delivery vehicle with improved encapsulation and loading efficiency. Fe was incorporated into a framework of ferrisilicate using the isomorphous substitution technique for direct synthesis. Fe3+ species were identified using diffuse reflectance spectroscopy. The large surface area (804 m2/g), cubic pores (3.2 nm) and insulin loading were characterized using XRD, BET surface area, FTIR and TEM analyses. For pH sensitivity, the ferrisilicate was wrapped with polyethylene glycol (MW = 400 Daltons) (PEG). For comparison, Fe (10 wt%) was impregnated on a Korea Advanced Institute of Science and Technology Number 6 (KIT-6) sieve and Mesocellular Silica Foam (MSU-F). Insulin loading was optimized, and its release mechanism was studied using the dialysis membrane technique (MWCO = 14,000 Da) at physiological pH = 7.4, 6.8 and 1.2. The kinetics of the drug's release was studied using different structured/insulin nanoformulations, including Santa Barbara Amorphous materials (SBA-15, SBA-16), MSU-F, ultra-large-pore FDU-12 (ULPFDU-12) and ferrisilicates. A different insulin adsorption times (0.08-1 h), insulin/ferrisilicate ratios (0.125-1.0) and drug release rates at different pH were examined using the Korsmeyer-Peppas model. The rate of drug release and the diffusion mechanisms were obtained based on the release constant (k) and release exponent (n). The cytotoxicity of the nanoformulation was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay using human foreskin fibroblast (HFF-1) cells. A low cytotoxicity was observed for this nanoformulation starting at the highest concentrations used, namely, 400 and 800 μg. The hypoglycemic activity of insulin/ferrisilicate/PEG on acute administration in Wistar rats was studied using doses of 2, 5 and 10 mg/kg body weight. The developed facile ferrisilicate/PEG nanoformulation showed a high insulin encapsulation and loading capacity with pH-sensitive insulin release for potential delivery through the oral route.

Novel poly(ester amide) derived from tyrosine amino acid for targeted pulmonary drug delivery of fluticasone propionate

AbstractNanoaggregates made from amino acid‐based polymers have been an important platform for targeted drug delivery systems such as the lungs. Therefore, the aim of the present study is to develop tyrosine‐based poly(ester amide)s (Tyr‐PEA) for dry powder inhaler (DPI) of a potent drug (fluticasone propionate [FP]) using interfacial polymerization. The molecular and surface profiling characteristics were evaluated using Fourier‐transformed infrared spectroscopy, X‐ray diffraction, transmission electron microscopy, particle size analysis, nuclear magnetic resonance, differential scanning calorimetry, and scanning electron micrographs. The aerodynamic performance was evaluated using the NGI. The results confirmed the formation of the PEA and FP‐loaded Tyr‐PEA with an average particle size of, 45.39 ± 6.32 nm. The produced FP/Tyr‐PEA showed entrapment efficiency and encapsulation capacity of FP of 92.32% and 0.526% respectively, which enabled the delivery of this potent drug in a reasonable dose. The in‐vitro performance of the FP‐loaded PEA was compared to a marketed product and results revealed a significant enhancement of the emitted dose (87.29% vs. 59% respectively [t‐test, p &lt; 0.05]). FP‐loaded Tyr‐PEA produced a higher respirable dose when compared to the marketed FP DPI (48.63 μg vs. 34.15 μg). Overall, FP‐loaded Tyr‐PEA was successfully prepared with optimal performance. Tyr‐PEA‐based nanoparticles provide a potential platform for targeted drug delivery, particularly potent actives.

Fabrication of glycated yeast cell protein via Maillard reaction for delivery of curcumin: improved environmental stability, antioxidant activity, and bioaccessibility.

The application of curcumin (CUR) in the food industry is limited by its instability, hydrophobicity and low bioavailability. Yeast cell protein (YCP) is a by-product of spent brewer's yeast, which has the potential to deliver bioactive substances. However, the environmental stresses such as pH, salt and heat treatment has restricted its application in the food industry. Maillard reaction as a non-enzymatic browning reaction can improve protein stability under environmental stress. The CUR was successfully encapsulated into the hydrophobic core of YCP/glycated YCP (GYCP) and enhanced by hydrogen bonding, resulting in static fluorescence quenching of YCP/GYCP. The average diameter and dispersibility of GYPC-CUR nanocomplex were significantly improved after glucose glycation (121.40 nm versus 139.70 nm). Moreover, the encapsulation capacity of CUR was not influenced by glucose glycation. The oxidative stability and bioaccessibility of CUR in nanocomplexes were increased compared with free CUR, especially complexed with GYCP conjugates. Steric hindrance provided by glucose conjugation improved the enviriomental stability, oxidative activity and bioaccessibility of CUR in nanocomplexes. Thus, glucose-glycated YCP has potential application as a delivery carrier for hydrophobic compounds in functional foods. © 2022 Society of Chemical Industry.

Grafted chitosan nanogel with 3,4-methylenedioxycinnamic acid: synthesis, characterization and application in the encapsulation of monoterpenes with antifungal properties

Herein, a novel grafted chitosan nanogel with 3,4-methylenedioxycinnamic acid was carried out aiming at the encapsulation of the monoterpenes carvacrol and thymol, with the purpose of developing a material that can be used in the control of the fungus Microsporum canis. The nanogel encapsulation efficiency showed an encapsulation capacity of 12.9% carvacrol and 13.3% thymol. When in an aqueous medium the nanogel with the respective encapsulated monoterpene oils was able to form stable nanoparticles. The nanogels chitosan-g-3,4-methylenedioxycinnamic acid-carvacrol and chitosan-g-3,4-methylenedioxycinnamic acid-thymol showed antifungal potential against the fungus Microsporum canis, being able to inhibit mycelial growth by 100.00 and 93.13%, respectively.

Nanoparticles Methods for Hydrophobic Drugs — A Novel Approach: Graphical Abstract

The current scenario shifts the advancement of technology toward nanotechnology as well as nanoparticles (NPs). Both are extensively used in pharmaceutical drug delivery also. NPs play a key role in the encapsulation of hydrophobic as well as hydrophilic drugs into the polymeric shells which leads to an increase in the solubility, absorption, encapsulation, and drug loading capacity of the drugs. The major limitations of hydrophobic drugs are solubility issues which hindered the drug’s bioavailability. These limitations can be overcome by polymeric NPs. Both subtypes of polymeric NPs, i.e., nanosphere and nanocapsules are also for the encapsulation of hydrophobic drugs. Our graphical review focused on hydrophobic drug encapsulation through polymeric NP formulation only via two methods, i.e., nanoprecipitation as well as solvent evaporation methods. Both methods are extensively used for hydrophobic drugs and also hold unique properties. The nanoprecipitation method is a single-step method based upon the nucleation process, whereas the solvent evaporation method is a two-step emulsification method. The present graphical review summarized the available remedies through NPs to increase the solubility of hydrophobic drugs.