Hydrophobic Bioactive Molecules Research Articles

Fabrication of hydrophobic drug-loaded Zeolitic Imidazolate Framework-8 (ZIF-8) for enhanced anti-bacterial activity

Current study presents a novel approach for constructing small hydrophobic biomolecules embedded within zeolitic imidazolate framework-8 (ZIF-8) with exceptional antibacterial properties. In this method, ZIF-8 is synthesized from zinc acetate and 2-methylimidazole in the presence or absence of small hydrophobic bioactive molecules like rutin, rosmarinic acid, and morin. Scanning electron microscopy (SEM) analysis reveals that the synthesized ZIF-8 nanoparticles exhibit mostly hexagonal shape with size 200 nm which is further increased upon drug encapsulation. The synthesis of ZIF-8 and drug-loaded ZIF-8 is confirmed through FTIR, UV–vis spectroscopy, XRD, TGA, and EDX analyses. Zeta potential measurements show values ranging from -14.5 to -23.97 mV for both ZIF-8 and drug-loaded ZIF-8 nanoparticles. The drug loading content is determined to be 5 %, 9 %, and 16 % for morin, rutin, and rosmarinic acid, respectively. All the drug-loaded ZIF-8 formulations exhibit a pH-dependent drug release pattern, with maximal drug release observed at lower pH levels. Most importantly, these formulations demonstrate potent antibacterial activity against both Gram-positive (Enterococcus faecalis and Bacillus subtilis) and Gram-negative (Escherichia coli) bacterial strains. Specifically, ZIF-8/RUT exhibit maximum zone of inhibition (ZOI ∼ 51 mm) against all tested bacterial strains. ZIF-8/MOR and ZIF-8/RUT exhibit MIC values ranging from 2.0 to 3.0 mg/mL and MBC values from 6 to 9 mg/mL against all the tested bacteria. Among the formulations, ZIF-8/MOR and ZIF-8/RUT exhibit synergistic antibacterial effect, whereas ZIF-8/RMA possess less antibacterial potency against all the tested bacteria and mostly exhibit additive effect. Our findings suggest that these newly developed nano-formulations hold potential for the creation of highly effective antibacterial agents.

Preparation and application of curcumin loaded with citric acid crosslinked chitosan-gelatin hydrogels

While oral administration offers safety benefits, its therapeutic efficacy is hindered by various physiological factors within the body. In this study, a novel approach was explored using a matrix consisting of 2 % chitosan and 2 % gelatin, with citric acid (CA) serving as a green cross-linking agent (ranging from 0.4 % to 1.0 %), and curcumin (Cur) as the model drug to formulate hydrogel carriers. The results showed that a 0.4 % CA concentration, the hydrogel (CGA0.4) reached swelling equilibrium in deionized water within 40 min, exhibiting a maximum swelling index was 539 g/g. The addition of Cur to the CGA hydrogel (CGACur) notably enhanced release efficiency, particularly in simulated intestinal fluid, where Cur release rates exceeded 40 % within 100 min compared to below 8 % in other solutions. Among these hydrogels, CGA0.4Cur exhibited the fastest degradation rate in the combined solution, reaching >90 % degradation after 7 days. Additionally, Cur and CA demonstrated positive effects on the tensile strength, antioxidant activity and antibacterial activity of hydrogels. Compare to the bioaccessibility of CGC (27 %), those of CGACur had increased to over 34 %. These findings offer provide theoretical support for CA-crosslinked chitosan/gelatin gels in delivering hydrophobic bioactive molecules and their application in intestinal drug delivery system.

Fabrication of caffeoylquinic acid-loaded burdock polysaccharide nanoparticles and their antioxidant activity in hydrogen peroxide-damaged HepaRG cells

Herein, burdock polysaccharide (BP) and modified burdock polysaccharide (MBP) were prepared, followed by the fabrication of chlorogenic acid (CA)-BP, CA-MBP, isochlorogenic acid A (ICA)-BP, and ICA-MBP nanoparticles. Afterward, the structural characteristics, physical stability, digestive characteristics, and antioxidant activity of hydrogen peroxide (H2O2)-damaged HepaRG cells were evaluated. The result indicated that the loading capacities of CA in BP-CA and MBP-CA were 0.14 and 0.53 μg/mg, respectively. Conversely, the loading capacities of ICA in BP-ICA and MBP-ICA were 0.36 and 0.60 μg/mg, respectively. Four complex nanoparticles exhibited excellent physical stability under different pH values, temperatures, and ionic concentrations, especially MBP-CA and MBP-ICA. Moreover, four complex nanoparticles could protect caffeoylquinic acid from being released in gastric fluid. All six samples exhibited high antioxidant activity in H2O2-induced HepaRG cells, especially BP and MBP-CA. These findings indicated that caffeoylquinic acid–polysaccharide complexes were successfully prepared and highlighted the potential of polysaccharides as natural carriers for hydrophobic bioactive molecules.

Preparation, stability and controlled release properties of starch-based micelles for oral delivery of hydrophobic bioactive molecules

Amphiphilic starches incorporating fatty acid ester chains of varying lengths and degrees of substitution (DS) were synthesized to fabricate starch-based micelles for oral delivery of hydrophobic bioactive molecules. The assembly of the amphiphilic starches is influenced by the concentration, temperature, and the chain length and DS of their fatty acid ester chain. Highly acidic environment can hydrolyze the amphiphilic starches, resulting in the formation of small-sized micelles. Conversely, high ionic concentration hinders the self-assembly of amphiphilic starches and the digestive fluids can dilute the amphiphilic starches concentration, leading to the micelle dissociation. However, amphiphilic starches with longer chain length and/or higher DS of the fatty acid ester chain possess greater hydrophobicity, enhancing the stability of starch-based micelles under varying conditions and favouring the protection of Trp-2 peptides during storage. The micelles demonstrate high cell bioaccessibility for Trp-2 peptides, with 59.25 % of Trp-2 peptides being transferred by the intestinal epithelium. These findings suggest a potential starch-based micelle system can be adjusted for the oral delivery of hydrophobic bioactive molecules.

Novel microemulsions formulated from sodium N-Lauroyl sarcosinate as nanocarrier for encapsulation of α-Tocopherol

Oil-in-water (o/w) microemulsions (MEs) are gaining increasing attention as nanocarriers for the encapsulation and delivery of hydrophobic bioactive molecules which has huge applications in cosmetic, pharmacological, food and beverage industries. However, the major challenge is to formulate these MEs from biodegradable and biocompatible components in low concentration to form stable formulations. In the current work, physiochemical characterization of blank and α-tocopherol loaded o/w MEs formulated using the biodegradable amino-acid based sodium N-lauroyl sarcosinate (SNLS) as surfactant was performed. These MEs were utilized as potential nanocarriers to solubilize and encapsulate an antioxidant α-tocopherol. The utilization of o/w MEs increased the solubility of α-tocopherol from 0.1% in 10% SNLS solution to 0.2% and 0.8% in MEs without and with cosurfactant respectively. The effect of cosurfactant, concentration of Smix (SNLS:butanol = 1:1) and oil was evaluated using conductivity, viscosity studies and encapsulation efficiency to select the optimum composition for encapsulation. The Z-average size of blank MEs without and with cosurfactant was 304 nm and 199 nm respectively with low PDI and negative zeta potential values determine the enhanced stability of these MEs. The HRTEM images revealed the spherical shape of o/w MEs with darker oily core and were utilized to study the effect of cosurfactant and encapsulation of α-tocopherol on the size and morphology of o/w ME droplets. Further, FTIR studies showed the molecular interactions in α-tocopherol and in the optimized ME. In addition to this, the in-vitro antioxidant study of α-tocopherol loaded MEs was determined by the DPPH free radical scavenging activity and the IC50 value was 9 mg/mL for the optimized ME containing 0.5% α-tocopherol. The contact angle studies revealed excellent wetting and spreading ability of MEs on the hydrophobic surface. Thus, SNLS based o/w MEs could be utilized as potential nanocarriers for the encapsulation and delivery of α-tocopherol.

Effect of interfacially-engineered nanoemulsions of linoleic acid stabilized by mixed surfactant systems and curcumin on their physicochemical properties, induction times, and peroxidation stability

Nanoemulsions have become the best candidates for loading hydrophobic bioactive molecules and enhancing their shelf-life and bioavailability in the food, pharmaceutical and cosmetic industries. Mixture of different surfactants modulates their interfacial characteristics, thereby imposing a direct effect in improving their physicochemical and nutritional characteristics. Herein, we report the formulation of oil-in-water nanoemulsions stabilized with either single or mixture of surfactants having different electric charges like Tween 20 (T20, nonionic), sodium salt of Lauroyl Sarcosine (LS, anionic) and 3-(N,N-dimethylmyristylammonio)propanesulfonate (DPS, zwitterionic) to control the peroxidation of linoleic acid by using curcumin as the potential antioxidant. The distribution of H+ ions at the interface and the variation in the values of observed rate constant (kobs) is assessed by employing the novel Chemical Kinetic method based on the reaction between arenediazonium ions and the antioxidant. For single-surfactant systems, nanoemulsions containing pure T20 or LS showed good oxidative stability whereas for mixed-surfactant systems, the oxidative stability increases with increasing concentration of LS and decreasing concentration of DPS. This could be explained on the basis of physicochemical characterization of nanoemulsions, interfacial H+ ion concentration, and solubility characteristics of curcumin. The study shows great promise of such mixed surfactant systems, ignored so far, for providing a novel and tailored formulation of nanoemulsions for improving the oxidative stability of linoleic acid.

Preparation of high internal phase Pickering emulsion by centrifugation for 3D printing and astaxanthin delivery

Oil in water high internal phase Pickering emulsion (HIPEs) stabilized by edible colloid particles have attracted considerable attention for three-dimensional (3D) printing and delivery of a hydrophobic bioactive. In this paper, a facile route for preparing oil in water HIPEs was demonstrated, only requiring centrifuging gliadin/gelatinized starch nanocomposites (G/SNPs) stabilized pre-emulsions. The surface properties of G/SNPs were engineered which helped prevent oil coalescence during centrifugation, while obtaining HIPEs with oil phase fractions up to 77.3%, simultaneously. The resultant HIPEs exhibited shear-thinning behavior with high solid viscoelasticity. Furthermore, HIPEs with internal phase fraction above 80% were successfully prepared simply by adjusting the ionic strength. The HIPEs with suitable rheology properties for 3D printing were obtained, and the enhanced viscoelasticity and thixotropic recovery could be attributed to the electrostatic shielding under higher ionic strength. In addition, the light stability and bioaccessibility of astaxanthin were significantly improved by HIPEs, and more than 90% astaxanthin was retained after heating at 95 °C for 30 min. These results proved a new route for producing HIPEs with improved performance, opening new possibilities for manufacturing future food and delivery of hydrophobic bioactive molecules.

The interaction mechanism and the functionality of yeast protein with hydrophilic and hydrophobic bioactive molecules

Yeast protein is a kind of yeast-source high-quality complete protein. The coexistence of bioactive molecules with yeast protein may influence its physicochemical property. This study discussed the interaction mechanism of yeast protein with two bioactive molecules, the hydrophobic curcumin and the hydrophilic epigallocatechin gallate (EGCG). Results indicated that curcumin and EGCG could interact with yeast protein with different binding stoichiometric numbers (0.8109 ± 0.0695 and 2.7248 ± 0.2422) and binding constants ((3.8152 ± 0.0078) × 104 and (1.1875 ± 0.0440) × 105), respectively. Both EGCG and curcumin decreased the α-helix content while increased the β-sheet proportion, and co-binding remarkably reduced the α-helix proportion relative to the single ligand binding. The co-binding of these two compounds decreased the association extent of the yeast protein, which in turn reduced the diameter of yeast protein-EGCG-curcumin complex. The binding of EGCG with yeast protein improved the thermal stability of curcumin. Moreover, the co-binding improved the emulsification stability of yeast protein, and curcumin exhibited a more remarkable effect in improving the foamability. This work provides a theoretical basis for clarifying the interaction mechanisms of hydrophobic/hydrophilic molecules with yeast protein, and extends the potential applications of the novel fungus protein sources for food function enhancement and bioactive molecule stabilization.

Neuroprotective Properties of Cardoon Leaves Extracts against Neurodevelopmental Deficits in an In Vitro Model of Rett Syndrome Depend on the Extraction Method and Harvest Time.

This study investigates the bioactive properties of different extracts of cardoon leaves in rescuing neuronal development arrest in an in vitro model of Rett syndrome (RTT). Samples were obtained from plants harvested at different maturity stages and extracted with two different methodologies, namely Naviglio® and supercritical carbon dioxide (scCO2). While scCO2 extracts more hydrophobic fractions, the Naviglio® method extracts phenolic compounds and less hydrophobic components. Only the scCO2 cardoon leaves extract obtained from plants harvested in spring induced a significant rescue of neuronal atrophy in RTT neurons, while the scCO2 extract from the autumn harvest stimulated dendrite outgrowth in Wild-Type (WT) neurons. The scCO2 extracts were the richest in squalene, 3ß-taraxerol and lupeol, with concentrations in autumn harvest doubling those in spring harvest. The Naviglio® extract was rich in cynaropicrin and exerted a toxic effect at 20 µM on both WT and RTT neurons. When cynaropicrin, squalene, lupeol and 3ß-taraxerol were tested individually, no positive effect was observed, whereas a significant neurotoxicity of cynaropicrin and lupeol was evident. In conclusion, cardoon leaves extracts with high content of hydrophobic bioactive molecules and low cynaropicrin and lupeol concentrations have pharmacological potential to stimulate neuronal development in RTT and WT neurons in vitro.

Protein Z-based promising carriers for enhancing solubility and bioaccessibility of Xanthohumol

Xanthohumol (XN), as an abundant chalcone in hops, has received increasing attention due to its pharmacologic effects. However, poor solubility and bioaccessibility in aqueous solutions have limited its application. This work reported a novel carrier to improve the solubility and bioaccessibility of XN by using heat-stable, serpin-like protein Z (PZ) derived from barley malt. In this study, the solubility of XN was increased by 145-fold (vs. free XN in water) using 200 μM PZ as the carrier. Fluorescence results demonstrated that XN interacted with PZ via static quenching process, with binding constant (K a ) of 5.70 × 10 4 L/mol at 298 K. PZ as a serine protease inhibitor exhibited excellent in vitro digestive stability that could inhibit trypsin with a low half inhibitory concentration (IC 50 ) of 3.90 ± 0.03 mg/L and showed only 26.54 ± 0.70% degree of hydrolysis after gastrointestinal digestion. Furthermore, the retention ratio of XN was 50.28 ± 1.80% after gastrointestinal digestion, which is 8-fold higher than XN alone, suggesting that PZ remarkably enhanced the bioaccessibility of XN. Molecular dynamics simulation analysis revealed that XN was bound within the hydrophobic pocket of PZ, near the Glu338 residue of PZ, whereas the external active loop of PZ was involved in binding with trypsin. This helped to elucidate the roles of PZ in improving the bioaccessibility of XN that PZ encapsulated XN in its hydrophobic cavity, without influencing its inhibition on trypsin. These findings suggest that PZ may be developed as carriers that protect XN or other hydrophobic bioactive molecules in the gastrointestinal tract. • The solubility of xanthohumol (XN) bound with protein Z increased about 145-fold. • Protein Z can form stable complexes with XN mainly via hydrophobic interactions. • Encapsulation of XN in the binding pocket of protein Z improved its bioaccessibility. • Exterior ring of protein Z interacted with trypsin to inhibit protein Z degradation.

Creating burdock polysaccharide-oleanolic acid-ursolic acid nanoparticles to deliver enhanced anti-inflammatory effects: fabrication, structural characterization and property evaluation

This study explored the potential of polysaccharides from Actium lappa (ALPs) as natural wall materials for producing ALP-based nanoparticles to deliver poorly water-soluble oleanolic acid (OA) and ursolic acid (UA). Encapsulating OA+UA with ALPs (ALP:OA+UA, 50:1; OA:UA, 1:1) changed the crystalline nature to a more amorphous state through hydrogen bonding and involving O–H/C–O/O–C–O groups. ALP-OA/UA nanoparticles had a particle size and zeta potential (in water) of 199.1 nm/–7.15 mV, with a narrow unimodal size distribution, and excellent pH, salt solution, temperature and storage stability. Compared with ALPs, ALP-OA/UA nanoparticles showed enhanced anti-inflammatory activity (especially at a dose of 100 μg/mL) in a CuSO4-induced zebrafish inflammation model via down-regulating the NF-κB signalling pathway and gene expression of associated transcription factors and cytokines (TNF-α, IL-1β and IL-8). Therefore, ALP-based nanoparticles are natural and anti-inflammatory carriers for hydrophobic bioactive molecules.

Trans-Cinnamaldehyde Eluting Porous Silicon Microparticles Mitigate Cariogenic Biofilms

Dental caries, a preventable disease, is caused by highly-adherent, acid-producing biofilms composed of bacteria and yeasts. Current caries-preventive approaches are ineffective in controlling biofilm development. Recent studies demonstrate definite advantages in using natural compounds such as trans-cinnamaldehyde in thwarting biofilm assembly, and yet, the remarkable difficulty in delivering such hydrophobic bioactive molecules prevents further development. To address this critical challenge, we have developed an innovative platform composed of components with a proven track record of safety. We fabricated and thoroughly characterised porous silicon (pSi) microparticles to carry and deliver the natural phenyl propanoid trans-cinnamaldehyde (TC). We investigated its effects on preventing the development of cross-kingdom biofilms (Streptococcus mutans and Candida albicans), typical of dental caries found in children. The prepared pSi microparticles were roughly cubic in structure with 70–75% porosity, to which the TC (pSi-TC) was loaded with about 45% efficiency. The pSi-TC particles exhibited a controlled release of the cargo over a 14-day period. Notably, pSi-TC significantly inhibited biofilms, specifically downregulating the glucan synthesis pathways, leading to reduced adhesion to the substrate. Acid production, a vital virulent trait for caries development, was also hindered by pSi-TC. This pioneering study highlights the potential to develop the novel pSi-TC as a dental caries-preventive material.

The Interaction of Yeast Protein with Hydrophilic and Hydrophobic Bioactive Molecules, the Binding, Structure, and Function Evaluation

The Interaction of Yeast Protein with Hydrophilic and Hydrophobic Bioactive Molecules, the Binding, Structure, and Function Evaluation

Enzyme-instructed self-assembly (EISA) assists the self-assembly and hydrogelation of hydrophobic peptides.

Enzyme-instructed self-assembly (EISA) has several advantages in the preparation of supramolecular self-assembly materials for biomedical applications. In this study, we demonstrated that the enzyme-instructed self-assembly (EISA) strategy could assist the self-assembly and hydrogelation of two hydrophobic and bioactive peptides, tyroservatide (YSV) and laminin pentapeptide (YIGSR). We first synthesized the peptide derivatives of Nap-GFFYSV (peptide 1) and Nap-GFFYIGSR (peptide 2) and found that both peptides could not self-assemble into hydrogels due to their poor solubility. We therefore designed the phosphorylated precursors of the two hydrophobic peptides, Nap-GFFpYSV (precursor 1) and Nap-GFFpYIGSR (precursor 2), respectively, which had good solubility and can be dephosphorylated by alkaline phosphatase (ALP) to form supramolecular hydrogels. In addition, we found that the EISA could also occur on the surface of cells that overexpress ALP. The EISA strategy was a powerful method to generate hydrogels of hydrophobic compounds. We envision the big promise of the strategy in the preparation of biomaterials and nanomaterials of hydrophobic bioactive molecules.

Bovine serum albumin cold-set emulsion gel mediated by transglutaminase / glucono-δ-lactone coupling precursors: Fabrication, characteristics and embedding efficiency of hydrophobic bioactive components

Encapsulation and protection of hydrophobic bioactive compounds using food-based sustainable materials are challenging issues in recent decade. Herein, we provided a feasible strategy to fabricate bovine serum albumin (BSA) cold-set emulsion gel by using microbial transglutaminase (MTGase) and glucono-δ-lactone (GDL) as substrate precursors. Its embedding potential towards quercetin and vitamin E (VE) were thereby evaluated. The results showed that hardness and springiness of the gels decreased along with increasing of GDL (≥0.3%, w/v) in the presence of 0.1% (w/v) MTGase. Storage modulus (G′) and loss modulus (G'') reached the maximum at 0.3% (w/v) GDL, while the water-holding capacity (WHC) of gels (≥85% (w/v)) was positively correlated to GDL addition. The pattern of confocal laser scanning microscope (CLSM) further confirmed the occurrence of smaller oil droplets in fabricated gels with relatively high abundance of GDL. Consequently, the embedding efficiencies for quercetin and VE reached up to 94.80% (w/v) and 97.94% (w/v) respectively. The harder gels had much better controlled-release performance than the softer ones. The work shed light on the rational design of food protein gels to protect, stabilize and delivery of small hydrophobic bioactive molecules.

On improving bioaccessibility and targeted release of curcumin-whey protein complex microparticles in food

Curcumin is a bioactive food component, with poor bioaccessibility due to low water solubility and stability. Spray drying retained and in fact enhanced curcumin-whey protein isolate (WPI) complexation via desolvation, lowering the amount of unbound curcumin to <5% wt after drying, forming microparticles with better water solubility, stability, and bioaccessibility than raw curcumin. The desolvated microparticles encapsulated 3.47 ± 0.05 mg/g curcumin, almost one order of magnitude higher than the un-desolvated sample 0.37 ± 0.03 mg/g. After incorporation into yogurt, the rapid-release formula liberated 87% curcumin, whereas the targeted-release one discharged 44% before entering the simulated intestinal condition. Most of the yogurt sensory properties were not adversely affected, except for colour and curcumin flavour. This study proposed a strategy in which food ingredients containing hydrophobic bioactive small molecules can be incorporated into a food matrix to improve bioaccessibility and targeted release, without affecting their sensory properties.

Development of a nanoparticle delivery system based on zein/polysaccharide complexes.

Zein, an alcohol-soluble protein in corn, can self-assemble into spherical nanoparticles, which makes it an ideal carrier material for the encapsulation of hydrophobic bioactive molecules. However, zein nanoparticles easily aggregate in water and are sensitive to enzymatic degradation in the digestive system. A strategy to overcome their limitations is the incorporation of polysaccharides as a second polymer layer that provides stability to zein nanoparticles. This review introduces the characteristics of zein as they relate to understanding the formation of zein/polysaccharide nanoparticles. Particular attention is paid to the preparation methods for the zein/polysaccharide nanoparticles, as well as to the morphological observation methods and detection mechanism. Moreover, the properties and applications of zein/polysaccharide nanoparticles are highlighted.

Preparation, characterization, and antioxidant activity of zein nanoparticles stabilized by whey protein nanofibrils

The application of natural biopolymers to develop colloidal carriers for delivering hydrophobic bioactive molecules has become one of the hottest topics in food science. In this study, a simple pH-driven method to prepare whey protein nanofibrils stabilized zein nanoparticles was developed. The formation, structure, intermolecular interactions, rheological properties, in vitro digestion, and antioxidant activity of the nanoparticles were investigated. When the mass ratio of zein and whey protein nanofibrils was 1:0.8, the hydrodynamic diameter and zeta potential of the nanoparticles were 413 nm and − 25 mV, respectively. Transmission electron microscope photographs showed that the nanoparticles were a spherical core-shell structure. Fourier transform infrared spectroscopy and surface hydrophobicity measurements indicated that whey protein nanofibrils adsorbed to the surface of zein aggregates through hydrogen bonding and hydrophobic interactions. Differential scanning calorimetry tests confirmed the formation of nanoparticles improved the thermal stability of zein and whey protein nanofibrils. The nanoparticles exhibited less shear-thinning behavior with low apparent viscosity, and it can't be degraded in simulated gastric fluid but can be in simulated intestinal fluid. The antioxidant activity of the nanoparticles was increased by in vitro antioxidant assay when compared to whey protein nanofibrils. This new technology to develop zein-whey protein nanoparticles may be used for preparing nanoparticles of other similar hydrophobic food ingredients. And the findings of this study may provide a theoretical basis for preparation of nanoparticles as a nutrient delivery system.

Physicochemical and bio-functional properties of walnut proteins as affected by trypsin-mediated hydrolysis

The walnut proteins were trypsin-hydrolyzed for 0, 15, 30, 60 and 120 min and the effects of hydrolysis on the structural, functional, antioxidant, bioactive-loading, and angiotensin converting enzyme (ACE)-inhibitory properties of walnut protein were studied. The trypsin-mediated hydrolysis of walnut proteins was monitored using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and an O-phthaldialdehyde spectrophotometric assay. The unfolding of walnut protein structure during the hydrolysis process was confirmed using intrinsic fluorescence spectroscopy which increased the surface hydrophobicity of protein. The solubility of walnut protein was increased from 17 to 63% after 2 h of trypsin-mediated hydrolysis. The walnut protein hydrolysates showed higher surface activity compared to the native non-hydrolyzed protein, which significantly improved their foaming and emulsifying properties. The hydrolysates also showed significant enhanced antioxidant activity, namely, ABTS radical quenching activity and reducing power due to the release of active antioxidant sequences during the enzymatic hydrolysis. The ability of walnut proteins to inhibit the activity of ACE and their capacity to load hydrophobic bioactive molecules including curcumin and quercetin were also considerably improved by treating with trypsin. The results of this study suggested that the trypsin-mediated hydrolysis could be used as an efficient technology to produce bioactive multi-functional hydrolysates from walnut proteins.

Fabricating β-cyclodextrin based pH-responsive nanotheranostics as a programmable polymeric nanocapsule for simultaneous diagnosis and therapy.

BackgroundFabrication of a smart drug delivery system that could dramatically increase the efficiency of chemotherapeutic drugs and reduce the side effects is still a challenge for pharmaceutical researchers. By the emergence of nanotechnology, a huge window was opened towards this goal, and a wide type of nanocarriers were introduced for delivering the chemotherapeutic to the cancer cells, among them are cyclodextrins with the ability to host different types of hydrophobic bioactive molecules through inclusion complexation process.AimThe aim of this study is to design and fabricate a pH-responsive theranostic nanocapsule based on cyclodextrin supramolecular nano-structure.Materials and methodsThis nanostructure contains iron oxide nanoparticles in the core surrounded with three polymeric layers including polymeric β-cyclodextrin, polyacrylic acid conjugated to sulfadiazine, and polyethylenimine functionalized with β-cyclodextrin. Sulfadiazine is a pH-responsive hydrophobic component capable of making inclusion complex with β-cyclodextrin available in the first and third layers. Doxorubicin, as an anti-cancer drug model, was chosen and the drug loading and release pattern were determined at normal and acidic pH. Moreover, the biocompatibility of the nanocapsule (with/without drug component) was examined using different techniques such as MTT assay, complement activation, coagulation assay, and hemolysis.ResultsThe results revealed the successful preparation of a spherical nanocapsule with mean size 43±1.5 nm and negatively charge of −43 mV that show 160% loading efficacy. Moreover, the nanocapsule has an on/off switching release pattern in response to pH that leads to drug released in low acidic pH. The results of the biocompatibility tests indicated that this nano drug delivery system had no effect on blood and immune components while it could affect cancer cells even at very low concentrations (0.3 μg mL−1).ConclusionThe obtained results suggest that this is a “switchable” theranostic nanocapsule with potential application as an ideal delivery system for simultaneous cancer diagnosis and therapy.