Fabrication and characterization of dihydromyricetin encapsulated zein-caseinate nanoparticles and its bioavailability in rat

Insights into the preparation of zein nanoparticles by continuous membrane nanoprecipitation

Nanoparticles (NPs) preparation is limited to an exclusive use in batch processes and small-scale formulations. The use of membranes as high-performance micromixers is expected to open new scenarios to overcome limitations of conventional nanoprecipitation system such as stirred tank (ST) nanoprecipitation. The ability of the porous membrane to add uniformly one phase to another and govern their mixing at the membrane interface seems to be an important parameter for obtaining uniform NPs. Inorganic membranes (pore size of 1 μm) were used to carry out membrane nanoprecipitation (MN) to form Zein nanoparticles (ZNPs) at pores level by non-solvent induced phase separation. A systematic study of the preparation of ZNPs in the ST and MN systems was carried out to establish the Ouzo diagram. The influence of zein concentration and solvent to non-solvent ratio on the size and size distribution of ZNPs was also investigated. A wider stable Ouzo zone was obtained with MN than with the ST process. ZNPs size increased from 100 nm up to 700 nm, while maintaining low polydispersity index (PDI < 0.2). The results demonstrate the suitability of MN for the continuous production of ZNPs and open the possibility of scaling up the nanoprecipitation process.

Multi-spectroscopies and molecular docking insights into the interaction mechanism and antioxidant activity of isoquercetin and zein nanoparticles

The purpose of this study was to compare and characterize the theoretical properties and interaction mechanisms of zein and isoquercetin (ISO) from experimental and theoretical perspectives. Zein nanoparticles with different ISO concentrations (ZINPs) were prepared by the antisolvent precipitation method. The experimental results indicated all particles appeared spherical. When the mass ratio of zein to ISO was 10:1, the encapsulation efficiency of ZINPs reached 88.19 % with an average diameter of 126.67 nm. The multispectral method and molecular docking results confirmed that hydrogen bonding and van der Waals force played a dominant role for the binding of ISO to zein, and the primary fluorescence quenching mechanism for zein by ISO was static quenching. Furthermore, ZINPs had greater solubility and antioxidant activity, as well as inhibited the release of ISO during simulated gastrointestinal digestion processes. This research contributes to the understanding of the non-covalent binding mechanism between zein and ISO, providing a theoretical basis for the construction of ISO active carriers.

Enrichment of the flavonoid fraction from Eucommia ulmoides leaves by a liquid antisolvent precipitation method and evaluation of antioxidant activities in vitro and in vivo

Eucommia ulmoides leaves originate from the dry leaves of the Eucommia ulmoides plant. Flavonoids are the main functional components of Eucommia ulmoides leaves. Some flavonoids such as rutin, kaempferol and quercetin are rich in Eucommia ulmoides, and they have outstanding antioxidant efficacy. However, the poor water solubility significantly affects the bioavailability of flavonoids. In this study, we used a liquid antisolvent precipitation (LAP) method to enrich the main flavonoid fractions in Eucommia ulmoides leaves, and prepared nanoparticles by the LAP method to increase flavonoids' solubility and antioxidant properties. The technological parameters were optimized by Box-Behnken Design (BBD) software and were displayed as follows: (1) total flavonoids (TFs) concentration: 83 mg mL^-1; (2) antisolvent-solvent ratio: 11; (3) deposition temperature: 27 °C. Under optimal processing conditions, the purity and recovery rate of TFs were 88.32% ± 2.54% and 88.08% ± 2.13%, respectively. In vitro experiments showed that the radical scavenging IC₅₀ values for DPPH, ABTS, hydroxyl radicals and superoxide anions were 16.72 ± 1.07, 10.76 ± 0.13, 227.68 ± 18.23 and 335.86 ± 15.98 μg mL^-1, respectively. In vivo studies showed that the obtained purified flavonoid (PF) (100, 200, 400 mg kg^-1) treatment is able to improve CCl₄-induced liver and kidney damage through adjusting, superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) levels. These results demonstrated that the LAP method is capable of extracting TFs from Eucommia ulmoides leaves with high bioaccessibility.

Flavonoids as a therapeutical option for the treatment of thrombotic complications associated with COVID-19

The SARS-CoV-2 outbreak has been one of the largest public health crises globally, while thrombotic complications have emerged as an important factor contributing to mortality. Therefore, compounds that regulate the processes involved in thrombosis could represent a dietary strategy to prevent thrombotic complications involved in COVID-19. In August 2022, various databases were consulted using the keywords "flavonoids", "antiplatelet", "anticoagulant", "fibrinolytic", and "nitric oxide". Studies conducted between 2019 and 2022 were chosen. Flavonoids, at concentrations mainly between 2 and 300 μM, are capable of regulating platelet aggregation, blood coagulation, fibrinolysis, and nitric oxide production due to their action on multiple receptors and enzymes. Most of the studies have been carried out through in vitro and in silico models, and limited studies have reported the in vivo and clinical effect of flavonoids. Currently, quercetin has been the only flavonoid evaluated clinically in patients with COVID-19 for its effect on D-dimer levels. Therefore, clinical studies in COVID-19 patients analyzing the effect on platelet, coagulant, fibrinolytic, and nitric oxide parameters are required. In addition, further high-quality studies that consider cytotoxic safety and bioavailability are required to firmly propose flavonoids as a treatment for the thrombotic complications implicated in COVID-19.

Liquid antisolvent crystallization of pharmaceutical compounds: current status and future perspectives

The present work reviews the liquid antisolvent crystallization (LASC) to prepare the nanoparticle of pharmaceutical compounds to enhance their solubility, dissolution rate, and bioavailability. The application of ultrasound and additives is discussed to prepare the particles with narrow size distribution. The use of ionic liquid as an alternative to conventional organic solvent is presented. Herbal compounds, also known for low aqueous solubility and limited clinical application, have been crystalized by LASC and discussed here. The particle characteristics such as particle size and particle size distribution are interpreted in terms of supersaturation, nucleation, and growth phenomena. To overcome the disadvantage of batch crystallization, the scientific literature on continuous flow reactors is also reviewed. LASC in a microfluidic device is emerging as a promising technique. The different design of the microfluidic device and their application in LASC are discussed. The combination of the LASC technique with traditional techniques such as high-pressure homogenization and spray drying is presented. A comparison of product characteristics prepared by LASC and the supercritical CO₂ antisolvent method is discussed to show that LASC is an attractive and inexpensive alternative for nanoparticle preparation. One of the major strengths of this paper is a discussion on less-explored applications of LASC in pharmaceutical research to attract the attention of future researchers.

Enhanced oral bioavailability from food protein nanoparticles: A mini review

The oral route is the most desirable drug administration path. The oral bioavailability is always compromised from the poor physicochemical and/or biopharmaceutical properties of the active pharmaceutical ingredients. Food protein nanoparticles show promise for oral drug delivery, with improved biosafety and cost-effectiveness compared to polymeric nanoparticles. More importantly, diverse food proteins provide "choice and variety" to meet the challenges faced by different drugs in oral delivery resulting from low solubility, poor permeability, and gastrointestinal stability. The abundance of hydroxyl, amino, and carboxyl groups in food proteins allows easy surface modification of the nanoparticles to impart unique functions. Albeit being in its infancy, food protein nanoparticles exhibit high capability to enhance oral bioavailability of a wide range of drugs from small molecules to biomacromolecules. Considering the rapid growth of the field, the achievements and mechanisms of food protein nanoparticles in enhancing oral bioavailability are reviewed. Factors affecting the performance of food protein nanoparticles are discussed with the purpose to inspire the development of food protein nanoparticle-based oral drug delivery systems.

Enhanced Bioavailability and Pharmacokinetics of a Natural Self-Emulsifying Reversible Hybrid-Hydrogel System of Quercetin: A Randomized Double-Blinded Comparative Crossover Study

Despite the vast array of health beneficial pharmacological effects, the bioavailability of the dietary flavonoid quercetin was found to be poor due to insolubility, incompatibility, and rapid biotransformation. Herein, we investigated the solubility, morphology, particle size, stability, in vitro release, and human pharmacokinetics of a hybrid-hydrogel formulation of quercetin (FQ-35) using fenugreek galactomannans as the hydrogel scaffold. Physicochemical characterization revealed that the crystalline quercetin was well encapsulated in the hydrogel matrix to form translucent microgel particles of FQ-35 with enhanced solubility (96-fold). The mean particle size was found to be 183.6 ± 42.7 nm with a zeta potential of 35.1 ± 3.8 mV. Pharmacokinetic investigation on healthy volunteers (N = 16) employing tandem mass spectrometric (ultra-performance liquid chromatography-electrospray tandem mass spectrometry) measurements of the concentration of free (unconjugated) and conjugated quercetin metabolites revealed an 18.6-fold improvement in free (unconjugated) quercetin bioavailability and 62-fold improvement in total quercetin (sum of free and conjugated) bioavailability, compared to the unformulated quercetin extracted from Sophora japonica. In summary, the natural self-emulsifying reversible hybrid-hydrogel delivery system was found to offer significant solubility, stability, and bioavailability of quercetin upon single-dose oral administration.

Strategic developments in the drug delivery of natural product dihydromyricetin: applications, prospects, and challenges

Dihydromyricetin (DHM) is an important natural flavonoid that has attracted much attention because of its various functions such as protecting the cardiovascular system and liver, treating cancer and neurodegenerative diseases, and anti-inflammation effect, etc. Despite its great development potential in pharmacy, DHM has some problems in pharmaceutical applications such as low solubility, permeability, and stability. To settle these issues, extensive research has been carried out on its physicochemical properties and dosage forms to produce all kinds of DHM preparations in the past ten years. In addition, the combined use of DHM with other drugs is a promising strategy to expand the application of DHM. However, although invention patents for DHM preparations have been issued in several countries, the current transformation of DHM research results into market products is insufficient. To date, there is still a lack of deep research into the pharmacokinetics, pharmacodynamics, toxicology, and action mechanism of DHM preparations. Besides, preparations for combined therapy of DHM with other drugs are scarcely reported, which necessitates the development of dosage forms for this application. Apart from medicine, the development of DHM in the food industry is also of great potential. Due to its multiple effects and excellent safety, DHM preparations can be developed for functional drinks and foods. Through this review, we hope to draw more attention to the development potential of DHM and the above challenges and provide valuable references for the research and development of other natural products with a similar structure-activity relationship to this drug.

Chalcone-1-Deoxynojirimycin Heterozygote Reduced the Blood Glucose Concentration and Alleviated the Adverse Symptoms and Intestinal Flora Disorder of Diabetes Mellitus Rats

Chalcone-1-deoxynojirimycin heterozygote (DC-5), a novel compound which was designed and synthesized in our laboratory for diabetes treatment, showed an extremely strong in vitro inhibitory activity on α-glucosidase in our previous studies. In the current research, its potential in vivo anti-diabetic effects were further investigated by integration detection and the analysis of blood glucose concentration, blood biochemical parameters, tissue section and gut microbiota of the diabetic rats. The results indicated that oral administration of DC-5 significantly reduced the fasting blood glucose and postprandial blood glucose, both in diabetic and normal rats; meanwhile, it alleviated the adverse symptoms of elevated blood lipid level and lipid metabolism disorder in diabetic rats. Furthermore, DC-5 effectively decreased the organ coefficient and alleviated the pathological changes of the liver, kidney and small intestine of the diabetic rats at the same time. Moreover, the results of 16S rDNA gene sequencing analysis suggested that DC-5 significantly increased the ratio of Firmicutes to Bacteroidetes and improved the disorder of gut microbiota in diabetic rats. In conclusion, DC-5 displayed a good therapeutic effect on the diabetic rats, and therefore had a good application prospect in hypoglycemic drugs and foods.

Potential uses of milk proteins as encapsulation walls for bioactive compounds: A review

Milk proteins have received much awareness due to their bioactivity. However, their encapsulation functions have not attracted enough attention. Milk proteins as encapsulation walls can increase the bioavailability of bioactive compounds. As the benefits of bioactive compounds are critically determined by bioavailability, the effect of interactions between milk proteins and active substances is a critical topic. In the present review, we summarize the effects of milk proteins as encapsulation walls on the bioavailability of active substances with a special focus. The methods and mechanisms of interactions between milk proteins and active substances are also discussed. The evidence collected in the present review suggests that when active substances are encapsulated by milk proteins, the bioavailability of active substances can be significantly affected. This review also provides valuable guidelines for the use of milk protein-based microcarriers.

Present Status, Challenges, and Prospects of Dihydromyricetin in the Battle against Cancer

Dihydromyricetin (DHM) is a natural flavonoid compound extracted from Ampelopsis grossedentata that has been used for centuries in traditional Chinese medicine. DHM has attracted intensive attention due to its numerous beneficial activities, such as hepatoprotection, cardioprotection, antioxidant, and anti-inflammation. In addition, DHM inhibits the progression of cancers such as lung cancer, hepatocellular cancer, breast cancer, melanoma, and malignant reproductive systems through multiple mechanisms, including antiangiogenesis, antiproliferation, apoptosis, and inhibition of invasion and migration. Notably, DHM also activates autophagy at different levels, exerting a dual-regulatory effect on cancers. Mechanistically, DHM can effectively regulate mammalian target of rapamycin (mTOR), noncoding RNA-mediated signaling, phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway, nuclear factor-κB (NF-κB), p53, and endoplasmic reticulum stress (ER stress)-driven signaling in different types of cancers. DHM has also been shown to have inhibitory effects on various regulators that trigger epithelial–mesenchymal transition (EMT). Furthermore, DHM exhibits a remarkable anticancer reversal ability when used in combination with drugs such as adriamycin, nedaplatin, and other drugs. However, the low bioavailability of DHM limits its potential applications, which are improved through structural modification and the exploration of novel dosage forms. Therefore, DHM may become a promising candidate for treating malignancies alone or combined with conventional anticancer strategies used in clinical practice.

Multifunctional Selenium Nanoparticles with Different Surface Modifications Ameliorate Neuroinflammation through the Gut Microbiota-NLRP3 Inflammasome-Brain Axis in APP/PS1 Mice

Neuroinflammation plays a critical role in Alzheimer's disease (AD). However, it is still unknown if neuroinflammation can be effectively treated using selenium nanoparticles (SeNPs) with different surface modifications. In this study, SeNPs were coated with dihydromyricetin (DMY), a natural polyphenol, to obtain DMY@SeNPs. Given that DMY@SeNPs are unstable under physiological conditions, they were decorated step-by-step with chitosan (CS/DMY@SeNPs) and with the blood brain barrier (BBB) targeting peptide Tg (TGNYKALHPHNG) to yield Tg-CS/DMY@SeNPs, which significantly reduced the aggregation of Aβ and improved the anti-inflammatory effects of SeNPs in vitro. The mechanisms of CS/DMY@SeNPs and Tg-CS/DMY@SeNPs on regulating neuroinflammation are different. Only Tg-CS/DMY@SeNPs can cross the BBB; therefore, Tg-CS/DMY@SeNPs more successfully inhibited Aβ aggregation and reduced inflammatory cytokine secretion via the NF-κB pathway in the brain of APP/PS1 mice compared to CS/DMY@SeNPs. Furthermore, both types of nanoparticles, however, were able to repair the gut barrier and regulate the population of inflammatory-related gut microbiota such as Bifidobacterium, Dubosiella, and Desulfovibrio. Of note, the relative abundance of Gordonibacter was only enhanced by Tg-CS/DMY@SeNPs, thereby downregulating the protein expression of the NLRP3 inflammasome and the concentrations of serum inflammatory factors. This demonstrates that Tg-CS/DMY@SeNPs ameliorate neuroinflammation through the gut microbiota-NLRP3 inflammasome-brain axis. Overall, our data suggest that Tg-CS/DMY@SeNPs are an ideal drug candidate for AD treatment.

The anti-obesity and gut microbiota modulating effects of taxifolin in C57BL/6J mice fed with a high-fat diet

BACKGROUND

Taxifolin is a natural dihydroflavonol found in many plants and health products. In the present study, its anti-obesity and gut microbiota modulating effects were studied. C57BL/6J mice were fed with a high-fat diet (HFD) supplemented with taxifolin (0, 0.5 and 1 mg mL^-1 , respectively) in drinking water for 15 weeks.

RESULTS

Taxifolin supplementation showed no influence on food and water intake. However, it decreased body weight gain, inhibited fat accumulation, and decreased total cholesterol and triacylglycerol level in mice liver. Taxifolin enhanced superoxide dismutase (SOD) activity in mice liver, which in turn protected the liver from lipid peroxidation damage. It also improved insulin resistance in obese mice. Metagenomic analysis of bacterial 16S rRNA demonstrated that HFD decreased gut microbiota diversity and caused dysbiosis. However, taxifolin improved the gut microbiota diversity and decreased the Firmicutes/Bacteroidetes ratio. In particular, it inhibited Proteobacteria from blooming, this being a signature of dysbiosis in gut microbiota.

CONCLUSION

Taxifolin ameliorated the symptoms of obesity, hepatic steatosis, lipid peroxidation, insulin resistance, and gut microbiota dysbiosis in HFD fed C57BL/6J mice. © 2021 Society of Chemical Industry.

A review of factors affecting the stability of zein-based nanoparticles loaded with bioactive compounds: from construction to application

Zein-based nanoparticles loaded with bioactive compounds have positive prospects in the food industry, but an important limiting factor for development is colloidal instability. Currently, extensive researches are focused on solving the instability of zein nanoparticles, but since the beginning of the studies, there has not been a summary of the factors affecting the stability of zein-based nanoparticles. In the present work, the factors were reviewed comprehensively from the perspective of carrier construction and application evaluation. The former mainly includes type, quantity, and characteristics of biopolymer, the mass ratio of biopolymer/bioactive compound to zein, blending sequence of biopolymer, and location of encapsulated bioactive compounds. The latter mainly includes pH, heating, ionic strength, storage, freeze-drying, and gastrointestinal digestion. The former is the prerequisite for the success of the latter. The challenge is that stability research is limited to the laboratory level, and it is difficult to ensure that the stability results are suitable for commercial food matrices due to their complexity. At the laboratory level, the future trends are the influence of external energy and the cross-complexity and uniformity of stability research. The review is expected to provide systematic understanding and guidance for the development of zein-based nanoparticles stability.

Dihydromyricetin Improves Cognitive Impairments in d-Galactose-Induced Aging Mice through Regulating Oxidative Stress and Inhibition of Acetylcholinesterase

SCOPE

Alzheimer's disease (AD) is a neurodegenerative disease with phenomena of cognitive impairments. Oxidative stress and cholinergic system dysfunction are two widely studied pathogenesis of AD. Dihydromyricetin (DMY) is a natural dihydroflavonol with many bioactivities. In this study, it is aimed to investigate the effects of DMY on cognitive impairment in d-galactose (d-gal) induced aging mice.

METHODS AND RESULTS

Mice are intraperitoneally injected with d-gal for 16 weeks, and DMY is supplemented in drinking water. The results show that DMY significantly improves d-gal-induced cognitive impairments in novel object recognition and Y-maze studies. H&E and TUNEL staining show that DMY could improve histopathological changes and cell apoptosis in mice brain. DMY effectively induces the activities of catalase, superoxide dismutase and glutathione peroxidase, and reduces malondialdehyde level in mice brain and liver. Furthermore, DMY reduces cholinergic injury by inhibiting the activity of Acetylcholinesterase (AChE) in mice brain. In vitro studies show that DMY is a non-competitive inhibitor of AChE with IC50 value of 161.2 µg mL^-1 .

CONCLUSION

DMY alleviates the cognitive impairments in d-gal-induced aging mice partly through regulating oxidative stress and inhibition of acetylcholinesterase.

A comparative study of optimized naringenin nanoformulations using nano-carriers (PLA/PVA and zein/pectin) for improvement of bioavailability

Naringenin, a lipophilic flavanone of citrus fruits, was encapsulated for enhanced bioavailability using biodegradable polymers of polylactic acid/polyvinyl alcohol (PLA/PVA) as well as zein/pectin as P/P-Nar-NPs and Z/P-Nar-NPs, respectively. The formulation variables were optimized using response surface methodology to achieve smaller particle size with higher surface charge and encapsulation efficiencies. The optimized formulations were physically characterized by SEM, FTIR, TGA and XRD techniques. Compared to Z/P-Nar-NPs, the P/P-Nar-NPs had better encapsulation efficiency and sustained release of naringenin under simulated gastrointestinal conditions. Furthermore, the oral administration of single dose of free and nanoforms of naringenin in rats (90 mg/kg b.wt) showed higher efficacy of PLA/PVA in improving the relative bioavailability of naringenin (4.7-fold) as compared to the zein/pectin polymer (1.9-fold). Overall, the present study provides insights into the formulation performance of the encapsulated bioactive compound under different polymeric matrices.

A multifaceted review on dihydromyricetin resources, extraction, bioavailability, biotransformation, bioactivities, and food applications with future perspectives to maximize its value

Natural bioactive compounds present a better alternative to prevent and treat chronic diseases owing to their lower toxicity and abundant resources. (+)-Dihydromyricetin (DMY) is a flavanonol, possessing numerous interesting bioactivities with abundant resources. This review provides a comprehensive overview of the recent advances in DMY natural resources, stereoisomerism, physicochemical properties, extraction, biosynthesis, pharmacokinetics, and biotransformation. Stereoisomerism of DMY should be considered for better indication of its efficacy. Biotechnological approach presents a potential tool for the production of DMY using microbial cell factories. DMY high instability is related to its powerful antioxidant capacity due to pyrogallol moiety in ring B, and whether preparation of other analogues could demonstrate improved properties. DMY demonstrates poor bioavailability based on its low solubility and permeability with several attempts to improve its pharmacokinetics and efficacy. DMY possesses various pharmacological effects, which have been proven by many in vitro and in vivo experiments, while clinical trials are rather scarce, with underlying action mechanisms remaining unclear. Consequently, to maximize the usefulness of DMY in nutraceuticals, improvement in bioavailability, and better understanding of its actions mechanisms and drug interactions ought to be examined in the future along with more clinical evidence.

In vivo and in vitro comparison of three astilbin encapsulated zein nanoparticles with different outer shells

Three shell materials, lecithin (ZNP-L), chitosan (ZNP-CH) and sodium caseinate (ZNP-SC), were used to prepare core-shell zein nanoparticles. Astilbin was encapsulated as a model flavonoid to compare the influence of the shell materials on zein nanoparticles both in vitro and in vivo. The particle size was moderately increased by lecithin and sodium caseinate, but notably increased by chitosan. All the shell materials provided good redispersibility for the nanoparticles and significantly improved the colloidal stability. Chitosan and sodium caseinate significantly delayed and decreased the feces excretion of astilbin in rats, while lecithin exhibited a very weak effect. The results may be attributed to the difference in mucoadhesive properties between the shell materials. As a consequence, the bioavailability values of astilbin in rats were 18.2, 9.3 and 1.89 times increased through ZNP-CH, ZNP-SC and ZNP-L compared with that of free astilbin, respectively.

Assembling cyanidin-3-O-glucoside by using low-viscosity alginate to improve its in vitro bioaccessibility and in vivo bioavailability

In this work, an enteric soluble alginate was proposed to improve the absorption efficiency of cyanidin-3-O-glucoside (C3G) through molecular self-assembly. Under the optimized conditions, the obtained low-viscosity alginate (LVA) was released completely during the simulated gastrointestinal digestion and an LVA-C3G complex with 84.2% binding efficiency was acquired. Fourier transform infrared spectroscopy displayed that the characteristic spectrum of C3G had disappeared after the LVA conjugation. Furthermore, based on the analysis of scanning electron microscopy and differential scanning calorimetry, a porous network structure and the shifted endothermic peak in the thermograms were observed, further confirming the formation of a complex between LVA and C3G. The results of simulated gastrointestinal digestion reveal that the LVA assembly significantly (p < 0.05) improved the bioaccessibility of C3G. Correspondingly, the C3G level in mouse plasma was increased by 27.4% in the C3G-LVA group. This suggests the suitability of LVA as an oral delivery vehicle for dietary anthocyanins.

Fabrication of nanostructured multi-unit vehicle for intestinal-specific delivery and controlled release of peptide

An oral multi-unit delivery system was developed by incorporating the nanoparticle (NP) into the nanofiber mat and its efficiency for intestinal-specific delivery and controlled release of a peptide (insulin) was investigated. Initially, the influence of deacetylation degree (DD) of chitosan and ionic gelation methods on the properties of NPs was studied. High DD (95%) chitosan was attributed to higher encapsulation efficiency and stability when crosslinked with polyanion tripolyphosphate. Subsequently, the multi-unit system was fabricated using a pH-sensitive polymer (sodium alginate) as the coating layer to further encapsulate the NP. Fiber mat with an average diameter of 481 ± 47 nm could significantly decrease the burst release of insulin in acidic condition and release most amount of insulin (>60%) in the simulated intestinal medium. Furthermore, the encapsulated peptide remained in good integrity. This multi-unit carrier provides the better-designed vehicle for intestinal-specific delivery and controlled release of the peptide.

Self-Assembled Micelles Improve the Oral Bioavailability of Dihydromyricetin and Anti-Acute Alcoholism Activity

Dihydromyricetin (DMY) is highly effective in counteracting acute alcohol intoxication. However, its poor aqueous solubility and permeability lead to the low oral bioavailability and limit its clinic application. The aim of this work is to use Solutol®HS15 (HS 15) as surfactant to develop novel micelle to enhance the oral bioavailability of DMY by improving its solubility and permeability. The DMY-loaded Solutol®HS15 micelles (DMY-Ms) were prepared by the thin-film hydration method. The particle size of DMY-Ms was 13.97 ± 0.82 nm with an acceptable polydispersity index of 0.197 ± 0.015. Upon entrapped in micelles, the solubility of DMY in water was increased more than 25-fold. The DMY-Ms had better sustained release property than that of pure DMY. In single-pass intestinal perfusion models, the absorption rate constant (Ka) and permeability coefficient (Papp) of DMY-Ms were 5.5-fold and 3.0-fold than that of pure DMY, respectively. The relative bioavailability of the DMY-Ms (AUC_0-∞) was 205% compared with that of pure DMY (AUC_0-∞), indicating potential for clinical application. After administering DMY-Ms, there was much lower blood alcohol level and shorter duration of the loss of righting relax (LORR) in drunk animals compared with that treated by pure DMY. In addition, the oral administration of DMY-Ms greatly reduced oxidative stress, and significantly defended liver and gastric mucosa from alcoholic damages in mice with alcohol-induced tissue injury. Taken together, HS 15-based micelle system greatly improves the bioavailability of DMY and represents a promising strategy for the management of acute alcoholism. Graphical abstract.

Development of curcumin-loaded zein nanoparticles for transport across the blood-brain barrier and inhibition of glioblastoma cell growth

Glioblastoma (GBM) is a devastating primary brain tumor resistant to conventional therapies. A major obstacle to GBM treatment is the blood-brain barrier (BBB), or blood-glioma barrier, which prevents the transport of systemically administered (chemotherapeutic) drugs into the tumor. This study reports the design of dodecamer peptide (G23)-functionalized polydopamine (pD)-coated curcumin-loaded zein nanoparticles (CUR-ZpD-G23 NPs) that efficiently traversed the BBB, and delivered curcumin to glioblastoma cells. The NPs enhanced the cellular uptake of curcumin by C6 glioma cells compared to free curcumin, and showed high penetration into 3D tumor spheroids. Functionalization of the NPs with G23 stimulated BBB crossing and tumor spheroid penetration. Moreover, the NPs markedly inhibited proliferation and migration and induced cell death in liquid and soft agar models of C6 glioma cell growth. Fluorescence microscopy and flow cytometry studies showed that the CUR-ZpD-G23 NPs increased cellular ROS production and induced apoptosis of C6 glioma cells. Following in vivo intravenous injection in zebrafish, ZpD-G23 NPs demonstrated the ability to circulate, which is a first prerequisite for their use in targeted drug delivery. In conclusion, zein-polydopamine-G23 NPs show potential as a drug delivery platform for therapy of GBM, which requires further validation in in vivo glioblastoma models.