Simulated Gastrointestinal Fluids Research Articles

Tailored design of pH-responsive microbeads for oral delivery of lactoferrin nanotherapeutics of colon cancer

Colorectal cancer, one of the most fatal cancer types, has an unmet need for the development of targeted oral therapeutics. To address this, we propose to engineer a multiparticulate system to enhance the efficacy of anticancer drugs for treatment of colon cancer. We have developed a dual ligand- and pH-responsive multiparticulate system for oral drug delivery to the colon. Indomethacin (IND) and quercetin (QCT) preformulated as nanosuspensions (NSps) or liquid crystalline nanoparticles (LCNPs), respectively, were co-encapsulated into pH-responsive CA/HEC-MBs microbeads via ionoptropic gelation. To enhance tumor targeting, both nanoparticles were further coated with lactoferrin (Lf), which allows binding with Lf receptors on cancerous HCT-116 cells, resulting in higher internalization and superior cytotoxicity. Among various simulated gastrointestinal fluids, the engineered CA/HEC-MBs incorporating nanoparticles successfully released the drugs only in the colon (pH 6.8). Oral administration of both LF-targeted nanostructured microbeads into DMH-induced colorectal cancer bearing mice revealed superior in vivo anti-tumor efficacy. The microbeads efficiently reduced CEA and PCNA protein levels as well as the serum levels of IL-6, IL-1, and TNF-α. Apoptosis was also upregulated, as evidenced by increased Bax/Bcl2 ratio and increased expression levels of activated caspase-3 and caspase-9. Overall, these findings suggest that orally administered LF-targeted nanoparticle-based MBs for co-delivery of QCT and IND represent a promising alternative to conventional colon cancer therapy.

Effects of different solid particle sizes on oat protein isolate and pectin particle-stabilized Pickering emulsions and their use as delivery systems

Oat protein isolate (OPI)/high methoxyl pectin (HMP) complexes (OPP) were prepared to stabilized Pickering emulsions and applied as nutraceutical delivery systems. The different mass ratios and pH changed the interactions between OPI and HMP that caused the different size of OPP. Specifically, smaller particle size of OPP (125.7–297.6 nm) were formed when hydrophobic interactions along with electrostatic forces predominant in OPP (OPI:HMP = 3:1, pH 4, 5). Among these particles, OPP-2 could stabilize Pickering emulsion efficiently through formation of dense interfacial film, which exhibited the highest apparent viscosity and the smallest average droplet size (23.39 μm). Moreover, OPP-2 stabilized Pickering emulsions with superior stability not only exhibited higher encapsulation efficiency of 85.63%, but also could control curcumin release in simulated gastrointestinal fluids to improve curcumin's bioaccessibility. These results verified the possibility of OPP to be a Pickering emulsions stabilizer, and also identified its potential to be a stable delivery system for bioactive compounds.

Oral sericin ameliorates type 2 diabetes through passive intestinal and bypass transport into the systemic circulation

Ethnopharmacological relevanceBoiled silkworm cocoons have been used to treat 'Xiaoke disease' (diabetes mellitus) recorded in Chinese medicine for over 800 years. In recent years, it has been found that the active substance silk sericin (SS) has therapeutic benefits in treating type 2 diabetes mellitus (T2DM). SS promotes pancreatic islet signalling, the proliferation of pancreatic islet cells, and insulin secretion. It is inferred that SS enters the bloodstream after oral administration and plays a role in the body's circulation. As a natural protein, SS needs to resist digestion by proteases in the gastrointestinal tract and cross the gastrointestinal barrier after oral administration. It is currently unclear how SS crosses the gastrointestinal barrier and whether it exerts therapeutic effects on T2DM by entering the circulation. Aim of the studyTo study how SS crosses the gastrointestinal barrier and whether it enters the body circulation to exert a therapeutic effect on T2DM. Materials and methodsSS was extracted from silkworm cocoons using an alkaline method with sodium carbonate. The antidigestive capacity of SS was detected using SDS-PAGE gel electrophoresis experiments. The mode of uptake and translocation of orally consumed SS in vivo was analysed using the AP-side to BL-side and BL-side-AP-side translocations, apparent Permeability coefficient(Papp), and Exocytosis rates(ER). The study compared the differences between the adSS group and the adSS+EDTA group by using Ethylenediaminetetraacetic acid(EDTA) to separate the tight junctions between Caco-2 cells. The aim was to analyse whether the transport mode of oral filaggrin proteins in vivo could be absorbed by bypass transport. By administering SS through oral and intraperitoneal injection to type 2 diabetic mice, we measured its concentration in the blood, as well as blood glucose and insulin levels, to determine its effectiveness in treating diabetes and its ability to enter the body's circulation for treatment. ResultsThe molecular weight of SS decreased from 10k∼25kDa to 10k∼15kDa after in vitro simulated gastrointestinal fluid digestion, indicating its good antidigestive properties. The apparent Papp was greater than 1×10-6 cm·s-1 , and the ER was between 0.5 and 1.5, indicating that adSS was well-absorbed and mainly passively transported. The Caco-2 cell model showed that the addition of EDTA promoted the transport of adSS, resulting in significantly larger Papp and ER values, indicating that adSS was absorbed by bypass transport. After oral administration of SS, the concentration of SS in the blood was lower than after intraperitoneal injection, which is 60% of intraperitoneal administration. Mice with a T2DM model who were administered SS for 5 weeks showed significant improvement in insulin resistance and glucose tolerance. Additionally, the pancreatic tissue appeared more regular. In the treatment of T2DM, injections of SS have been shown to be more effective than oral administration. Both oral and intraperitoneal injections have been partially involved in the circulation. ConclusionsSS is enzymatically cleaved by proteolytic enzymes in the gastrointestinal tract. The smaller molecules are partially absorbed into the body's circulation through passive and paracrine transport, exerting a therapeutic effect on T2DM.

Evaluation of Probiotic Properties and Safety of Lactobacillus helveticus LH10 Derived from Vinegar through Comprehensive Analysis of Genotype and Phenotype.

The probiotic potential of Lactobacillus helveticus LH10, derived from vinegar Pei, a brewing mixture, was assessed through genotype and phenotype analyses. The assembled genome was comprised of 1,810,276 bp and predicted a total of 2044 coding sequences (CDSs). Based on the whole genome sequence analysis, two bacteriocin gene clusters were identified, while no pathogenic genes were detected. In in vitro experiments, L. helveticus LH10 exhibited excellent tolerance to simulated gastrointestinal fluid, a positive hydrophobic interaction with xylene, and good auto-aggregation properties. Additionally, this strain demonstrated varying degrees of resistance to five antibiotics, strong antagonistic activity against four tested pathogens, and no hemolytic activity. Therefore, L. helveticus LH10 holds great promise as a potential probiotic candidate deserving further investigation for its beneficial effects on human health.

In vitro and in vivo digestibility of prebiotic galactooligosacharides synthesized by β-galactosidase from Lactobacillus delbruecki subsp. bulgaricus CRL450.

The general assumption that prebiotics reach the colon without any alterations has been challenged. Some in vitro and in vivo studies have demonstrated that 'non-digestible' oligosaccharides are digested to different degrees depending on their structural composition. In the present study, we compared different methods aiming to assess the digestibility of oligosaccharides synthesized by β-galactosidase (β-gal) of Lactobacillus delbruecki subsp. bulgaricus CRL450 (CRL450-β-gal) from lactose, lactulose and lactitol. In the simulated gastrointestinal fluid method, no changes were observed. However, the oligosaccharides synthesized by CRL450-β-gal were partially hydrolyzed in vitro, depending on their structure and composition, with rat small intestinal extract (RSIE) and small intestinal brush-border membrane vesicles (BBMV) from pig. Digestion of some oligosaccharides increased when mixtures were fed to C57BL/6 mice used as in vivo model; however, lactulose-oligosaccharides were the most resistant to the physiological conditions of mice. In general β (1→6) linked products showed higher resistance compared to β (1→3) oligosaccharides. In vitro digestion methods, without disaccharidases, may underestimate the importance of carbohydrates hydrolysis in the small intestine. Although BVMM and RSIE digestion assays are appropriate in vitro methods for these studies, in vivo studies remain the most reliable for understanding what actually happens in the digestion of oligosaccharides. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

The Probiotic Properties and Safety of Limosilactobacillus mucosae NK41 and Bifidobacterium longum NK46.

Probiotics should possess specific properties to exert beneficial effects, and their safety must be ensured for human consumption. The purpose of this study was to evaluate the probiotic properties and safety of Limosilactobacillus mucosae NK41 and Bifidobacterium longum NK46 isolated from human feces in vitro. Both strains exhibited high resistance to simulated gastrointestinal fluid. Furthermore, probiotic-related cell surface characteristics including auto-aggregation and cell surface hydrophobicity were assessed by measuring the absorbance at a wavelength of 600 nm, which demonstrated good auto-aggregation ability and affinity for xylene, indicating their effective adhesion to Caco-2 cells. In addition, hemolytic, gelatinase, and β-glucuronidase activities were found to be negative in both strains. The susceptibility to nine commonly used antibiotics was assessed using the broth macrodilution method, which demonstrated that both strains were susceptible to all tested antibiotics. Furthermore, L. mucosae NK41 and B. longum NK46 produced significantly higher levels of L-lactate (71.8 ± 0.7% and 97.8 ± 0.4%) than D-lactate (28.2 ± 0.7% and 2.2 ± 0.4%, respectively). Using PCR amplification to investigate genes associated with virulence factors, we found that neither strain harbored any virulence genes. These findings suggest that L. mucosae NK41 and B. longum NK46 have the potential to be used as probiotics and are considered safe for human consumption.

Optimization of Preparation Conditions for Quercetin Nanoliposomes Using Response Surface Methodology and Evaluation of Their Stability.

Quercetin is a flavonol compound with excellent biological activities. However, quercetin exhibits poor stability and solubility in water, which limits its application. In this study, quercetin nanoliposomes (QUE-NL-1) were prepared using an ultrasonic thin-film dispersion method, and the preparation conditions were optimized using response surface methodology. The optimal conditions for preparing QUE-NL-1 were as follows: an evaporation temperature of 35 °C, a drug concentration of 0.20 mg/mL, and a lipid bile ratio of 4:1. The encapsulation rate of QUE-NL-1 is (63.73 ± 2.09)%, the average particle size is 134.11 nm, and the average absolute value of the zeta potential is 37.50 and PDI = 0.24. By analyzing the storage temperature, storage time, and leakage rate of QUE-NL-1 in simulated gastrointestinal fluid, it was found that quercetin exhibits good stability after embedding and can achieve sustained release in intestinal juice. In addition, the cytotoxicity of QUE-NL-1 was not significant, and the survival rate of Caco-2 cells was >90% when the concentration range of QUE-NL-1 was 0.1-0.4 mg/mL. This study provides an efficient method for preparing QUE-NL-1 with small particle sizes, good stability, and high safety, which is of great significance for expanding the application range of quercetin.

Ultrasound-enhanced covalent reaction of gliadin: the inhibition of antigenicity and its potential mechanisms.

Wheat proteins can be divided into water/salt-soluble protein (albumin/globulin) and water/salt-insoluble protein (gliadins and glutenins (Glu)) according to solubility. Gliadins (Glia) are one of the major allergens in wheat. The inhibition of Glia antigenicity by conventional processing techniques was not satisfactory. In this study, free radical oxidation was used to induce covalent reactions. The effects of covalent reactions by high-intensity ultrasound (HIU) of different powers was compared. The enhancement of covalent grafting effectiveness between gliadin and (-)-epigallo-catechin 3-gallate (EGCG) was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, matrix-assisted laser desorption/ionization-time-of-flight-mass spectrometry and Folin-Ciocalteu tests. HIU caused protein deconvolution and disrupted the intrastrand disulfide bonds that maintain the tertiary structure, causing a shift in the side chain structure, as proved by Fourier, fluorescence and Raman spectroscopic analysis. Comparatively, the antigenic response of the conjugates formed in the sonication environment was significantly weaker, while these conjugates were more readily hydrolyzed and less antigenic during simulated gastrointestinal fluid digestion. HIU-enhanced free radical oxidation caused further transformation of the spatial structure of Glia, which hid or destroyed the antigenic epitope, effectively inhibiting protein antigenicity. This study widened the application of polyphenol modification in the inhibition of wheat allergens. © 2024 Society of Chemical Industry.

Evaluation of probiotic properties of a Brevibacillus laterosporus strain.

Brevibacillus laterosporus is a strain of probiotic bacteria that has been widely used in pest control, cash crop, and other production areas. However, few studies have been conducted on its use as a feed additive in animals. Therefore, the probiotic potential of B. laterosporus PBC01 was evaluated by characterizing hydrophobicity, auto-aggregation activity, bile salt and simulated gastrointestinal fluid tolerance, bienzymatic, and antibacterial activity. Antibiotic susceptibility, hemolysis assays, and supplemental feeding of mice were also performed to evaluate safety features. Our results showed that B. laterosporus PBC01 had moderate hydrophobicity, high auto-agglutination ability. Meanwhile, B. laterosporus PBC01 had good tolerance to bile salt and simulated gastrointestinal fluid. It had the ability to secrete protease, cellulase, and to inhibit various pathogens. In addition, B. laterosporus PBC01 was sensitive to many antibiotics, and did not produce hemolysin. In the safety assessment of mice, it did not cause any deaths, nor did it affect the cell components of blood, antioxidant capacity, and reproductive health. The study indicated the great probiotic characteristics and safety of B. laterosporus PBC01. This may provide a theoretical basis for the clinical application and development of probiotic-based feed additives.

Stabilization by Chaperone GroEL in Biogenic Selenium Nanoparticles Produced from Bifidobacterium animalis H15 for the Treatment of DSS-Induced Colitis.

Inflammatory bowel diseases have a high rate of mortality and pose a serious threat to global public health. Selenium is an essential trace element, which has been shown to play important roles in redox control and antioxidant defense. Microorganisms play important roles in the reduction of toxic inorganic selenium (selenite and selenate) to less-toxic biogenic selenium nanoparticles (Bio-SeNPs), which have higher biocompatibility. In the present study, novel Bio-SeNPs with high stability were synthesized using probiotic Bifidobacterium animalis subsp. lactis H15, which was isolated from breastfed infant feces. The Bio-SeNPs with a size of 122 nm showed stability at various ionic strengths, temperatures, and in simulated gastrointestinal fluid, while chemosynthetic SeNPs underwent aggregation. The main surface protein in the Bio-SeNPs was identified as chaperone GroEL by liquid chromatography-tandem mass spectrometry. The overexpression and purification of GroEL demonstrated that GroEL controlled the assembly of Bio-SeNPs both in vitro and in vivo. In vivo, oral administration of Bio-SeNPs could alleviate dextran sulfate sodium-induced colitis by decreasing cell apoptosis, increasing antioxidant capacity and the number of proliferating cells, and improving the function of the intestinal mucosal barrier. In vitro experiments verified that Bio-SeNPs inhibited lipopolysaccharide-induced toll-like receptor 4/NF-κB signaling pathway activation. These results suggest that the Bio-SeNPs with high stability could have potential as a nutritional supplement for the treatment of colitis in nanomedicine applications.

STUDY ON FORMULATION OF BACTERIAL CELLULOSE NANOFIBERS-COATED NANOLIPOSOMES CONTAINING PACLITAXEL FOR ORAL ADMINISTRATION

Objective: The low oral bioavailability of paclitaxel (PAC) because of its limited aqueous solubility and poor intestinal permeability after being administered orally suggests the need for a sustained release system. The aim of this study is to produce and evaluate in vitro a nanoliposome system that carries paclitaxel (BCN-LIP-PAC) for oral administration. Methods: Thin-film evaporation and electrostatic deposition methods were used to obtain LIP-PAC and BCN-LIP-PAC. Particle size, polydispersity index (PDI), zeta potential, morphological analysis, entrapment efficiency percentage (EE%), and in vitro dissolution studies were used to characterize the developed systems. Results: The nano-range sizes of LIP-PAC and BCN-LIP-PAC (0.1 % BCN) were 112±4.2 nm and 154±6.4 nm, respectively, where EE % were 80.6±2.3 % and 84.6±1.7 %, respectively. BCN-LIP-PAC exhibited good stability in simulated gastrointestinal fluids. The drug release experiments conducted in vitro showed that BCN-LIP-PAC had obvious sustained release behaviors when compared to LIP-PAC. Furthermore, the release rate of PAC from all LIP-PAC and BCN-LIP-PAC was higher in SIF than in SGF. Conclusion: The preparation, characterization, and evaluation of BCN-LIP-PAC (0.1 % BCN) for oral PAC delivery were all successful. In conclusion, the approach presented herein is a promising option for delivering oral sustained-release PAC.

Stabilization of Black Locust Flower Extract via Encapsulation Using Alginate and Alginate-Chitosan Microparticles.

Black locust flower extract contains various polyphenols and their glucosides contribute to the potential health benefits. After intake of these bioactive compounds and passage through the gastrointestinal tract, their degradation can occur and lead to a loss of biological activity. To overcome this problem, the bioactive compounds should be protected from environmental conditions. This study aimed to encapsulate the black flower extract in the microparticles based on biodegradable polysaccharides, alginate, and chitosan. In the extract, the total antioxidant content was found to be 3.18 ± 0.01 g gallic acid equivalent per 100 g of dry weight. Also, the presence of lipids (16), phenolics (27), organic acids (4), L-aspartic acid derivative, questinol, gibberellic acid, sterol, and saponins (2) was confirmed using the UHPLC-ESI-MS analysis. In vitro assays showed that the extract has weak anti-α-glucosidase activity and moderate antioxidant and cytotoxic activity against the HeLa cell line. The extrusion method with secondary air flow enabled the preparation of microparticles (about 270 μm) encapsulated with extract. An encapsulation efficiency of over 92% was achieved in the alginate and alginate-chitosan microparticles. The swelling study confirmed a lower permeability of alginate-chitosan microparticles compared with alginate microparticles. For both types of microparticles, the release profile of antioxidants in the simulated gastrointestinal fluids at 37 °C followed the Korsmeyer-Peppas model. A lower diffusion coefficient than 0.5 indicated the simple Fick diffusion of antioxidants. The alginate-chitosan microparticles enabled a more sustained release of antioxidants from extract compared to the alginate microparticles. The obtained results indicated an improvement in the antioxidant activity of bioactive compounds from the extract and their protection from degradation in the simulated gastric conditions via encapsulation in the polymer matrixes. Alginate-chitosan showed slightly slower cumulative antioxidant release from microparticles and better antioxidant activity of the extract compared to the alginate system. According to these results, alginate-chitosan microparticles are more suitable for further application in the encapsulation of black locust flower extract. Also, the proposed polymer matrix as a drug delivery system is safe for human use due to its biodegradability and non-toxicity.

Riboflavin-loaded soy protein isolate cold gel treated with combination of high intensity ultrasound and high hydrostatic pressure: Gel structure, physicochemical properties and gastrointestinal digestion fate

Transglutaminase (TGase) was added to soy protein isolate (SPI) dispersion after the combination treatment of high intensity ultrasound (HIU) and high hydrostatic pressure (HHP) to catalyze the formation of cold gel, which was used to encapsulate riboflavin. The structure, physicochemical properties and in vitro digestion characteristics of riboflavin-loaded SPI cold gel were investigated. HIU-HHP combined treatment enhanced the strength, water retention, elastic property, thermal stability and protein denaturation degree of riboflavin-loaded SPI cold gels, and improved the gel network structure, resulting in a higher encapsulation efficiency of riboflavin and its chemical stability under heat and light treatment. HIU-HHP combined treatment reduced the erosion and swelling of SPI cold gel in simulated gastrointestinal fluid, and improved the sustained release effect of SPI gel on riboflavin by changing the digestion mode and rate of gel. In addition, HIU-HHP combined treated gels promoted the directional release of riboflavin in the simulated intestinal fluid, thereby improving its bioaccessibility, which was related to the secondary structure orderliness, tertiary conformation tightness and aggregation degree of protein during the gastrointestinal digestion. Therefore, HIU-HHP combined treatment technology had potential application value in improving the protection, sustained/controlled release and delivery of SPI cold gels for sensitive bioactive compounds.

Development of porous materials via protein/polysaccharides/polyphenols nanoparticles stabilized Pickering high internal phase emulsions for adsorption of Pb2+ and Cu2+ ions

The porous materials (PM) were prepared by the Pickering high internal phase emulsion (PHIPE) template. Firstly, the nanoparticles named as ZHMNPs or MZHMNPs were fabricated based on zein, Hohenbuehelia serotina polysaccharides and Malus baccata (Linn.) Borkh polyphenols without or with Maillard reaction, the average particle sizes and zeta potentials of which were distributed in a range of 718.1–979.4 nm and −21.6–25.2 mV. ZHMNPs possessed the relatively uniform spherical morphology, while MZHMNPs were irregular in shape. With ZHMNPs or MZHMNPs serving as the stabilizers, the PHIPEs were prepared, and exhibited the good viscoelasticity and excellent storage and freeze–thaw stabilities. Based on above PHIPEs template, the constructed PM possessed the large specific surface area and uniform pore structure. Through the investigations of adsorption performances, PM showed the outstanding adsorption capacities on Pb2+ and Cu2+ ions regardless of dissolving in deionized water or simulated gastrointestinal digestive fluid. Furthermore, the results also showed that the pH, temperature and adsorbent dosage had certain impacts on the adsorption performances of PM on Pb2+ and Cu2+ ions.

Stability and biological activity enhancement of fucoxanthin through encapsulation in alginate/chitosan nanoparticles

A response surface methodology based on the Box-Behnken design was employed to develop fucoxanthin (FX) delivery nanocarrier from alginate (ALG) and chitosan (CS). The FX-loaded ALG/CS nanoparticles (FX-ALG/CS-NPs) were fabricated using oil-in-water emulsification and ionic gelation. The optimal formulation consisted of an ALG:CS mass ratio of 0.015:1, 0.71 % w/v Tween™ 80, and 5 mg/mL FX concentrations. The resulting FX-ALG/CS-NPs had a size of 227 ± 23 nm, a zeta potential of 35.3 ± 1.7 mV, and an encapsulation efficiency of 81.2 ± 2.8 %. These nanoparticles exhibited enhanced stability under simulated environmental conditions and controlled FX release in simulated gastrointestinal fluids. Furthermore, FX-ALG/CS-NPs showed increased in vitro oral bioaccessibility, gastrointestinal stability, antioxidant activity, anti-inflammatory effect, and cytotoxicity against various cancer cells. The findings suggest that ALG/CS-NPs are effective nanocarriers for the delivery of FX in nutraceuticals, functional foods, and pharmaceuticals.

The Impact of Simulated Gastrointestinal Fluid: Viscosity, Surface Tension and Ph on Dissolution and Rheology Assessment of Viscosity on Two Commercial Products of Candesartan Cilexetil

The Impact of Simulated Gastrointestinal Fluid: Viscosity, Surface Tension and Ph on Dissolution and Rheology Assessment of Viscosity on Two Commercial Products of Candesartan Cilexetil

Green and single-step simultaneous composite starch aerogel formation-high bioavailability curcumin particle formation

The high porosity and specific surface area of aerogels offer an ideal platform for loading bioactive molecules. In the present study, the microstructure of the bio-based starch aerogels was modulated by the incorporation of chitosan. The starch hydrogel precursors were prepared from high amylose corn starch in the presence of 0, 0.50, and 0.75 wt% chitosan. Afterward, a green single-step simultaneous aerogel formation-curcumin deposition method was applied to impregnate curcumin into the aerogels through supercritical carbon dioxide (SC-CO2) drying technology. Composite starch/chitosan aerogels showed a more open porous structure and lighter weight than the neat starch counterpart. Confocal microscopy and fluorescence spectroscopy analysis confirmed curcumin molecules' attachment to the aerogels' hydrophobic cavities. The impregnation capacity was 24–27 mg curcumin per gram of aerogel depending on the composition of the aerogels. The loading of curcumin in the aerogels significantly enhanced the bioaccessibility of curcumin in the simulated gastrointestinal fluid by almost 30-fold when compared to the unloaded curcumin. Furthermore, the bioaccessibility of the curcumin loaded in starch-chitosan composite aerogels was higher than that in neat starch aerogels. While unloaded curcumin showed an undetectable intestinal Caco-2 cell transportation, curcumin-loaded aerogels revealed a cumulative curcumin passing of 0.15–0.23 μg/mL.

Synergistic antibacterial effect of the pistachio green hull extract-loaded porphysome decorated with 4-nitroimidazole against bacteria

‘Active targeting’ refers to modifying a nanocarrier’s surface with targeting ligands. This study introduced an efficient approach for immobilizing imidazole-based drugs onto the metallated-porphyrin complex within the porphysome nanocarrier. To enhance cellular and bacterial uptake, a Ni-porphyrin with a fatty acid tail was synthesized and placed in the bilayer center of DPPC, facilitating receptor-mediated endocytosis. The Ni-porphyrin in the head group of the Ni-porphyrin-tail was placed superficially in the polar region of the membrane. Spherical unilamellar vesicle formation (DPPC: Ni-porphyrin-tail 4:1 mole ratio), as metallo-porphysome, was achieved through supramolecular self-assembly in an aqueous buffer. These vesicles exhibited a diameter of 279 ± 7 nm and a zeta potential of −15.3 ± 2.5 mV, showcasing their unique cytocompatibility. Nitroimidazole was decorated on the surface of metallo-porphysomes and pistachio green hull extract (PGHE) was loaded into the carrier for synergistic activity against (E. coli) and (S. aureus) bacteria strains. The physicochemical properties of Nitroimidazole-porphysome-PGHE, including size, zeta potential, morphology, loading efficiency, and release profile under various pH and temperature conditions in simulated gastrointestinal fluids were characterized. This combination therapy prevented bacterial cell attachment and biofilm formation in Caco-2 cells, as colon epithelial cells. The remarkable benefit of this system is that it does not affect cell viability even at 0.5 mg/ml. This study demonstrates the potential of a new co-delivery system using biocompatible metallo-porphysomes to decrease bacterial infections.

Utilizing chitosan and pullulan for the encapsulation of Lactiplantibacillus plantarum ZJ316 to enhance its vitality in the gastrointestinal tract

Lactiplantibacillus plantarum ZJ316 has demonstrated effective alleviation of gastritis and colitis, making it crucial to improve its viability within the gastrointestinal tract. In this study, Chitosan (CS) and pullulan (PUL) encapsulated nanofibers of ZJ316 were prepared using electrospinning, considering both the synergistic effects of prebiotics and probiotics and their protective effects. We found that increasing the CS ratio resulted in elevated conductivity of the polymer solution, while decreasing viscosity and pH. Scanning electron microscopy showed that at a CS: PUL ratio of 1:135, polymer filaments were difficult to form, and nanofiber diameter decreased with higher CS content. X-ray diffraction analysis confirmed the miscibility of CS and PUL, while ATR-FTIR demonstrated the presence of hydrogen bonding interactions between the two materials. Thermal analysis indicated that an increased CS concentration improved the thermal stability of the nanofibers. Based on these findings, the optimal CS:PUL ratio for electrospinning was determined to be 1:60. Encapsulation of ZJ316 in the nanofibers significantly enhanced its survival rate in simulated gastrointestinal fluid compared to free bacteria, with survival rates of 87.24 % (gastric) and 79.71 % (intestinal), respectively. This study provides valuable insights for the development of probiotic functional foods.

Nano-encapsulation of EGCG in dextran 70-stabilized chitosan/SDS nanoparticles: Characterization, permeability behavior and oral bioavailability

Epigallocatechin gallate (EGCG) declares massive health benefits, while poor oral absorption and susceptibility to oxidation and degradation constrained clinical applications. EGCG-encapsulated chitosan/SDS nanoparticles coated with dextran 70（EDCSNs）were here prepared by ionic interaction. The nano-formulations stabilized by dextran 70 presented sizes less than <200 nm, > 30 mV zeta potential, excellent dispersion action and higher encapsulation efficiency, which outdistanced pluronic F-68 as stabilizer. Interaction mechanism of EGCG, chitosan, dextran 70 and SDS in EDCSNs were through hydrogen bond, ion–dipole and electrostatic of opposite charge. Compared with EGCG, EDCSNs demonstrated a superior stability and retention ability with the pH-responsive protection EGCG against degradation under the simulated gastrointestinal fluids. Furthermore, EDCSNs emanated remarkably antioxidant activity and permeability through the intestinal epithelial barrier. Oral administration of nano-formulations in rats evidently increased the plasma Cmax and area under-the-curve 1.95-fold than naked EGCG. Results evidenced that EDCSNs, as a new delivery system, has great potential improvement the stability of EGCG and enhancement the oral absorption and bioavailability.