Human urine-derived stem cells in combination with polycaprolactone/gelatin nanofibrous membranes enhance wound healing by promoting angiogenesis.

BACKGROUND: Despite advancements in wound healing techniques and devices, new treatments are needed to improve therapeutic outcomes. This study aimed to evaluate the potential use of a new biomaterial engineered from human urine-derived stem cells (USCs) and polycaprolactone/gelatin (PCL/GT) for wound healing. METHODS: USCs were isolated from healthy individuals. To fabricate PCL/GT composite meshes, twin-nozzle electrospinning were used to spin the PCL and gelatin solutions in normal organic solvents. The morphologies and hydrophilicity properties of PCL/GT membranes were investigated. After USCs were seeded onto a PCL/GT, cell adhesion, morphology, proliferation, and cytotoxicity were examined. Then, USCs were seeded on a PCL/GT blend nanofibrous membrane and transplanted into rabbit full-thickness skin defects for wound repair. Finally, the effect of USCs condition medium on proliferation, migration, and tube formation of human umbilical vein endothelial cells (HUVECs) were performed in vitro. RESULTS: USCs were successfully isolated from urine samples and expressed specific mesenchymal stem cells markers and could differentiate into osteoblasts, adipocytes, and chondrocytes. PCL/GT membrane has suitable mechanical properties similar with skin tissue and has good biocompatibility. USCs-PCL/GT significantly enhanced the healing of full-thickness skin wounds in rabbits compared to wounds treated with PCL/GT membrane alone or untreated wounds. USCs-PCL/GT-treated wounds closed much faster, with increased re-epithelialization, collagen formation, and angiogenesis. Moreover, USCs could secrete VEGF and TGF-ß1, and USC-conditioned medium enhanced the migration, proliferation, and tube formation of endothelial cells. CONCLUSION: USCs in combination with PCL/GT significantly prompted the healing of full-thickness skin wounds in rabbits. USCs based therapy provides a novel strategy for accelerating wound closure and promoting angiogenesis.

Impact of thermal treatment on proanthocyanidin-pectin binary complexes: Insights from structural, rheological, antioxidant, and astringent properties.

In this study, the effects of thermal treatments on the structural, rheological, water mobility, antioxidant, and astringency properties of proanthocyanidin (PA)-pectin binary complexes were investigated. Thermal treatments (25, 63, or 85 °C) significantly decreased the particle size but increased the molecular weight of PA-pectin complexes, which indicated that heating altered the intermolecular and intramolecular interactions between PA and pectin. The thermal treatments reduced the apparent viscosity of both pectin and PA-pectin complexes, but the presence of proanthocyanidins (PAs) increased the apparent viscosity and water mobility of the PA-pectin complexes. Antioxidant activity analysis showed that the presence of pectin slightly reduced the antioxidant activity of the PAs, but there were no significant changes in the total phenolic content and antioxidant activity after thermal treatment. Finally, we found that pectin reduced the astringency of the PAs by forming PA-pectin complexes. Moreover, the thermal treatments also significantly reduced the astringency of the PA-pectin complexes.

Effects of pile fermentation on the physicochemical, functional, and biological properties of tea polysaccharides.

This study investigated the influence of pile fermentation on the physicochemical, functional, and biological properties of tea polysaccharides (TPS). Results indicated that the extraction yield, uronic acid content, and polyphenol content of TPS greatly increased from 1.8, 13.1 and 6.3 % to 4.1, 27.9, and 7.8 %, respectively, but the molecular weight markedly decreased from 153.7 to 76.0 kDa after pile fermentation. Additionally, the interfacial, emulsion formation, and emulsion stabilization properties of TPS were significantly improved after pile fermentation. For instance, 1.0 wt% TPS isolated from dark tea (D-TPS) can fabricate 8.0 wt% MCT oil-in-water nanoemulsion (d32 ≈ 159 nm) with potent storage stability. Moreover, the antioxidant and α-glucosidase inhibitory activities of D-TPS was higher than that of TPS isolated from sun-dried raw tea (R-TPS). Overall, this study indicated that pile fermentation markedly affected the physicochemical and structural characteristics of TPS, thereby improving their functional and biological properties.

Enhancement of lycopene bioaccessibility in tomatoes using excipient emulsions: Effect of dark tea polysaccharides.

This study fabricated a novel excipient emulsion by adding dark tea polysaccharides to improve the bioaccessibility of lycopene from tomatoes. Results indicated that addition of tea polysaccharides greatly increased the antioxidant activity of excipient emulsions. Additionally, tea polysaccharides markedly improved the physical stability of excipient emulsion when being mixed with tomato puree and passing through a simulated gastrointestinal tract, contributing to an increase in electrostatic and steric repulsion between the droplets. Besides, certain amount of tea polysaccharides (0.05 - 0.2 wt%) could increase the rate and extent of lipid digestion in tomato-emulsion mixtures. Finally, lycopene bioaccessibility was significantly increased (from 16.95 % to 26.21 %) when 0.1 wt% tea polysaccharides were included, which was mainly ascribed to the ability of tea polysaccharides to increase lipid digestion and reduce carotenoid oxidation within the gastrointestinal tract. These results suggest that well-designed excipient emulsions may increase carotenoids bioavailability in the complex food matrices.

Reinforcing alginate matrixes by tea polysaccharide conjugates or their stabilized nanoemulsion for probiotics encapsulation: Characterization, survival after gastrointestinal digestion and ambient storage.

Tea polysaccharide conjugates (TPC) were used as fillers in the form of biopolymer or colloidal particles (TPC stabilized nanoemulsion, NE) for reinforcing alginate (ALG) beads to improve the probiotic viability. Results demonstrated that adding TPC or NE to ALG beads significantly enhanced the gastrointestinal viability of encapsulated probiotics when compared to free cells. Moreover, the survivability of free and ALG encapsulated probiotics markedly decreased to 2.03 ± 0.05 and 2.26 ± 0.24 log CFU/g, respectively, after 2 weeks ambient storage, indicating pure ALG encapsulation had no effective storage protective capability. However, adding TPC or NE could greatly enhance the ambient storage viability of probiotics, with ALG + NE beads possessing the best protection (8.93 ± 0.06 log CFU/g) due to their lower water activity and reduced porosity. These results suggest that TPC and NE reinforced ALG beads have the potential to encapsulate, protect and colonic delivery of probiotics.

Emerging roles of platelet concentrates and platelet-derived extracellular vesicles in regenerative periodontology and implant dentistry.

Platelet concentrates (PCs) are easily obtained from autogenous whole blood after centrifugation and have evolved through three generations of development to include platelet-rich plasma, platelet-rich fibrin, and concentrated growth factor. Currently, PCs are widely used for sinus floor elevation, alveolar ridge preservation, periodontal bone defects, guided bone regeneration, and treatment of gingival recession. More recently, PCs have been leveraged for tissue regeneration to promote oral soft and hard tissue regeneration in implant dentistry and regenerative periodontology. PCs are ideal for this purpose because they have a high concentration of platelets, growth factors, and cytokines. Platelets have been shown to release extracellular vesicles (P-EVs), which are thought to be essential for PC-induced tissue regeneration. This study reviewed the clinical application of PCs and P-EVs for implant surgery and periodontal tissue regeneration.

TiO2 nanoparticles negatively impact the bioavailability and antioxidant activity of tea polyphenols.

This study was to investigate the influence of TiO2 nanoparticles (NPs) on the stability, bioavailability, and antioxidant activity of co-ingested tea polyphenols extract using an in vitro digestion model. The tea polyphenol contents decreased significantly after addition of 0.5 % (w/w) TiO2 NPs. The gallocatechin gallate level decreased the most, changing from 101.9 to 27.2 µg/mL (about 73.3%). The TiO2 NPs also reduced the bioavailability of the tea polyphenols in a dose-dependent manner, which was ascribed to the formation of large polyphenol-TiO2 NP complex aggregates that could not pass through the pores in the dialysis tube used to simulate the gut wall. Additionally, the TiO2 NPs decreased the antioxidant activity of the tea polyphenols within the simulated gastrointestinal tract. In summary, our results show that high levels of TiO2 NPs (but within the current legal limits in many countries) may negatively impact the bioavailability and bioactivity of polyphenols in foods.

Physicochemical characterization, emulsifying and antioxidant properties of the polysaccharide conjugates from Chin brick tea (Camellia sinensis).

Tea polysaccharide conjugate fractions (TPCs) with different molecular weights (TPC-40, TPC-60, and TPC-80, MW = 1355 to 204 kDa) were prepared from Chin brick tea using graded alcohol precipitation. The physiochemical and functional properties of TPCs were investigated. Results showed that TPC-80 (204 kDa) had the highest antioxidant activity attributed to its higher phenolic and theabrownin contents. Moreover, this fraction had the highest surface pressure (16.2 ± 0.9 mN/m), but the lowest interfacial dilatational modulus (30.3 ± 2.2 mN/m) than TPC-40 (1355 kDa) and TPC-60 (955 kDa). As a result, TPC-80 had the highest emulsifying activity but the lowest emulsion stabilizing properties due to its fastest adsorption kinetics but the relatively thin interfacial coating on the oil droplets. Overall, our results indicate that the chemical compositions and structural characteristics of TPCs significantly impact their functional attributes. TPCs have the potential to be a novel natural antioxidant emulsifier in food industry.

Impact of Polyphenol Interactions with Titanium Dioxide Nanoparticles on Their Bioavailability and Antioxidant Activity.

Titanium dioxide is widely utilized as a pigment in the food industry to enhance the whiteness or brightness of foods and beverages. The powdered forms of titanium dioxide used as food ingredients contain a substantial fraction of nanoparticles (d < 100 nm), which may have adverse effects on human health. This is a model study that investigated the molecular interactions between TiO2 nanoparticles and selected polyphenols, as well as their influence on the in vitro bioavailability and antioxidant activity of the polyphenols. Our results showed that the chemical structure of polyphenols significantly influenced their binding affinity to TiO2 nanoparticle surfaces, with those possessing vicinal trihydroxy groups having the highest binding affinities. The presence of TiO2 nanoparticles was shown to reduce the bioavailability of polyphenols using an in vitro digestion model. This effect was mainly ascribed to the formation of large TiO2 nanoparticle-polyphenol complex agglomerates that could not pass through the pores in the dialysis tube used to simulate the epithelium layer. Additionally, the binding of polyphenols to the surfaces of TiO2 nanoparticles reduced their antioxidant activity. This study provides valuable insights into the impact of inorganic nanoparticles on the bioavailability and bioactivity of polyphenols.

Titanium Dioxide Nanoparticles Do Not Adversely Impact Carotenoid Bioaccessibility from Tomatoes Consumed with Different Nanoemulsions: In Vitro Digestion Study.

Titanium dioxide (TiO2) is used as an additive to whiten some foods and beverages that contain lipid nanoparticles. We therefore investigated the combined influence of TiO2 and lipid nanoparticles on carotenoid bioaccessibility from tomatoes. TiO2 nanoparticles ( d = 167 nm) were combined with nanoemulsions ( d ≈ 150 nm) stabilized by various emulsifiers: Tween 80, whey protein, or sodium caseinate. The mixed systems were then mixed with tomatoes and passed through a simulated gastrointestinal tract (GIT). The emulsifier type significantly influenced carotenoid bioaccessibility ( p < 0.05), mainly because of differences in the ability of the emulsifier-coated lipid droplets to extract carotenoids from tomatoes and form mixed micelles. TiO2 addition did not impact lipid digestion and carotenoid bioaccessibility ( p > 0.05). These results suggested that carotenoid bioaccessibility was not influenced by TiO2 addition but did depend on the type of emulsifier used to stabilize lipid nanoparticles.

Comparison of phytochemical profiles and antiproliferative activities of different proanthocyanidins fractions from Choerospondias axillaris fruit peels.

Epidemiological studies had indicated that the incidence of colorectal cancer is inversely correlated to the consumption of proanthocyanidins (PAs). In this study, five PAs fractions isolated from Choerospondias axillaris fruit peels with different mean degree of polymerization (mDP) were characterized and their antiproliferative effects on Caco-2 cells were investigated. MALDI-TOF-MS results indicated that PAs fractions were composed of procyanidins with DP up to 13-mers. All PAs fractions induced dose and time-dependent reductions of Caco-2 cell viability. The IC50 values of PAs fractions with increasing mDP were 240 ±â€¯16.0, 143 ±â€¯9.53, 87.0 ±â€¯3.55, 44.3 ±â€¯4.89, and 42.8 ±â€¯2.20 µg/mL after 24 h incubation, respectively. The observed reduction in Caco-2 cell viability was due to apoptosis via the activation of caspase-9, caspase-3, caspase-8 and the elevation of intracellular ROS generation. Moreover, the extent of the reduction in cell viability after exposure to PAs fractions was positively correlated with their mDP and galloylation. These results indicate that Choerospondias axillaris peel is a potential source of natural chemopreventive agents for the treatment of colorectal cancer.

Impact of Titanium Dioxide on the Bioaccessibility of ß-Carotene in Emulsions with Different Particle Sizes.

Commercial, titanium dioxide (TiO2) ingredients used as color additives (E171) in foods and beverages contain an appreciable fraction of particles in the nanoscale range. At present, little information is available regarding the potential impact of food-grade TiO2 nanoparticles on the gastrointestinal fate of co-ingested bioactives, such as nutraceuticals. In this study, the impact of TiO2 on the bioaccessibility of ß-carotene solubilized in model food emulsions was investigated using a simulated gastrointestinal tract model. Raman spectroscopy showed that there was no charge transfer between ß-carotene and TiO2 but that some ß-carotene absorbed to the surface of TiO2 particles. The initial particle size of the food emulsion did not significantly affect ß-carotene bioaccessibility, probably because the same amount of free fatty acids (FFAs) was released by the end of digestion. The addition of TiO2 at levels typically found in foods also had no significant impact on ß-carotene bioaccessibility and FFA release, which suggested that this type of inorganic particle does not interfere with the gastrointestinal fate of these lipophilic bioactive agents. This information is important for ensuring the safety of inorganic nanoparticle utilization within the food industry.

Induction of Osteogenic Differentiation of Human Adipose-Derived Stem Cells by a Novel Self-Supporting Graphene Hydrogel Film and the Possible Underlying Mechanism.

Graphene and its derivatives have received increasing attention from scientists in the field of biomedical sciences because of their unique physical properties, which are responsible for their interesting biological functions. With a range of extraordinary properties such as high surface area, high mechanical strength, and ease of functionalization, graphene is considered highly promising for application in bone tissue engineering. Here, we examined the effect of using a self-supporting graphene hydrogel (SGH) film to induce the osteogenic differentiation of human adipose-derived stem cells (hADSCs). In comparison to conventional graphene and carbon fiber films, the SGH film had higher mechanical strength and flexibility. Moreover, we found that the SGH film was nontoxic and biocompatible. Of particular interest is the fact that the film alone could stimulate the osteogenic differentiation of hADSCs, independent of additional chemical inducers. Such effects are stronger for the SGH film than for graphene or carbon fiber films, although the induction capacity of the SGH film is not as high as that of the osteogenic-induced medium. The excellent osteoinductivity of the SGH film is closely related to its remarkable physical properties that include specific nanostructures, surface morphology, strong cell adherence, reasonable surface hydrophilicity, and high protein absorption.