Proanthocyanidins modification of the mineralized collagen scaffold based on synchronous self-assembly/mineralization for bone regeneration.

Proteoglycans (PG) is crucial for regulating collagen formation and mineralization during bone tissue development. A wide variety of PG-modified collagen scaffolds have been proposed for bone engineering application to promote biological responses and work as artificial matrices that guide tissue regeneration. However, poor performance of theses biomaterials against infections has led to an unmet need for clinical prevention. Therefore, we utilized proanthocyanidins (PA) to simulate the functions of PG, including mediating the collagen assembly and intrafibrillar mineralization, to optimize scaffolds performance. The excellent antibacterial properties of PA can endow the scaffolds with anti-infection effects in the process of tissue regeneration. When PA was added during fibrillogenesis, the collagen fibrils appeared irregular aggregation and the mineralization degree was reduced. In contrast, the addition of PA after collagen self-assembly improved the latter's ability to act as a deposition template and remarkably promoted mineral ions infiltration, thus enhancing intrafibrillar mineralization. The PA-modified scaffold displayed a highly hydrophilicity behaviour and long-term resistance to degradation. The sustained release of PA effectively inhibited the activity of Staphylococcus aureus. The scaffold also showed excellent biocompatibility and improved bone regeneration in calvarial critical-size defect models. The application of PA enables a dual-function scaffold with favourable intrafibrillar mineralization and anti-bacterial properties for bone regeneration.

Influence of Natural Dentin Biomodification Agent on Push-Out Bond Strength and Nanoleakage of Self-Adhesive Resin Cement Luting of Glass-Fiber Posts.

OBJECTIVE: To evaluate the plant-derived compound lignin (LIG) as a pretreatment of intraradicular dentin in combination with EDTA on push-out bond strength (PBS) and nanoleakage of the glass fiber posts (GFPs) cemented using adhesive resin cement. MATERIAL AND METHODS: Twenty-eight human incisor roots were prepared for GFP cementation and divided based on dentin pretreatment: (1) CONTROL: no pretreatment, (2) EDTA: 17% EDTA for 3 min, (3) EDTA-LIG: 17% EDTA and 2% lignin for 3 min, (4) EDTA-PAC: 17% EDTA and 2% lignin for 3 min. The GFPs were cemented using the self-adhesive resin cement Multilink Speed. The roots (n = 7) were sectioned into 1 mm-thick discs and subjected to PBS testing after 1 week or 6 months. Nanoleakage was analyzed by SEM. Statistical analysis was performed using two-factor ANOVA and Tukey's test (p < 0.05). RESULTS: Higher PBS was identified for the CONTROL group (p < 0.001). After 6 months, the EDTA-LIG maintained the bond strength with a predominance of mixed failures, while the EDTA-PAC, EDTA, and CONTROL groups showed reduction of bond strength, with a predominance of adhesive failures along with severe silver infiltration in the interface. CONCLUSION: LIG associated with EDTA as a pretreatment for intraradicular dentin shows significant potential for attaining stable bond strength and interfacial integrity of self-adhesive resin cement to intraradicular dentin.

Proanthocyanidin Regulates NETosis and Inhibits the Growth and Proliferation of Liver Cancer Cells - In Vivo, In Vitro and In Silico Investigation.

Liver cancer ranks third in global cancer-related mortality, with about 700,000 deaths recorded yearly, making it one of the most common cancers worldwide. Even though prognoses differ according to the severity of the diseases, many patients now exhibit an increased life cycle since the implementation of chemotherapy. In the current study, we investigated the effect of proanthocyanidin ‒a polyphenol molecule found in many plants‒ on the proliferation and invasion of liver cancer cells. In particular, we determined the effect of proanthocyanidin on the serum levels of four strategic liver cancer target, TNFα, IL-6, cfDNA, and IL-1ß. Further molecular insight on the inhibitory mechanism of proanthocyanidin against TNFα, IL-6, and IL-1ß was obtained via molecular docking, molecular dynamics simulations and binding free energy calculations. Results showed that proanthocyanidin inhibited the growth of HepG2 and HEP3B cells, and effectively reduced clonogenic survival and invasion potential when compared to control cells. Proanthocyanidin was also found to suppress the expression of Bcl-2 (26 kDa) protein in HepG2 cells, while increasing the expression of Bax (21 kDa). Molecular dynamics (MD) and thermodynamic binding free energy calculations showed that proanthocyanidin maintained stable binding within the active site of target proteins across the entire 100 ns MD simulation period, and its binding affinity outscored respective control molecules.In conclusion, the multifaceted analysis showcased in this study demonstrated promising anti-cancer effect of proanthocyanidin on HepG2 and HEP3B cancer cells, highlighting its potential as a viable liver cancer therapeutic alternative.

AIM/NBO Analysis of the Geminal Coupling Constants in the Stabilization of A-Type Dimeric Proanthocyanidin: Angular Dependence.

The angular dependence of the indirect short-range spin-spin coupling constants (SSCC), the geminal J ( C 3 , C 1 ' ) $$ J\left({C}_3,{C}_{1^{\prime }}\right) $$ , J ( O 1 , O ) $$ J\left({O}_1,O\right) $$ , and J ( O , C 1 ' ) $$ J\left(O,{C}_{1^{\prime }}\right) $$ in A-type dimeric proanthocyanidin, was investigated using density functional theory. We studied the rotation of ring B around the C 2 - C 1 ' $$ {C}_2\hbox{--} {C}_{1^{\prime }} $$ bond. Therefore, we calculated hyperconjugative charge transfers and bond polarizations within the natural bond orbital (NBO) approach, performing a topological study based on Bader's theory, AIM (atoms in molecules), and analyzing the angular dependence of AIM/NBO parameters. The results describe a relationship between the geminal coupling that changes with angular variation and NBO charge transfers to the bonds involved in the coupling pathways that can explain the behavior of the former property. Based on AIM/NBO data, inductive and mesomeric effects were described and quantified, showing a clear correlation with the stabilization of the structure, demonstrating a resonance-assisted inductive effect. We also set out strong hyperconjugative interactions (anomeric effect) involving nonbonding electron pairs of oxygen atoms. This analysis of coupling constants supports previous models by other authors and shows the application in this particular case. Moreover, the SSCCs studied herein are used for identifying stable structures and conformational search analysis of flavonoids. Finally, our results show the relationship between SSCCs and the structure stabilization and charge delocalization effects.

Development and evaluation of fermented milk with Lactobacillus acidophilus added to concentrated cranberry (Vaccinium macrocarpon) juice with the potential to minimize the recurrence of urinary tract infections.

Repeated urinary tract infections affect many people worldwide. A potential strategy to reduce the incidence of these infections is to consume probiotics and cranberry fruit regularly. In this context, this study aims to prepare fermented milk with Lactobacillus acidophilus La-5 added with concentrated cranberry juice in two concentrations (5 and 10 %, corresponding to C1 and C2 samples, respectively) and evaluate different technological aspects of the samples after production and during storage, and comparing with the control sample (C). The juice had pH 1.91, 70.09 % of solids, and total proanthocyanidins and A-type proanthocyanidins (PACs) values of 117.03 mg/100 g and 16.38 mg/100 g, respectively. The higher the juice content added to the product, the higher the acidity (1.4 and 2.6 g of lactic acid in 100 g, corresponding to C1 and C2 on day 1 (D1), respectively), the total proanthocyanidin content (1.96 and 4.01 mg/100 g on D1; and 1.31 and 3.05 mg/100 g on day 28 of storage (D28), corresponding to C1 and C2, respectively) and A-type proanthocyanidin (0.56 and 1.26 mg/100 g in Day 1; and 0.54 and 1.19 mg/100 g in D28, corresponding to C1 and C2, respectively), higher the values of the color parameters (L*a* and C*), and lower pH value, probiotic viability, and sensory acceptance. Furthermore, the rheological parameters demonstrated a stronger protein network due to the addition of cranberry. The new formulations, including samples C1 and C2, are alternatives as functional products, which regular consumption probably has the potential to minimize the recurrence of urinary tract infections.

The molecular basis of flavonoid biosynthesis response to water, light, and temperature in grape berries.

Flavonoids, including proanthocyanidins (PAs), anthocyanins and flavonols are essential secondary metabolites that contribute to the nutritional value and sensory quality of grape berry and red wine. Advances in molecular biology technology have led to substantial progress in understanding the regulation of flavonoid biosynthesis. The influence of terroir on grape berries and wine has garnered increasing attention, yet its comprehensive regulatory network remains underexplored. In terms of application, environmental factors such as water, light, and temperature are more easily regulated in grapevines compared to soil conditions. Therefore, we summarize their effects on flavonoid content and composition, constructing a network that links environmental factors, hormones, and metabolites to provide a deeper understanding of the underlying mechanisms. This review enriches the knowledge of the regulatory network mechanisms governing flavonoid responses to environmental factors in grapes.

Electron beam irradiation coupled ultrasound-assisted natural deep eutectic solvents extraction: A green and efficient extraction strategy for proanthocyanidin from walnut green husk.

Proanthocyanidin (PAC) is recognized as a potent natural antioxidant that prevents various diseases. As societal awareness increases, eco-friendly and efficient natural product extraction technologies are gaining more attention. In this study, an electron beam irradiation (EBI) coupled with ultrasound-assisted natural deep eutectic solvents (NADES) extraction method was developed to enable the green and highly efficient extraction of PAC from walnut green husk (WGH). NADES, prepared with choline chloride and ethylene glycol, demonstrated excellent extraction capacity and storage stability for PAC. Molecular dynamics simulations elucidated the high compatibility between NADES and PAC, attributed mainly to a higher SASA value (207.85 nm2), a greater number of hydrogen bonds (330.99), an extended hydrogen bonding lifetime (4.54 ps), and lower inter-molecular interaction energy. Based on these findings, the optimal conditions (13 kGy EBI, 42 mL/g liquid-solid ratio, 38 °C extraction temperature, 70 min extraction time) resulted in a maximum PAC extraction yield of 56.34 mg/g. Notably, this yield was 32.93 % higher than that observed in samples not treated with EBI and ultrasound-assisted extraction (UAE). Analysis of tissue morphology, extract functional groups and thermal behavior suggested a possible mechanism for the synergistically enhanced PAC extraction by the EBI-NADES-UAE method. Additionally, the PAC extracted using the NADES by the EBI coupled with ultrasound-assisted method exhibited outstanding antioxidant activity (comparable to Vc), digestive enzyme inhibition (IC50: 17-0.61 mg/mL), and anti-glycation capacity (IC50: 86.49 µg/mL). Overall, this work provided a green and efficient strategy for PAC extraction from WGH, elucidated the extraction mechanism and bioactivities, and offered valuable insights for potential industrial applications.

Promotion effect of proanthocyanidin on dentin remineralization via the polymer induced liquid precursor process.

Proanthocyanidin (PA) has demonstrated promise as a dental biomodifier for maintaining dentin collagen integrity, yet there is limited evidence regarding its efficacy in dentin repair. The aim of this study was to investigate the effect of PA on dentin remineralization through the polymer induced liquid precursor (PILP) process, as well as to assess the mechanical properties of the restored dentin. Demineralized dentin was treated with a PA-contained remineralization medium, resulting in the formation of PA-amorphous calcium phosphate (ACP) nanoparticles via the PILP process. The kinetics and microstructure of remineralized dentin were examined through the use of Fourier transform infrared spectroscopy(FTIR), attenuated total reflectance-FTIR, scanning electron microscopy, transmission electron microscopy. The results showed that the application of PA facilitated the process of dentin remineralization, achieving completion within 48 h, demonstrating a notable reduction in time required. Following remineralization, the mechanical properties of the dentin exhibited an elastic modulus of 15.89 ± 1.70 GPa and a hardness of 0.47 ± 0.08 GPa, which were similar to those of natural dentin. These findings suggest that combining PA with the PILP process can promote dentin remineralization and improve its mechanical properties, offering a promising new approach for dentin repair in clinical practice.

Metabolic basis for superior antioxidant capacity of red-fleshed peaches.

Peach fruit is an important natural source of phenolic compounds that are well-known to have health benefits, but their metabolic basis remain elusive. Here, we report on phenolic compounds accumulation and antioxidant activity of ripe fruits in peach. A considerable variation in phenolic compounds content was observed among peach germplasm, with significantly higher levels detected in red-fleshed peaches compared to non-red-fleshed peaches. Antioxidant activity of crude extracts from ripe fruits showed significant differences among peach germplasm, with red-fleshed peaches having the strongest antioxidant activity. Intriguingly, it was observed that total phenolics instead of anthocyanins were strongly associated with antioxidant activity. Phenolic compounds content and antioxidant activity showed dynamic changes throughout fruit development, and these were much higher in the peel than in the flesh. Metabolomic analysis unveiled a coordinated accumulation of anthocyanins as well as key components of flavonoids and phenolic acids, which endows red-fleshed peaches with superior antioxidant activity.

Exploring the Interactions between Plant Proanthocyanidins and Thiabendazole: Insights from Isothermal Titration Calorimetry.

Anthelmintic resistance in gastrointestinal nematodes produces substantial challenges to agriculture, and new strategies for nematode control in livestock animals are called for. Natural compounds, including tannins, with proven anthelmintic activity could be a functional option as structurally diverse complementary compounds to be used alongside commercial anthelmintics. However, the dual use of two anthelmintic components requires an understanding of the pharmacological effects of the combination, while information concerning the interactions between plant-based polyphenols and commercial anthelmintics is scarce. We studied the direct interactions of proanthocyanidins (PAs, syn. condensed tannins) and a commercial anthelmintic thiabendazole, as a model substance of benzimidazoles, by isothermal titration calorimetry (ITC). Our results show evidence of a direct interaction of an exothermic nature with observed enthalpy changes ranging from 0 to -30 kJ/mol. The strength of the interaction between PAs and thiabendazole is mediated by structural characteristics of the PAs with the strongest positive correlation originating from the presence of galloyl groups and the increased degree of polymerization.

Halogenated Analogs to Natural A-Type Proanthocyanidins: Evaluation of Their Antioxidant and Antimicrobial Properties and Possible Application in Food Industries.

A description of new antimicrobial agents suitable for food industries has become necessary, and natural compounds are being considered as promising sources of new active derivatives to be used with the aim of improving food safety. We have previously described desirable antimicrobial and antibiofilm activities against foodborne bacteria by analogs to A-type proanthocyanidins (PACs) with a nitro (NO2) group at carbon 6 of the A-ring. We report herein the synthesis of eight additional analogs with chloro and bromo atoms at the A-ring and the systematic study of their antimicrobial and antioxidant activities in order to evaluate their possible application as biocides or food preservatives, as well as to elucidate new structure-activity relationships. The results from this study show that halogenated analogs to natural A-type proanthocyanidins rise above the nitro derivatives previously reported in their antimicrobial activities. Gram-positive bacteria are the most sensitive to all the analogs and combinations assayed, showing MICs from 10 to 50 µg/mL in most cases, as well as reductions in biofilm formation and the disruption of preformed biofilms of at least 75%. Some structure-activity relationships previously described have also been corroborated. Analogs with just one OH group at the B-ring show better antimicrobial activities than those with two OH groups, and those analogs with two or three OH groups in the whole structure are more active than those with four OH groups. In addition, the analogs with two OH groups at the B-ring and chloro at the A-ring are the most effective when antibiofilm activities are studied, especially at low concentrations.

Enzyme-esterified grape seed proanthocyanidin derivatives as novel lipid-lowering agents.

Grape seed proanthocyanidin (GSP), as a natural antioxidant, has great potential to be developed into a lipid-lowering agent, but its low lipophilicity and stability greatly limit its application. In this study, an enzymatic esterification strategy was developed to introduce fatty acid chains into GSP, resulting in the successful synthesis of a series of new GSP derivatives. The results showed that up to 85% conversion of GSP and 35% TAG inhibition rate of GSP derivatives were achieved. The structures of GSP derivatives were identified by UPLC-MS/MS, and seven derivatives were confirmed as catechin-3'-O-laurate, epicatechin-3'-O-laurate, epicatechin gallate-3″,5″-di-O-laurate, epicatechin gallate-3',3″,5″-tri-O-laurate, procyanidin B1-3',3″-di-O-laurate, procyanidin B2-3',3″-di-O-laurate and procyanidin C1-3',3″,3‴-tri-O-laurate by NMR. GSP derivatives exhibited higher inhibitory effects on lipid accumulation, intracellular TAG and TC than parent GSP. These results indicate that GSP derivatives have potential as lipid-lowering agents for utilization in the food industry.

Proanthocyanidin alleviates testicular torsion/detorsion-induced ischemia/reperfusion injury in rats.

Testicular torsion is an urological emergency and can lead to ischemia damage and testicular loss if not diagnosed in time. Proanthocyanidin is reported to have anti-inflammatory and antioxidant properties. The current study aimed to examine the possible effects of proanthocyanidin (P) on the testis in torsion/detorsion (T/D)-induced testicular ischemia/reperfusion (I/R) injury in rats. Forty rats were divided into four groups (n=10 for each): sham-operated (sham), I/R, I/R + P100 (100 mg/kg, 30 min before torsion), and I/R + P200 (200 mg/kg, 30 min before torsion). Testicular T/D was performed on the left testicle by 3 hours of torsion at 720° clockwise, followed by 3 hours of detorsion. In the I/R group, an increase in malondialdehyde (MDA) levels and a decrease in glutathione (GSH), vitamin C (Vit C), glutathione peroxidase (GPx), glucose-6-phosphate dehydrogenase (G6PD) values were determined compared to the sham group (p<0.001). Moreover, an increase in the expression of cleaved caspase-3 and Bcl2-associated X protein (Bax), a decrease in the expression of B-cell lymphoma 2 (Bcl-2) and proliferating cell nuclear antigen (PCNA) were detected in the I/R group (p<0.001). Histopathologically, it was determined that the Johnsen and Cosentino scores of the testicles were irregular in the I/R group (p<0.001). Proanthocyanidin treatment caused a decrease in MDA, cleaved caspase-3 and Bax levels and an increase in GSH, Vit C, GPx, G6PD, Bcl-2 and PCNA values. Additionally, Johnsen and Cosentino rearranged the scores. The present findings revealed the protective and curative effects of proanthocyanidin in organ damage due to testicular torsion/detorsion-induced ischemia/reperfusion with their antioxidative and antiapoptotic properties.

Addressing astringency of grape seed extract by covalent conjugation with lupin protein.

Astringency of phenolic-rich foods is a key tactile perception responsible for acceptability/rejection of plant extracts as ingredients in formulations. Covalent conjugation of phenolic extracts with plant proteins might be a promising strategy to control astringency, but suffers from a lack of mechanistic understanding from the lubrication point of view. To shed light on this, this ex vivo study evaluated the effect of conjugation of a phenolic grape seed extract (GSE) with legume protein (lupin, LP) on tribological and surface adsorption performance of GSE in the absence and presence of human saliva (ex vivo). Tribological results confirmed GSE had an inferior lubrication capacity as compared to LP. The lubrication performance of LP-GSE dispersions was comparable to their corresponding LP dispersion (p > 0.05) when covalently conjugated with LP (LP-GSE) with increasing LP:GSE ratio up to 1:0.04 w/w and at a specific degree of conjugation (DC: 2%). Tribological and surface adsorption measurements confirmed the tendency of GSE to interact with human saliva (ex vivo, n = 17 subjects), impairing the lubricity of salivary films. The covalent bonding of LP to GSE hindered GSE's interaction with human saliva, implying the potential influence of covalent conjugation on attenuating astringency. LP appeared to compete with human saliva for surface adsorption and governed the lubrication behaviour in LP-GSE dispersions. Findings from this study provide valuable knowledge to guide the rational design of sustainable, functional foods using conjugation of phenolics with plant proteins to incorporate larger proportions of health-promoting phenolics while controlling astringency, which needs validation by sensory trials.

Genome-wide identification of R2R3-MYB family in Eriobotrya japonica and functional analysis of EjMYB5 involved in proanthocyanidin biosynthesis.

Loquat (Eriobotrya japonica Lindl.) is a popular fruit and medicinal plant. Proanthocyanidins (PAs), as one of the main types of flavonoids, are the key components of loquat fruit quality and medicinal properties. However, the identification of transcription factors (TFs) involved in PA accumulation in loquat remains limited. R2R3-MYB TFs play key regulatory role in PA accumulation in plants. In this study, 190 R2R3-MYB TFs were identified in loquat genome. Combined with transcriptome data, R2R3-MYB TF EjMYB5 involved in PA accumulation in loquat was isolated. EjMYB5 was transcriptional activator localized to nucleus. Expression of EjMYB5 was closely related to PA accumulation in loquat fruits. Heterogenous overexpression of EjMYB5 in tomato (Solanum lycopersicum) inhibited anthocyanin accumulation and promoted PA accumulation. Additionally, transient overexpression of EjMYB5 in tobacco (Nicotiana benthamiana) leaves promoted PA accumulation by upregulating flavonoid biosynthesis genes (NtDFR, NtANS, and NtLAR). Transcriptome analysis of EjMYB5-overexpressing tomato fruits suggested that EjMYB5 was involved in several biological pathways, including lipid metabolism, MAPK signaling, phenylpropanoid biosynthesis, and flavonoid biosynthesis. Collectively, our findings provided basic data for further analysis the function of R2R3-MYB TFs in loquat, and revealed that EjMYB5 functioned as PA accumulation in loquat.

The HD-ZIP IV transcription factor GLABRA2 acts as an activator for proanthocyanidin biosynthesis in Medicago truncatula seed coat.

Proanthocyanidins (PAs), a group of flavonoids, are found in leaves, flowers, fruits, and seed coats of many plant species. PAs are primarily composed of epicatechin units in the seed coats of the model legume species, Medicago truncatula. It can be synthesized from two separate pathways, the leucoanthocyanidin reductase (MtLAR) pathway and the anthocyanidin synthase (MtANS) pathway, which produce epicatechin through anthocyanidin reductase (MtANR). These pathways are mainly controlled by the MYB-bHLH-WD40 (MBW) ternary complex. Here, we characterize a class IV homeodomain-leucine zipper (HD-ZIP IV) transcription factor, GLABRA2 (MtGL2), which contributes to PA biosynthesis in the seed coat of M. truncatula. Null mutation of MtGL2 results in dark brown seed coat, which is accompanied by reduced PAs accumulation and increased anthocyanins content. The MtGL2 gene is predominantly expressed in the seed coat during the early stages of seed development. Genetic and molecular analyses indicate that MtGL2 positively regulates PA biosynthesis by directly activating the expression of MtANR. Additionally, our results show that MtGL2 is strongly induced by the MBW activator complexes that are involved in PA biosynthesis. Taken together, our results suggest that MtGL2 acts as a novel positive regulator in PA biosynthesis, expanding the regulatory network and providing insights for genetic engineering of PA production.

Grape Seed Proanthocyanidin Extract Attenuates Cafeteria-Diet-Induced Liver Metabolic Disturbances in Rats: Influence of Photoperiod.

This study investigated the influence of photoperiod (day length) on the efficacy of grape seed proanthocyanidin extract (GSPE) in mitigating metabolic disorders in obese rats fed a cafeteria diet. Rats were exposed to standard (L12), long (L18), or short (L6) photoperiods and treated with GSPE or vehicle. In the standard photoperiod, GSPE reduced body weight gain (50.5%), total cholesterol (37%), and triglycerides (34.8%), while increasing the expression of hepatic metabolic genes. In the long photoperiod, GSPE tended to decrease body weight gain, increased testosterone levels (68.3%), decreased liver weight (12.4%), and decreased reverse serum amino acids. In the short photoperiod, GSPE reduced glycemia (~10%) and lowered triglyceride levels (38.5%), with effects modified by diet. The standard photoperiod showed the greatest efficacy against metabolic syndrome-associated diseases. The study showed how day length affects GSPE's benefits and underscores considering biological rhythms in metabolic disease therapies.

Proanthocyanidin surface preconditioning of dental pulp stem cell spheroids enhances dimensional stability and biomineralization in vitro.

AIM: Lack of adequate mechanical strength and progressive shrinkage over time remain challenges in scaffold-free microtissue-based dental pulp regeneration. Surface collagen cross-linking holds the promise to enhance the mechanical stability of microtissue constructs and trigger biological regulations. In this study, we proposed a novel strategy for surface preconditioning microtissues using a natural collagen cross-linker, proanthocyanidin (PA). We evaluated its effects on cell viability, tissue integrity, and biomineralization of dental pulp stem cell (DPSCs)-derived 3D cell spheroids. METHODOLOGY: Microtissue and macrotissue spheroids were fabricated from DPSCs and incubated with PA solution for surface collagen cross-linking. Microtissue viability was examined by live/dead staining and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, with transverse dimension change monitored. Microtissue surface stiffness was measured by an atomic force microscope (AFM). PA-preconditioned microtissues and macrotissues were cultured under basal or osteogenic conditions. Immunofluorescence staining of PA-preconditioned microtissues was performed to detect dentin sialophosphoprotein (DSPP) and F-actin expressions. PA-preconditioned macrotissues were subjected to histological analysis, including haematoxylin-eosin (HE), alizarin red, and Masson trichrome staining. Immunohistochemistry staining was used to detect alkaline phosphatase (ALP) and dentin matrix acidic phosphoprotein 1 (DMP-1) expressions. RESULTS: PA preconditioning had no adverse effects on microtissue spheroid viability and increased surface stiffness. It reduced dimensional shrinkage for over 7 days in microtissues and induced a larger transverse-section area in the macrotissue. PA preconditioning enhanced collagen formation, mineralized nodule formation, and elevated ALP and DMP-1 expressions in macrotissues. Additionally, PA preconditioning induced higher F-actin and DSPP expression in microtissues, while inhibition of F-actin activity by cytochalasin B attenuated PA-induced dimensional change and DSPP upregulation. CONCLUSION: PA surface preconditioning of DPSCs spheroids demonstrates excellent biocompatibility while effectively enhancing tissue structure stability and promoting biomineralization. This strategy strengthens tissue integrity in DPSC-derived spheroids and amplifies osteogenic differentiation potential, advancing scaffold-free tissue engineering applications in regenerative dentistry.

Stability enhancement of proanthocyanidin-loaded liposomes via surface decoration with oxidized konjac glucomannan.

The stability enhancement of proanthocyanidin-loaded liposomes (PC-Lip) via surface decoration with oxidized konjac glucomannan (OKGM) was investigated. The encapsulation efficiency and drug loading capacity of OKGM-coated PC-Lip (OKGM-PC-Lip) rose significantly. The average size and PDI of OKGM-PC-Lip increased, while the zeta potential decreased compared to those of PC-Lip. PC-Lip membrane fluidity reduced after coating with OKGM. The morphology of OKGM-PC-Lip showed that OKGM "halo layer" was formed on the liposome surface. Hydrogen bonding played an indispensable role in the combination between OKGM and PC-Lip, and the phase transition temperature of PC-Lip slightly increased after coating with OKGM. The retention rate of OKGM-PC-Lip was higher than that of PC-Lip at extreme pH. In vitro release, no significant difference in cumulative release was detected between OKGM-PC-Lip and PC-Lip at gastric stage, while the cumulative release rate of OKGM-PC-Lip was remarkably lower than that of PC-Lip at intestinal stage. The antioxidant activity of OKGM-PC-Lip was notably higher than that of PC-Lip. These results suggested that the resistance of PC-Lip to external influences was fruitfully enhanced after coating with OKGM. Compared with other polysaccharides, OKGM-coated liposomes may be more promising and advantageous in functional foods due to the polysaccharide's benefits to human health.

Tannic acids and proanthocyanidins in tea inhibit SARS-CoV-2 variants infection.

The COVID-19 pandemic has caused hundreds million cases and millions death as well as continues to infect human life in the world since late of 2019. The breakthrough infection caused from mutation of SARS-CoV-2 is rising even the vaccinated population has been increasing. Currently, the severe threat posed by SARS-CoV-2 has been alleviated worldwide, and the situation has transitioned to coexisting with the virus. The dietary food with antiviral activities may improve to prevent virus infection for living with COVID-19 pandemic. Teas containing enriched phenolic ingredients such as tannins have been reported to be antitumor agents as well as be good inhibitors for coronavirus. This study developed a highly sensitive and selective ultra-high performance liquid chromatography-high resolution mass spectrometric method for quantification of tannic acids, a hydrolysable tannin, and proanthocyanidins, a condense tannin, in teas with different levels of fermentation. The in vitro pseudoviral particles (Vpp) infection assay was used to evaluate the inhibition activities of various teas. The results of current research demonstrate that the tannins in teas are effective inhibitors against infection of SARS-CoV-2 and its variants.