Development of quercetin-loaded electrospun nanofibers through shellac coating on gelatin: Characterization, colon-targeted delivery, and anticancer activity.

Quercetin possesses multiple biological activities. To achieve efficient colon-specific release of quercetin, new composite nanofibers were developed by coating pH-responsive shellac on hydrophilic gelatin through coaxial electrospinning. These composite nanofibers contained bead-like structures. The encapsulation efficiency (87.6-98.5 %) and loading capacity (1.4-4.1 %) varied with increasing the initial quercetin addition amount (2.5-7.5 %). FTIR, XRD, and TGA results showed that the quercetin was successfully encapsulated in composite nanofibers in an amorphous state, with interactions occurring among quercetin, gelatin, and shellac. Composite nanofibers had pH-responsive surface wettability due to the shellac coating. In vitro digestion experiments showed that these composite nanofibers were highly stable in the upper gastrointestinal tract, with quercetin release ranging from 4.75 % to 12.54 %. In vivo organ distribution and pharmacokinetic studies demonstrated that quercetin could be sustainably released in the colon after oral administration of composite nanofibers. Besides, the enhanced anticancer activity of composite nanofibers was confirmed against HCT-116 cells by analyzing their effect on cell viability, cell cycle, and apoptosis. Overall, these novel composite nanofibers could deliver efficiently quercetin to the colon and achieve its sustained release, thus potential to regulate colon health. This system is also helpful in delivering other bioactives to the colon and exerting their functional effects.

Fabrication and characterization of shellac nanofibers with colon-targeted delivery of quercetin and its anticancer activity.

In this study, the feasibility of shellac nanofibers as carrier system for colonic delivery of quercetin was evaluated. Firstly, the nanofibers without and with different amounts (2.5 %, 5.0 %, and 7.5 %) of quercetin were fabricated using pure shellac as a carrier by electrospinning. The morphology of nanofibers was bead-shape confirmed by SEM. FTIR, XRD, and DSC analysis showed that quercetin was encapsulated into shellac nanofibers, forming an amorphous complex. The molecular docking simulation indicated quercetin bound well to shellac through hydrogen bonding and van der Waals forces. These nanofibers had higher thermal stability than pure quercetin, and their surface wettability exhibited a pH-responsive behavior. The loading capacity of quercetin varied from 2.25 % to 6.84 % with the increased amount of quercetin, and it affected the stability of nanofibers in food simulants by measuring the release profiles of quercetin. The shellac nanofibers had high gastrointestinal stability, with a minimum quercetin release of 16.87 % in simulated digestive fluids, while the remaining quercetin was delivered to the colon and was released gradually. Moreover, the nanofibers exerted enhanced anticancer activity against HCT-116 cells by arresting cell cycle in G0/G1 phase and inducing cell apoptosis. Overall, shellac nanofibers are promising materials for colon-targeted delivery of active compounds.

Fabrication of colon-targeted ethyl cellulose/gelatin hybrid nanofibers: Regulation of quercetin release and its anticancer activity.

A colon-targeted delivery system that can efficiently deliver and release quercetin is essential to improve its bioavailability. We previously found that hydrophobic ethyl cellulose (EC) nanofibers could efficiently deliver quercetin to colon, but the release of quercetin was limited. To address this problem, hydrophilic gelatin (GN) was used as a regulator, and quercetin-loaded nanofibers with different mass ratios of EC to GN (3:1, 1:1, 1:2, 1:3) were fabricated by electrospinning. All nanofibers had a cylindrical morphology and high encapsulation efficiency (over 94 %), and there existed molecular interactions among quercetin, EC, and GN. The high GN content reduced the thermal stability of nanofibers but increased their surface wettability. Besides, these nanofibers had good stability in acidic and aqueous foods. Importantly, the release of quercetin in the simulated gastrointestinal fluid was <3 %. The addition of GN was beneficial to the release of quercetin in colon, and nanofibers with EC to GN being 1:3 had a more preferable release performance. The anticancer activity of nanofibers against HCT-116 cells was proved by inhibiting cell viability through the induction of apoptosis. Therefore, these nanofibers are potential carriers for efficient colon-targeted delivery of bioactive compounds in the food industry.

Interaction mechanism of carotenoids and polyphenols in mango peels.

In this study, carotenoids and polyphenols were demonstrated to be the major active substances in the crude pigment extracts (CPE) of mango peels, accounting for 0.26 mg/g and 0.15 mg/g, respectively. The interactions between carotenoids and polyphenols in CPE was observed, as evidenced by that polyphenols significantly improved the antioxidant activity and storage stability of carotenoids in the CPE. Meanwhile, scanning electron microscopy showed that polyphenols are tightly bound to carotenoids. To further elucidate the interaction mechanism, the monomers of carotenoids and polyphenols were identified by HPLC and LC-MS analysis. Lutein (203.85 µg/g), ß-carotene (41.40 µg/g), zeaxanthin (4.20 µg/g) and α-carotene (1.50 µg/g) were authenticated as the primary monomers of carotenoids. Polyphenols were mainly consisted of gallic acid (95.10 µg/g), quercetin-3-ß-glucoside (29.10 µg/g), catechin (11.85 µg/g) and quercetin (11.55 µg/g). The interaction indexes between carotenoid and polyphenol monomer of CPE were calculated. The result indicated that lutein and gallic acid showed the greatest synergistic effect on the scavenging of DPPH and ABTS radical, suggesting the interaction between carotenoids and polyphenols in CPE was mainly caused by lutein and gallic acid. Molecular dynamics simulations and thermodynamic parameters analysis demonstrated that hydrogen bonding, electrostatic interactions, and van der Waals forces played dominant roles in the interaction between lutein and gallic acid, which was confirmed by Raman and X-ray diffraction. These results provided a new perspective on the interaction mechanism between carotenoids and polyphenols, which offered a novel strategy for the enhancement of the activities and stability of bioactive substances.

Encapsulation of quercetin into zein-ethyl cellulose coaxial nanofibers: Preparation, characterization and its anticancer activity.

In order to efficiently improve the colon-targeted delivery of quercetin, the hydrophobic core-shell nanofibers were fabricated to encapsulate quercetin using ethyl cellulose as the shell and zein as the core by coaxial electrospinning. The encapsulation efficiency of coaxial nanofibers reached >97 %. FTIR and XRD results revealed the interactions between quercetin and wall materials and quercetin was encapsulated in an amorphous state. The thermal stability and surface hydrophobicity of coaxial nanofibers were improved compared to the uniaxial zein fibers. After in vitro gastrointestinal digestion, the quercetin release from core-shell nanofibers was <12.38 %, while the corresponding value for zein fibers was 36.24 %. DPPH and FRAP assays showed that there was no significant difference in the antioxidant activity of quercetin before and after encapsulation. Furthermore, the encapsulated quercetin exhibited similar anti-proliferative activity against HCT-116 cells compared to the free form. The results suggest these coaxial nanofibers have potential applications in functional foods.

Differences of genomic alterations and heavy metals in non-small cell lung cancer with different histological subtypes.

PURPOSE: This study aimed to explore the correlations among heavy metals concentration, histologic subtypes and molecular characteristics in patients with non-small cell lung cancer (NSCLC). METHODS: In this study, an NGS panel of 82 tumor-associated genes was used to identify genomic alternations in 180 newly diagnosed patients with NSCLC. The concentrations of 18 heavy metals in the serum samples were detected by inductively coupled plasma emission spectrometry (ICP-MS). RESULTS: A total of 243 somatic mutations of 25 mutant genes were identified in 115 of 148 patients with LUAD and 45 somatic mutations of 15 mutant genes were found in 24 of 32 patients with LUSC. The genomic alternations, somatic interactions, traditional serum biomarkers, and heavy metals were markedly different between patients with LUAD and LUSC. Moreover, patients with LUSC were significantly positively correlated with Ba, but not LUAD. Lastly, patients with EGFR mutations presented significant negative correlations with Cd and Sr, whereas patients with TP53 mutations showed a significant positive correlation with Pb. CONCLUSION: The genomic alternations, somatic interactions, traditional serum biomarkers, and heavy metals were different between patients with LUAC and LUSC, and heavy metals (e.g., Ba, Pb, and Cd) may contribute to the tumorigenesis of NSCLC with different histological and molecular subtypes.

Primary sigmoid squamous cell carcinoma with liver metastasis: A case report.

BACKGROUND: The pathological type of simple squamous carcinoma in colorectal malignancies is rare. Simple squamous cell carcinoma of the colorectum occurs most frequently in the rectum. The clinicopathological features and biological behaviors of squamous colorectal carcinoma are unclear, and its prognosis may be worse than that of simple adenocarcinoma. Studies on squamous colorectal cancer are currently limited to case reports, and there is no standard treatment protocol. Therefore, more case reports are required to fully understand squamous colorectal cancer. CASE SUMMARY: We reported the case of a 56-year-old woman who complained of constipation for 2 years. Colonoscopy revealed a sigmoid colon tumor, and the pathological result of colonoscopy was squamous carcinoma. After completing the relevant assessment, the patient was clinically diagnosed with cT4aN0M0, stage IIB, and surgery was performed. Based on postoperative pathological results, the patient was diagnosed with pT4bN0M0, stage IIC. Six cycles of adjuvant chemotherapy were administered after surgery. Liver metastasis and abdominal wall mass were found more than 1 mo after the end of the last chemotherapy session. Targeted local treatment was not performed because the liver had multiple metastases, but I125 particle implantation of the abdominal wall mass was performed. Two cycles of first-line chemotherapy were administered after the surgery. The patient underwent 14 mo of treatment and eventually died from the tumor. CONCLUSION: Squamous carcinoma of sigmoid colon is a rare tumor with unclear pathogenesis. Its clinicopathological diagnosis should be paid close attention.

Development of Nervilia fordii Extract-Loaded Electrospun PVA/PVP Nanocomposite for Antioxidant Packaging.

An ethyl acetate extract from of Nervilia fordii (NFE) with considerable suppression activity on lipid peroxidation (LPO) was first obtained with total phenolic and flavonoid contents and anti-LPO activity (IC50) of 86.67 ± 2.5 mg GAE/g sample, 334.56 ± 4.7 mg RE/g extract and 0.307 mg/mL, respectively. In order to improve its stability and expand its application in antioxidant packaging, the nano-encapsulation of NFE within poly(vinyl alcohol) (PVA) and polyvinyl(pyrrolidone) (PVP) bio-composite film was then successfully developed using electrospinning. SEM analysis revealed that the NFE-loaded fibers exhibited similar morphology to the neat PVA/PVP fibers with a bead-free and smooth morphology. The encapsulation efficiency of NFE was higher than 90% and the encapsulated NFE still retained its antioxidant capacity. Fourier transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD) analysis confirmed the successful encapsulation of NFE into fibers and their compatibility, and the thermal stability of which was also improved due to the intermolecular interaction demonstrated by thermo gravimetric analysis (TGA). The ability to preserve the fish oil's oxidation and extend its shelf-life was also demonstrated, suggesting the obtained PVA/PVP/NFE fiber mat has the potential as a promising antioxidant food packaging material.

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.

Superior hypoglycemic activity of mulberry lacking monosaccharides is accompanied by better activation of the PI3K/Akt and AMPK signaling pathways.

Mulberry has been used as a functional food to treat type 2 diabetes mellitus (T2DM). However, it contains relatively high levels of fructose and glucose, which are not suitable for excess consumption by diabetic patients. In this study we used microbial fermentation to remove fructose and glucose from mulberry fruit, and then determined the effects on glycemia, the phosphatidylinositol 3-hydroxykinase/Akt (PI3K/Akt) and adenosine monophosphate-activated protein kinase (AMPK) signaling pathways and their downstream effectors in T2DM mice. After 5 weeks of administration, fermented mulberry (FM) significantly reduced fasting blood glucose, and also improved insulin sensitivity and glucose tolerance, more effectively than unfermented mulberry (MP). Moreover, compared with MP, FM had a more marked effect on the protein expression of intermediates in the PI3K/Akt and AMPK signaling pathways and their effectors: insulin receptor, phosphorylated Akt (Ser 308), phosphorylated glycogen synthase kinase-3ß (Ser 9), glycogen synthetase, phosphorylated forkhead transcription factor 1 (Ser 256), pyruvate carboxylase, phosphoenolpyruvate carboxykinase, fructose-1, 6-bisphosphatase, glucose-6-phosphatase, lipoprotein lipase, and phosphorylated AMPK (Thr 172), glucose transporter 4 and pyruvate kinase. These findings indicate that mulberry fruit modified to remove fructose and glucose may be more promising than whole mulberry as a treatment for diabetes.

Encapsulation of phycocyanin by prebiotics and polysaccharides-based electrospun fibers and improved colon cancer prevention effects.

To preserve bioactivity and achieve colon targeted release of phycocyanin (PC), the polysaccharides-based electrospun fiber mat (EFM) containing PC and prebiotics was prepared and characterized. In vitro release tests confirmed the colon targeting behavior of PC, in particular, faster release of PC was achieved due to the addition of prebiotics. Ritger-Peppas model confirmed that the release of PC in simulated colon fluids follows a mechanism of anomalous transport (non-Fickian). CCK-8 results showed that the combination of PC and prebiotics exerted a significant anti-proliferative effect on HCT116 cells with an IC50 values of 22.31, 17.12 and 11.63 mg/mL after 24, 48, and 72 h, respectively. Furthermore, the cell cycle and apoptosis analysis revealed that the inhibition activity on HCT116 cells was caused by arresting cell cycle at G0/G1 phase that is relevant to the inhibition of cyclin D1 and CDK4 and the up-regulation of p21 expression, and inducing cell apoptosis by mediating the mitochondrial pathway as well, in which the decrease of Bcl-2/Bax, activation of caspase 3 and release of cytochrome c were included. This study suggests that the PC-loaded EFM with GOS holds a great potential as an effective formulation for colon cancer prevention.

Targeted delivery of phycocyanin for the prevention of colon cancer using electrospun fibers.

Phycocyanin (PC), a water-soluble biliprotein, exhibits potent anti-colon cancer properties. However, its application in functional foods is limited by the poor stability and low bioavailability of PC. In this study, we successfully encapsulated PC by coaxial electrospinning. The colon targeted release of PC was achieved with retention of the antioxidant activity of PC. The PC-loaded electrospun fiber mat (EFM) obtained inhibited HCT116 cell growth in a dose-dependent and time-dependent manner. In particular, the PC-loaded EFM exerted its anti-cancer activity by blocking the cell cycle at the G0/G1 phase and inducing cell apoptosis involving the decrease of Bcl-2/Bax, activation of caspase 3 and release of cytochrome c. This study suggests that co-axial electrospinning is an efficient and effective way to deliver PC and improve its bioavailability; thus, it represents a promising approach for encapsulating functional ingredients for colon cancer prevention.

A colon-specific delivery system for quercetin with enhanced cancer prevention based on co-axial electrospinning.

The antioxidant quercetin (Q) is a bioactive compound that can inhibit colon cancer. However, its poor stability in the upper gastro-intestinal tract and low bioavailability compromised its benefits. In this study, a biopolymer-based colon-specific delivery system for Q was constructed by co-axial electrospinning. Quercetin-loaded chitosan nanoparticles (QCNP) were firstly prepared and characterized. Then, a Q-loaded electrospun fiber mat (Q-loaded EFM) containing prebiotics (galactooligosaccharide, GOS) was fabricated using sodium alginate as the shell layer and the abovementioned QCNP and prebiotics as the core layer. The DPPH assay showed that the antioxidant activity of Q was maintained in the obtained film. Owing to the addition of prebiotic GOS, the obtained fiber mat exhibited good prebiotic effects. In vitro release kinetics showed a sustained and targeted colon-specific release of Q from the Q-loaded EFM containing GOS, and the release rate of Q was enhanced by the presence of GOS. The obtained film also exhibited inhibition effects on Caco-2 cells in a dose- and time-dependent manner. Flow cytometry and fluorescence microscopy analysis indicated that the Q-loaded EFM containing GOS exerted its activity on colonic cancer cells by arresting the cell cycle in the G0/G1 phase and triggering apoptotic cell death. This study demonstrates the potential of the obtained film as an oral delivery system for encapsulation, protection, and release of Q at the colon for the oral therapy of colon disorders.

Preparation and Characterization of Electrospun Colon-Specific Delivery System for Quercetin and Its Antiproliferative Effect on Cancer Cells.

To improve the oral bioavailability of quercetin (Q) and achieve colon-specific release, a core-sheath electrospun fiber mat containing Q-loaded chitosan nanoparticle (Q-loaded EFM) was developed in this study. The nanoparticle was first fabricated, and its antioxidant activity was as effective as free Q. Then the uniform Q-loaded EFM was obtained using response surface methodology optimization, and its core-sheath structure was characterized by confocal laser scanning microscopy. In vitro release kinetics confirmed the colon targeting profile, and the release rate of Q varied inversely with fiber diameter. The data of Cell Counting Kit-8 suggested Q-loaded EFM inhibited the proliferation of Caco-2 cells in a dose- and time-dependent manner with an IC50 of 4.36, 2.81, and 2.01 mg/mL after 24, 48, and 72 h, respectively, and it was caused by arresting cell cycle on G0/G1 phase and triggering apoptotic cell death. This study suggests that the Q-loaded EFM represents a promising form in the oral therapy of colon disorders.