Caco-2 Cell Viability Research Articles

Sialylated human milk oligosaccharides prevent intestinal inflammation by inhibiting toll like receptor 4/NLRP3 inflammasome pathway in necrotizing enterocolitis rats

BackgroundNecrotizing enterocolitis (NEC) remains a fatal gastrointestinal disorder in neonates and has very limited therapeutic options. Sialylated human milk oligosaccharides (SHMOs) improve pathological changes in experimental NEC models. The objectives of this study were to investigate the involvement of NLRP3 inflammasome in NEC pathology and to explore the effects of SHMOs on toll-like receptor 4 (TLR4)/nuclear factor κB (NF-κB)/NLRP3 inflammatory pathway in experimental NEC.MethodsThe intestinal-tissue segments were collected from NEC infants, NLRP3 and caspase-1 positive cell were examined by immunohistochemistry. Newborn rats were hand-fed with formula containing or non-containing SHMOs (1500 mg/L) and exposed to hypoxia/cold stress to induce experimental NEC. The NEC pathological scores were evaluated; ileum protein expression of membrane TLR4 (mTLR4), inhibitor κB-α (IκB-α), NF-κB p65 subunit and phospho-NF-κB p65, as well as NLRP3 and caspase-1 were analyzed; ileum concentrations of interleukin-1β, interleukin-6, tumor necrosis factor-α (TNF-α) were also measured. Human colon epithelial Caco-2 cells were pre-treated with or without SHMOs and stimulated with TLR4 activator, lipopolysaccharide. Cell viabilities, mitochondrial membrane potential and supernatant matrix metalloprotease 2 (MMP-2) activities were analyzed.ResultsIncreased frequencies of NLRP3 and caspase-1 positive cells were found in the lamina propria of damaged intestinal area of NEC neonates. SHMOs supplementation reduced NEC incidence and pathological damage scores of rats challenged with hypoxia/cold stress. Accumulation of interleukin-1β, interleukin-6 and TNF-α in NEC group were attenuated in SHMOs + NEC group. Protein expression of mTLR4, NLRP3 and caspase-1 were elevated, cytoplasmic IκB-α were reduced, nuclear phospho-NF-κB p65 were increased in the ileum of NEC rats. SHMOs supplementation ameliorated the elevation of mTLR4, NLRP3 and caspase-1, restored IκB-α in the cytoplasmic fraction and reduced phospho-NF-κB p65 in the nuclear fraction in the ileum of NEC rats. SHMOs pre-treatment improved Caco-2 cell viability, mitigated loss of mitochondrial membrane potential and modulated MMP-2 activities in the presence of lipopolysaccharide in-vitro.ConclusionsThis study provided clinical evidence of involvement of NLRP3 inflammasome in NEC pathology, and demonstrated the protective actions of SHMOs might be owing to the suppression of TLR4/NF-κB/NLRP3-mediated inflammation in NEC.

Glutaraldehyde-crosslinked chitosan-polyethylene oxide nanofibers as a potential gastroretentive delivery system of nizatidine for augmented gastroprotective activity

Nizatidine (NIZ), a histamine H2-receptor antagonist, is soluble and stable in the stomach, however, it exhibits a short half-life and a rapid clearance. Therefore, chitosan (CS) and polyethylene oxide (PEO) nanofibers (NFs) at different weight ratios were prepared by electrospinning and characterized. The selected uncrosslinked and glutaraldehyde-crosslinked NFs were investigated regarding floating, solid-state characteristics, in vitro release, and in vitro cytotoxicity. The cytoprotective activity against ethanol-induced gastric injury in rats was evaluated through macroscopical, histopathological, immunohistochemical, and oxidative stress examinations. NFs based on 8:2 CS:PEO exhibited the smallest diameter (119.17 ± 22.05 nm) and the greatest mucoadhesion (22.82 ± 3.21 g/cm2), so they were crosslinked with glutaraldehyde. Solid-state characterization indicated polymers interaction, a successful crosslinking, and NIZ dispersion in NFs. Crosslinking maintained swollen mats at pH 1.2 (swelling% = 29.47 ± 3.50% at 24 h), retarded their erosion at pH 6.8 (swelling%= 84.64 ± 4.91% vs. 25.40 ± 0.79% for the uncrosslinked NFs at 24 h), augmented the floating up to 24 h vs. 10 min for the uncrosslinked NFs at pH 1.2 and prolonged the drug release (%drug released ≥ 93% at 24 h vs. 4 and 5 h for the uncrosslinked NFs at pHs 1.2 and 6.8, respectively). The viability of Caco-2 cells ≥ 86.87 ± 6.86% revealed NFs biocompatibility and unreacted glutaraldehyde removal. Crosslinking of 8:2 CS:PEO NFs potentiated the antiulcer activity (38.98 vs. 8.67 for the uncrosslinked NFs) as well as it preserved the gastric wall architecture, COX-2 expression, and oxidative stress markers levels of the normal rats.

Study on Effect of Vitexicarpin on the Biological Behavior of Colorectal Cancer Cells by Circ_0000419/MicroRNA-224

To investigate the effect and molecular mechanism of vitexicarpin on the biological behavior of colorectal cancer cells is the objective of the study. The human epithelial cell line Caco-2 cells were divided into control group, low, middle and high dose groups of vitexicarpin, plasmid cloning DNA-circ_0000419 group, plasmid cloning DNA group, anti-microRNA-224 group, anti-microRNA-224-negative control group, vitexicarpin+small interfering-circ_0000419 group and vitexicarpin+microRNA-224 group. Cell activity was detected by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide assay. Colony formation number was detected by plate clone formation experiment. Apoptosis was detected by flow cytometry. Scratch test was used to detect the migration distance of cells. Transwell method was used to detect the number of invasive cells; protein expression was detected by western blot; the expression levels of circ_0000419 and microRNA-224 were detected by real-time fluorescence quantitative polymerase chain reaction; dual-luciferase reporter assay was used to detect the targeting relationship between circ_0000419 and microRNA-224. After treatment with low, middle and high doses of vitexicarpin, the viability of Caco- 2 cells decreased, the number of colony formation decreased, the apoptosis rate increased, the migration distance decreased, the number of invasive cells decreased, the expression level of E-cadherin increased, the expression level of N-cadherin decreased, the expression level of circ_0000419 increased and the expression level of microRNA-224 decreased (p<0.05). Overexpression of circ_0000419 or inhibition of miR-224 expression decreased Caco-2 cell viability, decreased colony formation, increased apoptosis rate, decreased cell migration distance, decreased invasive cell number, increased expression of E-cadherin and decreased expression of N-cadherin (p<0.05). Interference with circ_0000419 or overexpression of microRNA-224 reverses the effects of vitexicarpin on proliferation, apoptosis, migration and invasion of Caco-2 cells; circ_0000419 targets the regulation of microRNA-224 expression. Vitexicarpin can inhibit the malignant biological behavior of colorectal cancer cells by circ_0000419/microRNA-224.

Dexmedetomidine Resists Intestinal Ischemia-Reperfusion Injury by Inhibiting TLR4/MyD88/NF-κB Signaling

BackgroundIntestinal ischemia/reperfusion (I/R) is a common clinical problem that occurs during various clinical pathological processes. Dexmedetomidine (DEX), a widely used anesthetic adjuvant agent, can induce protection against intestinal I/R in vivo; however, the underlying mechanism is not fully understood. In the present study, we aimed to investigate the protective effects of DEX and examine whether its mechanism was associated with the TLR4/MyD88/NF-κB signaling pathway. MethodsSprague–Dawley rats were pretreated with DEX and then subjected to I/R-induced intestinal injury. In vivo, intestinal histopathological examination and scoring were performed, the levels of serum intestinal fatty acid-binding protein (I-FABP), intestinal tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and expression levels of TLR4, MyD88, and NF-κB in the intestine were determined. In in vitro experiments, the human colon carcinoma cell line (Caco-2) was incubated with DEX before deprivation/reoxygenation (OGD/R) treatment. The cell viability of Caco-2 cells, the levels of lactate dehydrogenase (LDH), TNF-α, and IL-1β in the supernatant, as well as protein expression of TLR4, MyD88, and NF-κB in Caco-2 cells, were measured. Statistical analysis was performed using SPSS version 21.0. ResultsDEX preconditioning significantly reduced the intestinal pathological Chiu’s score, serum I-FABP, intestinal TNF-α, IL-1β levels, and the protein expression of TLR4, MyD88, and NF-κB in the rats with intestinal I/R injury. Similarly, in vitro, DEX pretreatment protected against OGD/R-induced Caco-2 cell damage and inhibited TLR4/MyD88/NF-κB signaling, as evidenced by increased cell viability, decreased LDH activity, reduced TNF-α and IL-1β levels, as well as downregulated TLR4, MyD88, and NF-κB protein levels. ConclusionsOur findings suggested that DEX could reduce intestinal I/R injury in rats and OGD/R damage in Caco-2 cells, and this protection might be attributed to antiinflammatory effects and inhibition of the TLR4/MyD88/NF-κB signaling pathway.

Toxicological assessment of a bioactive extract from Triplaris gardneriana Wedd. seeds using alternative models

The Triplaris gardneriana Wedd. seeds extract has great therapeutic potential due to numerous biological activities such as antioxidant, antibacterial and anti-inflammatory, which are associated with phenolic content. Although this herbal preparation has shown many benefits, recently their toxicity profile has begun to be explored. In this present study, the toxic effects of T. gardneriana seeds ethanolic extract (EETg) on biological systems of different taxonomical groups and levels of complexity (from cell culture to lower vertebrates) were assessed, through a variety of viability and toxicological assays. It was found that EETg did not impair the Saccharomyces cerevisiae growth at the highest tested concentration (200 µg/mL), and no toxicant evidence was observed in Aedes aegypti larvae or in Drosophila melanogaster adult stage. Contrarily, the extract reduced the viability of undifferentiated Caco-2 cells (250 µg/mL, 40% of viable cells), but did not affect differentiated ones. The embryotoxicity in Danio rerio model showed a LC50 of 7.41 mg/L (95% confidence interval, 4.78 − 11.49 mg/L). EETg did not show signs of toxicity in the majority of the models used, but lethality and malformations in zebrafish embryos occurred. Further analyses are needed to better understand the selective toxicity mechanism of EETg on zebrafish, as well as whether the toxic effects happen in higher vertebrates.

Evaluation of licorice (Glycyrrhiza glabra L.) as a novel microgreen from the anti-inflammatory potential of polyphenols

Literature on microgreens, an emerging new functional food crop, remains limited. Further study on microgreens as a promising dietary component for potential use in diet-based disease prevention is, therefore, essential. Given that the anti-inflammatory and anti-oxidant properties of mature licorice root material are well-documented, the objective of the present, preliminary study was to present licorice (<em>Glycyrrhiza glabra</em> L.) as a novel, edible fresh-food microgreen candidate. The effect of leaf, stem and root polyphenol extracts of 20-day old licorice microgreen seedlings on cell proliferation and viability of Caco-2 cells (simulating the intestinal epithelium), after pro-inflammatory induction of lipopolysaccharide (LPS), was examined and then compared to the polyphenol, flavonoid and anti-radical activities of the respective tissue extracts. Root extracts contained a two-fold less polyphenol (including flavonoid) content compared to leaf extracts, but with a five-fold lower anti-radical scavenging activity. Only the root extracts provided functional protection in terms of preserving cell proliferation and viability of LPS-treated Caco-2 cells. Some protection was also afforded by the stems, but the young leaf material offered no anti-inflammatory protection. Results point to a differing composition of anti-inflammatory polyphenols between the root and leaf, suggesting that the protective efficacy of the root extracts (and to some degree, the stem extracts) resides in inhibiting the pro-inflammatory cascade and resultant cytotoxic effects as opposed to a direct anti-radical scavenging activity. Potential use of licorice as a microgreen is promising, but will necessitate further study.

Green Synthesized Silver Nanoparticles-Mediated Cytotoxic Effect in Colorectal Cancer Cells: NF-κB Signal Induced Apoptosis Through Autophagy.

Green synthesized silver nanoparticles (Ag-NPs) have demonstrated promising effects, including cytotoxicity and anticancer potential, in different cell lines. Therefore, in our previous study, Ag-NPs were synthesized from the reduction of AgNO3 using Brassica rapa var. japonica (Bj) leaf extract as a reducing and stabilizing agent. The synthesized Ag-NPs were spherical in shape, with a size range of 15-30 nm. They had phase-centered cubic structure with strong growth inhibition potential against some bacteria. In continuation with our previous study, in the present study, we aimed to investigate the autophagy-regulated cytotoxic effect of Ag-NPs against human epithelial colorectal adenocarcinoma cells (Caco-2 cells). We found that the Bj leaf aqueous extract facilitated Brassica silver nanoparticles (Brassica Ag-NPs)-induced NF-κB mediated autophagy in Caco-2 cells. Results showed that Ag-NPs reduced cell viability of Caco-2 cells by inducing oxidative stress and DNA damage. Therefore, to understand the mechanism underlying the death-promoting activity of Ag-NPs in Caco-2 cells, western blotting was performed. Western blot analysis showed decreased expression of NFκB and increased expression of IκB, which is a sign of autophagy initiation. In addition, autophagosome formation was accelerated by the activity of p53 and light chain 3 (LC3) II. In addition, inhibition of Akt and mTOR also played a pivotal role in autophagy formation. Finally, excessive expansion of autophagy promoted apoptosis, which subsequently resulted in necrosis. These findings support a novel cell death-promoting function of autophagy by Ag-NPs in Caco-2 cells.

Evaluation of vitamin-producing and immunomodulatory lactic acid bacteria as a potential co-adjuvant for cancer therapy in a mouse model.

To evaluate a mixture of selected lactic acid bacteria (LAB) (a riboflavin-producer, a folate-producer and an immunomodulatory strain) as co-adjuvant for 5-fluorouracil (5-FU) chemotherapy in cell culture and using a 4T1 cell animal model of breast cancer. The viability of Caco-2 cells exposed to 5-FU and/or LAB was analysed. Mice bearing breast tumour were treated with 5-FU and/or LAB. Tumour growth was measured. Intestinal mucositis (IM) was evaluated in small intestine; haematological parameters and plasma cytokines were determined. The bacterial mixture did not negatively affect the cytotoxic activity of 5-FU on Caco-2 cells. The LAB mixture attenuated the IM and prevented blood cell decreases associated with 5-FU treatment. Mice that received 5-FU and LAB mixture decreased tumour growth and showed modulation of systemic cytokines modified by both tumour growth and 5-FU treatment. The LAB mixture by itself delayed tumour growth. The mixture of selected LAB was able to reduce the side-effects associated with chemotherapy without affecting its primary anti-tumour activity. This bacterial mixture could prevent the interruption of conventional oncologic therapies by reducing undesirable side-effects. In addition, this blend would provide essential nutrients (vitamins) to oncology patients.

Effects of intense pulsed light and gamma irradiation on Bacillus cereus spores in mesquite pod flour

This study was conducted to evaluate the inactivation of Bacillus cereus spore in mesquite flour with intense pulsed light (IPL) and gamma radiation. The physical, chemical, and toxicity of treated mesquite flour were also investigated. The results showed that up to 3.51 log10CFU/g B. cereus spore inactivation was achieved with 8 kGy of gamma radiation, and up to 1.69 log10CFU/g reductions could be achieved after 28s of catalytic IPL exposure. Although chemometric analysis showed 9-hydroxy-10,12-octadecadienoic acid was slightly increased after a 28s-catalytic IPL treatment, the concentration is within the acceptable range. No significant increase in acetic or propionic acids (typical off-flavor volatile compounds) was observed after either treatment. For cytotoxicity, the Caco-2 cell viability analysis revealed that these two technologies did not induce significant cytotoxicity to the treated mesquite flour. Overall, these two technologies exhibit strong potential for the decontamination of B. cereus in mesquite flour.

High voltage atmospheric cold plasma treatment inactivates Aspergillus flavus spores and deoxynivalenol toxin

Fungal contamination is a concern for the food industry. Fungal spores resist food sterilization treatments and produce mycotoxins that are toxic for animals and humans. Technologies that deactivate spores and toxins without impacting food quality are desirable. This study demonstrates the efficiency of a high voltage atmospheric cold plasma (HVACP) technology using air to generate reactive oxygen (ROS) and nitrogen (RNS) species for the degradation of Aspergillus flavus cultures and the deoxynivalenol (DON) mycotoxin. Optical emission and absorption spectroscopy demonstrate ionization of hydroxyl groups, atomic oxygen and nitrogen, and confirm production of ROS and RNS, e.g. O3, NO2, NO3, N2O4, and N2O5. Fungal cultures show a depletion in pigmentation and an ~50% spore inactivation after 1-min treatments. Treated spores show surface ablation and membrane degradation by scanning electron microscopy. Twenty-minute direct HVACP treatments of 100 μg of DON in one mL aqueous suspensions resulted in a greater than 99% reduction in DON structure and rescued over 80% of Caco-2 cell viability; however, the same treatment on 100 μg of powdered DON toxin only showed a 33% reduction in DON and only rescued 15% of cell viability. In summary, HVACP air treatment can inactivate both fungal spores and toxins in minutes.

Multitarget protection of Pterospartum tridentatum phenolic-rich extracts against a wide range of free radical species, antidiabetic activity and effects on human colon carcinoma (Caco-2) cells.

Pterospartum tridentatum is an edible endemic plant common in Portugal. Its flowers are used in culinary and are part of the popular medicine owing to its therapeutic properties. In this study, P. tridentatum flower infusion and hydroethanolic extracts were characterized concerning their phenolic composition and biological potential. By high-performance liquid chromatography method coupled to a diode array detector analysis were detected 13 phenolics. Genistein was the major one. Concerning the biological potential, the hydroethanolic extract was the most active against 2,2-diphenyl-1-picrylhydrazyl● and also as α-glucosidase inhibitor, while the infusion proved to be a remarkable free radical scavenger. Concerning human epithelial colorectal adenocarcinoma (Caco-2) cells, it was observed that both extracts displayed dose-dependent cytotoxicity on the viability of Caco-2 cells, presenting cytotoxic selectivity for these cancer cells when compared to the NHDF normal cell line. Additionally, they also showed protective effects against oxidative stress induced by tert-butyl hydroperoxide on Caco-2 cells. The obtained results suggest that these extracts may be interesting to enrich nutraceutical, pharmaceutical and food industries; however, more studies need to be done for their inclusion in pharmaceutical preparations and/or food additives. PRACTICAL APPLICATION: Pterospartum tridentatum is an endemic plant commonly used in folk medicine due to its depurative and hypoglycaemic properties. For this reason, we decided to determine the phenolic content of infusion and hydroethanolic extracts of P. tridentatum and their biological potential. The obtained results proved that P. tridentatum extracts are a rich source of bioactive compounds and possess great antioxidant and antidiabetic activities, ability to protect human erythrocytes against oxidative damage, inhibiting hemolysis, hemoglobin oxidation, and lipid peroxidation, and to interfere with Caco-2 cells growth and to protect these cells when subject to tert-butyl hydroperoxide oxidative stress conditions.

Cytotoxicity study of bakery product melanoidins on intestinal and endothelial cell lines

Melanoidins contribute to organoleptic properties of processed foods and exert benefits in health. The aim of this study was to isolate and characterize melanoidins from baked products (common bread, soft bread and biscuits), evaluate their cytotoxicity and determine their suitability as functional additives. Extraction yield, spectrophotometric characteristics, colorimetric properties, antioxidant capacity, and cytotoxicity of melanoidins were assessed. Among the studied products, soft bread had the highest extraction throughput. Melanoidins from biscuit showed the highest antioxidant capacity, closely followed by those of soft bread. Melanoidins did not exert cytotoxic effects on Caco-2 and HUVEC cells (viability was >80%). Nevertheless, incubation of HUVEC cells with melanoidins from common bread and biscuit slightly decreased viability, whereas gastrointestinal digestion of such melanoidins softened the decrease in cell viability. This study point to soft bread as a safe and efficient source of melanoidins, that could be potentially used in the future as functional ingredient.

A Novel Urease Inhibitor of Ruminal Microbiota Screened through Molecular Docking.

Inhibition of the urease activity of ruminal microbiota is not only beneficial for increasing dietary and endogenic urea-N utilization efficiency in ruminants but also might be applicable for the preservation of nitrogen fertilizer in soil and treatment of gastrointestinal and urinary tract infections caused by ureolytic bacteria. To discover urease inhibitors to efficiently target ruminal microbiota, the identified ruminal microbial metagenomic urease gene was used to construct a homology model to virtually screen urease inhibitors from the ChemDiv database by molecular docking. The GMQE and QMEAN values of the homology model were 0.85 and −0.37, respectively, indicating a good model quality. The inhibition effect of the screened urease inhibitor for ruminal urea degradation was assessed by ruminal microbial fermentation in vitro. The toxic effect of the candidate inhibitor was performed using gut Caco-2 cells in vitro. The results showed that compound 3-[1-[(aminocarbonyl)amino]-5-(4-methoxyphenyl)-1H-pyrrol-2-yl] propanoic acid (ChemDiv_ID: 6238-0047, IC50 = 65.86 μM) was found to be the most effective urease inhibitor among the candidate compounds. Compound 6238-0047 significantly lowered the amount of urea degradation and ammonia production in ruminal microbial fermentation. The 24 h degradation rate of compound 6238-0047 in ruminal microbial fermentation was 3.32%–16.00%. In addition, compound 6238-0047 (10–100 μM) had no significant adverse effect on the cell viability of Caco-2 cells. Molecular docking showed that compound 6238-0047 could interact with Asp359 in the active site and Cys318 in the flap region by the hydrogen bond and Pi-Alkyl interaction, respectively. Compound 6238-0047 could be used as a novel inhibitor for decreasing the urease activity of ruminal microbiota.

Thiolated PVP-Amphotericin B Complexes: An Innovative Approach toward Highly Mucoadhesive Gels for Mucosal Leishmaniasis Treatment.

The aim of this study was to synthesize polymeric excipients that can form mucoadhesive hydrogels containing amphotericin B (AmB) for the treatment of mucosal leishmaniasis. 2-(2-Acryloylaminoethyldisulfanyl)-nicotinic acid (ACENA) was copolymerized with N-vinyl pyrrolidone to obtain thiolated polyvinylpyrrolidone (PVP) that was then complexed with AmB to improve its solubility. The resulting structure of thiolated PVP was evaluated by 1H nuclear magnetic resonance to confirm S-protected thiol groups, and the average molecular mass was determined by size exclusion chromatography. Moreover, variants of thiolated PVP-AmB were studied for the thiol content, amount of complexed AmB, cytotoxicity, mucoadhesive properties, and antileishmaniasis activity. The highest achieved degree of thiolation was 772 ± 24.64 μmol/g, and the amount of complexed AmB was 27.05 ± 0.31 μmol per g of polymer. Thiolated PVP and thiolated PVP-AmB variants (0.5% m/v) showed no cytotoxicity, whereas the equivalent concentration of free AmB reduced Caco-2 cell viability to 70% within 24 h. Thiol-functionalized PVP and PVP-AmB complexes displayed 7.66- and 7.20-fold higher adhesion to the mucosal surface in comparison to unmodified PVP and PVP-AmB, respectively. In addition, variants of thiolated PVP-AmB complexes displayed 100% antileishmaniasis activity in comparison to the 80% killing efficiency of Fungizone, which has been applied in the equivalent AmB concentration of 0.2 μg/mL. Thiol-functionalized PVP proved to be a promising novel excipient for the delivery of AmB providing enhanced solubility and improved mucoadhesive properties which are beneficial for the treatment of mucosal leishmaniasis.

Production of mannooligosaccharides from various mannans and evaluation of their prebiotic potential

Aspergillus quadrilineatus endo-β-mannanase effectively degraded konjac glucomannan (66.09% w/v), copra meal (38.99% w/v) and locust bean galactomannan (20.94% w/v). High performance liquid chromatography (HPLC) analysis of KG hydrolysate indicated its mannooligosaccharides (MOS) content (656.38 mg/g) with high amounts of DP 5 oligosaccharide. Multi-scale characterization of mannan hydrolysate was done using FTIR and 13C NMR which revealed α and β form of galactose or glucose in MOS, respectively. CM and LBG hydrolysates (1 mg/mL) have shown cytotoxic effect and reduced cell viability of Caco-2 cells by 45% and 62%, respectively. MOS DP (1–4) derived from LBG supported better Lactobacilli biofilm formation as compared to KG hydrolysate containing high DP MOS (5–7). Lactobacilli effectively fermented MOS to generate acetate and propionate as main short chain fatty acids. Lactobacilli produced leucine, isoleucine and valine as branched chain amino acids when grown on LBG hydrolysate.

Influence of Surface Charge on the Functional Properties of Silica Nanoparticles and Cellular Toxicity

The effect of silica nanoparticles with a different surface charge on the cell viability of Caco-2 and RAW 264.7 cell lines was studied. Silica nanoparticles with narrow size distribution were prepared by Stobers method. These silica nanoparticles surface charge was varied from highly positive to highly negative, were single functionalized by APTES and multi functionalized by cysteine for amine and carboxyl groups. All other properties of the nanoparticles were kept constant. The unfunctionalized nanoparticles were used as control. Fourier Transform Infrared spectroscopy (FTIR) confirmed the presence of amine and carboxyl groups present on the surface of silica nanoparticles. The zeta potential measurements confirmed the successful modification of surface charge of silica nanoparticles in water. SEM images showed that the negatively charged, positively charged, and unfunctionalized nanoparticles with similar size and shape. MTT assay results indicated that the toxicity of SiO2 was cell type-dependent. CaCo-2 cells were highly resistant to nanoparticle treatment whereas RAW 264.7 (macrophages) predominantly charge dependent. The difference in toxicity could be attributed to the difference in the physiological function of each cell line. Among the three kinds of nanoparticles (negative, positive, and untreated), positively charged nanoparticles showed higher toxicity, which might be due to the attractive interaction between the negatively charged cell membrane and positively charged SiO2 nanoparticles.

Cytotoxicity Studies on Naproxen and Piroxicam Nanoformulations

Caco-2 cells were used as in vitro models to assess the cell viability characteristics of the carriers Soluplus®, Gelucire 50/13 and PVP K25 and the nanoformulations of Naproxen and Piroxicam. The assessment of cell viability was done using the tetrazolium salt based MTT assay. Gelucire 50/13 and its NFs were observed to have slightly higher cytotoxicity than PVP and Soluplus® and their respective NFs. All the NFs were observed to follow the cytotoxicity trend of the polymers. Our results show that no significant decrease in cell viability was seen until 0.01% concentration of Gelucire 50/13 for 12-h exposure. The NFs as well as the polymers alone had no significant effect on the viability of Caco-2 cells below 0.01% concentrations. The intestine has a protective mucous layer, whereas the cell culture monolayers do not. The intestinal tissues also have more capacity to recover from trauma than the cultured cells. Hence the present NFs can be expected to show lesser cytotoxicity when subjected to in vivo studies.&#x0D;

Properties of κ-carrageenan aerogels prepared by using different dissolution media and its application as drug delivery systems

This work reports the synthesis of kappa-carrageenan aerogels using different dissolution and crosslinking media in order to evaluate its effects on the textural properties of the matrixes and further on the drug loading and release performance. The different aerogel samples were produced through the dissolution of the biopolymer in water with addition of potassium salts as crosslinking agents and, in two different ionic liquids (ILs) derived from imidazolium ion, being further dried with supercritical CO2. The samples were characterized by Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR), Scanning Electron Microscopy (SEM), Nitrogen Adsorption-Desorption Analysis, Thermogravimetry (TGA) and Differential Scanning Calorimetry (DSC). The synthesized samples presented surface areas similar to the carrageenan aerogels being their structure constituted mainly by meso and macropores. The absence of ionic liquid in samples was demonstrated by DSC analysis and was corroborated by the cytotoxicity assays which revealed that cellular viability in Caco-2 cells was preserved. Tetracycline was used as a model drug and loaded in two of the prepared aerogels samples. The release experiments were performed with the composites to test in vitro drug release at physiologic pH. With a higher macroporosity, the kappa-carrageenan aerogel prepared by dissolution into ionic liquid showed a higher loading capacity than the one prepared by dissolution into water and a slightly higher release rate. The matrixes were considered to present a good potential to be used as biocompatible carriers on drug controlled delivery.

Valorization of Pichia spent medium via one-pot synthesis of biocompatible silver nanoparticles with potent antioxidant, antimicrobial, tyrosinase inhibitory and reusable catalytic activities.

The purpose of this study was to determine the feasibility of a novel biogenic synthesis of silver nanoparticles using Pichia pastoris spent medium - a major waste product from heterologous protein expression as the sole reducing and capping agent, with potential biological, antimicrobial and wastewater remediation applications. Using UV-vis spectroscopy, TEM, XRD, EDX, FTIR, SEM we demonstrated the successful bio-fabrication of Pichia spent medium encapsulated silver nanoparticles (PSM-AgNPs). PSM-AgNPs displayed substantial antiradical activity against DPPH and ABTS. The antiradical activity against ABTS was similar to that of the control, ascorbic acid. PSM-AgNPs also revealed potent anti-tyrosinase and antibacterial activity against some common foodborne pathogenic microbes. Human erythrocyte hemolytic and embryonic colon Caco-2 cell viability assays suggest that PSM-AgNPs was biocompatible. In addition, PSM-AgNPs, was also effective in the catalytic degradation of methyl orange and Congo red dyes with pseudo first order rate constants of 0.2301min-1 and 4.7×10-3s-1, respectively. These results present a clean, convenient, and inexpensive approach for the biosynthesis of silver nanoparticles with potential implications in the eco-friendly, safe and effective utilization of waste culture media, mitigation of pathogenic bacteria and management of industrial effluents.

Preparation and Characterization of Celecoxib Entrapped Guar Gum Nanoparticles Targeted for Oral Drug Delivery against Colon Cancer: An In-Vitro Study

The present study is an attempt to synthesize nanosized guar gum carriers encapsulating celecoxib as the chemopreventive agent for experimental colorectal cancer (CRC). Guar gum nanoparticles without celecoxib (eGGNPs) and celecoxib loaded guar gum nanoparticles (cGGNPs) were prepared by oil-in-water emulsification and in situ polymer crosslinking method. Electron microscopy, zeta potential and fourier transform infrared spectra analysis was used to affirm the size, stability and morphology of the nanoparticles. In-vitro drug release was investigated using dialysis method. Further, the effect of nanoparticles (eGGNPs &amp; cGGNPs) was evaluated on Caco 2 colon cancer cell lines. Spherical guar gum nanoparticles were obtained in the size range of 200±6nm with zeta potential of -32.1mV indicating good stability of the GGNPs with drug loading of 30±3.2%, and drug release following zero order kinetics. The eGGNPs had no effect on Caco2 cell viability whereas the cGGNPs showed time and concentration dependent growth inhibition of Caco 2 cells. These findings suggest the successful preparation of chemopreventive nanoparticles that can be targeted as the prophylactic agent for experimental colorectal cancer.&#x0D; Keywords: nanoparticles, guar gum, celecoxib, colorectal cancer, release kinetics, cytotoxicity