Effects of a Curcumin/Silymarin/Yeast-Based Mycotoxin Detoxifier on Redox Status and Growth Performance of Weaned Piglets under Field Conditions.

The aim of this in vivo study was to investigate the effects of a novel mycotoxin detoxifier whose formulation includes clay (bentonite and sepiolite), phytogenic feed additives (curcumin and silymarin) and postbiotics (yeast products) on the health, performance and redox status of weaned piglets under the dietary challenge of fumonisins (FUMs). The study was conducted in duplicate in the course of two independent trials on two different farms. One hundred and fifty (150) weaned piglets per trial farm were allocated into two separate groups: (a) T1 (control group): 75 weaned piglets received FUM-contaminated feed and (b) T2 (experimental group): 75 weaned piglets received FUM-contaminated feed with the mycotoxin-detoxifying agent from the day of weaning (28 days) until 70 days of age. Thiobarbituric acid reactive substances (TBARSs), protein carbonyls (CARBs) and the overall antioxidant capacity (TAC) were assessed in plasma as indicators of redox status at 45 and 70 days of age. Furthermore, mortality and performance parameters were recorded at 28, 45 and 70 days of age, while histopathological examination was performed at the end of the trial period (day 70). The results of the present study reveal the beneficial effects of supplementing a novel mycotoxin detoxifier in the diets of weaners, including improved redox status, potential hepatoprotective properties and enhanced growth performance.

Mineral Phase Reconfiguration Enables the High Enzyme-like Activity of Vermiculite for Antibacterial Application.

Phyllosilicates-based nanomaterials, particularly iron-rich vermiculite (VMT), have wide applications in biomedicine. However, the lack of effective methods to activate the functional layer covered by the external inert layer limits their future applications. Herein, we report a mineral phase reconfiguration strategy to prepare novel nanozymes by a molten salt method. The peroxidase-like activity of the VMT reconfiguration nanozyme is 10 times that of VMT, due to the electronic structure change of iron in VMT. Density-functional theory calculations confirmed that the upward shifted d-band center of the VMT reconfiguration nanozyme promoted the adsorption of H2O2 on the active iron sites and significantly elongated the O-O bond lengths. The reconfiguration nanozyme exhibited nearly 100% antibacterial activity toward Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), much higher than that of VMT (E. coli 10%, S. aureus 21%). This work provides new insights for the rational design of efficient bioactive phyllosilicates-based nanozyme.

Influences of potassium solubilizing bacteria and K-feldspar on enzyme activities and metabolic activities of the bacterial communities in kiwifruit planting soil.

A pot experiment was conducted with kiwifruit planting soil to evaluate the impacts of potassium solubilizing bacteria (KSB) and K-feldspar on the soil nutrient levels, enzyme activities, and microecological environment. The effects were investigated of three inoculation treatments (T1: K-feldspar, T2: KSB, and T3: KSB with K-feldspar) and a non-inoculation treatment (CK) on the enzyme activities and the metabolic activities of the bacterial communities in kiwifruit rhizosphere soil. The results showed that the total nitrogen, available phosphorus, available potassium, and organic matter contents in T3 were 18.19%, 45.22%, 15.06%, and 4.17% higher, respectively, than those in CK at the end of the experiment (90 days). Compared with CK, T3 significantly increased the invertase, urease, acid phosphatase, and polyphenol oxidase activities. T3 had a higher kiwifruit root activity, but there were no significant differences among the four treatments (P > 0.05). T3 significantly altered the bacterial community diversity, increased the utilization of phenolic compounds and polymers, and decreased the utilization of amino acids. Redundancy analysis indicated that soil nutrients (total nitrogen, available phosphorus, and available potassium) and enzyme activities (urease and acid phosphatase) had more important effects on the metabolic activities of the bacterial communities. Co-inoculation enhanced the soil nutrients, enzyme activities, and bacterial community diversity. KSB co-inoculated with K-feldspar has the potential to improve the soil fertility, microbial metabolic activity and plant growth.

Saccharomyces cerevisiae Cell Wall-Based Adsorbent Reduces Aflatoxin B1 Absorption in Rats.

Mycotoxins are naturally occurring toxins that can affect livestock health and performance upon consumption of contaminated feedstuffs. To mitigate the negative effects of mycotoxins, sequestering agents, adsorbents, or binders can be included to feed to interact with toxins, aiding their passage through the gastrointestinal tract (GI) and reducing their bioavailability. The parietal cell wall components of Saccharomyces cerevisiae have been found to interact in vitro with mycotoxins, such as, but not limited to, aflatoxin B1 (AFB1), and to improve animal performance when added to contaminated diets in vivo. The present study aimed to examine the pharmacokinetics of the absorption of radiolabeled AFB1 in rats in the presence of a yeast cell wall-based adsorbent (YCW) compared with that in the presence of the clay-based binder hydrated sodium calcium aluminosilicate (HSCAS). The results of the initial pharmacokinetic analysis showed that the absorption process across the GI tract was relatively slow, occurring over a matter of hours rather than minutes. The inclusion of mycotoxin binders increased the recovery of radiolabeled AFB1 in the small intestine, cecum, and colon at 5 and 10 h, revealing that they prevented AFB1 absorption compared with a control diet. Additionally, the accumulation of radiolabeled AFB1 was more significant in the blood plasma, kidney, and liver of animals fed the control diet, again showing the ability of the binders to reduce the assimilation of AFB1 into the body. The results showed the potential of YCW in reducing the absorption of AFB1 in vivo, and in protecting against the damaging effects of AFB1 contamination.

Modified hydrated sodium calcium aluminosilicate-supplemented diet protects porcine oocyte quality from zearalenone toxicity.

Zearalenone (ZEN) is one of the most common mycotoxins produced by fungus in contaminated feed. ZEN has multiple toxicities, including reproductive toxicity of domestic animals, particularly pigs. However, studies on the effects of ZEN on ovary/oocytes have been primarily based on in vitro experiments, and there is still no evidence from porcine in vivo models due to multiple limitations. Moreover, no report has investigated the effect of hydrated sodium calcium aluminosilicate (HSCAS) as a supplement on pig oocyte quality. In the present study, we fed pigs a 1.0 mg/kg ZEN-contaminated diet for 10 days. The results showed that pigs fed ZEN presented reduced oocyte-cumulus cell interactions, an increase in the number of denuded oocytes in ovaries, a decrease in the number of oocytes in each ovary, and an increase in the oocyte death rate. Oocytes from ZEN-exposed pigs exhibited a delayed cell cycle and abnormal cytoskeletal dynamics during meiotic maturation, which could be due to oxidative stress-induced autophagy. Moreover, we also show that supplementing the ZEN-contaminated diet with modified HSCAS effectively protected porcine oocyte quality. Taken together, our study provides in vivo data demonstrating the protective effects of HSCAS against ZEN toxicity in porcine oocytes.

Antibacterial activity of Zn-loaded Cuban zeolite against Helicobacter pylori in comparison to its Na-loaded and unmodified counterparts.

Helicobacter pylori can be found in the stomach of about half of the humans, and a large population can be associated with serious diseases. To survive in the stomach H. pylori increases the pH locally by producing ammonia which binds to H+ becoming ammonium. This work investigated the effects on the in-vitro growth of H. pylori of a natural cation-exchanger mainly composed (≈70%) of clinoptilolite and mordenite. The zeolitized material from Cuba was evaluated in its original form (M), as well as in its Na- (M-Na) and Zn-exchanged (M-Zn) counterparts. In the preliminary agar cup diffusion test, H. pylori revealed susceptibility only to M-Zn, with a direct relationship between concentration and width of inhibition halo. Further experiments evidenced that bacterium replication increases when ammonium is supplied to the growth medium and decreases when zeolites subtract NH4+ via ion exchange. Due to the multi-cationic population of its zeolites M was not effective enough in removing ammonium and, in the Minimum Inhibitory Concentration (MIC) test, allowed bacterial growth even at a concentration of 50 mg/mL. Inhibition was achieved with M-Na because it contained sodium zeolites capable of maximizing NH4+ subtraction, although the MIC was high (30 mg/mL). M-Zn evidenced a more effective inhibitory capacity, with a MIC of 4 mg/mL. Zinc has antimicrobial properties and H. pylori growth was affected by Zn2+ released from clinoptilolite and mordenite. These zeolites, being more selective towards NH4+ than Zn2+, can also subtract ammonium to the bacterium, thus enhancing the efficacy of M-Zn.

Impact of aluminosilicates on productivity, carcass traits, meat quality, and jejunum morphology of broiler chickens.

The aim of the study was to compare production results and quality of meat, as well as histological features of the jejunum in broiler chickens administered feed with 1% addition of zeolite or halloysite, with the addition of aluminosilicates to litter (4.50 kg/m2) throughout the rearing. In the experiment, 300 male broilers were used for 6 wk. They were divided into 3 groups, each of 10 repetitions (10 birds each). Group 1 was a control, halloysite was added to feed and litter in group 2, while zeolite was applied instead of halloysite in group 3. After rearing, 10 selected birds from each group were slaughtered. Selected production properties and degree of footpad dermatitis were examined, and histomorphometric examination of the jejunum was performed. The lowest yield and the highest proportion of neck with skin in the carcass were demonstrated in group 2 (P < 0.05). The lowest percentage of skin with subcutaneous fat was found in group 3 (P < 0.05). A decrease in lightness (L∗) and yellowness (b∗) was demonstrated in group 2, while redness (a∗) was the lowest in group 3 (P < 0.05). Group 2 was characterized by the lowest water-holding capacity in breast muscles, and in group 3, in leg muscles (P < 0.05). In group 3, the highest fat content and the lowest water content in the breast muscles (P < 0.05) were found. The leg muscles in groups 2 and 3 were characterized by the highest a∗, and in group 2, by b∗. The control group had the lowest protein and the highest fat content in leg muscles. In the intestine from group 2, a higher height (P < 0.05) and surface area (P < 0.01) of intestinal villi were found, in comparison to group 3. The width of intestinal villi was higher in groups 2 and 1 than in group 3 (P < 0.05), similarly the depth of intestinal crypts. The addition of zeolite could be proposed because of the obtained production results, while the halloysite had a positive effect on the histomorphometric features of the jejunum.

Dendritic Mesoporous Silica Nanoparticle Adjuvants Modified with Binuclear Aluminum Complex: Coordination Chemistry Dictates Adjuvanticity.

Aluminum-containing adjuvants used in vaccine formulations suffer from low cellular immunity, severe aggregation, and accumulation in the brain. Conventional aluminosilicates widely used in the chemical industry focus mainly on acidic sites for catalytic applications, but they are rarely used as adjuvants. Reported here is an innovative "ligand-assisted steric hindrance" strategy to create a high density of six-coordinate VI Al-OH groups with basicity on dendritic mesoporous silica nanoparticles as new nanoadjuvants. Compared to four-coordinate IV Al-modified counterparts, VI Al-OH-rich aluminosilicate nanoadjuvants enhance cellular delivery of antigens and provoke stronger cellular immunity. Moreover, the aluminum accumulation in the brain is more reduced than that with a commercial adjuvant. These results show that coordination chemistry can be used to control the adjuvanticity, providing new understanding in the development of next-generation vaccine adjuvants.

Efficacy of some feed additives to attenuate the hepato-renal damage induced by aflatoxin B1 in rabbits.

The present trial was conducted to evaluate the beneficial role of some feed additives (potassium sorbate; Sor, hydrated sodium calcium almuniosilicate; Hsc and l-methionine; L-M) in attenuating the hepatic and renal toxicity of aflatoxin B1 (AFB1) in rabbits. A total number of 72 NZW growing rabbits (5 week-old) were divided into six experimental groups (four replicates with three rabbits each) as follows: control group, AFB1 group (supplemented with AFB1 0.3 mg/kg diet), AFB1 + Sor group (AFB1 0.3 mg/kg diet + Sor 2 g/kg diet), AFB1 + Hsc group (AFB1 0.3 mg/kg diet + Hsc 5 g/kg diet), AFB1 + L-M group (AFB1 0.3 mg/kg diet + L-M 8 g/kg diet) and AFB1 + Mix group (AFB1 0.3 mg/kg diet + 2 Sor + 5 Hsc + 8 L-M g/kg diet). Serum levels of total protein, albumin and globulin were significantly reduced by AF. AF increased the serum activity of aspartate aminotransferase (AST), alanine amino transferase (ALT) and alkaline phosphatase (ALP) enzymes. While, they were reduced in AF + Sor and AF + Mix groups compared with AF group. AF increased the level of cystatin C and Beta-2 microglobulin (BMG). All other supplements significantly reduced the level of cystatin C than AF; however, this reduction was more pronounced in AF-L-M group. AF + Sor, AF + L-M and AF + Mix equally reduced the BMG level than AF and AF + HSc, however, still higher than control. AF elevated the total cholesterol (TC) and LDL-cholesterol levels. A significant reduction in HDL cholesterol was seen in AF group. Additionally, AF induced pathological alterations in the liver and kidney of exposed rabbits on the other hands, the three additives separately or in mix attenuated the Af-induced alterations. In conclusion, the dietary supplementation of Sor, L-M, Hsc or their mixture was effective in ameliorating the negative effects of AFB1 on liver and kidney function and structure in rabbits with more better improvement obtained by Sor or L-M separately.

Injectable MMP-Responsive Nanotube-Modified Gelatin Hydrogel for Dental Infection Ablation.

A photocrosslinkable gelatin methacryloyl (GelMA) hydrogel has been widely examined in regenerative engineering because of its good cell-tissue affinity and degradability in the presence of matrix metalloproteinases. A halloysite aluminosilicate nanotube (HNT) is a known reservoir for the loading and sustained delivery of therapeutics. Here, we formulate injectable chlorhexidine (CHX)-loaded nanotube-modified GelMA hydrogel that is cytocompatible and biodegradable and provides sustained release of CHX for infection ablation while displaying good biocompatibility. The effects of HNTs and CHX on hydrogel degradability and mechanical properties, as well as on the kinetics of CHX release, and on the antimicrobial efficacy against oral pathogens were systematically assessed. Cytocompatibility in stem cells from human exfoliated deciduous teeth and inflammatory response in vivo using a subcutaneous rat model were determined. Our hydrogel system, that is, (CHX)-loaded nanotube-modified GelMA showed minimum localized inflammatory responses, supporting its ability for drug delivery applications. Moreover, we showed that the incorporation of CHX-loaded nanotubes reduces the mechanical properties, increases the swelling ratio, and diminishes the degradation rate of the hydrogels. Importantly, the presence of CHX-loaded nanotubes inhibits bacterial growth with minimal cell toxicity. Our findings provide a new strategy to modify GelMA hydrogel with chlorhexidine-loaded nanotubes for clinical use as an injectable drug delivery strategy for dental infection ablation.

Aluminosilicate Nanocomposites from Incinerated Chinese Holy Joss Fly Ash: A Potential Nanocarrier for Drug Cargos.

An incredible amount of joss fly ash is produced from the burning of Chinese holy joss paper; thus, an excellent method of recycling joss fly ash waste to extract aluminosilicate nanocomposites is explored. The present research aims to introduce a novel method to recycle joss fly ash through a simple and straightforward experimental procedure involving acidic and alkaline treatments. The synthesized aluminosilicate nanocomposite was characterized to justify its structural and physiochemical characteristics. A morphological analysis was performed with field-emission transmission electron microscopy, and scanning electron microscopy revealed the size of the aluminosilicate nanocomposite to be ~25 nm, while also confirming a uniformly spherical-shaped nanostructure. The elemental composition was measured by energy dispersive spectroscopy and revealed the Si to Al ratio to be 13.24 to 7.96, showing the high purity of the extracted nanocomposite. The roughness and particle distribution were analyzed using atomic force microscopy and a zeta analysis. X-ray diffraction patterns showed a synthesis of faceted and cubic aluminosilicate crystals in the nanocomposites. The presence of silica and aluminum was further proven by X-ray photoelectron spectroscopy, and the functional groups were recognized through Fourier transform infrared spectroscopy. The thermal capacity of the nanocomposite was examined by a thermogravimetric analysis. In addition, the research suggested the promising application of aluminosilicate nanocomposites as drug carriers. The above was justified by an enzyme-linked apta-sorbent assay, which claimed that the limit of the aptasensing aluminosilicate-conjugated ampicillin was two-fold higher than that in the absence of the nanocomposite. The drug delivery property was further justified through an antibacterial analysis against Escherichia coli (gram-negative) and Bacillus subtilis (gram-positive).

Dietary supplementation of potassium sorbate, hydrated sodium calcium almuniosilicate and methionine enhances growth, antioxidant status and immunity in growing rabbits exposed to aflatoxin B1 in the diet.

The present experiment was conducted to evaluate the effect of dietary supplementation with some feed additives (potassium sorbate; Sor, hydrated sodium calcium almuniosilicate; Hsc and L-methionine; L-M) against aflatoxin B1 (AF) toxicity in rabbits. A total of 72 growing rabbits (5-week-old) were distributed into six equal groups (4 replicates with 3 rabbits each). The experimental groups are as follows: control group, AF group (supplemented with AF 0.3 mg/kg diet), AF + Sor group (AF 0.3 mg/kg diet + Sor 2 g/kg diet), AF + Hsc group (AF 0.3 mg/kg diet + Hsc 5 g/kg diet), AF + L-M group (AF 0.3 mg/kg diet + L-M 8 g/kg diet) and AF + Mix group (AF 0.3 mg/kg diet + 2 Sor + 5 Hsc + 8 L-M g/kg diet). Live body weight and weight gain at 13 weeks of age were significantly reduced by AF. Feed intake at 13 weeks of age was decreased in AF, AF + Hsc and AF + Mix compared to the control. AF, AF + Hsc and AF + Mix showed the lowest total antioxidant capacity compared to the control. The highest level of reactive oxygen species and 8-Hydroxy-2-desoxyguanosine was observed in AF group. Using of other supplements with AF increased immunoglobulinM than AF alone. In conclusion, dietary supplementation of Sor, L-M, Hsc or their mixture was effective in reducing the adverse effects of AF on performance, antioxidant and immune status of rabbits with more better improvement obtained by Sor or L-M separately.

Polyethylene/Organo-Inorgano Vermiculites and Their Antimicrobial Properties.

Clay mineral vermiculite was treated with silver and copper nitrate solutions and samples were subsequently modified with organic compound (dodecylamine) via solid-solid melt intercalation. Prepared organo-inorgano vermiculites were used as nanofillers to the polyethylene matrix. Mixtures of polyethylene with vermiculite nanofillers, prepared by melt compounding technique, were pressed into thin plates. Structure changes of prepared powder vermiculite nanofillers and polyethylene/vermiculite composites were studied by X-ray diffraction analysis. The X-ray diffraction patterns of vermiculite nanofillers confirm intercalation of dodecylamine into the vermiculite interlayer. Antimicrobial properties of powder vermiculite nanofillers were evaluated by the minimum inhibitory concentration of samples which is needed to completely stop the bacterial growth and polyethylene/vermiculite composites were evaluated by the number of colony forming units survived on surfaces of composite plates. Different bacterial strains were studied: (1) Gram-positive, represented by bacteria Staphylococcus aureus and Enterococcus faecalis, (2) Gram-negative, represented by bacteria Escherichia coli and Pseudomonas aeruginosa, and (3) yeast, Candida albicans. Powder vermiculite nanofillers and surfaces of polyethylene/vermiculite composites showed good antimicrobial effect against tested bacteria and yeast. Powder vermiculite nanofillers show antimicrobial effect already after 30 minutes of tested time. Composite plates exhibited decrease of colony forming units number about 5-7 logarithmic orders depending on bacteria after 24 hours of tested time.

Doped ZnO nanoparticles impregnated on Kaolinite (Clay): A reusable nanocomposite for photocatalytic disinfection of multidrug resistant Enterobacter sp. under visible light.

Water contamination by multidrug resistant (MDR) enteric bacteria can be considered as the foremost cause of gastrointestinal infections and poses a threat to global public health. Therefore, there is an urgent need to pursue unorthodox techniques with potential of community scale applications for purging of water borne pathogenic bacteria. We communicate visible-light assisted photocatalytic disinfection (PCD) of an enteric MDR bacterium; Enterobacter sp. using Fe-doped ZnO nanoparticles impregnated on Kaolinite (Clay) (ZnO/K). ZnO/K was synthesized by co-precipitation technique and was found to be more effective than Fe-doped ZnO (ZnO) and Kaolinite for PCD process. Analysis from fluorescence microscopy and electron microscopy (FESEM) proposed complete bacterial cell death via PCD due to damage of bacterial cell membrane. Experimental evidences indicated that O2- could be acting as the most significant component in disinfection of MDR Enterobacter sp. in visible-light assisted PCD process in presence of ZnO/K. Considering the experimental data of Resazurin assay, it is proposed that reactive oxygen species (ROS) generated during PCD might have impeded the oxido-reductase enzyme system of the bacteria and hence trammeling its metabolic activity. Crystal structure and particle size of ZnO/K was found to be unaltered during the photocatalytic process indicating its potential for reusability. When ZnO/K was exposed to HCT-116 Human Colorectal Carcinoma cell lines, about 79% cell survivability was noticed. The synthesized material was successful in completely disinfecting the target microorganism in Zebra Fish model, without producing any adverse effects on the Fish itself, further reinforcing its biocompatibility factor. High effectiveness of PCD process using ZnO/K under visible light in disinfecting enteric MDR bacteria, might have promising outcome as an alternative water disinfection technology to prevent the spread of infectious and resistant bacteria without producing any adverse effect on non-specific flora and fauna.

Antimicrobial gelatin-based elastomer nanocomposite membrane loaded with ciprofloxacin and polymyxin B sulfate in halloysite nanotubes for wound dressing.

Bacterial infection is a major problem world-wide, especially in wound treatment where it can severely prolong the healing process. In this study, a double drug co-delivery elastic antibacterial nanocomposite was developed by combining ciprofloxacin (CPX) and polymyxin B sulfate-loaded halloysite clay nanotubes (HNTs-B) into a gelatin elastomer. CPX nanoparticles which act against both gram positive and gram-negative bacterium were dispersed directly in the matrix, and polymyxin B sulfate was loaded in HNTs and then distributed into the matrix. The effect of CPX and HNTs-B content on the physical properties, cytotoxicity, fibroblast adhesion and proliferation, in vitro drug release behavior and anti-bacterial properties were systematically investigated. The ciprofloxacin crystals and HNT-B were distributed in the matrix uniformly. The HNTs in the drug loading system not only enhanced the matrix' tensile strength but also slowed down the release rate of the high dissoluble polymyxin B sulfate. When the amount of HNT in the matrix increased, the thermal stability and tensile strength also increased but the polymyxin B sulfate release rate decreased because the HNTs prevented the drug release inside. All the nanocomposites exhibited antimicrobial activity against both gram-negative and gram-positive bacteria with the dual combination of drugs released from the nanocomposites. Furthermore, this kind of gelatin-based nanocomposites possesses higher water-absorbing quality, low cytotoxicity, adaptable biodegradability and good elasticity which can satisfy the requirements for an ideal biomaterial for use in wound healing applications.

pH and near-infrared active; chitosan-coated halloysite nanotubes loaded with curcumin-Au hybrid nanoparticles for cancer drug delivery.

In this work, we propose biofriendly in-situ preparation method of Au NPs (hexagonal and rod-shape structures) in the lumen as well as the surface cage of biocompatible halloysite nanotubes (HNTs) using curcumin (CUR) as anticancer drug and subsequently coating with bio-adhesive chitosan (CS) as a polysaccharide. The formation of Au NPs and their interactions with CUR and CS exist in the HNTs has been characterized by FTIR, XRD, XPS, STEM techniques. Interestingly, Au NPs showed longitudinal plasmon resonance bands at 760 and 980 nm that indicate the near-infrared (NIR) responsive property of hybrid nanoparticles. Rod shape and hexagonal structures of Au NPs were produced as confirmed by TEM images. The loading efficiency of CUR was found as much as 12%. Importantly, more CUR release was achieved under acidic conditions (pH 5.5) than basic conditions (pH 7.4). The anticancer potential of HNT hybrid nanoparticles on MCF-7 cancer cells was studied and showed efficient anticancer activity under intracellular tumor cell environment (pH 5.5) than extracellular conditions (pH 7.4). Moreover, the developed HNT hybrid nanoparticles consisting of Au NPs (NIR responsive property) and pH-responsive CUR release could make it suitable for cancer cell-targeted drug delivery platform with NIR-imaging.

Quorum Sensing Disruption in Vibrio harveyi Bacteria by Clay Materials.

This work describes the use of clay minerals as catalysts for the degradation of quorum sensing molecule N-(3-oxooctanoyl)-dl-homoserine lactone. Certain clay minerals as a result of their surface properties and porosity can catalytically degrade the quorum sensing molecule into smaller fragments. The disruption of quorum sensing by clay in a growing Gram-negative Vibrio harveyi bacteria culture was also studied by monitoring luminescence and population density of the bacteria, wherein quenching of bacterial quorum sensing activity was observed by means of luminescence reduction. The results of this study show that food-grade clays can be used as biocatalysts in disrupting bacterial activity in various media.

Facile fabrication and characterization of a novel oral pH-sensitive drug delivery system based on CMC hydrogel and HNT-AT nanohybrid.

The main aim of the present study was to design pH-sensitive bionanocomposite hydrogel beads based on CMC and HNT-AT nanohybrid and evaluate whether prepared bionanocomposite beads have the potential to be used in drug delivery applications. Atenolol (AT), as a model drug, was incorporated into the lumen of HA nanotubes via the co-precipitation technique. HNT/AT nanohybrid and CMC/HNT-AT beads were characterized via XRD, SEM, TGA, and FT-IR techniques. Drug loading and encapsulation efficiency was found to be high for CMC/HNT3 beads. Moreover, the swelling and drug release properties of the prepared CMC/HA-AT beads were investigated, and showed a pH sensitive swelling behavior with maximum its content at pH 6.8. Also, it was found that the swelling ratio of CMC/HNT beads was lower than that of pristine CMC beads. Drug release behavior of CMC/HNT-AT bionanocomposite hydrogel beads were investigated. A more sustained and controlled drug releases were observed for CMC/HNT-AT beads.

Organically modified clay supported chitosan/hydroxyapatite-zinc oxide nanocomposites with enhanced mechanical and biological properties for the application in bone tissue engineering.

The objective of this study is to design biomimetic organically modified montmorillonite clay (OMMT) supported chitosan/hydroxyapatite-zinc oxide (CTS/HAP-ZnO) nanocomposites (ZnCMH I-III) with improved mechanical and biological properties compared to previously reported CTS/OMMT/HAP composite. Fourier transform infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy and transmission electron microscopy were used to analyze the composition and surface morphology of the prepared nanocomposites. Strong antibacterial properties against both Gram-positive and Gram-negative bacterial strains were established for ZnCMH I-III. pH and blood compatibility study revealed that ZnCMH I-III should be nontoxic to the human body. Cytocompatibility of these nanocomposites with human osteoblastic MG-63 cells was also established. Experimental findings suggest that addition of 5wt% of OMMT into CTS/HAP-ZnO (ZnCMH I) gives the best mechanical strength and water absorption capacity. Addition of 0.1wt% of ZnO nanoparticles into CTS-OMMT-HAP significantly enhanced the tensile strengths of ZnCMH I-III compared to previously reported CTS-OMMT-HAP composite. In absence of OMMT, control sample (ZnCH) also showed reduced tensile strength, antibacterial effect and cytocompatibility with osteoblastic cell compared to ZnCMH I. Considering all of the above-mentioned studies, it can be proposed that ZnCMH I nanocomposite has a great potential to be applied in bone tissue engineering.