Characteristics of Interpolyelectrolyte Complexes Based on Different Types of Pectin with Eudragit® EPO as Novel Carriers for Colon-Specific Drug Delivery.

Given that pectin is a well-known substance used for drug delivery, we aimed to obtain and further examine the efficacy of interpolyelectrolyte complexes based on citrus or apple pectin and the Eudragit® EPO for using these carriers in oral drug delivery. To characterize the physicochemical properties of these compounds, turbidity, gravimetry, viscosity, elementary analysis, FTIR spectroscopy, and DSC analysis were utilized. Diffusion transport characteristics were evaluated to assess the swelling ability of the matrices and the release of diclofenac sodium. To examine the release parameters, mathematical modeling was performed by using the Korsmayer-Peppas and Logistic equations as well. During the turbidity study, stoichiometry compositions were selected for the developed IPECs EPO/PecA and EPO/PecC at pH values = 4.0, 5.0, 6.0, and 7.0. The FTIR spectra of the complexes were characterized by an increase in the intensity of the bands at 1610 cm-1 and 1400 cm-1. According to the DSC analysis, IPEC has a certain Tg = 57.3 °C. The highest release rates were obtained for IPEC EPO/PecC_1 and EPO/PecC_4. The mechanism of drug transport from the matrices IPEC EPO/PecC, IPEC EPO/PecA_3, and EPO/PecA_4 can be characterized as Super Case II. Anomalous release (non-Fickian release) is typical for IPEC EPO/PecA_1 and EPO/PecA_2. Thus, the resulting systems can be further used for the effective delivery of the drugs to the colon.

Phosphorus-Containing Polymers as Sensitive Biocompatible Probes for 31P Magnetic Resonance.

The visualization of organs and tissues using 31P magnetic resonance (MR) imaging represents an immense challenge. This is largely due to the lack of sensitive biocompatible probes required to deliver a high-intensity MR signal that can be distinguished from the natural biological background. Synthetic water-soluble phosphorus-containing polymers appear to be suitable materials for this purpose due to their adjustable chain architecture, low toxicity, and favorable pharmacokinetics. In this work, we carried out a controlled synthesis, and compared the MR properties, of several probes consisting of highly hydrophilic phosphopolymers differing in composition, structure, and molecular weight. Based on our phantom experiments, all probes with a molecular weight of ~3-400 kg·mol-1, including linear polymers based on poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC), poly(ethyl ethylenephosphate) (PEEP), and poly[bis(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)]phosphazene (PMEEEP) as well as star-shaped copolymers composed of PMPC arms grafted onto poly(amidoamine) dendrimer (PAMAM-g-PMPC) or cyclotriphosphazene-derived cores (CTP-g-PMPC), were readily detected using a 4.7 T MR scanner. The highest signal-to-noise ratio was achieved by the linear polymers PMPC (210) and PMEEEP (62) followed by the star polymers CTP-g-PMPC (56) and PAMAM-g-PMPC (44). The 31P T1 and T2 relaxation times for these phosphopolymers were also favorable, ranging between 1078 and 2368 and 30 and 171 ms, respectively. We contend that select phosphopolymers are suitable for use as sensitive 31P MR probes for biomedical applications.

Coffee Beverage: A New Strategy for the Synthesis of Polymethacrylates via ATRP.

Coffee, the most popular beverage in the 21st century society, was tested as a reaction environment for activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP) without an additional reducing agent. Two blends were selected: pure Arabica beans and a proportional blend of Arabica and Robusta beans. The use of the solution received from the mixture with Robusta obtained a high molecular weight polymer product in a short time while maintaining a controlled structure of the synthesized product. Various monomers with hydrophilic characteristics, i.e., 2-(dimethylamino)ethyl methacrylate (DMAEMA), oligo(ethylene glycol) methyl ether methacrylate (OEGMA500), and glycidyl methacrylate (GMA), were polymerized. The proposed concept was carried out at different concentrations of coffee grounds, followed by the determination of the molar concentration of caffeine in applied beverages using DPV and HPLC techniques.

MSCs-engineered biomimetic PMAA nanomedicines for multiple bioimaging-guided and photothermal-enhanced radiotherapy of NSCLC.

BACKGROUND: The recently developed biomimetic strategy is one of the mostly effective strategies for improving the theranostic efficacy of diverse nanomedicines, because nanoparticles coated with cell membranes can disguise as "self", evade the surveillance of the immune system, and accumulate to the tumor sites actively. RESULTS: Herein, we utilized mesenchymal stem cell memabranes (MSCs) to coat polymethacrylic acid (PMAA) nanoparticles loaded with Fe(III) and cypate-an derivative of indocyanine green to fabricate Cyp-PMAA-Fe@MSCs, which featured high stability, desirable tumor-accumulation and intriguing photothermal conversion efficiency both in vitro and in vivo for the treatment of lung cancer. After intravenous administration of Cyp-PMAA-Fe@MSCs and Cyp-PMAA-Fe@RBCs (RBCs, red blood cell membranes) separately into tumor-bearing mice, the fluorescence signal in the MSCs group was 21% stronger than that in the RBCs group at the tumor sites in an in vivo fluorescence imaging system. Correspondingly, the T1-weighted magnetic resonance imaging (MRI) signal at the tumor site decreased 30% after intravenous injection of Cyp-PMAA-Fe@MSCs. Importantly, the constructed Cyp-PMAA-Fe@MSCs exhibited strong photothermal hyperthermia effect both in vitro and in vivo when exposed to 808 nm laser irradiation, thus it could be used for photothermal therapy. Furthermore, tumors on mice treated with phototermal therapy and radiotherapy shrank 32% more than those treated with only radiotherapy. CONCLUSIONS: These results proved that Cyp-PMAA-Fe@MSCs could realize fluorescence/MRI bimodal imaging, while be used in phototermal-therapy-enhanced radiotherapy, providing desirable nanoplatforms for tumor diagnosis and precise treatment of non-small cell lung cancer.

Development of a novel intraarticular injection of diclofenac for the treatment of arthritis: a preclinical study in the rabbit model.

PURPOSE: To develop a novel intraarticular injection of diclofenac for the treatment of arthritis. METHOD: Diclofenac loaded nanoparticles were prepared by a nanoprecipitation technique using Eudragit L 100 as the polymer and polyvinyl alcohol as the surfactant. The nanoparticles were evaluated for particle size, zeta potential, scanning electron microscopy, drug release, encapsulation efficiency, and loading efficiency studies. The optimized nanoparticulate formulation was developed for intra articular injection. Intraarticulate injection was evaluated for pH, appearance, viscosity, osmolarity and syringability studies. The optimized injection formulation was tested in an arthritic model consisting of 25 rabbits. RESULT: Nanoprecipitation method was found to be suitable for diclofenac nanoparticles. The shape of the prepared nanoparticles was found to be spherical and devoid of any cracks and crevices. The average particle size of a diclofenac nanoparticle was found to range from 87±0.47 to 103±0.26 nm. The zeta potential of the prepared nanoparticles was found to be in the range of 0.598±0.34 to 0.826±0.25 mV. The encapsulation efficiency was found to be between 73.45% to 99.03%, while the drug loading was observed between 10.34 to 35.32%. The percentage drug release at 12 hours was found to range from 73.45% to 99.03%. CONCLUSION: The developed intraarticular injection was found to be within the physically and chemically accepted limits. Animals treated with the intra articular injection of diclofenac showed a significant reduction in swelling as compares to the other groups.

PMAA-CeO2 nanoparticle-based paper microfluidic device with customized image processing software for antioxidant assay.

Despite recent advancements in the field of microfluidic paper-based analytical devices (µPADs), a key challenge remains in developing a simple and efficient µPAD with customized imaging capabilities for antioxidant assays. In the present study, we report a facile approach for µPAD fabrication through the application of transparent nail paint leading to creation of hydrophobic barriers and well-defined channels. The resultant µPADs were then characterized through scanning electron microscopy and contact angle measurements. The resolution and functional features of the fabricated µPAD were amenable to the intended assay. The µPAD's impregnated poly(methacrylic acid) (PMAA)-coated cerium oxide (CeO2) nanoparticles oxidized the 3,3',5,5'-tetramethylbenzidine (TMB) leading to the formation of a blue-colored charge-transfer complex. The addition of different antioxidant standard solutions resulted in a reduction in the blue color in a dose-dependent manner which could be observed visually. The color intensity of the PMAA-CeO2 nanoparticle@TMB oxidation product was inversely proportional to the antioxidant concentration and was measured using customized in-house MATLAB-based image processing software. Importantly, PMAA-CeO2 nanoparticle-based µPADs demonstrated good analytical characteristics and were able to be stored for long periods without any loss of activity. Moreover, potential interferents did not pose any threat to the colorimetric signal read-out for determination of antioxidant activity. The developed method was further applied for the assessment of antioxidant activity in a variety of tea samples and performed satisfactorily in comparison with a commonly used antioxidant detection method. Collectively, the developed µPAD-based platform holds great potential as a low-cost, convenient, portable and reliable method for pursuing various on-site antioxidant assays. Graphical Abstract.

Synthesis and characterization of thermo/pH-sensitive pectin-graft-poly(dimethylaminoethyl methacrylate) coated magnetic nanoparticles.

Herein, thermo- and pH-sensitive pectin-graft-poly(dimethylaminoethyl methacrylate) copolymer-coated magnetic nanoparticles were synthesized via a green and rapid synthetic approach based on microwave irradiation. Firstly, a novel thermo- and pH-sensitive pectin-graft-poly(dimethylaminoethyl methacrylate) copolymer (Pec-g-PolyDMAEMA) was synthesized and then, Pec-g-PolyDMAEMA based magnetic nanoparticles (Pec-g-PolyDMAEMA@Fe3O4) were produced via microwave-assisted co-precipitation method. The thermo/pH/magnetic field multi-sensitive hybrid nanoparticle was characterized by techniques like TEM, VSM, FT-IR, and TGA/DSC. In vitro release studies of 5-Fluorouracil (FL) were carried out by altering the temperature (37 and 44°C), pH (5.5 and 7.4) and presence of an AMF. The FL release of Pec-g-PolyDMAEMA@Fe3O4@FL exhibited pH-sensitive behavior. They showed thermo/pH-sensitive FL release features with the greatest release of FL at 37°C (56%) than at 44°C (40%) and at pH of 7.4 (63%) than at pH of 5.5 (45%) within 48h. The FL release was also significantly increased (100%) with the presence of a 50 mT magnetic field. These results indicate that the developed Pec-g-PolyDMAEMA@Fe3O4 nanoparticles are promising in the application of multi-stimuli-sensitive delivery of drugs.

Enhanced therapeutic efficacy of a novel colon-specific nanosystem loading emodin on DSS-induced experimental colitis.

BACKGROUND: Ulcerative colitis (UC) is an intricate enteric disease with a rising incidence that is closely related to mucosa-barrier destruction, gut dysbacteriosis, and immune disorders. Emodin (1,3,8-trihydroxy-6-methyl-9,10-anthraquinone, EMO) is a natural anthraquinone derivative that occurs in many Polygonaceae plants. Its multiple pharmacological effects, including antioxidant, immune-suppressive, and anti-bacteria activities, make it a promising treatment option for UC. However, its poor solubility, extensive absorption, and metabolism in the upper gastrointestinal tract may compromise its anti-colitis effects. PURPOSE: EMO was loaded in a colon-targeted delivery system using multifunctional biomedical materials and the enhanced anti-colitis effect involving mucosa reconstruction was investigated in this study. METHODS: EMO-loaded Poly (DL-lactide-co-glycolide)/EudragitⓇ S100/montmorillonite nanoparticles (EMO/PSM NPs) were prepared by a versatile single-step assembly approach. The colon-specific release behavior was characterized in vitro and in vivo, and the anti-colitis effect was evaluated in dextran sulfate sodium (DSS)-induced acute colitis in mice by weight loss, disease activity index (DAI) score, colon length, histological changes, and colitis biomarkers. The integrity of the intestinal mucosal barrier was evaluated through transwell co-culture model in vitro and serum zonulin-related tight junctions and mucin2 (MUC2) in vivo. RESULTS: EMO/PSM NPs with a desirable hydrodynamic diameter (~ 235 nm) and negative zeta potential (~ -31 mV) could prevent the premature drug release (< 4% in the first 6 h in vitro) in the upper gastrointestinal tract (GIT) and boost retention in the lower GIT and inflamed colon mucosa in vivo. Compared to free EMO-treatment of different doses in UC mice, the NPs could enhance the remedial efficacy of EMO in DAI decline, histological remission, and regulation of colitis indicators, such as myeloperoxidase (MPO), nitric oxide (NO), and glutathione (GSH). The inflammatory factors including induced nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), TNF-α, and IL-1ß were suppressed by EMO/PSM NPs at both mRNA and protein levels. The obtained NPs could also promote the regeneration of the mucosal barrier via reduced fluorescein isothiocyanate (FITC)-dextran leakage in the transwell co-culture model and decreased serum zonulin levels, which was demonstrated to be associated with the upregulated tight junctions (TJs)-related proteins (claudin-2, occludin, and zo-1) and MUC2 at mRNA level. Moreover, the NPs could contribute to attenuating the liver injury caused by free EMO under excessive immune inflammation. CONCLUSION: Our results demonstrated that EMO/PSM NPs could specifically release EMO in the diseased colon, and effectively enhance the anti-colitis effects of EMO related to intestinal barrier improvement. It can be considered as a novel potential alternative for oral colon-targeted UC therapy by increasing therapeutic efficacy and reducing side-effects.

Preparation of Poly(glycidyl methacrylate) (PGMA) and Amine Modified PGMA Adsorbents for Purification of Glucosinolates from Cruciferous Plants.

Glucosinolates (GLs) are of great interest for their potential as antioxidant and anticancer compounds. In this study, macroporous crosslinked copolymer adsorbents of poly (glycidyl methacrylate) (PGMA) and its amine (ethylenediamine, diethylamine, triethylamine)-modified derivatives were prepared and used to purify the GLS glucoerucin in a crude extract obtained from a cruciferous plant. These four adsorbents were evaluated by comparing their adsorption/desorption and decolorization performance for the purification of glucoerucin from crude plant extracts. According to the results, the strongly basic triethylamine modified PGMA (PGMA-III) adsorbent showed the best adsorption and desorption capacity of glucoerucin, and its adsorption data was a good fit to the Freundlich isotherm model and pseudo-second-order kinetics; the PGMA adsorbent gave the optimum decolorization performance. Furthermore, dynamic adsorption/desorption experiments were carried out to optimize the purification process. Two glass columns were serially connected and respectively wet-packed with PGMA and PGMA-III adsorbents so that glucoerucin could be decolorized and isolated from crude extracts in one process. Compared with KCl solution, aqueous ammonia was a preferable desorption solvent for the purification of glucoerucin and overcame the challenges of desalination efficiency, residual methanol and high operation costs. The results showed that after desorption with 10% aqueous ammonia, the purity of isolated glucoerucin was 74.39% with a recovery of 80.63%; after decolorization with PGMA adsorbent, the appearance of glucoerucin was improved and the purity increased by 11.30%. The process of using serially connected glass columns, wet-packed with PGMA and PGMA-III, may provide a simple, low-cost, and efficient method for the purification of GLs from cruciferous plants.

Halloysite nanotube-embedded microparticles for intestine-targeted co-delivery of biopharmaceuticals.

Microparticles (MPs) with pH-responding macropores have recently proved their significance for the delivery of vulnerable biomolecules for oral drug administration. The previous MP systems were proven to provide enhanced protection against the gastric environment, however, their application is hindered due to insufficient loading efficiencies and deficient penetration capabilities of encapsulated drugs across the mucus barrier. Here, we report a new co-delivery approach based on amine-functionalized halloysite nanotube (HNT)-embedded MPs (amine-HNT-MPs) with pH-responding macropores specifically designed to deal with the mucus barrier at the absorption site. The mean diameter and polydispersity index of the pored MPs were measured by a particle size analyzer to be 37.6 ± 1.3 µm and 1.15, respectively. The drug loading capacity of the co-delivery system was shown to be 50-times higher than previously reported pored MPs. Fluorescence microscopy analysis of sulforhodamine B (into a hollow interior of HNTs)/ fluorescent nanoparticles (into a hollow interior of MPs)-encapsulated MPs confirmed biphasic release behavior due to pH-dependent pore closing/opening in the simulated gastrointestinal (GI) digestive conditions. To verify the protective effect of the co-delivery system, bromelain and lactase were loaded into HNTs and MPs, respectively, and found to exhibit 94.5 ± 3.3% (bromelain) and 70 ± 14.1% (lactase) functional activity in simulated GI tract conditions. The considerable improvement in the stability of the encapsulated enzymes against gastric conditions are attributed to the efficient pore sealing of the co-delivery system after the encapsulation of enzymes and maintenance of these closed pores in the gastric environment. Furthermore, the mucolytic enzyme (i.e. bromelain)-encapsulated co-delivery system was found to enhance mucopenetration of the encapsulated drug from histological analysis using ex vivo porcine intestine tissue. Therefore, the new microencapsulation design proposed in this study provides a promising solution to the major issues hampering the wide-spread application of MPs in the development of oral drug formulations for biopharmaceuticals and vaccines.

Raft-forming gastro-retentive formulations based on Centella asiatica extract-solid dispersions for gastric ulcer treatment.

Liquid raft-forming formulations comprising solid dispersions of glycoside-rich Centella asiatica extract and Eudragit® EPO (GR-SD) were developed to achieve prolonged delivery of the glycosides, asiaticoside (AS) and madecassoside (MS) in the stomach and thus increase the effectiveness of gastric ulcer treatment. Solid dispersions of GR extract and Eudragit® EPO (GR-SD, weight ratio 1:0.5) resulted in the highest solubility of AS (41.7 mg/mL) and MS (29.3 mg/mL) and completed dissolution of both glycosides occurred in SGF within 10 min. The optimized raft-forming formulation was composed of alginate (2%), HPMC K-100 (0.5%), GR-SD (1.2%), and calcium carbonate (0.5%) as a calcium source and carbon dioxide producer. The formulation provided sufficient raft strength (> 7.0 g), rapid floating behavior in SGF (~30 s), and sustained release of AS (more than 80%) and MS (85%) over 8 h. GR-SD-based formulations administered once daily to rats for two days at a dose of 10 mg AS/kg reduced the severity of gastric ulcer induced by indomethacin with a greater curative efficacy than those of unformulated GR extract and a standard antiulcer agent: lansoprazole (p < 0.05). These findings demonstrate that GR-SD-based raft-forming systems offer significant promise for improving the treatment of gastric ulcers induced by non-steroidal anti-inflammatory drugs.

Desonide nanoencapsulation with açai oil as oil core: Physicochemical characterization, photostability study and in vitro phototoxicity evaluation.

This study aimed to develop Eudragit® RL 100 nanocapsules loaded with desonide (DES) using açai oil (AO) or medium chain triglycerides (MCT) as oil core. Pre-formulation study showed that AO and MCT are suitable for nanocapsules preparation. The nanocapsules prepared with AO and MCT presented mean particle size around 165 and 131 nm, respectively; polydispersity index values <0.20, positive zeta potential values, drug content close to the theoretical value (0.25 mg mL-1), and DES encapsulation efficiency around 81%, regardless of the oil core (AO or MCT). Considering the photoinstability reported to DES, photodegradation studies were performed. The UV-A (365 nm) and UV-C (254 nm) photodegradation studies revealed less DES degradation when associated to the nanocapsules containing AO in comparison to those with MCT. The in vitro release study showed a biphasic release profile for both nanocapsule suspensions: an initial burst effect followed by a prolonged DES release. In addition, the formulations were considered non-phototoxic at 0.5 mg mL-1 when tested on 3 T3 murine fibroblasts and HaCaT human keratinocytes using the MTT and NRU viability assays. The irritant potential of the prepared nanocapsules and DES in free form were evaluated by HET-CAM method. All formulations were classified as slightly irritant, including the non-associate DES. In conclusion, the nanocapsule formulations developed in this study may be promising for therapeutic applications.

Low-dose curcumin-loaded Eudragit L-100-nanocapsules in the diet of dairy sheep increases antioxidant levels and reduces lipid peroxidation in milk.

The main objective of this study was to evaluate whether the addition of curcumin-loaded nanocapsules (prepared and characterized) in the diets of dairy sheep improved milk quality. The nanocapsules were prepared using two polymers: poly-ε-caprolactone (PCL) and Eudragit L-100. The nanocapsules contained 0.25 mg/ml (Nano-Eudragit L-100) and 2 mg/ml (Nano-PCL) of curcumin. Dairy sheep were divided into four groups: A (control), B (30 mg free curcumin/kg concentrate), C (3 mg Nano-PCL/kg concentrate), and D (3 mg Nano-Eudragit/kg concentrate). We observed that the number of total leukocytes and serum globulin levels were lower in Group D than in the control (Group A) (p < 0.05). Antioxidant capacity against peroxyl radicals (ACAP) and catalase enzymes was elevated in Group D, with consequently reduced lipid peroxidation (LPO; p < 0.05). In milk, there were no differences in production and composition between groups during the experimental period (p > 0.05); however, ACAP increased and LPO decreased in milk. PRACTICAL APPLICATIONS: Curcumin is a functional molecule with potent antioxidant, anti-inflammatory, and antimicrobial actions, used frequently and with medical indications in human food. Free curcumin in sheep diets improves milk quality and increases its shelf life. This study showed that curcumin nanocapsules produced from the Eudragit L-100 polymer potentiated the anti-inflammatory and antioxidant actions of dairy sheep when used in the diet daily, at doses 10 times lower than that of free curcumin. These positive effects were reflected in higher total antioxidant capacity and lower lipid peroxidation in milk in sheep-fed curcumin-loaded Eudragit L-100 nanocapsules, generating desirable milk properties. In practice, the use of nanotechnology enhances the beneficial effects of curcumin in milk, possibly creating a nutraceutical food desirable to consumers.

Combination of a hot-melt subcoating and an enteric coating for moisture protection of hygroscopic Sennae fructus tablets.

The objective of this study was to investigate the efficiency of moisture protection of hot-melt coatings solely and in combination with an enteric coating on hygroscopic tablet cores containing a spray-dried Sennae fructus extract. Tablet cores were subcoated with different hot-melt coating materials: medium chain tryglycerides, stearic acid, Precirol® ATO 5, and Compritol® 888 ATO, at varying amounts and coated with Eudragit® L 30D-55 for enteric resistance. Subcoating penetration, tablet disintegration, dissolution times, tablet hygroscopicity, and tablet properties such as weight, height, diameter, and hardness were analyzed. 3 mg/cm2 of tablet surface seemed to be sufficient if sustained release is not required. Thereby, hot-melt coating did not adversely affect the tablet properties with regard to subsequent processing steps. Compared to the tablet cores it was possible to reduce the moisture uptake by 85% at 75% relative humidity with tablets coated with a combination of Precirol® ATO 5 and Eudragit® L 30D-55. This combination was more efficient than high amounts of Eudragit® L 30D-55. Hot-melt coating proved to be a suitable technique for the application of subcoating material to tablet cores serving as a barrier against water permeation into hygroscopic tablet cores without exceeding the required disintegration times.

Modeling based experimental investigation on polymerization shrinkage and micro-hardness of nano alumina filled resin based dental material.

This paper investigates the effect of %wt composition of BisGMA/TEGDMA, stirring time, bench time, curing time and filler loading on polymerization shrinkage and micro-hardness of resin based dental composites. The investigation was carried out in two stages. In first stage, samples were prepared with different %wt composition of BisGMA/TEGDMA, stirring time, bench time, and curing time to access the effect of different input parameters for minimum polymerization shrinkage and maximum micro-hardness using Taguchi methodology. Selecting optimum values of input factors from first stage, second stage optimization was performed to investigate the effects of different filler loading on different %wt composition of BisGMA/TEGDMA using full factorial design. Prediction model was developed using Design Expert software and analysis of effect of input parameters on output responses were carried out using 3D surface plots. ANOVA were performed to check the significance of prediction model. In first stage, optimum stirring time, bench time and curing time were found to be 4 h, 50 min and 30 s, respectively. In second stage, optimum polymerization shrinkage and micro-hardness of 3.54% and 310 Hv were predicted at 22.89% of TEGDMA content and 20% filler loading. Taguchi methodology and full factorial design were successfully implemented to access the effect of multi-input parameters on responses for resin based dental composites.

Blend of cellulose ester and enteric polymers for delayed and enteric coating of core tablets of hydrophilic and hydrophobic drugs.

The focus of this work was to explore feasibility of using blends of cellulose esters (CA 320S, CA 3980-10 or CAB 171-15) and enteric polymers (C-A-P, Eudragit® L100 or HPMCP HP-55) for delayed and enteric coating of tablets containing either diclofenac sodium (DFS, high dose) or prednisone (PDS, low dose) drug. The core tablets of DFS or PDS were coated with polymer blends to achieve approximate weight gain of 5% and 10%. The coated tablets were characterized for dissolution (0.1 N HCl and phosphate buffer pH 6.8) and surface morphology. The surface morphology of CA 398-10 or CAB 171-15 based polymer blends was rough and fibrous. Less than 0.5% drug was dissolved in 120 min from 5% w/w coated tablets in acid-phase dissolution testing. The dissolution in phosphate buffer pH 6.8 medium varied from 16.2 ±â€¯0.2 to 98 ±â€¯2.1%, and 30.1 ±â€¯0.5% to 101.7 ±â€¯3.4% in 120 min from DFS and PDS coated tablets, respectively. Dissolution was less in CA 320S based blends compared to CA 398-10 or CAB 171-15 blends in phosphate buffer medium. Furthermore, there were no significant differences observed in dissolution profiles of coated tablets of DFS or PDS. This can be explained by dose of the drugs. Additionally, dissolution was higher in tablets coated with enteric polymer alone compared with the blends. In conclusion, core tablets can be coated with cellulose ester and enteric polymers blend to impart both delayed and enteric release feature to the tablets containing hydrophilic or hydrophobic drug.

Effect of free and nano-encapsulated curcumin on treatment and energetic metabolism of gerbils infected by Listeria monocytogenes.

Bacterial infections require special care since the indiscriminate use of antibiotics to treat them has been linked to the emergence of resistant strains. In this sense, phytoterapeutic alternatives such as curcumin and its nanocapsules have emerged as a promising supplement in optimizing availability of bioactives and reducing the development of antimicrobial resistance. Thus, the aim of this study was to verify the effects of pure and nanoencapsulated curcumin in the treatment of experimental listeriosis in gerbils regarding many aspects including antibacterial effect, antioxidant mechanisms involved and the energetic metabolism. Four groups were used containing 6 animals each: T0 (control), T1 (infected), T2 (infected and treated with free curcumin - dose of 30 mg/kg/day) and T3 (infected and treated with nanocapsules containing curcumin - a dose of 3 mg/kg/day). Treated animals received curcumin for 6 consecutive days starting 24 h after Listeria monocytogenes infection. All animals were euthanized on the 12th day after L. monocytogenes infection. Quantitative polymerase chain reaction (qPCR) identified L. monocytogenes DNA in the spleens of all animals of the T1 group, as well as T2 (2 out of 6) and T3 (5 out of 6). The weight of the spleens confirmed the infection, since it was larger in the T1 group, differing statistically from T0, and similarly to T2 and T3. Hepatic histopathological examination showed mild infiltration of neutrophils and macrophages, except for the T3 group (only 1/6). In the liver, the pyruvate kinase activity was higher in T1 and T2 compared to T0 and T3. The adenylate kinase activity did not differ between groups. The Na+/K+ATPase activity was lower in T1 group compared to T0 and T3. Lipoperoxidation was lower in the T3 group compared to groups T0, T1 and T2. The antioxidant capacity against peroxyl radicals was higher in T1, T2 and T3 groups compared to T0. In conclusion, free curcumin showed potent antibacterial effects; however, the nanoencapsulated form was able to minimize the effects caused by L. monocytogenes regarding tissue injury, changes on enzymes of the energetic metabolism, in addition to an antioxidant effect against lipoperoxidation.

Bioinspired Polydopamine/Polyzwitterion Coatings for Underwater Anti-Oil and -Freezing Surfaces.

Zwitterionic polymers are continually suggested as promising alternatives to tune the surface/interface properties of materials in many fields because of their unique molecular structures. Tremendous efforts have been devoted to immobilizing zwitterionic polymers (polyzwitterions, PZIs) on the material surfaces. However, these efforts usually suffer from cumbersome and time-consuming procedures. Herein we report a one-step strategy to facilely achieve the bioinspired polydopamine/polyzwitterion (PDA/PZI) coatings on various substrates. It requires only 30 min to form PDA/PZI coatings by mixing oxidant, dopamine, and zwitterionic monomers, including carboxybetaine methacrylate (CBMA), sulfobetaine methacrylate (SBMA), and 2-methacryloxyethyl phosphorylcholine (MPC). These bioinspired coatings display multifunctional properties such as underwater antioil-adhesion and antifreezing thanks to their high hydrophilicity and underwater superoleophobicity. The coatings even show the antiadhesion property for crude oil with high viscosity. Therefore, the PDA/PZI-coated meshes are efficient for separating both light oil and crude oil from oil/water mixtures. All these results demonstrate that the one-step strategy is a facile approach to design and exploit the bioinspired PDA/PZI coatings for diverse applications.

Eudragit®-based microcapsules of probucol with a gut-bacterial processed secondary bile acid.

AIM: Deoxycholic acid (DCA) has improved gliclazide oral absorption, while Eudragit® (ED) polymers have improved formulation stability of antidiabetic drugs. The aim of the study is to test if DCA and ED encapsulation will optimize the release and stability of the potential antidiabetic drug probucol (PB). MATERIALS & METHODS: The PB formulations were prepared using ED polymers and DCA, and formulations were analyzed for their rheological and biological properties. RESULTS: Rheological properties and size distribution were similar among all groups. ß-cell survival and biological activities were best with NM30D microcapsules. The inflammatory profile and oxidative stress effects of microcapsules remained similar among all groups. CONCLUSION: ED NM30D and DCA incorporation can exert positive and stabilizing effects on PB oral microcapsules.

Evaluation of biocompatible monomers as substitutes for TEGDMA in resin-based dental composites.

This works reports the synthesis and characterization of diallyl(5-(hydroxymethyl)-1,3-phenylene) dicarbonate (HMFBA) and 5-(hydroxymethyl)-1,3-phenylene bis(2-methylacrylate) (HMFBM) monomers and its evaluation as Bis-GMA eluents in the formulation of composite resins for dental use. The experimental materials formulated with HMFBA and HMFBM monomers presented flexural strength values similar to those of the control group formulated with Bis-GMA/TEGDMA. Regarding volumetric contraction percentage, the values obtained of experimental materials with HMFBA was 1.88% and for HMFBM was 4.15%, both lower than control resin (4.68%). In the case of double bond conversion, the resin formulated with HMFBA monomer exhibited a greater degree of conversion (87%). Besides, the DMA analyses proved that the values for Tg guarantee a good mechanical performance at body temperature. The new resins formulated with HMFBA and HMFBM monomers exhibit a cellular viability close to 100%, which indicates the absence of cytotoxicity towards fibroblastic cells.