Methyl Vinyl Ether Maleic Acid Research Articles

INFLUENCE OF ASPECT RATIO OF TEMPO-OXIDIZED CELLULOSE NANOFIBERS (TOCNs) FROM WOOD PULP ON POLYMERIC MEMBRANE PROPERTIES

The incorporation of TEMPO-oxidized cellulose nanofibers (TOCNs) derived from wood pulp resulted in an improvement in the characteristics of polymeric membranes made up of poly (methyl vinyl ether maleic acid)/PMVEMA and poly (ethylene glycol)/PEG. The membranes were constructed, and TOCNs were included in the formulation at a rate of 5 wt%. TOCNs were categorized as either short or long, depending on the aspect ratio measurement. According to the findings of the research, the various lengths of TOCNs resulted in variances in the optical transmittance properties, contact angles, and whiteness level of the membranes, in addition to a little variation in the tensile and thermal properties of the material. When compared to short TOCNs, long TOCNs offer somewhat improved performance in terms of optical transmittance, whiteness level, tensile characteristics, and thermal stability. The results of this study reveal the significance of the morphology of nanocellulose in determining the properties of the composite that includes it. Thus, the characteristics of the target membrane were greatly influenced by nanocellulose morphology.

The Effect of Various Milling Time Duration On The Characteristic of Glass Ionomer Cement (GIC) with The Addition of Liquid Pmve-Ma

A study entitled The Effect of Milling Time Duration on the Characteristics of Glass Ionomer Cement (GIC) Dental Cement with the Addition of Liquid PMVE-MA aims to determine the effect of milling time duration on the physical and mechanical properties of Glass Ionomer Cement, and to determine the optimum milling time duration in order to obtain GIC dental cement with the best characteristic to be applied as a dental restoration material. The duration of the milling time was 80 minutes, 90 minutes, 100 minutes, and 110 minutes. After the milling process, the next process was sintered at a temperature of 1200 for 1 hour to form Powder Glass Ionomer. Then Powder Glass Ionomer was added with Poly Methyl Vinyl Ether-Maleic Acid (PMVE-MA) to form a paste. The mixed paste was then formed. Sample characterization was the density test, the compressive strength test, and the vickers hardness test. The results of the density test obtained the highest value of 1.683 gram / cm3, the compressive strength test of 71.841 MPa, and the highest value of the hardness test of 92.3 Kg / mm2. These results increased as the increasing milling time duration up to 110 minutes.

Optimization of Poly(methyl vinyl ether-co-maleic acid) Electrospun Nanofibers as a Fast-Dissolving Drug Delivery System.

Background:Poly(methyl vinyl ether-maleic acid) (PMVEMA) is a water-soluble, biodegradable polymer used for drug delivery. The aim of the present study was to prepare nanofibers of this polymer as a fast-dissolving carrier for montelukast.Materials and Methods:Polymeric nanofibers were spun by electrospinning method using different ratios of biodegradable polymer of PMVEMA. The processing variables including voltage, distance of the needle to rotating screen, and flow rate of the solution were optimized based on the diameter of the nanofibers, drug content, and release efficiency by a Taguchi design. The morphology, diameter, and diameter distribution of the nanofibers were studied by scanning electron microscopy (SEM). Drug loading and its release rate from the nanofibers were analyzed spectrophotometrically. The possible molecular between the polymer and the drug was characterized with Fourier-transform-infrared spectroscopy.Results:The results showed the best situation for electrospinning of the polymer obtained at the polymer concentration of 37%, the distance of the needle to rotating screen of 19 cm, the voltage of 120 kV, and the rate of injection of 0.2 ml/h. In these situations, the fiber diameter and drug loading efficiency percentage were 273 nm and 83%, respectively. These nanofibers released the total loaded drug within 1–3 s with no residue in the dissolution medium. SEM results showed that the optimized nanofibers were quite smooth and without beads.Conclusions:The results indicated that the nanofibers of PMVEMA could dissolve the drug very rapidly and can be adopted for fast-dissolving dosage forms.

Construction of three-dimensional culture model of human neuroendocrine tumor BON-1 and H727 cell lines

Objective To provide new methods for the study of human neuroendocrine tumor cells in vitro by establishing three-dimensional culture models. Methods Agarose gel, alginate/polyacrylamide copolymer (ALG/PAAm) hydrogel and polyethylene glycol (PEG) crosslinked poly methyl vinyl ether maleic acid alt (PMVE-alt-MA) hydrogel were prepared. Three-dimensional culture models of human neuroendocrine tumor H727 and BON-1 cell lines based on these three materials were constructed, and the morphological changes of the models were observed by a microscope every 24 h. Results The shapes of H727 and BON-1 cells with three-dimensional culture were different from those of two-dimensional culture. After cultured for one week, H727 cells formed different multicellular spheroids with sphere diameter of 350-450, 150-250 and 50-100 μm on agarose gel, ALG/PAAm hydrogel and in PEG crosslinking PMVE-alt-MA hydrogel respectively. And BON-1 cells grew up into multicellular spheroids with sphere diameter of 150-200 μm in PEG crosslinking PMVE-alt-MA hydrogel, but they just formed irregularly shaped multicellular aggregates on the other two culture materials. Conclusion The three materials could be applied for constructing three-dimensional culture models of BON-1 and H727 cell lines. Due to their advantages and disadvantages, the appropriate culture material would be selected according to specific experimental requirements. Key words: Neuroendocrine tumor cell; Three-dimensional culture model; Culture material

Targeted delivery of doxorubicin to breast cancer cells by magnetic LHRH chitosan bioconjugated nanoparticles

The novel dual targeted nanoparticles loaded with doxorubicin (DOX) and magnetic nanoparticles (MNPs) were prepared for treatment of breast cancer. Nanoparticles were produced by a layer-by-layer technique and functionalized with a bioconjugate of chitosan-poly(methyl vinyl ether maleic acid)(PMVMA)-LHRH to target LHRH receptors. The successful production of chitosan-PMVMA copolymer and its conjugation to LHRH was confirmed by FTIR and 1HNMR spectroscopy. Capillary electrophoresis analysis showed 72.51% LHRH conjugation efficiency. Transmission electron microscopy and thermogravimetric analysis showed the entrapment of the MNPs in the core of the nanoparticles and vibrating sample magnetometery confirmed their paramagnetic properties. The iron content of nanoparticles determined by inductively coupled plasma optical emission spectrometry showed to be between 3.5–84%. Particle size, zeta potential, drug entrapment and release efficiency of the nanoparticles were 88.1–182.6nm, 10–30mV, 62.3–87.6% and 79.8–83.4%, respectively. No significant protein binding was seen by nanoparticles. The MTT assay showed in LHRH positive cells of MCF-7 the IC50 of the drug reduced to about 2 fold compared to the free drug. By saturation of LHRH receptors the viable MCF7 cells increased significantly after exposure with the targeted nanoparticles. Therefore, the cellular uptake of the nanoparticles might be done by active endocytosis through the LHRH receptors.

Luteinizing hormone-releasing hormone targeted poly(methyl vinyl ether maleic acid) nanoparticles for doxorubicin delivery to MCF-7 breast cancer cells.

The purpose of this study was to design a targeted anti-cancer drug delivery system for breast cancer. Therefore, doxorubicin (DOX) loaded poly(methyl vinyl ether maleic acid) nanoparticles (NPs) were prepared by ionic cross-linking method using Zn(2+) ions. To optimise the effect of DOX/polymer ratio, Zn/polymer ratio, and stirrer rate a full factorial design was used and their effects on particle size, zeta potential, loading efficiency (LE, %), and release efficiency in 72 h (RE72, %) were studied. Targeted NPs were prepared by chemical coating of tiptorelin/polyallylamin conjugate on the surface of NPs by using 1-ethyl-3-(3-dimethylaminopropyl) carboiimid HCl as cross-linking agent. Conjugation efficiency was measured by Bradford assay. Conjugated triptorelin and targeted NPs were studied by Fourier-transform infrared spectroscopy (FTIR). The cytotoxicity of DOX loaded in targeted NPs and non-targeted ones were studied on MCF-7 cells which overexpress luteinizing hormone-releasing hormone (LHRH) receptors and SKOV3 cells as negative LHRH receptors using Thiazolyl blue tetrazolium bromide assay. The best results obtained from NPs prepared by DOX/polymer ratio of 5%, Zn/polymer ratio of 50%, and stirrer rate of 960 rpm. FTIR spectrum confirmed successful conjugation of triptorelin to NPs. The conjugation efficiency was about 70%. The targeted NPs showed significantly less IC50 for MCF-7 cells compared to free DOX and non-targeted NPs.

Prolonged Hypocalcemic Effect by Pulmonary Delivery of Calcitonin Loaded Poly(Methyl Vinyl Ether Maleic Acid) Bioadhesive Nanoparticles

The purpose of the present study was to design a pulmonary controlled release system of salmon calcitonin (sCT). Therefore, poly(methyl vinyl ether maleic acid) [P(MVEMA)] nanoparticles were prepared by ionic cross-linking method using Fe2+ and Zn2+ ions. Physicochemical properties of nanoparticles were studied in vitro. The stability of sCT in the optimized nanoparticles was studied by electrophoretic gel method. Plasma calcium levels until 48 h were determined in rats as pulmonary-free sCT solution or nanoparticles (25 μg·kg−1), iv solution of sCT (5 μg·kg−1), and pulmonary blank nanoparticles. The drug remained stable during fabrication and tests on nanoparticles. The optimized nanoparticles showed proper physicochemical properties. Normalized reduction of plasma calcium levels was at least 2.76 times higher in pulmonary sCT nanoparticles compared to free solution. The duration of hypocalcemic effect of pulmonary sCT nanoparticles was 24 h, while it was just 1 h for the iv solution. There was not any significant difference between normalized blood calcium levels reduction in pulmonary drug solution and iv injection. Pharmacological activity of nanoparticles after pulmonary delivery was 65% of the iv route. Pulmonary delivery of P(MVEMA) nanoparticles of sCT enhanced and prolonged the hypocalcemic effect of the drug significantly.

Application of New Solid Polymeric Dispersant, Easy-Sperse® P-20 (Spray-Dried Polymer Composites) in Suspension Concentrates and Water Dispersible Granule Formulations—Improvement in Suspensibility and Rain-fastnesss

Abstract Easy-Sperse® P-20 [ES P-20] is a synergistic, spray-dried composite of polyvinyl pyrrolidone (PVP) and partially neutralized methyl vinyl ether maleic acid butyl/ethyl half ester polymer. In this work, ES P-20 was used as an additive in water-based suspension concentrate (SC) and water dispersible granule (WDG) for improving the suspensibility and rain-fastness performance of those samples. SC samples with 40 % Diuron, 30 % Isoproturon, and 40 % Imidacloprid were prepared. The suspensibility, rain-fastness, viscosity, pH, heat-aged stability, and particle size distribution were measured and compared. Our data showed that the use of ES P-20 could improve the SC suspensibility. The majority of the samples tested reached>70 % suspensibility at 0.2 %, 0.5 %, and 1 % active ingredients after dilution with water and after 4 h standing at room temperature. For some samples, the suspensibility was found to be>90 %, while the formulations without ES P-20 showed a suspensibility of <50 % in most cases. After adding ES P-20, the SC sample with 40 % Diuron also demonstrated better rain-fastness. This indicates that ES P-20 can enhance water resistance during water rinsing. WDG samples with 90 % Atrazine, 80 % Diuron, and 75 % Nicosulfuron were also made successfully using ES P-20 as one of the polymeric dispersants via a laboratory basket extruder. Performance data including friability/hardness, disintegration, wetting time, and suspensibility were evaluated. The data provided illustrate the advantage of using ES P-20 for improving the suspensibility in water. In conclusion, ES P-20 shows synergy with anionic dispersants in dispersing AIs. It also improves heat-aged stability and reduces settling of the AI with time. The formulations with ES P-20 showed increased resistance to water wash in our laboratory tests. The results demonstrated that ES P-20 can be used effectively in formulating zero volatile organic compound compositions like SC and WDG.

Polymeric-Calcium Phosphate Cement Composites-Material Properties:In VitroandIn VivoInvestigations

New polymeric calcium phosphate cement composites (CPCs) were developed. Cement powder consisting of 60 wt% tetracalcium phosphate, 30 wt% dicalcium phosphate dihydrate, and 10 wt% tricalcium phosphate was combined with either 35% w/w poly methyl vinyl ether maleic acid or polyacrylic acid to obtain CPC-1 and CPC-2. The setting time and compressive and diametral tensile strength of the CPCs were evaluated and compared with that of a commercial hydroxyapatite cement. In vitro cytotoxicity and in vivo biocompatibility of the two CPCs and hydroxyapatite cement were assessed. The setting time of the cements was 5–15 min. CPC-1 and CPC-2 showed significantly higher compressive and diametral strength values compared to hydroxyapatite cement. CPC-1 and CPC-2 were equivalent to Teflon controls after 1 week. CPC-1, CPC-2, and hydroxyapatite cement elicited a moderate to intense inflammatory reaction at 7 days which decreased over time. CPC-1 and CPC-2 show promise for orthopedic applications.

New Value-Added Polymeric Dispersants and Uses Thereof in Agricultural Formulations

Abstract Polymeric dispersants are dispersants of choice for formulating suspension concentrates, suspoemulsions, and solid delivery systems (WP, WDG, and Tablets). We have developed a new line of polymeric dispersants, as 25 % aqueous solution, based on partially neutralized methyl vinyl ether maleic acid half esters (ethyl/butyl) copolymers (MVE-MAHE), (with trade name EASY-SPERSE®). They were used in formulating suspension concentrates and aqueous dispersions for a host of active ingredients like herbicides, insecticides, fungicides, and other growth regulators, organic dyes, inorganic pigments, including certain water-insoluble polymers. Some of these dispersions also showed suspensibility above 80 % and rainfastness at use level concentrations. Other commonly used polymeric dispersants are: Lignosulfonates, Naphthalene sulfonate formaldehyde condensate (NSFC), Poly acrylates, and olefin maleic acid co-polymers. Their film forming properties and binding efficacy can be improved when used with pyrrolidone co-polymers. Our recent findings show synergy between vinylpyrrolidone homo/co-polymers and commonly used polymeric dispersants as above. Further, a combination of Polyvinylpyrrolidone and polymeric dispersants showed built-in rainfastness in suspension concentrates. Examples of prototype formulations and a working model explaining the synergistic role of polyvinylpyrrolidone are provided. Solid composites from Polyvinylpyrrolidone and MVE-MAHE were prepared via spray drying the liquid slurries. The solid dispersants with Polyvinylpyrrolidone incorporated will be useful in formulating solid delivery systems.

A polymeric solid electrolyte based on a binary blend of poly(ethylene oxide), poly(methyl vinyl ether-maleic acid) and LiClO4

A new polymeric solid electrolyte based on a PEO/PMVE-MAc blend, complexed with LiClO4, was obtained and characterized by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), polarized light optical microscopy, electrochemical impedance and cyclic voltammetry. DSC traces indicated miscibility for all the PSE samples. Crystallinity was suppressed for samples with LiClO4 concentrations higher than 2.5wt%. FTIR associated with DSC studies indicated that there is a preferential formation of complexes PEO/Li+/PMVE-MAc in all PSE samples studied here. The ionic conductivity of PSE reaches a maximum of about 10−5S/cm at ambient temperature and 7.5wt% LiClO4. The electrochemical stability window is 4.5V and associated with the other characteristics, make the PSE studied here suitable for applications in ‘smart-windows’, batteries, sensors, etc.

Miscibility, crystallinity and morphological behavior of binary blends of poly(ethylene oxide) and poly(methyl vinyl ether–maleic acid)

DSC and optical microscopy were used to determine the miscibility and crystallinity of blends of poly(ethylene oxide) (PEO) with poly(methyl vinyl ether– co–maleic acid) (PMVE–MAc). Single T g was observed for all blends, indicating miscibility. The dependence of T g on the weight per cent of PEO presents a negative deviation from linearity at high PEO content, associated to a greater blend free volume, mobility and flexibility than in pure PEO. A progressive decrease in the degree of crystallinity and in the size of the PEO spherullites as the PMVE–MAc is added is observed. FTIR provided evidence of specific interaction between the polymers.

Effect of powder grinding on hydroxyapatite formation in a polymeric calcium phosphate cement prepared from tetracalcium phosphate and poly(methyl vinyl ether-maleic acid)

The primary aim of this study was to determine if cements based on poly(methyl vinyl ether-maleic acid) (PMVE-Ma) and tetracalcium phosphate resulted in hydroxyapatite formation. In addition, the mechanical strength of this type of polymeric calcium phosphate cement was evaluated. Cements were prepared by mixing, in a powder/liquid mass ratio of 3.0, an aqueous solution of PMVE-Ma (mass fraction=25%) and tetracalcium phosphate powders ground for various periods of time. The tetracalcium phosphate powders and set cements were characterized by means of X-ray powder diffraction and scanning electron microscopy. Mechanical strengths of the cements were tested 24 h after mixing. Prolonged grinding of tetracalcium phosphate powder decreased particle size and/or crystallite size and increased lattice distortion. This enhanced the reactivity of the tetracalcium phosphate powder and elevated the extent of crosslinking between PMVE-Ma molecules, resulting in improved mechanical strength. Hydroxyapatite formation was detected in the cement prepared with the most finely ground tetracalcium phosphate powder. The conversion of residual tetracalcium phosphate particles to more thermodynamically stable hydroxyapatite crystals will reduce the solubility of the polymeric cement and increase its biocompatibility.

Polymeric calcium phosphate cements derived from poly(methyl vinyl ether-maleic acid)

Objectives. The purpose of this study was to assess the feasibility of forming polymeric calcium phosphate cements from a mixed powder of dicalcium phosphate/tetracalcium phosphate or only tetracalcium phosphate and poly(methyl vinyl ether-maleic acid) (PMVE-Ma), and to study their setting reaction. Methods. The setting reaction process of the polymeric cements was evaluated by mechanical strength tests, infrared spectroscopy and x-ray diffraction analysis and compared with that of a water-setting calcium phosphate cement. The mechanical strength data were analyzed using ANOVA and Scheffé's multiple comparisons test. Results. Cements prepared from the mixed powder and 25–30 wt% aqueous solutions of PMVE-Ma had high mechanical strength after 24 h storage in distilled water at 37°C. The hardening mechanism dependended on an acid-base reaction between the carboxyl groups of PMVE-Ma and the mixed powder, especially its tetracalcium phosphate component. The formation of hydroxyapatite in the polymeric calcium phosphate cement was not detected and is apparently inhibited as a result of the competing reaction of PMVE-Ma with the mixed powder. Significance. The cement-forming reaction was significantly faster than that of a water-setting calcium phosphate cement and slower than that observed with the mixed powder and polyacids such as poly(acrylic acid). The characteristics of the polymeric cements suggest that the materials may be useful in cavity lining or endodontic sealing.