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New magnetic oil palm fiber activated carbon-reinforced polypyrrole solid phase extraction combined with gas chromatography-electron capture detection for determination of organochlorine pesticides in water samples

Marsin FM, Wan Ibrahim WA, Nodeh HR, Sanagi MM

J Chromatogr A, 2020 Feb 08;1612:460638.
PMID: 31676087 DOI: 10.1016/j.chroma.2019.460638

Magnetic solid phase extraction (MSPE) employing oil-palm fiber activated carbon (OPAC) modified with magnetite (Fe3O4) and polypyrrole (OPAC-Fe3O4-PPy) was successfully used for the determination of two organochlorine pesticides (OCPs), namely endosulfan and dieldrin in environmental water samples. Analysis was performed using gas chromatography with micro-electron capture detection (GC-μECD). The effects of three preparation variables, namely Fe3O4:OPAC ratio, amount of pyrrole monomer, and amount of FeCl3 oxidant were optimized using Box-Behnken design (BBD) (R2 < 0.99, p-value < 0.001%). The optimum conditions were as follows: Fe3O4:OPAC ratio of 2:1 w/w, 1 g of FeCl3 and 100 μL of pyrrole monomer. The experimental results obtained agreed satisfactorily with the model prediction (> 90% agreement). Optimized OPAC-Fe3O4-PPy composite was characterized using field emission scanning electron microscope, vibrating sample magnetometer and Fourier transform infrared spectroscopy. Four numerical parameters of MSPE procedure was optimized using BBD. The significance of the MSPE parameters were salt addition > sample solution pH > extraction time and desorption time. Under the optimized conditions (extraction time: 90 s, desorption time: 10 min, salt: 0%, and pH: 5.8), the method demonstrated good linearity (25-1000 ng L-1) with coefficients of determination, R2 > 0.991, and low detection limits for both endosulfan (7.3 ng L-1) and dieldrin (8.6 ng L-1). The method showed high analyte recoveries in the range of 98.6-103.5% for environmental water samples. The proposed OPAC-Fe3O4-PPy MSPE method offered good features such as sustainability, simplicity, and rapid extraction.

Matched MeSH terms: Polymers
Voltammetric sensing of formaldehyde by using a nanocomposite prepared by reductive deposition of palladium and platinum on polypyrrole-coated nitrogen-doped reduced graphene oxide

Mahmoudian MR, Basirun WJ, Woi PM, Hazarkhani H, Alias YB

Mikrochim Acta, 2019 05 22;186(6):369.
PMID: 31119482 DOI: 10.1007/s00604-019-3481-y

The study presents the synthesis of polypyrrole-coated palladium platinum/nitrogen-doped reduced graphene oxide nanocomposites (PdPt-PPy/N-rGO NC) via direct the reduction of Pd(II) and Pt(II) in the presence of pyrrole monomer, N-rGO and L-cysteine as the reducing agent. X-ray diffraction confirmed the presence of metallic Pd and Pt from the reduction of Pd and Pt cations. Transmission electron microscopy images revealed the presence of Pd, Pt and PPy deposition on N-rGO. Impedance spectroscopy results gave a decreased charge transfer resistance due to the presence of N-rGO. The nanocomposites were synthesized with different Pd/Pt ratios (2:1, 1:1 and 1:2). A glassy carbon electrode (GCE) modified with the nanocomposite showed enhanced electrochemical sensing capability for formaldehyde in 0.1 M sulfuric acid solution. Cyclic voltammetry showed an increase in the formaldehyde oxidation peak current at the GCE modified with Pd2Pt1 PPy N-rGO. At a typical potential of 0.45 V (vs. SCE), the sensitivity in the linear segment was 345.8 μA.mM -1. cm-2. The voltammetric response was linear between 0.01 and 0.9 mM formaldehyde concentration range, with a 27 µM detection limit (at S/N = 3). Graphical abstract Schematic presentation of formaldehyde detection by Pd2Pt1-PPy/nitrogen-doped reduced Graphene Oxide Nanocomposite (Pd2Pt1-PPy /N-Gr NC). The decrease of charge transfer resistance and the agglomeration of deposited metals in the presence of N-rGO enhance the current response of the electrochemical sensor.

Matched MeSH terms: Polymers
Fulltext The Role of Two-Step Blending in the Properties of Starch/Chitin/Polylactic Acid Biodegradable Composites for Biomedical Applications

Olaiya NG, Nuryawan A, Oke PK, Khalil HPSA, Rizal S, Mogaji PB, et al.

Polymers (Basel), 2020 Mar 05;12(3).
PMID: 32151004 DOI: 10.3390/polym12030592

The current research trend for excellent miscibility in polymer mixing is the use of plasticizers. The use of most plasticizers usually has some negative effects on the mechanical properties of the resulting composite and can sometimes make it toxic, which makes such polymers unsuitable for biomedical applications. This research focuses on the improvement of the miscibility of polymer composites using two-step mixing with a rheomixer and a mix extruder. Polylactic acid (PLA), chitin, and starch were produced after two-step mixing, using a compression molding method with decreasing composition variation (between 8% to 2%) of chitin and increasing starch content. A dynamic mechanical analysis (DMA) was used to study the mechanical behavior of the composite at various temperatures. The tensile strength, yield, elastic modulus, impact, morphology, and compatibility properties were also studied. The DMA results showed a glass transition temperature range of 50 °C to 100 °C for all samples, with a distinct peak value for the loss modulus and factor. The single distinct peak value meant the polymer blend was compatible. The storage and loss modulus increased with an increase in blending, while the loss factor decreased, indicating excellent compatibility and miscibility of the composite components. The mechanical properties of the samples improved compared to neat PLA. Small voids and immiscibility were noticed in the scanning electron microscopy images, and this was corroborated by X-ray diffraction graphs that showed an improvement in the crystalline nature of PLA with starch. Bioabsorption and toxicity tests showed compatibility with the rat system, which is similar to the human system.

Matched MeSH terms: Polymers
Fulltext A Statistical Study on the Development of Metronidazole-Chitosan-Alginate Nanocomposite Formulation Using the Full Factorial Design

Sabbagh HAK, Hussein-Al-Ali SH, Hussein MZ, Abudayeh Z, Ayoub R, Abudoleh SM

Polymers (Basel), 2020 Apr 01;12(4).
PMID: 32244671 DOI: 10.3390/polym12040772

The goal of this study was to develop and statistically optimize the metronidazole (MET), chitosan (CS) and alginate (Alg) nanoparticles (NP) nanocomposites (MET-CS-AlgNPs) using a (21 × 31 × 21) × 3 = 36 full factorial design (FFD) to investigate the effect of chitosan and alginate polymer concentrations and calcium chloride (CaCl2) concentration ondrug loading efficiency(LE), particle size and zeta potential. The concentration of CS, Alg and CaCl2 were taken as independent variables, while drug loading, particle size and zeta potential were taken as dependent variables. The study showed that the loading efficiency and particle size depend on the CS, Alg and CaCl2 concentrations, whereas zeta potential depends only on the Alg and CaCl2 concentrations. The MET-CS-AlgNPs nanocomposites were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM) and in vitro drug release studies. XRD datashowed that the crystalline properties of MET changed to an amorphous-like pattern when the nanocomposites were formed.The XRD pattern of MET-CS-AlgNPs showed reflections at 2θ = 14.2° and 22.1°, indicating that the formation of the nanocompositesprepared at the optimum conditions havea mean diameter of (165±20) nm, with a MET loading of (46.0 ± 2.1)% and a zeta potential of (-9.2 ± 0.5) mV.The FTIR data of MET-CS-AlgNPs showed some bands of MET, such as 3283, 1585 and 1413 cm-1, confirming the presence of the drug in the MET-CS-AlgNPs nanocomposites. The TGA for the optimized sample of MET-CS-AlgNPs showed a 70.2% weight loss compared to 55.3% for CS-AlgNPs, and the difference is due to the incorporation of MET in the CS-AlgNPs for the formation of MET-CS-AlgNPs nanocomposites. The release of MET from the nanocomposite showed sustained-release properties, indicating the presence of an interaction between MET and the polymer. The nanocomposite shows a smooth surface and spherical shape. The release profile of MET from its MET-CS-AlgNPs nanocomposites was found to be governed by the second kinetic model (R2 between 0.956-0.990) with more than 90% release during the first 50 h, which suggests that the release of the MET drug can be extended or prolonged via the nanocomposite formulation.

Matched MeSH terms: Polymers
Comparative study of poly(4-vinylpyridine) and polylactic acid-block-poly(2-vinylpyridine) nanocomposites on structural, morphological and electrochemical properties

Jiajia L, Azlin Suhaida Azmi, Kim Minsoo P, Fathilah Ali

Sains Malaysiana, 2017;46:1097-1102.

Polymer-based nanocomposites have attracted a lot of attention for amperometric biosensor development due to their general physical and chemical properties including biocompatibility, film-forming ability, stability and different functional groups that can be bonded with other biomolecues. In this study, poly-4-vinlyridine homopolymer (P4VP) and polylactic acid-block-poly(2-vinylpyridine) block copolymer (PLA-b-P2VP) were used to hybridize with gold precursors (Au3+) based on the association between the nitrogen of the pyridine group of P4VP or P2VP block with gold precursors. P4VP/Au3+ and PLA-b-P2VP/Au3+ nanocomposites were prepared with ratio of gold to P2VP or P4VP (10:1). The Au3+ in both polymers was reduced to gold nanoparticles (AuNPs) via in-situ approach by using hydrazine. Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-vis), transmission electron microscopy (TEM) and cyclic voltammetry (CV) were used to characterize the structural, morphological and electrochemical properties of the nanocomposites. The peak currents of P4VP/AuNPs and PLA-b-P2VP/AuNPs nanocomposites modified electrode were 6.685 nA and 69.432 nA, respectively, which are much lower than bare electrode (205.019 nA) due to the non-conductivity of P4VP and PLA-b-P2VP. In order to improve the electron transfer capability of electrode, graphene oxide (GO) was blended and electrochemically reduced to obtain P4VP/AuNPs/rGO and PLA-b-P2VP/AuNPs/rGO nanocomposites. After immobilization of these two nanocomposites on electrode through drop casting method, the peak currents of P4VP/AuNPs/rGO and PLA-b-P2VP/AuNPs/rGO nanocomposites modified electrode were 871.172 nA and 663.947 nA, respectively, which are much higher than bare electrode (205.019 nA) and shown good capability to accelerate electron transfer. Based on these characterizations, P4VP/AuNPs/rGO has potential as the nanocomposite to modify the electrode for enzymatic biosensor development.

Matched MeSH terms: Polymers
Highly porous chitosan beads embedded with silver-graphene oxide nanocomposites for antibacterial application

Chook SW, Chia CH, Hatika Kaco, Sarani Zakaria, Huang NM, Neoh HM

Sains Malaysiana, 2016;45:1663-1667.

Incorporation of silver nanomaterial into polymer matrix can further accomplished their potential usage in real life
applications. In our previous study, silver nanoparticles (AgNPs) and silver-graphene oxide nanocomposites (AgGO)
were prepared via a rapid microwave-assisted method. Hereby, the as-synthesized AgNPs or AgGO was dispersed in a
chitosan solution. Subsequently, the resultant mixture solution was further coagulated in a coagulation bath containing
sodium hydroxide via a neutralization process. This resulted in the formation of spherical-shaped chitosan beads.
The structure of the beads showed that the chitosan beads embedded with AgGO exhibited a more porous structure as
compared to the plain chitosan beads. Furthermore, the chitosan beads containing AgNPs or AgGO were tested for
their antibacterial activity against Escherichia coli and Staphylococcus aureus. The antibacterial results indicated that
the silver nanomaterial contained chitosan beads could effectively inhibit the growth of both E. coli and S. aureus as
compared to the bare chitosan beads. The produced chitosan nanocomposite envisioned that can be potentially employed
for water disinfection purpose.

Matched MeSH terms: Polymers
Effects of microwave on drug-release responses of spray-dried alginate microspheres

Mardziah RE, Wong TW

Drug Dev Ind Pharm, 2010 Oct;36(10):1149-67.
PMID: 20380595 DOI: 10.3109/03639041003695063

Microspheres prepared from rigid guluronic acid- (MG) and flexible mannuronic acid-rich (MC) alginate will undergo different drug release changes with respect to the influence of microwave on the matrix. An in-depth understanding of their differences in drug release changes is attainable through investigating cross-linking agent-free alginate microspheres prepared by spray-drying technique.

Matched MeSH terms: Polymers
Smart electrical bi-layers lipopeptides: Novel peptidic chains like zigzag map esterified with phospho-glyceride as mono-layer moieties capable in forming a meso-sphere- envelop with scaffold- ability to cellular impurities

Saadi S, Saari N, Abdulkarim MS, Ghazali HM, Anwar F

J Control Release, 2018 03 28;274:93-101.
PMID: 29031897 DOI: 10.1016/j.jconrel.2017.10.011

Cell impurities are an emerging nucleating molecular barriers having the capability in disordering the metabolic chain reactions of proteolysis, glycolysis and lipolysis. Their massive effects induced by copolymer crystal growth in compaction with metal and mineral transients are extended as well as in damaging DNA and mRNA structure motif and other molecular assembly e.g. histones structure unites. Their polycrystalline packing modes, polydispersity and their tendency to surface and interface adhesion prompted us in structuring scaffold biomaterials enriched with biopeptides, layered by phospho-glycerides ester-forms. The interface tension of the formed map is flexible and dependent to the surface exposure and its collapse modes to the surrounding molecular ligands. Thus, the attempts in increasing surface exposure e.g. the viscoelastic of structured lipopeptides and types of formed network structures interplays an extra- conjugating biomolecules having a least cytotoxicity effects to cells constituents. Disulfides molecules are selected to be the key regulatory element in rejoining both lipidic and proteic moieties by disordering atoms status via chemical ionization using organic catalyst. The insertion of methionine based peptidic chain at the lateral surfaces of scaffold biomaterials enhances the electron-meta-static motions by raising a molecular disordering status at distinct regions of the map e.g. epimerization into a nonpolar side that helps the chemical conjunction of disulfide groups with the esterified phosphoglycerides mono-layers. These effects in turn are accomplished by the formation of meso-sphere nonpolar- vesicles. The oxidation of disulfide group would alter the ordering of initial molecules by raising a newly molecular disorders to the map with high polarity to surface regions. In the same time indicates a continuation in the crystallization growth factor via a low chemical lesions between the impurities and a supersaturation in the intra-atomic distances with maximum cross linking to the deformed ligand with scaffold biomaterials.

Matched MeSH terms: Polymers
Rapid ultrasound assisted emulsification micro-solid phase extraction based on molecularly imprinted polymer for HPLC-DAD determination of bisphenol A in aqueous matrices

Rozaini MNH, Yahaya N, Saad B, Kamaruzaman S, Hanapi NSM

Talanta, 2017 Aug 15;171:242-249.
PMID: 28551135 DOI: 10.1016/j.talanta.2017.05.006

Molecularly imprinted polymer (MIP) was employed as sorbent in ultrasound assisted emulsification molecularly imprinted polymer micro-solid phase extraction (USAE-MIP-µ-SPE) of bisphenol A (BPA) in water, beverages and the aqueous liquid in canned foods prior to high performance liquid chromatography-diode array detector (HPLC-DAD) analysis. Several effective variables, such as types of emulsification solvent and its volume, types of desorption solvent and its volume, salting out effect, pH of sample solution, mass of sorbent, extraction and desorption time, and sample volume, were optimized comprehensively. Under the optimized USAE-MIP-µ-SPE and HPLC-DAD conditions, the method demonstrated good linearity over the range of 0.5-700μgL-1with a coefficient determination of R2=0.9973, low limit of detection (0.07μgL-1), good analyte recoveries (82.2-118.9%) and acceptable RSDs (0.7-14.2%, n=3) with enrichment factor of 49. The method was applied to thirty samples of drinking water, mineral water, river water, lake water, as well as beverages and canned foods, the presence of BPA was identified in four samples. The proposed method showed good selectivity and reusability for extraction of BPA, and hence the USAE-MIP-µ-SPE is rapid, simple, cost effective and environmentally friendly.

Matched MeSH terms: Polymers
Investigating effect of proton-exchange membrane on new air-cathode single-chamber microbial fuel cell configuration for bioenergy recovery from Azorubine dye degradation

Kardi SN, Ibrahim N, Rashid NAA, Darzi GN

Environ Sci Pollut Res Int, 2019 Jul;26(21):21201-21215.
PMID: 31115820 DOI: 10.1007/s11356-019-05204-z

One of the biggest challenges of using single-chamber microbial fuel cells (MFCs) that utilize proton-exchange membrane (PEM) air cathode for bioenergy recovery from recalcitrant organic compounds present in wastewater is mainly attributed to their high internal resistance in the anodic chamber of the single microbial fuel cell (MFC) configurations. The high internal resistance is due to the small surface area of the anode and cathode electrodes following membrane biofouling and pH splitting conditions as well as substrate and oxygen crossover through the membrane pores by diffusion. To address this issue, the fabrication of new PEM air-cathode single-chamber MFC configuration was investigated with inner channel flow open assembled with double PEM air cathodes (two oxygen reduction activity zones) coupled with spiral-anode MFC (2MA-CsS-AMFC). The effect of various proton-exchange membranes (PEMs), including Nafion 117 (N-117), Nafion 115 (N-115), and Nafion 212 (N-212) with respective thicknesses of 183, 127, and 50.08 μ, was separately incorporated into carbon cloth as PEM air-cathode electrode to evaluate their influences on the performance of the 2MA-CsS-AMFC configuration operated in fed-batch mode, while Azorubine dye was selected as the recalcitrant organic compound. The fed-batch test results showed that the 2MA-CsS-AMFC configuration with PEM N-115 operated at Azorubine dye concentration of 300 mg L-1 produced the highest power density of 1022.5 mW m-2 and open-circuit voltage (OCV) of 1.20 V coupled with enhanced dye removal (4.77 mg L h-1) compared to 2MA-CsS-AMFCs with PEMs N-117 and N-212 and those in previously published data. Interestingly, PEM 115 showed remarkable reduction in biofouling and pH splitting. Apart from that, mass transfer coefficient of PEM N-117 was the most permeable to oxygen (KO = 1.72 × 10-4 cm s-1) and PEM N-212 was the most permeable membrane to Azorubine (KA = 7.52 × 10-8 cm s-1), while PEM N-115 was the least permeable to both oxygen (KO = 1.54 × 10-4) and Azorubine (KA = 7.70 × 10-10). The results demonstrated that the 2MA-CsS-AMFC could be promising configuration for bioenergy recovery from wastewater treatment under various PEMs, while application of PEM N-115 produced the best performance compared to PEMs N-212 and N-117 and those in previous studies of membrane/membrane-less air-cathode single-chamber MFCs that consumed dye wastewater.

Matched MeSH terms: Fluorocarbon Polymers
Fulltext Kolaviron Protects the Prefrontal Cortex and Hippocampus against Histomorphological and Neurobehavioural Changes in Cuprizone Model of Multiple Sclerosis

Omotoso GO, Olajide OJ, Gbadamosi IT, Rasheed MA, Izuogu CT

Malays J Med Sci, 2018 Mar;25(2):50-63.
PMID: 30918455 DOI: 10.21315/mjms2018.25.2.6

Background: This study explored the efficacy of kolaviron-a biflavonoid complex isolated from the seeds of Garcinia kola-in protecting against cuprizone (CPZ)-induced demyelination in both the prefrontal cortex and the hippocampus of Wistar rats.
Methodology: Thirty rats were treated to receive 0.5 mL phosphate-buffered saline (group A, control), 0.5 mL corn oil (group B), 0.2% CPZ (group C), for 6 weeks, 0.2% CPZ for 3 weeks and then 200 mg/kg of Kv for 3 weeks (group D), or 200 mg/kg of Kv for 3 weeks followed by 0.2% CPZ for 3 weeks (group E). Rats were assessed for exploratory functions and anxiety-like behaviour before being euthanised and perfused transcardially with 4% paraformaldehyde. Prefrontal and hippocampal thin sections were stained in hematoxylin and eosin and cresyl fast violet stains.
Results: CPZ-induced demyelination resulted in behavioural impairment as seen by reduced exploratory activities, rearing behaviour, stretch attend posture, center square entry, and anxiogenic characteristics. Degenerative changes including pyknosis, karyorrhexis, neuronal hypertrophy, and reduced Nissl integrity were also seen. Animals treated with Kv showed significant improvement in behavioural outcomes and a comparatively normal cytoarchitectural profile.
Conclusion: Kv provides protective roles against CPZ-induced neurotoxicity through prevention of ribosomal protein degradation.

Matched MeSH terms: Polymers
The effect of filler content and processing variables on dimensional accuracy of experimental composite inlay material

Razak AA, Harrison A

J Prosthet Dent, 1997 Apr;77(4):353-8.
PMID: 9104710

Dimensional accuracy of a composite inlay restoration is important to ensure an accurate fit and to minimize cementation stresses.

Matched MeSH terms: Polymers/chemistry
Anti-inflammatory and analgesic activity of novel oral aspirin-loaded nanoemulsion and nano multiple emulsion formulations generated using ultrasound cavitation

Tang SY, Sivakumar M, Ng AM, Shridharan P

Int J Pharm, 2012 Jul 1;430(1-2):299-306.
PMID: 22503988 DOI: 10.1016/j.ijpharm.2012.03.055

The present study investigated the anti-inflammatory and analgesic activities of novel aspirin oil-in-water (O/W) nanoemulsion and water-in-oil-in-water (W/O/W) nano multiple emulsion formulations generated using ultrasound cavitation techniques. The anti-inflammatory activities of nanoemulsion and nano multiple emulsion were determined using the λ-carrageenan-induced paw edema model. The analgesic activities of both nanoformulations were determined using acetic acid-induced writhing response and hot plate assay. For comparison, the effect of pretreatment with blank nanoemulsion and reference aspirin suspension were also studied for their anti-inflammatory and antinociceptive activities. The results showed that oral administration of nanoemulsion and nano multiple emulsion containing aspirin (60 mg/kg) significantly reduced paw edema induced by λ-carrageenan injection. Both nanoformulations decreased the number of abdominal constriction in acetic acid-induced writhing model. Pretreatment with nanoformulations led to a significant increase in reaction time in hot plate assay. Nanoemulsion demonstrated an enhanced anti-inflammatory and analgesic effects compared to reference suspension while nano multiple emulsion exhibited a mild inhibitory effects in the three experimental animal model tests. The results obtained for nano multiple emulsion were relatively lower than reference. However, administration of blank nanoemulsion did not alter the nociceptive response significantly though it showed slight anti-inflammatory effect. These experimental studies suggest that nanoemulsion and nano multiple emulsion produced a pronounced anti-inflammatory and analgesic effects in rats and may be candidates as new nanocarriers for pharmacological NSAIDs in the treatment of inflammatory disorders and alleviating pains.

Matched MeSH terms: Polymers/chemistry*
Preparation, characterization, and optimization of asenapine maleate mucoadhesive nanoemulsion using Box-Behnken design: In vitro and in vivo studies for brain targeting

Kumbhar SA, Kokare CR, Shrivastava B, Gorain B, Choudhury H

Int J Pharm, 2020 Aug 30;586:119499.
PMID: 32505580 DOI: 10.1016/j.ijpharm.2020.119499

The tight junctions between capillary endothelial cells of the blood-brain barrier (BBB) restricts the entry of therapeutics into the brain. Potential of the intranasal delivery tool has been explored in administering the therapeutics directly to the brain, thus bypassing BBB. The objective of this study was to develop and optimize an intranasal mucoadhesive nanoemulsion (MNE) of asenapine maleate (ASP) in order to enhance the nasomucosal adhesion and direct brain targetability for improved efficacy and safety. Box-Behnken statistical design was used to recognize the crucial formulation variables influencing droplet size, size distribution and surface charge of ASP-NE. ASP-MNE was obtained by incorporating GRAS mucoadhesive polymer, Carbopol 971 in the optimized NE. Optimized ASP-MNE displayed spherical morphology with a droplet size of 21.2 ± 0.15 nm and 0.355 polydispersity index. Improved ex-vivo permeation was observed in ASP-NE and ASP-MNE, compared to the ASP-solution. Finally, the optimized formulation was found to be safe in ex-vivo ciliotoxicity study on sheep nasal mucosa. The single-dose pharmacokinetic study in male Wistar rats revealed a significant increase in concentration of ASP in the brain upon intranasal administration of ASP-MNE, with a maximum of 284.33 ± 5.5 ng/mL. The time required to reach maximum brain concentration (1 h) was reduced compared to intravenous administration of ASP-NE (3 h). Furthermore, it has been established during the course of present study, that the brain targeting capability of ASP via intranasal administration had enhanced drug-targeting efficiency and drug-targeting potential. In the animal behavioral studies, no extrapyramidal symptoms were observed after intranasal administration of ASP-MNE, while good locomotor activity and hind-limb retraction test established its antipsychotic activity in treated animals. Thus, it can be concluded that the developed intranasal ASP-MNE could be used as an effective and safe tool for brain targeting of ASP in the treatment of psychotic disorders.

Matched MeSH terms: Polymers/chemistry
Novel functional antimicrobial and biocompatible arabinoxylan/guar gum hydrogel for skin wound dressing applications

Khan MUA, Raza MA, Razak SIA, Abdul Kadir MR, Haider A, Shah SA, et al.

J Tissue Eng Regen Med, 2020 10;14(10):1488-1501.
PMID: 32761978 DOI: 10.1002/term.3115

It is a challenging task to develop active biomacromolecular wound dressing materials that are biocompatible and possesses antibacterial properties against the bacterial strains that cause severe skin disease. This work is focused on the preparation of a biocompatible and degradable hydrogel for wound dressing application using arabinoxylan (ARX) and guar gum (GG) natural polymers. Fourier transform infrared spectroscopy (FT-IR) confirmed that both ARX and GG interacted well with each other, and their interactions further increased with the addition of crosslinker tetraethyl orthosilicate. Scanning electron microscope (SEM) micrographs showed uniform porous morphologies of the hydrogels. The porous morphologies and uniform interconnected pores are attributed to the increased crosslinking of the hydrogel. Elastic modulus, tensile strength, and fracture strain of the hydrogels significantly improved (from ATG-1 to ATG-4) with crosslinking. Degradability tests showed that hydrogels lost maximum weight in 7 days. All the samples showed variation in swelling with pH. Maximum swelling was observed at pH 7. The hydrogel samples showed good antibacterial activity against Pseudomonas aeruginosa (Gram-negative) and Staphylococcus aureus (Gram-positive) in PBS, good drug release profile (92% drug release), and nontoxic cellular behavior. The cells not only retained their cylindrical morphologies onto the hydrogel but were also performing their normal activities. It is, therefore, believed that as-developed hydrogel could be a potential material for wound dressing application.

Matched MeSH terms: Polymers/chemistry
Fulltext Exceedingly Higher co-loading of Curcumin and Paclitaxel onto Polymer-functionalized Reduced Graphene Oxide for Highly Potent Synergistic Anticancer Treatment

Muthoosamy K, Abubakar IB, Bai RG, Loh HS, Manickam S

Sci Rep, 2016 Sep 06;6:32808.
PMID: 27597657 DOI: 10.1038/srep32808

Metastasis of lung carcinoma to breast and vice versa accounts for one of the vast majority of cancer deaths. Synergistic treatments are proven to be the effective method to inhibit malignant cell proliferation. It is highly advantageous to use the minimum amount of a potent toxic drug, such as paclitaxel (Ptx) in ng/ml together with a natural and safe anticancer drug, curcumin (Cur) to reduce the systemic toxicity. However, both Cur and Ptx suffer from poor bioavailability. Herein, a drug delivery cargo was engineered by functionalizing reduced graphene oxide (G) with an amphiphilic polymer, PF-127 (P) by hydrophobic assembly. The drugs were loaded via pi-pi interactions, resulting in a nano-sized GP-Cur-Ptx of 140 nm. A remarkably high Cur loading of 678 wt.% was achieved, the highest thus far compared to any other Cur nanoformulations. Based on cell proliferation assay, GP-Cur-Ptx is a synergistic treatment (CI

Matched MeSH terms: Polymers/chemistry*
Fulltext Antimycobacterial susceptibility evaluation of rifampicin and isoniazid benz-hydrazone in biodegradable polymeric nanoparticles against Mycobacterium tuberculosis H37Rv strain

Hakkimane SS, Shenoy VP, Gaonkar SL, Bairy I, Guru BR

Int J Nanomedicine, 2018;13:4303-4318.
PMID: 30087562 DOI: 10.2147/IJN.S163925

INTRODUCTION: Tuberculosis (TB) is the single largest infectious disease which requires a prolonged treatment regime with multiple drugs. The present treatment for TB includes frequent administration of a combination of four drugs for a duration of 6 months. This leads to patient's noncompliance, in addition to developing drug-resistant strains which makes treatment more difficult. The formulation of drugs with biodegradable polymeric nanoparticles (NPs) promises to overcome this problem.
MATERIALS AND METHODS: In this study, we focus on two important drugs used for TB treatment - rifampicin (RIF) and isoniazid (INH) - and report a detailed study of RIF-loaded poly lactic-co-glycolic acid (PLGA) NPs and INH modified as INH benz-hydrazone (IH2) which gives the same therapeutic effect as INH but is more stable and enhances the drug loading in PLGA NPs by 15-fold compared to INH. The optimized formulation was characterized using particle size analyzer, scanning electron microscopy and transmission electron microscopy. The drug release from NPs and stability of drug were tested in different pH conditions.
RESULTS: It was found that RIF and IH2 loaded in NPs release in a slow and sustained manner over a period of 1 month and they are more stable in NPs formulation compared to the free form. RIF- and IH2-loaded NPs were tested for antimicrobial susceptibility against Mycobacterium tuberculosis H37Rv strain. RIF loaded in PLGA NPs consistently inhibited the growth at 70% of the minimum inhibitory concentration (MIC) of pure RIF (MIC level 1 µg/mL), and pure IH2 and IH2-loaded NPs showed inhibition at MIC equivalent to the MIC of INH (0.1 µg/mL).
CONCLUSION: These results show that NP formulations will improve the efficacy of drug delivery for TB treatment.

Matched MeSH terms: Polymers/chemistry*
Development of a synthetic bone scaffold using porous hydroxyapatite for bone repair

Mustaffa R, Besar I, Andanastuti M

Med J Malaysia, 2008 Jul;63 Suppl A:95-6.
PMID: 19025001

In this study, porous hydroxyapatite (HA) samples were fabricated via sponge techniques with the aid of sago as part of the binder mixture. Development processes for the production of porous bone graft substitutes are studied using polyurethane sponge. To obtain the optimum amount of binder for successful fabrication of porous HA were done. Initially, porous HA powder was synthesized using calcium hydroxide and orthorphosphoric acid. Meanwhile, sago was mixed with PVA in a certain ratio to be used as binder for preparing the porous HA. After a series of investigative tests were conducted to characterize the sintered samples, the use of the sago and polymeric mixture was found to successfully aid the fabrication of porous HA samples. In this investigation, comparison of physical and mechanical characteristics between samples prepared using difference techniques was made.

Matched MeSH terms: Polymers
Validation of thermally assisted hydrolysis and methylation-gas chromatography for rapid and direct compositional analysis of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) in whole bacterial cells

Baidurah S, Murugan P, Joyyi L, Fukuda J, Yamada M, Sudesh K, et al.

J Chromatogr A, 2016 Nov 04;1471:186-191.
PMID: 27769532 DOI: 10.1016/j.chroma.2016.10.019

Thermally assisted hydrolysis and methylation-gas chromatography (THM-GC) in the presence of an organic alkali was validated for the compositional analysis of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [P(3HB-co-3HHx)] accumulated in whole bacterial cells. Recombinant Cupriavidus necator Re2058/pCB113 was grown in a batch fermentation with different concentration of palm oil and fructose in order to control the molar fraction of 3HHx in P(3HB-co-3HHx) produced in the cells. Trace amounts (30μg) of freeze-dried cells were directly subjected to THM-GC in the presence of tetramethylammonium hydroxide (TMAH) at 400°C. The obtained chromatograms clearly showed nine characteristic peaks, attributed to the THM products from 3HB and 3HHx units in the polymer chains, without any appreciable interference by the bacterial matrix components. Based on these peak intensities, the copolymer compositions were determined rapidly without using any cumbersome and lengthy sample pretreatment as in conventional GC method. Moreover, the compositions thus obtained were strongly correlated with those by NMR and conventional GC involving solvent extraction.

Matched MeSH terms: Polymers
Fulltext Polymer-free drug-coated coronary stents in patients at high bleeding risk

Urban P, Meredith IT, Abizaid A, Pocock SJ, Carrié D, Naber C, et al.

N Engl J Med, 2015 Nov 19;373(21):2038-47.
PMID: 26466021 DOI: 10.1056/NEJMoa1503943

BACKGROUND: Patients at high risk for bleeding who undergo percutaneous coronary intervention (PCI) often receive bare-metal stents followed by 1 month of dual antiplatelet therapy. We studied a polymer-free and carrier-free drug-coated stent that transfers umirolimus (also known as biolimus A9), a highly lipophilic sirolimus analogue, into the vessel wall over a period of 1 month.
METHODS: In a randomized, double-blind trial, we compared the drug-coated stent with a very similar bare-metal stent in patients with a high risk of bleeding who underwent PCI. All patients received 1 month of dual antiplatelet therapy. The primary safety end point, tested for both noninferiority and superiority, was a composite of cardiac death, myocardial infarction, or stent thrombosis. The primary efficacy end point was clinically driven target-lesion revascularization.
RESULTS: We enrolled 2466 patients. At 390 days, the primary safety end point had occurred in 112 patients (9.4%) in the drug-coated-stent group and in 154 patients (12.9%) in the bare-metal-stent group (risk difference, -3.6 percentage points; 95% confidence interval [CI], -6.1 to -1.0; hazard ratio, 0.71; 95% CI, 0.56 to 0.91; P<0.001 for noninferiority and P=0.005 for superiority). During the same time period, clinically driven target-lesion revascularization was needed in 59 patients (5.1%) in the drug-coated-stent group and in 113 patients (9.8%) in the bare-metal-stent group (risk difference, -4.8 percentage points; 95% CI, -6.9 to -2.6; hazard ratio, 0.50; 95% CI, 0.37 to 0.69; P<0.001).
CONCLUSIONS: Among patients at high risk for bleeding who underwent PCI, a polymer-free umirolimus-coated stent was superior to a bare-metal stent with respect to the primary safety and efficacy end points when used with a 1-month course of dual antiplatelet therapy. (Funded by Biosensors Europe; LEADERS FREE ClinicalTrials.gov number, NCT01623180.).

Matched MeSH terms: Polymers

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