Synthesis and characterization of novel comb-type amphiphilic graft copolymers containing polypropylene and polyethylene glycol

Synthesized of a novel xanthate functionalized polypropylene as adsorbent for dispersive solid phase microextraction of caffeine using orbital shaker in mixed beverage matrices

A newly synthesized xanthate functionalized chlorinated polypropylene (PP-Xa) was used as adsorbent for the orbital shaker based on dispersive solid phase microextraction (OS-DSPME) of caffein from several tea, coffee, energy drink, coca-cola and chocolate samples using UV-vis. spectrophotometer. Synthesized PP-Xa was characterized using Fourier Transform Infrared spectroscopy (FTIR-ATR) and nuclear magnetic resonance spectroscopy (¹H NMR). Various parameters like pH, PP-Xa amount, extraction time, type of eluent and its volume were optimized. Linear range, detection limit (LOD), limit of quantification (LOQ), relative standard deviation (RSD), recovery values, and enrichment factor (EF) were found 90-1000 μgL^-1, 27.3 µg L^-1, 90 µg L^-1, 1.9-2.6%, 98 ± 2%, and 167, respectively. Adsorption capacity of PP-Xa was found 271.9 mg g^-1. Standard addition and reference method were used for confirm the accuracy of present method.

Recent advances in the self-assembly of sparsely grafted amphiphilic copolymers in aqueous solution

This review describes the self-assembly of sparsely grafted amphiphilic copolymers and highlights the effects of structural factors and solvents on their self-assembly behaviour.

Gold and Cobalt Oxide Nanoparticles Modified Poly-Propylene Poly-Ethylene Glycol Membranes in Poly (ε-Caprolactone) Conduits Enhance Nerve Regeneration in the Sciatic Nerve of Healthy Rats

Reconstruction of nerve defects is a clinical challenge. Autologous nerve grafts as the gold standard treatment may result in an incomplete restoration of extremity function. Biosynthetic nerve conduits are studied widely, but still have limitations. Here, we reconstructed a 10 mm sciatic nerve defect in healthy rats and analyzed nerve regeneration in poly (ε-caprolactone) (PCL) conduits longitudinally divided by gold (Au) and gold-cobalt oxide (AuCoO) nanoparticles embedded in poly-propylene poly-ethylene glycol (PPEG) membranes (AuPPEG or AuCoOPPEG) and compared it with unmodified PPEG-membrane and hollow PCL conduits. After 21 days, we detected significantly better axonal outgrowth, together with higher numbers of activated Schwann cells (ATF3-labelled) and higher HSP27 expression, in reconstructed sciatic nerve and in corresponding dorsal root ganglia (DRG) in the AuPPEG and AuCoOPPEG groups; whereas the number of apoptotic Schwann cells (cleaved caspase 3-labelled) was significantly lower. Furthermore, numbers of activated and apoptotic Schwann cells in the regenerative matrix correlated with axonal outgrowth, whereas HSP27 expression in the regenerative matrix and in DRGs did not show any correlation with axonal outgrowth. We conclude that gold and cobalt-oxide nanoparticle modified membranes in conduits improve axonal outgrowth and increase the regenerative performance of conduits after nerve reconstruction.

Development of sensitive and accurate solid-phase microextraction procedure for preconcentration of As(III) ions in real samples

We synthesized the poly(methyl methacrylate-co-2-aminoethyl methacrylate (PMaema) amphiphilic copolymer in a form of solid phase adsorbent. Then it was used for separation, preconcentration and determination of trace amount of As(III) ions from foods and waters with hydride generation atomic absorption spectrometry. The PMaema was characterized by fourier transform infrared spectrometer and nuclear magnetic resonance spectrometer. The adsorption of As(III) to the PMaema was also supported using computational chemistry studies. The experimental parameters (pH, PMaema amount, adsorption time and ethanol volume) were optimized using a three-level Box-Behnken design with four experimental factors. We observed linear calibration curve for the PMaema amount in the 10-500 ng L-1 range (R2 = 0.9956). Limit of detection, preconcentration factor and sorbent capacity of PMaema were equal to 3.3 ng L-1, 100 and 75.8 mg g-1, respectively. The average recoveries (spiked at 50 ng L-1) changes in the range of 91.5-98.6% with acceptable relative standard deviation less than 4.3%. After validation studies, the method was successfully applied for separation, preconcentration and determination of trace amount of As(III) from foods and waters.

Synthesis of a novel tannic acid-functionalized polypropylene as antioxidant active-packaging materials

This work focuses on the synthesis of novel tannin-functionalized polypropylene copolymers that are designed to inhibit the oxidation of vegetable oils for potential use as packaging materials. An empty glass Petri dish (control), a chlorinated polypropylene-coated glass Petri dish (control) and a series of the tannin-functionalized polypropylene coated glass Petri dishes overlaid with linseed oil were exposed to air and additional white light. Oligomerization of the oxidized linseed oil was assessed by measuring the flow properties of the exposed oil using a viscometer. The antioxidant effect of the tannic acid grafted polypropylene copolymers (PP-Tann) retarded oligomerization of the linseed oil. The molar mass of the linoleic acid overlaid onto the PP-Tann films was the lowest among the tested samples after each time period indicating that tannin-grafted polypropylene may be a promising packaging material for vegetable oils.

Hydrophilic modification of polyvinyl chloride with polyacrylic acid using ATRP

The aim of this paper was the synthesis of amphiphilic copolymers by employing an atom transfer radical polymerization (ATRP), control polymerization “grafting from” method, initiated both on the surface of an iodinated polyvinyl chloride (PVC–I) membrane and in solution. The iodination of PVC was performed through a Conant-Finkelstein reaction that afforded a 30% molar transformation. Using the contact angle measurements, we highlighted the higher degree of grafting polyacrylic acid (PAA) in the case of solution polymerization, the polar fraction increasing significantly. The micromembrane obtained by surface grafting has pores with a homogenous distribution, which contain –COOH functional groups and with a pore size that decreased about 10 times compared to the initial membrane. The TGA analysis highlighted the thermal resistance changes that the polymers registered.

Amphiphilic copolymers were synthesized through a “grafting from” technique using an atom transfer radical polymerization (ATRP) initiated from the surface of an iodinated polyvinyl chloride (PVC-I) membrane and in solution.

A review of emerging bone tissue engineering via PEG conjugated biodegradable amphiphilic copolymers

Defects in bones can be caused by a plethora of reasons, such as trauma or illness, and in many cases, it poses challenges to the current treatment approaches for bone repair. With increasing demand of bone bioengineering in tissue transplant, there is a need to source for sustainable solutions to induce bone regeneration. Polymeric biomaterials have been identified as a promising approach due to its excellent biocompatibility and controllable biodegradability. Specifically, poly(ethylene glycol) (PEG) is one of the most commonly investigated polymer for use in bio-related application due to its bioinertness and versatility. Furthermore, the hydrophilic nature enables it to be incorporated with hydrophobic but biodegradable polymers like, polylactide (PLA) and polycaprolactone (PCL), to create an amphiphilic polymer. This article reviews the recent synthetic strategies available for the construction of PEG conjugated polymeric system, analysis of PEG influence on the material properties, and provides an overview of its application in bone engineering.

Characterizing the structure and properties of dry and wet polyethylene glycol using multi-scale simulations

Multi-scale simulations to study the structure and material properties of PEG in dry and wet conditions.

Tunable amphiphilic graft copolymers bearing fatty chains and polyoxazoline: synthesis and self-assembly behavior in solution

Synthesis and self-assembly behavior in solution of tunable copolymers with amphiphilic grafts based on fatty chain polymethacrylate and polyoxazoline.

Effects of polymer-based, silver nanoparticle-coated silicone splints on the nasal mucosa of rats

Infection is a serious complication after nasal packing that otolaryngologists seek to avoid. The aim of this study is to investigate the use of silver (Ag) nanoparticle, which serves as antimicrobial agents, with nasal tampons. The study design is an experimental animal model and the setting is tertiary referral center. Twenty-four rats were randomized into the following four groups: (1) control group (n = 6); (2) silicone nasal splint (SNS) group (n  =  6); (3) polypropylene-grafted polyethylene glycol (PP-g-PEG) amphiphilic graft copolymer-coated SNS group (n  =  6); and (4) Ag nanoparticle-embedded PP-g-PEG (Ag-PP-g-PEG) amphiphilic graft copolymer-coated SNS group (n  =  6). These tampons were applied to rats for 48 h, after which they were removed in a sterile manner, and the rats were sacrificed. The nasal septa of the rats were excised, and assessments of tissue changes in the nasal mucosa were compared among the groups. The removed tampons were microbiologically examined, and quantitative analyses were made. When the groups were compared microbiologically, there were no significant differences in bacterial colonization rates of coagulase-negative Staphylococcus spp. among the three groups (p = 0.519), but there was a statistically significant difference among bacterial colonization rates of Heamophilus parainfluenzae and Corynebacterium spp. (p = 0.018, p = 0.004). We found that H. parainfluenzae grew less robustly in the Ag-PP-g-PEG than the PP-g-PEG group (p = 0.017). However, we found no significant difference between the Ag-PP-g-PEG and SNS groups, or between the SNS and PP-g-PEG groups. The growth of Corynebacterium spp. did not differ significantly between the Ag-PP-g-PEG and SNS groups (p = 1.000). When Group 4 was compared with Group 2, the former showed less inflammation. Compared with other tampons, Ag-PP-g-PEG amphiphilic graft copolymer-coated silicone nasal tampons caused less microbiological colonization and inflammation. Therefore, the use of these tampons may prevent secondary infections and reduce the risk of developing complications by minimizing tissue damage.

Development and operation of gold and cobalt oxide nanoparticles containing polypropylene based enzymatic fuel cell for renewable fuels

Newly synthesized gold and cobalt oxide nanoparticle embedded Polypropylene-g-Polyethylene glycol was used for a compartment-less enzymatic fuel cell. Glucose oxidase and bilirubin oxidase were selected as anodic and cathodic enzymes, respectively. Electrode fabrication and EFC operation parameters were optimized to achieve high power output. Maximum power density of 23.5 µW cm(-2) was generated at a cell voltage of +560 mV vs Ag/AgCl, in 100mM PBS pH 7.4 with the addition of 20mM of synthetic glucose solution. 20 µg of polymer amount with 185 µg of glucose oxidase and 356 µg of bilirubin oxidase was sufficient to get maximum performance. The working electrodes could harvest glucose, produced during photosynthesis reaction of Carpobrotus Acinaciformis plant, and readily found in real domestic wastewater of Zonguldak City in Turkey.

Chitosan/Carboxymethylcellulose/Ionic Liquid/Ag(0) Nanoparticles Form a Membrane with Antimicrobial Activity

Silver metal nanoparticles were immobilized in chitosan/carboxymethylcellulose/BMI.BF4(1-n-butyl-3-methylimidazolium tetrafluoroborate ionic liquid) (CS/CMC/IL) to form polymeric membrane with 20 μm thickness. The CS/CMC/IL polymeric membrane was prepared using a simple solution blending method. Irregularly shaped Ag(0) nanoparticles with monomodal size distributions of8.0±0.4 nm Ag(0) were immobilized in the membrane. The presence of small Ag(0) nanoparticles induced an augmentation in the CS/CMC/IL film surface areas. The CS/CMC/IL membrane containing Ag(0) showed increase antimicrobial activity the Ag(0) concentration increased up to saturation at 10 mg. CS/CMC/IL membrane that contains Ag(0) nanoparticles has enhanced durability of the membrane and exhibited stronger antimicrobial activity againstEscherichia coliandStaphylococcus aureus.

The efficacy of silver-embedded polypropylene-grafted polyethylene glycol-coated ventricular catheters on prevention of shunt catheter infection in rats

PURPOSE

Catheter-related infection is a major complication of ventriculoperitoneal shunt in children. The aim of this study is to determine inflammatory response and the efficacy of polypropylene-grafted polyethylene glycol (PP-g-PEG) copolymer and silver nanoparticle-embedded PP-g-PEG (Ag-PP-g-PEG) polymer-coated ventricular catheters on the prevention of catheter-related infections on a new experimental model of ventriculoperitoneal shunt in rats.

METHODS

Thirty six Wistar albino rats were divided into six groups: group 1, unprocessed sterile silicone catheter-embedded group; group 2, sterile PP-g-PEG-coated catheter group; group 3, sterile Ag-PP-g-PEG-coated catheter group; group 4, infected unprocessed catheter group; group 5, infected PP-g-PEG-coated catheter group; and group 6, infected Ag-PP-g-PEG-coated catheter group, respectively. In all groups, 1-cm piece of designated catheters were placed into the cisterna magna. In groups 4, 5, and 6, all rats were infected with 0.2 mL of 10 × 10(6) colony forming units (CFU)/mL Staphylococcus epidermidis colonies before the catheters were placed. Thirty days after implantation, bacterial colonization in cerebrospinal fluid and on catheter pieces with inflammatory reaction in the brain parenchyma was analyzed quantitatively.

RESULTS

Sterile and infected Ag-PP-g-PEG-covered groups revealed significantly lower bacteria colony count on the catheter surface (ANOVA, 0 ± 0, p < 0.001; 1.08 ± 0.18, p < 0.05, respectively). There was moderate inflammatory response in the parenchyma in group 4, but in groups 5 and 6, it was similar to that of the sterile group (ANOVA, 16.33 ± 3.02, p < 0.001; 4.00 ± 0.68, p < 0.001, respectively).

CONCLUSIONS

The PP-g-PEG, especially Ag-PP-g-PEG polymer-coated ventricular catheters are more effective in preventing the catheter-related infection and created the least inflammatory reaction in the periventricular parenchyma.

Soft tissue response to the presence of polypropylene-G-poly(ethylene glycol) comb-type graft copolymers containing gold nanoparticles

The aim of this study is to evaluate the soft tissue response of the pure and Au-embedded PPg-PEG. PP-g-PEG2000, PP-g-PEG4000, Au-PP-g-PEG2000, and AuPP-g-PEG4000 were obtained via chlorination of polypropylene and polyethylene glycol in the presence of a base with a “grafting onto” technique. Solvent cast films of these four copolymers with PP as a control group were embedded into five different rats. After 30 days of implantation, microscopic evaluation of inflammation and SEM analysis were done. PP had the most intense inflammatory reaction among the other polymers. PP-PEG block copolymers with high molecular weight and gold-nanoparticles-embedded ones revealed mild inflammatory reaction independently. SEM assessment revealed punched hole-like defects on the surface of all polymer samples except for PP. Graft copolymers with PEG, especially Au-attached ones, have favorable soft tissue response, and inflammatory reaction becomes milder as the number of PEG side chains increases.