No abstract

In order to investigate the effects of surface roughness, surface wettability and swelling on protein adsorption, polyurethane films were prepared from castor oil (CO) and poly(ethylene glycol)‐3000 (PEG) using one‐shot bulk polymerization. Hexamethylene diisocyanate and 1,4‐butanediol were used as isocyanate and chain extender, respectively. The hydrophilicity of the polyurethane films was adjusted by varying the ratio of CO to PEG. The surface of the polyurethane films was treated using plasma polymerization in the presence of acrylic acid vapour. Therefore, the polyurethane films could be obtained with the same hydrophilicity but with different roughness. The hydrophilicity of untreated and treated polymer films was examined using contact angle measurements. The surface topology of the polymer films was investigated using scanning electron microscopy and atomic force microscopy. Adsorption of bovine serum albumin and bovine serum fibrinogen on treated and untreated polymer films was determined and the performance of the films was compared. After evaluation of all results it is found that surface roughness and swelling are as important as hydrophilicity for protein adsorption in the case of CO/PEG‐based polyurethanes. © 2012 Society of Chemical Industry

This study presents the design of novel hydrogel films, based on low-methoxyl (LM) pectin and NaA-or ZnA-zeolite particles, to serve as wound dressing materials with controlled drug delivery properties. We studied the effects of the preparation method of hydrogels, the amounts of crosslinker, drug and zeolite, and the type of cation in zeolites on the drug release mechanisms from the hydrogels. Ionic strengths of both film and external medium dictated the drug release behavior of the films, while the other parameters also played essential roles. NaAzeolite hydrogels prepared using membrane diffusion controlled system, could reach a drug release ratio of 86% within 5 h. The drug-free hydrogels displayed no cytotoxicity while supporting cell proliferation and migration. Our cost-effective LM pectin-zeolite hydrogels promise to be effective wound dressing materials with controlled drug delivery ability, transparency, good swelling properties, ability to hold fluids, good oxygen transmission rate, and biocompatibility.Pectin is a water soluble polysaccharide mostly extracted from citrus peels. It is a byproduct or waste product of fruit juice industry; therefore, it is easily available and cheap. It is mainly composed of linear chains of galacturonic acid residues. Pectin is referred to as low-methoxyl pectin (LM-pectin) in case the degree of esterification of the carboxylic acid groups is <50%. LM pectin forms three-dimensional (3D) network gels of Ca 2+ ion-bridged dimers to induce an "egg box shell" structure, 4 which makes it an Additional Supporting Information may be found in the online version of this article.

Fatty acid-based polyurethane films were prepared for use as potential wound dressing material. The polymerization reaction was carried out with or without catalyst. Polymer films were prepared by casting-evaporation technique with or without crosslink-catalyst. The film prepared from uncatalyzed reaction product with crosslink-catalyst gave slightly higher crosslink density. The mechanical tests showed that, the increase in the tensile strength and decrease in the elongation at break is due to the increase in the degree of crosslinking. All films were flexible, and resisted to acid solution. The films prepared without crosslink-catalyst were more hydrophilic, absorbed more water. The highest permeability values were generally obtained for the films prepared without crosslink catalyst. Both the direct contact method and the MMT test were applied for determination of cytotoxicity of polymer films and the polyurethane film prepared from uncatalyzed reaction product without crosslink-catalyst showed better biocompatibility property, closest to the commercial product, Opsite Ò .

ABSTRACT:As an alternative to petroleum-based polyol, hydroxyl containing material was prepared from linseed oil for polyurethane synthesis. Hexamethylene di-isocyanate (HMDI) and/or 4, 4 0 -methylene diphenyl di-isocyanate (MDI) were used as isocyanate source. The polymerization reaction was carried out without catalyst. Polymer films were prepared by casting-evaporation technique. The MDI/ HMDI-based polyurethane and its films had higher T g and better thermal property than that of the HMDI-based one because of the existence of benzene ring in the polymer chain. Static water contact angle was determined to be 74 and 77.5for HMDI and MDI/HMDI-based films, respectively. Water adsorption was found to be around 2.6-3.6% for both films. In vitro degradation of polyurethanes in phosphate buffered saline at 37 C was investigated by gravimetric method. Fourier transform infrared spectroscopy and scanning electron microscopy were used for confirmation of degradation on the polymer surface. The degradation rate of the HMDI-based polyurethane film was found higher than that of the MDI/HMDI-based film. Both the direct contact method and the MMT test were applied for determination of cytotoxicity of polymer films, and the polyurethane films investigated here was not cytotoxic. Silver-containing films were prepared using Biocera A V R as filler and were screened for their antibacterial performance against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and/or Bacillus subtilis. The films prepared with and without Biocera A V R exhibited antibacterial activity.