Shape memory histocompatible and biodegradable sponges for subcutaneous defect filling and repair: greatly reducing surgical incision.

Reducing surgical incision for large area subcutaneous defect filling and repair is a great challenge in the biomedical field, especially for plastic surgery. In this study, a novel hydroxyethyl cellulose/soy protein isolate (HEC/SPI) composite sponge (EHSS) with a fluid responsive shape memory property was constructed, whose thickness could be controlled by hot-pressing conditions to reduce the required surgical incision greatly. Effects of the main factors such as pressure, temperature and hot-pressing cycles on the recovery degree of EHSS were investigated systematically.

Accelerated skin wound healing by soy protein isolate-modified hydroxypropyl chitosan composite films.

In this study, a series of hydroxypropyl chitosan (HPCS)/soy protein isolate (SPI) composite films (HCSFs) with different SPI contents were developed via crosslinking, solution casting, and evaporation process. Effects of the SPI content on the structure and physical properties of the HCSFs were characterized by Fourier transform infrared spectroscopy, X-ray diffraction patterns, scanning electron microscopy, swelling kinetics analysis, and mechanical testing. The HCSFs exhibited a lower swelling ratio with an increase in the SPI content.

Preparation of fungus-derived chitin nanocrystals and their dispersion stability evaluation in aqueous media.

The chitin nanocrystal is a promising nano-reinforcing agent, but the parasitic pathogens carried on crabs and shrimp shells as main sources limit its application in some fields. In this study, the ChNs which avoided possible safety risks were extracted from mushrooms via protein/mineral-purification and subsequent HCl-hydrolysis. Such fungus-derived ChNs presented an α-chitin crystalline structure with a length of 143±24nm and a diameter of 10±2nm.

Porous cellulose spheres: Preparation, modification and adsorption properties.

Porous cellulose spheres (PCS) were fabricated by precipitating the spheres from a cellulose ionic liquid solution, followed by freezing, solvent exchange, and drying. PCS had low crystallinity and a large surface area that facilitated modification with trisodium trimetaphosphate (STMP) to introduce phosphate ester groups into the porous structure of the heterogeneous system. The STMP-modified PCS (SPCS) were used to remove heavy metal ions from aqueous solution.

Epichlorohydrin-Cross-linked Hydroxyethyl Cellulose/Soy Protein Isolate Composite Films as Biocompatible and Biodegradable Implants for Tissue Engineering.

A series of epichlorohydrin-cross-linked hydroxyethyl cellulose/soy protein isolate composite films (EHSF) was fabricated from hydroxyethyl cellulose (HEC) and soy protein isolate (SPI) using a process involving blending, cross-linking, solution casting, and evaporation. The films were characterized with FTIR, solid-state (13)C NMR, UV-vis spectroscopy, and mechanical testing. The results indicated that cross-linking interactions occurred in the inter- and intramolecules of HEC and SPI during the fabrication process.

Reinforcement and nucleation of acetylated cellulose nanocrystals in foamed polyester composites.

The biodegradable foamed nanocomposites were developed from the reinforcement of surface acetylated cellulose nanocrystals (ACNC) as bionanofillers and the poly(butylene succinate) (PBS) as polymeric matrix. The surface modification of high-efficiency acetylation on the cellulose nanocrystals converted the hydrophilic hydroxyl groups to hydrophobic acetyl groups, which improved the compatibility between rigid nanoparticles and polyester matrix through the similar ester groups of two components. With the introduction of 5 wt% ACNC, the specific flexural strength (σ/ρf) and the specific flexural modulus (E/ρf) of the foamed composites significantly increased by 75.

Modification of porous starch for the adsorption of heavy metal ions from aqueous solution.

Porous starch xanthate (PSX) and porous starch citrate (PSC) were prepared in anticipation of the attached xanthate and carboxylate groups respectively forming chelation and electrostatic interactions with heavy metal ions in the subsequent adsorption process. The lead(II) ion was selected as the model metal and its adsorption by PSX and PSC was characterized. The adsorption capacity was highly dependent on the carbon disulfide/starch and citric acid/starch mole ratios used during preparation.

Fabrication and evaluation of physical properties and cytotoxicity of zein-based polyurethanes.

Polyurethane prepolymer (PUP) was first synthesized from polycaprolactone diol and isophorone diisocyanate; and then a series of zein-based polyurethane (ZEPU) sheets was fabricated from PUP and zein (ZE) using a hot press and moulding process without addition of other additives. Effects of ZE content (WZE) on the structure and properties of the resultant ZEPU sheets were investigated by Fourier transform infrared spectroscopy, scanning electron microscopy, dynamic mechanical analysis, tensile testing, and dissolubility testing in alcohol. The results indicated that cross-linking and grafting reactions occurred between ZE and PUP to form new polyurethane showing a higher thermal stability, flexibility, and alcohol-resistance than the neat ZE sheets.

Physiological effects of magnetic iron oxide nanoparticles towards watermelon.

Nanoparticles (NPs) have been exploited in a diverse range of products in the past decade or so. However, the biosafety/environmental impact or legislation pertaining to this newly created, highly functional composites containing NPs (otherwise called nanomaterials) is generally lagging behind their technological innovation. To advance the agenda in this area, our current primary interest is focused on using crops as model systems as they have very close relationship with us.

Fabrication and reduction-sensitive behavior of polyion complex nano-micelles based on PEG-conjugated polymer containing disulfide bonds as a potential carrier of anti-tumor paclitaxel.

This work is aimed at the development of a reduction-sensitive drug carrier for the delivery of the anti-cancer drug paclitaxel (PTX). N,N'-bis(acryloyl)cystamine (CBA) was reacted with ethanolamine (AEOL) via Michael addition to synthesize cationic poly(CBA-AEOL) (PCA) containing disulfide bonds. Subsequently, polycaprolactone (PCL) was grafted from PCA to form a novel reduction-sensitive copolymer (PCA-g-PCL).

Structure and mechanical properties of new biomass-based nanocomposite: castor oil-based polyurethane reinforced with acetylated cellulose nanocrystal.

New nanocomposites consisting of a castor oil-based polyurethane matrix filled with acetylated cellulose nanocrystals (ACNs) were developed. The ACN exhibited improved dispersion in tetrahydrofuran as a blending medium, and reduced polarity as compared with unmodified cellulose nanocrystals, resulting in a high loading level of 25 wt% in the nanocomposite. As the ACN loading-level increased from 0% to 25%, the tensile strength and Young's modulus of the nanocomposites increased from 2.

The composites based on plasticized starch and graphene oxide/reduced graphene oxide.

The graphite was oxidized to prepare graphene oxide (GO), and GO was reduced by glucose to obtain reduced graphene oxide (RGO) sheet. There were abundant and residual oxygen-containing groups on GO and RGO, respectively. Compared to graphite, the GO and RGO sheets appeared flat and transparent, and the aqueous suspensions followed the Lambert-Beer's law well.

Improvement in hemocompatibility of chitosan/soy protein composite membranes by heparinization.

Objective: To improve the hemocompatibility of chitosan/soy protein isolate composite membranes by heparinization.

Methods: Chitosan/soy protein isolate membranes (ChS-n, n=0, 10 and 30, corresponding to the soy protein isolate content in the membranes) and heparinized ChS-n membranes (HChS-n) were prepared by blending in dilute HAc/NaAc solution. The hemocompatibility of ChS-n and HChS-n membranes were comparatively evaluated by measuring surface heparin density, blood platelet adhesion, plasma recalcification time (PRT), thrombus formation and hemolysis assay.

Nanocomposites based on plasticized starch and rectorite clay: structure and properties.

Sodium rectorite clay (REC) was attached to cationic guar gum (CGG) using a cationic-exchange reaction to obtain CGG modified-REC (CREC). It was found that CGG appeared on the surface of REC's layered structure and represented about 30.1% wt.

Development of t(50) and its application to evaluate very-high-gravity ethanol fermentation.

A three-parameter logistic growth model was modified to monitor the glucose uptake profile of yeast during very-high-gravity (VHG) ethanol fermentation. The modified model was used to define t(50) as a quantifier to differentiate among various fermentation conditions. There are two types of t(50); t(50)(g) is the time required to convert 50% of the initial glucose, and t(50)(e) is the time required to produce half of the final ethanol.

Effect of polysaccharide nanocrystals on structure, properties, and drug release kinetics of alginate-based microspheres.

Polysaccharide nanocrystals, such as rod-like cellulose nanocrystals and chitin whiskers and platelet-like starch nanocrystals, were incorporated into alginate-based nanocomposite microspheres with the aim of enhancing mechanical strength and regulating drug release behavior. The structures and properties of the sols and the resultant nanocomposite microspheres were characterized by rheological testing, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The presence of polysaccharide nanocrystals increased the stability of the crosslinked network structure, and the nanocomposite microspheres consequently exhibited prominent sustained release profiles, as demonstrated by inhibited diffusion of theophylline.

Characterization of magnetic soluble starch-functionalized carbon nanotubes and its application for the adsorption of the dyes.

Soluble starch-functionalized multiwall carbon nanotube composites (MWCNT-starch) were prepared to improve the hydrophilicity and biocompatibility of MWCNTs. Characterization of the MWCNT-starch by Fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible (UV-vis) spectroscopy, X-ray diffraction (XRD), transmission electron microscope (TEM) and thermogravimetric analysis (TG), showed that the starch component (about 14.3 wt%) was covalently grafted onto the surface of MWCNT.

Chitosan colloidal suspension composed of mechanically disassembled nanofibers.

Joint treatments of wet-grinding and high-pressure homogenization effectively disassembled chitosan particles into nanofibers by breaking the bond interactions between the chitosan crystalline fibrils using only strong mechanical force. We demonstrated the size reduction of chitosan fibers and characterized the properties and structure of the obtained nanofibrils. Results showed that the obtained nanofibers had a diameter of about 50nm, which comprised small bundles of nanofibrils with a diameter of 1-5nm.

Biomimetic soy protein nanocomposites with calcium carbonate crystalline arrays for use as wood adhesive.

Despite the biodegradability, non-toxicity, and renewability, commercially available soy protein-based adhesives still have not been widely adopted by industry, partially due to their disappointing performances, i.e., low glue strength in the dry state and no glue strength in the wet state.

Starch composites reinforced by bamboo cellulosic crystals.

Using a method of combined HNO(3)-KClO(3) treatment and sulfuric acid hydrolysis, bamboo cellulose crystals (BCCs) were prepared and used to reinforce glycerol plasticized starch. The structure and morphology of BCCs were investigated using X-ray diffraction, electron microscopy, and solid-state (13)C NMR. Results showed that BCCs were of typical cellulose I structure, and the morphology was dependent on its concentration in the suspension.

In vitro bile acid binding and short-chain fatty acid profile of flax fiber and ethanol co-products.

Fibers from flaxseed and co-products from ethanol production could be potential sources of dietary fiber in human diet. In vitro fermentation and bile acid binding models were used to investigate the metabolic effects of lignaMax (Bioriginal Food and Science Corp., Saskatoon, SK, Canada) flax meal, spent flax meal, soluble flax gum, wheat insoluble fiber (WIF), and rye insoluble fiber (RIF).

Transitional properties of starch colloid with particle size reduction from micro- to nanometer.

High-pressure homogenization was used to disperse starch particles in water and reduce the size from micro- to nanometer. The resultant starch colloids were characterized by particle morphology, mean size, size distribution, and zeta potential. Starch slurries were transformed from a mixture containing sediment, dispersion, and sol, to gel as a result of reduction of the particle size from 3-6mum to 10-20nm under a pressure of 207MPa.

Microwave-vacuum drying of flax fiber for biocomposite production.

Flax fiber is one of the important bast fiber available in North America which has low density and good mechanical properties for reinforcing various polymers to develop industrial biocomposite. But the hydrophilic nature of the fiber leads to poor adhesion between the fiber and the polymer matrices which, in turn, leads to poor dimensional stability. To enhance the adhesion between polymer matrix and fiber, chemical treatments of the fiber are necessary.

Preparation, characterization, and in vitro and in vivo evaluation of cellulose/soy protein isolate composite sponges.

A series of cellulose/soy protein isolate (SPI) sponges was prepared using a freeze-drying process. The effect of the SPI content on the structure of the sponges was characterized by Fourier transform infrared spectrometry (FT-IR), X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). It showed that the sponges were porous in structure, and that the size of the pores increased and the thickness of the pore walls decreased as the SPI content of the sponges increased.