Advanced Materials Research Vols. 535-537

Abstract: The extraction of proteins from coconut meat was performed utilizing alkaline extraction. On the basis of single factor experiment, an orthogonal experiment was designed to optimize the extraction conditions (including extraction time, temperature, NaOH concentration and liquid to solid ratio). The highest extraction rate (7.3%) was obtained at 120 min, 45 °C, 0.1 M and liquid-solid ratio 25:1. Coconut protein was consequently hydrolyzed with four commercial enzymes (alcalase, trypsin, pepsin, papain). Furthermore, activities of hydrolysates on DPPH radical scavenging and ACE inhibition were assayed respectively. The results indicated that pepsin hydrolysate exhibited the highest DPPH radical scavenging activity (100%, 1 mg protein/mL), and trypsin hydrolysate possessed the most potent ACE inhibitory activity (40.2%, 1 mg protein/mL).

Abstract: Corn silk polysaccharide (CSP) was investigated for the treatment of different kinds of diseases. In order to characterize the chemical properties and antioxidant activities of CSP, the CSP was isolated from corn silk and purified by DE-52 cellulose column chromatography. Four components were separated, and the highest one named CSP-A. The CSP-A was characterized by FTIR and the monosaccharide components were analyzed by HPLC. The FTIR spectra indicated that CSP-A was characteristic of β-glucosidic bond and α-glycosidic bond. The CSP-A mainly comprised of glucose, galactose, arabinose, mannose, rhamnose. The antioxidant activities of CSP were determined by hydroxyl radical (•OH) and DPPH radicals scavenging assays. When the concentration of CSP was 10mg/mL, the scavenging capacity of •OH and DPPH could reach to 40% and 48%, respectively.

Abstract: This paper investigates the preparation and electrospinning of acidified-oxidized potato starch. In this article, acidified-oxidized potato starch was prepared by adding ammonium persulfate as an oxidizing agent and hydrochloric acid as a catalyst. The effect of reaction time, temperature, the concentration of hydrochloric acid and the content of ammonium persulfate on the viscosity and content of carboxyl were discussed. The optimum reaction conditions were as follows: 1.5 hours ,50°C, 0.5mol/l HCl, 2.5% (NH4)2S2O8. And then, the acidified-oxidized potato starch prepared at the optimum condition was dissolved in dimethyl sulfoxide (DMSO) to be electrospinned by contrast to native starch. Electrospinning of 5wt%-21wt% of modified starch in DMSO produced beads, beaded fibers, and smooth fibers, depending on the concentration range. Smooth fibers were observed until the concentration reached 19wt%, while native starch was 5wt%.

Abstract: Worm-like vaterite crystals were directly formed via an oriented attachment progress from nanocrystals in the presence of 50% volume ration of dimethyl sulfoxide (DMSO) at ambient temperature. The complex and unusual morphogenesis of the precipitated vaterite under ambient experimental conditions may imply that a simply synthesis routine which can be provided for certain materials with special morphologies.

Abstract: A beads based on cellulose and the room temperature ionic liquid 1-butyl-3-methyl imidazolium chloride ([Bmim]Cl) was prepared. Regenerated cellulose beads were modified with silane, and characterized by scanning electron microscopy. Papain was immobilized on the beads used two different methods including glutaraldehyde and covalent cross-linking method. The immobilized enzyme activity of bead was determinated by BAEE (N-benzoyl- DL-arginine ethyl ester hydrochloride) determination. According to the enzyme activity and immobilization rate compared with covalent cross-linking method, glutaraldehyde cross-linking method is more suitable for amino-modified.

Abstract: In this work, strain Phanerochaete chrysosporium producing cellulase was studied by fermentation process. Carbon source involves cellobiose, xylose, xylan, carboxymethylcellulose sodium, avicel, filter paper, corn stalk and glucose. Peptone, yeastextract, carbamide, ammonium nitrate, ammonium sulfate were researched for nitrogen source. Under the conditions of carbon source avicel, nitrogen source ammonium, the activity assays on different enzymes of respective component is optimum. Ultraviolet ray and nitrosoguanidine,were applied to mutate Phanerochaete chrysosporium. The optimal conditions were as follow: 60S and 50min. Colony morphology with obvious variation was used as sceening index. 120mutants were selected, carboxymethyl cellulose activity of cach mutant was determined and 20 strains with 30% increasing of cellulose activity were screened.GD3 mutant was obtained, with the increasing rate of filter paper activity 30.50%.

Abstract: Because of the good biocompatibility, silk fibroin is widely applied in the biomedical area. However, a few of sensitive persons still have the allergic effect after receiving the recovery treatments involving the silk fibroin used. In present research, we had the SD rat dermal cells cultured on the silk fibroin film (irradiated by gamma ray with the doses of 25kGy and 50kGy) and tested the cell grown curve and proliferation activity of the cells in the silk fibroin extracts from the CCK-8 test kit. The result showed that the cells cultured on the 50kGy-irradiated film grown more quickly than that on the 25kGy-irradiated film and the control. Moreover, cells in the 50kGy-irradiated film extract had the most proliferation activity. In conclusion, the results indicated that the silk fibroin irradiated with higher gamma ray dose could stimulate the cells growth and proliferation.

Abstract: Silk fibroin has been a raw material for many artificial biomaterials for a long term, because of it good mechanical property and fantastic biocompatibility. As a natural protein, it has more excellences than other chemically synthetical materials. In present, silk fibroin is used to manufacture bone repair material, artificial blood vessel, microcapsules and so on. However, silk fibroin-based biomaterial is not good enough in biodegradation. In our research, we exposed the silk fibroin film under the gamma ray irradiation with the doses of 25kGy and 50kGy and implanted the film subsequently on the back of SD rats. At dates (7th, 14th, 28th, 56th, 84th ) after implantation, we got the tissue with the implanted film and had the pathological analysis accordingly. The results show that the immune cells infiltration and inflammation decreased within a month. And the immune reaction decreased more quickly in the 50kGy group. And cracks of the silk fibroin film appeared earlier in the 50kGy group. From above observation, it is indicated that the silk fibroin film with a higher dose had better biocompatibility than others. And the silk biodegradation was accelerated by the higher gamma ray dose. Therefore, we can conclude that the gamma ray is able to improve the biocompatibility of silk fibroin and accelerated the biodegradation of it.

Abstract: Biodegradable cellulose/collagen beads were successfully prepared by coagulating a blend of cellulose and collagen using 1–butyl–3–methylimidazolium chloride ([C₄mim]Cl). The copper ions (Cu(II)) adsorption from aqueous solutions using the prepared beads were investigated at 15 °C as a function of initial concentrations, adsorbents types and adsorption time. The results show that Cu(II) adsorption amount increases with increasing initial concentration. Cellulose/collagen beads can absorb more Cu(II) than cellulose beads and the adsorption equilibrium can be achieved at 30 min. The maxinum adsorption amount of the cellulose/collagen beads (1/1, wt/wt) is estimated to be 0.51 mmol/g. The 90% absorbed Cu(II) on the composite beads can be desorbed by treating with 1 mol/L HCl solution for 180 min.

Abstract: The surface microstructure transition of pearl induced by rare earth element (REE) cerium (Ce) was investigated in micrometer scale range by means of scanning electronic microscopy (SEM). We found that pearls cultured in the control group (no REE Ce added) relatively grow slowly when there is in the culturing water, but the pearls grow quickly when REE Ce was added in the culturing water. At the same time, the former pearls were built up by aragonite blocks with spindly shape, but the latter pearls sampled in the REE test group are made of aragonite blocks with regular hexagonal shape. Moreover, the luster of the pearls free of REE Ce is relatively low because their surface were mainly build up by spindly aragonite blocks. On the contrary, the pearls with REE Ce have high luster since their surface were chiefly composed of regular hexagonal aragonite blocks that is the most idea blocks in crystallography. The results show that a quantity of Ce will promote the development and growth of pearls, and enhanced the lustrous of pearls significantly. Finally, we discussed the relevant of surface microstructure and lustrous of pearls to the concentration of REE in culture water by analyzing the influence of additive REE Ce on the surface microstructure