Advanced Materials Research Vol. 898

Abstract: Contamination of dental casts can occur via direct contact with impression materials that are contaminated by patients fluids. Thus, the development of dental stone with antimicrobial activity to reduce cross-contamination between patients and laboratory personnel is needed. This study aims to evaluate the influence of incorporation of disinfectants into type IV dental stone on its antimicrobial activities and physical properties such as setting time and dry compressive strength. Type IV dental stone incorporated with 4 types of disinfectants; Diamond Rock D (3-iodo-2-propynylbutylcarbamate), Diamond Rock B (zeolite), Diamond Rock Z (thiabendazole) and Diamond Rock T (2-benzimidazole carbamic acid), were tested in this study compared with the control, Diamond Rock O (type IV dental stone without disinfectant). Microorganisms tested were Staphylococcus aureus ATCC 6538, Pseudomonas aeruginosa ATCC 27853 and Candida albicans ATCC 1023. One hundred μL of each microbial suspension (10⁸ CFU/mL) was dropped on hydrocolloid impression (Jeltrate; Caulk/Dentsply, Milford, DE) and left dry. All types of stone mixes were prepared and poured into the impressions and allowed to set for 60 min. Then the stone samples were removed and the microbial contact surfaces were imprinted on Brain Heart Infusion agar plates. After incubation, colonies appeared on agar were gram-stained and counted. The setting time and dry compressive strength were tested in accordance with International Standard (ISO) 6873: 1998 (E). Dental stone incorporated with 4 types of disinfectants showed antimicrobial activity against all tested microorganisms with the percentage of microbial reduction ranging from 83% to 100%. Among all types of dental stone, no significant difference in setting time was observed. In dry compressive strength testing, the disinfectant-containing dental stone had significant higher strength than that without the disinfectant. The newly developed type IV dental stone incorporated with disinfectants had antimicrobial effects against all tested microorganisms. The physical properties of the modified dental stones were within the ISO standards. However, further investigation on other properties such as dimensional stability, detail reproduction and clinical usage are still needed.

Abstract: Thermo-responsive elastin-like polypeptides (ELPs) were successfully obtained by inverse transition cycling (ITC) and recursive directional ligation (RDL). Six ELPs displayed thermal properties, depending on their sequence and chain length. It was found that the ELP[KV8F-4 and ELP[KV8F-8 were effective as thermosensitive materials at the body temperature with phase transition temperature from 35 to 45oC.

Abstract: A local drug delivery system constituted by hybrid microsphere/thermosensitive hydrogel was fabricated for Osteoarthritis (OA) therapy in the research. The hydrogel were synthesized by ring-opening copolymerization. Microsphere was fabricated by O/W emulsion and solution evaporation method. The properties of the products were characterized by ¹HNMR, FTIR and phase transition diagram. The microsphere/hydrogel was prepared for in vitro drug release research. The results showed microsphere/hydrogel hybrid system can alleviate initial burst release. After 650 hours, only 60 percent of the drugs were released. Kinetics research implied the drug release is controlled by diffusion/erosion mechanism.

Abstract: Here we report the development of Poly Urethane (PU)/ graphene oxide composite used as the scaffold of anterior cruciate ligament tissue engineering. The influences of the GO on the composite were studied by FTIR, SEM and XRD. The Youngs modulus of the composite is 30.6 MPa compared to that of PU`s 6.8 MPa. The GO induced heterogeneous crystal increasing should be the reason for the composite modulus improving, as well as the interaction between the GO and PU. The good biocompatibility of the composite testified by cell viability experiment indicates the promising candidates of the material as the ACL tissue engineering scaffold.

Abstract: A novel electrochemical sensor has been developed based on the specificity of the molecular recognition of human neutrophil elastase (HNE) provided by its specific inhibitor, sivelestat. First, the gold surfaces were modified with homogeneously mixed cysteamine and 6-ferrocenyl-1-hexanethiol (FcHT) to generate a mixed self-assembled monolayers (mSAM) modified Au electrode. Then the sivelestat was covalently attached to the mSAM by its carboxylic group to the amino group with the use of activating reagents: 1-ethyl-3(3-dimethylaminopropyl)-carbodiimide (EDC) and N-hydroxy-sulfosuccinimide (NHS). Cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) was used to monitor the sensor assembly and the recognition of HNE on surfaces. Upon the selective binding of HNE to the surface bound sivelestat, the redox potentials of the ferrocene moiety of the mSAM shifted positively together with a decrease of the peak current. A clinically relevant range of HNE concentrations was successfully detected in pH 7.4 phosphate buffer.

Abstract: Unibract Fritillary Bulb,as a fomous type of traditional Chinese medicine, derived from Sicuan in China. The objective of the study is to evaluate a kind of DNA assay kit to detect of Unibract Fritillary Bulb from their counterfiets in addition to optimizing its components and protocols. All genomic DNA from 20 samples of Unibract Fritillary Bulb were extracted by Pharmacopoeia method recorded in the expanded edition of China Pharmacopoeia (2010) and assay kit respectively, the PCR technique and Restriction Fragment Length Polymorphism Analysis (RFLP) were carried out to identify the authentication of Unibract Fritillary Bulb. The maximum value of genomic DNA extracted by Pharmacopoeia method is measured as 1.57± 0.05 (OD260/OD280) by Ultraviolet Spectrophotometer, whereas, the value is 1.73±0.10 by assay kit. The results of PCR and RFLP indicated that a single band over 300bp was shown and two distinct bands between 100bp and 250bp in agarose electrophoresis. The data demonstrated that the assay kit was better than the Pharmacopoeia method, especially in extraction quantity and DNA purity of the Unibract Fritillary Bulb nucleic acid; the PCR and RFLP results shown the two methods were consistent compeletiy. The DNA detection Kit for identification of Unibract Fritillary Bulb have good specificity, high sensitivity as well as strong stability, so it is suitable for the rapid detection of Unibract Fritillary Bulb.

Abstract: Sponge-like scaffold with a specific three-dimensional structure resembling the actual extracellular matrix of a particular tissue show significant potential for the regeneration and repair of damaged anisotropic tissues. In this research, an oriented microtubular P34HB scaffold was prepared successfully. The mechanical property showed that anisotropy of modulus is much greater than a typical non-oriented scaffold. Altering the P34HB concentration allowed P34HB scaffolds to be produced with complex pore orientations, and anisotropy in pore size and alignment.

Abstract: Scaffold plays an important role in tissue engineering. In this study, porous PLGA scaffold was successfully prepared by mixed solvent systems using the thermally induced phase separation method. The PLGA scaffold shows fibrous matrix and interconnective pores, and the scaffold has high porosity and compressive modulus with dioxane/THF solvent system, which could be a very promising scaffold for tissue engineering.

Abstract: First of all, whey protein concentrat was added to milk adjusting the proportion of casein and whey proteins to 40:60. And then milk was hydrolyzed by trypsin and flavourzyme (TF) single respectively in one-step process or staged in two-step process. The Antigen contents of α-lactalbumin (α-LA) and β-lactoglobulin (β-LG) during the hydrolysis process were determined by indirect competitive enzyme-linked immunosorbent assay (ELISA) methods. The result showed that the most significant antigen reduction was observed in two-step hydrolysis process compared with one-step hydrolysis process

Abstract: Energy conservation is a longer period of a Chinas national policy, and the most important in economic sustainable development. With continuous rapid development in China's transport, problems as environmental pollution, high energy consumption, and low energy efficiency have arisen, which called for research, production and implementation of energy saving materials that would be the firm foundation of environmentally sustainable transport infrastructure in road traffic system. Currently, the application of advanced technology and brand new material used in pavement is beneficial for saving energy, reducing noise, and improving the economic viability of renewable energy. Various research projects have provided insights on how the use of energy efficient materials brings relatively exciting results as an essential prerequisite for sustainable development of the transport system. Therefore, the value of the broad application of sustainable, recycled materials utilized in road was clarified and illustrated by presenting some of the latest achievements in construction of sustainable infrastructure in road.