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Gel Solutions (gel + solution)
Selected AbstractsBioactivity, pre-osteoblastic cell responses, and osteoconductivity evaluations of the electrospun non-woven SiO2,CaO gel fabricsJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2009Yang-Jo Seol Abstract The evaluations of the fibers characteristics, bioactivity, pre-osteoblastic cell responses, and osteoconductivity of the non-woven SiO2,CaO gel fabric made by electrospinning method was carried out. Silica gels with four different calcium contents were prepared by condensation following hydrolysis of tetraethyl orthosilicate under acidic conditions. The molar ratios of Ca to Si prepared ranged from 0 to 0.15. SiO2,CaO gel fabrics were heat-treated at 300°C for 3 h after spinning under an electric field of 2 kV/cm. As the Ca to Si ratio increased, the diameter of electrospun SiO2,CaO gel fibers increased because the viscosity of the SiO2,CaO gel solution increased. The apatite-forming ability of heat-treated, non-woven SiO2,CaO gel fabric was evaluated in simulated body fluid and tended to increase with an increasing Ca to Si molar ratio. However, proliferation and differentiation tended to decrease with an increasing Ca to Si molar ratio. The sample which had the Ca to Si ratio as 0.10 showed good osteoconductivity in vivo in the calvarial defect New Zealand white rabbit model compared to that had the Ca to Si ratio as 0 and empty defect. These results strongly suggest that non-woven SiO2,CaO gel fabric made by the electrospinning method has potential for application as a bone grafting material. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009 [source] Simple method to determine flow characteristics of injectable hydrogelsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2010Sundar Babu Nadarajan Abstract This article presents a simple inexpensive method to measure flow and viscoelastic properties of calcium alginate hydrogels or gel solutions and is particularly suitable for quality control in small laboratory settings. This method can be considered an extension of the Melt Flow Index (MFI) method, which is routinely used in the polymer industry to indirectly determine the molecular weight of polymers. Results of alginate gels at various crosslinking densities obtained with this new test are compared to complex viscosity data obtained from a standard cone and plate rheometer, and demonstrate very good correlation. A mathematical model describing the apparent viscosity of the alginate gels in this test has also been developed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Investigation of the ultradrawing properties of gel spun fibers of ultra-high molecular weight polyethylene/carbon nanotube blendsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008Jen-Taut Yeh Abstract The carbon nanotubes (CNTs) contents, ultrahigh-molecular-weight polyethylene (UHMWPE) concentrations and temperatures of UHMWPE, and CNTs added gel solutions exhibited significant influence on their rheological and spinning properties and the drawability of the corresponding UHMWPE/CNTs as-prepared fibers. Tremendously high shear viscosities (,s) of UHMWPE gel solutions were found as the temperatures reached 140°C, at which their ,s values approached the maximum. After adding CNTs, the ,s values of UHMWPE/CNTs gel solutions increase significantly and reach a maximum value as the CNTs contents increase up to a specific value. At each spinning temperature, the achievable draw ratios obtained for UHMWPE as-prepared fibers prepared near the optimum concentration are significantly higher than those of UHMWPE as-prepared fibers prepared at other concentrations. After addition of CNTs, the achievable draw ratios of UHMWPE/CNTs as-prepared fibers prepared near the optimum concentration improve consistently and reach a maximum value as their CNTs contents increase up to an optimum value. To understand these interesting drawing properties of the UHMWPE and UHMWPE/CNTs as-prepared fibers, the birefringence, thermal, morphological, and tensile properties of the as-prepared and drawn fibers were investigated. Possible mechanisms accounting for these interesting properties are proposed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Reaction of rat pulp tissue to Carisolv ,new gel',-A histocytological evaluationAUSTRALIAN DENTAL JOURNAL, Issue 1 2006T. Dammaschke Abstract Background: This study was an histological examination of pulp tissue exposed to Carisolv ,new gel' after 1 to 28 days. Methods: An occlusal cavity was prepared in 64 caries-free molar teeth of 16 Wistar rats. The roofsof the pulp chambers were perforated and Carisolv ,new gel' solution was placed onto the exposed pulps of 32 molar teeth for 20 minutes. Thirty-two contralateral molar teeth served as controls and were coated with an inert liquid containing isotonic saline solution and carmellose for 20 minutes as well. The pulps of all teeth were capped with Ca(OH)2 and the cavities were filled with a flowable composite in combination with a self-etching dentine adhesive. The animals were sacrificed after 1, 3, 7 and 28 days. Eight teeth per group and the time period were histologically examined, scored, and statistically evaluated (Wilcoxon-test). Results: The results showed no statistically significant differences between the Carisolv group and the control group (p>0.05). The observed pulp reaction was essentially the same as those reported in the past being typical for the effect of calcium hydroxide as a direct pulp capping agent. Conclusion: Compared to Ca(OH)2, Carisolv ,new gel' did not cause any different or additional pulp reaction in healthy teeth. [source] | ||||||||||