The purpose of this study was to prepare a porous sponge-like scaffold and evaluate hard tissue formation in the scaffold. It is desirable for the scaffold to be modified its configuration easily in accordance with the defect of a tooth in clinics. Then, we developed sponge-like porous scaffolds from sodium alginate (AL) gel. Scanning electron microscopic observation found spherical and interconnected pores with appropriate size for osteogenesis in the scaffolds prepared from 4% AL gel by freeze-drying. Intensity of the scaffold was improved by cross-linkage of the gel with calcium chloride or addition of a tri-calcium phosphate (TCP) at 10% in the gel. Scaffolds prepared from 4% AL gel with 10% α-TCP showed significantly high level of osteocalcin and ALP activity. It might be because of cell adhesive property of α-TCP. It is concluded that 4% AL gel with 10% α-TCP would be suitable to prepare the porous sponge-like scaffold.
We examined the biological effects of the newly synthesized oligopeptide derived from Emdogain® (EMD) in Sprague-Dawley rat bone marrow (RBM) cells. Cell culture experiments were performed with RBM cells. The biological effects of the oligopeptides on RBM cells at five concentrations were determined by examining cell proliferation, cell adhesion, and chemotaxis. RBM cells were cultured in a suspension of 100 ng / mL oligopeptides and osteogenic supplements (the test group) and medium without the oligopeptides (the control group). Alkaline phosphatase (ALP) activity was measured after 7 and 14 days, and Ca deposition after 14 days. The test group showed significantly higher ALP activity and Ca deposition than the control group for each period. In conclusion, these data suggest that newly synthesized oligopeptide derived from EMD induces hard tissues formation to undifferentiated periodontal mesenchymal cells as well as RBM cells.
Purpose: The aim of this study was to examine effects of hydroxyapatite fiber (HF) combining with autogenous Bone on vertical bone augmentation.Materials and methods: Polytetrafluoroethylene chambers were fixed to the parietal bone on the right and left sides in thirty-six Japanese male white rabbits. HF only (30 or 60 mg) and combination of HF with autogenous bone from tibia at different ratios (30 mg bone/HF ratio: 3/1, 3/2, 1/1) were grafted into each chamber. Chambers were left empty in the negative control animals (empty group). Rabbits were sacrificed at 4 and 8 weeks. Then, total bone volume (TBV) of highly calcified bone region in the chamber was quantified with micro-CT analysis. Histomorphometric analysis was performed to evaluate the area of newly formed bone (BA). Statistical analysis was performed with the Student t-test and Tukey- Kramer's method.Results: In histology, newly formed bone conducted by HF showed a particular structure, and active bone regeneration was observed in the groups containing more HF at 8 weeks. From 4 weeks to 8 weeks BA was significantly reduced in the control, HF 30 mg and ratio 3/1 groups. At 8 weeks BA of HF 60mg was significantly higher than the one of HF30mg group.Conclusions: Combination of HF with autogenous bone was effective in vertical bone augmentation although optimal ratio of the combination needs further study.
The aim of the present study was to clarify the effect of physicochemical treatment of titania surfaces on protein adsorption. Two electrodynamically different proteins, albumin and lysozyme, were selected. Unmodified titania particles suspended in phosphate-buffered saline (pH 7.4) adsorbed albumin at a rate of 14.5%. When the titania particles were mixed with albumin after ultraviolet (UV) irradiation, the adsorption rate increased more than 2-fold to 30.7% (p<0.05). Conversely, when rutile-form titania was mixed with albumin, even after UV irradiation, the rate showed only a slight increase to approximately 15%. Lysozyme showed an adsorption rate of 34.6% to UV-irradiated titania particles and 30.6% to unmodified particles. At the pH of the test solution, the two targeted proteins showed an opposite charge. These results showed that UV-irradiation elicited a dramatic shift in the charge of the titania particles. This suggests that controlling the physicochemical nature of a scaffold, including its surface electrical charge, would enhance its viability in tissue engineering. We believe that this study will provide valuable information for the development of strategies aimed at control of protein adsorption and functionality in material surface modification.
Recovery of taste buds is one of the important targets of regenerative dentistry. Taste of the medicine will be heavily involved in regeneration of gustatory papilla. This experiment system using an electronic taste system is applicable to evaluation of gustatory papilla.There is no report of having proved scientifically about the taste of the value added generic drugs. In the present study, we measured objective taste of brand and value added generic drugs of the isosorbide liquid formulations using electronic taste system α-ASTREE®. The value added generics taste restrained the taste a little. In addition, the taste of isosorbide solution formulations was not restrained by the mineral water dilution, but it was largely restrained by the apple juice dilution.The present study was able to evaluate the taste of value added generic drugs by using the taste sensor system. And it was proven that it was one method of rising of the possibility that an effective drug therapy was able to be done by diluting it with the apple juice from these by the patient of the medication nonadherence of the isosorbide solution formulations by this research.
Complex mixtures of a DNA/protamine complex with 30%, 50%, and 70% DNA/chitosan complex were prepared for a soft type of membrane for guided bone regeneration. All complex mixtures showed flowable properties when kneading the mixture with distilled water. Increases in the mixture ratio of the DNA/chitosan complex in the complex mixture increased the consistency of flowable complex mixture. Differences in biodegradable rates among three complex mixtures were observed in vivo. Although the complex mixture with 30% DNA/chitosan complex completely disappeared, part of the other complex mixtures remained 3 months after implantation. Biodegradable rates of mixtures with higher volumes of the DNA/chitosan complex were slower. In conclusion, all complex mixtures showed flowable properties. Their consistency and biodegradable rates could be controlled by the mixing ratio between DNA/protamine and DNA/chitosan complexes. They are promising candidates for biodegradable membranes with adjustable biodegradable rates that form desired figures by hand during surgery.
Skin sensitization is also related to the dental field. In addition, the regeneration of skin and mucous membranes of the lips may be consulted from the patient. In silico assessment of skin sensitization is increasingly needed owing to the problems concerning animal welfare, as well as excessive time consumed and cost involved in the development and testing of new chemicals. We could perfectly classify skin sensitizers (positive/negative) using a newly developed K-step Yard sampling (KY) methods (U.S. Patent No. 7725413, 2010). Therefore, the KY methods could be applied to qualitative structure-toxicity relationships (QSTR) study on classifying and predicting samples.A total of 593 compounds (419 positive sensitizers and 174 negative sensitizers) were used in this study. Parameters were generated from 2-D and 3-D structures of compounds. All of the 1015 parameters generated were reduced by various feature selection methods. KY methods were performed using ADMEWORKS/ModelBuilder software. All 593 compounds were perfectly classified by 3 steps. Discriminant function of each step was a linear dicriminant function, the Iterative Least Squares linear discriminant (TILSQ). KY methods were referred to as a meta-algorithm approach because it requires ordinary data analysis methods to generate discriminant functions.KY methods were the repetition of removal of gray zone of samples and reclassification of them to attain no gray zone (100% classification) at final step. This methods always attain perfect classification at final step, even though samples are large number, large of structural diversity or highly overlapped on the sample space.KY methods are promising tool in QSTR technology.