Several acrylate-based materials are commercially available as embedding resins for the histological analysis of non-decalcified hard tissues, including implants. However, commercial embedding resins are imported, expensive, and take a long time to buy. We conducted several tests to apply a mixture of methyl methacrylate and oleyl alcohol (oleyl Alc) as an embedding resin on a non-decalcified bone specimen. Further, we observed differences in the compressive strength of the block resin and the fused bone sample, changes in crystallinity, and a hydrophilic change in the block. Hematoxylin and eosin (H&E) and Masson's Trichrome (MT) staining were performed for the histological analysis of dog bones to compare staining characteristics. The block to which the resin with the optimal composition ratio was applied for embedding was confirmed experimentally to achieve optimal performance.

Shellac and alginate composites were prepared to enteric coating agent and obtained efficient drug release results. When shellac is used alone, low bending strength and an easily broken film are formed, but by adding alginate, the bending strength and hydrophilicity are improved. Also insoluble in acidic solution, and a composite that easily dissolves at a neutral pH can be obtained. The optimal shellac and alginate concentration was obtained through drug release, mechanical properties, and solubility tests under various concentrations. Drug release behavior and solubility were tested at various pH through absorbance of released dye and remaining weight, and the death of U-87MG cells was observed in a release test of disulfiram from composite. The composite prepared in this study will be able to be applied as a multipurpose coating agent that can achieve the effect of surgical anti-adhesion barrier, tissue engineered skin, and releasing various drugs.

Biodegradable elastic poly(L-lactide-co-ε-caprolactone) (PLCL) copolymer (50:50, lactide:caprolactone molar ratio) was synthesized and porous PLCL micropowders was fabricated by a simple method involving rapid cooling of 0.1, 0.5, and 1% (wt/vol) PLCL/dioxane spray into liquid nitrogen. The physicochemical properties of the porous PLCL micropowders were examined by measuring their pore size, pore morphology, and microbead size using a scanning electron microscopy (SEM) and dye and temozolomide (TMZ)-release testing under ultrasound. Human U-87MG, glioblastoma (GBM) cell culture tests were performed to evaluate cell cytotoxicity by released drug from PLCL micropowders. In this study, the porous PLCL micropowders prepared from 1 wt%/vol% PLCL solutions showed a highly porous structure, satisfactory mechanical properties, and optimal drug release efficiency compared with those produced from 0.1 or 0.5 wt%/vol% solutions. The results of the accumulated release test with the results of the absorbance of the dye initially applied, it was confirmed that more than 80% of the added dye was trapped inside the micropowder, and clearly GBM cytotoxicity effect could be observed by the released TMZ. The drug release system using micropowders and ultrasound can be applied as a drug supply system for various diseases such as brain tumors with low drug permeability.

TiO2 photocatalysts doped with various concentrations of Cr and WO3 were prepared by sol-gel synthesis to achieve stable photoactive reactions in the visible light region and to be applied to the glass surface. Their activity was measured and compared under a 500 W xenon light source by artificial sunlight using methylene blue and methyl orange decomposition methods, and Cr in a 3.8% molar ratio and 10 mg of WO3 were set as the optimum composition ratio. No change in the TiO2 crystal structure due to the doped atoms was observed through X-ray diffraction analysis. After dipping and coating the photocatalyst on a glass plate, the anatase phase structure, smooth surface, and enhanced photoactive properties were observed as a result of the same analysis. The photocatalyst manufactured using the components and composition ratios proposed in this study can be widely applied in industrial, medical equipment, and tissue engineering fields.

Polyvinyl alcohol (PVA) resin has been generally used as a resin for embedding for cryomicrotomy for rapid histological analysis in the operating room. However, due to the lack of cohesion and penetration of resin, and the relatively high freezing point, and the difference in the mechanical properties of resin and tissue, there have been difficulties in obtaining satisfactory intercepts. In this study, a modified PVA-based embedding resin composed of PVA and boric acid, which can improve histological analysis efficiency, and NaOH as a crosslinking reaction catalyst was studied. It was confirmed that as the amount of PVA, boric acid, and NaOH increased, physical properties including cohesion were improved. And complete tissue cross-section could be obtained without damage using 10 wt% PVA, 2 wt% boric acid, and 0.3 wt% NaOH composition, and hematoxylin and eosin staining tests showed clear tissue images. The modified PVA-containing resin of this study is expected to improve the rapid histological analysis efficiency of various biological tissues.

For three-dimensional (3D) printing material applications in tissue engineering, acetylated chitosan (AC)/poly(ɛ-caprolactone) (PCL) composites were prepared by the melt mixing method using the acetylation of chitosan with PCL. The physiochemical properties of the AC/PCL composites were examined by measuring the water contact angles, dispersity of AC on the cross-section using scanning electron microscopy, and temperature stability. In addition, mechanical properties such as tensile strength and bending stress recovery were measured to determine the elasticity of the composite films. The fibroblast cell line NIH-3T3 was used to test the relative cell affinities based on the AC content and cell viability on AC/PCL at various temperatures. There was no difference between the melting points and tensile strengths of the AC/PCL composites and pure PCL. Overall, the AC/PCL composites showed high initial cell adhesion after 4 h of cell culture and increased cell proliferation compared to those of PCL composites used as a control. Based on these tests, an AC of 10.7 wt% was determined to be the optimal composition for the AC/PCL composite. Thus, these composites can be used in various 3D printing material applications in tissue engineering.

Shellac and polyvinyl acetate (PVAc) composites were prepared to protect teeth and obtain a drug release effect. When shellac is used alone, low friction resistance and a easily broken film are formed, but by added polyvinyl acetate and calcium phosphate, the friction resistance is greatly improved, and a stable film state is obtained. The optimal PVAc and calcium phosphate concentration could be obtained through tests using various concentrations. Drug release behavior was tested at neutral and acidic pH through a dye release test, and the death of U-87MG cells was observed in a release test using temozolomide. The composite prepared in this study can be used as a multi-purpose tooth coating agent that can achieve the effect of protecting teeth, coloring specific colors, and releasing drugs.

Basic cell studies on a strong anionic poly(cresolsulfonic acid) and a cationic pyrvinium have been conducted to develop therapeutic drugs for glioblastoma, the most malignant brain tumor. To determine the optimal concentration of these mixed drugs, experiments on the cell shape change and survival rate were conducted, and cell resistance was tested through the re-administration of drugs. Through immunochemical testing, the mechanism for cell morphological changes and inhibition of proliferation could be inferred, and when used in combination with temozolomide, the mixture showed a greater cytotoxic effect. Further research is needed on the mechanisms, cell reactions, and animal testing, with a possibility to develop it as a therapeutic drug.

Poly(L-lactide-co-epsilon-caprolactone) (PLCL) was synthesized, and this was mixed with TiO2 for tooth manicure. A mechanical test was conducted using a tensile strength testing machine and pencil hardness tester; these tests indicated that the optimal molar ratio of lactide in PLCL was 50%. Differences in the surface structures of the films with respect to the hydrophobicity and the whitening effect were examined using a digital microscope, a contact angle meter, and colorimeter. The optimal ratio of TiO2 for the composite was determined to be 10%. The composite coated glass plate yielded a good cell adhesion rate in fibroblasts. The TiO2/PLCL composite manufactured by this simple method can be applied to implantable dental materials, used for tooth whitening, and as a protecting agent during tooth manicures.

Micro-hierarchical structured shellac films were prepared using a solution casting method with dodecyltrichloro-immobilized shellac microparticles. We evaluated two opposite surfaces of the shellac films-one a micro-hierarchical structured side and the other a neutralized shellac side using alkali ethanol-for their applications in the medical field. A bending strength test using a tensile strength testing machine and measurement of surface hardness using a scratch hardness tester indicated that the optimal composition of the base films comprised 15% shellac and 10% calcium phosphate as durability promoting agents. Further, dodecyltrichloro-immobilized shellac microparticles were synthesized and spray-deposited on the films. The solubility of shellac increased as the pH of the shellac solution increased. Analyses of cell adhesion, proliferation, and anti-thrombus efficiency were performed using a WST assay, field emission scanning electron microscope, and hemocytometer. The contact angle with the micro-hierarchical structure surface was approximately 150°. The spray-deposited shellac film yielded a lower cell and platelet adhesion rate (20%) than the untreated film. These results indicate that the micro-hierarchical structure has unique properties and that this novel superhydrophobic biodegradable shellac film can be applied as a blood/tissue-compatible, biodegradable material for implantable medical devices that need an anti-adhesion barrier.

Abstract Biodegradable elastic poly(l-lactide-co-ɛ-caprolactone) (PLCL; 50:50) copolymer was synthesized, and 3D self-assembled porous microbead-type PLCL scaffolds were fabricated by a simple meth...

For medical applications, cell selective double-sided membranes (LA-chitosan) were prepared by the acetylation of chitosan and dodecyl trichloro-immobilized SiO2 nanoparticles. We evaluated two opposite surfaces of chitosan-the lotus-leaf-like structured side (L-side) and the acetylated side (A-side)-for their applications in the medical field. The optimal reaction time for the acetylation of chitosan was determined by measuring cell adhesion and proliferation and analyzing the functional groups using IR-spectroscopy. Moreover, dodecyl trichloro-immobilized SiO2 nanoparticles were synthesized and sprayed on one side of the membrane following the pre-treatment with instant bioglue. The cell affinity and surface morphology were studied using the WST assay and field emission scanning electron microscope. The contact angle with the lotus-leaf-like surface was approximately 161 degrees. Furthermore, the L-side yielded a lower cell adhesion rate (approximately less than 1%) in comparison with an acetylated chitosan membrane. Contrarily, the A-side demonstrated increased cell adhesion and a proliferation efficiency over 2.5 times that of pure chitosan. This novel LA-chitosan membrane could thus be applied as a blood/tissue-compatible biodegradable material for implantable medical devices including dental membranes and anti-adhesion barriers.

TiO2 was co-doped with Mn/WO₃ with varying concentrations of Mn, and its photocatalytic activity was evaluated by carrying out the degradation of methylene blue using it under visible-light illumination. The X-ray diffraction and photocatalytic activity results revealed that the crystallinity and photocatalytic activity of the co-doped TiO₂ decreased with an increase in the Mn concentration. The optimal Mn/Ti ratio was 0.17%, at which the photocatalytic activity of TiO₂ enhanced by a factor of 1.8. The photocatalysts exhibited superhydrophilic properties when coated onto glass plates using a dipping method. The photocatalysts fabricated using the simple method proposed in this study can be widely used in industry, medical devices, and tissue engineering.

For soft tissue engineering applications, 3-D macroporous acetylated chitosan/poly(l-lactideco-ε-caprolactone) (PLCL) scaffolds were prepared by acetylation and particulate leaching using sodium acetate in an acidic water/dioxane solution. Acetylated 5 wt% chitosan/PLCL scaffold of 90% porosity was determined and confirmed through various tests. The physiochemical properties of acetylated chitosan/PLCL hybrid scaffolds were examined by measuring water contact angles, pore morphology and interconnectivity using scanning electron microscopy (SEM), and dye release testing. In addition, mechanical properties such as tensile strength and bending stress recovery for determining the elasticity of scaffolds were measured. The fibroblast cell line NIH-3T3 was used to test relative cell affinities for the acetylated chitosan/PLCL vs. normal chitosan/PLCL films and porous scaffolds. The acetylated chitosan/PLCL films and scaffolds showed a high initial cell adhesion after 4 h of cell culture and increased cell proliferation compared to that of the control. The acetylated chitosan/PLCL scaffolds produced by particulate leaching showed a highly porous structure and improved the biocompatibility and stability of chitosan compared to that of chitosan-coated PLCL scaffolds. Thus, these scaffolds may be very useful for a variety of tissue engineering applications.

We attempted to create a durable superhydrophobic surface for prosthetic joints using titania-modified SiO2 nanocomposites coated on glass plates. Differences in the surface structures due to the modified SiO2 contents were examined in terms of hydrophobicity, hardness, crystallinity, and anti-adhesion efficiency of the fibroblasts. The optimal ratio was 9:1 (dip-coating solution:SiO2), and the water contact angle was 152 degrees. Furthermore, the composite-coated glass plate yielded a lower cell adhesion rate (<10%) than did an untreated glass plate. The titania-modified SiO2 nanocomposite created by this simple method can be used in implantable medical devices and tissue engineering as a durable superhydrophobic surface. (C) 2017 Elsevier B.V. All rights reserved.

To induce the antifouling activity of a chitosan filter of mask type under visible light such as daylight or xenon-lamp, Cr-doped TiO2 was synthesized and developed into Cr-doped TiO2 hybridized porous chitosan structures. We examined various properties such as morphology, crystallization intensity, mechanical strength, component analysis, water contact angle, and degradation efficiency of methylene blue as a measure of photocatalytic activity under xenon-lamp. We ascertained that it was optimal to combine 3 % Cr-doped TiO2, 1 % chitosan (molecular weight <1000 kDa), and an ultrasonic dispersing method to achieve good mechanical strength and optimal porous structure. Anatase Cr-doped TiO2 was successfully obtained after sintering at 300 °C for 5 h. With the exception of 6 % Cr-doped TiO2, the porosity of these hybridized porous chitosan-based filters increased with an increase in Cr-doped TiO2 concentration. Furthermore, these filters showed a methylene blue degradation efficiency of 86 %. These results indicate that Cr-doped TiO2 hybridized porous chitosan-based filters can be widely used as smart filters for self-cleaning and antifouling applications.

To improve the biocompatibility and physical properties of bioadhesives for hard tissue, allyl 2-cyanoacrylate (AC) was pre-polymerized and mixed with bisphenol A glycidyl methacrylate (bis-GMA) and hydroxyapatite (HA). Various properties of pre-polymerized AC (PAC)/bis-GMA mixtures were measured, including compressive and shear bond strength, polymerization shrinkage, surface properties, and cytotoxicity (tested using L929 cells); enhanced physical properties and biocompatibility were observed. In particular, the optimal ratio for PAC/bis-GMA/HA was determined to be 90/9/1wt%, as per the results of the above-mentioned measurements. Polymerization shrinkage of PAC/bis-GMA samples decreased with increasing bis-GMA content (by up to 15 times compared to PAC alone). Furthermore, biocompatibility and mechanical strength improved with increasing bis-GMA or HA content. Therefore, bioadhesives prepared with these PAC/bis-GMA/HA mixtures showed enhanced chemophysical properties compared to commercial bioadhesives for hard tissue. These results indicate that PAC/bis-GMA/HA materials can be used widely as advanced bioadhesives in various fields.

Simple poor-cosolvent casting was used to surface treat biodegradable elastic poly(L-lactide-co-epsilon-caprolactone) (PLCL; 50:50) copolymer films that presented lotus-leaf-like structures. We evaluated whether the lotus-leaflike-structured PLCL (L-PLCL) films could be used as a biomaterial for artificial vascular grafts. The surface morphology, hydrophobicity, and antithrombotic efficiency of the films were examined while immersed in platelet-rich plasma (PRP) using scanning electron microscopy (SEM) and a contact angle meter. The recovery and crystallinity of the films were measured using a tensile-strength testing machine and an X-ray diffractometer, respectively. The solvent containing acetic acid, as a poor co-solvent, and methylene chloride mixed in a 1:2 ratio produced an optimal PLCL film with a water contact angle of approximately 124 degrees. Furthermore, the surface of the L-PLCL films immersed in PRP showed a lower rate of platelet adhesion (<10%) than that of the surface of an untreated PLCL film immersed in PRP.