Fabrication of porous poly(L-lactide-co-ε-caprolactone) micropowder for microbubble effect and ultrasound-mediated drug delivery.

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.

Bio-Physical Properties of Acetylated Chitosan/Poly(ɛ-Caprolactone) Composites for Three-Dimensional Printing Material Applications.

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.

Dual-functional anti-adhesion barrier prepared using micro-hierarchical structured and neutralized shellac films for drug release.

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.

Enhanced Photocatalysis of Co-Doped Titania by Mn/WO₃ Under Visible Light Irradiation.

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.

Detecting changes in arthritic fibroblast-like synoviocytes using atomic force microscopy.

The morphological and quantitative differences between arthritic fibroblast-like synoviocytes (FLS) and normal FLS were determined as an effective diagnostic tool for rheumatoid arthritis (RA), and confirmed using atomic force microscopy (AFM). Collagen-induced arthritic (CIA) mice and normal mice were prepared and FLS were isolated by enzymatic digestion from the synovial tissue of sacrificed mice at 5-week and 8-week pathogenesis periods. Analysis of cell morphology using AFM revealed that the surface roughness around the nucleus and around the branched cytoplasm was significantly higher in CIA FLS (P < 0.

Enhanced biocompatibility and adhesive properties of modified allyl 2-cyanoacrylate-based elastic bio-glues.

Despite cyanoacrylate's numerous advantages such as good cosmetic results and fast application for first aid, drawbacks such as brittleness and local tissue toxicity have limited their applicability. In this study, to improve both the biocompatibility and mechanical properties of cyanoacrylate, allyl 2-cyanoacrylate (AC) was pre-polymerized and mixed with poly(L-lactide-co-ɛ-caprolactone) (PLCL, 50:50) as biodegradable elastomer. For various properties of pre-polymerized AC (PAC)/PLCL mixtures, bond strength, elasticity of flexure test as bending recovery, cell viability, and in vivo test using rat were conducted and enhanced mechanical properties and biocompatibility were confirmed.

Color assimilation of resin composites with adjacent color according to the distance.

Statement Of Problem: Color of esthetic restorative materials shifts toward color of adjacent material.

Purpose: The purposes were to determine the amount of distance-dependent color shift in resin composites toward the color of adjacent materials and to define a color shift parameter (CSP) that can quantify this phenomenon.

Methods: Three brands of resin composites, two shades for each, were investigated.

Fabrication of porous chitosan-polyvinyl pyrrolidone scaffolds from a quaternary system via phase separation.

Three-dimensional porous chitosan-polyvinyl pyrrolidone (PVP) scaffolds were fabricated for tissue engineering applications via liquid-liquid or liquid-solid phase separation. A mixture of an acidic aqueous solution with butanol as a non-solvent and a chitosan-PVP quaternary system were freeze-dried. We then studied the homogenous open pore structure and the minute pore distribution in order to improve the mass transfer and cell seeding efficiency while also obtaining the optimal ratio of PVP to provide high interconnectivity and to improve the open-pore structure.

Enhanced biocompatibility and adhesive properties by aromatic amino acid-modified allyl 2-cyanoacrylate-based bio-glue.

Cyanoacrylates have numerous advantages, including that they can be applied quickly during first aid and can provide good cosmetic outcomes, but they also have limitations in that they have a low bond strength and local tissue toxicity. Consequently, they are primarily used only in urgent applications. To improve both the biocompatibility and the mechanical properties of cyanoacrylate, allyl 2-cyanoacrylate (AC) was prepolymerized and mixed with a dopamine co-initiator.

Preparation of lotus-leaf-like structured blood compatible poly(ε-caprolactone)-block-poly(L-lactic acid) copolymer film surfaces.

Lotus-leaf-like structured poly(ε-caprolactone)-block-poly(L-lactic acid) copolymer (PCL-b-PLLA) films cast using the solvent-nonsolvent casting method. PCL-b-PLLA was synthesized by the well-known copolymerization process, and was confirmed by (1)H NMR analysis. The molecular weight of the synthesized PCL-b-PLLA was measured by gel permeation chromatography (GPC).

Lotus-leaf-like structured heparin-conjugated poly(L-lactide-co-epsilon-caprolactone) as a blood compatible material.

A heparin-conjugated biodegradable polymer was synthesized by direct coupling of heparin to poly(L-lactide-co-ɛ-caprolactone) (PLCL) and was manufactured into lotus-leaf-like structured films. We evaluated whether lotus-leaf-like structured heparin-conjugated PLCL (LH-PLCL) could be applied to blood vessel tissue engineering. Differences in the surface structures of the films with respect to hydrophobicity and the lotus effect as well as the antithrombotic efficiency in human whole blood were examined using scanning electron microscopy (SEM) and a contact angle meter.

Nanoscale imaging of morphological changes of umbilical cord in pre-eclampsia.

It is known that pre-eclampsia affects the structure of the umbilical cord including changes in diameter and wall thickness. In this work, the morphological changes of umbilical cords associated with pre-eclampsia were investigated using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The SEM images showed the overall structural changes in the umbilical cord, and the AFM imaged the surface of the cord in the nanometer range.

Effect of cross-linking with riboflavin and ultraviolet A on the chemical bonds and ultrastructure of human sclera.

This study examined the effect of the cross-linking with riboflavin-ultraviolet A (UVA) irradiation on the chemical bonds and ultrastructural changes of human sclera tissues using Raman spectroscopy and atomic force microscopy (AFM). Raman spectroscopy of the normal and cross-linked human sclera tissue revealed different types of the riboflavin-UVA and collagen interactions, which could be identified from their unique peaks, intensity, and shape. Raman spectroscopy can prove to be a powerful tool for examining the chemical bond of collagenous tissues at the molecular level.

Boric acid-enhanced embedding medium for cryomicrotomy.

A polyvinyl alcohol (PVA)/polyethylene glycol (PEG)-based resin is commonly used as a cryoembedding medium for the histological analysis of frozen tissue sections. However, it is not easy to obtain sufficient numbers of satisfactory reproducible sections owing to the differences between the mechanical properties of the medium and embedded tissue and the low cohesive force of the medium. We describe a modified PVA-based cryoembedding medium, composed of PVA (10wt% and 15wt%) with the addition of boric acid (from 0 to 5wt%), that can improve the sectioning properties and efficiency of frozen tissue for histological analysis.

Difference in the color stability of direct and indirect resin composites.

Unlabelled: Indirect resin composites are generally regarded to have better color stability than direct resin composites since they possess higher conversion degree.

Objective: The present study aimed at comparing the changes in color (ΔE) and color coordinates (ΔL, Δa and Δb) of one direct (Estelite Sigma: 16 shades) and 2 indirect resin composites (BelleGlass NG: 16 shades; Sinfony: 26 shades) after thermocycling.

Material And Methods: Resins were packed into a mold and light cured; post-curing was performed on indirect resins.

Perceived color shift of a shade guide according to the change of illuminant.

Statement Of Problem: The perceived color of shade guide tabs is influenced by different spectral compositions of different light sources, and this can influence color matching.

Purpose: The purpose of this study was to determine the amount of perceived shift in color and color coordinates of a shade guide using 3 different light sources: CIE standard illuminant D65 (daylight), A (incandescent lamp), and F9 (fluorescent lamp).

Material And Methods: CIE color coordinates L*, a*, b*, chroma, and the spectral reflectance of shade tabs in a shade guide (Vitapan 3D-Master) were measured by a spectroradiometer under D65, A, and F9 simulators.

Correlations between spectroradiometric and spectrophotometric colors of all-ceramic materials.

Objectives: Color coordinates of translucent esthetic materials measured by traditional spectrophotometers (SP) would deviate from those measured by newly introduced spectroradiometers (SR), which might simulate the clinical viewing condition better. This study aimed to determine the correlations in the SP- and SR-based color coordinates and color differences of all-ceramic materials.

Methods: Specimens for seven A2 shade core ceramics (n=7) and corresponding A2 and A3 shades veneer ceramics (n=7) were fabricated in clinically relevant thicknesses (1.

Preparation of interconnected porous chitosan scaffolds by sodium acetate particulate leaching.

For tissue-engineering applications, a 3D porous chitosan scaffold was simply prepared from a mixture of acidic chitosan solution and sodium acetate particles as the porogen by a salt-leaching method. Differences in the porous structure in terms of pore morphology and interconnectivity between the salt-leached chitosan scaffold and phase-separated scaffold as the control were examined by using scanning electron microscopy, protein release and enzymatic degradation tests. A fibroblast (NIH-3T3) cell culture was performed for cell affinity evaluation.

Simple polyacrylamide affinity gel electrophoresis using oleic acid for the isolation of chymotrypsin inhibitor.

Protease inhibitors have been usually isolated through a number of steps using various chromatographical methods, which are time consuming and tedious. In this report, an efficient and low-cost acrylamide affinity gel electrophoresis method for the detection and isolation of chymotrypsin inhibitor from a crude extract was studied. The affinity gel was obtained by immobilization of chymotrypsin on 5% (w/v) poly acrylamide-oleic acid gel, and the immobilized chymotrypsin showed high stability under varied concentrations of urea (0 to 8M), pH (4 to 10) and temperature (30 to 80 degrees C).

Effects of aging and HEMA content on the translucency, fluorescence, and opalescence properties of experimental HEMA-added glass ionomers.

Changes in the translucency, fluorescence, and opalescence of experimental 10-50% 2-hydroxyethyl methacrylate (HEMA)-added glass ionomers (HAGIs) after 5,000 cycles of thermocycling were determined and compared with those of commercial resin-modified glass ionomers (RMGIs). Changes in the translucency (TP), fluorescence (FL), and opalescence (OP) parameters were in the range of -3.5 to 0.

Modified paraffin wax for improvement of histological analysis efficiency.

Paraffin wax is usually used as an embedding medium for histological analysis of natural tissue. However, it is not easy to obtain enough numbers of satisfactory sectioned slices because of the difference in mechanical properties between the paraffin and embedded tissue. We describe a modified paraffin wax that can improve the histological analysis efficiency of natural tissue, composed of paraffin and ethylene vinyl acetate (EVA) resin (0, 3, 5, and 10 wt %).

EVA-enhanced embedding medium for histological analysis of 3D porous scaffold material.

When sectioning a 3D porous scaffold made of a soft elastomeric material embedded in paraffin medium, it is not easy to obtain a section because of the different mechanical properties of the paraffin and tissue/scaffold. We describe a new embedding material for histological analysis of various biomaterials that is composed of paraffin and ethylene vinyl acetate (EVA) resin (0, 3, 7, and 13 wt.%).

Oleic acid-added embedding medium for histological analysis of hard tissue.

For the histological analysis of hard tissue such as bone, various acrylate-based materials have been used as an embedding medium. However, commercial embedding media are expensive, and cutting the embedded block takes a long time. In this study, mixtures of methyl methacrylate (MMA), di-butyl-phthalate (DBP), and oleic acid (OA) were tested for possible application as an embedding medium for large and small undecalcified bone specimens.

Influence of TiO2 nanoparticles on the optical properties of resin composites.

Objectives: To determine the influence of titanium dioxide (TiO2) nanoparticle addition on the opalescence, color, translucency and fluorescence of experimental resin composites.

Methods: A light curing resin matrix was made by mixing 60 wt.% Bis-GMA and 40 wt.

Fabrication of collagen hybridized elastic PLCL for tissue engineering.

Biodegradable elastic poly(L-lactide-co-epsilon-caprolactone) (PLCL) (50:50) copolymer was blended with collagen (0.05, 0.1 and 0.