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Biomedical subjects

E Masuhara

Publications and source records attributed to E Masuhara.

At least 37 records · Page 2Linked to original sources
PubMed1983

Structure-biocompatibility relationship of condensation polymers.

Various condensation polymers including polyamides, polyesters, polyethers, polysulfonamides, polysulfonate, polyphosphonate, polyimide, polyamide-imides, polyimide, polyamide-imides, polyester-amides, etc. have been prepared and evaluated for their biocompatibility by a cell culture method. Cell attachment and cell growth are influenced by the chemical structures of the tested polymers. Aliphatic polyamides exhibited considerably different cell growth behavior than aromatic polyamides.

Biocompatible Materials↗
PubMed1983

Studies on dental fluoride-releasing polymers. IV: Fluoridation of human enamel by fluoride-containing sealant.

An experimental fluoride-containing acrylic sealant was prepared using methacryloyl fluoride-methyl methacrylate copolymer as powder component. The in vitro fluoride acquisition by human enamel coated with the sealant after 11, 21, 41 and 84 days of incubation in a phosphate buffer of pH7 at 37 degrees C was determined. Fluoride penetration and uptake were increased by prolonging the exposure time of enamel to the sealant. Most of the fluoride retained in enamel was found to be present as fluorapatite. The discharge of fluoride in the sealant was about 12% of initial load after 84 days of immersion.

Apatites↗
PubMed1983

Action of drugs on liposomes with varying charges.

The effects of 12 amphipathic compounds--such as aromatic and aliphatic carboxylic acids, amines, imines, nitrogen-substituted derivatives, and aldehydes--on multilamellar liposomes with varying charges were monitored in biological systems. The stabilization-lysis action of amphipathic compounds on liposomes was influenced by either the electrostatic repulsion or the attraction force between these compounds and liposomes.

Aldehydes↗
PubMed1983

Nuclear magnetic resonance spectroscopic studies of the interaction of phospholipids with stabilizing lysosome agents.

The interaction between phospholipids and stabilizing lysosome agents such as acetylsalicylic acid (ASA), colchicine (CC), prednisolone (PD), etc., was studied using NMR spectroscopy. The peak intensity of protons arising from these compounds was reduced in liposomes containing lecithin and various agents with a molar ratio of 1:1 in D2O. The reduced percentage of protons in the agents differed due to their molecular structures: ASA was about 20%, CC about 30%, and PD about 100%.

Aspirin↗
PubMed1982

The promotion of adhesion by the infiltration of monomers into tooth substrates.

The effectiveness of 4-methacryloxyethyl trimellitate anhydride (4-META) on the adhesion of an acrylic rod with etched dentine and enamel was studied. Etching of tooth substrates with a 10% citric acid-3% ferric chloride solution prior to the adhesion proved effective. Monomers with both hydrophobic and hydrophilic groups like 4-META promoted the infiltration of monomers into the hard tissue. The infiltrated monomers polymerized in situ and good adhesion with the tooth substrates took place. The tensile adhesive strength was 18 MPa on the etched dentine. Scanning electron microscopic studies suggested that the monomers possess affinity with the hard tissue. The good adhesion was not provided by the interlocking at the tubules as had been considered previously.

Acid Etching, Dental↗
PubMed1982

The evaluation of new dental resins prepared with polyfunctional methacrylate monomers.

The combinations of several composite fillers and dimethacrylates for crown and bridge resins were investigated. The composite filler prepared from TMPT markedly improved the mechanical and physical properties of crown and bridge resins. The enhancement of the mechanical and physical properties is due to the highly crosslinked structure which is developed with the use of the reactive composite filler which copolymerizes with the matrix monomer. The combination of the 2.6E-UDMA comonomer and the TMPT composite filler exhibited the maximum compressive strength, transverse strength, and Brinell hardness, and minimum abrasion loss and thermal expansion. This hard resin was superior to the resins currently available for clinical use.

Acrylic Resins↗
PubMed1982

Long-term in vivo studies of poly(2-hydroxyethyl methacrylate).

Poly(hydroxyethyl methacrylate) (PHEMA) was implanted subcutaneously in rats, hamsters, and guinea pigs for up to 24, 23, and 13 months, respectively. The tissue response and tumorigenesis caused by PHEMA were compared among the three species of the animals. Thick fibrous capsule formation and tumor production were noted only in rats, while no tumorigenesis and thin fibrous capsule formation were observed in hamsters and guinea pigs. These results support our previous hypothesis that animals producing a thick and avascular capsule tend to develop tumors at the implant site. PHEMA retrieved was characterized by scanning electron microscopy and x-ray energy dispersive analysis. Calcium and phosphorus were the main elements detected on the surface of PHEMA implants. PHEMA is suggested to be not suitable for long-term implant material.

Animals↗
PubMed1982

Evaluation of the biologic effects of dental materials using a new cell culture technique.

The biological effects of seven dental cements--including zinc oxide-eugenol, EBA, silicate, zinc phosphate, silico-phosphate, polycarboxylate, and glass ionomer--and a composite resin were evaluated by a new cell culture technique. The agar overlay containing serum was proposed as a dentin model. The effects of thickness and serum concentration of the agar overlay on cell growth were studied and compared to in vivo findings. Some correlative phenomena between the cell culture results and in vivo data are presented.

Cells, Cultured↗