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At least 649 records · Page 36Linked to original sources
PubMed1991

Cranioplasty of an extremely large cranial defect caused by transitional meningioma with a knitted polypropylen-polyester prothesis "Codubix".

The authors report a case of transitional cell meningioma of the convexity which destroyed a large portion of the calvarium and invaded subcutaneous tissue. The tumour was totally removed and a large cranial defect/430 cm2 in size/was filled with a polypropylenopolyester knitted prothesis "Codubix" with an excellent result. The problems of chronioplastic closure of such an unusually large skull defect and the advantages of the use of the material "Codubix" are discussed.

Adult↗
PubMed1978

[Reaction of ocular tissues to scleral-implant and encircling material: polyamide--silicone--polyester (author's transl)].

Twenty-two human eyes and one rejected Silastic sponge were examined histopathologically for the reaction of ocular tissues to buckling and encircling materials. The eyes were enucleated 22 days to 14 years following retinal detachment surgery. Silicone implants, Silastic sponges, and Mersilene bands were very well tolerated by the eye, whereas nylon threads caused a moderate and prolonged granulomatous inflammation due to their susceptability to enzymatic decomposition. This reaction, however, does not seem to be of major clinical importance, as the amount of nylon used in detachment operations is low. Atrophy of the underlying sclera can happen with any of the above-mentioned materials and depends mostly on mechanical factors of the implant and on the intraocular pressure. Even with total transcleral erosion of the buckling or encircling material, no severe histopathologic changes could be found in the overlying choroid and retina.

Choroid↗
PubMedDate not supplied

Synthesis and biodistribution of Bowman-Birk soybean protease inhibitor conjugate with amphiphilic polyester.

The modification of Bowman-Birk soybean protease inhibitor (BBI) with the monoaldehyde derivative of block copolymer of ethylene oxide and propylene oxide (PE), M(r) 2,000 is described. The conjugate contains five covalently bound polymer chains per protein molecule, and retains the ability to inhibit trypsin and chymotrypsin-like proteinases. The distribution of native BBI and the BBI-PE conjugate was examined in mice. After i.v. injection of [125I]BBI and [125I]BBI-PE, both inhibitors distributed very rapidly to the liver, kidney, and lungs, and more slowly to the brain. At the same time-points (up to 24 h), radioactivity in the blood and organs of mice injected with modified inhibitor was higher than that of the native inhibitor. The blood concentration time profile following i.v. administration of two BBI preparations at a dose 3 mg/kg was reasonable well described by a two-compartment open model with first-order elimination kinetics. The total clearance of BBI-PE decreased by a factor of 8, body mean residence time increased by a factor of 5 in comparison with BBI. A physiological pharmacokinetic model was developed to describe the tissue-to-blood distribution of two inhibitors. One-compartment physiological organ model (flow limited) was used to describe of time-course profiles of BBI concentration in organs. A two-compartment physiological organ model (membrane limited) was used to predict tissue-to-blood distribution of conjugated BBI in some organs of mice (liver, lungs). The predicted concentration curves of BBI and BBI-PE in blood and organs in mice (with the exception of kidney) showed good agreement with the observed values.

Animals↗
PubMed2006

Production of a recombinant polyester-cleaving hydrolase from Thermobifida fusca in Escherichia coli.

The hydrolase (Thermobifida fusca hydrolase; TfH) from T. fusca was produced in Escherichia coli as fusion protein using the OmpA leader sequence and a His(6) tag. Productivity could be raised more than 100-fold. Both batch and fed-batch cultivations yield comparable cell specific productivities whereas volumetric productivities differ largely. In the fed-batch cultivations final rTfH concentrations of 0.5 g L(-1) could be achieved. In batch cultivations the generated rTfH is translocated to the periplasm wherefrom it is completely released into the extracellular medium. In fed-batch runs most of the produced rTfH remains as soluble protein in the cytoplasm and only a fraction of about 35% is translocated to the periplasm. Migration of periplasmic proteins in the medium is obviously coupled with growth rate and this final transport step possibly plays an important role in product localization and efficacy of the Sec translocation process.

Actinomycetales↗
PubMed1990

The biodegradability of polyester blends.

Blends of poly(epsilon-caprolactone) (PCL) and poly(L-lactic acid) (PLLA) with polyglycolic acid-co-L-lactic acid (PGLA) were prepared by three methods: compression moulding, coprecipitation, and solvent evaporation of a methylene chloride-in-water emulsion of the polymers. The rates of hydrolytic chain scission of each component of the blends were determined by deconvolution of GPC traces of samples maintained in phosphate buffer, pH 7.4, 37 degrees C, for up to 3000 h. The observed rates were dependent on the method of blending. For compression moulded blends, the rate of chain scission of PGLA was decreased and that of PCL and PLLA increased. A corresponding delay in the onset of weight loss was also observed. There was no evidence of blend miscibility.

Biodegradation, Environmental↗
PubMed1994

Use of styrene monomer-modified polyester in the fabrication of tissue-equivalent phantoms.

Tissue equivalent materials are often required both for routine quality control and for specialized studies in radiological physics. This work describes techniques and materials for casting of dosimetry devices from a widely available commercial resin suitable for use in a radiotherapy clinic. Methods are described for mixing and curing the material in such a way as to ensure complete reaction of the resin while maintaining a safe exothermic temperature. The clear plastic form of the cured resin is particularly useful for aligning measurement devices in the radiation field. Its specific gravity and narrow beam attenuation characteristics are similar to those of acrylic. The dosimetric characteristics of the material are reported, and its use in the construction of a patient phantom is described.

Humans↗
PubMed2005

Tissue engineering of bone on micropatterned biodegradable polyester films.

In this study, the effect of cell alignment on proliferation and phenotype expression of rat bone marrow derived osteoblasts on micropatterned (MP) PHBV and P(L/D,L)LA films with 27 microm wide parallel microgrooves was investigated. Immobilization of fibrinogen (Fb) on film surface by adsorption increased hydrophilicity, while covalent immobilization decreased it. Amount of Fb immobilized was significantly higher upon covalent bonding (153.1+/-42.4 microg Fb/cm2) than when adsorbed (10.0+/-3.3 microg Fb/cm2). It was observed that the presence of MP did not influence cell proliferation in the long run. Osteoblasts on MP films with adsorbed (MP Fb(a)) and covalently immobilized Fb (MP Fb(i)) aligned parallel to the groove axis with mean deviation angles of 10.59+/-23.47 and 29.02+/-33.03 degrees, respectively, while on tissue culture polystyrene (TCP), on unpatterned films (UNP) and on UNP with adsorbed Fb (UNP Fb(a)) alignment with an arbitrary axis was much higher: 46.66+/-24.98, 48.72+/-31.19, 47.74+/-27.29 degrees, respectively. Fb-free MP films were not effective in cell alignment, and clumps were formed. Cell alignment achieved on MP Fb(a) films did not influence cell proliferation, but increased differentiation, as shown by ALP activity per cell and the evenness and the amount of calcium phosphate deposition. It was concluded that orientation of cells was influential on their differentiation and also, MP cell carriers with chemical cues on their surfaces are important in improving tissue repair.

Animals↗