Search results for "Polyester"

showing 10 items of 221 documents

Durability of Biodegradable Polymer Nanocomposites

2021

Biodegradable polymers (BP) are often regarded as the materials of the future, which address the rising environmental concerns. The advancement of biorefineries and sustainable technologies has yielded various BP with excellent properties comparable to commodity plastics. Water resistance, high dimensional stability, processability and excellent physicochemical properties limit the reviewed materials to biodegradable polyesters and modified compositions of starch and cellulose, both known for their abundance and relatively low price. The addition of different nanofillers and preparation of polymer nanocomposites can effectively improve BP with controlled functional properties and change the…

Absorption of waterNanocompositeMaterials sciencePolymers and PlasticsPolymer nanocompositeOrganic chemistryGeneral ChemistryReviewBiodegradationBiodegradable polymerDurabilitybiodegradationcreepPolyestermodellingCommodity plasticsQD241-441biodegradable polymersenvironmental ageingnanocompositesdurabilityComposite materialPolymers
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Treatment of malar and midfacial fractures with osteoconductive forged unsintered hydroxyapatite and poly-L-lactide composite internal fixation devic…

2013

Purpose To evaluate the internal fixation of malar and midfacial fractures, long-term results, and biocompatibility of osteoconductive internal fixation devices composed of a forged composite of unsintered hydroxyapatite and poly-L-lactide (F-u-HA/PLLA). Materials and Methods From January 2006 to June 2010, 29 patients (24 males and 5 females; age 33 ± 15 years) were included in the present prospective study. The fracture type was malar in 24 patients, midfacial in 5, isolated orbital floor blowout in 2, and frontal sinus, cranial base in 2 patients. The fractures were fixed with internal fixation devices; these were plates and screws composed of F-u-HA/PLLA. The 24 patients with malar frac…

AdultMaleBiocompatibilityAdolescentRadiographymedicine.medical_treatmentPolyestersDentistryFractures BoneFracture fixationmedicineInternal fixationHumansProspective StudiesBone growthFrontal sinusZygomabusiness.industryUltrasoundMiddle Agedmedicine.diseaseInternal Fixatorsmedicine.anatomical_structureDurapatiteOtorhinolaryngologyFaceSurgeryFemaleOral SurgeryForeign bodybusinessTomography X-Ray ComputedJournal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons
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A pilot study of laparoscopic adhesion prophylaxis after myomectomy with a copolymer designed for endoscopic application.

2009

Abstract Study Objective To assess the laparoscopic handling and safety of D,L-polylactide-e-caprolactone-trimethylene carbonate (PCT) copolymer after myomectomy and compare it with icodextrin. In contrast to previously developed solid barriers, the material has rationally designed properties that are advantageous for convenient laparoscopic application. Design A randomized, single-blinded clinical study (Canadian Task Force Classification I). Setting Single-center study in a German University Hospital. Patients Thirty patients who underwent laparoscopic myomectomy were enrolled. Interventions After laparoscopic myomectomy and subsequent reconstruction of the uterus with interrupted sutures…

Adultmedicine.medical_specialtyRandomizationPolyestersAdhesion (medicine)Pilot ProjectsTissue AdhesionsPeritoneal DiseasesIcodextrinIcodextrinmedicineHumansSingle-Blind MethodAdverse effectLaparoscopyGlucansmedicine.diagnostic_testLeiomyomabusiness.industryPelvic painSuture TechniquesObstetrics and GynecologyAdhesion barriermedicine.diseaseSurgerymedicine.anatomical_structureGlucoseTreatment OutcomeUterine NeoplasmsAbdomenFemaleLaparoscopymedicine.symptombusinessFollow-Up StudiesJournal of minimally invasive gynecology
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Rapid vascularization of starchâ poly(caprolactone) in vivo by outgrowth endothelial cells in co-culture with primary osteoblasts

2011

The successful integration of in vitro-generated tissues is dependent on adequate vascularization in vivo. Human outgrowth endothelial cells (OECs) isolated from the mononuclear cell fraction of peripheral blood represent a potent population of circulating endothelial progenitors that could provide a cell source for rapid anastomosis and scaffold vascularization. Our previous work with these cells in co-culture with primary human osteoblasts has demonstrated their potential to form perfused vascular structures within a starch–poly(caprolactone) biomaterial in vivo. In the present study, we demonstrate the ability of OECs to form perfused vascular structures as early as 48 h following subcut…

AngiogenesisPolyestersPopulationBiomedical EngineeringNeovascularization PhysiologicMedicine (miscellaneous)02 engineering and technologyBiologyBiomaterialsNeovascularization03 medical and health sciencesTissue engineeringIn vivoIn vivomedicineHumansVimentinProgenitor celleducationCells CulturedCell Proliferation030304 developmental biologyPericyte0303 health scienceseducation.field_of_studyOsteoblastsScience & TechnologyOsteoblastEndothelial CellsOutgrowth endothelial cellStarchOsteoblast021001 nanoscience & nanotechnologyImmunohistochemistryCoculture Techniques3. Good healthCell biologyPlatelet Endothelial Cell Adhesion Molecule-1medicine.anatomical_structureBlood VesselsPericyteAngiogenesismedicine.symptomCo-culture0210 nano-technologyBiomedical engineering
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Biomedical Applications of Polylactide (PLA) and Its Copolymers.

2018

n/a

Anti-Infective AgentPolyestersMicrofluidicsPolyesterPharmaceutical ScienceBiocompatible Materials02 engineering and technology01 natural sciencesAnalytical ChemistryPolymerizationlcsh:QD241-441Nanoparticlelcsh:Organic chemistryAnti-Infective AgentsDrug DiscoveryCopolymerHumansPhysical and Theoretical ChemistryDrug CarrierBiocompatible MaterialDrug CarriersPolymer scienceTissue Scaffolds010405 organic chemistryChemistryOrganic Chemistry021001 nanoscience & nanotechnologyBone Diseases Infectious0104 chemical sciencesBone Diseases Infectioun/aEditorialMicrofluidicChemistry (miscellaneous)PeptideMolecular MedicineNanoparticles0210 nano-technologyPeptidesHumanMolecules (Basel, Switzerland)
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Treatment of isolated ascending aortic aneurysm by off-pump epiaortic wrapping is safe and durable.

2016

OBJECTIVES: Isolated ascending aortic aneurysm (iAA) is usually treated by open graft repair requiring sternotomy, cardiopulmonary bypass (CPB) and cardioplegia. This approach carries significant mortality in older patients or those presenting with comorbidities. We report an original series of patients presenting with iAA and treated with epiaortic wrapping by using a synthetic mesh. This less invasive aortic repair technique allows reducing the aortic diameter to a predefined value and is performed without CPB. METHODS: Data from patients presenting with an iAA and treated with the wrapping technique (WT) by polypropylene/polyester mesh from November 2006 to July 2015 were collected. The …

Aortic valveMaleTime Factors030204 cardiovascular system & hematologySettore MED/22 - Chirurgia Vascolarelaw.inventionAortic aneurysm0302 clinical medicinelawAorta10042 Clinic for Diagnostic and Interventional RadiologyMedicine (all)Middle Aged2746 Surgerymedicine.anatomical_structureTreatment OutcomeWrapping girdlingFemaleCardiology and Cardiovascular MedicineVascular Surgical ProceduresPulmonary and Respiratory Medicinemedicine.medical_specialtyOffOff-pump610 Medicine & healthProsthesis Design2705 Cardiology and Cardiovascular MedicineGraft repair03 medical and health sciencesAneurysmBlood vessel prosthesismedicine.arteryAscending aortamedicineCardiopulmonary bypassHumansAortic valve insufficiency; Ascending aorta; Graft repair; Mesh (polypropylene/polyester); Off-pump; Wrapping girdling; Surgery; Medicine (all); Pulmonary and Respiratory Medicine; Cardiology and Cardiovascular MedicineAgedRetrospective StudiesAortaAortic Aneurysm Thoracicbusiness.industryPerioperativemedicine.diseaseSternotomySurgeryBlood Vessel Prosthesis030228 respiratory systemAortic valve insufficiency2740 Pulmonary and Respiratory MedicinepumpSurgeryAscending aortaMesh (polypropylene/polyester)businessFollow-Up StudiesInteractive cardiovascular and thoracic surgery
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NEW GRAFT COPOLYMERS OF HYALURONIC ACID AND POLYLACTIC ACID: SYNTHESIS AND CHARACTERIZATION

2006

Abstract New graft copolymers have been synthesized, using hyaluronic acid (HA) as a hydrophilic backbone and polylactic acid (PLA) as an aliphatic polyester in order to obtain new polymeric derivatives of HA able to hydrophobically associate in an aqueous medium. Hyaluronic acid with low molecular weight was made soluble in organic solvent by transformation to its tetrabutylammonium (TBA) salt. Using the HA–TBA derivative, the reaction was performed in dimethylsulfoxide adding as a reagent the N -hydroxysuccinimide derivative of PLA. Two HA–PLA graft copolymers have been synthesized and characterized by FT-IR, 1 H NMR spectroscopy and gel permeation chromatography. The interaction between …

Aqueous solutionPolymers and PlasticsOrganic ChemistryChemical modificationhyaluronic acid self assemblyPolyelectrolytePolyesterHydrophobic effectGel permeation chromatographychemistry.chemical_compoundPolylactic acidchemistryPolymer chemistryMaterials ChemistryCopolymer
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Effect of Graphene Nanoplatelets on the Physical and Antimicrobial Properties of Biopolymer-Based Nanocomposites

2016

In this work, biopolymer-based nanocomposites with antimicrobial properties were prepared via melt-compounding. In particular, graphene nanoplatelets (GnPs) as fillers and an antibiotic, i.e., ciprofloxacin (CFX), as biocide were incorporated in a commercial biodegradable polymer blend of poly(lactic acid) (PLA) and a copolyester (BioFlex®). The prepared materials were characterized by scanning electron microscopy (SEM), and rheological and mechanical measurements. Moreover, the effect of GnPs on the antimicrobial properties and release kinetics of CFX was evaluated. The results indicated that the incorporation of GnPs increased the stiffness of the biopolymeric matrix and allowed for the t…

BiocideMaterials scienceScanning electron microscopeKineticsAntimicrobial activity; Ciprofloxacin; Drug release; Graphene nanoplatelets (GnPs); Nanocomposites; Poly(lactic acid) (PLA); Materials Science (all)02 engineering and technologyengineering.material010402 general chemistry01 natural scienceslcsh:TechnologyArticlepoly(lactic acid) (PLA)ciprofloxacinnanocompositesGeneral Materials ScienceComposite materiallcsh:Microscopydrug releaselcsh:QC120-168.85NanocompositeNanocompositeantimicrobial activitylcsh:QH201-278.5lcsh:T021001 nanoscience & nanotechnologyAntimicrobialBiodegradable polymerCopolyestergraphene nanoplatelets (GnPs)0104 chemical sciencesChemical engineeringnanocomposites; graphene nanoplatelets (GnPs); poly(lactic acid) (PLA); antimicrobial activity; drug release; ciprofloxacinlcsh:TA1-2040engineeringlcsh:Descriptive and experimental mechanicsMaterials Science (all)Biopolymerlcsh:Electrical engineering. Electronics. Nuclear engineering0210 nano-technologylcsh:Engineering (General). Civil engineering (General)lcsh:TK1-9971Materials; Volume 9; Issue 5; Pages: 351
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Antimicrobial beeswax coated polylactide films with silver control release capacity.

2013

Although the application of silver based antimicrobial systems is a widespread technology, its implementation in areas such as food packaging is still challenging. The present paper describes the fabrication of poly(lactic acid) (PLA) coated with beeswax with controlled release properties for sustained antimicrobial performance. Release of silver ions from the polymers was monitored voltammetrically under various conditions (surface contact, immersion in various liquid media and at different pH values) throughout at least 7days. A higher release was noted with decreasing pH while surface release was much slower than the release when immersed in liquid medium. While uncoated films demonstrat…

BiocideSilverPolymersPolyestersNanotechnologyMicrobiologyBeeswaxchemistry.chemical_compoundLactic Acidchemistry.chemical_classificationChemistryFood PackagingSalmonella entericaGeneral MedicinePolymerHydrogen-Ion ConcentrationAntimicrobialControlled releaseLactic acidAnti-Bacterial AgentsFood packagingSteamChemical engineeringvisual_artDelayed-Action PreparationsWaxesvisual_art.visual_art_mediumLayer (electronics)Food ScienceInternational journal of food microbiology
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New gellan gum-graft-poly(D,L-lactide-co-glycolide) copolymers as promising bioinks: Synthesis and characterization

2020

This research focused on the aim of tackling the urgent demand of printable biomaterials, hence we synthetized and characterized three gellan gum-graft-poly(d,l-lactide-co-glycolide) copolymers (GGm-PLGA a, b and c) which differed in the graft substitution degree. We investigated the effect of the polyester chain grafted onto hydrophilic backbone of gellan gum in terms of physicochemical properties and the ability of the system to print 3D cell laden constructs. In particular, we evaluated thermo-rheological, ionotropic crosslinking, shear thinning, swelling and stability properties of these copolymers and their derived biomaterials and findings related to the degree of functionalization. M…

Biocompatible Materials02 engineering and technologyBiochemistry03 medical and health scienceschemistry.chemical_compoundMicePolylactic Acid-Polyglycolic Acid CopolymerGraft copolymersStructural BiologyMaterials TestingmedicineCopolymerAnimalsMolecular Biology030304 developmental biologyMechanical Phenomena0303 health sciencesShear thinningTissue EngineeringChemistryPolysaccharides BacterialBioprintingGeneral Medicine3T3 Cells021001 nanoscience & nanotechnologyGellan gumPolyesterChemical engineeringSurface modificationPoly d l lactideInkPoly (DL-lactide-co-glycolide) (PLGA)Swellingmedicine.symptom0210 nano-technologyRheologyGellan gum (GG)
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