{"id":{"repo_id":"aachen","oai_identifier":"oai:publications.rwth-aachen.de:56558"},"canonical_url":"https://search.dev.ndltd.org/etd/aachen/oai:publications.rwth-aachen.de:56558","repository":{"repo_id":"aachen","name":"RWTH Aachen University","base_url":"https://publications.rwth-aachen.de/oai2d"},"display":{"title":"Entwicklung einer biodegradierbaren Harnleiterschiene : In-vitro-Analytik von Poly(D,L-Lactid) als Homo- und Copolymer, Formgebungs-Technologie, Oberflächenmodifizierung und tierexperimentelle Untersuchung im Schaf-Modell","abstract":"With the objective of developing a biodegradable ureteric stent, various polylactides were analyzed and grafted with a clinically adapted surface. Stent moulding was performed by CESP-technology (Controlled Expansion of Saturated Polymers), which is not based on high temperature but gas-loading under high pressure which induces a foamy bulk structure. The hydrolytically biodegradable, synthetic homo- and copolymers poly(D,L-lactide) (PDLLA), poly(D,L-lactide-co-trimethylene-carbonate) (PDLLA-co-TMC), poly(D,L-lactide-co-glycolide) (PDLLA-co-Gly) as derivatives of lactic acid or glycolic acid and surface modifications with hydroxyethylenemethacrylate (HEMA) and oligoethyleneoxidemonomethacrylate (OEOMA) were analyzed with regard to cytotoxicity and cell adhesion. Methacrylates have minimized protein and cell adhesion and degradation of non-toxic products. All polymers exhibited a high degree of biocompatibility and cell adhesion was markedly reduced following HEMA grafting. A 3 cm and 7 Charrière prototype of the stent was moulded from PDLLA-co-TMC by CESP-technology, and grafted with HEMA by means of plasma-induced polymerization. Finally, the stents were implanted into female sheep, following unilateral ureterotomy. Regular blood and urine analysis as well as ultrasound and the final autopsy revealed no pathological findings. Histopathological analysis exhibited a regular epithelium without any changes being determined by contact to the stent, and a good regeneration of all layers in the area of anastomosis.","abstract_html":"With the objective of developing a biodegradable ureteric stent, various polylactides were analyzed and grafted with a clinically adapted surface. Stent moulding was performed by CESP-technology (Controlled Expansion of Saturated Polymers), which is not based on high temperature but gas-loading under high pressure which induces a foamy bulk structure. The hydrolytically biodegradable, synthetic homo- and copolymers poly(D,L-lactide) (PDLLA), poly(D,L-lactide-co-trimethylene-carbonate) (PDLLA-co-TMC), poly(D,L-lactide-co-glycolide) (PDLLA-co-Gly) as derivatives of lactic acid or glycolic acid and surface modifications with hydroxyethylenemethacrylate (HEMA) and oligoethyleneoxidemonomethacrylate (OEOMA) were analyzed with regard to cytotoxicity and cell adhesion. Methacrylates have minimized protein and cell adhesion and degradation of non-toxic products. All polymers exhibited a high degree of biocompatibility and cell adhesion was markedly reduced following HEMA grafting. A 3 cm and 7 Charrière prototype of the stent was moulded from PDLLA-co-TMC by CESP-technology, and grafted with HEMA by means of plasma-induced polymerization. Finally, the stents were implanted into female sheep, following unilateral ureterotomy. Regular blood and urine analysis as well as ultrasound and the final autopsy revealed no pathological findings. Histopathological analysis exhibited a regular epithelium without any changes being determined by contact to the stent, and a good regeneration of all layers in the area of anastomosis.","abstract_has_math":false,"creators":["Hölzl, Friedrich"],"institution":"Publikationsserver der RWTH Aachen University","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Jakse, Gerhard"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2001,"date_issued":"2001","date_published":"2001","updated_at":"2026-07-30T19:41:53Z","subjects":["info:eu-repo/classification/ddc/610","Medizin"],"languages":["ger"],"rights":["info:eu-repo/semantics/openAccess"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-118651%22"],"render_values":[{"text":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-118651%22","href":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-118651%22","code":true}]}]},"links":{"outbound_url":"https://publications.rwth-aachen.de/record/56558","outbound_label":"Repository record","outbound_source":"dc:identifier"},"source_record":{"url":"https://publications.rwth-aachen.de/oai2d?verb=GetRecord&metadataPrefix=oai_dc&identifier=oai%3Apublications.rwth-aachen.de%3A56558","prefix":"oai_dc"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Jakse, Gerhard"]},{"key":"dc:creator","label":"Author","values":["Hölzl, Friedrich"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:coverage","label":"Dc Coverage","values":["DE"]},{"key":"dc:date","label":"Dc Date","values":["2001"]},{"key":"dc:publisher","label":"Institution","values":["Publikationsserver der RWTH Aachen University"]},{"key":"dc:relation","label":"Dc Relation","values":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-1730"]},{"key":"dc:type","label":"Dc Type","values":["info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["info:eu-repo/classification/ddc/610","Medizin"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["ger"]},{"key":"dc:rights","label":"Dc Rights","values":["info:eu-repo/semantics/openAccess"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/record/56558","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-118651%22"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["With the objective of developing a biodegradable ureteric stent, various polylactides were analyzed and grafted with a clinically adapted surface. Stent moulding was performed by CESP-technology (Controlled Expansion of Saturated Polymers), which is not based on high temperature but gas-loading under high pressure which induces a foamy bulk structure. The hydrolytically biodegradable, synthetic homo- and copolymers poly(D,L-lactide) (PDLLA), poly(D,L-lactide-co-trimethylene-carbonate) (PDLLA-co-TMC), poly(D,L-lactide-co-glycolide) (PDLLA-co-Gly) as derivatives of lactic acid or glycolic acid and surface modifications with hydroxyethylenemethacrylate (HEMA) and oligoethyleneoxidemonomethacrylate (OEOMA) were analyzed with regard to cytotoxicity and cell adhesion. Methacrylates have minimized protein and cell adhesion and degradation of non-toxic products. All polymers exhibited a high degree of biocompatibility and cell adhesion was markedly reduced following HEMA grafting. A 3 cm and 7 Charrière prototype of the stent was moulded from PDLLA-co-TMC by CESP-technology, and grafted with HEMA by means of plasma-induced polymerization. Finally, the stents were implanted into female sheep, following unilateral ureterotomy. Regular blood and urine analysis as well as ultrasound and the final autopsy revealed no pathological findings. Histopathological analysis exhibited a regular epithelium without any changes being determined by contact to the stent, and a good regeneration of all layers in the area of anastomosis."]},{"key":"dc:source","label":"Dc Source","values":["Aachen : Publikationsserver der RWTH Aachen University II, 81 S. : Ill., graph. Darst. (2001). = Aachen, Techn. Hochsch., Diss., 2001"]},{"key":"dc:title","label":"Title","values":["Entwicklung einer biodegradierbaren Harnleiterschiene : In-vitro-Analytik von Poly(D,L-Lactid) als Homo- und Copolymer, Formgebungs-Technologie, Oberflächenmodifizierung und tierexperimentelle Untersuchung im Schaf-Modell"]}]}],"canonical_facts":{"dc:contributor":["Jakse, Gerhard"],"dc:coverage":["DE"],"dc:creator":["Hölzl, Friedrich"],"dc:date":["2001"],"dc:description":["With the objective of developing a biodegradable ureteric stent, various polylactides were analyzed and grafted with a clinically adapted surface. Stent moulding was performed by CESP-technology (Controlled Expansion of Saturated Polymers), which is not based on high temperature but gas-loading under high pressure which induces a foamy bulk structure. The hydrolytically biodegradable, synthetic homo- and copolymers poly(D,L-lactide) (PDLLA), poly(D,L-lactide-co-trimethylene-carbonate) (PDLLA-co-TMC), poly(D,L-lactide-co-glycolide) (PDLLA-co-Gly) as derivatives of lactic acid or glycolic acid and surface modifications with hydroxyethylenemethacrylate (HEMA) and oligoethyleneoxidemonomethacrylate (OEOMA) were analyzed with regard to cytotoxicity and cell adhesion. Methacrylates have minimized protein and cell adhesion and degradation of non-toxic products. All polymers exhibited a high degree of biocompatibility and cell adhesion was markedly reduced following HEMA grafting. A 3 cm and 7 Charrière prototype of the stent was moulded from PDLLA-co-TMC by CESP-technology, and grafted with HEMA by means of plasma-induced polymerization. Finally, the stents were implanted into female sheep, following unilateral ureterotomy. Regular blood and urine analysis as well as ultrasound and the final autopsy revealed no pathological findings. Histopathological analysis exhibited a regular epithelium without any changes being determined by contact to the stent, and a good regeneration of all layers in the area of anastomosis."],"dc:identifier":["https://publications.rwth-aachen.de/record/56558","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-118651%22"],"dc:language":["ger"],"dc:publisher":["Publikationsserver der RWTH Aachen University"],"dc:relation":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-1730"],"dc:rights":["info:eu-repo/semantics/openAccess"],"dc:source":["Aachen : Publikationsserver der RWTH Aachen University II, 81 S. : Ill., graph. Darst. (2001). = Aachen, Techn. Hochsch., Diss., 2001"],"dc:subject":["info:eu-repo/classification/ddc/610","Medizin"],"dc:title":["Entwicklung einer biodegradierbaren Harnleiterschiene : In-vitro-Analytik von Poly(D,L-Lactid) als Homo- und Copolymer, Formgebungs-Technologie, Oberflächenmodifizierung und tierexperimentelle Untersuchung im Schaf-Modell"],"dc:type":["info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]},"updated_at":"2026-07-30T19:41:53Z"}