{"id":{"repo_id":"aachen","oai_identifier":"oai:publications.rwth-aachen.de:59422"},"canonical_url":"https://search.dev.ndltd.org/etd/aachen/oai:publications.rwth-aachen.de:59422","repository":{"repo_id":"aachen","name":"RWTH Aachen University","base_url":"https://publications.rwth-aachen.de/oai2d"},"display":{"title":"Untersuchungen zur Gefriertrocknung biologischer Zellen am Beispiel menschlicher Erythrozyten","abstract":"Freeze-drying is a state of the art process for stabilization of pharmaceutical or biotechnological products. However, a successful preservation of living cells by freeze-drying is still a big challenge. This is mainly due to increased requirements on the product quality, since even smallest structural changes of the complex cell morphology can lead to a loss of function or viability. Using human erythrocytes as a simple model for biological cells in general, several mechanisms were investigated presumed to be responsible for cell damage during the freeze-drying process. Besides a considerable progress in understanding of these mechanisms, the cell recovery rate could gradually be increased from about 0% to 50% by means of following major developments and studies. A new low-temperature freeze-drying device was designed and manufactured that allows a controlled cooling of condenser and shelf down to >190°C and >80°C, respectively. A variation of shelf temperature and drying time led to optimized vacuum-drying conditions. The temperature inside the sample, which was either measured or calculated, was found to be a key quantity for the resulting cell damage. A cooling rate variation showed that ultra rapid cooling with a rate of up to 13.500 K/min leads to amorphous sample structures providing best cell protection during subsequent drying.","abstract_html":"Freeze-drying is a state of the art process for stabilization of pharmaceutical or biotechnological products. However, a successful preservation of living cells by freeze-drying is still a big challenge. This is mainly due to increased requirements on the product quality, since even smallest structural changes of the complex cell morphology can lead to a loss of function or viability. Using human erythrocytes as a simple model for biological cells in general, several mechanisms were investigated presumed to be responsible for cell damage during the freeze-drying process. Besides a considerable progress in understanding of these mechanisms, the cell recovery rate could gradually be increased from about 0% to 50% by means of following major developments and studies. A new low-temperature freeze-drying device was designed and manufactured that allows a controlled cooling of condenser and shelf down to >190°C and >80°C, respectively. A variation of shelf temperature and drying time led to optimized vacuum-drying conditions. The temperature inside the sample, which was either measured or calculated, was found to be a key quantity for the resulting cell damage. A cooling rate variation showed that ultra rapid cooling with a rate of up to 13.500 K/min leads to amorphous sample structures providing best cell protection during subsequent drying.","abstract_has_math":false,"creators":["Rindler, Volker"],"institution":"Publikationsserver der RWTH Aachen University","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Rau, Günter"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2000,"date_issued":"2000","date_published":"2000","updated_at":"2026-07-30T19:42:39Z","subjects":["info:eu-repo/classification/ddc/660","Technische Chemie","Erythrozyt","Gefriertrocknung","Prozessoptimierung","Gefrieranlage","Technikumsanlage"],"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-121209%22"],"render_values":[{"text":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121209%22","href":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121209%22","code":true}]}]},"links":{"outbound_url":"https://publications.rwth-aachen.de/record/59422","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Rau, Günter"]},{"key":"dc:creator","label":"Author","values":["Rindler, Volker"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:coverage","label":"Dc Coverage","values":["DE"]},{"key":"dc:date","label":"Dc Date","values":["2000"]},{"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-725"]},{"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/660","Technische Chemie","Erythrozyt","Gefriertrocknung","Prozessoptimierung","Gefrieranlage","Technikumsanlage"]}]},{"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/59422","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121209%22"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Freeze-drying is a state of the art process for stabilization of pharmaceutical or biotechnological products. 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The temperature inside the sample, which was either measured or calculated, was found to be a key quantity for the resulting cell damage. A cooling rate variation showed that ultra rapid cooling with a rate of up to 13.500 K/min leads to amorphous sample structures providing best cell protection during subsequent drying."]},{"key":"dc:source","label":"Dc Source","values":["Aachen : Publikationsserver der RWTH Aachen University 116, XI S. : Ill., graph. Darst. (2000). = Aachen, Techn. Hochsch., Diss., 2000"]},{"key":"dc:title","label":"Title","values":["Untersuchungen zur Gefriertrocknung biologischer Zellen am Beispiel menschlicher Erythrozyten"]}]}],"canonical_facts":{"dc:contributor":["Rau, Günter"],"dc:coverage":["DE"],"dc:creator":["Rindler, Volker"],"dc:date":["2000"],"dc:description":["Freeze-drying is a state of the art process for stabilization of pharmaceutical or biotechnological products. 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