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Dive into the research topics where C. Alexiou is active.

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Featured researches published by C. Alexiou.


Journal of Magnetism and Magnetic Materials | 2002

Magnetic drug targeting: biodistribution and dependency on magnetic field strength ☆

C. Alexiou; A. Schmidt; R. Klein; Peter Hulin; Ch. Bergemann; Wolfgang Arnold

Abstract “Magnetic drug targeting,” a model of locoregional chemotherapy showed encouraging results in treatment of VX2-squamous cell carcinoma in rabbits. In the present study we investigated the biokinetic behavior of Iod[123]-labelled ferrofluids in vivo and showed in vitro that the ferrofluid concentration is dependent on the magnetic field strength.


Hno | 2005

[Magnetic Drug Targeting--a new approach in locoregional tumor therapy with chemotherapeutic agents. Experimental animal studies].

C. Alexiou; Roland Jurgons; Roswitha J. Schmid; Wolf Erhardt; F. Parak; C. Bergemann; Heinrich Iro

ZusammenfassungHintergrundFortgeschrittene bzw. inoperable Plattenepithelkarzinome im Kopf-Hals-Bereich werden vielfach mit einer kombinierten Radio-/Chemotherapie behandelt. Die Strahlentherapie ist gezielt auf das Tumorareal möglich, da gesunde Gewebe von der Strahlung abgeschirmt werden können. Die Chemotherapie hingegen wird in der Regel systemisch appliziert, und die Nebenwirkungen bleiben nicht auf das Zielgewebe begrenzt.Methoden/ArbeitsergebnisseTierexperimentell wurde Magnetisches Drug Targeting zur zielgerichteten und lokalen Chemotherapie untersucht. Hierbei werden Ferrofluide (kolloidale Lösung magnetischer Partikel), an die ein Chemotherapeutikum reversibel gebunden ist, intraarteriell appliziert und mit Hilfe eines externen magnetischen Feldes in einem bestimmten Körperkompartiment (d.xa0h. Tumor) angereichert. Durch diese Applikationsform konnte mit 20 bzw. 50% der üblichen systemischen Chemotherapeutikadosierung eine um bis zu 26-mal höhere Konzentration in der Tumorregion im Vergleich zur herkömmlichen systemischen Gabe (100%) erzielt werden.FazitMagnetisches Drug Targeting stellt einen vielversprechenden Ansatz in der lokoregionären Chemotherapie von Tumoren dar.AbstractBackgroundAdvanced squamous cell carcinomas of the head and neck region were often treated with combined radio-chemotherapy. Radiotherapy allows a focused treatment of the tumor, and healthy tissue can be protected from radiation. Chemotherapy, however, is mostly given systemically and the unwanted negative side effects also develop in many other organs.Aim of the studyLocoregional application of chemotherapeutic agents with Magnetic Drug Targeting on an animal experimental study.Methods and resultsMagnetic Drug Targeting is a new approach to the locoregional treatment of tumors. Ferrofluids (colloidal dispersion of magnetic nanoparticles) were reversibly bound to chemotherapeutic agents and injected intra-arterially, while focused with an external magnetic field to a certain body compartment (i.e. the tumor). With only 20% or 50% percent of the regular systemic chemotherapeutic dose, we achieved an up to 26 times higher concentration in the tumor region with this application compared to the usual systemic administration.ConclusionMagnetic Drug Targeting offers an unique opportunity to treat tumors locoregionally with chemotherapeutic agents.


Hno | 2005

Magnetisches Drug Targeting—ein neuer Ansatz in der lokoregionären Tumortherapie mit Chemotherapeutika

C. Alexiou; Roland Jurgons; Roswitha J. Schmid; Wolf Erhardt; F. Parak; C. Bergemann; Heinrich Iro

ZusammenfassungHintergrundFortgeschrittene bzw. inoperable Plattenepithelkarzinome im Kopf-Hals-Bereich werden vielfach mit einer kombinierten Radio-/Chemotherapie behandelt. Die Strahlentherapie ist gezielt auf das Tumorareal möglich, da gesunde Gewebe von der Strahlung abgeschirmt werden können. Die Chemotherapie hingegen wird in der Regel systemisch appliziert, und die Nebenwirkungen bleiben nicht auf das Zielgewebe begrenzt.Methoden/ArbeitsergebnisseTierexperimentell wurde Magnetisches Drug Targeting zur zielgerichteten und lokalen Chemotherapie untersucht. Hierbei werden Ferrofluide (kolloidale Lösung magnetischer Partikel), an die ein Chemotherapeutikum reversibel gebunden ist, intraarteriell appliziert und mit Hilfe eines externen magnetischen Feldes in einem bestimmten Körperkompartiment (d.xa0h. Tumor) angereichert. Durch diese Applikationsform konnte mit 20 bzw. 50% der üblichen systemischen Chemotherapeutikadosierung eine um bis zu 26-mal höhere Konzentration in der Tumorregion im Vergleich zur herkömmlichen systemischen Gabe (100%) erzielt werden.FazitMagnetisches Drug Targeting stellt einen vielversprechenden Ansatz in der lokoregionären Chemotherapie von Tumoren dar.AbstractBackgroundAdvanced squamous cell carcinomas of the head and neck region were often treated with combined radio-chemotherapy. Radiotherapy allows a focused treatment of the tumor, and healthy tissue can be protected from radiation. Chemotherapy, however, is mostly given systemically and the unwanted negative side effects also develop in many other organs.Aim of the studyLocoregional application of chemotherapeutic agents with Magnetic Drug Targeting on an animal experimental study.Methods and resultsMagnetic Drug Targeting is a new approach to the locoregional treatment of tumors. Ferrofluids (colloidal dispersion of magnetic nanoparticles) were reversibly bound to chemotherapeutic agents and injected intra-arterially, while focused with an external magnetic field to a certain body compartment (i.e. the tumor). With only 20% or 50% percent of the regular systemic chemotherapeutic dose, we achieved an up to 26 times higher concentration in the tumor region with this application compared to the usual systemic administration.ConclusionMagnetic Drug Targeting offers an unique opportunity to treat tumors locoregionally with chemotherapeutic agents.


Physics in Medicine and Biology | 2009

Magnetorelaxometric quantification of magnetic nanoparticles in an artery model after ex vivo magnetic drug targeting

Heike Richter; Frank Wiekhorst; K. Schwarz; S Lyer; R Tietze; C. Alexiou; Lutz Trahms

In magnetic drug targeting a chemotherapeutic agent is bound to coated magnetic nanoparticles, which are administered to the blood vessel system and subsequently focused by an external applied magnetic field. The optimization of intra-arterial magnetic drug targeting (MDT) requires detailed knowledge about the biodistribution of particles in the artery and the respective surrounding after the application. Here, we demonstrate the potential of magnetorelaxometry for quantifying the distribution of magnetic nanoparticles in the artery. To this end, we present a magnetorelaxometry investigation of a MDT study in an artery model. In particular, the absolute magnetic nanoparticle accumulation along the artery as well as the uptake profile along the region around the MDT-magnet position was quantified.


Archive | 2002

Targeted Tumor Therapy with “Magnetic Drug Targeting”: Therapeutic Efficacy of Ferrofluid Bound Mitoxantrone

C. Alexiou; R. Schmid; Roland Jurgons; Ch. Bergemann; Wolfgang Arnold; F.G. Parak

The difference between success or failure of chemotherapy depends not only on the drug itself but also on how it is delivered to its target. Biocompatible ferrofluids (FF) are paramagnetic nanoparticles, that may be used as a delivery system for anticancer agents in locoregional tumor therapy, called “magnetic drug targeting”. Bound to medical drugs, such magnetic nanoparticles can be enriched in a desired body compartment (tumor) using an external magnetic field, which is focused on the area of the tumor. Through this form of target directed drug application, one attempts to concentrate a pharmacological agent at its site of action in order to minimize unwanted side effects in the organism and to increase its locoregional effectiveness.


Hno | 2009

Dislokation von Stimmprothesen

S. Birk; P. Michaeli; M. Kapsreiter; C. Alexiou

Tracheoesophageal voice prostheses after total laryngectomy are infrequently the cause of severe complications. We report on a patient with threefold dislocation of a Provox prosthesis, each with suspected oesophageal loss. The patient came to our hospital with acute dyspnoea. An urgent bronchoscopy showed two prostheses in the right and one in the left main bronchus, which had caused inflammation with extensive occlusion of the bronchus. All three prostheses could be recovered.ZusammenfassungÖsophagotracheale Shuntkanülen nach totaler Laryngektomie sind nur selten Ursache schwerwiegender Komplikationen. Wir berichten über einen Patienten mit 3-facher Dislokation einer Provox®-Prothese und jeweils vermutetem ösophagealem Abgang. Bei akuter Dyspnoe wurde der Patient in unserer Klinik vorgestellt, und eine eilige Bronchoskopie zeigte 2xa0Prothesen im rechten sowie eine im linken Hauptbronchus, die bereits zu deutlichen entzündlichen Veränderungen mit weitgehendem Verschluss geführt hatten. Alle 3xa0Prothesen konnten geborgen werden.AbstractTracheoesophageal voice prostheses after total laryngectomy are infrequently the cause of severe complications. We report on a patient with threefold dislocation of a Provox® prosthesis, each with suspected oesophageal loss. The patient came to our hospital with acute dyspnoea. An urgent bronchoscopy showed two prostheses in the right and one in the left main bronchus, which had caused inflammation with extensive occlusion of the bronchus. All three prostheses could be recovered.


Hno | 2008

Recurrent and metastasizing atypical fibroxanthoma

Michael O. Koch; A. Dimmler; C. Alexiou

ZusammenfassungDas atypische Fibroxanthom ist ein seltener Hauttumor, der vor allem auf sonnenexponierter Haut auftritt. Obwohl er als gutartiger Tumor bezeichnet wird, treten vereinzelt Metastasen auf. Die exakte Einordnung von solchen agressiveren Verläufen des atypischen Fibroxanthoms ist derzeit noch Gegenstand der Diskussion. Präsentiert wird der Fall eines 81-jährigen Patienten mit rezidivierendem atypischem Fibroxanthom im Bereich der rechten Ohrmuschel. Beim zweiten Rezidiv trat gleichzeitig eine solitäre Metastase in der Glandula parotidea rechts auf. Es erfolgte schließlich die komplette Tumorentfernung, die postoperativ indizierte Radiotherapie wurde vom Patienten abgelehnt. Der Patient ist seit 60xa0Monaten rezidivfrei. Die Tumorentität „atypisches Fibroxanthom“ und die entsprechende Therapie werden anhand dieses Beispiels beschrieben und die neuesten Erkenntnisse zu dieser Erkrankung mittels der aktuellen Literatur diskutiert.SummaryAtypical fibroxanthoma is a rare skin tumor that arises particularly on sun-exposed skin. Although it is considered to be a benign tumor, rarely, metastases arise. The accurate classification of aggressive processes of atypical fibroxanthoma is currently still the subject of discussion. The case of an 81-year-old patient with relapsing atypical fibroxanthoma of the right auricle is presented. With the second relapse, a single metastasis in the right parotid gland was detected. A complete tumor excision was performed, and the patient declined the recommended postoperative radiotherapy. The patient has not show any signs of relapse for 60xa0months now. Atypical fibroxanthoma and the appropriate therapy for it are described, and the newest discoveries regarding this disease are discussed on the basis of the current literature.Atypical fibroxanthoma is a rare skin tumor that arises particularly on sun-exposed skin. Although it is considered to be a benign tumor, rarely, metastases arise. The accurate classification of aggressive processes of atypical fibroxanthoma is currently still the subject of discussion. The case of an 81-year-old patient with relapsing atypical fibroxanthoma of the right auricle is presented. With the second relapse, a single metastasis in the right parotid gland was detected. A complete tumor excision was performed, and the patient declined the recommended postoperative radiotherapy. The patient has not show any signs of relapse for 60 months now. Atypical fibroxanthoma and the appropriate therapy for it are described, and the newest discoveries regarding this disease are discussed on the basis of the current literature.


Hno | 2009

Dislocation of voice prostheses. Interdisciplinary management of diagnostics and treatment

S. Birk; P. Michaeli; M. Kapsreiter; C. Alexiou

Tracheoesophageal voice prostheses after total laryngectomy are infrequently the cause of severe complications. We report on a patient with threefold dislocation of a Provox prosthesis, each with suspected oesophageal loss. The patient came to our hospital with acute dyspnoea. An urgent bronchoscopy showed two prostheses in the right and one in the left main bronchus, which had caused inflammation with extensive occlusion of the bronchus. All three prostheses could be recovered.ZusammenfassungÖsophagotracheale Shuntkanülen nach totaler Laryngektomie sind nur selten Ursache schwerwiegender Komplikationen. Wir berichten über einen Patienten mit 3-facher Dislokation einer Provox®-Prothese und jeweils vermutetem ösophagealem Abgang. Bei akuter Dyspnoe wurde der Patient in unserer Klinik vorgestellt, und eine eilige Bronchoskopie zeigte 2xa0Prothesen im rechten sowie eine im linken Hauptbronchus, die bereits zu deutlichen entzündlichen Veränderungen mit weitgehendem Verschluss geführt hatten. Alle 3xa0Prothesen konnten geborgen werden.AbstractTracheoesophageal voice prostheses after total laryngectomy are infrequently the cause of severe complications. We report on a patient with threefold dislocation of a Provox® prosthesis, each with suspected oesophageal loss. The patient came to our hospital with acute dyspnoea. An urgent bronchoscopy showed two prostheses in the right and one in the left main bronchus, which had caused inflammation with extensive occlusion of the bronchus. All three prostheses could be recovered.


Hno | 2007

Rezidivierendes und metastasierendes atypisches Fibroxanthom

Michael Koch; A. Dimmler; C. Alexiou

ZusammenfassungDas atypische Fibroxanthom ist ein seltener Hauttumor, der vor allem auf sonnenexponierter Haut auftritt. Obwohl er als gutartiger Tumor bezeichnet wird, treten vereinzelt Metastasen auf. Die exakte Einordnung von solchen agressiveren Verläufen des atypischen Fibroxanthoms ist derzeit noch Gegenstand der Diskussion. Präsentiert wird der Fall eines 81-jährigen Patienten mit rezidivierendem atypischem Fibroxanthom im Bereich der rechten Ohrmuschel. Beim zweiten Rezidiv trat gleichzeitig eine solitäre Metastase in der Glandula parotidea rechts auf. Es erfolgte schließlich die komplette Tumorentfernung, die postoperativ indizierte Radiotherapie wurde vom Patienten abgelehnt. Der Patient ist seit 60xa0Monaten rezidivfrei. Die Tumorentität „atypisches Fibroxanthom“ und die entsprechende Therapie werden anhand dieses Beispiels beschrieben und die neuesten Erkenntnisse zu dieser Erkrankung mittels der aktuellen Literatur diskutiert.SummaryAtypical fibroxanthoma is a rare skin tumor that arises particularly on sun-exposed skin. Although it is considered to be a benign tumor, rarely, metastases arise. The accurate classification of aggressive processes of atypical fibroxanthoma is currently still the subject of discussion. The case of an 81-year-old patient with relapsing atypical fibroxanthoma of the right auricle is presented. With the second relapse, a single metastasis in the right parotid gland was detected. A complete tumor excision was performed, and the patient declined the recommended postoperative radiotherapy. The patient has not show any signs of relapse for 60xa0months now. Atypical fibroxanthoma and the appropriate therapy for it are described, and the newest discoveries regarding this disease are discussed on the basis of the current literature.Atypical fibroxanthoma is a rare skin tumor that arises particularly on sun-exposed skin. Although it is considered to be a benign tumor, rarely, metastases arise. The accurate classification of aggressive processes of atypical fibroxanthoma is currently still the subject of discussion. The case of an 81-year-old patient with relapsing atypical fibroxanthoma of the right auricle is presented. With the second relapse, a single metastasis in the right parotid gland was detected. A complete tumor excision was performed, and the patient declined the recommended postoperative radiotherapy. The patient has not show any signs of relapse for 60 months now. Atypical fibroxanthoma and the appropriate therapy for it are described, and the newest discoveries regarding this disease are discussed on the basis of the current literature.


Hno | 2009

Dislokation von Stimmprothesen@@@Dislocation of voice prostheses: Interdisziplinäres Vorgehen bei Diagnostik und Therapie@@@Interdisciplinary management of diagnostics and treatment

S. Birk; P. Michaeli; M. Kapsreiter; C. Alexiou

Tracheoesophageal voice prostheses after total laryngectomy are infrequently the cause of severe complications. We report on a patient with threefold dislocation of a Provox prosthesis, each with suspected oesophageal loss. The patient came to our hospital with acute dyspnoea. An urgent bronchoscopy showed two prostheses in the right and one in the left main bronchus, which had caused inflammation with extensive occlusion of the bronchus. All three prostheses could be recovered.ZusammenfassungÖsophagotracheale Shuntkanülen nach totaler Laryngektomie sind nur selten Ursache schwerwiegender Komplikationen. Wir berichten über einen Patienten mit 3-facher Dislokation einer Provox®-Prothese und jeweils vermutetem ösophagealem Abgang. Bei akuter Dyspnoe wurde der Patient in unserer Klinik vorgestellt, und eine eilige Bronchoskopie zeigte 2xa0Prothesen im rechten sowie eine im linken Hauptbronchus, die bereits zu deutlichen entzündlichen Veränderungen mit weitgehendem Verschluss geführt hatten. Alle 3xa0Prothesen konnten geborgen werden.AbstractTracheoesophageal voice prostheses after total laryngectomy are infrequently the cause of severe complications. We report on a patient with threefold dislocation of a Provox® prosthesis, each with suspected oesophageal loss. The patient came to our hospital with acute dyspnoea. An urgent bronchoscopy showed two prostheses in the right and one in the left main bronchus, which had caused inflammation with extensive occlusion of the bronchus. All three prostheses could be recovered.

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M. Kapsreiter

University of Erlangen-Nuremberg

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P. Michaeli

University of Erlangen-Nuremberg

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Roland Jurgons

University of Erlangen-Nuremberg

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S. Birk

University of Erlangen-Nuremberg

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Heinrich Iro

University of Erlangen-Nuremberg

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Roswitha J. Schmid

University of Erlangen-Nuremberg

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Michael Koch

University of Erlangen-Nuremberg

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R Tietze

University of Erlangen-Nuremberg

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S Lyer

University of Erlangen-Nuremberg

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