Zielgerichtete Chemotherapie solider Tumoren durch thermosensitive Liposomen in Kombination mit Doxorubicin, Gemcitabin und Mitomycin C

Auf DPPG2 basierende thermosensitive Liposomen (TSL) mit Hyperthermie (HT) induzierter zielgerichteter Wirkstofffreisetzung sind eine viel-versprechende Behandlungsstrategie in der Krebstherapie. TSL können als Wirkstoffträgersysteme die Zirkulationszeit und Anreicherung von Wirkstoffen im Zielgewebe erhöhen. Die vielfältigen Krebserkrankungen zeigen unterschiedliches Tumoransprechen auf die routinemäßig eingesetzten Zytostatika. Daher wäre es vorteilhaft, verschiedene Wirkstoffe in TSL einschließen zu können, um Erstlinientherapien weiter zu verbessern. In dieser Arbeit wurden Mitomycin C (Mito) und Gemcitabin (Gem) erstmals in TSL eingeschlossen. Außerdem wurden sie in vitro und in vivo charakterisiert. Die bereits untersuchten TSL(Dox) sollten ihre Vorzüge in einem in dieser Arbeit neuentwickelten orthotopen Blasenkarzinom-Model der Ratte demonstrieren. In Pharmakokinetikstudien wurde die Stabilität der TSL-Formulierungen getestet, die Dosisabhängigkeit untersucht und die Plasmahalbwertszeiten bei wiederholten Injektionen miteinander verglichen. Außerdem wurde eine neue Methode für die Tumorgenerierung und HT-Behandlung in der Rattenblase etabliert. Anschließend wurde die Gewebeverteilung und Tumoranreicherung in der Blase nach Behandlung mit TSL(Dox) +HT untersucht. Die Ergebnisse wurden mit denen der intravesikalen Therapie verglichen. Zusätzlich wurde die Therapieeffizienz von TSL(Gem) im subkutanen Weichteilsarkom untersucht. Die Liposomen wurden durch die Lipidfilmhydratisierungs- und Extrusionsmethode hergestellt und aktiv oder passiv mit Wirkstoff beladen. Die TSL wurden mit Hilfe von dynamischer Lichtstreuung, Dünnschicht-chromatographie, Phosphatbestimmung, Fluoreszenzspektroskopie und HPLC-Analyse charakterisiert. In vivo-Experimente wurden unter Inhalationsnarkose in weiblichen F344 Ratten und männlichen Brown Norway Ratten, durchgeführt. Die HT-Behandlung wurde durch Erwärmung mit Licht oder Wasserbad im Weichteilsarkom-Modell oder einer Blasenspülung mit warmen Wasser im Blasenkarzinom-Modell durchgeführt. TSL(Mito) wiesen eine niedrige Einschlusseffizienz auf und waren in vitro und in vivo sehr instabil. TSL(Gem) und TSL(Dox) hingegen zeigten bei Körpertemperatur eine lange Zirkulationszeit nach intravenöser (i.v.) Verabreichung. TSL(Dox) zeigten bei höherer Verabreichungsdosis eine verlängerte Zirkulationszeit. Wiederholte Injektionen mit TSL(Dox) nach 7 oder 14 Tagen, beeinflussten die Pharmakokinetik des Wirkstoffes nicht. Durch chemische Vorbehandlung der Blase und anschließende Tumorzell-instillation wurde Tumorwachstum in der Blase erzeugt, das nach spätestens 5 Tagen zystoskopisch erkennbar war. Mit kontinuierlicher Spülung mit warmer Flüssigkeit konnte die Blase problemlos für die Behandlungsdauer von 1 h auf 41 °C erwärmt werden. Das Vorhandensein eines Tumors reduzierte die Dox-Aufnahme in die Blasenwand. Bei intravesikaler Therapie mit nicht liposomalem Dox wurden im Urothel bzw. der Tunica muscularis nur 78% bzw. 45% der Konzentration erreicht, die bei systemischen Injektion mit TSL(Dox) +HT erreicht wurde. Die Therapie des Weichteilsarkoms mit Gem zeigte den Vorteil des liposomalen Einschlusses von Gem im Vergleich zum freien Wirkstoff. TSL(Gem) -HT zeigte eine geringfügigere Tumorwachstumsverzögerung verglichen mit freiem Gem ±HT. Die HT induzierte Wirkstofffreisetzung zeigte eine signifikante stärkere Inhibierung des Tumorwachstums verglichen mit allen anderen Gruppen. Die Resultate zeigen, dass nicht alle Wirkstoffe für den Einschluss in auf DPPG2 basierende Liposomen geeignet sind. Die Pharmakokinetik wird bei wiederholter Applikation nicht durch verstärkten Liposomenabbau beeinflusst. TSL und HT zeigten Vorteile in der Anreicherung und Therapie in verschiedenen Tumormodellen. TSL in Kombination mit HT sind eine wertvolle Errungenschaft für die Krebstherapie und sollten weiter untersucht werden.Targeted chemotherapy in solid tumors with thermosensitive liposomes in combination with doxorubicin, gemcitabine and mitomycin C DPPG2-based thermosensitive liposomes (TSL) in combination with local hyperthermia (HT) induced targeted drug delivery are a promising treatment strategy in anticancer therapy. TSL, as a drug carrier system, can improve circulation half-life and accumulation of drugs in target tissue. The variety of cancer types show different therapy response to commonly used cytostatic agents. Therefore it would be advantageous to encapsulate different cytotoxic drugs into TSL for enhanced first line treatment. In this thesis mitomycin C (Mito) and gemcitabine (Gem) were newly encapsulated into TSL and were characterized in vivo and in vitro. The well tested TSL(Dox) were used to show superior in vivo properties compared to free drug in an novel orthotopic rat bladder cancer tumor model. Pharmakokinetic studies were performed to investigate the TSL formulations for stability, to evaluate dose dependency and to compare plasma half-life after repeated injection. Furthermore a new method for rat bladder tumor growth and hyperthermia treatment was developed. The aim was to show tissue distribution and bladder tumor accumulation after the treatment with TSL(Dox) and HT. The results were compared to those of a treatment with intravesical chemotherapy. TSL(Gem) were evaluated for antitumor activity in a subcutaneously growing soft tissue sarcoma model. Liposomes were prepared by the lipid film hydration and extrusion method, followed by active or passive drug loading. TSL were characterized by dynamic light scattering, thin layer chromatography, phosphate assay, fluorescence spectroscopy and HPLC. In vivo-experiments were performed under inhalation anesthesia in female F344 and male Brown Norway rats. HT treatment was performed by light exposure or warm rinse water. For TSL(Mito) low encapsulation efficacy and poor in vitro and in vivo stability even at low temperatures was found. TSL(Gem) and TSL(Dox) showed long circulation half-lifes at body temperature after intravenous (i.v.) injection. For TSL(Dox) an increase in circulation time was observed at higher dose. A repeated injection of TSL(Dox) after 7 or 14 days did not influence pharmacokinetic parameter of the drug. Chemical preconditioning of the bladder and following tumor cell instillation generated bladder tumor growth observable by cystoscopy at least after 5 days. A continuous warm liquid flow was feasible to heat the bladder to 41 °C, for the treatment period of 1 h. Tumor appearance in the bladder is combined with a decrease in Dox uptake into the bladder wall. Intravesical therapy with non-liposomal Dox reached in the urothelium and the muscle layer only 78% and 45% of the concentration achieved with i.v. injected TSL(Dox) +HT, respectively. The therapeutic study with Gem in the rat soft tissue sarcoma demonstrated advantages for liposomal encapsulation over application of free drug. TSL(Gem) -HT showed only small retardation in tumor growth delay over non liposomal Gem ±HT. HT triggered drug release showed significant increase in tumor growth inhibition compared to all other groups. The results show that there is a possibility for successful encapsulation of different drugs into TSL, but not all drugs are suitable. Pharmacokinetic was not influenced by faster degradation after repeated injections. TSL +HT showed advantages in accumulation and therapy in different tumor models. TSL in combination with HT are a feasible tool in cancer therapy and should further be evaluated

A Heat‐Activated Drug‐Delivery Platform Based on Phosphatidyl‐(oligo)‐glycerol Nanocarrier for Effective Cancer Treatment

The potential of cancer drugs is not fully exploited due to low tumor uptake and occurrence of systemic side effects, limiting maximum tolerated dose. Actively targeted nanocarriers improve efficacy while minimizing off‐target toxicity. Herein, it is the first time a drug‐delivery platform for heat‐triggered intravascular drug release is described, based on synthetic phosphatidyl‐(oligo)‐glycerols from organic synthesis to preclinical investigation in feline patients. For the nanocarrier formulated doxorubicin (DOX), superior tumor drug delivery and antitumor activity compared with free DOX, conventional liposomal DOX (Caelyx), and temperature‐sensitive lysolipid‐containing DOX‐liposomes in rat sarcoma are demonstrated. In a comparative oncological study with neoadjuvant treatment of feline sarcoma, a metabolic response determined with 18 F‐FDG‐positron emission tomography/magnetic resonance imaging (PET/MRI) and histopathological response after tumor resection are significantly better compared with free DOX, potentially by overcoming drug resistance based on improved intratumoral drug distribution. This novel drug‐delivery platform has great potential for the treatment of locally advanced tumors in humans

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Patients with SARS-CoV-2-Induced Viral Sepsis Simultaneously Show Immune Activation, Impaired Immune Function and a Procoagulatory Disease State

Background: It is widely accepted that SARS-CoV-2 causes a dysregulation of immune and coagulation processes. In severely affected patients, viral sepsis may result in life endangering multiple organ dysfunction. Furthermore, most therapies for COVID-19 patients target either the immune system or coagulation processes. As the exact mechanism causing SARS-CoV-2-induced morbidity and mortality was unknown, we started an in-depth analysis of immunologic and coagulation processes. Methods: 127 COVID-19 patients were treated at the University Hospital Essen, Germany, between May 2020 and February 2022. Patients were divided according to their maximum COVID-19 WHO ordinal severity score (WHO 0–10) into hospitalized patients with a non-severe course of disease (WHO 4–5, n = 52) and those with a severe course of disease (WHO 6–10, n = 75). Non-infected individuals served as healthy controls (WHO 0, n = 42). Blood was analyzed with respect to cell numbers, clotting factors, as well as pro- and anti-inflammatory mediators in plasma. As functional parameters, phagocytosis and inflammatory responses to LPS and antigen-specific stimulation were determined in monocytes, granulocytes, and T cells using flow cytometry. Findings: In the present study, immune and coagulation systems were analyzed simultaneously. Interestingly, many severe COVID-19 patients showed an upregulation of pro-inflammatory mediators and at the same time clear signs of immunosuppression. Furthermore, severe COVID-19 patients not only exhibited a disturbed immune system, but in addition showed a pronounced pro-coagulation phenotype with impaired fibrinolysis. Therefore, our study adds another puzzle piece to the already complex picture of COVID-19 pathology implying that therapies in COVID-19 must be individualized. Conclusion: Despite years of research, COVID-19 has not been understood completely and still no therapies exist, fitting all requirements and phases of COVID-19 disease. This observation is highly reminiscent to sepsis. Research in sepsis has been going on for decades, while the disease is still not completely understood and therapies fitting all patients are lacking as well. In both septic and COVID-19 patients, immune activation can be accompanied by immune paralysis, complicating therapeutic intervention. Accordingly, therapies that lower immune activation may cause detrimental effects in patients, who are immune paralyzed by viral infections or sepsis. We therefore suggest individualizing therapies and to broaden the spectrum of immunological parameters analyzed before therapy. Only if the immune status of a patient is understood, can a therapeutic intervention be successful