Organoids as preclinical models to improve intraperitoneal chemotherapy effectiveness for colorectal cancer patients with peritoneal metastases: Preclinical models to improve HIPEC.

BACKGROUND: Peritoneal metastases (PM), corresponding to tumor implants into the peritoneal cavity, are associated with impaired prognosis and low responsiveness to systemic chemotherapy. A new therapeutic approach has dramatically changed the prognosis of patients with PM from colorectal cancer (CRC), consisting in the association of a complete cytoreductive surgery followed by intraperitoneal chemotherapy associated to hyperthermia (HIPEC). Many drugs have been administered intraperitoneally, but no clear consensus has been approved. Therefore, relevant preclinical models are essentials for the efficient translation of treatments option into affected patients. METHOD: Organoids, the last generation of preclinical models, were used to rationalize and improve intraperitoneal chemotherapy. We tested several cytotoxics, combination, effect of hyperthermia, exposure duration and frequency. RESULTS: Organoids were a representative model of response to chemotherapies used for the treatment of PM from CRC; 460mg/m2 of oxaliplatin being the most efficient cytotoxic treatment. Repeated incubations with oxaliplatin; mimicking cycles of intraperitoneal treatment, resulted in an increased efficacy. CONCLUSION & DISCUSSION: Organoids are relevant models to study the chemosensitivity of peritoneal metastases from CRCs. These models could be used for large scale drug screening strategies or personalized medicine, for colorectal carcinoma but also for PM from other origins.

Parameters for Stable Water-in-Oil Lipiodol Emulsion for Liver Trans-Arterial Chemo-Eembolization.

PURPOSE: Water-in-oil type and stability are important properties for Lipiodol emulsions during conventional trans-arterial chemo-embolization. Our purpose is to evaluate the influence of 3 technical parameters on those properties. MATERIALS AND METHODS: The Lipiodol emulsions have been formulated by repetitive back-and-forth pumping of two 10-ml syringes through a 3-way stopcock. Three parameters were compared: Lipiodol/doxorubicin ratio (2/1 vs. 3/1), doxorubicin concentration (10 vs. 20 mg/ml) and speed of incorporation of doxorubicin in Lipiodol (bolus vs. incremental vs. continuous). The percentage of water-in-oil emulsion obtained and the duration until complete coalescence (stability) for water-in-oil emulsions were, respectively, evaluated with the drop-test and static light scattering technique (Turbiscan). RESULTS: Among the 48 emulsions formulated, 32 emulsions (67%) were water-in-oil. The percentage of water-in-oil emulsions obtained was significantly higher for incremental (94%) and for continuous (100%) injections compared to bolus injection (6%) of doxorubicin. Emulsion type was neither influenced by Lipiodol/doxorubicin ratio nor by doxorubicin concentration. The mean stability of water-in-oil emulsions was 215 ± 257 min. The emulsions stability was significantly longer when formulated using continuous compared to incremental injection (326 ± 309 vs. 96 ± 101 min, p = 0.018) and using 3/1 compared to 2/1 ratio of Lipiodol/doxorubicin (372 ± 276 vs. 47 ± 43 min, p = <0.0001). Stability was not influenced by the doxorubicin concentration. CONCLUSION: The continuous and incremental injections of doxorubicin in the Lipiodol result in highly predictable water-in-oil emulsion type. It also demonstrates a significant increase in stability compared to bolus injection. Higher ratio of Lipiodol/doxorubicin is a critical parameter for emulsion stability too.

Stabilization Improves Theranostic Properties of Lipiodol®-Based Emulsion During Liver Trans-arterial Chemo-embolization in a VX2 Rabbit Model.

PURPOSE: To demonstrate that stability is a crucial parameter for theranostic properties of Lipiodol®-based emulsions during liver trans-arterial chemo-embolization. MATERIALS AND METHODS: We compared the theranostic properties of two emulsions made of Lipiodol® and doxorubicin in two successive animal experiments (One VX2 tumour implanted in the left liver lobe of 30 rabbits). Emulsion-1 reproduced one of the most common way of preparation (ratio of oil/water: 1/1), and emulsion-2 was designed to obtain a water-in-oil emulsion with enhanced stability (ratio of oil/water: 3/1, plus an emulsifier). The first animal experiment compared the tumour selectivity of the two emulsions: seven rabbits received left hepatic arterial infusion (HAI) of emulsion-1 and eight received HAI of emulsion-2. 3D-CBCT acquisitions were acquired after HAI of every 0.1 mL to measure the densities' ratios between the tumours and the left liver lobes. The second animal experiment compared the plasmatic and tumour doxorubicin concentrations after HAI of 1.5 mg of doxorubicin administered either alone (n = 3) or in emulsion-1 (n = 6) or in emulsion-2 (n = 6). RESULTS: Emulsion-2 resulted in densities' ratios between the tumours and the left liver lobes that were significantly higher compared to emulsion-1 (up to 0.4 mL infused). Plasmatic doxorubicin concentrations (at 5 min) were significantly lower after HAI of emulsion-2 (19.0 µg/L) than emulsion-1 (275.3 µg/L, p < 0.01) and doxorubicin alone (412.0 µg/L, p < 0.001), and tumour doxorubicin concentration (day-1) was significantly higher after HAI of emulsion-2 (20,957 ng/g) than in emulsion-1 (8093 ng/g, p < 0.05) and doxorubicin alone (2221 ng/g, p < 0.01). CONCLUSION: Stabilization of doxorubicin in a water-in-oil Lipiodol®-based emulsion results in better theranostic properties.

Elevated plasma ferritin and busulfan pharmacodynamics during high-dose chemotherapy regimens in children with malignant solid tumors.

Hepatic veno-occlusive disease (HVOD) is a frequent complication during hematopoietic stem-cell transplantation (HSCT). A strong relationship has been demonstrated between busulfan exposure and HVOD for busulfan-cyclophosphamide and allogeneic HSCT in adults. Busulfan disposition after the first intake was studied in 77 children treated for solid malignancies with high-dose busulfan-containing regimens and autologous HSCT. Busulfan was combined with cyclophosphamide and melphalan (n=30), melphalan (n=27), and thiotepa (n=20). No relationship was observed between busulfan exposure and HVOD. In contrast, plasma ferritin at baseline was higher in patients with HVOD (750 ng/ml (20-3,110)) compared with those without HVOD (189 ng/ml (8-3,967), P=0.012). Multivariate analysis showed that a ferritin level exceeding 300 ng/ml was the only risk factor for HVOD with an odds ratio of 4.0 (confidence interval 95% (1.5-11.2), P=0.0071). A high ferritin level at baseline was explained by the diagnosis of neuroblastoma, related treatments and transfusions.

Human pharmacokinetic study of heated intraperitoneal oxaliplatin in increasingly hypotonic solutions after complete resection of peritoneal carcinomatosis.

PURPOSE: We studied the pharmacokinetics of heated intraoperative intraperitoneal (i.p.) oxaliplatin (LOHP) solution and its safety profile in increasingly hypotonic solutions. This is the first clinical study of i.p. chemohyperthermia with hypotonic solutions. METHODS: Patients with peritoneal carcinomatosis (PC) underwent complete cytoreductive surgery followed by intraoperative i.p. chemohyperthermia (IPCH) with successive dextrose solutions of 300, 200, 150 and 100 mosm/l. LOHP (460 mg/m(2)) was administered in 2 liters of solution/m(2) at an i.p. temperature of 42-44 degrees C for 30 min. IPCH was performed using an open procedure (skin pulled upwards) with a continuous closed circuit. Patients received intravenous leucovorin (20 mg/m(2)) and 5-fluorouracil (400 mg/m(2)) just before IPCH to maximize the effect of LOHP. i.p. plasma and tissue samples were analyzed by means of atomic absorption spectrophotometry. Sixteen consecutive patients with PC of either gastrointestinal or peritoneal origin were treated. The safety of the procedure was studied. RESULTS: Pharmacokinetics: The mean duration of the entire procedure was 7.7 +/- 2.6 h. Half the LOHP dose was absorbed within 30 min at all dose levels. Absorption was not higher with hypotonic solutions than with isotonic solutions. The area under the curve of LOHP in plasma did not increase with decreasing osmolarity of the i.p. solutions. Intratumoral LOHP penetration was high; it was similar to that at the peritoneal surface, and about 18 times higher than that in nonbathed tissues. LOHP penetration was not significantly increased by using hypotonic solutions. SAFETY: There was a very high incidence of unexplained postoperative peritoneal bleeding (50%) and unusually severe thrombocytopenia in the 150 and 100 mosm/l groups. CONCLUSION: Contrary to experimental studies, this clinical study showed no increase in tumoral or systemic penetration of LOHP with i.p. hypotonic solutions (200, 150 or 100 mosm/l) during IPCH. A high incidence of i.p. hemorrhage and thrombocytopenia was observed.

Protective effect of nisoldipine on dipyridamole-induced myocardial ischemia: correlation with exercise electrocardiography.

BACKGROUND: Nisoldipine, a dihydropyridine calcium channel blocker with strong coronary dilatative action, is commonly used in the treatment of myocardial ischaemia; its beneficial effect on effort angina has been demonstrated by several previous reports. Infusion of dipyridamole in doses sufficient to provoke myocardial ischaemia in patients with significant coronary artery disease is used safely in imaging studies for diagnostic purposes. OBJECTIVE: To evaluate the potential effect of nisoldipine on dipyridamole-induced ischaemia and to compare the results with the effect of nisoldipine on exercise-induced ischaemia. METHOD: Twelve patients (10 men and two women, mean age 62 +/- 8 years) with significant coronary artery disease (at least 70% lumen reduction in at least one major coronary vessel) were selected for inclusion in the study. In accordance with the inclusion criteria, the patients exhibited an ischaemic diagnostic response to a multistage exercise electrocardiography stress test (> 0.15 mV ST segment depression compared with the resting electrocardiographic tracing) and to a dipyridamole-echocardiography test (transient left ventricular dyssynergy of contraction during infusion of dipyridamole up to 0.84 mg/kg over 10 min), after 3 days' cessation of antianginal treatment. After treatment with oral nisoldipine (10 mg twice daily) was introduced, the patients repeated the two tests, within 18 days of the first evaluation. RESULTS: The dipyridamole-echocardiography test was positive for ischaemia in 12 patients who were not receiving nisoldipine and in eight patients who were receiving the drug (100% and 67% respectively, P < 0.05). In the eight patients who gave positive dipyridamole-echocardiography tests both with and without treatment, dipyridamole time (time to onset of dyssynergy during the test) increased from 7.9 +/- 2.9 min to 10.2 +/- 3.1 min (P < 0.01). In these patients, no significant changes were observed, at ischaemia, in the severity and extent of induced dyssynergy, evaluated as wall motion score index (each of 16 left ventricular segments scored from 1 = normal to 4 = dyskinetic) after treatment (score variations from baseline to ischaemia: 0.20 +/- 0.11 without nisoldipine and 0.16 +/- 0.06 with nisoldipine; NS). Variations in dipyridamole time (arbitrarily considered to be 15 min in the negative dipyridamole-echocardiography test) were significantly correlated with variations in exercise time (duration of exercise to exhaustion or diagnostic positive response on the electrocardiogram): r = 0.75 (P < 0.01). No significant differences were recorded in rate-pressure product (beats/min x mmHg x 100) at peak ischaemia between patients who were or were not receiving nisoldipine, during either the exercise electrocardiography stress test (233 +/- 36 with nisoldipine and 244 +/- 39 without nisoldipine; NS) or the dipyridamole-echocardiography test (147 +/- 21 with nisoldipine and 133 +/- 30 without nisoldipine; NS). CONCLUSION: Nisoldipine treatment can protect from dipyridamole-induced ischaemia, being associated with a longer stress time, and completely preventing the development of ischaemia in some patients. The therapy-induced changes in ischaemic threshold during the dipyridamole-echocardiography test correlate with variations in exercise tolerance.

Endogenous digitalis-like factors in human milk.

We measured the concentration of endogenous digitalis-like factors (EDLFs) in milk or colostrum of women during nursing on different days after delivery. EDLF concentrations were assayed by a solid-phase RIA involving antidigoxin antibodies and by a radioreceptor assay (RRA) involving human placenta Na+/K(+)-ATPase. The mean (SD) EDLF concentrations as measured by RIA were 35.6 (19.4) ng of digoxin equivalents per liter in milk samples (n = 37) and 61.3 (12.5) ng/L in colostrum samples (n = 5); the mean EDLF concentration as measured by RRA in milk samples (n = 11) was 573 (717) ng/L (range 0-2098). EDLF concentration in milk is greater than circulating concentrations in healthy adults but is comparable with serum concentration in the third trimester of pregnancy. In milk and serum samples (n = 8) collected at the same time, heating and (or) extracting with Sep-Pak C18 cartridges before the RIA produced significantly different EDLF values from those in untreated serum (P less than 0.001) and milk (P = 0.035). EDLF in milk appeared to be not bound or weakly bound to milk protein, as indicated by the fact that boiling did not increase the digoxin-like immunoreactivity.