Suppression of Tumor Growth in a Rabbit Hepatic Cancer Model by Boron Neutron Capture Therapy With Liposomal Boron Delivery Systems.

BACKGROUND/AIM: Tumor cell destruction by boron neutron capture therapy (BNCT) is attributed to the nuclear reaction between 10B and thermal neutrons. The accumulation of 10B atoms in tumor cells without affecting adjacent healthy cells is crucial for effective BNCT. We previously reported that several types of liposomal boron delivery systems (BDS) delivered effective numbers of boron atoms to cancer tissues, and showed tumor-growth suppression after thermal neutron irradiation. In the present study, we examined the effects of BNCT after intra-arterial infusion of 10B-borono-dodecaborate (10BSH) by liposomal BDS in rabbit hepatic cancer models. MATERIALS AND METHODS: We prepared 10BSH-entrapped transferrin-conjugated polyethylene glycol liposomes constructed with distearoyl-boron lipid (TF-PEG-DSBL), and performed thermal neutron irradiation at the Kyoto University Institute for Integrated Radiation and Nuclear Science after intra-arterial infusion into rabbit VX-2 hepatic tumors. RESULTS: Concentrations of 10B in VX-2 tumors on delivery with TF-PEG-DSBL liposomes reached 25 ppm on day 3 after the injection. Tumor growth was suppressed by thermal neutron irradiation after intra-arterial injection of this 10BSH-containing liposomal BDS, without damage to normal cells. CONCLUSION: The present results demonstrate the applicability of 10B-containing TF-PEG-DSBL liposomes as a novel intra-arterial boron carrier in BNCT for cancer.

Tumor Growth Suppression With Novel Intra-arterial Chemotherapy Using Epirubicin-entrapped Water-in-oil-in-water Emulsion In Vivo.

BACKGROUND/AIM: A mixture of anticancer agents and iodized poppy seed oil (IPSO) has been widely used for intra-arterial chemotherapy of hepatocellular carcinoma. However, the anticancer agents can easily separate from IPSO, so the therapeutic potential is limited. We developed epirubicin-entrapped water-in-oil-in-water emulsion (WOW-Epi) using a double-membrane emulsification technique. MATERIALS AND METHODS: We delivered WOW-Epi through a hepatic arterial injection to VX2 hepatic tumor rabbit model (1.2 mg/kg). RESULTS: VX2 tumor growth was selectively suppressed in the WOW-Epi-treated group compared with the control treated groups. The accumulation of WOW in nearby cancer cells was confirmed via electron-microscopy. Endocytosis seemed to be the mechanism underlying the uptake of WOW. CONCLUSION: WOW-Epi led to tumour growth suppression in vivo. WOW does not cause toxicity to arterial vessels. WOW-Epi will be hopefully used for repeated intra-arterial chemotherapy to HCC patients in the near future.

Localized amyloidosis at the site of repeated insulin injection in a diabetic patient.

A 60-year-old woman diabetic patient presented with a subcutaneous mass in right lower abdominal quadrant where recombinant human insulin or insulin analogue had been injected for 16 years. Her diabetes has been insulin resistant with insufficient blood glucose control. The mass was extirpated under the suspicion of neoplasm but it was found to consist of diffuse deposition of eosinophilic amorphous materials mixed with inflammatory change. Congo-red staining demonstrated positive red color and yielded green birefringence by polarized microscopy. Pre-digestion with potassium permanganate was incomplete to quench positive Congo-red stains. Immunostains with insulin antibody were positive for this deposition but not so with amylin or AA or AL amyloid. Thus, the mass was considered to be localized amyloidosis composed of iatrogenic A-Ins type amyloid. Thus, the case suggested that her insulin resistance, i.e. refractoriness of insulin treatment, may be ascribed to poor penetration of injected insulin and human insulin itself or its analogue is amyloidogenic to form a local mass.