In vivo Imaging Biodistribution Profile of a New Macrocyclic Gadolinium Chelate as a Highly Stable Multifunctional MRI Contrast Agent

Gadolinium contrast agents (CAs) are integral components of clinical magnetic resonance imaging (MRI). However, safety concerns have arisen regarding the use of gadolinium CAs, due to their association with nephrogenic systemic fibrosis (NSF). Furthermore, recently the long-term retention of Gd²⁺-based CAs in brains patients with normal renal function raised another possible safety issue. The safety concerns of Gd²⁺-based CAs have been based on the ligand structure of Gd²⁺-based CAs, and findings that Gd²⁺-based CAs with linear ligand structures showed much higher incidences of NSF and brain retention of CAs than Gd²⁺-based CAs with macrocyclic ligand structure. In the current study, we report the in vivo biodistribution profile of a new highly stable multifunctional Gd²⁺-based CA, with macrocyclic ligand structure (HNP-2006). MR imaging using HNP-2006 demonstrated a significant contrast enhancement in many different organs. Furthermore, the contrast enhanced tumor imaging using HNP-2006 confirmed that this new macrocyclic CA can be used for detecting tumor in the central nervous system. Therefore, this new multifunctional HNP-2006 with macrocyclic ligand structure shows great promise for whole-body clinical application.

Metronomic oral paclitaxel shows anti-tumor effects in an orthotopic mouse model of ovarian cancer / 부인종양

OBJECTIVE: The purpose of this study was to compare the in vivo anti-tumor efficacy of a mucoadhesive, lipid-based, oral paclitaxel formulation (DHP107) with traditional, intraperitoneal (IP) paclitaxel using an orthotopic mouse model of chemotherapy-sensitive SKOV3ip1 ovarian cancer. METHODS: To determine the optimal therapeutic dose of oral paclitaxel, DHP107 was administered per os to female athymic nude mice at 0, 25, or 50 mg/kg twice per week. Control mice received 100 microL saline once per week. IP injections of paclitaxel at 5 mg/kg once per week were used for comparison. To evaluate the potential therapeutic effect of metronomic DHP107 chemotherapy, mice received DHP107 50 mg/kg once per week per os, which was compared with 25 mg/kg twice per week and with vehicle-treated controls. RESULTS: Low-dose DHP107 (25 mg/kg) twice per week was as effective as IP paclitaxel (5 mg/kg once a week) but high-dose DHP107 (50 mg/kg once per week) was less effective at inhibiting tumor growth in an orthotopic mouse model (88%, 82%, and 36% decrease in tumor weight, respectively). Mice that received 25 mg/kg DHP107 twice per week or 50 mg/kg DHP107 once per week per os had a significant decrease in tumor weight compared with vehicle-treated controls (p<0.01, both doses). CONCLUSION: Metronomic oral chemotherapy with DHP107 showed anti-tumor efficacy in vivo similar to IP paclitaxel in an orthotopic mouse model.