title: Methylene diphosphonate-conjugated adriamycin liposomes: preparation, characteristics, and targeted therapy for osteosarcomas in vitro and in vivo.
abstract: Methylenediphosphonate (MDP)-conjugated adriamycin liposomes (MDP-LADMs) were prepared using mild dynamic dialysis equilibrium method, and their targeted therapeutic effects against osteosarcomas and metastatic SOSP-M lung nodules were evaluated in vivo. The drug loading and encapsulation efficiency of the MDP-LADMs were measured via high-performance liquid chromatography, and their size and morphology of the MDP-LADMs were determined using transmission electron microscopy and a particle size analyzer, respectively. Cells apoptosis were evaluated by flow cytometry and caspase-3 activity. The targeted therapeutic effects of MDP-LADMs against UMR106 and SOSP-M osteosarcoma cells were evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Tumor growth and animal survival rates were evaluated after UMR106 osteosarcomas were established in Sprague-Dawley rats and SOSP-M pulmonary metastatic osteosarcoma model were established in nude mice, respectively. The results show that the average diameter of the MDP-LADMs was 152 ± 14 nm, and their ADM encapsulation efficiency was 91.7% with respect to a 250 μg/ml of loading efficiency. The conjugation efficiency between technetium-MDP and LADMs was 87.6%. Infrared spectra results of the samples dissolved in deuterated water confirmed that the methylenediphosphonate (MDP) was conjugated with LADMs through hydrogen bonding. The toxicity assay revealed a median lethal dose of 26.78 mg/kg for MDP-LADMs, which was significantly higher than doses observed for free ADM of 9.64 mg/kg (P < 0.05) and LADMs of 15.02 mg/kg(P < 0.05). Tumor growth and animal survival in the MDP-LADMs group were significantly higher than those in the ADM-only, MDP-only (P < 0.01) and LADMs groups (P < 0.05). These findings indicate that MDP-LADMs have higher therapeutic efficacy against osteosarcomas, demonstrate lower toxicity and their clearly targets osteosarcomas more clearly than the stand-alone systems, making them as a promising novel targeted therapy for the treatment of osteosarcoma.
authors.affiliation: Key Laboratory of Biomedical Information Engineering of Education Ministry, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China. wudaocheng@mail.xjtu.edu.cn
authors.forename: Daocheng
authors.initials: D
authors.lastname: Wu
authors.forename: Mingxi
authors.initials: M
authors.lastname: Wan
mesh_terms: D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D053148:Caspase 3 / Q000378:metabolism; D045744:Cell Line, Tumor; D004164:Diphosphonates / Q000494:pharmacology*; D004195:Disease Models, Animal; D004317:Doxorubicin / Q000031:analogs & derivatives* / Q000494:pharmacology; D016503:Drug Delivery Systems; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D046529:Microscopy, Electron, Transmission; D009362:Neoplasm Metastasis / Q000188:drug therapy; D012516:Osteosarcoma / Q000188:drug therapy* / Q000473:pathology; D011092:Polyethylene Glycols / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000903:Antibiotics, Antineoplastic; D004164:Diphosphonates; C506643:liposomal doxorubicin; D011092:Polyethylene Glycols; C027474:methylene diphosphonate; D004317:Doxorubicin; C505407:CASP3 protein, human; C505409:Casp3 protein, mouse; C505410:Casp3 protein, rat; D053148:Caspase 3