Co‐encapsulation of anti‐BCR‐ABL siRNA and imatinib mesylate in transferrin receptor‐targeted sterically stabilized liposomes for chronic myeloid leukemia treatment

• Published in: Biotechnology and bioengineering 2010-12, Vol.107 (5), p.884-893
• Main Authors: Mendonça, Liliana S, Moreira, João N, de Lima, Maria C. Pedroso, Simões, Sérgio
• Format: Article
• Language: English
• Subjects: anti-BCR-ABL siRNA; Antineoplastic agents; Antineoplastic Agents - metabolism; Benzamides; Bioassays; Biological and medical sciences; Biotechnology; Cell Line, Tumor; Cells; Chemotherapy; CML; Drug Carriers - metabolism; Drug Carriers - pharmacokinetics; Drug resistance; Fundamental and applied biological sciences. Psychology; Gene expression; Health. Pharmaceutical industry; Humans; imatinib; Imatinib Mesylate; Industrial applications and implications. Economical aspects; Inhibitory Concentration 50; Leukemia; liposomes; Liposomes - metabolism; Liposomes - pharmacokinetics; Medical sciences; Miscellaneous; Molecules; Oncogene Proteins v-abl - analysis; Oncogene Proteins v-abl - genetics; Pharmacology. Drug treatments; Piperazines - metabolism; Piperazines - pharmacokinetics; Proteins; Proto-Oncogene Proteins c-bcr - analysis; Proto-Oncogene Proteins c-bcr - genetics; Pyrimidines - metabolism; Pyrimidines - pharmacokinetics; Ribonucleic acid; RNA; RNA, Small Interfering - metabolism; RNA, Small Interfering - pharmacokinetics; Toxicity; transferrin; Transferrin - metabolism; triple-targeting
• ISSN: 0006-3592; 1097-0290; 1097-0290
• DOI: 10.1002/bit.22858

Chronic myeloid leukemia (CML) is triggered by the BCR‐ABL oncogene. Imatinib is the first‐line treatment of CML; however imatinib resistance and intolerance have been detected in many patients. Therefore, new therapeutic approaches are required. The present work aimed at the development and application of transferrin receptor (TrfR) targeted liposomes co‐encapsulating anti‐BCR‐ABL siRNA and imatinib at different molar ratios. The encapsulation yields and drug loading of each molecule was evaluated. Anti‐leukemia activity of the developed formulations co‐encapsulating siRNA and imatinib and of the combination of Trf‐liposomes carrying siRNA and free imatinib under two different treatment schedules of pre‐sensitization was assessed. The results obtained demonstrate that the presence of imatinib significantly decreases the encapsulation yields of siRNA, whereas imatinib encapsulation yields are increased by the presence of siRNA. Cytotoxicity assays demonstrate that the formulations co‐encapsulating siRNA and imatinib promote a 3.84‐fold reduction on the imatinib IC₅₀ (from 3.49 to 0.91 µM), whereas a 8.71‐fold reduction was observed for the pre‐sensitization protocols (from 42.7 to 4.9 nM). It was also observed that the formulations with higher siRNA to imatinib molar ratios promote higher cell toxicity. Thus, the present work describes a novel triple targeting strategy with one single system: cellular targeting (through the targeting ligand, transferrin) and molecular targeting at the BCR‐ABL mRNA and Bcr‐Abl protein level. Biotechnol. Bioeng. 2010;107: 884-893.