Theranostics 2019; 9(3):747-760. doi:10.7150/thno.29989
Lectin-Mediated pH-Sensitive Doxorubicin Prodrug for Pre-Targeted Chemotherapy of Colorectal Cancer with Enhanced Efficacy and Reduced Side Effects
1. Medical Isotopes Research Center and Department of Radiation Medicine, School of Basic Medical Sciences, Peking University, Beijing 100191, P. R. China
2. Key Laboratory of Protein and Peptide Pharmaceuticals, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P. R. China
3. Medical and Healthy Analytical Center, Peking University Health Science Center, Beijing 100191, P. R. China
4. Department of Ultrasonography, Peking University Third Hospital, Beijing 100191, P. R. China
Doxorubicin (DOX) has been clinically used as a broad-spectrum chemotherapeutic agent for decades, but its clinical application is hindered by the lack of tumour specificity, severe cardiotoxicity and haematotoxicity. Pre-targeted strategies are highly tumour-specific, therapeutic approaches. Herein, a novel pre-targeted system was constructed, aiming to enhance anticancer efficacy of DOX and maximally reduce its side effects.
Methods: The DOX prodrug (bDOX) was first synthesized by conjugating DOX with mini-PEGylated (mPEGylated) biotin through a pH-sensitive bond. During the pre-targeted treatment, avidin was first administrated. After an optimized interval, bDOX was second administrated. The nontoxic prodrug bDOX was eventually transformed into the toxic anticancer form (DOX) by a pH-triggered cleavage specifically in tumour cells. The drug efficacy and side effect of the two-step, pre-targeted treatment were fully compared with free DOX in vitro and in vivo.
Results: The prodrug bDOX was quite stable under neutral conditions and nearly nontoxic, but was immediately transformed into the toxic anticancer form (DOX) under acidic conditions. Compared to free DOX, the pre-targeted bDOX exhibited a higher cellular uptake by human colorectal tumour cells (LS180 and HT-29 cells). In vivo evaluation performed on LS180 xenograft animal model demonstrated that the pre-targeted bDOX achieved a much more significant tumour inhibition than free DOX. The largely decreased, unwanted bystander toxicity was demonstrated by changes in body weight, cardiomyocyte apoptosis, blood routine examination and splenic pathological changes.
Conclusion: The high therapeutic efficacy, together with the minimal side effects, of this easily synthesized, pre-targeted system exhibited immense potentiality for the clinical application of DOX delivery.
Keywords: pre-targeted strategy, avidin, biotin, doxorubicin prodrug, chemotherapy
Yao M, Ma X, Zhang X, Shi L, Liu T, Liang X, Zhao H, Li X, Li L, Gao H, Jia B, Wang F. Lectin-Mediated pH-Sensitive Doxorubicin Prodrug for Pre-Targeted Chemotherapy of Colorectal Cancer with Enhanced Efficacy and Reduced Side Effects. Theranostics 2019; 9(3):747-760. doi:10.7150/thno.29989. Available from http://www.thno.org/v09p0747.htm