Publication Date:
2018-03-14
Description:
Purpose Trastuzumab combined with Doxorubicin (DOX) demonstrates significant clinical activity in human epidermal growth factor receptor-2 (HER2)-positive breast cancer (BC). However, emergence of treatment resistance and trastuzumab associated cardiotoxicity remain clinical challenges. In an effort to improve patient outcome, we have developed and evaluated novel tri-functional immunoliposomes (TFIL) that target HER2-receptors on BC cells and CD3-receptors on T-lymphocytes, and deliver DOX. Methods Trastuzumab (anti-HER2) and OKT-3 (anti-CD3) antibodies were conjugated to liposomes using a micelle-transfer method. Cytotoxicity of targeted immunoliposomes loaded with DOX was examined in vitro on HER2-positive BC cells (BT474), with peripheral blood monocytic cells (PBMC) as immune effector cells. Results TFIL demonstrated high antibody-liposome conjugation ratios (100–130 μg protein/μmol phospholipid) and cargo capacity (0.21 mol:mol drug:lipid), highly efficient DOX loading (〉90%), a particle size favorable for extended circulation (~150 nm), and good stability (up to 3 months at 4°C). In the presence of PBMCs, TFIL showed complete killing of BT474 cells, and were superior to mono-targeted trastuzumab-bearing liposomes, non-targeted liposomes, and free Trastuzumab and DOX. Conclusions Novel anti-HER2xCD3 + DOX TFIL show promise as a means to both engage immune cells against HER2 positive breast cancer cells and deliver chemotherapy, and have the potential to improve clinical outcomes.
Print ISSN:
0724-8741
Electronic ISSN:
1573-904X
Topics:
Chemistry and Pharmacology
