Benzylguanidine and Galactose Double-Conjugated Chitosan Nanoparticles with Reduction Responsiveness for Targeted Delivery of Doxorubicin to CXCR 4 Positive Tumors

Benzylguanidine, a small cationic and amphiphilic molecule, exhibits a high affinity to C-X-C chemokine receptor type 4 (CXCR 4) and a membrane penetration ability. It has not been used as a functional moiety of nanocarriers for the systemic delivery of chemotherapeutic drugs in tumor therapy. In this study, we investigated the membrane penetration of benzylguanidine-conjugated nanocarriers and their efficiency and safety for targeted delivery of doxorubicin (DOX) in CXCR 4 positive tumors. We conjugated the benzylguanidine bearing guanidinobenzoic acid onto the cystamine bismethacrylamide cross-linked chitosan-poly(methyl methacrylate) nanoparticles, which were then decorated with lactobionic acid (abbreviated as LGCC NPs). A small proportion of LGCC NPs were able to directly penetrate the plasma membrane to enter cells, thereby circumventing endocytic vesicles. The DOX-loaded LGCC NPs (LGCC NPs/DOX) displayed good stability under extracellular physiological conditions and reduction-triggered drug release under high glutathione (GSH) concentration. Moreover, LGCC NPs/DOX showed an increase in tumor-targeted cellular uptake through receptor-mediated endocytosis, enhanced endo/lysosomal escape, and a high nuclear distribution. More importantly, LGCC NPs/DOX significantly suppressed the in vitro and in vivo proliferation of CXCR 4 positive hepatocarcinoma and breast cancer. The findings provide a guideline for the combined application of benzylguanidine and other functional groups in antitumor nanomedicines.