Jae-Hyeon Lee ^a,1, Seong-Bin Yang ^b,1, Jun-Hyuck Lee ^b, Hansol Lim ^b, Seokwoo Lee ^c, Tae-Bong Kang ^b, Ji-Hong Lim ^a,b, Young Jun Kim ^a, Jooho Park ^a,b

^aDepartment of Biomedical Chemistry, College of Biomedical and Health Science, Konkuk University, Chungju 27478, Republic of Korea
^bDepartment of Applied Life Science, Graduate School, BK21 Program, Konkuk University, Chungju 27478, Republic of Korea
^cCollege of Pharmacy, Chungnam National University, Daejeon 34134, Republic of Korea

¹These authors contributed equally to this work.
Corresponding author : Jooho Park

Heparin is a glycosaminoglycans (GAGs) member and well-known FDA-approved anticoagulant that has been widely used in the clinic for 100 years. It has also been evaluated in various fields for further clinical applications, such as in anti-cancer or anti-inflammatory therapy beyond its anticoagulant effect. Here, we sought to utilize heparin molecules as drug carriers by directly conjugating the anticancer drug doxorubicin to the carboxyl group of unfractionated heparin. Given the molecular action of doxorubicin in intercalating DNA, it is expected to be less effective when structurally combined with other molecules. However, by utilizing doxorubicin molecules to produce reactive oxygen species (ROS), we found that the heparin–doxorubicin conjugates have significant cytotoxic ability to kill CT26 tumor cells with low anticoagulant activity. Several doxorubicin molecules were bound to heparin to provide sufficient cytotoxic capability and self-assembly ability due to their amphiphilic properties. The self-assembled formation of these nanoparticles was demonstrated through DLS, SEM and TEM. The cytotoxic ROS-generating doxorubicin-conjugated heparins could inhibit tumor growth and metastasis in CT26-bearing Balb/c animal models. Our results demonstrate that this cytotoxic doxorubicin-based heparin conjugate can significantly inhibit tumor growth and metastasis, thus showing promise as a potential new anti-cancer therapeutic.