In vivo controlled release and prolonged antitumor effects of 2-methoxyestradiol solid lipid nanoparticles incorporated into a thermosensitive hydrogel

A two-phase delivery system involving local injections of solid lipid nanoparticles (SLNs) -loaded hydrogel was developed using 2-methoxyestradiol as a model anticancer drug. This approach improves the effectiveness of conventional treatments for subcutaneous tumors and avoids that solid lipid nanoparticles are rapidly cleared from the circulation following systemic administration. The specific aim of the study presented in this article was to investigate the in vivo release, delivery and antitumor effects of 2-ME SLNs entrapped in a hydrogel. The results indicated that the hydrogel could deliver fluorescence-marked SLNs to tumor masses and cancer cells, exhibiting a controlled release of 2-ME SLNs over 46 days following a zero-order model. After treatment with the 2-ME SLN-loaded hydrogel, BALB/c mice that had been inoculated with syngeneic 4T1 breast cancer cells displayed significantly more tumor growth suppression for at least 21 days than those treated with a hydrogel containing the free drug, which ...