No abstract

An injectable hydrogel sustained drug release system could be a promising technique for in situ treatment. Herein, an injectable hydrogel was prepared for photothermal-chemo therapy of cancer based on the thermosensitive liposomal hydrogel (Lip-Gel). The Lip-Gel system was fabricated by encapsulation of the NIR-II photothermal agent (DPP–BTz) and chemotherapy drugs (GEM) in thermosensitive liposomes and then combined with hydrogel precursor solution. The hydrogel precursor was used as an injectable flowing solution at room temperature and transferred into a cross-linked gel structure at physiological temperature. After being injected into the tumor, DPP–BTz in the Lip-Gel system can generate heat under irradiation of 1064 nm laser, breaking the thermosensitive liposomes and releasing GEM to kill tumor cells. From the treatment results, the Lip-Gel system showed a significant antitumor effect through chemo-/photothermal therapy combination therapy triggered by the NIR-II laser. This work provides a useful scheme for the development of drug delivery and drug treatment directions for local cancer therapy.

Traditional hydrogels have drawbacks such as surgical implantation, large wound surfaces, and uncontrollable drug release during tumor treatment. In this paper, targeted nanomedicine has been combined with injectable hydrogel for photothermal–chemotherapy combination therapy. First, targeted nanomedicine (ICG—MTX) was fabricated by combining near-infrared (NIR) photothermal reagents (ICG) and chemotherapy drugs (MTX). The ICG—MTX was then mixed with the hydrogel precursor and radical initiator to obtain an injectable hydrogel precursor solution. Under the irradiation of NIR light, the precursor solution could release alkyl radicals, which promote the transition of the precursor solution from a liquid to a colloidal state. As a result, the nanomedicine could effectively remain at the site of the tumor and continue to be released from the hydrogel. Due to the targeted nature of MTX, the released ICG—MTX could target tumor cells and improve the accuracy of photothermal–chemo combination therapy. The results indicated that the injectable nanomedicine–hydrogel system has a favorable therapeutic effect on tumors.