Hyperthermia-triggered UK release nanovectors for deep venous thrombosis therapy.

Deep vein thrombosis (DVT) is a common and lethal complication of surgery. In the clinic, thrombolytic drugs are primarily used for treating DVT. However, the utilization of thrombolytic drugs is limited due to the risk of urokinase (UK)-related hemorrhagic complications. In this paper, a binary eutectic phase-change fatty acid composed of lauric acid and stearic acid was used to block the pores of gold-mesoporous silica core-shell nanoparticles, so as to deliver thrombolytic drugs. The eutectic mixture has a well-defined melting point at 39.2 °C, which can be used as a biocompatible phase-change material for hyperthermia-triggered drug release. The prepared system presents remarkable photothermal effects due to the gold nanoparticles and quick drug release in response to near-infrared irradiation (NIR). In addition, localized hyperthermia could also enhance the lysis of the thrombus. The thrombolytic effect of this system was evaluated in vitro and in vivo. Herein, a rabbit femoral vein thrombosis model was first built for imitating thrombolysis in vivo. The B-ultrasound was then used to monitor the changes in the thrombus after treatment. The results indicated that the reported system could be potentially used to deliver thrombotic drugs in the clinic.