The in vivo temperature monitoring of a microenvironment is significant in biology and nanomedicine research. Luminescent nanothermometry provides a noninvasive method of detecting the temperature in vivo with high sensitivity and high response speed. However, absorption and scattering in complex tissues limit the signal penetration depth and cause errors due to variation at different locations in vivo. In order to minimize these errors and monitor temperature in vivo, in the present work, we provided a strategy to fabricate a samewavelength dual emission ratiometric upconversion luminescence nanothermometer based on a hybrid structure composed of upconversion emissive PbS quantum dots and Tm-doped upconversion nanoparticles. The ratiometric signal composed of two upconversion emissions working at the same wavelength, but different luminescent lifetimes, were decoded via a time-resolved technique. This nanothermometer improved the temperature monitoring ability and a thermal resolution and sensitivity of~0.5 K and~5.6% K −1 were obtained in vivo, respectively.

Combinational administration of chemotherapy (CT) and photothermal therapy (PTT) has been widely used to treat cancer. However, the scheduling of CT and PTT and how it will affect the therapeutic efficacy has not been thoroughly investigated. The challenge is to realize the sequence control of these two therapeutic modes. Herein, we design a temperature sensitive upconversion nanocomposite for CT-PTT combination therapy. By monitoring the microscopic temperature of the nanocomposite with upconversion luminescence, photothermal effect can be adjusted to achieve thermally triggered combination therapy with a sequence of CT, followed by PTT. We find that CT administered before PTT results in better therapeutic effect than other administration sequences when the dosages of chemodrug and heat are kept at the same level. This work proposes a programmed method to arrange the process of combination cancer therapy, which takes full advantage of each therapeutic mode and contributes to the development of new cancer therapy strategies.

Persistent luminescence (PL) bioimaging provides an optimal method of eliminating autofluorescence for a higher resolution and sensitivity because of the absence of excitation light. However, ultraviolet light is still necessary in common energy charging processes, which limits its reactivation in vivo because of its low penetration depth. In the present study, we introduce a type of hybrid nanocluster (UCPL-NC) composed of upconversion nanoparticles, β-NaYbF:Tm@NaYF, and persistent nanoparticles, ZnGaGeO:0.5%Cr, which can be activated by a 980 nm laser and exhibits an afterglow at 700 nm to realize near-infrared (NIR) to NIR UCPL bioimaging. The PL of the UCPL-NCs can be reactivated even when covered with a 10 mm pork. We demonstrate that these polyethylene glycol-modified phospholipid-functionalized UCPL-NCs can be reactivated in vivo and applied in the PL lymphatic imaging on small animals.

Inhomogeneous heating by photothermal therapy (PTT) during cancer treatment often results in the recurrence of tumors. Thus, integrating PTT with chemotherapy (CHT) may provide a complementary treatment for enhanced therapeutic efficiency. Herein, this study develops a hollow structured polymer-silica nanohybrid (HPSN) as a nanocarrier to simultaneously deliver the anticancer drug paclitaxel and photothermal agent palladium phthalocyanine to tumors through enhanced permeation and the retention effect. A combinational CHT/PTT therapy on mice bearing aggressive tumor grafts is conducted. The highly malignant tumor model, which recurs after sole treatment of PTT, can be eradicated by the combined CHT/PTT treatment. In addition, most of the off-targeted HPSN nanocarriers can be excreted through a hepatobiliary pathway in about 10 d. Serology results show that the fast-clearable HPSN can significantly reduce the side effect of the loaded paclitaxel drug. The present work provides an alternative approach for combinational cancer treatment with high therapeutic efficiency.