Near infrared light-induced dynamic modulation of enzymatic activity through polyphenol-functionalized liquid metal nanodroplets

Dynamic manipulation of enzymatic activity is a challenging task for applications in chemical and pharmaceutical industries due to the difficult modification and variable conformation of various enzymes.Here, we report a new strategy for reversible dynamic modulation of enzymatic activity by near-infrared light-induced photothermal conversion based on polyphenol-functionalized liquid metal nanodroplets(LM). The metal-phenolic nanocoating not only provides colloidal stability of LM nanodroplets but also generates nanointerfaces for the assembly of various enzymes on the LM nanodroplets. Upon near infrared(NIR) irradiation, the localized microenvironmental heating through photothermal effect of the LM nanodroplets allows tailoring the enzymatic activity without affecting the bulk temperature. A library of functional enzymes, including proteinase K, glucoamylase, glucose oxidase, and Bst DNA polymerase, is integrated to perform a reversible control and enhanced activities even after five times of cycles, demonstrating great potential in bacterial fermentation, bacteriostasis, and target gene amplification.

Detection of near infrared light illumination with the aid of none-metal plasmonic nanocrystals

With the support by the National Natural Science Foundation of China,the research team led by Prof.Luo LinBao(罗林保)at the College of Electronic Sciences and Applied Physics,Hefei University of Technology,developed a simple and highly efficient near infrared light photodetector,which was published in Laser&Photonics Reviews(2016,10:595—602).

Photothermal Effect for Fe_3O_4 Nanoparticles Contained in Micelles Induced by Near-Infrared Light

Near infrared （NIR） light induced photothermal effect for Fe304 nanoparticles, contained in Pluronic F127 micelles, has been studied and it exhibits high photothermal converting efficiency. Heat is found to be rapidly generated in micelles containing Fe304 nanoparticles by NIR laser irradiation. Upon irradiation at 808 nm light and with mass concentration of Pe304 nanoparticles in 4 g/L, the micelle temperature increase is higher than 34 ℃ for 10 min irradiation. The maximum temperature of micelles containing Fe304 nanoparticles in 4 g/L reaches 62 ℃.

Light-triggered NO-releasing nanoparticles for treating mice with liver fibrosis

Liver fibrosis, resulting from chronic liver damage and characterized by the accumulation of extracellular matrix (ECM) proteins, is a characteristic of most types of chronic liver diseases. The activation of hepatic stellate cells (HSC) is considered an essential pathological hallmark in liver fibrosis. Although nitric oxide (NO) can effectively induce HSC apoptosis, the systemic administration of NO is ineffective and may cause severe complications such as hypotension. To overcome this limitation, nanoparticles were designed to target HSCs and release NO locally under the exposure of near infrared light (NIR). To achieve this, upconversion nanoparticle (UCNP) cores were enveloped in mesoporous silica shells (UCNP@mSiO2), which were modified with hyaluronic acid (HA-UCNP@mSiO2) and Roussin’s black salt (RBS). HA molecules recognize and bind to CD44 proteins, which are overexpressed on activated HSCs. Under exposure to a 980-nm NIR laser, the UCNP cores convert the 980-nm wavelength into ultraviolet (UV) light, which then energizes the RBS (NO donors), resulting in an efficient release of NO inside of the HSCs. Once released, NO triggers HSC apoptosis and reverses the liver fibrosis. This targeted and controlled release method provides the theoretical and experimental basis for novel therapeutic approaches to treat hepatic fibrosis.

Smart CU1.75S nanocapsules with high and stable photothermal efficiency for NIR photo-triggered drug release

Thermosensitive drug delivery systems （DDSs） face major challenges, such as remote and repeatable control of in vivo temperature, although these can increase the therapeutic efficacy of drugs. To address this issue, we coated near- infrared （NIR） photothermal Cu175S nanocrystals with pH/thermos-sensitive polymer by in situ polymerization. The doxorubicine （DOX） loading content was up to 40 wt.%, with less than 8.2 wt.% of DOX being leaked under normal physiological conditions （pH = 7.4, 37 ~C） for almost 48 h in the absence of NIR light. These nanocapsules demonstrate excellent photothermal stability by continuous long- term NIR irradiation. Based on the stable and high photothermal efficiency （55.8%）, pre-loaded drugs were released as desired using 808-nm light as a trigger. Both in vitro and in vivo antitumor therapy results demonstrated that this smart nanoplatform is an effective agent for synergistic hyperthermia-based chemotherapy of cancer, demonstratin~ remote and noninvasive control.