In this study, a novel class of multifunctional responsive nanoparticles is designed and fabricated as drug nanocarriers for synergetic chemo–photothermal therapy of tumors. The proposed nanoparticles are composed of a thermo-/pH-responsive poly­(N-isopropylacrylamide-co-acrylic acid) (PNA) nanogel core, a polydopamine (PDA) layer for photothermal conversion, and an outer folic acid (FA) layer as a targeting agent for the folate receptors on tumor cells. The fabricated nanoparticles show good biocompatibility and outstanding photothermal conversion efficiency. The proposed nanoparticles loaded with doxorubicin (DOX) drug molecules are stable under physiological conditions with low leakage of drugs, while rapidly release drugs in environments with low pH conditions and at high temperature. The experimental results show that the drug release process is mainly governed by Fickian diffusion. In vitro cell experimental results demonstrate that the PNA–DOX@PDA–FA nanoparticles can be phagocytized by 4T1 tumor cells and release drugs in tumor cell acidic environments, and confirm that the combined chemo and photothermal therapeutic efficacy of PNA–DOX@PDA–FA nanoparticles is higher than the photothermal therapeutic efficacy or the chemotherapeutic efficacy alone. The proposed multifunctional responsive nanoparticles in this study provide a novel class of drug nanocarriers as a promising tool for synergetic chemo–photothermal therapy of tumors.

A smart-hydrogel-based ultrasensitive grating system with ultra-low detection limit for highly-selective and rapid detection of trace heavy metal ions is developed.

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Highly sensitive elemental analysis of lead carbonate colloids was demonstrated by two-pulse laser-induced plasma spectroscopy. The first laser pulse created a vapor plume with the particulates concentrated in space because of their slower propagation. They were then ablated by an ArF laser pulse that efficiently atomized and excited the lead analyte. The lead emissions were much enhanced, while the background continuum interference was minimized. The detection limit for lead was shown to be 14.2 ppb, compared with 13 ppm achieved by conventional laser-induced breakdown spectroscopy of lead ions in water and 210 ppb for lead aerosols.

Self-regulating insulin controlled-release systems have gained more attention due to their advantages of timely response to blood glucose change and avoiding side effects caused by the high-frequency injection. In this paper, the temperature-responsive monomer N-isopropylacrylamide (NIPAM) and glucose-responsive monomer 3-acrylamidophenylboronic acid (AAPBA) are copolymerized and then grafted with alginate to prepare temperature/glucose dual-responsive copolymers alginate-g-P(NIPAM-co-AAPBA) (Alg-g-PNA). The temperature and glucose responsiveness under different conditions, rheological characteristics, glucose-mediated insulin release, and biotoxicity of the Alg-g-PNA copolymers are studied. The results show that the copolymer solution is in the sol state at 10 °C and insulin can be dispersed uniformly, while it turns into the gel state when the temperature rises to physiological 37 °C for in situ delivery of insulin. Due to the sensitivity to blood glucose levels, the hydrogels can quickly respond to the increase in blood glucose and undergo the gel-to-sol transition and release insulin to reduce blood glucose when the environmental blood glucose rises. Moreover, the hydrogels have good sol−gel transition reversibility in response to changes between normoglycemic and hyperglycemic levels. The cell cytotoxicity results show that the hydrogels have good biocompatibility to be a safe carrier for insulin delivery. The proposed injectable temperature/glucose dual-responsive hydrogels in this study provide a novel type of self-regulating insulin delivery systems for diabetes therapy.