The constant and noninvasive tracking of the distribution and degradation of engineered hydrogel scaffolds using fluorescent probes is considered to be one of the important research studies. Conventional fluorophores were simply mixed into hydrogels by physical doping, and they suffered from photoinstability or UV–vis light excitation, which usually led to the potential leak of the fluorescent tag and imprecise tracking results. In this article, upconversion nanoparticles, NaGdF4:Yb3+,Er3+@NaGdF4 (UCNPs) with near-infrared light (NIR) excitation, were synthesized and were coated with polydopamine (PDA). A biodegradable composite hydrogel OSA-I-CMCS-I-UCNPs@PDA (“I” means “linked-by”) was constructed by the UCNPs@PDA, serving as both the construction unit and NIR-excited fluorescent probe, where carboxymethyl chitosan (CMCS) was used as the cross-linker to chemically cross-link UCNPs@PDA and oxidized sodium alginate (OSA) based on dynamic covalent Schiff-base linkages. It is demonstrated that the composite hydrogels possess enhanced mechanical strength, excellent self-healing capacity, injectable performance, and good biocompatibility with the tissue. In addition, the composite hydrogels possess a deep penetrating ability from UCNPs@PDA in vitro through about 10 mm thick chicken strips. A mimetic lysozyme biodegradation test was performed for 108 h in vitro for evaluating the feasibility and accuracy of UCNPs@PDA in tracking the hydrogel degradation. The degradation signals were obtained by the decrease in fluorescence intensity, which were well consistent with the weight changes in composite hydrogels, suggesting the accuracy of the UCNPs@PDA in consecutively monitoring the hydrogel degradation in vitro. With these superior properties, the composite hydrogels are expected to be promising candidates for various biomedical fields, for example, as tissue engineering or delivery carriers in vivo.

An oil-in-water nanoemulsion (O/W NE) is selected as the carrier to encapsulate hydrophobic dual-mode luminescent upconversion nanoparticles (UC NPs) and downconversion (DC) carbon quantum dots (CQDs) inside the oil droplets...

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With the rapid need for new kinds of portable and wearable electronics, we must look to develop flexible, small-volume, and high-performance supercapacitors that can be easily produced and stored in a sustainable way. An integrated system simultaneously converting recyclable energy to electricity and storing energy is sought after. Here we report photovoltaic energy conversion and storage integrated micro-supercapacitors (MSCs) with asymmetric, flexible, and all-solid-state performances constructed from thousands of close-packed upconverting nanoparticles (UCNPs) via an emulsion-based self-assembly process using oleic acid (OA)-capped upconverting nanoparticles. The carbonated-UCNPs supraparticles (CSPs) are further coated with polypyrrole (PPy) to improve their electrochemical performance. Such a design can develop CSPs@PPy as electrode materials with high gravimetric capacitance, 308.6 F g –1 at 0.6 A g –1 . The fabricated MSCs exhibit excellent areal capacitance, C s = 21.8 mF cm –2 at 0.36 A cm –2 and E = 0.00684 mWh cm –2 , and have superior flexibility and cycling ability. The MSC devices have a sensitive near-infrared ray (NIR) photoelectrical response capability, which can capture the NIR of sunlight to convert it into electrical energy and store the electric energy due to an excellent capacitive performance. We propose a method for multifunctional integration of energy conversion and storage, and provide future research directions and potential applications of self-powered flexible wearable photonic electronics.

Paclitaxel (PTX) is a broad-spectrum alkaloid anticancer drug with high therapeutic efficacy. However, PTX has a very low water solubility and its metabolism demonstrates nonlinear pharmacokinetic characteristics, resulting in systemic adverse reactions in clinical applications. Many endeavors are devoted to develop new PTX preparations in response to these obstacles, and some are used in clinical phase of cancer treatment. In particular, highly specific medical intervention at nanoscale is an emerging research field focusing on nanoapproaches to solve clinical problems. In a perspective of nanomedicine, the recent covalent and noncovalent approaches toward PTX formulation on various substrates, as well as their advantages and disadvantages during preclinical researches and clinical applications are herein summarized. It is anticipated that nanotechnology-based drug delivery systems can further enhance therapeutic efficiencies of PTX, by reducing systemic side effects and alleviating severely negative effects on patients.