Research progress in the application of in situ hydrogel system in tumor treatment

The in situ hydrogel drug delivery system is a hot research topic in recent years. Combining both properties of hydrogel and solution, in situ hydrogels can provide many advantages for drug delivery application, including easy application, high local drug concentration, prolonged drug retention time, reduced drug dose in vivo, good biocompatibility and improved patient compliance, thus has potential in tumor treatment. In this paper, the related literature reports in recent years were reviewed to summarize and discuss the research progress and development prospects in the application of in situ hydrogels in tumor treatment

Polyetherimide-grafted fe₃O₄@SiO₂ nanoparticles as theranostic agents for simultaneous VEGF siRNA delivery and magnetic resonance cell imaging

Engineering a safe and high-efficiency delivery system for efficient RNA interference is critical for successful gene therapy. In this study, we designed a novel nanocarrier system of polyethyleneimine (PEI)-modified Fe3O4@SiO2, which allows high efficient loading of VEGF small hairpin (sh)RNA to form Fe3O4@SiO2/PEI/VEGF shRNA nanocomposites for VEGF gene silencing as well as magnetic resonance (MR) imaging. The size, morphology, particle stability, magnetic properties, and gene-binding capacity and protection were determined. Low cytotoxicity and hemolyticity against human red blood cells showed the excellent biocompatibility of the multifunctional nanocomposites, and also no significant coagulation was observed. The nanocomposites maintain their superparamagnetic property at room temperature and no appreciable change in magnetism, even after PEI modification. The qualitative and quantitative analysis of cellular internalization into MCF-7 human breast cancer cells by Prussian blue staining and inductively coupled plasma atomic emission spectroscopy analysis, respectively, demonstrated that the Fe3O4@SiO2/PEI/VEGF shRNA nanocomposites could be easily internalized by MCF-7 cells, and they exhibited significant inhibition of VEGF gene expression. Furthermore, the MR cellular images showed that the superparamagnetic iron oxide core of our Fe3O4@SiO2/PEI/VEGF shRNA nanocomposites could also act as a T2-weighted contrast agent for cancer MR imaging. Our data highlight multifunctional Fe3O4@SiO2/PEI/VEGF shRNA nanocomposites as a potential platform for simultaneous gene delivery and MR cell imaging, which are promising as theranostic agents for cancer treatment and diagnosis in the future.</p

Liquid metal-templated tin-doped tellurium films for flexible asymmetric pseudocapacitors

Liquid metals can be surface activated to generate a controlled galvanic potential by immersing them in aqueous solutions. This creates energized liquid-liquid interfaces that can promote interfacial chemical reactions. Here we utilize this interfacial phenomenon of liquid metals to deposit thin films of tin-doped tellurium onto rigid and flexible substrates. This is accomplished by exposing liquid metals to a precursor solution of Sn2+ and HTeO2+ ions. The ability to paint liquid metals onto substrates enables us to fabricate supercapacitor electrodes of liquid metal films with an intimately connected surface layer of tin-doped tellurium. The tin-doped tellurium exhibits a pseudocapacitive behavior in 1.0 M Na2SO4 electrolyte and records a specific capacitance of 184.06 F·g-1 (5.74 mF·cm-2) at a scan rate of 10 mV·s-1. Flexible supercapacitor electrodes are also fabricated by painting liquid metals onto polypropylene sheets and subsequently depositing tin-doped tellurium thin films. These flexible electrodes show outstanding mechanical stability even when experiencing a complete 180° bend as well as exhibit high power and energy densities of 160 W·cm-3 and 31 mWh·cm-3, respectively. Overall, this study demonstrates the attractive features of liquid metals in creating energy storage devices and exemplifies their use as media for synthesizing electrochemically active materials. </p

Near-infrared light-mediated rare-earth nanocrystals: recent advances in improving photon conversion and alleviating the thermal effect

With the rapid development of nanotechnology, the unique rare earth lanthanide-doped upconversion nanocrystals (UCNs), which can convert tissue-penetrable near-infrared (NIR) photonic irradiation into ultraviolet, visible and NIR emissions, have found significant potential in bioimaging, diagnosis, therapy, as well as photovoltaics and optical data storage. Despite the promising achievements made in the past decade, critical challenges associated with low upconversion efficiencies and overheating effect induced by NIR laser-irradiation remain in the biomedical fields. More well-defined material design and unique structural modification are highly demanded that are capable of solving these technical concerns and promoting such promising NIR light mediated upconversion nanocrystals for their further practice in medical sciences. Recent advances in upconversion nanomaterials have witnessed the tremendous development towards enhancing the photon converted efficiency, which provides great opportunities in expanding the UCNs potential in bioimaging diagnosis and anticancer therapy. Hence, this review is mainly focusing on summarizing the fundamental principles and strategies to improve the upconversion luminescence and the approaches to reduce the local thermal effect on the basis of rational design of UCNs. In addition, the future perspectives in the development of UCNs for biomedical applications are also proposed