Water-actuated reversible shape-memory polydimethylsiloxane for potential biomedical applications.

Shape memory polymers (SMPs) show great potential in biomedical fields. However, most of the SMPs are not suitable for use in the human body due to their deleteriousness and harsh actuation conditions. It is important to diversify SMPs that could be actuated in the human body environment. Herein, we construct a reversible shape-memory polydimethylsiloxane (RSMPDMS) based on a feasible strategy by deposing the PDMS-salt layer with dynamic micro-creases on the pure PDMS layer. Testing results reveal that it equips with self-expanding, bio-compatibility, drug storage-release and good mechanical toughness. The RSMPDMS could be variously shaped, such as ring, coil, and spiral. The prepared samples present efficient deformation-recovery with high mechanical stability during water absorption-desorption cycles. Moreover, the RSMPDMS is confirmed biocompatible by cell viability analysis and cell fluorescent labeling method, accompanied with efficient drug storage-release. The novel-designed RSMPDMS may contribute to the development of new shape memory biomedical materials.

Safety and accuracy of transbronchial lung cryobiopsy in diagnosing desquamative interstitial pneumonia.

INTRODUCTION: Transbronchial lung cryobiopsy (TBLC) is a new technique to obtain specimens for diagnosis of interstitial lung disease (ILD) in recent years. The objective of this study is to evaluate the safety and the diagnostic accuracy of TBLC in patients of desquamative interstitial pneumonia (DIP). METHODS: In this study twelve patients confirmed with DIP were selected from January 2019 to December 2020 at the department of pulmonary and critical care medicine in China-Japan Friendship Hospital. All cases underwent TBLC in a hybrid cone beam CT (CBCT) operation room with a single general anesthesia. The definitive diagnosis was made by a multidisciplinary team that involved clinicians, radiologists and pathologists. This study analyzed the biopsy sample surface areas, main complications and the consistency between TBLC pathology and multidisciplinary discussion (MDD) diagnosis for DIP. RESULTS: An average of 3.1 ± 1.1 specimens were obtained per patient. The mean surface area of the specimen was 23.7 ± 6.1 mm2 . None of the cases had pneumothorax or massive hemorrhage. Ten cases (83.3%) had no or mild bleeding and two cases (16.7%) had moderate bleeding. All cases had the typical pathologic characteristics of DIP, which was highly consistent with the diagnosis of MDD. CONCLUSION: TBLC can obtain sufficient samples for the pathological diagnosis of DIP, which has high security and accuracy in experienced specialist centers.

Polyoxometalate-covalent organic framework hybrid materials for pH-responsive photothermal tumor therapy.

Photothermal therapy (PTT) has become one of the most effective methods for tumor treatment. With the development of medicine, studies focusing primarily on therapeutic and diagnostic agents with desirable biocompatibility, targeting and stability are still of great significance. Heteropoly blue (HPB) is an ideal photothermal therapy agent (PTA) with decent photothermal conversion efficiency. Covalent organic frameworks (COFs) are considered to be good carriers with excellent biocompatibility. Due to their superior characteristics, such as being adjustable, and having high thermal stability and porous structures, COFs have been broadly applied in various fields. In this study, HPB was successfully in situ loaded into a COF via a one-pot method. The resultant HPB@COF platform exhibited desirable biocompatibility, pH-responsive release properties and high tumor inhibition efficiency, which can be used for PTT to effectively inhibit tumor growth. Our work provides a valuable paradigm for the fabrication of safer and effective HPB@COF NPs for future pH-responsive photothermal therapy.

Sensitive visual detection of intracellular zinc ions based on signal-on polydopamine carbon dots.

The concentration of intracellular zinc ions is a significant clinical parameter for diagnosis. However, it is still a challenge for direct visual detection of zinc ions in cells at single-cell level. To address this issue, herein, water-soluble amino-rich polydopamine carbon quantum dots (PDA-CQDs) were successfully synthesized, with strong blue-green fluorescence as the probes for zinc ions detection in cells. The structure and properties of PDA-CQDs were confirmed by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transformed infrared (FT-IR), UV-visible spectrophotometry (UV-vis), and fluorescence spectroscopy. Importantly, by successfully linking salicylaldehyde (SA) to PDA-CQDs via nucleophilic reaction, the FL quenching and Zn ions induced FL-recovering system was built up, thus offering a signal-on platform for the detection of zinc ions. This PDA-CQDs-SA nanoprobe can be applied for the detection of Zn2+with a detection limit of 0.09µM, with good biocompatibility confirmed using cytotoxicity assay. Of significance, the results of fluorescence bioimaging showed that PDA-CQDs-SA is able to detect Zn2+in single-cell visually, with the detection limit of Zn ions in cells as low as 0.11µM per cell, which was confirmed using flow cytometry. Therefore, this work offers a potential probe for Zn2+detection in cells at single-cell level, towards the precise diagnosis of zinc ions related diseases.

Polyoxometalate Modified by Zeolite Imidazole Framework for the pH-Responsive Electrodynamic/Chemodynamic Therapy.

Electrodynamic therapy (EDT) and chemodynamic therapy (CDT) have the potential for future tumor treatment; however, their underlying applications are greatly hindered owing to their inherent drawbacks. The combination of EDT and CDT has been considered to be an effective way to maximize the superiorities of these two ROS-based methodologies. However, the development of novel nanomaterials with "one-for-all" functions still remains a big challenge. In this work, the polyoxometalate nanoparticles (NPs) were decorated using the zeolite imidazole framework (POM@ZIF-8) in order to integrate the EDT with CDT. The resulting POM@ZIF-8 NPs can effectively induce the generation of reactive oxygen species (ROS) via a catalytic reaction on the surface of POM NPs induced by an electric field (E). At the same time, POM@ZIF-8 NPs can catalyze the intracellular H2O2 into ROS via a Fenton-like reaction, thereby achieving the combination of EDT and CDT. Besides, since ZIF-8 is acid-responsive, it can protect normal tissues and avoid side effects. Of great note is that the cytotoxicity and the apoptosis rate of the POM@ZIF-8+E group (80%) were found to be significantly higher than that of the E group (55%). As a result, a high tumor inhibition phenomenon can be observed both in vitro and in vivo. The present study thus provides an alternative concept for combinational therapeutic modality with exceptional efficacy.