ROS-activatable nanocomposites for CT imaging tracking and antioxidative protection of mesenchymal stem cells in idiopathic pulmonary fibrosis therapy.

Mesenchymal stem cell (MSC) transplantation is emerging as a promising approach in the treatment of idiopathic pulmonary fibrosis (IPF), while it is still impeded by several challenges, including unsatisfactory treatment outcomes due to the poor survival of transplanted MSCs, and the lack of non-invasive and long-term imaging modality for tracking the behavior of MSCs. Herein, copper-based nanozyme (CuxO NPs) and gold nanoparticles (Au NPs) were encapsulated in oxidation-sensitive dextran (Oxi-Dex), a dextran derivative with reactive oxygen species (ROS)-responsiveness, forming a kind of novel nanocomposites (assigned as RSNPs) to act as ROS scavengers and computer tomography (CT) imaging tracers. After being internalized by MSCs, RSNPs enabled continuous CT imaging tracking of the transplanted MSCs for 21 days in IPF treatment, obtaining the location and distribution of the transplanted MSCs. Once MSCs were attacked by oxidative stress, the intracellular RSNPs could activate ROS clearance on demand by releasing CuxO NPs, thereby enhancing the therapeutic efficacy against IPF by improving cell survival. Taken together, a novel multifunctional RSNP was fabricated to label MSCs for CT imaging tracking and clearing superfluous ROS, presenting a promising high-efficient IPF therapy.

Au-Pt nanozyme-based multifunctional hydrogel dressing for diabetic wound healing.

Diabetic chronic wound healing is a critical clinical challenge due to the particularity of wound microenvironment, including hyperglycemia, excessive oxidative stress, hypoxia, and bacterial infection. Herein, we developed a multifunctional self-healing hydrogel dressing (defined as OHCN) to regulate the complex microenvironment of wound for accelerative diabetic wound repair. The OHCN hydrogel dressing was constructed by integrating Au-Pt alloy nanoparticles into a hydrogel (OHC) that formed through Schiff-base reaction between oxidized hyaluronic acid (OHA) and carboxymethyl chitosan (CMCS). The dynamic cross-linking of OHA and antibacterial CMCS imparted the OHCN hydrogel dressing with excellent antibacterial and self-healing properties. Meanwhile, Au-Pt alloy nanoparticles endowed the OHCN hydrogel dressing with the functions of lowering blood glucose, alleviating oxidative damage, and providing O2 by simulating glucose oxidase and catalase. Through a synergistic combination of OHC hydrogel and Au-Pt alloy nanoparticles, the resulted OHCN hydrogel dressing significantly ameliorated the pathological microenvironment and accelerated the healing rate of diabetic wound. The proposed nanozyme-decorated multifunctional hydrogel offers an efficient strategy for the improved management of diabetic chronic wound.

Ferromagnetic Vortex Iron Oxide Nanorings Modified with Integrin ß1 Antibody for Targeted MRI Tracking of Human Mesenchymal Stem Cells.

Mesenchymal stem cells (MSCs) have demonstrated great potential for tissue engineering and regenerative medicine applications. Noninvasive and real-term tracking of transplanted MSCs in vivo is crucial for studying the distribution and migration of MSCs, and their role in tissue injury repair. This study reports on the use of ferrimagnetic vortex iron oxide (FVIO) nanorings modified with anti-human integrin ß1 for specific recognition and magnetic resonance imaging (MRI) tracking of human MSCs (hMSCs). Integrin ß1 is highly expressed at all stem cell proliferation and differentiation stages. Therefore, the anti-integrin ß1 antibody (Ab) introduced in FVIO targets integrin ß1, thus enabling FVIO to target stem cells at any stage. This is unlike the traditional MRI-based monitoring of transplanted stem cells, which usually requires pre-labeling the stem cells with tracers before injection. Because of the ability to recognize hMSCs, the Ab-modified FVIO nanotracers (FVIO-Ab) have the advantage of not requiring pre-labeling before stem cell transplantation. Furthermore, the FVIO-Ab nanotracers have high T*2 contrast resulting from the unique magnetic properties of FVIO which can improve the MRI tracking efficiency of stem cells. This work may provide a new way for stem cell labeling and in vivo MRI tracking, thus reducing the risks associated with stem cell transplantation and promoting clinical translation.

Recent Development of Conductive Hydrogels for Tissue Engineering: Review and Perspective.

In recent years, tissue engineering techniques have been rapidly developed and offer a new therapeutic approach to organ or tissue damage repair. However, most of tissue engineering scaffolds are nonconductive and cannot establish effective electrical coupling with tissue for the electroactive tissues. Electroconductive hydrogels (ECHs) have received increasing attention in tissue engineering owing to their electroconductivity, biocompatibility, and high water content. In vitro, ECHs can not only promote the communication of electrical signals between cells, but also mediate the adhesion, proliferation, migration, and differentiation of different kinds of cells. In vivo, ECHs can transmit the electric signal to electroactive tissues and activate bioelectrical signaling pathways to promote tissue repair. As a result, implanting ECHs into damaged tissues can effectively reconstruct physiological functions related to electrical conduction. In this review, an overview about the classifications and the fabrication methods of ECHs is first presented. And then, the applications of ECHs in tissue engineering, including cardiac, nerve, skin, and skeletal muscle tissue, are highlighted. At last, some rational guidelines for designing ECHs toward clinical applications are provided.

Case Report: Fainting During Acupuncture Treatment.

CONTEXT: The first issue to be considered in acupuncture is the safety of and adverse effects from treatment. Fainting is an uncommon adverse reaction. Some researchers believe that fainting is related to the mechanism underlying acupuncture treatment, but due to moral and technical issues, studies involving fainting during the acupuncture process haven't been conducted. OBJECTIVE: The study intended to determine if specific risk factors are associated with fainting during acupuncture treatment. DESIGN: The research team performed 2 case studies involving fainting during acupuncture. SETTING: The study took place in the Physiotherapy Departments of the Leribe Motebang Hospital and the Mamohau Hospital in the Kingdom of Lesotho. PARTICIPANTS: Participants were 2 out of 2050 patients who received acupuncture treatment between October 2017 and April 2018 at one of the hospitals. They had fainted, with different clinical manifestations, during acupuncture treatment. Their main symptoms were dizziness, general weakness associated forehead sweating, palpitations, dyspnea, and nausea. RESULTS: In both cases, the patient had complained of hunger before treatment. Both claimed that they had never experienced such a situation previously. CONCLUSIONS: The research team suggests that the fainting occurred for the patients in the two case studies secondary to the hungry state. Hunger may be one of the most important causes of fainting connected to acupuncture. The failure of a practitioner to perform treatment for fainting in a timely and effective manner, or his or her improper handling of it, can lead to serious consequences. Therefore, factors that may cause fainting should be minimized to avoid their occurrence during acupuncture.