The nanofiber materials of three-dimensional spatial structure synthesized by electrospun have the characteristics of high porosity, high specific surface area, and high similarity to the natural extracellular matrix (ECM) of the human body. These are beneficial for absorbing wound exudate, effectively blocking the invasion of external bacteria, and promoting cell respiration and proliferation, which provides an ideal microenvironment for wound healing. Moreover, electrospun nanofiber dressings can flexibly load drugs according to the condition of the wound, further promoting wound healing. Recently, electrospun nanofiber materials have shown promising application prospects as medical dressings in clinical. Based on current research, this article reviewed the development history of wound dressings and the principles of electrospun technology. Subsequently, based on the types of base material, polymer-based electrospun nanofiber dressing and electrospun nanofiber dressing containing drug-releasing factors were discussed. Furthermore, the application of electrospun nanofiber dressing on skin tissue is highlighted. This review aims to provide a detailed overview of the current research on electrospun nanomaterials for wound healing, addressing challenges and suggesting future research directions to advance the field of electrospun dressings in wound healing.
3 May 2021 in Proceedings of the National Academy of Sciences
To realize RNA interference (RNAi) therapeutics, it is necessary to deliver therapeutic RNAs (such as small interfering RNA or siRNA) into cell cytoplasm. A major challenge of RNAi therapeutics is the endosomal entrapment of the delivered siRNA. In this study, we developed a family of delivery vehicles called Janus base nanopieces (NPs). They are rod-shaped nanoparticles formed by bundles of Janus base nanotubes (JBNTs) with RNA cargoes incorporated inside via charge interactions. JBNTs are formed by noncovalent interactions of small molecules consisting of a base component mimicking DNA bases and an amino acid side chain. NPs presented many advantages over conventional delivery materials. NPs efficiently entered cells via macropinocytosis similar to lipid nanoparticles while presenting much better endosomal escape ability than lipid nanoparticles; NPs escaped from endosomes via a “proton sponge” effect similar to cationic polymers while presenting significant lower cytotoxicity compared to polymers and lipids due to their noncovalent structures and DNA-mimicking chemistry. In a proof-of-concept experiment, we have shown that NPs are promising candidates for antiviral delivery applications, which may be used for conditions such as COVID-19 in the future.
After myocardial infarction, the myocardial microenvironment is altered by cardiomyocyte loss, inflammation, and extracellular matrix degradation, creating a hostile environment that severely limits bone marrow‐derived mesenchymal stem cell (BMSC) survival, migration, and differentiation. The BMSCs may differentiate into cardiomyocyte‐like cells in vitro. However, this potential remains significantly limited in vivo because of the lack of supportive signals and conducive microenvironments. To overcome these challenges, this study presents a novel injectable biomimetic microtissue system containing a dual biomimetic extracellular matrix scaffold consisting of Janus Basic Nanotubes, laminin, stromal‐derived factor‐1 alpha, and vascular endothelial growth factor (JLSV) for BMSC delivery (JLSV–BMSC microtissue) designed to mimic the natural myocardial microenvironment. In vitro experiments showed that the microtissue enhanced BMSC survival, proliferation, migration, anti‐apoptotic capacity, and paracrine signaling under oxygen–glucose deprivation conditions. In vivo studies have shown that the microtissue significantly improves BMSC retention at the infarct site, directs their differentiation into cardiomyocytes and endothelial cells, reduces myocardial fibrosis and apoptosis, and promotes angiogenesis, contributing to improved cardiac remodeling and functional recovery. These results suggest that the JLSV–BMSC microtissue is a promising therapeutic strategy for myocardial infarction that addresses the critical challenges of stem cell‐based therapies.
18 November 2024 in Journal of Translational Medicine
Mesenchymal stem cells (MSCs) have been proposed to treat osteoarthritis (OA) for many years. However, clinical outcomes have been inconsistent due to biological variation between patients, differences in tissue source and preparation of the MSCs, and type of donor (e.g. allogenic versus autologous). Here, we test the hypothesis that inconsistent clinical outcomes are related to variations in the stemness and senescence of the injected autologous adipose-derived (AD) MSCs. In the prospective randomized trial, 45 knee OA patients were divided into two groups: Group 1 (n = 22) patients treated with high tibial osteotomy (HTO) alone and Group 2 (n = 23) patients treated with HTO followed by intra-articular injection of autologous AD-MSCs (HTO + AD-MSCs). MRI and X-ray were performed pre-operation and 12 months post-operation. WOMAC and VAS score were collected four times, every 6 months over a 24-month follow-up. We observed the proliferation and stemness of AD-MSCs selected from the 5 patients showing the most improvement and from the 5 patients with the least improvement, and completed further in vitro experiments including beta-galactosidase activity, reactive oxygen species and bioinformatic analysis. The results showed that patients treated with HTO + AD-MSCs had a significant reduction in knee OA severity as compared to patients treated with HTO alone. Moreover, we discovered that proliferation and colony forming efficiency of AD-MSCs selected from the 5 patients showing the most improvement performed significantly better than cells selected from the 5 patients with the least improvement. AD-MSCs from the patients with the most improvement also had lower amounts of senescent cells and intracellular reactive oxygen species. Clinical outcomes of autologous AD-MSCs therapy in knee osteoarthritis are correlated with stem cell stemness and senescence. Our study highlights emerging opportunities and trends in precision medicine that could potentially improve autologous MSC-based therapies.
Flow‐mediated vasodilation (FMD) is used for assessment of vascular endothelial function in humans as a predictor of cardiovascular events. It has been challenging to carry it on preclinical murine models due to the diminutive size of the femoral artery. Here, we present a new approach to accurately measure the blood velocity and femoral artery diameters of mice by acquiring Doppler optical coherence tomography and optical coherence tomography angiography continuously within 1 single experimental scanning protocol. Using the 3‐dimensional imaging and new velocity algorithm, the measurement precision of diameter, blood flow, velocity and wall shear stress are improved to 0.91%, 11.0%, 10.7% and 14.0%, respectively. FMD of healthy mouse femoral artery measured by this method was 11.96% ± 0.98%, which was blunted to 5.69% ± 0.4% by intravenous administration of endothelial nitric oxide synthase inhibitor (L‐NG‐Nitroarginine methyl ester), in agreement with that reported in the literature.
Oblique scanning laser ophthalmoscopy (oSLO) is a recently developed technique to provide three-dimensional volumetric fluorescence imaging in retinas over a large field of view, without the need for depth sectioning. In this study, we present volumetric fluorescein angiography (vFA) at 200 B-scans per second in mouse retina in vivo by oSLO. By using a low-cost industrial CMOS camera, imaging speed was improved to 2 volumes per second, ∼10 times more than our previous results. Enabled by the volumetric imaging, we visualized hemodynamics at single capillary level in a depth-dependent manner, and provided methods to quantify capillary hematocrit, absolute capillary blood flow speed, and detection of capillary flow stagnancy and stalling at different vascular layers. The quantitative metrics for capillary hemodynamics enhanced by volumetric imaging can offer valuable insight into vision science and retinal pathologies.