Search

Optofluidic regulation of blood microflow in vivo represents a significant method for investigating illnesses linked to abnormal changes in blood circulation. Currently, non-invasive strategies are limited to regulation within capillaries of approximately 10 μm in diameter because the adaption to blood pressure levels in the order of several hundred pascals poses a significant challenge in larger microvessels. In this study, using laser-induced microbubble formation within microvessels of the mouse auricle, we regulate blood microflow in small vessels with diameters in the tens of micrometers. By controlling the laser power, we can control the growth and stability of microbubbles in vivo. This controlled approach enables the achievement of prolonged ischemia and subsequent reperfusion of blood flow, and it can also regulate the microbubbles to function as micro-pumps for reverse blood pumping. Furthermore, by controlling the microbubble, narrow microflow channels can be formed between the microbubbles and microvessels for assessing the apparent viscosity of leukocytes, which is 76.9 ± 11.8 Pa·s in the in vivo blood environment. The proposed design of in vivo microbubble valves opens new avenues for constructing real-time blood regulation and exploring cellular mechanics within living organisms. [ABSTRACT FROM AUTHOR]

Circulating inflammatory cells in eyes have emerged as early indicators of numerous major diseases, yet the monitoring of these cells remains an underdeveloped field. In vivo flow cytometry (IVFC), a noninvasive technique, offers the promise of real‐time, dynamic quantification of circulating cells. However, IVFC has not seen extensive applications in the detection of circulating cells in eyes, possibly due to the eye's unique physiological structure and fundus imaging limitations. This study reviews the current research progress in retinal flow cytometry and other fundus examination techniques, such as adaptive optics, ultra‐widefield retinal imaging, multispectral imaging, and optical coherence tomography, to propose novel ideas for circulating cell monitoring. [ABSTRACT FROM AUTHOR]

A major cause of death in cancer patients is distant metastasis of tumors, in which circulating tumor cells (CTCs) are an important marker. Photoacoustic flow cytometry (PAFC) can monitor CTCs in real time, non‐invasively, and label‐free; we built a PAFC system and validated the feasibility of PAFC for monitoring CTCs using in vivo animal experiments. By cultivating heavily‐pigmented and moderately‐pigmented melanoma cells, more CTCs were detected in mice inoculated with moderately‐pigmented tumor cells, resulting in more distant metastases and poorer survival status. Tumor cells with lower melanin content may produce more CTCs, increasing the risk of metastasis. CTC melanin content may be down‐regulated during the metastatic which may be a potential indicator for assessing the risk of melanoma metastasis. In conclusion, PAFC can be used to assess the risk of melanoma metastasis by dynamically monitoring the number of CTCs and the CTC melanin content in future clinical diagnoses. [ABSTRACT FROM AUTHOR]

The controlled rotation of individual cells plays a crucial role in enabling three-dimensional multi-angle observation of cellular structure, function, and dynamic processes. Reported cell rotation techniques often struggle to strike a balance between high precision and simple control, and they exhibit limited control flexibility, typically achieving only uniaxial cell rotation. In this study, we propose a cell rotation technique in three dimensions based on optofluidics, which utilizes optical tweezers to immobilize the cell and exploits the asymmetry of the surrounding flow to drive cell rotation. By adjusting the focal position of the optical tweezers, cells can be positioned within various flow profiles, enabling control of the rotation speed, rotation direction, and rotation axis of cells. This approach simplifies the manipulation procedure, achieving desirable control precision and greater rotation flexibility. Using our approach, multi-angle surface imaging projections of target cells can be rapidly obtained, followed by capturing the cell contour data from the images. By combining the cell contour data with corresponding angular position information, we have reconstructed the 3D surface of the target cell. We have employed this technique in experiments for the analysis of red blood cell morphology. Based on the constructed 3D surface images of diverse-shaped red blood cells, we quantified structural parameters including cell surface area, volume, sphericity, and surface roughness, which demonstrates the potential application of this cell rotation technique for cellular morphological analysis. [ABSTRACT FROM AUTHOR]

Optical coherence tomography angiography (OCTA) in dermatology usually suffers from low image quality due to the highly scattering property of the skin, the complexity of cutaneous vasculature, and limited acquisition time. Deep‐learning methods have achieved great success in many applications. However, the deep learning approach to improve dermatological OCTA images has not been investigated due to the requirement of high‐performance OCTA systems and difficulty of obtaining high‐quality images as ground truth. This study aims to generate proper datasets and develop a robust deep learning method to enhance the skin OCTA images. A swept‐source skin OCTA system was employed to create low‐quality and high‐quality OCTA images with different scanning protocols. We propose a model named vascular visualization enhancement generative adversarial network and adopt an optimized data augmentation strategy and perceptual content loss function to achieve better image enhancement effect with small amount of training data. We demonstrate the superiority of the proposed method in skin OCTA image enhancement by quantitative and qualitative comparisons. [ABSTRACT FROM AUTHOR]

Chemodynamic therapy (CDT) has received widespread attention due to its selectivity and oxygen independence, and is an emerging therapeutic methodology aimed at converting hydrogen peroxide (H2O2) into hydroxyl radicals (˙OH). Despite the overexpression of H2O2 in solid tumors, the content is too low for efficient CDT. Here, the integration of H2O2 self-supply and photothermal response was achieved using the synthesized nanoparticles, which are CuS/CaO2@PCM (phase change material) nanoparticles. After NIR irradiation, the thermo-responsive PCM was melted to precisely release CuS and CaO2 from nanoparticles. In response to the acidic tumor microenvironment (TME), CaO2 can produce a large amount of H2O2 to participate in a Fenton-like reaction. In turn, the generated ˙OH induces a series of oxidative damage that triggers apoptosis. Meanwhile, CuS converts photon energy into heat via photothermal therapy (PTT) to enhance the antitumor effect. The in vitro and in vivo therapeutic outcomes demonstrated that CuS/CaO2@PCM nanoparticles efficiently generate toxic H2O2 and hyperthermia at the tumor site, thus enabling enhanced CDT and PTT effects. This therapeutic strategy offers a self-amplified synergistic treatment paradigm for tumors. [ABSTRACT FROM AUTHOR]

Breast cancer is the most common cancer, and triple‐negative breast cancer (TNBC) has the highest metastasis and mortality rate among all breast cancer subtypes. Rujifang is a traditional Chinese medicine formula with many years of clinical application in breast cancer treatment. Here, we aim to investigate the effects of Rujifang on circulating tumor cell (CTC) dynamics and the tumor microenvironment in a ZsGreen/luciferase double‐labeled TNBC orthotopic model. We report that the number of CTCs monitored by in vivo flow cytometry (IVFC) strongly correlates with disease progression. Rujifang treatment decreased the number of CTCs and suppressed the distant metastasis of TNBC. Moreover, immunofluorescence analysis revealed that Rujifang treatment could affect the tumor microenvironment by downregulating Kindlin‐1, which has been reported to promote metastasis of TNBC. Our study provides evidence of the anti‐metastatic effect of Rujifang against TNBC in an animal model using fluorescent cell lines. The results suggest the potential therapeutic value of Rujifang as an anti‐metastatic drug, however, further clinical trials are needed to validate these findings in humans. [ABSTRACT FROM AUTHOR]

Soluble CD83 (sCD83) exerts immunosuppressive functions in many autoimmune diseases, including experimental autoimmune uveitis (EAU), but the cells and mechanisms involved are unclear. This study showed that CD83+ B cells were the main sources of sCD83. They alleviated the symptoms of EAU and decreased the percentage of T cells and DCs in the eyes and lymph nodes. These CD83+ B cells decreased IL‐1β, IL‐18 and IFN‐γ secretion by DCs through sCD83. sCD83 interacted with GTPase Ras‐related protein (Rab1a) in DCs to promote Rab1a accumulation in autolysosomes and inhibit mTORC1 phosphorylation and NLRP3 expression. Hence, CD83+ B cells play a regulatory role in EAU by secreting sCD83. The lack of regulation of CD83+ B cells might be an important factor leading to hyperimmune activation in patients with autoimmune uveitis. CD83+ B cells suppress activated DCs in uveitis, indicating the potential therapeutic role of CD83+ B cells in uveitis. [ABSTRACT FROM AUTHOR]

Flow cytometry (FC) is a versatile tool with excellent capabilities to detect and measure multiple characteristics of a population of cells or particles. Notable advancements in in vivo photoacoustic FC, coherent Raman FC, microfluidic FC, and so on, have been achieved in the last two decades, which endows FC with new functions and expands its applications in basic research and clinical practice. Advanced FC broadens the tools available to researchers to conduct research involving cancer detection, microbiology (COVID‐19, HIV, bacteria, etc.), and nucleic acid analysis. This review presents an overall picture of advanced flow cytometers and provides not only a clear understanding of their mechanisms but also new insights into their practical applications. We identify the latest trends in this area and aim to raise awareness of advanced techniques of FC. We hope this review expands the applications of FC and accelerates its clinical translation. [ABSTRACT FROM AUTHOR]

Optical tweezers are ideal tools for cell manipulation in vivo due to their non-contact trapping ability. In the current studies, the optical trapping of cells can only be achieved in light-permeable organs. It is important to expand the application of optical tweezers to opaque tissues and organs, where biological activities are the primary focus of biomedical research. However, the optical manipulation of cells in these opaque organs cannot be imaged using a conventional transillumination microscope due to the opacity of these organs. Here, we use optical tweezers to trap erythrocytes and measure the cell deformability in mouse liver, which are imaged with oblique back-illumination microscopy (OBM). In the microscope system, two fibers are fixed at the same oblique angle on both sides of the microscopic objective, illuminating the trapping target asymmetrically. The dual-wavelength OBM strategy allows for obtaining a differential phase contrast image in a single-shot by color channel separation. The OBM can image the flowing and trapped erythrocytes in vivo in real-time. Furthermore, the erythrocyte deformability in vivo is evaluated with optical tweezers. The spring stiffness in vivo is 8.2 ± 2.1 μN m−1, which is obtained by stretching the trapped cells with blood drag flow. Our works make it possible to utilize optical tweezers to study the live cell dynamics in opaque organs, which will expand the application of optical tweezers in the fields of biomechanical studies. [ABSTRACT FROM AUTHOR]

Background: Laboratory investigations have demonstrated that near-infrared (NIR) light treatment can reduce amyloid-β burden in models of Alzheimer's disease (AD). However, previous clinical studies are rather insufficient.Objective: Before starting a large-scale clinical trial, we performed a pilot study to characterize the efficacy of NIR light for AD patients.Methods: Twenty participants with mild to moderate AD were assigned randomly to the intervention (1060-1080 nm and 800-820 nm NIR light treatment for 12 weeks) or control group (without sham treatment). Safety and efficacy were evaluated at baseline, week 4, 8, and 12, and 4 weeks after treatment.Results: In the intervention and control groups at week 12, mean changes from baseline on the Alzheimer's Disease Assessment Scale-Cognitive (ADAS-Cog) were -3.1 and -1.3 (p = 0.5689). Mean changes from baseline on the Activities of Daily Living (ADL) were -3.6 versus 3.1 (p = 0.0437). Mean changes from baseline on the Mini-Mental State Examination (MMSE) were 4.4 versus 1.0 (p = 0.0253). The percentage of participants who exhibited a change larger than 4 points from baseline to week 12 was determined for the intervention and control groups on the ADAS-Cog (57% versus 29%), ADL (29% versus 0%), and MMSE (57% versus 14%). Treatment with NIR light did not increase the incidence of adverse events in participants.Conclusion: NIR light treatment appears to be safe and potentially beneficial for AD patients. It improved cognitive function and activities of daily living. The preliminary data encouraged us to launch a large-sample, multicenter, double-blind clinical trial. [ABSTRACT FROM AUTHOR]

Platelets buoy up cancer metastasis via arresting cancer cells, enhancing their adhesion, and facilitating their extravasation through the vasculature. When deprived of intracellular and granular contents, platelet decoys could prevent metastatic tumor formation. Inspired by these, we developed nanoplatesomes by fusing platelet membranes with lipid membranes (P-Lipo) to restrain metastatic tumor formation more efficiently. It was shown nanoplateletsomes bound with circulating tumor cells (CTC) efficiently, interfered with CTC arrest by vessel endothelial cells, CTC extravasation through endothelial layers, and epithelial-mesenchymal transition of tumor cells as nanodecoys. More importantly, in the mouse breast tumor metastasis model, nanoplateletsomes could decrease CTC survival in the blood and counteract metastatic tumor growth efficiently by inhibiting the inflammation and suppressing CTC escape. Therefore, nanoplatelesomes might usher in a new avenue to suppress lung metastasis. Nanoplateletsomes were inaugurated to restrain metastatic tumor formation efficiently through decoy and active targeting, serving as a platform to orchestrate the inhibition of circulating tumor cell survival and metastasis. [Display omitted] [ABSTRACT FROM AUTHOR]