Profiling paracrine interactions between hypoxic and normoxic skeletal muscle tissue in a microphysiological system fabricated from 3D printed components.

Disrupted blood flow in conditions such as peripheral artery disease and critical limb ischemia leads to variations in oxygen supply within skeletal muscle tissue, creating regions of poorly perfused, hypoxic skeletal muscle surrounded by regions of adequately perfused, normoxic muscle tissue. These oxygen gradients may have significant implications for muscle injury or disease, as mediated by the exchange of paracrine factors between differentially oxygenated tissue. However, creating and maintaining heterogeneous oxygen landscapes within a controlled experimental setup to ensure continuous paracrine signaling is a technological challenge.

Label-free metabolic optical biomarkers track stem cell fate transition in real time.

Tracking stem cell fate transition is crucial for understanding their development and optimizing biomanufacturing. Destructive single-cell methods provide a pseudotemporal landscape of stem cell differentiation but cannot monitor stem cell fate in real time. We established a metabolic optical metric using label-free fluorescence lifetime imaging microscopy (FLIM), feature extraction and machine learning-assisted analysis, for real-time cell fate tracking.

Cleanroom-Free Microfluidic Device for Natural Induction of Hypoxia in 2D and 3D Tumor Models.

Hypoxia is a common and critical feature of solid tumors that contributes to the plasticity and heterogeneity of the cancer cells. Cancer cell populations take on a region-specific adaptation induced by hypoxia, and each cancer cell population will show different levels of sensitivity and resistance to cancer therapeutics. Therefore, a faithful recapitulation of tumor hypoxia that allows for accurate assessments of hypoxia-induced adaptations, heterogeneity, and response to therapy is needed to develop new therapeutic approaches.

Hypoxic 3D Tumor Model for Evaluating of CAR-T Cell Therapy In Vitro.

Solid tumors contain abnormal physical and biochemical barriers that hinder chimeric antigen receptor (CAR) T cell therapies. However, there is a lack of understanding on how the solid tumor microenvironment (e.g.

Ectopic Expression of a Truncated Isoform of Hair Keratin 81 in Breast Cancer Alters Biophysical Characteristics to Promote Metastatic Propensity.

Keratins are an integral part of cell structure and function. Here, it is shown that ectopic expression of a truncated isoform of keratin 81 (tKRT81) in breast cancer is upregulated in metastatic lesions compared to primary tumors and patient-derived circulating tumor cells, and is associated with more aggressive subtypes. tKRT81 physically interacts with keratin 18 (KRT18) and leads to changes in the cytosolic keratin intermediate filament network and desmosomal plaque formation.

Intracellular and microenvironmental regulation of mitochondrial membrane potential in cancer cells.

Cancer cells have an abnormally high mitochondrial membrane potential (ΔΨ ), which is associated with enhanced invasive properties in vitro and increased metastases in vivo. The mechanisms underlying the abnormal ΔΨ in cancer cells remain unclear. Research on different cell types has shown that ΔΨ is regulated by various intracellular mechanisms such as by mitochondrial inner and outer membrane ion transporters, cytoskeletal elements, and biochemical signaling pathways.

Faultline configurations affecting the entrepreneurial team performance of new generation of returning migrant workers in China: An empirical study based on fuzzy-set qualitative comparative analysis.

As the impact of faultlines is still without a consensus, to figure out how faultlines will hurt or promote the entrepreneurial performance can help the new generation of Chinese migrant workers to start their businesses successfully under the Rural Revitalization Strategy. This study addressed a fuzzy-set qualitative comparative analysis (fsQCA) based on 32 returning entrepreneurial teams from a complexity perspective. We firstly introduced three faultline categories for migrant workers and selected five of the faultlines with high factor loads in each category for further analysis.

Manipulation and Mechanical Deformation of Leukemia Cells by High-Frequency Ultrasound Single Beam.

Ultrasound single-beam acoustic tweezer system has attracted increasing attention in the field of biomechanics. Cell biomechanics play a pivotal role in leukemia cell functions. To better understand and compare the cell mechanics of the leukemia cells, herein, we fabricated an acoustic tweezer system in-house connected with a 50-MHz high-frequency cylinder ultrasound transducer.

A Pillar-Free Diffusion Device for Studying Chemotaxis on Supported Lipid Bilayers.

Chemotactic cell migration plays a crucial role in physiological and pathophysiological processes. In tissues, cells can migrate not only through extracellular matrix (ECM), but also along stromal cell surfaces via membrane-bound receptor-ligand interactions to fulfill critical functions. However, there remains a lack of models recapitulating chemotactic migration mediated through membrane-bound interactions.

E-Cadherin Regulates Mitochondrial Membrane Potential in Cancer Cells.

Epithelial cancer cells often have unusually higher mitochondrial membrane potential (ΔΨ) than their normal counterparts, which has been associated with increased invasiveness in vitro and higher metastatic potential in vivo. However, the mechanisms by which ΔΨ in cancer cells is regulated in tumor microenvironment (TME) remain unclear. In this study, we used an in vitro micropatterning platform to recapitulate biophysical confinement cues in the TME and investigated the mechanisms by which these regulate cancer cell ΔΨ.

Engineering a Vascularized Hypoxic Tumor Model for Therapeutic Assessment.

Solid tumors in advanced cancer often feature a structurally and functionally abnormal vasculature through tumor angiogenesis, which contributes to cancer progression, metastasis, and therapeutic resistances. Hypoxia is considered a major driver of angiogenesis in tumor microenvironments. However, there remains a lack of in vitro models that recapitulate both the vasculature and hypoxia in the same model with physiological resemblance to the tumor microenvironment, while allowing for high-content spatiotemporal analyses for mechanistic studies and therapeutic evaluations.

The complete mitochondrial genome of (Pallas, 1814) from Zhoushan archipelago.

In this study, we used whole genome sequencing to obtain the complete mitochondrial genome of . This mitochondrial genome, consisting of 17,449 base pairs (bp), contains 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs and 2 noncoding control regions (control region and origin of light-strand replication) as those found in other vertebrates. Control region, of 1799 bp in length, is located between tRNA and tRNA.

Membrane-bound SCF and VCAM-1 synergistically regulate the morphology of hematopoietic stem cells.

Membrane-bound factors expressed by niche stromal cells constitute a unique class of localized cues and regulate the long-term functions of adult stem cells, yet little is known about the underlying mechanisms. Here, we used a supported lipid bilayer (SLB) to recapitulate the membrane-bound interactions between hematopoietic stem cells (HSCs) and niche stromal cells. HSCs cluster membrane-bound stem cell factor (mSCF) at the HSC-SLB interface.

Medulloblastoma uses GABA transaminase to survive in the cerebrospinal fluid microenvironment and promote leptomeningeal dissemination.

Medulloblastoma (MB) is a malignant pediatric brain tumor arising in the cerebellum. Although abnormal GABAergic receptor activation has been described in MB, studies have not yet elucidated the contribution of receptor-independent GABA metabolism to MB pathogenesis. We find primary MB tumors globally display decreased expression of GABA transaminase (ABAT), the protein responsible for GABA metabolism, compared with normal cerebellum.

The complete mitochondrial genome of sp.1 (Teleostei, Platycephalidae) obtained by whole genome sequencing.

In this study, we used next-generation sequencing to obtain the complete mitochondrial genome of sp.1. This mitochondrial genome, consisting of 16,552 base pairs (bp), contains 13 protein-coding genes, two ribosomal RNAs, 22 transfer RNAs, and two non-coding control regions (control region and origin of light-strand replication) as those found in other vertebrates.

Engineered in vitro tumor models for cell-based immunotherapy.

Tumor immunotherapy is rapidly evolving as one of the major pillars of cancer treatment. Cell-based immunotherapies, which utilize patient's own immune cells to eliminate cancer cells, have shown great promise in treating a range of malignancies, especially those of hematopoietic origins. However, their performance on a broader spectrum of solid tumor types still fall short of expectations in the clinical stage despite promising preclinical assessments.

Bioengineering tools for probing intracellular events in T lymphocytes.

T lymphocytes are the central coordinator and executor of many immune functions. The activation and function of T lymphocytes are mediated through the engagement of cell surface receptors and regulated by a myriad of intracellular signaling network. Bioengineering tools, including imaging modalities and fluorescent probes, have been developed and employed to elucidate the cellular events throughout the functional lifespan of T cells.

CCR2-targeted micelles for anti-cancer peptide delivery and immune stimulation.

Signaling between the CC chemokine receptor 2 (CCR2) with its ligand, monocyte chemoattractant protein-1 (MCP-1) promotes cancer progression by directly stimulating tumor cell proliferation and downregulating the expression of apoptotic proteins. Additionally, the MCP-1/CCR2 signaling axis drives the migration of circulating monocytes into the tumor microenvironment, where they mature into tumor-associated macrophages (TAMs) that promote disease progression through induction of angiogenesis, tissue remodeling, and suppression of the cytotoxic T lymphocyte (CTL) response. In order to simultaneously disrupt MCP-1/CCR2 signaling and target CCR2-expressing cancer cells for drug delivery, KLAK-MCP-1 micelles consisting of a CCR2-targeting peptide sequence (MCP-1 peptide) and the apoptotic KLAKLAK peptide were synthesized.

Non-invasive Optical Biomarkers Distinguish and Track the Metabolic Status of Single Hematopoietic Stem Cells.

Metabolism is a key regulator of hematopoietic stem cell (HSC) functions. There is a lack of real-time, non-invasive approaches to evaluate metabolism in single HSCs. Using fluorescence lifetime imaging microscopy, we developed a set of metabolic optical biomarkers (MOBs) from the auto-fluorescent properties of metabolic coenzymes NAD(P)H and FAD.

Spatial Regulation of Mitochondrial Heterogeneity by Stromal Confinement in Micropatterned Tumor Models.

Heterogeneity of mitochondrial activities in cancer cells exists across different disease stages and even in the same patient, with increased mitochondrial activities associated with invasive cancer phenotypes and circulating tumor cells. Here, we use a micropatterned tumor-stromal assay (μTSA) comprised of MCF-7 breast cancer cells and bone marrow stromal cells (BMSCs) as a model to investigate the role of stromal constraints in altering the mitochondrial activities of cancer cells within the tumor microenvironment (TME). Using microdissection and RNA sequencing, we revealed a differentially regulated pattern of gene expression related to mitochondrial activities and metastatic potential at the tumor-stromal interface.

Evaluating CAR-T Cell Therapy in a Hypoxic 3D Tumor Model.

Despite its revolutionary success in hematological malignancies, chimeric antigen receptor T (CAR-T) cell therapy faces disappointing clinical results in solid tumors. The poor efficacy has been partially attributed to the lack of understanding in how CAR-T cells function in a solid tumor microenvironment. Hypoxia plays a critical role in cancer progression and immune editing, which potentially results in solid tumors escaping immunosurveillance and CAR-T cell-mediated cytotoxicity.

A Microdevice Platform Recapitulating Hypoxic Tumor Microenvironments.

Hypoxia plays a central role in cancer progression and resistance to therapy. We have engineered a microdevice platform to recapitulate the intratumor oxygen gradients that drive the heterogeneous hypoxic landscapes in solid tumors. Our design features a "tumor section"-like culture by incorporating a cell layer between two diffusion barriers, where an oxygen gradient is established by cellular metabolism and physical constraints.

A cost-effective micromilling platform for rapid prototyping of microdevices.

Micromilling has great potential in producing microdevices for lab-on-a-chip and organ-on-a-chip applications, but has remained under-utilized due to the high machinery costs and limited accessibility. In this paper, we assessed the machining capabilities of a low-cost 3-D mill in polycarbonate material, which were showcased by the production of microfluidic devices. The study demonstrates that this particular mill is well suited for the fabrication of multi-scale microdevices with feature sizes from micrometers to centimeters.