APL Bioengineering

During tumor growth and progression, cancer cells are exposed to sustained physical confinement and volumetric compression that can alter cell volume, cytoskeletal organization, mechanotransduction, and invasive behavior. However, whether breast cancer cells retain a compression-induced mechanical memory after release from sustained volumetric compression, and how this memory influences subsequent migration and invasion, remains poorly understood. Here, by controlling cell volume using PEG - mediated volumetric compression, we investigated the compression and post-compression recovery responses of MCF-7 breast cancer cells. Cells were compressed for four days, followed by four days of recovery after PEG removal, and analyzed using daily morphological tracking, single-cell time-lapse imaging, F-actin and YAP staining, wound healing assays, and 3D spheroid invasion assays. We show that sustained volumetric compression shifts MCF-7 cells into a compact, jammed-like, low-motility state characterized by reduced morphodynamic remodeling, suppressed collective migration, and limited spheroid invasion. In contrast, post-compression recovery induces a distinct mechanobiological state marked by increased cell area and perimeter, altered single-cell trajectories, heterogeneous F-actin remodeling, enhanced YAP nuclear localization in enlarged recovered cells, accelerated wound closure, and increased spheroid invasion and cell dissemination. These findings suggest that prior volumetric compression can prime breast cancer cells for enhanced migration and invasion after stress release, supporting post-compression recovery as a form of mechanical memory that may contribute to tumor dissemination.

The lung is a common site of metastasis and is continuously deformed by breathing. Whether physiological breathing mechanics influence tumor cell extravasation is unknown. To address this, we developed a mechanically actuated microphysiological system combining perfusable lung-specific microvascular networks with breathing-like cyclic deformation. Under static conditions, lung-specific networks exhibited more lung-like vascular features and higher tumor cell extravasation rates than generic networks. The mechanically actuated device reproduced physiological tissue and vascular deformation, while 24 h of cyclic actuation did not alter vessel viability, permeability, or morphology compared with unactuated controls. Pre-actuation for 24 h, followed by tumor cell perfusion under static conditions, did not alter subsequent extravasation, whereas actuation initiated immediately after perfusion significantly increased extravasation compared with unactuated controls. This biomimetic platform enables direct investigation of how breathing-like vascular deformation influences metastasis and provides a versatile tool for studying vascular mechanobiology in the lung and other mechanically active organs.

The tumor microenvironment plays a pivotal role in tumor development, harboring elements such as endothelial cells, immune cells, fibroblasts, and soluble factors such as transforming growth factor-{beta} (TGF-{beta}) family. TGF-{beta} family regulates cell development and promotes tumor invasion, metastasis, angiogenesis, and endothelial-to-mesenchymal transition (EndoMT). Here, we investigate the effects of TGF-{beta} signaling on vascular remodeling using a three-dimensional (3D) vascular network in a microfluidic device. Using both a co-culture (3D-Co) and simplified endothelial monoculture (3D-CM), we demonstrate that TGF-{beta} signaling reduces the quality and functionality of the vasculature by regressing them. In addition, we observed the upregulation of EndoMT-related markers in mRNA and protein expressions, suggesting the induction of EndoMT in 3D vascular networks. The increased vascular permeability stimulated by TGF-{beta}2 also supports the loss of endothelial identity in the 3D-Co. Transcriptomic analysis revealed the coordinated activation of pathways associated with cell migration and EndoMT, along with the suppression of cell cycle progression. A comparative analysis of two-dimensional (2D) and 3D cultures revealed a fundamentally distinct endothelial response to TGF-{beta}2 in the 3D context, including metabolic reprogramming. These findings demonstrate that the 3D microenvironment critically modulates endothelial responses to TGF-{beta} and enables the emergence of vascular phenotypes not captured in 2D systems. This study provides a more physiologically relevant platform to investigate endothelial dysfunction and vascular remodeling.

Anti-angiogenic cancer therapies attempt to withhold necessary nutrients and oxygen from growing tumors by targeting the major promoters of endothelial cell (EC) angiogenesis: vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR-2). Unfortunately, these treatments are often insufficient, even when coupled with chemotherapies, and fail to significantly increase survival rates. The tumor microenvironment (TME) is mechanically distinct compared to normal tissue, including increased matrix deformations or strains caused by cancer-associated fibroblasts (CAFs). In this report, we detail the specific and independent roles of two tyrosine residues, Y1054 and Y1214, on mechanical activation of VEGFR-2. Furthermore, we characterize CAF biochemical and mechanical signaling and demonstrate how ECs exhibit decreased vessel growth when co-cultured with CAFs and treated with a contractility inhibitor. Using non-phosphorylatable VEGFR-2 mutants, we reveal Y1054 and Y1214 are each necessary for EC angiogenesis, particularly in response to strain. Overall, this research highlights the need to study how mechanics in the TME promote vessel growth and thus tumor progression, which is important to consider when developing future anti-angiogenic therapies.

Immune-epithelial interactions govern the initiation and progression of airway diseases, yet their heterogeneity is difficult to capture using existing in vitro models. Although conventional Transwell and lung-on-chip systems reproduce airway compartmentalisation and permit epithelial-immune interactions, they lack the spatial and analytical resolution needed to visualise dynamic immune behaviour during infection. Here, we present the "Single Cell resolved Airway-Immune Recruitment" (scAIR) platform designed to interrogate immune-epithelial interactions during airway infection. The scAIR device features a modular central chamber accommodating a Transwell insert with primary airway epithelial cells (AECs) pre-differentiated under air-liquid interface (ALI), flanked by immune compartments connected through a precision-patterned microchannel array. This architecture enables real-time single-cell imaging of immune cell migration while preserving epithelial physiology. The scAIR device coupled with a machine learning analysis (MLA) pipeline enables automated tracking and quantification of individual immune cell speed, direction, and behavioural heterogeneity. Using this platform, respiratory syncytial virus (RSV) infection is modelled to generate a type 1 inflammatory airway epithelium that drives neutrophil recruitment. TNF-alpha neutralisation with adalimumab reveals distinct migratory behaviours that are obscured by population-averaged measurements. This integrated platform quantifies airway immune responses during infection and therapeutic modulation, enabling mechanistic studies, drug evaluation, and precision modelling of airway inflammation.

In breast cancer, collagen fiber alignment and the second harmonic generation forward-to-backward ratio (F/B), an optical measurement sensitive to fibril-scale organization within collagen fibers, have each been associated with metastatic outcome. Although both are measured at the tumor-stromal interface, in vitro studies have largely examined them separately, because experimental systems have not allowed the two to be varied independently. To address this technical gap, we used a microfluidic biofabrication approach to generate paired aligned and unaligned regions within 3D collagen hydrogels via extensional strain and varied measured F/B across gels by changing the pre-gel pH. The resulting library covered alignment values reported in breast tumors and F/B values associated with poorer metastatic outcome in invasive ductal carcinoma at matched matrix stiffness, pore diameter, and fiber fraction. In MDA-MB-231 cells, alignment biased migration along the fiber axis without changing migration speed, as expected, but the magnitude of the contact guidance response varied with measured F/B. In contrast, MCF-7 cells showed little overall contact guidance, yet migrated ~30% faster in high F/B than low F/B gels in both aligned and unaligned regions. Together, these results show that cells migrated differently in matrices with similar fiber alignment. Thus, including measured F/B may provide additional information to help anticipate how cells migrate in collagen environments that appear similar based on alignment alone.

ObjectiveStructural adaptations of capillary networks, through angiogenesis, arterialization, and regression, are implicated in many diseases, and gaining a better understanding of the cell-cell interactions that underpin these adaptations may lead to novel therapeutic discoveries for disease management. Endothelial cells and pericytes are the two cell types that comprise capillary networks. Experimental model systems have been developed to study the dynamic interactions between endothelial cells and pericytes, providing valuable insights into capillary development, cell-to-cell communication, and responses to growth factors and therapeutic agents. MethodsIn this study, we present a novel and simple co-culture system that uses commercially available primary human endothelial cells and pericytes, does not require microfluidic perfusion, and allows simultaneous observation of cell morphologies and interactions over time in 60 samples, enabling high-throughput analysis of multiple culture conditions with replicates. ResultsImage analysis pipelines were created to quantify microvascular adaptations, including one to measure colocalization between endothelial cells and pericytes, capturing dynamic coupling and uncoupling associated with capillary stability, angiogenesis, and regression. We validated the ability of our co-culture system to reproducibly represent the effects of fibrotic and angiogenic activation signals, including an FDA-approved drug, on endothelial cells, pericytes, and their coupling. ConclusionThis novel, high-throughput microvascular screening assay enables quantification of microvascular dynamics in response to disease-relevant stimuli and therapeutics in a repeatable, real-time manner.

Endothelial dysfunction is a hallmark of numerous vascular pathologies and is strongly influenced by mechanobiological forces within the vascular microenvironment. While the effects of shear stress have been extensively investigated, the mechanisms by which elevated hydrostatic pressure regulates endothelial junctional organisation remain sparsely investigated. Here, we employed a microfluidic platform to investigate the combined effects of low shear stress (1.4 dyne/cm2) and elevated hydrostatic pressure (~3972 Pa) on endothelial junctional dynamics. Elevated hydrostatic pressure induced marked remodelling of VE-cadherin junctions, characterised by formation of serrated, finger-like structures accompanied by increased YAP1 nuclear localisation and reduced YAP1-VE-cadherin cytoplasmic colocalisation compared to shear stress alone conditions. Further, elevated hydrostatic pressure also demonstrated an increase in cytoplasmic accumulation of EPS8, an actin adaptor protein, and increased cytoplasmic EPS8-VE-cadherin colocalisation. These observations were accompanied by functional changes marked by increased endothelial permeability, and enhanced THP-1 monocyte adhesion, thus suggesting activation of mechanosensitive pathways linked to dynamic junctional reorganisation. Inhibition of PI3K at elevated hydrostatic pressure exhibited a thin VE-cadherin patterning and increased cytoplasmic EPS8-VE-cadherin colocalisation, thus demonstrating a prominent role for PI3K signalling in regulating the junction organisation. Interestingly, Piezo-1 activation using Yoda1 produced context-dependent effects. Under shear stress alone, Yoda1 promoted YAP1 nuclear translocation, reduced YAP1-VE-cadherin colocalisation, increased endothelial permeability but strikingly did not impact THP-1 adhesion compared to shear stress alone conditions. In contrast, under elevated hydrostatic pressure conditions, Yoda1 significantly reduced both endothelial permeability and THP-1 adhesion while increasing YAP1-VE-cadherin colocalisation and decreasing YAP1 nuclear accumulation. Collectively, these findings identify a previously underappreciated elevated hydrostatic pressure-Piezo-1-PI3K signalling axis that regulates endothelial barrier integrity and pro-adhesive endothelial activation through coordinated regulation of VE-cadherin, YAP1, and EPS8. These results highlight elevated hydrostatic pressure as a unique mechanobiological stimulus, distinct from that of shear stress alone and provide novel insights into mechanisms underlying microvascular dysfunction.

Metastatic dissemination is initiated by tumor cells interpreting spatially organized biochemical and biophysical cues that remain difficult to reproduce using conventional migration assays. Here, we developed a computationally guided metastasis-on-a-chip (MET-on-a-chip) platform based on the concept of the Minimally Functional Unit (MFU), in which only the biological components required to answer a defined experimental question are incorporated. The platform consists of two independent culture chambers connected through an array of confined microchannels that permits diffusion of soluble factors while constraining tumor cell migration. Rather than relying on empirical optimization, finite-element COMSOL simulations were first used to predict molecular transport, define growth factor loading conditions, identify biologically relevant exposure regions, and guide the rational design of the microfluidic assay. Computational predictions were experimentally validated using 70-kDa FITC-dextran diffusion and VEGF release studies, confirming the formation of stable spatial concentration gradients across the microfluidic platform. The simulations further demonstrated that both growth factor loading and cell positioning relative to the predicted gradients critically influenced assay performance, leading to the optimization of the platform through spatial reconfiguration of the tumor compartment. Using the optimized configuration, we compared the migratory responses of neuroblastoma, Ewing sarcoma, and osteosarcoma cells to vascular (VEGF-A165) and lymphatic (VEGF-C) chemotactic cues. VEGF-C significantly increased migration through the microchannel array in Ewing sarcoma and osteosarcoma cells, whereas VEGF-A165 produced no significant effect. In contrast, neuroblastoma cells exhibited minimal migration under either condition, revealing tumor-specific differences in responsiveness to VEGF signaling. Together, these findings establish a computationally guided workflow for the rational design of metastasis-on-a-chip assays, in which predictive modeling informs experimental design before biological validation. By substantially reducing empirical trial-and-error while enabling quantitative control over growth factor exposure, this strategy provides a robust framework for developing minimally functional microphysiological systems capable of dissecting individual steps of the metastatic cascade under experimentally defined conditions. Translational Impact StatementMetastatic dissemination remains one of the greatest clinical challenges in pediatric oncology, yet experimental models capable of quantitatively evaluating early migratory events remain limited. The computationally guided MET-on-a-Chip workflow presented here provides a human-relevant platform in which soluble microenvironmental cues can be systematically investigated under controlled and predictive conditions. Although demonstrated here using VEGF-A165 and VEGF-C, the platform can be readily adapted to study virtually any chemotactic factor, cytokine, extracellular vesicle population, or therapeutic candidate involved in metastatic dissemination. The modular MFU design allows biological complexity to be incorporated progressively as dictated by the scientific question, providing a flexible framework for future applications. In the longer term, this workflow could be combined with patient-derived tumor cells, organoids, or biopsy material to investigate patient-specific metastatic behavior and evaluate anti-metastatic therapeutic strategies in a personalized setting. Beyond identifying pro-migratory signaling pathways, the platform may serve as a preclinical tool to prioritize compounds capable of preventing tumor cell dissemination before evaluation in more complex animal models or clinical studies.

Cancer survival rates increase with earlier diagnosis. However, many cancers are diagnosed only after symptoms develop, in the later stages of cancer progression. We need a diagnostic tool that can detect cancer earlier. Circulating tumour cells (CTCs) are cells that detach from the main tumour and can enter the bloodstream. The capture and analysis of CTCs can provide an early indicator of cancer. However, rarity of CTCs in blood makes their efficient capture challenging. Inertial microfluidics can be utilised for a label-free separation of CTCs from white blood cells (WBCs) by manipulating cells in the microchannel based on cell properties, achieving good separation performance. Inertial microfluidic devices mainly rely on size-based separation. However, residual WBC carryover limits complete separation. Here, we show that cell mechanical heterogeneity plays a large role in the separation process and should be considered in the design of these devices. We simulate the migration dynamics of CTCs and WBCs in a straight microchannel using a 3D lattice-Boltzmann-immersed-boundary-finite-element solver. Our results demonstrate that WBC migration behaviour changes depending on the deformability of a CTC. The size and deformability of the cells have been shown to determine the cell-specific heteroclinic orbits leading to different interaction types, these interactions alter WBC migration resulting in more/less WBC carryover. This work highlights that both cell-specific heteroclinic orbits and single cell migration rates should be considered in the design of inertial microfluidics for separation.

Cells in vivo exist in a complex environment where they receive chemical and physical cues from neighboring cells and the extracellular matrix. Suspended, three dimensional (3D) cell culture enables the study of mechanical signals in a controlled in vitro setting where cells can exert forces on the extracellular matrix, and mechanical stimulation can be externally applied. In addition to mechanical cues, tissues in vivo also exhibit spatial heterogeneity and nonplanar topography. To facilitate the development of suspended 3D cell culture models with both spatial and geometric complexity, we previously introduced Suspended Tissue Engineering with Assemblable Microfluidics (STEAM). STEAM is an accessible, modular platform that utilizes fluidic patterning to create multiregional planar and nonplanar suspended cell-embedded 3D tissues. Herein, we further characterize the STEAM dome platform by developing a theoretical model that explains some experimental considerations necessary for successful two-region patterning in a nonplanar construct. We highlight a brief biological application of the planar and nonplanar STEAM platforms by creating simple but physiologically relevant model systems for the bladder, a sphere-like organ with concentric tissue layers and a central lumen that dynamically expands and contracts during filling and voiding. We demonstrate that the suspended configuration of the planar bladder smooth muscle tissue patch induces inherent tension, which can be increased by further straining the tissues; both result in muscle cell alignment along the axis of stretch as shown by a clear peak at 90 degrees in a radial sum analysis of the two dimensional Fast Fourier Transform of images with fluorescent signal from myosin heavy chain 11 immunostaining. Further, we utilize the nonplanar STEAM platform with a human urothelial cell line (HBLAK) and primary bladder smooth muscle cells (HBdSMC) to create a bladder wall model, resulting in a domed, bilayered tissue. STEAM integrates patterning precision, mechanical functionality, and customizability to actualize an accessible and low cost alternative to generate spatially and geometrically complex suspended tissues.

Neural progenitor-stem cells (NPSCs) reside in mechanically dynamic brain microenvironments and give rise to neurons, astrocytes, and oligodendrocytes. Although recent studies have shown that matrix viscoelasticity can influence neural maturation and neurogenic differentiation, its role in primary NPSCs beyond neurogenesis remains less defined. How matrix viscoelasticity or stress relaxation regulates primary NPSC stemness, neuronal and glial differentiation, and the associated matrix-cell mechanotransduction pathways are not well understood. Here, we use alginate hydrogels with independently tunable stiffness and stress relaxation properties to investigate how matrix stress relaxation regulates the fate of primary subventricular zone (SVZ)-derived NPSCs in 3D. The results suggested that matrices with faster stress relaxation enhances stemness maintenance, radial glial-like marker expression, and differentiation of NPSCs toward neuronal, astrocytic, and oligodendrocytic lineages in the corresponding biochemical environments. In mixed neuronal/astrocytic differentiation conditions, fast-relaxing matrices preferentially promote neuronal differentiation. Mechanistically, NPSC responses to matrix stress relaxation involve integrin-mediated adhesion, actomyosin contractility, actin polymerization, and Piezo1 activity, with distinct contributions across differentiation lineages. Together, these findings reveal how matrix stress relaxation regulates primary NPSC stemness and multilineage differentiation through multiple mechanotransduction pathways in 3D.

Mechanobiological cues in the tissue microenvironment increasingly drive pathological fibroblast activation in inflammatory bowel disease (IBD), yet engineered platforms modeling this transition remain limited. Here, a microfluidic gut-on-a-chip microphysiological system and a mesofluidic rotary shaker are used to demonstrate that sustained fluid shear stress alone is necessary and sufficient to drive an irreversible, profibrotic phenotypic switch in primary normal human intestinal fibroblasts. Across both platforms, normal fibroblasts from small and large intestine reproducibly self-organize into three-dimensional (3D) multicellular aggregates within 72 h, independent of shear delivery format, indicating that the transition is governed by mechanical dose rather than device geometry. The resulting aggregates acquire robust -smooth muscle actin (-SMA) expression with aligned stress fibers, contrasting with the -SMA-negative parental population. Scanning electron microscopy (SEM) resolves densely packed cellular microarchitecture embedded in a microfibrillar extracellular network, while ultrastructural serial block-face 3D EM reveals expansive intercellular spaces, stochastic fibrillar extrusions, and electron-dense cytoplasmic material at cell boundaries. Proteomic profiling confirms enrichment of core matrisome components, including collagen subtypes and matrix metalloproteinases. Together, these results establish fluid shear stress as a platform-independent, sufficient mechanical trigger for fibroblast-to-mechanoadaptive transition, positioning microphysiological shear platforms as tractable tools for modeling and targeting early fibrogenesis in IBD.

Intranasal administration provides a noninvasive route for local and systemic drug delivery, yet its clinical effectiveness remains limited by rapid mucociliary clearance and short drug residence times within the nasal cavity. Existing stimulus-responsive nasal hydrogels seek to address this challenge but rely on physiological triggers such as temperature, pH, or ionic strength to induce gelation, resulting in variable performance due to natural differences in the nasal cavity. Here, we present a polyethylene glycol (PEG)-based hydrogel platform that overcomes these limitations through rapid in situ gel formation that is independent of physiological stimuli. The two liquid precursor solutions remain sprayable during administration and rapidly crosslink upon deposition to form a cohesive hydrogel depot. Although this dual-component design presents challenges for compatibility with conventional nasal spray devices, we demonstrate successful delivery using commercially available dual-barrel spray systems. The hydrogel maintained spray performance and regional nasal deposition comparable to conventional aqueous formulations while significantly reducing mucociliary transport to prolong mucosal residence. Importantly, reduced mucociliary transport was achieved without impairing ciliary function or compromising epithelial barrier integrity, addressing key safety considerations for repeated intranasal administration. In addition, the hydrogel altered epithelial uptake and transport of biologics, suggesting its potential to improve the nasal delivery of macromolecular therapeutics that typically exhibit poor bioavailability. The results of these study establish a versatile and clinically translatable approach for enhancing intranasal drug delivery across a broad range of therapeutic applications.

Lymphatic endothelial cell (LEC) function is strongly tied to transitions between button- and zipper-like junctions that control fluid flow into vessels. Published methods quantifying junction morphology are limited to single cell analysis or use few quantitative metrics to describe junctions across LEC monolayers. Therefore, a novel 3-step image analysis pipeline was developed to identify new metrics that quantify differences in button- and zipper-like junctions in LECs. The pipeline used Cellpose, CellProfiler, and Fiji to analyze VE-cadherin expression across lymphatic vessels within a 3D microfluidic chip and quantify VE-cadherin radial intensity, number of objects, object size, branchpoints, end-points, and junction thickness. Tumor necrosis factor (TNF)- exposure produced but-ton-like junctions, and unexposed cells were zippered. Radial intensity was heightened at the cell membrane in zipper-like junctions while perinuclear intensity increased for but-ton-like junctions. Increased branchpoints, endpoints, objects per cell, and junction thick-ness were associated with junction buttoning, while increased object size was associated with junction zippering. Principle component analysis results reinforced these trends and identified metric combinations that represented each junctional state. Overall, this semi-automated pipeline quantified differences in VE-cadherin junction morphology across LEC monolayers and generated new quantitative metrics to expand the tools available for studying junction morphology in lymphatic vasculature.

Oncofetal fibronectin (oFN) is a known biomarker of cancer progression and is involved in events such as epithelial mesenchymal transition and multidrug resistance. It is also understood that fibronectin (FN) and its splice variants are differentially arranged by cancer associated fibroblasts (CAFs) to support cancer cell proliferation and migration. Contrastingly, little is understood about the mechanobiology of oFN, a post-translationally modified FN isoform defined by O-glycosylation of a specific threonine residue. To investigate the architectural features of the oFN matrix, CAFs were simulated by culturing human mammary fibroblasts (HMFs) on stiff polyacrylamide gels (20 kPa) in media collected from HCC-1937 (primary site breast adenocarcinoma) and MDA-MB-231 (metastatic breast adenocarcinoma) cells. As a control, HMFs were also cultured on softer gels representing healthy adipose tissue (2 kPa) in media not exposed to cancer cells. After immunocytochemical analysis, tumor conditioned HMFs displayed an expected CAF-like phenotype that was most prominent with MDA-MB-231 conditioned media. Matrices produced by tumor-conditioned HMFs contained more oFN with structural features mostly following that of the overall dense, aligned FN matrix. Cancer cells reseeded on their corresponding decellularized tumor-associated matrices had greater F-actin/oFN colocalization than control matrix. The lack of distinct oFN topographical cues may indicate that oFN O-glycosylation is more directly involved in biochemical signaling than mechanosignaling through matrix architecture. Together, this study established a platform for investigating stromal oFN which revealed that tumor-conditioned media sourced from cancer cells with different metastatic potential influences HMF activation, leading to distinct total FN and thus oFN matrix microarchitecture features.

Relapse remains a leading cause of treatment failure in acute myeloid leukaemia (AML), making haematopoietic stem cell transplantation (HSCT) the only curative option for many patients. Yet HSCT efficacy is often limited by impaired engraftment, driven by AML-induced remodelling of the bone marrow stem cell niche. Mesenchymal stromal cells (MSCs) are key mediators of niche formation and could, in principle, restore a supportive microenvironment when introduced alongside HSC therapy; but this strategy remains largely untested. A key obstacle to MSC-based therapy is that MSCs acquire a senescent, pro-inflammatory phenotype during standard in vitro expansion. We addressed this by engineering a polymer-laminin presentation system that suppresses senescence and preserves a proliferative, regenerative MSC phenotype during expansion. Then, to investigate potential cell therapy use, we developed a bioengineered in vitro model as a new approach methodology (NAM) for studying disease-driven niche modification. The system consists of MSC spheroids embedded in a synthetic hydrogel within a transwell platform, allowing controlled co-culture of healthy or AML-derived haematopoietic cells, therapeutic MSCs, and chemotherapeutic agents. Using this platform, we modelled an AML-like niche and showed that MSCs expanded via the polymer-laminin system, when introduced alongside HSCs, significantly improved HSCT engraftment relative to both standard-expanded MSCs and HSCT performed without MSC support. These results establish MSC phenotype maintenance as a critical determinant of therapeutic efficacy, and position this NAM as a platform for pre-clinical screening of niche-targeted therapies in AML.

The human pancreas secretes digestive fluid that flows through an extensive ductal network before emptying into the duodenum. However, little is known about how hydrodynamic forces influence pancreatic function and development. We hypothesized that pancreatic cells respond to physiological levels of fluid shear stress. In this study, we developed a microfluidic system featuring reversible sealing between the device layer and the cell culture substrate, enabling (1) conventional open-well cell culture prior to fluid shear stress application and (2) selective patterning of proteins and cells for migration studies. Channel dimensions were chosen to support 24-hour perfusion using standard syringe pumps. Using this platform, we investigated effects of physiological shear stress levels representing basal and activated pancreatic function (2, 8 and 33 mPa) on human iPSC-derived pancreatic progenitor cells. Pancreatic progenitor cells exhibit graded sensitivity to shear stress at the transcriptomic level. Specifically, shear stress upregulated expression of cell cycle-related gene sets; endocrine-associated genes including NEUROG3; and Notch receptor ligands (DLL1, DLL3) in a magnitude-dependent manner. The exposure to unidirectional fluid flow also resulted in a reduction in YAP1 protein content, decreased WWTR1 gene expression, and downregulation of YAP/TAZ target genes. Furthermore, barrier-based migration assays under shear stress revealed that cell patches expanded their boundaries both along and against the flow, with greater distance in the direction of flow. Our system and findings may help lay the foundation for understanding biophysical regulation of developmental processes in a physiologically important, yet hard-to-access, epithelial model system.

{gamma}{delta} T-cells, which are predominantly enriched in epithelial tissues, have been used in cancer therapy because of their capacity for rapid cytotoxicity in an MHC-independent manner. Current paradigms are largely agnostic to the role of tissue mechanical cues in regulating {gamma}{delta} T-cell function. Here, we investigated the role of matrix viscoelasticity in modulating {gamma}{delta} T-cell migration, differentiation state, phenotype, and function. Using a tunable collagen-based gel system, we found that encapsulation in highly-elastic (slow-relaxing) matrices preserved a less differentiated phenotype, as evidenced by CD27 and CD45RA expression. Slow-relaxing matrices also increased expression of Fas and PD-1, while decreasing expression of CD11a. Despite increased PD-1 expression, these cells remained functional, as demonstrated by high levels of TNF- and IFN-{gamma} relative to PD-1-negative cells. Proteomic analysis revealed that {gamma}{delta} T-cells respond to changes in viscoelasticity through actin remodeling and shifts in metabolic machinery. Overall, when compared to non-encapsulated cells (2D culture), encapsulated {gamma}{delta} T-cells showed increased expression of cytotoxic programs. Functionally, cells encapsulated in slow-relaxing gels showed improved control of tumor growth in an aggressive HCT116 tumor model. Together, these findings establish matrix viscoelasticity as an important regulator of post-thymic {gamma}{delta} T-cell differentiation and function.

Nanoparticle drug delivery systems hold considerable promise for locoregional administration to central nervous system tumors, yet the biological determinants of nanoparticle-cancer cell interactions remain poorly understood. Using patient-derived histone-mutant diffuse midline glioma (DMG) models, we performed a pooled CRISPR-Cas9 perturbation screen to systematically identify regulators of liposomal nanoparticle delivery. The screen identified candidate genes spanning endocytosis, vesicle transport, and metabolic signaling, revealing that nanoparticle delivery is governed by a broader landscape than previously appreciated. Among these, CTNNB1, or {beta}-catenin, emerged as a common negative regulator across two independent DMG models and two distinct nanoparticle surface chemistries. Transcriptomic profiling of CTNNB1-depleted DMG cells revealed upregulation of membrane remodeling and extracellular matrix gene programs, accompanied by reduced cell stiffness measured by a microfluidic acoustic scattering assay. This resulted in a shift in endocytic activity characterized by decreased bulk-phase macropinocytosis and increased receptor-mediated endocytosis. We further identified MAPK and mTOR pathway members as nanoparticle trafficking modulators, and demonstrated concordance between genetic and pharmacologic perturbations in modulating the liposomal nanoparticle interactions in pediatric DMG cells. These findings establish a biology-first screening approach for identifying previously unappreciated regulators with potential relevance to nanoparticle-based therapeutic strategies in pediatric brain tumors.