Biology subjects

Loskill, P.

Publications and source records attributed to Loskill, P..

15 recordsLinked to original sources

bioRxiv2026

Ovarian cancer-on-chip for patient-specific profiling of treatment responses to sequential chemotherapy and PD-L1 blockade

BackgroundOvarian cancer (OvCa) ranks as the most lethal gynecological malignancy in women worldwide. This complex disease, which can develop independently of a womans age, is characterized by late diagnosis, pronounced tumor heterogeneity, and an immunosuppressive tumor microenvironment (TME). Incremental diagnostic tools that could better inform clinicians on potential therapy resistance or subsets of patients that could benefit from new drug modalities represent a critical unmet need to improve patient care and potentially the identification of new biomarkers. ObjectiveThis study aimed to establish a reconfigurable patient-derived OvCa-on-chip platform for longitudinal functional profiling of tumor cell death, immune activation, and patient-specific responses to TIL-mediated killing, PD-L1 blockade, and sequential chemo-immunotherapy. MethodsPatient-derived OvCa microtumors (PDM) were integrated with sequential integration of autologous tumor-infiltrating lymphocytes (TILs) into a perfusable microfluidic chip in the presence of different single and combination treatment regimens of chemotherapy and immune checkpoint inhibitors (ICIs). Treatment responses were assessed by longitudinal quantification of caspase-cleaved cytokeratin 18 (ccCK18) as marker of apoptotic epithelial tumor cell death, as well as cytokine/chemokine release in chip effluents, and multiplex flow cytometry-based characterization of autologous TIL subsets. ResultsThe perfusable OvCa-on-chip platform supported long-term culture of PDM while maintaining key structural and microenvironmental features of the primary tumor. Multidimensional analyses, including time-resolved assessment of tumor cell death, secretome profiling and correlative analysis of autologous TIL subsets revealed patient-specific tumor-immune response patterns and heterogenous sensitivity to TIL-mediated killing, PD-L1 blockade, and sequential chemo-immunotherapy. Correlation analyses identified treatment-dependent associations between specific TIL phenotypes and functional tumor cell killing. PD-1-expressing CD4 TIL subsets correlated with enhanced tumor cell killing, whereas terminally exhausted CD8PD-1Tcf1- TILs negatively correlated with durvalumab responses. In contrast, tumor-reactive CD8CD39 TILs were associated with improved responses under sequential chemo-immunotherapy conditions. ConclusionCollectively, this OvCa-on-chip system represents a complex in vitro model (CIVM) that combines 3D tumor tissue with autologous immune cells in a microfluidic platform. Resembling a physiologically relevant human preclinical platform, it allows for the time-resolved functional assessment of patient-specific responsiveness to OvCa therapies, with direct implications for personalized treatment stratification.

cancer biology↗

bioRxiv2026

A scalable mesh microelectrode array platform for longitudinal electrophysiology in neural spheroids

Electrophysiological interfacing remains difficult in three-dimensional in vitro models, when using planar microelectrode arrays or optical methods. This challenge limits experimental progress using such models, despite their promise of better physiological relevance than monolayer cell culture. Mesh MEAs which can integrate conformally on or even within tissue offer a possible solution but are not yet widely accessible. Here, we present a mesh MEA device, designed as a simple, manufacturable platform for spheroid electrophysiology. In neural spheroids, the device enabled longitudinal electrophysiological recordings and pharmacological modulation of spontaneous electrical activity. On native polyimide meshes, spheroids maintained their shape while cells enveloped the mesh, embedding electrodes to a depth of 100 {micro}m after 2 weeks. In contrast, laminin biofunctionalization of the mesh promoted outgrowth and migration of cells. This device and associated methods should be adaptable to organoids, ex vivo tissue, or bioengineered in vitro models.

neuroscience↗

bioRxiv2026

Functional primary human 3D skeletal muscle organoids enable exercise and metabolic research

Human skeletal muscle is the principal site of insulin-stimulated glucose disposal and a major mediator of exercise-induced metabolic benefits, yet human models that preserve metabolic and exercise responsiveness remain limited. We generated primary human skeletal muscle organoids from donor-derived CD56+ myoblasts using a collagen-based extracellular matrix and serum-free IGF1-guided differentiation. The organoids formed aligned contractile tissues containing oxidative and glycolytic fiber type-like myotubes, displayed enhanced mitochondrial respiration, insulin-stimulated glucose uptake, and reproducible force generation. Electrical pulse stimulation induced AMPK activation, increased glucose utilization and lactate production, and upregulated canonical exercise-responsive genes including NR4A3 and PPARGC1A. Notably, transcriptional responses to in vitro exercise overlapped with acute exercise responses observed in skeletal muscle biopsies from the same donors. The organoids further detected functional impairments of skeletal muscle performance induced by TGF-{beta}1 and metformin and increased speed generation by testosterone treatment. These findings establish a donor-specific human skeletal muscle platform that recapitulates key features of insulin action and exercise adaptation and may enable mechanistic studies of skeletal muscle metabolism, exercise responsiveness, and therapeutic interventions relevant to diabetes.

Molecular Biology↗

bioRxiv2025

Lymphoid-tissue-on-chip recapitulates human antibody responses in vitro

In the past decades, vaccine development has made great strides. Nevertheless, more often than not, vaccine candidates fail in advanced stages of development and clinical trials. A key reason is the poor predictive value of non-clinical in vivo and in vitro models, due to either species-specific differences in the immune response or insufficient reflection of physiological vaccine mechanisms. Reliable modeling of human adaptive immune responses is a prerequisite to understand processes leading to vaccine-induced protective immunization and to drive informed decisions in vaccine development pipelines. Here, we present a centrifugal microfluidics based organ-on-chip approach to generate an organotypic high density lymphoid tissue on-chip. The model enables long-term culture of lymphoid tissue and raised antigen-specific antibody responses against influenza vaccines even after four weeks on-chip. Antibody response of different magnitude and quality could be induced both by direct antigen exposure as well as by recruitment of antigen-presenting cells from the periphery. The model represents an attractive approach to evaluate the impact of the mode of antigen delivery on adaptive immune responses. Beyond applications in vaccine development, the lymphoid-tissue-on-chip provides a platform to study cellular interactions during homeostasis, immune responses and long-term impact of immunomodulators over several weeks.

bioengineering↗

bioRxiv2023

Cancer-mediated Axonal Guidance of Sensory Neurons in a Microelectrode-based Innervation MPS

Despite recent advances in the field of microphysiological systems (MPS), availability of models capable of mimicking the interactions between the nervous system and innervated tissues is still limited. This represents a significant challenge in identifying the underlying processes of various pathological conditions, including neuropathic, cardiovascular and metabolic disorders. In this study, we introduce a compartmentalized 3D coculture system that enables physiologically relevant tissue innervation while recording neuronal excitability. By integrating custom microelectrode arrays into tailored glass chips microfabricated via selective laser-etching, we developed an entirely novel class of innervation MPSs (INV-MPS). This INV-MPS allows for manipulation, visualization, and electrophysiological analysis of individual axons innervating complex 3D tissues. Here, we focused on sensory innervation of 3D tumor tissue as a model case study since cancer-induced pain represents a major unmet medical need. The system was compared with existing nociception models and successfully replicated axonal chemoattraction mediated by nerve growth factor (NGF). Remarkably, in the absence of NGF, 3D cancer spheroids cocultured in the adjacent compartment induced sensory neurons to consistently cross the separating barrier and establish fine innervation. Moreover, we observed that crossing sensory fibers could be chemically excited by distal application of known pain-inducing agonists only when cocultured with cancer cells. To our knowledge, this is the first system showcasing morphological and electrophysiological analysis of 3D-innervated tumor tissue in vitro, paving the way for a plethora of studies into innervation-related diseases and improving our understanding of underlying pathophysiology. Significance StatementMPSs integrating innervated tissues are crucial as alternatives to animal models and to enhance the translation of non-clinical research to humans, as nerve fibers play a pivotal role in many organs. To address this need, we developed the INV-MPS, enabling parallelized electro-physiological recording from 3D cocultures of peripheral neurons with complex tissues. We demonstrate the ability of cancer spheroids to direct axonal growth and modulate excitability of nociceptive fibers in a 3D setting. We anticipate that this model will be applicable for closely monitoring innervation in various tissues, including somatic and visceral organs. The INV-MPS, hence, has tremendous potential for human-relevant drug discovery, creating opportunities for more ethical and clinically translatable approaches to study innervation in disease.

neuroscience↗

bioRxiv2023

Solid tumor-on-chip model for efficacy and safety assessment of CAR-T cell therapy

The non-clinical assessment of CAR-T cells demands innovative models that are capable of predicting safety and efficacy in the clinical setting. Here, we present a novel solid tumor-on-chip model that allows CAR-T cell perfusion and integrates the vasculature and tumor lesions to recapitulate key events of CAR-T cell performance including extravasation, tumor infiltration and cytokine release. We assessed CAR-T cells targeting the ROR1 antigen against tumor aggregates that were derived from a breast cancer cell line and primary breast cancer organoids. The data show the temporal kinetic of ROR1 CAR-T cell migration and expansion, lytic activity and cytokine production over the course of 8 days, and reveal a correlation between anti-tumor efficacy and ROR1 antigen density on tumor cells. CAR-modified T cells extravasated faster, infiltrated tumor lesions stronger, persisted longer and in higher numbers than non-CAR modified T cells. Intriguingly, we detected cytokine release levels and kinetics typically observed in patients who developed cytokine release syndrome, and administered dasatinib as a pharmacologic OFF switch to control this inflammatory response. The data illustrate the ability of this tumor-on-chip platform to assess parameters associated withherapeutic outcome and the potential to aid in patient stratification and monitoring of CAR-T cell therapy.

bioengineering↗

bioRxiv2023

Engineering of human myotubes toward a mature metabolic and contractile phenotype

1.Skeletal muscle mediates the beneficial effects of exercise, thereby improving insulin sensitivity and reducing the risk for type 2 diabetes. Current human skeletal muscle models in vitro are incapable of fully recapitulating its physiological functions especially muscle contractility. By supplementation of insulin-like growth factor 1 (IGF1), a growth factor secreted by myofibers in vivo, we aimed to overcome these limitations. We monitored the differentiation process starting from primary human CD56-positive myoblasts in the presence/absence of IGF1 in serum-free medium in daily collected samples for 10 days. IGF1-supported differentiation formed thicker multinucleated myotubes showing physiological contraction upon electrical pulse stimulation following day 6. Myotubes without IGF1 were almost incapable of contraction. IGF1-treatment shifted the proteome toward skeletal muscle-specific proteins that contribute to myofibril and sarcomere assembly, striated muscle contraction, and ATP production. Elevated PPARGC1A, MYH7 and reduced MYH1/2 suggest a more oxidative phenotype further demonstrated by higher abundance of proteins of the respiratory chain and elevated mitochondrial respiration. IGF1-treatment also upregulated GLUT4 and increased insulin-dependent glucose uptake compared to myotubes differentiated without IGF1. To conclude, utilizing IGF1, we engineered human myotubes that recapitulate the physiological traits of skeletal muscle in vivo superior to established protocols and overcome limitations of previous standards. This novel "easy to use" model enables investigation of exercise on a molecular level. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=85 SRC="FIGDIR/small/544344v3_ufig1.gif" ALT="Figure 1"> View larger version (22K): org.highwire.dtl.DTLVardef@be17b5org.highwire.dtl.DTLVardef@6a2d2org.highwire.dtl.DTLVardef@1abbd52org.highwire.dtl.DTLVardef@1a721f_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

bioRxiv2022

Training the next generation of researchers in the Organ-on-Chip field

Organ-on-chip (OoC) technology bridges the principles of biology and engineering to create a new generation of in vitro models and involves highly interdisciplinary collaboration across STEM disciplines. Training the next generation of scientists, technicians and policy makers is a challenge that requires a tailored effort. To promote the qualification, usability, uptake and long-term development of OoC technology, we designed a questionnaire to evaluate the key aspects for training, identify the major stakeholders to be trained, their professional level and specific skillset. The 151 respondents unanimously agreed on the need to train the next generation of OoC researchers and that the training should be provided early, in interdisciplinary subjects and throughout the researchers career. We identified two key training priorities: (i) training scientists with a biology background in microfabrication and microfluidics principles and (ii) training OoC developers in pharmacology/toxicology. This makes training in OoC a transdisciplinary challenge rather than an interdisciplinary one. The data acquired and analyzed here serves to guide training initiatives for preparing competent and transdisciplinary researchers, capable of assuring the successful development and application of OoC technologies in academic research, pharmaceutical/chemical/cosmetic industries, personalized medicine and clinical trials on chip.

scientific communication and education↗

bioRxiv2022

Fusing spheroids to aligned μ-tissues in a Heart-on-Chip featuring oxygen sensing and electrical pacing capabilities

Over the last decade Organ-on-Chip (OOC) emerged as a promising technology for advanced in vitro models, recapitulating key physiological cues. OOC approaches tailored for cardiac tissue engineering resulted in a variety of platforms, some of which integrate stimulation or probing capabilities. Due to manual handling processes, however, a large-scale standardized and robust tissue generation, applicable in an industrial setting, is still out of reach. Here, we present a novel cell injection and tissue generation concept relying on spheroids, which can be produced in large quantities and uniform size from induced pluripotent stem cell-derived human cardiomyocytes. Hydrostatic flow transports and accumulates spheroids in dogbone-shaped cultivation chambers, which subsequently fuse and form aligned, contracting cardiac muscle fibers. Furthermore, we demonstrate electrical stimulation capabilities by utilizing fluidic media connectors as electrodes and provide the blueprint of a low-cost, open-source, scriptable pulse generator. We report on a novel integration strategy of optical O2 sensor spots into resin-based microfluidic systems, enabling in situ determination of O2 partial pressures. Finally, proof-of-concept demonstrating electrical stimulation combined with in situ monitoring of metabolic activity in cardiac tissues is provided. The developed system thus opens the door for advanced OOCs integrating biophysical stimulation as well as probing capabilities and serves as blueprint for the facile and robust generation of high density microtissues in microfluidic modules amenable for scale-up and automation.

bioengineering↗

bioRxiv2021

Aged human iPSC-RPE organoid cultures display hallmarks of drusen formation

Age-related macular degeneration (AMD) is among the most common causes of irreversible vision loss. Disease progression is strongly associated with age-related pathological changes of retinal pigment epithelial (RPE) cells, such as accumulation of intracellular lipid-containing cell debris, extracellular lipid-rich deposits (drusen) and collagen-rich basal laminar deposits. Current AMD models provide a limited understanding of the complex pathomechanisms, revealing the lack of adequate physiological human AMD models. In this study, we developed an in vitro model applicable for the exploration of AMD pathomechanisms and risk factors for AMD progression and drusen formation. Advanced 3D culturing technologies allow long-term cultivation of hiPSC-derived RPE organoids (RPEorg) for up to 360 days, which is the time frame necessary for the development of an AMD-like phenotype. Aged RPEorg exhibit hallmarks of AMD and age-related alterations such as increased autofluorescence, accumulation of lipid droplets, calcification, and the formation of extracellular clusters of the drusen-associated proteins such as apolipoprotein E (APOE) and tissue inhibitor of metalloproteinases 3 (TIMP3). Electron microscopy further reveals drusen-like extracellular deposits mimicking the signs of late drusen formation and AMD progression. In summary, our results demonstrate that hiPSC-derived 3D RPEorg provide a promising model to study age-associated RPE pathology and drusen formation. We show here that RPEorg are applicable for disease modelling studies and early stages of drug development and provide the opportunity to uncover inter-individual genetic and epigenetic factors that alter the course of the disease.

cell biology↗

bioRxiv2021

Autologous human immunocompetent white adipose tissue-on-chip

Obesity and associated diseases, such as diabetes, have reached epidemic proportions globally. In the era of diabesity and due to its central role for metabolic and endocrine processes, adipose tissue (specifically white adipose tissue; WAT) has become a target of high interest for therapeutic strategies. To gain insights in cellular and molecular mechanisms of adipose (patho-)physiology, researchers traditionally relied on animal models since in vitro studies on human WAT are challenging due to the large size, buoyancy, and fragility of mature white adipocytes. Leveraging the Organ-on-Chip technology, we introduce a next-generation microphysiological in vitro model of human WAT based on a tailored microfluidic platform featuring vasculature-like perfusion. The platform integrates a 3D tissue comprising all major WAT-associated cellular components in an autologous manner, including not only mature adipocytes but also organotypic endothelial barriers and stromovascular cells featuring tissue-resident innate immune cells, specifically adipose tissue macrophages. This microphysiological tissue model recapitulates pivotal WAT functions, such as energy storage and mobilization as well as endocrine and immunomodulatory activities. The combination of all individual cell types with extra cellular matrix-like hydrogels in a precisely controllable bottom-up approach enables the generation of a multitude of replicates from the same donors circumventing issues of inter-donor variability and paving the way for personalized medicine. Moreover, it allows to adjust the models degree of complexity to fit a specific purpose via a flexible mix- and-match approach with different cell component modules. This novel WAT-on-chip system constitutes a human-based, autologous and immunocompetent in vitro model of adipose tissue that recapitulates almost full tissue heterogeneity. In the future, the new WAT-on-chip model can become a powerful tool for human-relevant research in the field of metabolism and its associated diseases as well as for compound testing and personalized- and precision medicine applications.

bioengineering↗

bioRxiv2021

Human immunocompetent Choroid-on-Chip: a novel tool for studying ocular effects of biological drugs

Disorders of the eye leading to visual impairment are a major issue that affects millions of people. On the other side ocular toxicities were described for e.g. molecularly targeted therapies in oncology and may hamper their development. Current ocular model systems feature a number of limitations affecting human-relevance and availability. To find new options for pharmacological treatment and assess mechanisms of toxicity, hence, novel complex model systems that are human-relevant and readily available are urgently required. Here, we report the development of a human immunocompetent Choroid-on-Chip (CoC), a human cell-based in vitro model of the choroid layer of the eye integrating melanocytes and microvascular endothelial cells, covered by a layer of retinal pigmented epithelial cells. Immunocompetence is achieved by perfusion of peripheral immune cells. We demonstrate controlled immune cell recruitment into the stromal compartments through a vascular monolayer and in vivo-like cytokine release profiles. To investigate applicability for both efficacy testing of immunosuppressive compounds as well as safety profiling of immunoactivating antibodies, we exposed the CoCs to cyclosporine and tested CD3 bispecific antibodies. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=96 SRC="FIGDIR/small/443846v1_ufig1.gif" ALT="Figure 1"> View larger version (40K): org.highwire.dtl.DTLVardef@506402org.highwire.dtl.DTLVardef@1d5cdd3org.highwire.dtl.DTLVardef@1bc09d3org.highwire.dtl.DTLVardef@2909de_HPS_FORMAT_FIGEXP M_FIG Graphical Abstract C_FIG

bioengineering↗

bioRxiv2021

Human stem cell-based retina-on-chip as new translational model for validation of AAV retinal gene therapy vectors

Gene therapies using adeno-associated viruses (AAVs) are amongst the most promising strategies to treat or even cure hereditary and acquired retinal diseases. However, the development of new efficient AAV vectors is slow and costly, largely because of the lack of suitable non-clinical models. By faithfully recreating structure and function of human tissues, human induced pluripotent stem cell (iPSC)-derived retinal organoids could become an essential part of the test cascade addressing translational aspects. Organ-on-Chip (OoC) technology further provides the capability to recapitulate microphysiological tissue environments as well as a precise control over structural and temporal parameters. By employing our recently developed Retina-on-chip that merges organoid and OoC-technology, we analyzed the efficacy, kinetics and cell tropism of seven first and second generation AAV vectors. The presented data demonstrate the potential of iPSC-based OoC models as the next generation of screening platforms for future gene therapeutic studies.

bioengineering↗

bioRxiv2019

WAT’s up!? – Organ-on-a-chip integrating human mature white adipose tissues for mechanistic research and pharmaceutical applications

Obesity and its numerous adverse health consequences have taken on global, pandemic proportions. White adipose tissue (WAT) - a key contributor in many metabolic diseases - contributes about one fourth of a healthy humans body mass. Despite its significance, many WAT-related pathophysiogical mechanisms in humans are still not understood, largely due to the reliance on non-human animal models. In recent years, Organ-on-a-chip (OoC) platforms have developed into promising alternatives for animal models; these systems integrate engineered human tissues into physiological microenvironment supplied by a vasculature-like microfluidic perfusion. Here, we report the development of a novel OoC that integrates functional mature human WAT. The WAT-on-a-chip is a multilayer device that features tissue chambers tailored specifically for the maintenance of 3D tissues based on human primary adipocytes, with supporting nourishment provided through perfused media channels. The platforms capability to maintain long-term viability and functionality of WAT was confirmed by real-time monitoring of fatty acid uptake, by quantification of metabolite release into the effluent media as well as by an intact responsiveness to a therapeutic compound. The novel system provides a promising tool for wide-ranging applications in mechanistic research of WAT-related biology, in studying of pathophysiological mechanisms in obesity and diabetes, and in R&D of pharmaceutical industry.

bioengineering↗

bioRxiv2019

Human Retina-on-a-Chip: Merging Organoid and Organ-on-a-Chip Technology to Generate Complex Multi-Layer Tissue Models

The devastating effects and incurable nature of hereditary and sporadic retinal diseases such as Stargardt disease, age-related macular degeneration or retinitis pigmentosa urgently require the development of new therapeutic strategies. Additionally, the prevalence of retinal toxicities is becoming more and more an issue of novel targeted therapeutic agents. To date, (ophthalmologic) drug development largely relies on animal models. Inadequate translatability of results from animal models to humans, however, limits advances in drug development and discovery. Hence, the establishment of more relevant human tissue-based in vitro models is of upmost importance. The discovery of self-forming retinal organoids (ROs) derived from human embryonic stem cells (hESCs) or human induced pluripotent stem cells (hiPSCs) is a promising approach to model the complex stratified retinal tissue. Yet, ROs lack vascularization and cannot recapitulate the important physiological interactions of matured photoreceptors and the retinal pigment epithelium (RPE). In this study, we present the retina-on-a-chip (RoC), a novel microphysiological model of the human retina integrating more than seven different essential retinal cell types derived from hiPSCs in a vasculature-like perfusion and enabling, for the first time, the recapitulation of the interaction of mature photoreceptor segments with RPE in vitro. We show that this interaction enhances the formation of outer segment like-structures and the establishment of in vivo-like physiological processes such as outer segment phagocytosis and calcium dynamics. In addition, we demonstrate the applicability of the RoC for drug testing, by reproducing the retinopathic side effects of the anti-malaria drug chloroquine and the antibiotic gentamicin. The developed hiPSC-based RoC has the potential to promote drug development and provide new insights into the underlying pathology of retinal diseases.

bioengineering↗