Purpose of Review: Human pancreas-on-a-chip (PoC) technology is quickly advancing as a platform for complex in vitro modeling of islet physiology. This review summarizes the current progress and evaluates the possibility of using this technology for clinical islet transplantation.Recent Findings: PoC microfluidic platforms have mainly shown proof of principle for long-term culturing of islets to study islet function in a standardized format. Advancement in microfluidic design by using imaging-compatible biomaterials and biosensor technology might provide a novel future tool for predicting islet transplantation outcome. Progress in combining islets with other tissue types gives a possibility to study diabetic interventions in a minimal equivalent in vitro environment.Summary: Although the field of PoC is still in its infancy, considerable progress in the development of functional systems has brought the technology on the verge of a general applicable tool that may be used to study islet quality and to replace animal testing in the development of diabetes interventions.

Polydimethylsiloxane (PDMS) has been used in microfluidic systems for years, as it can be easily structured and its flexibility makes it easy to integrate actuators including pneumatic pumps. In addition, the good optical properties of the material are well suited for analytical systems. In addition to its positive aspects, PDMS is well known to adsorb small molecules, which limits its usability when it comes to drug testing, e.g., in organ-on-a-chip (OoC) systems. Therefore, alternatives to PDMS are in high demand. In this study, we use thermoplastic elastomer (TPE) films thermally bonded to laser-cut poly(methyl methacrylate) (PMMA) sheets to build up multilayered microfluidic devices with integrated pneumatic micro-pumps. We present a low-cost manufacturing technology based on a conventional CO₂ laser cutter for structuring, a spin-coating process for TPE film fabrication, and a thermal bonding process using a pneumatic hot-press. UV treatment with an Excimer lamp prior to bonding drastically improves the bonding process. Optimized bonding parameters were characterized by measuring the burst load upon applying pressure and via profilometer-based measurement of channel deformation. Next, flow and long-term stability of the chip layout were measured using microparticle Image Velocimetry (uPIV). Finally, human endothelial cells were seeded in the microchannels to check biocompatibility and flow-directed cell alignment. The presented device is compatible with a real-time live-cell analysis system.

Organ-on-a-Chip (OoC) systems bring together cell biology, engineering, and material science for creating systems that recapitulate the in vivo microenvironment of tissues and organs. The versatility of OoC systems enables in vitro models for studying physiological processes, drug development, and testing in both academia and industry. This paper evaluates current platforms from the academic end-user perspective, elaborating on usability, complexity, and robustness. We surveyed 187 peers in 35 countries and grouped the responses according to preliminary knowledge and the source of the OoC systems that are used. The survey clearly shows that current commercial OoC platforms provide a substantial level of robustness and usability—which is also indicated by an increasing adaptation of the pharmaceutical industry—but a lack of complexity can challenge their use as a predictive platform. Self-made systems, on the other hand, are less robust and standardized but provide the opportunity to develop customized and more complex models, which are often needed for human disease modeling. This perspective serves as a guide for researchers in the OoC field and encourages the development of next-generation OoCs.

Type 2 diabetes mellitus (T2DM), obesity, and metabolic dysfunction‐associated steatotic liver disease (MASLD) are epidemiologically correlated disorders with a worldwide growing prevalence. While the mechanisms leading to the onset and development of these conditions are not fully understood, predictive tissue representations for studying the coordinated interactions between central organs that regulate energy metabolism, particularly the liver and pancreatic islets, are needed. Here, a dual pump‐less recirculating organ‐on‐chip platform that combines human pluripotent stem cell (sc)‐derived sc‐liver and sc‐islet organoids is presented. The platform reproduces key aspects of the metabolic cross‐talk between both organs, including glucose levels and selected hormones, and supports the viability and functionality of both sc‐islet and sc‐liver organoids while preserving a reduced release of pro‐inflammatory cytokines. In a model of metabolic disruption in response to treatment with high lipids and fructose, sc‐liver organoids exhibit hallmarks of steatosis and insulin resistance, while sc‐islets produce pro‐inflammatory cytokines on‐chip. Finally, the platform reproduces known effects of anti‐diabetic drugs on‐chip. Taken together, the platform provides a basis for functional studies of obesity, T2DM, and MASLD on‐chip, as well as for testing potential therapeutic interventions.

The catalytic enzymes tankyrase 1 and 2 (TNKS1/2) alter protein turnover by poly-ADP-ribosylating target proteins, which earmark them for degradation by the ubiquitin–proteasomal system. Prominent targets of the catalytic activity of TNKS1/2 include AXIN proteins, resulting in TNKS1/2 being attractive biotargets for addressing of oncogenic WNT/β-catenin signaling. Although several potent small molecules have been developed to inhibit TNKS1/2, there are currently no TNKS1/2 inhibitors available in clinical practice. The development of tankyrase inhibitors has mainly been disadvantaged by concerns over biotarget-dependent intestinal toxicity and a deficient therapeutic window. Here we show that the novel, potent, and selective 1,2,4-triazole–based TNKS1/2 inhibitor OM-153 reduces WNT/β-catenin signaling and tumor progression in COLO 320DM colon carcinoma xenografts upon oral administration of 0.33–10 mg/kg twice daily. In addition, OM-153 potentiates anti–programmed cell death protein 1 (anti–PD-1) immune checkpoint inhibition and antitumor effect in a B16-F10 mouse melanoma model. A 28-day repeated dose mouse toxicity study documents body weight loss, intestinal damage, and tubular damage in the kidney after oral–twice daily administration of 100 mg/kg. In contrast, mice treated oral–twice daily with 10 mg/kg show an intact intestinal architecture and no atypical histopathologic changes in other organs. In addition, clinical biochemistry and hematologic analyses do not identify changes indicating substantial toxicity. The results demonstrate OM-153–mediated antitumor effects and a therapeutic window in a colon carcinoma mouse model ranging from 0.33 to at least 10 mg/kg, and provide a framework for using OM-153 for further preclinical evaluations.Significance: This study uncovers the effectiveness and therapeutic window for a novel tankyrase inhibitor in mouse tumor models.

The placenta is a key embryonic structure that separates maternal and fetal blood systems. The barrier function of the human placenta is performed by villous trophoblasts, i.e. undifferentiated cytotrophoblasts and differentiated syncytiotrophoblats, whose maturation and function are influenced by wall shear stress (WSS) from the maternal blood circulation. Most in vitro placenta models rely on cyclic adenosine monophosphate inducer forskolin (FSK) to establish a placental syncytium. Here a trophoblastic BeWo cell line is used to systematically compare the effect of FSK treatment in static culture with WSS stimulation in a pumpless, recirculating organ‐on‐chip. It is shown that BeWo cells undergo a similar differentiation under WSS exposure to FSK treatment. A WSS of 0.1 dyn cm ⁻² leads to cell fusion, polarization, barrier functions, human chorionic gonadotropin (β‐hCG) secretion, and increased expression of key transporters. Moreover, WSS induces favorable changes in the levels of FMS‐like tyrosine kinase‐1 (FLT‐1) and Placental Growth Factor (PlGF) suggesting the development of a physiologically relevant placental syncytium‐on‐chip (PSoC) without the need for FSK. The platform is further expanded to a syncytiotrophoblast/endothelial co‐culture showing physiological vascular functions under WSS. The forskolin‐free PSoC presented here represents the first pumpless recirculating and scalable platform for physiological placental studies and drug testing.