Direct therapeutic effect of sulfadoxine-pyrimethamine on nutritional deficiency-induced enteric dysfunction in a human Intestine Chip.

BACKGROUND: Sulfadoxine-pyrimethamine (SP) antimalarial therapy has been suggested to potentially increase the birth weight of infants in pregnant women in sub-Saharan Africa, independently of malarial infection. Here, we utilized female intestinal organoid-derived cells cultured within microfluidic Organ Chips to investigate whether SP could directly impact intestinal function and thereby improve the absorption of essential fats and nutrients crucial for fetal growth. METHODS: Using a human organ-on-a-chip model, we replicated the adult female intestine with patient organoid-derived duodenal epithelial cells interfaced with human intestinal endothelial cells. Nutrient-deficient (ND) medium was perfused to simulate malnutrition, resulting in the appearance of enteric dysfunction indicators such as villus blunting, reduced mucus production, impaired nutrient absorption, and increased inflammatory cytokine secretion. SP was administered to these chips in the presence or absence of human peripheral blood mononuclear cells (PBMCs). FINDINGS: Our findings revealed that SP treatment effectively reversed multiple intestinal absorptive abnormalities observed in malnourished female Intestine Chips, as validated by transcriptomic and proteomic analyses. SP also reduced the production of inflammatory cytokines and suppressed the recruitment of PBMCs in ND chips. INTERPRETATION: Our results indicate that SP could potentially increase birth weights by preventing enteric dysfunction and suppressing intestinal inflammation. This underscores the potential of SP as a targeted intervention to improve maternal absorption, subsequently contributing to healthier fetal growth. While SP treatment shows promise in addressing malabsorption issues that can influence infant birth weight, we did not model pregnancy in our chips, and thus its usefulness for treatment of malnourished pregnant women requires further investigation through clinical trials. FUNDING: The Bill and Melinda Gates Foundation, and the Wyss Institute for Biologically Inspired Engineering at Harvard University, and the HDDC Organoid Core of the P30 DK034854.

Biology-inspired microphysiological systems to advance patient benefit and animal welfare in drug development

The first microfluidic microphysiological systems (MPS) entered the academic scene more than 15 years ago and were considered an enabling technology to human (patho)biology in vitro and, therefore, provide alternative approaches to laboratory animals in pharmaceutical drug development and academic research. Nowadays, the field generates more than a thousand scientific publications per year. Despite the MPS hype in academia and by platform providers, which says this technology is about to reshape the entire in vitro culture landscape in basic and applied research, MPS approaches have neither been widely adopted by the pharmaceutical industry yet nor reached regulated drug authorization processes at all. Here, 46 leading experts from all stakeholders - academia, MPS supplier industry, pharmaceutical and consumer products industries, and leading regulatory agencies - worldwide have analyzed existing challenges and hurdles along the MPS-based assay life cycle in a second workshop of this kind in June 2019. They identified that the level of qualification of MPS-based assays for a given context of use and a communication gap between stakeholders are the major challenges for industrial adoption by end-users. Finally, a regulatory acceptance dilemma exists against that background. This t4 report elaborates on these findings in detail and summarizes solutions how to overcome the roadblocks. It provides recommendations and a roadmap towards regulatory accepted MPS-based models and assays for patients' benefit and further laboratory animal reduction in drug development. Finally, experts highlighted the potential of MPS-based human disease models to feedback into laboratory animal replacement in basic life science research.

Hypoxia-enhanced Blood-Brain Barrier Chip recapitulates human barrier function and shuttling of drugs and antibodies.

The high selectivity of the human blood-brain barrier (BBB) restricts delivery of many pharmaceuticals and therapeutic antibodies to the central nervous system. Here, we describe an in vitro microfluidic organ-on-a-chip BBB model lined by induced pluripotent stem cell-derived human brain microvascular endothelium interfaced with primary human brain astrocytes and pericytes that recapitulates the high level of barrier function of the in vivo human BBB for at least one week in culture. The endothelium expresses high levels of tight junction proteins and functional efflux pumps, and it displays selective transcytosis of peptides and antibodies previously observed in vivo. Increased barrier functionality was accomplished using a developmentally-inspired induction protocol that includes a period of differentiation under hypoxic conditions. This enhanced BBB Chip may therefore represent a new in vitro tool for development and validation of delivery systems that transport drugs and therapeutic antibodies across the human BBB.

Human kidney proximal tubule-on-a-chip for drug transport and nephrotoxicity assessment.

Kidney toxicity is one of the most frequent adverse events reported during drug development. The lack of accurate predictive cell culture models and the unreliability of animal studies have created a need for better approaches to recapitulate kidney function in vitro. Here, we describe a microfluidic device lined by living human kidney epithelial cells exposed to fluidic flow that mimics key functions of the human kidney proximal tubule. Primary kidney epithelial cells isolated from human proximal tubule are cultured on the upper surface of an extracellular matrix-coated, porous, polyester membrane that splits the main channel of the device into two adjacent channels, thereby creating an apical 'luminal' channel and a basal 'interstitial' space. Exposure of the epithelial monolayer to an apical fluid shear stress (0.2 dyne cm(-2)) that mimics that found in living kidney tubules results in enhanced epithelial cell polarization and primary cilia formation compared to traditional Transwell culture systems. The cells also exhibited significantly greater albumin transport, glucose reabsorption, and brush border alkaline phosphatase activity. Importantly, cisplatin toxicity and Pgp efflux transporter activity measured on-chip more closely mimic the in vivo responses than results obtained with cells maintained under conventional culture conditions. While past studies have analyzed kidney tubular cells cultured under flow conditions in vitro, this is the first report of a toxicity study using primary human kidney proximal tubular epithelial cells in a microfluidic 'organ-on-a-chip' microdevice. The in vivo-like pathophysiology observed in this system suggests that it might serve as a useful tool for evaluating human-relevant renal toxicity in preclinical safety studies.

Tensegrity and mechanotransduction.

Anyone who is skilled in the art of physical therapy knows that the mechanical properties, behavior and movement of our bodies are as important for human health as chemicals and genes. However, only recently have scientists and physicians begun to appreciate the key role which mechanical forces play in biological control at the molecular and cellular levels. This article provides a brief overview of a lecture presented at the First International Fascia Research Congress that convened at Harvard Medical School in Boston, MA on October 4, 2007. In this lecture, I described what we have learned over the past 30 years as a result of our research focused on the molecular mechanisms by which cells sense mechanical forces and convert them into changes in intracellular biochemistry and gene expression-a process called "mechanotransduction". This work has revealed that molecules, cells, tissues, organs, and our entire bodies use "tensegrity" architecture to mechanically stabilize their shape, and to seamlessly integrate structure and function at all size scales. Through the use of this tension-dependent building system, mechanical forces applied at the macroscale produce changes in biochemistry and gene expression within individual living cells. This structure-based system provides a mechanistic basis to explain how application of physical therapies might influence cell and tissue physiology.