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Human microphysiological systems: Tissues-on-chips for in vitro safety, toxicity and efficacy testing
S44
Abstracts / Toxicology Letters 259S (2016) S4–S62
Objective: The aim of this study is to develop an in vitro TBI-on a chip model using the different cell types that constitute the NVU. Materials and methods: The TBI-on-a-chip will be composed by a PDMS chip on top of a silicone membrane; the different cells that form the NVU will be plated on top of the membrane. Deformation due to uniaxial high-speed stretch (HSS) will be achieved by moving a linear actuator to produce 0, 5, 10 and 15% deformation of the membranes. Live/dead staining, LDH release, caspase 3/7 staining, nitric oxide (NO) production and protein analysis will be valuated 24 h after a single stretch injury. Results: We will discuss the challenges on the design of the TBI on a chip model. The results of cellular, molecular and biochemical analysis and the similarities and differences between our TBI on a chip system with in vivo models will be discussed. Conclusion: Upon complete validation, the TBI on a chip system has the potential to be used as a model to study drugs for the treatment of TBI. Financial support: NCTR Protocol E7584.01. http://dx.doi.org/10.1016/j.toxlet.2016.07.688 S24-2 Organ-on chip systems to evaluate functional cardiovascular toxicity J. Morales ∗ , K. Balachandran Department of Biomedical Engineering, University of Arkansas, Fayetteville, AR, USA Introduction: While methods to evaluate biological toxicity are very prevalent, funcitonal assessments are limited. This paper is divided into two separate studies. In the first study, we studied the functional toxicity of radiation therapy on cardiac myocytes. In the second stufy, we explored the role of serotonin and angiotensin exposure on cardiac valve interstitial cells. Objective: The overall objective of this study was to utilize an organ-on-chip contractility assay to monitor functional cardiovascular toxicity of cardiac myocytes and cardiac valve interstitial cells. Materials and methods: We developed a polymer thin filmbased drug contractility assay. We utilized this assay to probe for alterations in cellular contractility and mechanical tone of cardiac myocytes and cardiac valve interstitial cells (VICs) due to potential pathologic stimuli. Aligned cellular two-dimensional celular monolayers were constructed on a detachable polydimethylsiloxane (PDMS) membrane using micropatterning. The cells formed a distinct monolayer of about 3 m thickness. The thin films (vTF) were manually cut out in a Tyrode’s solution bath. Cardiac myocytes that had undergone radiation therapy (0, 0.1, 1 and 10 Gy) were paced at 0.5, 1 and 2 Hz and monitored. Cardiac valve interstitial cells were subject to different doses of serotonin and angiotensin and had their contractility probed with endothelin-1. Results: Results indicated that cardiac contractility was significantly reduced due to radiation in a dose-dependent manner only 24 h after radiation treatment. Cardiac VICs were exposed to serotonin (10−8 or 10−7 M) and angiotensin-II (5 and 100 nM) as well as a combination. We observed that the combination treatment resulted in increased VIC contractility and basal tone, correlating with increased remodeling in the VIC. Conclusions: Our study demonstrates the utility of the thin film organ-on-chip approach for studying cardiovascular functional toxicity under diverse stimuli. These approaches can potentially complement traditional biological methods for detecting celular toxicity due to pathological reagents.
Financial support: We thank the Arkansas Biosciences Institute for financial Support. http://dx.doi.org/10.1016/j.toxlet.2016.07.689 S24-3 Human microphysiological systems: Tissues-on-chips for in vitro safety, toxicity and efficacy testing D.A. Tagle Associate Director for Special Initiatives, National Center for Advancing Translational Sciences, National Institutes of Health, USA Advances in basic and preclinical science continue to fuel the drug discovery pipeline, however only a small fraction of compounds meet criteria for approval by the FDA. More than 30% of promising medications have failed in human clinical trials because they are determined to be toxic despite promising pre-clinical studies in 2-D cell culture and animal models, and another 60% fail due to lack of efficacy. The challenge of accurately predicting drug toxicities and efficacies is in part due to inherent species differences in drug metabolizing enzyme activities and cell-type specific sensitivities to toxicants. To address this challenge in drug development and regulatory science, the NIH in partnership with DARPA, FDA, and more recently the pharmaceutical industry has invested in the Tissues-on-Chips program to develop alternative approaches that would enable early indications and potentially more reliable readouts of toxicity and efficacy. The goal of the tissue-on-chips program is to develop bio-engineered microdevices that represent functional units of the 10 major human organ systems: circulatory, respiratory, integumentary, reproductive, endocrine, gastrointestinal, nervous, urinary, musculoskeletal, and immune. The opportunities for significant advancements in the prediction of human response to drug toxicities through the development of microphysiological systems, requires a multi-disciplinary approach that relies on an understanding of human physiology and anatomy, stem cell biology, microfluidics, material sciences and bioengineering. Since the inception of this program in 2012, several unique and novel in vitro platforms have demonstrated human organotypic physiological functions and relevant response to drug exposure ensuring that safe and effective therapeutics are identified sooner, and ineffective or toxic ones are rejected early in the drug development process. These microfabricated devices have also proven to be useful for modeling human diseases and may prove to be sufficient alternatives to the use of animal testing. It is anticipated that the availability of these systems to the broader research community will foster a multitude of new research applications including, but not limited to studies in precision medicine, environment exposures, reproduction and development, infectious diseases, cancer, countermeasures for chemical warfare, immune responses and neuro-inflammation. http://dx.doi.org/10.1016/j.toxlet.2016.07.690
Abstracts / Toxicology Letters 259S (2016) S4–S62
Objective: The aim of this study is to develop an in vitro TBI-on a chip model using the different cell types that constitute the NVU. Materials and methods: The TBI-on-a-chip will be composed by a PDMS chip on top of a silicone membrane; the different cells that form the NVU will be plated on top of the membrane. Deformation due to uniaxial high-speed stretch (HSS) will be achieved by moving a linear actuator to produce 0, 5, 10 and 15% deformation of the membranes. Live/dead staining, LDH release, caspase 3/7 staining, nitric oxide (NO) production and protein analysis will be valuated 24 h after a single stretch injury. Results: We will discuss the challenges on the design of the TBI on a chip model. The results of cellular, molecular and biochemical analysis and the similarities and differences between our TBI on a chip system with in vivo models will be discussed. Conclusion: Upon complete validation, the TBI on a chip system has the potential to be used as a model to study drugs for the treatment of TBI. Financial support: NCTR Protocol E7584.01. http://dx.doi.org/10.1016/j.toxlet.2016.07.688 S24-2 Organ-on chip systems to evaluate functional cardiovascular toxicity J. Morales ∗ , K. Balachandran Department of Biomedical Engineering, University of Arkansas, Fayetteville, AR, USA Introduction: While methods to evaluate biological toxicity are very prevalent, funcitonal assessments are limited. This paper is divided into two separate studies. In the first study, we studied the functional toxicity of radiation therapy on cardiac myocytes. In the second stufy, we explored the role of serotonin and angiotensin exposure on cardiac valve interstitial cells. Objective: The overall objective of this study was to utilize an organ-on-chip contractility assay to monitor functional cardiovascular toxicity of cardiac myocytes and cardiac valve interstitial cells. Materials and methods: We developed a polymer thin filmbased drug contractility assay. We utilized this assay to probe for alterations in cellular contractility and mechanical tone of cardiac myocytes and cardiac valve interstitial cells (VICs) due to potential pathologic stimuli. Aligned cellular two-dimensional celular monolayers were constructed on a detachable polydimethylsiloxane (PDMS) membrane using micropatterning. The cells formed a distinct monolayer of about 3 m thickness. The thin films (vTF) were manually cut out in a Tyrode’s solution bath. Cardiac myocytes that had undergone radiation therapy (0, 0.1, 1 and 10 Gy) were paced at 0.5, 1 and 2 Hz and monitored. Cardiac valve interstitial cells were subject to different doses of serotonin and angiotensin and had their contractility probed with endothelin-1. Results: Results indicated that cardiac contractility was significantly reduced due to radiation in a dose-dependent manner only 24 h after radiation treatment. Cardiac VICs were exposed to serotonin (10−8 or 10−7 M) and angiotensin-II (5 and 100 nM) as well as a combination. We observed that the combination treatment resulted in increased VIC contractility and basal tone, correlating with increased remodeling in the VIC. Conclusions: Our study demonstrates the utility of the thin film organ-on-chip approach for studying cardiovascular functional toxicity under diverse stimuli. These approaches can potentially complement traditional biological methods for detecting celular toxicity due to pathological reagents.
Financial support: We thank the Arkansas Biosciences Institute for financial Support. http://dx.doi.org/10.1016/j.toxlet.2016.07.689 S24-3 Human microphysiological systems: Tissues-on-chips for in vitro safety, toxicity and efficacy testing D.A. Tagle Associate Director for Special Initiatives, National Center for Advancing Translational Sciences, National Institutes of Health, USA Advances in basic and preclinical science continue to fuel the drug discovery pipeline, however only a small fraction of compounds meet criteria for approval by the FDA. More than 30% of promising medications have failed in human clinical trials because they are determined to be toxic despite promising pre-clinical studies in 2-D cell culture and animal models, and another 60% fail due to lack of efficacy. The challenge of accurately predicting drug toxicities and efficacies is in part due to inherent species differences in drug metabolizing enzyme activities and cell-type specific sensitivities to toxicants. To address this challenge in drug development and regulatory science, the NIH in partnership with DARPA, FDA, and more recently the pharmaceutical industry has invested in the Tissues-on-Chips program to develop alternative approaches that would enable early indications and potentially more reliable readouts of toxicity and efficacy. The goal of the tissue-on-chips program is to develop bio-engineered microdevices that represent functional units of the 10 major human organ systems: circulatory, respiratory, integumentary, reproductive, endocrine, gastrointestinal, nervous, urinary, musculoskeletal, and immune. The opportunities for significant advancements in the prediction of human response to drug toxicities through the development of microphysiological systems, requires a multi-disciplinary approach that relies on an understanding of human physiology and anatomy, stem cell biology, microfluidics, material sciences and bioengineering. Since the inception of this program in 2012, several unique and novel in vitro platforms have demonstrated human organotypic physiological functions and relevant response to drug exposure ensuring that safe and effective therapeutics are identified sooner, and ineffective or toxic ones are rejected early in the drug development process. These microfabricated devices have also proven to be useful for modeling human diseases and may prove to be sufficient alternatives to the use of animal testing. It is anticipated that the availability of these systems to the broader research community will foster a multitude of new research applications including, but not limited to studies in precision medicine, environment exposures, reproduction and development, infectious diseases, cancer, countermeasures for chemical warfare, immune responses and neuro-inflammation. http://dx.doi.org/10.1016/j.toxlet.2016.07.690