Publications by authors named "James J Hickman"

92 Publications

A Human-Based Functional NMJ System for Personalized ALS Modeling and Drug Testing.

Adv Ther (Weinh) 2020 Nov 11;3(11). Epub 2020 Aug 11.

NanoScience Technology Center, University of Central Florida, 12424 Research Parkway, Suite 400, Orlando, FL 32826, USA.

Loss of the neuromuscular junction (NMJ) is an early and critical hallmark in all forms of ALS. The study design was to develop a functional NMJ disease model by integrating motoneurons (MNs) differentiated from multiple ALS-patients' induced pluripotent stem cells (iPSCs) and primary human muscle into a chambered system. NMJ functionality was tested by recording myotube contractions while stimulating MNs by field electrodes and a set of clinically relevant parameters were defined to characterize the NMJ function. Three ALS lines were analyzed, 2 with SOD1 mutations and 1 with a FUS mutation. The ALS-MNs reproduced pathological phenotypes, including increased axonal varicosities, reduced axonal branching and elongation and increased excitability. These MNs formed functional NMJs with wild type muscle, but with significant deficits in NMJ quantity, fidelity and fatigue index. Furthermore, treatment with the Deana protocol was found to correct the NMJ deficits in all the ALS mutant lines tested. Quantitative analysis also revealed the variations inherent in each mutant lines. This functional NMJ system provides a platform for the study of both fALS and sALS and has the capability of being adapted into subtype-specific or patient-specific models for ALS etiological investigation and patient stratification for drug testing.
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http://dx.doi.org/10.1002/adtp.202000133DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7942691PMC
November 2020

Characterization of Drug-Polymer Adsorption Isotherms in Body-on-a-Chip Systems by Inverse Liquid-Solid Chromatography.

ACS Biomater Sci Eng 2020 08 8;6(8):4462-4475. Epub 2020 Jul 8.

NanoScience Technology Center, University of Central Florida, 12424 Research Parkway, Suite 400, Orlando, Florida 32826, United States.

Body-on-a-chip and human-on-a-chip systems are currently being used to augment and could eventually replace animal models in drug discovery and basic biological research. However, hydrophobic molecules, especially therapeutic compounds, tend to adsorb to the polymer materials used to create these microfluidic platforms, which may distort the dose-response curves that feed into pharmacokinetic/pharmacodynamic (PK/PD) models, which translate preclinical data into predictions of clinical outcomes. Inverse liquid-solid chromatography paired with a numerical optimization based on the Langmuir model of adsorption was used to characterize the adsorption isotherm parameters of drugs to polydimethylsiloxane (PDMS) and polymethylmethacrylate (PMMA), polymers commonly used in these platforms. The adsorption isotherms were then compared against concentration measurements of drugs recirculated in these platforms. This research further illustrates the point that by quantifying drug or drug candidate interactions before system dosing and including this data in the PK/PD models, then polymers used in these platforms need not be limited to "less-adsorbing" materials.
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http://dx.doi.org/10.1021/acsbiomaterials.0c00350DOI Listing
August 2020

Characterization of Functional Human Skeletal Myotubes and Neuromuscular Junction Derived-From the Same Induced Pluripotent Stem Cell Source.

Bioengineering (Basel) 2020 Oct 22;7(4). Epub 2020 Oct 22.

NanoScience Technology Center, University of Central Florida, 12424 Research Parkway, Suite 400, Orlando, FL 32826, USA.

In vitro generation of functional neuromuscular junctions (NMJs) utilizing the same induced pluripotent stem cell (iPSC) source for muscle and motoneurons would be of great value for disease modeling and tissue engineering. Although, differentiation and characterization of iPSC-derived motoneurons are well established, and iPSC-derived skeletal muscle (iPSC-SKM) has been reported, there is a general lack of systemic and functional characterization of the iPSC-SKM. This study performed a systematic characterization of iPSC-SKM differentiated using a serum-free, small molecule-directed protocol. Morphologically, the iPSC-SKM demonstrated the expression and appropriate distribution of acetylcholine, ryanodine and dihydropyridine receptors. Fiber type analysis revealed a mixture of human fast (Type IIX, IIA) and slow (Type I) muscle types and the absence of animal Type IIB fibers. Functionally, the iPSC-SKMs contracted synchronously upon electrical stimulation, with the contraction force comparable to myofibers derived from primary myoblasts. Most importantly, when co-cultured with human iPSC-derived motoneurons from the same iPSC source, the myofibers contracted in response to motoneuron stimulation indicating the formation of functional NMJs. By demonstrating comparable structural and functional capacity to primary myoblast-derived myofibers, this defined, iPSC-SKM system, as well as the personal NMJ system, has applications for patient-specific drug testing and investigation of muscle physiology and disease.
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http://dx.doi.org/10.3390/bioengineering7040133DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7712960PMC
October 2020

Functional skeletal muscle model derived from SOD1-mutant ALS patient iPSCs recapitulates hallmarks of disease progression.

Sci Rep 2020 08 31;10(1):14302. Epub 2020 Aug 31.

NanoScience Technology Center, University of Central Florida, 12424 Research Parkway, Suite 400, Orlando, FL, 32826, USA.

Recent findings suggest a pathologic role of skeletal muscle in amyotrophic lateral sclerosis (ALS) onset and progression. However, the exact mechanism by which this occurs remains elusive due to limited human-based studies. To this end, phenotypic ALS skeletal muscle models were developed from induced pluripotent stem cells (iPSCs) derived from healthy individuals (WT) and ALS patients harboring mutations in the superoxide dismutase 1 (SOD1) gene. Although proliferative, SOD1 myoblasts demonstrated delayed and reduced fusion efficiency compared to WT. Additionally, SOD1 myotubes exhibited significantly reduced length and cross-section. Also, SOD1 myotubes had loosely arranged myosin heavy chain and reduced acetylcholine receptor expression per immunocytochemical analysis. Functional analysis indicated considerably reduced contractile force and synchrony in SOD1 myotubes. Mitochondrial assessment indicated reduced inner mitochondrial membrane potential (ΔΨm) and metabolic plasticity in the SOD1-iPSC derived myotubes. This work presents the first well-characterized in vitro iPSC-derived muscle model that demonstrates SOD1 toxicity effects on human muscle regeneration, contractility and metabolic function in ALS. Current findings align with previous ALS patient biopsy studies and suggest an active contribution of skeletal muscle in NMJ dysfunction. Further, the results validate this model as a human-relevant platform for ALS research and drug discovery studies.
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http://dx.doi.org/10.1038/s41598-020-70510-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7459299PMC
August 2020

A functional long-term 2D serum-free human hepatic in vitro system for drug evaluation.

Biotechnol Prog 2021 Jan 3;37(1):e3069. Epub 2020 Oct 3.

NanoScience Technology Center, University of Central Florida, Orlando, Florida, USA.

Human in vitro hepatic models generate faster drug toxicity data with higher human predictability compared to animal models. However, for long-term studies, current models require the use of serum and 3D architecture, limiting their utility. Maintaining a functional long-term human in vitro hepatic culture that avoids complex structures and serum would improve the value of such systems for preclinical studies. This would also enable a more straightforward integration with current multi-organ devices to study human systemic toxicity to generate an alternative model to chronic animal evaluations. A human primary hepatocyte culture system was characterized for 28 days in 2D and serum-free defined conditions. Under the studied conditions, human primary hepatocytes maintained their characteristic morphology, hepatic markers and functions for 28 days. The acute and chronic administration of known drugs validated the sensitivity of the system for drug testing. This human 2D model represents a realistic system to evaluate hepatic function for long-term drug studies, without the need of animal serum, confounding variable in most models, and with less complexity and resultant cost compared to most 3D models. The defined culture conditions can easily be integrated into complex multi-organ in vitro models for studying systemic effects driven by the liver function for long-term evaluations.
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http://dx.doi.org/10.1002/btpr.3069DOI Listing
January 2021

Myelination and Node of Ranvier Formation in a Human Motoneuron-Schwann Cell Serum-Free Coculture.

ACS Chem Neurosci 2020 09 18;11(17):2615-2623. Epub 2020 Aug 18.

NanoScience Technology Center, University of Central Florida, 12424 Research Parkway, Suite 400, Orlando, Florida 32826, United States.

Myelination and node of Ranvier formation play an important role in the rapid conduction of nerve impulses, referred to as saltatory conduction, along axons in the peripheral nervous system. We report a human-human myelination model using human primary Schwann cells (SCs) and human-induced pluripotent stem-cell-derived motoneurons utilizing a serum-free medium supplemented with ascorbate to induce myelination, where 41.6% of SCs expressed the master transcription factor for myelination, early growth response protein 2. After 30 days in coculture, myelin segments were visualized using immunocytochemistry for myelin basic protein surrounding neurofilament-stained motor neuron axons, which was confirmed via 3D confocal Raman microscopy, a viable alternative for transmission electron microscopy analysis. The myelination efficiency was 65%, and clusters of voltage-gated sodium channels and the paranodal protein contactin-associated protein 1 indicated node of Ranvier formation. This model has applications to study remyelination and demyelinating diseases, including Charcot-Marie Tooth disorder, Guillian-Barre syndrome, and anti-myelin-associated glycoprotein peripheral neuropathy.
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http://dx.doi.org/10.1021/acschemneuro.0c00287DOI Listing
September 2020

Differential Monocyte Actuation in a Three-Organ Functional Innate Immune System-on-a-Chip.

Adv Sci (Weinh) 2020 Jul 2;7(13):2000323. Epub 2020 Jun 2.

Hesperos, Inc. 12501 Research Parkway, Suite 100 Orlando FL 32826 USA.

A functional, human, multiorgan, pumpless, immune system-on-a-chip featuring recirculating THP-1 immune cells with cardiomyocytes, skeletal muscle, and liver in separate compartments in a serum-free medium is developed. This in vitro platform can emulate both a targeted immune response to tissue-specific damage, and holistic proinflammatory immune response to proinflammatory compound exposure. The targeted response features fluorescently labeled THP-1 monocytes selectively infiltrating into an amiodarone-damaged cardiac module and changes in contractile force measurements without immune-activated damage to the other organ modules. In contrast to the targeted immune response, general proinflammatory treatment of immune human-on-a-chip systems with lipopolysaccharide (LPS) and interferon- (IFN-) causes nonselective damage to cells in all three-organ compartments. Biomarker analysis indicates upregulation of the proinflammation cytokines TNF-, IL-6, IL-10, MIP-1, MCP-1, and RANTES in response to LPS + IFN- treatment indicative of the M1 macrophage phenotype, whereas amiodarone treatment only leads to an increase in the restorative cytokine IL-6 which is a marker for the M2 phenotype. This system can be used as an alternative to humanized animal models to determine direct immunological effects of biological therapeutics including monoclonal antibodies, vaccines, and gene therapies, and the indirect effects caused by cytokine release from target tissues in response to a drug's pharmacokinetics (PK)/pharmacodynamics (PD) profile.
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http://dx.doi.org/10.1002/advs.202000323DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7341107PMC
July 2020

Inverse liquid-solid chromatography to evaluate drug interactions with organosilane-modified polydimethylsiloxane for use in body-on-a-chip systems.

Biotechnol Prog 2020 11 18;36(6):e3048. Epub 2020 Aug 18.

NanoScience Technology Center, University of Central Florida, Orlando, Florida, USA.

Body-on-a-chip and organ-on-a-chip systems utilize polydimethylsiloxane (PDMS) because of the relative suitability of the material for fabrication of microfluidic channels and chambers used in these devices. However, hydrophobic molecules, especially therapeutic compounds, tend to adsorb to PDMS, which may distort the dose-response curves that feed into the pharmacokinetic/pharmacodynamic models used to translate preclinical data into predictions of clinical outcomes. Surface modification by organosilanes is one method being explored to modify PDMS, but the effect of organosilanes on drug adsorption isotherms is not well characterized. We utilized Inverse Liquid-Solid Chromatography to characterize the adsorption parameters of the drugs acetaminophen, diclofenac, and verapamil with native PDMS and organosilane-modified (fluoropolymer (13F) and polyethylene glycol) PDMS surfaces, to correlate the modifications with changes in drug adsorption. It was determined that the organosilane modifications significantly changed the energy of adsorption of the test drug utilizing our methodology.
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http://dx.doi.org/10.1002/btpr.3048DOI Listing
November 2020

A human induced pluripotent stem cell-derived cortical neuron human-on-a chip system to study Aβ and tau-induced pathophysiological effects on long-term potentiation.

Alzheimers Dement (N Y) 2020 27;6(1):e12029. Epub 2020 May 27.

NanoScience Technology Center University of Central Florida Orlando Florida USA.

Introduction: The quest to identify an effective therapeutic strategy for neurodegenerative diseases, such as mild congitive impairment (MCI) and Alzheimer's disease (AD), suffers from the lack of good human-based models. Animals represent the most common models used in basic research and drug discovery studies. However, safe and effective compounds identified in animal studies often translate poorly to humans, yielding unsuccessful clinical trials.

Methods: A functional in vitro assay based on long-term potentiation (LTP) was used to demonstrate that exposure to amyloid beta (Aβ) and tau oligomers, or brain extracts from AD transgenic mice led to prominent changes in human induced pluripotent stem cells (hiPSC)-derived cortical neurons, notably, without cell death.

Results: Impaired information processing was demonstrated by treatment of neuron-MEA (microelectrode array) systems with the oligomers and brain extracts by reducing the effects of LTP induction. These data confirm the neurotoxicity of molecules linked to AD pathology and indicate the utility of this human-based system to model aspects of AD in vitro and study LTP deficits without loss of viability; a phenotype that more closely models the preclinical or early stage of AD.

Discussion: In this study, by combining multiple relevant and important molecular and technical aspects of neuroscience research, we generated a new, fully human in vitro system to model and study AD at the preclinical stage. This system can serve as a novel drug discovery platform to identify compounds that rescue or alleviate the initial neuronal deficits caused by Aβ and/or tau oligomers, a main focus of clinical trials.
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http://dx.doi.org/10.1002/trc2.12029DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7253154PMC
May 2020

Differentiation of Intrafusal Fibers from Human Induced Pluripotent Stem Cells.

ACS Chem Neurosci 2020 04 19;11(7):1085-1092. Epub 2020 Mar 19.

Hybrid Systems Lab, NanoScience Technology Center, University of Central Florida, 12424 Research Parkway, Suite 400, Orlando, Florida 32826, United States.

Human-based "body-on-a-chip" technology provides powerful platforms in developing models for drug evaluation and disease evaluations in phenotypic models. Induced pluripotent stem cells (iPSCs) are ideal cell sources for generating different cell types for these functional systems and recapitulation of the neuromuscular reflex arc would allow for the study of patient specific neuromuscular diseases. Regarding relevant afferent (intrafusal fibers, sensory neurons) and efferent (extrafusal fibers, motoneurons) cells, differentiation of intrafusal fiber from human iPSCs has not been established. This work demonstrates a protocol for inducing an enrichment of intrafusal bag fibers from iPSCs using morphological analysis and immunocytochemistry. Phosphorylation of the ErbB2 receptors and S46 staining indicated a 3-fold increase of total intrafusal fibers further confirming the efficiency of the protocol. Integration of induced intrafusal fibers would enable more accurate reflex arc models and application of this protocol on patient iPSCs would allow for patient-specific disease modeling.
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http://dx.doi.org/10.1021/acschemneuro.0c00055DOI Listing
April 2020

Microphysiological heart-liver body-on-a-chip system with a skin mimic for evaluating topical drug delivery.

Lab Chip 2020 02 23;20(4):749-759. Epub 2020 Jan 23.

NanoScience Technology Center, University of Central Florida, Orlando, FL 32826, USA. and Hesperos, Inc., Orlando, FL 32826, USA.

Body-on-a-chip in vitro systems are a promising technology that aims to increase the predictive power of drug efficacy and toxicity in humans when compared to traditional animal models. Here, we developed a new heart-liver body-on-a-chip system with a skin surrogate to assess the toxicity of drugs that are topically administered. In order to test the utility of the system, diclofenac, ketoconazole, hydrocortisone and acetaminophen were applied topically through a synthetic skin surrogate (Strat-M membrane) and the toxicity results were compared to those of acute drug exposure from systemically applying the compounds. The heart-liver system was successful in predicting the effects for both cardiac and liver functions changes due to the compounds. The difference in the concentrations of drugs applied topically compared to systemically indicates that the barrier properties of the skin surrogate were efficient. One important advantage of this heart-liver system was the capability of showing differential effects of acute and chronic drug exposure which is necessary as part of the International Conference in Harmonisation (ICH) tri-partate guidelines. In conclusion, this work indicates a promising heart-liver body-on-a-chip system that can be used for the assessment of potential drug toxicity from dermal absorption as well as evaluate transport dynamics through the skin in the same system.
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http://dx.doi.org/10.1039/c9lc00861fDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7123528PMC
February 2020

Piezoelectric BioMEMS Cantilever for Measurement of Muscle Contraction and for Actuation of Mechanosensitive Cells.

MRS Commun 2019 Dec 20;9(4):1186-1192. Epub 2019 Sep 20.

Hybrid Systems Laboratory, University of Central Florida, NanoScience Technology Center, 12424 Research Parkway, Suite 400, Orlando, FL 32826.

A piezoelectric biomedical microelectromechanical system (bioMEMS) cantilever device was designed and fabricated to act as either a sensing element for muscle tissue contraction or as an actuator to apply mechanical force to cells. The sensing ability of the piezoelectric cantilevers was shown by monitoring the electrical signal generated from the piezoelectric aluminum nitride in response to the contraction of iPSC-derived cardiomyocytes cultured on the piezoelectric cantilevers. Actuation was demonstrated by applying electrical pulses to the piezoelectric cantilever and observing bending via an optical detection method. This piezoelectric cantilever device was designed to be incorporated into body-on-a-chip systems.
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http://dx.doi.org/10.1557/mrc.2019.129DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7995331PMC
December 2019

A multiplexed in vitro assay system for evaluating human skeletal muscle functionality in response to drug treatment.

Biotechnol Bioeng 2020 03 13;117(3):736-747. Epub 2019 Dec 13.

NanoScience Technology Center, University of Central Florida, Orlando, Florida.

In vitro systems that mimic organ functionality have become increasingly important tools in drug development studies. Systems that measure the functional properties of skeletal muscle are beneficial to compound screening studies and also for integration into multiorgan devices. To date, no studies have investigated human skeletal muscle responses to drug treatments at the single myotube level in vitro. This report details a microscale cantilever chip-based assay system for culturing individual human myotubes. The cantilevers, along with a laser and photo-detector system, enable measurement of myotube contractions in response to broad-field electrical stimulation. This system was used to obtain baseline functional parameters for untreated human myotubes, including peak contractile force and time-to-fatigue data. The cultured myotubes were then treated with known myotoxic compounds and the resulting functional changes were compared to baseline measurements as well as known physiological responses in vivo. The collected data demonstrate the system's capacity for screening direct effects of compound action on individual human skeletal myotubes in a reliable, reproducible, and noninvasive manner. Furthermore, it has the potential to be utilized for high-content screening, disease modeling, and exercise studies of human skeletal muscle performance utilizing iPSCs derived from specific patient populations such as the muscular dystrophies.
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http://dx.doi.org/10.1002/bit.27231DOI Listing
March 2020

Microphysiological systems.

APL Bioeng 2019 Dec 29;3(4):040401. Epub 2019 Oct 29.

Department of Biological Engineering and Department of Mechanical Engineering, Massachusetts Institute of Technology, 500 Technology Square, MIT Building, Room NE47-321, Cambridge, Massachusetts 02139, USA.

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http://dx.doi.org/10.1063/1.5130170DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6819166PMC
December 2019

Temporal Characterization of Neuronal Migration Behavior on Chemically Patterned Neuronal Circuits in a Defined Environment.

ACS Biomater Sci Eng 2018 Oct 27;4(10):3460-3470. Epub 2018 Aug 27.

NanoScience Technology Center, University of Central Florida, 12424 Research Parkway, Suite 400, Orlando, Florida 32826, United States.

Directed control of neuronal migration, facilitating the correct spatial positioning of neurons, is crucial to the development of a functional nervous system. An understanding of neuronal migration and positioning on patterned surfaces would also be beneficial for investigators seeking to design culture platforms capable of mimicking the complex functional architectures of neuronal tissues for drug development as well as basic biomedical research applications. This study used coplanar self-assembled monolayer patterns of cytophilic, -1[3-(trimethoxysilyly)propyl] diethylenetriamine (DETA) and cytophobic, tridecafluoro-1,1,2,2-tetrahydrooctyl-1-trichlorosilane (13F) to assess the migratory behavior and physiological characteristics of cultured neurons. Analysis of time-lapse microscopy data revealed a dynamic procedure underlying the controlled migration of neurons, in response to extrinsic geometric and chemical cues, to promote the formation of distinct two-neuron circuits. Immunocytochemical characterization of the neurons highlights the organization of actin filaments (phalloidin) and microtubules (β-tubulin) at each migration stage. These data have applications in the development of precise artificial neuronal networks and provide a platform for investigating neuronal migration as well as neurite identification in differentiating cultured neurons. Importantly, the cytoskeletal arrangement of these cells identifies a specific mode of neuronal migration on these  surfaces characterized by a single process determining the direction of cell migration and mimicking somal translocation behavior . Such information provides valuable additional insight into the mechanisms controlling neuronal development and maturation and validates the biochemical mechanisms underlying this behavior as representative of neuronal positioning phenomena .
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http://dx.doi.org/10.1021/acsbiomaterials.8b00610DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6713422PMC
October 2018

A human platform for the evaluation of pharmacology strategies in cardiac ischemia.

APL Bioeng 2019 Sep 13;3(3):036103. Epub 2019 Aug 13.

NanoScience Technology Center, University of Central Florida, 12424 Research Parkway Suite 400, Orlando, Florida 32826, USA.

Cardiac ischemic events increase the risk for arrhythmia, heart attack, heart failure, and death and are the leading mortality condition globally. Reperfusion therapy is the first line of treatment for this condition, and although it significantly reduces mortality, cardiac ischemia remains a significant threat. New therapeutic strategies are under investigation to improve the ischemia survival rate; however, the current preclinical models to validate these fail to predict the human outcome. We report the development of a functional human cardiac system for the study of conduction velocity under ischemic conditions. The system is a bioMEMs platform formed by human iPSC derived cardiomyocytes patterned on microelectrode arrays and maintained in serum-free conditions. Electrical activity changes of conduction velocity, beat frequency, and QT interval (the QT-interval measures the period from onset of depolarization to the completion of repolarization) or action potential length can be evaluated over time and under the stress of ischemia. The optimized protocol induces >80% reduction in conduction velocity, after a 4 h depletion period, and a partial recovery after 72 h of oxygen and nutrient reintroduction. The sensitivity of the platform for pharmacological interventions was challenged with a gap junction modulator (ZP1609), known to prevent or delay the depression of conduction velocity induced by ischemic metabolic stress. ZP1609 significantly improved the drastic drop in conduction velocity and enabled a greater recovery. This model represents a new preclinical platform for studying cardiac ischemia with human cells, which does not rely on biomarker analysis and has the potential for screening novel cardioprotective drugs with readouts that are closer to the measured clinical parameters.
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http://dx.doi.org/10.1063/1.5089237DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6692160PMC
September 2019

A human-on-a-chip approach to tackling rare diseases.

Drug Discov Today 2019 11 11;24(11):2139-2151. Epub 2019 Aug 11.

NanoScience Technology Center, University of Central Florida, Orlando, FL 32826, USA; Hesperos, Inc., Orlando, FL 32826, USA. Electronic address:

Drug development for rare diseases, classified as diseases with a prevalence of < 200 000 patients, is limited by the high cost of research and low target population. Owing to a lack of representative disease models, research has been challenging for orphan drugs. Human-on-a-chip (HoaC) technology, which models human tissues in interconnected in vitro microfluidic devices, has the potential to lower the cost of preclinical studies and increase the rate of drug approval by introducing human phenotypic models early in the drug discovery process. Advances in HoaC technology can drive a new approach to rare disease research and orphan drug development.
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http://dx.doi.org/10.1016/j.drudis.2019.08.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6856435PMC
November 2019

On the potential of in vitro organ-chip models to define temporal pharmacokinetic-pharmacodynamic relationships.

Sci Rep 2019 07 3;9(1):9619. Epub 2019 Jul 3.

Drug Safety and Metabolism, IMED Biotech Unit, AstraZeneca, Cambridge, UK.

Functional human-on-a-chip systems hold great promise to enable quantitative translation to in vivo outcomes. Here, we explored this concept using a pumpless heart only and heart:liver system to evaluate the temporal pharmacokinetic/pharmacodynamic (PKPD) relationship for terfenadine. There was a time dependent drug-induced increase in field potential duration in the cardiac compartment in response to terfenadine and that response was modulated using a metabolically competent liver module that converted terfenadine to fexofenadine. Using this data, a mathematical model was developed to predict the effect of terfenadine in preclinical species. Developing confidence that microphysiological models could have a transformative effect on drug discovery, we also tested a previously discovered proprietary AstraZeneca small molecule and correctly determined the cardiotoxic response to its metabolite in the heart:liver system. Overall our findings serve as a guiding principle to future investigations of temporal concentration response relationships in these innovative in vitro models, especially, if validated across multiple time frames, with additional pharmacological mechanisms and molecules representing a broad chemical diversity.
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http://dx.doi.org/10.1038/s41598-019-45656-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6610665PMC
July 2019

Multi-organ system for the evaluation of efficacy and off-target toxicity of anticancer therapeutics.

Sci Transl Med 2019 06;11(497)

Hesperos Inc., 3259 Progress Drive, Room 158, Orlando, FL 32826, USA.

A pumpless, reconfigurable, multi-organ-on-a-chip system containing recirculating serum-free medium can be used to predict preclinical on-target efficacy, metabolic conversion, and measurement of off-target toxicity of drugs using functional biological microelectromechanical systems. In the first configuration of the system, primary human hepatocytes were cultured with two cancer-derived human bone marrow cell lines for antileukemia drug analysis in which diclofenac and imatinib demonstrated a cytostatic effect on bone marrow cancer proliferation. Liver viability was not affected by imatinib; however, diclofenac reduced liver viability by 30%. The second configuration housed a multidrug-resistant vulva cancer line, a non-multidrug-resistant breast cancer line, primary hepatocytes, and induced pluripotent stem cell-derived cardiomyocytes. Tamoxifen reduced viability of the breast cancer cells only after metabolite generation but did not affect the vulva cancer cells except when coadministered with verapamil, a permeability glycoprotein inhibitor. Both tamoxifen alone and coadministration with verapamil produced off-target cardiac effects as indicated by a reduction of contractile force, beat frequency, and conduction velocity but did not affect viability. These systems demonstrate the utility of a human cell-based in vitro culture system to evaluate both on-target efficacy and off-target toxicity for parent drugs and their metabolites; these systems can augment and reduce the use of animals and increase the efficiency of drug evaluations in preclinical studies.
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http://dx.doi.org/10.1126/scitranslmed.aav1386DOI Listing
June 2019

Polarity Induced in Human Stem Cell Derived Motoneurons on Patterned Self-Assembled Monolayers.

ACS Chem Neurosci 2019 06 22;10(6):2756-2764. Epub 2019 May 22.

Hybrid Systems Lab, NanoScience Technology Center , University of Central Florida , 12424 Research Parkway, Suite 400 , Orlando , Florida 32826 , United States.

The control of polarized human neurite/axon development at the single neuron level is critical in geographically directing signal propagation in engineered neural networks, for both in vitro and in vivo applications. While there is an increasing need to exert control over axonal growth for the successful development and establishment of integrative and functional in vitro systems, controlled, polarized distribution of either human-derived neurons or motoneurons in vitro has yet to be reported. In this study, we established the polarized distribution of stem cell derived human motoneurons, using a patterned surface, and maintained the cells in a serum-free system. A surface pattern with defined polarity was developed using self-assembled monolayers (SAMs). A cell permissive SAM, DETA (trimethoxysilyl propyldiethylenetri-amine), combined with photolithography and a nonpermissive fluorinated silane, 13F (tridecafluoro-1,1,2,2-tetrahydroctyl-1-dimethylchloro-silane), generated a surface where neurons only adhered to the designed attachment sites and did so with preferred orientation. In addition, 75% of the cells attached to the patterns were motoneurons compared to their percentage in the standard unpatterned surface which was used as a control condition (20%), demonstrating the preference of these human motoneurons in adhering to the patterns. The ability to dictate the distribution and polarity of human motoneurons will be essential to the engineering of human-based functional in vitro systems in which the control of signal propagation is necessary but more importantly for cell implantation studies. Such systems will greatly benefit the study of motor function as well as aid the development of high-throughput systems for drug screening and test beds for use in preclinical studies related to conditions such as spinal cord injury, ALS, and muscular dystrophy.
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http://dx.doi.org/10.1021/acschemneuro.8b00682DOI Listing
June 2019

Evaluation of Holistic Treatment for ALS Reveals Possible Mechanism and Therapeutic Potential.

Int J Pharm Pharm Res 2017 Dec 30;11(1):348-374. Epub 2017 Dec 30.

NanoScience Technology Center, University of Central Florida, 12424 Research Parkway, Suite 400, Orlando, FL 32826.

There has been a tremendous amount of research into the causes of Amyotrophic Lateral Sclerosis (ALS), but yet very few treatment options beyond amelioration of symptoms. A holistic approach has shown anecdotal evidence of slowing disease progression and this treatment, known as the Deanna protocol (DP), postulates that ALS is a metabolic disease caused by glutamate that induces toxicity. In this study, glutamate exposure to human motoneurons was investigated and found not to significantly affect cell viability or electrophysiological properties. However, varicosities were observed in axons suggestive of transport impairment that was dose dependent for glutamate exposure. Surprisingly, a subset of the components of the DP eliminated these varicosities. To verify this finding a human SOD1 patient-derived iPSC line was examined and significant numbers of varicosities were present without glutamate treatment, compared to the iPSC control, indicating the possibility of a common mechanism despite different origins for the varicosities. Importantly, the DP ameliorated these varicosities by over 70% in the patient derived cells as well. These results are consistent with much of the literature on ALS and give hope for treatment not only for arresting disease progression using compounds considered safe but also the potential for restoration of function.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6326589PMC
December 2017

Ion channel dysfunction and altered motoneuron excitability in ALS.

Neurol Disord Epilepsy J 2019 30;3(2). Epub 2019 Jul 30.

Hybrid Systems Lab, NanoScience Technology Center, University of Central Florida, 12424, Research Parkway, Suite 400, Orlando, FL 32826, USA.

Dysregulated excitability is a hallmark of Amyotrophic Lateral Sclerosis (ALS) pathology both in ALS research models and in clinical settings. This primarily results from the dysfunction of Na, K, and Ca ion channels responsible for maintaining neuronal thresholds and executing signal transduction or synaptic transmission. The exact dysfunction that each of these ion channel currents display in ALS pathology can vary between different ALS models, mainly induced pluripotent stem cell (iPSC) derived human motoneurons and ALS mouse models. Moreover, results can vary further across ALS mutations and between different developmental periods of these disease models. This review attempts to gather observations regarding ion channel dysfunction contributing to both hyperexcitable and hypoexcitable phenotypes in ALS motoneurons both and , so as to assess their potential as therapeutic targets.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7170321PMC
July 2019

Recent Advances in Body-on-a-Chip Systems.

Anal Chem 2019 01 11;91(1):330-351. Epub 2018 Dec 11.

Nancy E. and Peter C. Meinig School of Biomedical Engineering , Cornell University , Ithaca , New York 14853 , United States.

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http://dx.doi.org/10.1021/acs.analchem.8b05293DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6687466PMC
January 2019

Investigation of the effect of hepatic metabolism on off-target cardiotoxicity in a multi-organ human-on-a-chip system.

Biomaterials 2018 11 4;182:176-190. Epub 2018 Aug 4.

NanoScience Technology Center, University of Central Florida, 12424 Research Parkway Suite 400, Orlando, FL 32826, USA. Electronic address:

Regulation of cosmetic testing and poor predictivity of preclinical drug studies has spurred efforts to develop new methods for systemic toxicity. Current in vitro assays do not fully represent physiology, often lacking xenobiotic metabolism. Functional human multi-organ systems containing iPSC derived cardiomyocytes and primary hepatocytes were maintained under flow using a low-volume pumpless system in a serum-free medium. The functional readouts for contractile force and electrical conductivity enabled the non-invasive study of cardiac function. The presence of the hepatocytes in the system induced cardiotoxic effects from cyclophosphamide and reduced them for terfenadine due to drug metabolism, as expected from each compound's pharmacology. A computational fluid dynamics simulation enabled the prediction of terfenadine-fexofenadine pharmacokinetics, which was validated by HPLC-MS. This in vitro platform recapitulates primary aspects of the in vivo crosstalk between heart and liver and enables pharmacological studies, involving both organs in a single in vitro platform. The system enables non-invasive readouts of cardiotoxicity of drugs and their metabolites. Hepatotoxicity can also be evaluated by biomarker analysis and change in metabolic function. Integration of metabolic function in toxicology models can improve adverse effects prediction in preclinical studies and this system could also be used for chronic studies as well.
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http://dx.doi.org/10.1016/j.biomaterials.2018.07.062DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6126670PMC
November 2018

Physiological Aβ Concentrations Produce a More Biomimetic Representation of the Alzheimer's Disease Phenotype in iPSC Derived Human Neurons.

ACS Chem Neurosci 2018 07 22;9(7):1693-1701. Epub 2018 May 22.

NanoScience Technology Center , University of Central Florida , 12424 Research Parkway, Suite 400 , Orlando , Florida 32826 United States.

Alzheimer's disease (AD) is characterized by slow, progressive neurodegeneration leading to severe neurological impairment, but current drug development efforts are limited by the lack of robust, human-based disease models. Amyloid-β (Aβ) is known to play an integral role in AD progression as it has been shown to interfere with neurological function. However, studies into AD pathology commonly apply Aβ to neurons for short durations at nonphysiological concentrations to induce an exaggerated dysfunctional phenotype. Such methods are unlikely to elucidate early stage disease dysfunction, when treatment is still possible, since damage to neurons by these high concentrations is extensive. In this study, we investigated chronic, pathologically relevant Aβ oligomer concentrations to induce an electrophysiological phenotype that is more representative of early AD progression compared to an acute high-dose application in human cortical neurons. The high, acute oligomer dose resulted in severe neuronal toxicity as well as upregulation of tau and phosphorylated tau. Chronic, low-dose treatment produced significant functional impairment without increased cell death or accumulation of tau protein. This in vitro phenotype more closely mirrors the status of early stage neural decline in AD pathology and could provide a valuable tool to further understanding of early stage AD pathophysiology and for screening potential therapeutic compounds.
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http://dx.doi.org/10.1021/acschemneuro.8b00067DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6051921PMC
July 2018

Stem cell derived phenotypic human neuromuscular junction model for dose response evaluation of therapeutics.

Biomaterials 2018 06 27;166:64-78. Epub 2018 Feb 27.

Hybrid Systems Lab, NanoScience Technology Center, University of Central Florida, 12424 Research Parkway, Suite 400, Orlando, FL 32826, USA. Electronic address:

There are currently no functional neuromuscular junction (hNMJ) systems composed of human cells that could be used for drug evaluations or toxicity testing in vitro. These systems are needed to evaluate NMJs for diseases such as amyotrophic lateral sclerosis, spinal muscular atrophy or other neurodegenerative diseases or injury states. There are certainly no model systems, animal or human, that allows for isolated treatment of motoneurons or muscle capable of generating dose response curves to evaluate pharmacological activity of these highly specialized functional units. A system was developed in which human myotubes and motoneurons derived from stem cells were cultured in a serum-free medium in a BioMEMS construct. The system is composed of two chambers linked by microtunnels to enable axonal outgrowth to the muscle chamber that allows separate stimulation of each component and physiological NMJ function and MN stimulated tetanus. The muscle's contractions, induced by motoneuron activation or direct electrical stimulation, were monitored by image subtraction video recording for both frequency and amplitude. Bungarotoxin, BOTOX and curare dose response curves were generated to demonstrate pharmacological relevance of the phenotypic screening device. This quantifiable functional hNMJ system establishes a platform for generating patient-specific NMJ models by including patient-derived iPSCs.
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http://dx.doi.org/10.1016/j.biomaterials.2018.02.047DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5866791PMC
June 2018

Comparison of NMDA and AMPA Channel Expression and Function between Embryonic and Adult Neurons Utilizing Microelectrode Array Systems.

ACS Biomater Sci Eng 2017 Dec 13;3(12):3525-3533. Epub 2017 Nov 13.

NanoScience Technology Center, University of Central Florida, 12424 Research Parkway, Orlando, Florida 32826, United States.

Microelectrode arrays (MEAs) are innovative tools used to perform electrophysiological experiments for the study of electrical activity and connectivity in populations of neurons from dissociated cultures. Reliance upon neurons derived from embryonic tissue is a common limitation of neuronal/MEA hybrid systems and perhaps of neuroscience research in general, and the use of adult neurons could model fully functional in vivo parameters more closely. Spontaneous network activity was concurrently recorded from both embryonic and adult rat neurons cultured on MEAs for up to 10 weeks in vitro to characterize the synaptic connections between cell types. The cultures were exposed to synaptic transmission antagonists against NMDA and AMPA channels, which revealed significantly different receptor profiles of adult and embryonic networks in vitro. In addition, both embryonic and adult neurons were evaluated for NMDA and AMPA channel subunit expression over five weeks in vitro. The results established that neurons derived from embryonic tissue did not express mature synaptic channels for several weeks in vitro under defined conditions. Consequently, the embryonic response to synaptic antagonists was significantly different than that of neurons derived from adult tissue sources. These results are especially significant because most studies reported with embryonic hippocampal neurons do not begin at two to four weeks in culture. In addition, the utilization of MEAs in lieu of patch-clamp electrophysiology avoided a large-scale, labor-intensive study. These results establish the utility of this unique hybrid system derived from adult hippocampal tissue in combination with MEAs and offer a more appropriate representation of in vivo function for drug discovery. It has application for neuronal development and regeneration as well as for investigations into neurodegenerative disease, traumatic brain injury, and stroke.
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http://dx.doi.org/10.1021/acsbiomaterials.7b00596DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5728088PMC
December 2017

Multiorgan Microphysiological Systems for Drug Development: Strategies, Advances, and Challenges.

Adv Healthc Mater 2018 01 4;7(2). Epub 2017 Dec 4.

Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, 14853, USA.

Traditional cell culture and animal models utilized for preclinical drug screening have led to high attrition rates of drug candidates in clinical trials due to their low predictive power for human response. Alternative models using human cells to build in vitro biomimetics of the human body with physiologically relevant organ-organ interactions hold great potential to act as "human surrogates" and provide more accurate prediction of drug effects in humans. This review is a comprehensive investigation into the development of tissue-engineered human cell-based microscale multiorgan models, or multiorgan microphysiological systems for drug testing. The evolution from traditional models to macro- and microscale multiorgan systems is discussed in regards to the rationale for recent global efforts in multiorgan microphysiological systems. Current advances in integrating cell culture and on-chip analytical technologies, as well as proof-of-concept applications for these multiorgan microsystems are discussed. Major challenges for the field, such as reproducibility and physiological relevance, are discussed with comparisons of the strengths and weaknesses of various systems to solve these challenges. Conclusions focus on the current development stage of multiorgan microphysiological systems and new trends in the field.
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http://dx.doi.org/10.1002/adhm.201701000DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5805562PMC
January 2018

Self-contained, low-cost Body-on-a-Chip systems for drug development.

Exp Biol Med (Maywood) 2017 11 17;242(17):1701-1713. Epub 2017 Feb 17.

1 Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA.

Integrated multi-organ microphysiological systems are an evolving tool for preclinical evaluation of the potential toxicity and efficacy of drug candidates. Such systems, also known as Body-on-a-Chip devices, have a great potential to increase the successful conversion of drug candidates entering clinical trials into approved drugs. Systems, to be attractive for commercial adoption, need to be inexpensive, easy to operate, and give reproducible results. Further, the ability to measure functional responses, such as electrical activity, force generation, and barrier integrity of organ surrogates, enhances the ability to monitor response to drugs. The ability to operate a system for significant periods of time (up to 28 d) will provide potential to estimate chronic as well as acute responses of the human body. Here we review progress towards a self-contained low-cost microphysiological system with functional measurements of physiological responses. Impact statement Multi-organ microphysiological systems are promising devices to improve the drug development process. The development of a pumpless system represents the ability to build multi-organ systems that are of low cost, high reliability, and self-contained. These features, coupled with the ability to measure electrical and mechanical response in addition to chemical or metabolic changes, provides an attractive system for incorporation into the drug development process. This will be the most complete review of the pumpless platform with recirculation yet written.
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http://dx.doi.org/10.1177/1535370217694101DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5786364PMC
November 2017

Fetal Bovine Serum (FBS): Past - Present - Future.

ALTEX 2018 9;35(1):99-118. Epub 2017 Aug 9.

Division of Physiology, Medical University Innsbruck, Innsbruck, Austria.

The supplementation of culture medium with fetal bovine serum (FBS, also referred to as "fetal calf serum") is still common practice in cell culture applications. Due to a number of disadvantages in terms of quality and reproducibility of in vitro data, animal welfare concerns, and in light of recent cases of fraudulent marketing, the search for alternatives and the development of serum-free medium formulations has gained global attention. Here, we report on the 3rd Workshop on FBS, Serum Alternatives and Serum-free Media, where regulatory aspects, the serum dilemma, alternatives to FBS, case-studies of serum-free in vitro applications, and the establishment of serum-free databases were discussed. The whole process of obtaining blood from a living calf fetus to using the FBS produced from it for scientific purposes is de facto not yet legally regulated despite the existing EU-Directive 2010/63/EU on the use of animals for scientific purposes. Together with the above-mentioned challenges, several strategies have been developed to reduce or replace FBS in cell culture media in terms of the 3Rs (Refinement, Reduction, Replacement). Most recently, releasates of activated human donor thrombocytes (human platelet lysates) have been shown to be one of the most promising serum alternatives when chemically-defined media are not yet an option. Additionally, new developments in cell-based assay techniques, advanced organ-on-chip and microphysiological systems are covered in this report. Chemically-defined serum-free media are shown to be the ultimate goal for the majority of culture systems, and examples are discussed.
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http://dx.doi.org/10.14573/altex.1705101DOI Listing
August 2018