A PET-compatible tissue bioreactor for research, discovery, and validation of imaging biomarkers and radiopharmaceuticals: system design and proof-of-concept studies

The 'bIUreactor': An Open-Source 3D Tissue Research Platform

We developed the open-source bIUreactor research platform for studying 3D structured tissues. The versatile and modular platform allows a researcher to generate 3D tissues, culture them with oxygenated perfusion, and provide cyclic loading, all in their own lab (in laboratorium) for an all in cost of $8,000 including 3D printer, printing resin, and electronics. We achieved this by applying a design philosophy that leverages 3D printing, open-source software and hardware, and practical techniques to produce the following: 1. perfusible 3D tissues, 2. a bioreactor chamber for tissue culture, 3. a module for applying cyclic compression, 4. a peristaltic pump for providing oxygenated perfusion to 3D tissues, 5. motor control units, and 6. open-source code for running the control units. By making it widely available for researchers to investigate 3D tissue models and easy for them to use, we intend for the bIUreactor to democratize 3D tissue research, therefore increasing the pace and scale of biomedical research discoveries using 3D tissue models.

Investigating the effects of Ceylon cinnamon water extract on HepG2 cells for Type 2 diabetes therapy

Cinnamon and its extracts have been used as herbal remedies for many ailments, including for reducing insulin resistance and diabetes complications. Type 2 diabetes mellitus (T2DM) is a rapidly growing health concern around the world. Although many drugs are available for T2DM treatment, side effects and costs can be considerable, and there is increasing interest in natural products for managing chronic health conditions. Cinnamon may decrease the expression of genes associated with T2DM risk. The purpose of this study was to evaluate the effects of cinnamon water extract (CWE) compared with metformin on T2DM-related gene expression. HepG2 human hepatoma cells, widely used in drug metabolism and hepatotoxicity studies, were treated with different concentrations of metformin or CWE for 24 or 48 h. Cell viability was assessed by MTT (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay and glucose uptake was compared in untreated and CWE- or metformin-treated cells under high-glucose conditions. Finally, total RNA was extracted and analyzed by RNA sequencing (RNA-seq), and bioinformatics analyses were performed to compare the transcriptional effects of CWE and metformin. We found cell viability was better in cells treated with CWE than in metformin-treated cells, demonstrating that CWE was not toxic at tested doses. CWE significantly increased glucose uptake in HepG2 cells, to the same degree as metformin (1.4-fold). RNA-seq data revealed CWE and metformin both induced significantly increased (1.3- to 1.4-fold) glucose uptake gene expression compared with untreated controls. Transcriptional differences between CWE and metformin were not significant. The effects of 0.125 mg mL^-1 CWE on gene expression were comparable to 1.5 mg mL^-1 (9.5 mM) metformin. In addition, gene expression at 0.125 mg mL^-1 CWE was comparable to 1.5 mg mL^-1 (9.5 mM) metformin. Our results reveal that CWE's effects on cell viability, glucose uptake, and gene expression in HepG2 cells are comparable to those of metformin, suggesting CWE may be an effective dietary supplement for mitigating T2DM-related metabolic dysfunction.

Bioreactor design and validation for manufacturing strategies in tissue engineering

The fields of regenerative medicine and tissue engineering offer new therapeutic options to restore, maintain or improve tissue function following disease or injury. To maximize the biological function of a tissue-engineered clinical product, specific conditions must be maintained within a bioreactor to allow the maturation of the product in preparation for implantation. Specifically, the bioreactor should be designed to mimic the mechanical, electrochemical and biochemical environment that the product will be exposed to in vivo. Real-time monitoring of the functional capacity of tissue-engineered products during manufacturing is a critical component of the quality management process. The present review provides a brief overview of bioreactor engineering considerations. In addition, strategies for bioreactor automation, in-line product monitoring and quality assurance are discussed.

A vertical-flow bioreactor array compacts hepatocytes for enhanced polarity and functions

Although hepatocytes in vivo experience intra-abdominal pressure (IAP), pressure is typically not incorporated in hepatocyte culture systems. The cuboidal cell shape and extent of intercellular contact between cultured hepatocytes are critical parameters that influence the differentiated hepatic phenotype. Using a microfluidic device, the application of pressure to artificially compact cells and forge cell-cell interactions was previously demonstrated to be effective in accelerating hepatic repolarization. In seeking to implement this approach to higher throughput culture platforms for potential drug screening applications, we specifically designed a vertical-flow compaction bioreactor array (VCBA) that compacts hepatocytes within the range of IAP and portal pressure in vivo in a multi-well setup. As a result of vertical perfusion-generated forces, hepatocytes not only exhibited accelerated repolarization, an in vivo-like cuboidal morphology, but also better maintained hepatic functions in long-term culture as compared to the same cells cultured under static conditions. As a novel engineering tool to modulate cell compaction and intercellular interactions, this platform is a promising approach to confer tight control over hepatocyte repolarization for in vitro culture.