Abstract
Following the completion of our first year with the new name SLAS Technology, I am pleased to present the 2018 SLAS Technology Ten. In the past 12 months, SLAS Technology continued to present advances that contribute to a wide range of applications in life sciences research, biomedical innovations, drug development, and clinical and field diagnostics. Key to these advances continues to be miniaturization of technology as well as advances in digital technology that are changing the way imaging is performed and measured. As a result, diagnostic devices, drug development screening technology, and clinical diagnostics have become faster, easier, more robust, and more personalized. This is particularly evidenced by the work presented in our 2017 special issues, “Micro- and Nanotechno-logies for Quantitative Biology and Medicine” and “Personalized and Precision Medicine.”
The SLAS Technology Ten represent some of the most innovative scientific achievements that were featured in SLAS Technology in the past 12 months. This includes micro-, nano-, and digital technologies that are improving drug delivery and therapy against a wide range of diseases, from wound healing to cancer. Advances in microfluidic technologies are both improving clinical diagnostics and allowing for improved diagnostics in the field. Beyond diagnostics, microtechnology advances also are contributing to improved life sciences assays as well as biomedical assays, such as heart-on-a-chip, that are changing the way drugs are developed and evaluated to improve both efficacy and safety. Technology that is contributing to regenerative medicine is also featured in this year’s SLAS Technology Ten.
As editor-in-chief, I thank the 83 authors who contributed to the 2018 SLAS Technology Ten for their hard work, ingenuity, and willingness to stretch the boundaries of what is possible in life sciences and biomedical technology. I also thank the hundreds of other authors who also contributed great work to SLAS Technology in 2017 and the hundreds of manuscript reviewers who worked hard to maintain publication standards. The members of the SLAS Technology Editorial Board and I look forward to presenting more great work in the coming year.
A Wound-Healing Assay Based on Ultraviolet Light Ablation
By Shang-Ying Wu, Yung-Shin Sun, Kuan-Chen Cheng, Kai-Yin Lo
Collective cell migration plays important roles in many physiological processes such as embryonic development, tissue repair, and angiogenesis. A “wound” occurs when epithelial cells are lost and/or damaged due to some external factors, and collective cell migration takes place in the following wound-healing process. To study this cellular behavior, various kinds of wound-healing assays are developed. In these assays, a “wound,” or a “cell-free region,” is created in a cell monolayer mechanically, chemically, optically, or electrically. These assays are useful tools in studying the effects of certain physical or chemical stimuli on the wound-healing process. Most of these methods have disadvantages such as creating wounds of different sizes or shapes, yielding batch-to-batch variation, and damaging the coating of the cell culture surface. In this study, we used ultraviolet (UV) lights to selectively kill cells and create a wound out of a cell monolayer. A comparison between the current assay and the traditional scratch assay was made, indicating that these two methods resulted in similar wound-healing rates. The advantages of this UV-created wound-healing assay include fast and easy procedure, high throughput, and no direct contact with cells.
Engineering A11 Minibody-Conjugated, Polypeptide-Based Gold Nanoshells for Prostate Stem Cell Antigen (PSCA)–Targeted Photothermal Therapy
By Kristine M. Mayle, Kathryn R. Dern, Vincent K. Wong, Kevin Y. Chen, Shijun Sung, Ke Ding, April R. Rodriguez, Scott Knowles, Zachary Taylor, Z. Hong Zhou, Warren S. Grundfest, Anna M. Wu, Timothy J. Deming, Daniel T. Kamei
Currently, there is no curative treatment for advanced metastatic prostate cancer, and options, such as chemotherapy, are often nonspecific, harming healthy cells and resulting in severe side effects. Attaching targeting ligands to agents used in anticancer therapies has been shown to improve efficacy and reduce nonspecific toxicity. Furthermore, the use of triggered therapies can enable spatial and temporal control over the treatment. Here, we combined an engineered prostate cancer–specific targeting ligand, the A11 minibody, with a novel photothermal therapy agent, polypeptide-based gold nanoshells, which generate heat in response to near-infrared light. We show that the A11 minibody strongly binds to the prostate stem cell antigen that is overexpressed on the surface of metastatic prostate cancer cells. Compared to nonconjugated gold nanoshells, our A11 minibody-conjugated gold nanoshell exhibited significant laser-induced, localized killing of prostate cancer cells in vitro. In addition, we improved on a comprehensive heat transfer mathematical model that was previously developed by our laboratory. By relaxing some of the assumptions of our earlier model, we were able to generate more accurate predictions for this particular study. Our experimental and theoretical results demonstrate the potential of our novel minibody-conjugated gold nanoshells for metastatic prostate cancer therapy.
A Smartphone-Based Genotyping Method for Hepatitis B Virus at Point-of-Care Settings
By Huiqin Jiang, Di Wu, Liuwei Song, Quan Yuan, Shengxiang Ge, Xiaoping Min, Ningshao Xia, Shizhi Qian, Xianbo Qiu
We reported a rapid, convenient, and easy-to-use genotyping method for hepatitis B virus (HBV) based on the smartphone at point-of-care (POC) settings. To perform HBV genotyping, especially for genotypes A, B, C, and D, a smartphone is used to image and analyze a one-step immunoassay lateral flow strip functionalized with genotype-specific monoclonal antibodies (mAbs) on multiple capture lines. A light-emitting diode positioned on the top of the lateral flow strip is used to shine the multiple capture lines for excitation. Fluorescence detection is obtained with a smartphone whose camera is used to take the fluorescent images. An intelligent algorithm is developed to first identify each capture line from the fluorescent image and then determine the HBV genotype based on a genotyping model. Based on the pattern of the detection signal from different samples, a custom HBV genotyping model is developed. Custom application software running on a smartphone is developed with Java to collect and analyze the fluorescent image, display the genotyping result, and transmit it if necessary. Compared with the existing methods with nucleic acid analysis, more convenient, instant, and efficient HBV genotyping with significantly lower cost and a simpler procedure can be obtained with the developed smartphone POC HBV genotyping method.
Optimizing Combination Therapy for Acute Lymphoblastic Leukemia Using a Phenotypic Personalized Medicine Digital Health Platform: Retrospective Optimization Individualizes Patient Regimens to Maximize Efficacy and Safety
By Dong-Keun Lee, Vivian Y. Chang, Theodore Kee, Chih-Ming Ho, Dean Ho
Acute lymphoblastic leukemia (ALL) is a blood cancer that is characterized by the overproduction of lymphoblasts in the bone marrow. Treatment for pediatric ALL typically uses combination chemotherapy in phases, including a prolonged maintenance phase with oral methotrexate and 6-mercaptopurine, which often requires dose adjustment to balance side effects and efficacy. A major challenge confronting combination therapy for virtually every disease indication, however, is the inability to pinpoint drug doses that are optimized for each patient, and be able to adaptively and continuously optimize these doses to address comorbidities and other patient-specific physiological changes. To address this challenge, we developed a powerful digital health technology platform based on phenotypic personalized medicine (PPM). PPM identifies patient-specific maps that parabolically correlate drug inputs with phenotypic outputs. In a disease mechanism–independent fashion, we individualized drug ratios and dosages for two pediatric patients with standard-risk ALL in this study via PPM-mediated retrospective optimization. PPM optimization demonstrated that dynamically adjusted dosing of combination chemotherapy could enhance treatment outcomes while also substantially reducing the amount of chemotherapy administered. This may lead to more effective maintenance therapy, with the potential for shortening duration and reducing the risk of serious side effects.
Layer-by-Layer 3D Constructs of Fibroblasts in Hydrogel for Examining Transdermal Penetration Capability of Nanoparticles
By Xiaochun Hou, Shiying Liu, Min Wang, Christian Wiraja, Wei Huang, Peggy Chan, Timothy Tan, Chenjie Xu
Nanoparticles are emerging transdermal delivery systems. Their size and surface properties determine their efficacy and efficiency to penetrate through the skin layers. This work uses three-dimensional (3D) bioprinting technology to generate a simplified artificial skin model to rapidly screen nanoparticles for their transdermal penetration ability. Specifically, this model is built through layer-by-layer alternate printing of blank collagen hydrogel and fibroblasts. Through controlling valve on-time, the spacing between printing lines could be accurately tuned, which could enable modulation of cell infiltration in the future. To confirm the effectiveness of this platform, a 3D construct with one layer of fibroblasts sandwiched between two layers of collagen hydrogel is used to screen silica nanoparticles with different surface charges for their penetration ability, with positively charged nanoparticles demonstrating deeper penetration, consistent with the observation from an existing study involving living skin tissue.
Microfluidic Tissue Mesodissection in Molecular Cancer Diagnostics
By Christine Surrette, David Shoudy, Alex Corwin, Wei Gao, Maria I. Zavodszky, Stanislav L. Karsten, Todd Miller, Michael J. Gerdes, Nichole Wood, John R. Nelson, Chris M. Puleo
We present a mesodissection platform that retains the advantages of laser-based dissection instrumentation with the speed and ease of manual dissection. Tissue dissection in clinical laboratories is often performed by manually scraping a physician-selected region from standard glass slide mounts. In this manner, costs associated with dissection remain low, but spatial resolution is compromised. In contrast, laser microdissection methods maintain spatial resolution that matches the requirements for analysis of important tissue heterogeneity, but remain costly and labor intensive. We demonstrate a microfluidic tool for rapid extraction of histological regions of interest from formalin-fixed paraffin-embedded tissue; it uses a simple and automated method that is compatible with most downstream enzymatic reactions, including protocols used for next-generation DNA sequencing.
Heart-on-a-Chip: An Investigation of the Influence of Static and Perfusion Conditions on Cardiac (H9C2) Cell Proliferation, Morphology, and Alignment
By Anna Kobuszewska, Ewelina Tomecka, Kamil Zukowski, Elzbieta Jastrzebska, Michal Chudy, Artur Dybko, Philippe Renaud, Zbigniew Brzozka
Lab-on-a-chip systems are increasingly used as tools for cultures and investigation of cardiac cells. In this article, we present how the geometry of microsystems and microenvironmental conditions (static and perfusion) influence the proliferation, morphology, and alignment of cardiac cells (rat cardiomyoblasts—H9C2). In addition, studies of cell growth after incubation with verapamil hydrochloride were performed. For this purpose, poly(dimethylsiloxane) (PDMS)–glass microfluidic systems with three different geometries of microchambers (a circular chamber, a longitudinal channel, and three parallel microchannels separated by two rows of micropillars) were prepared. It was found that static conditions did not enhance the growth of H9C2 cells in the microsystems. On the contrary, perfusion conditions had an influence on division, morphology, and the arrangement of the cells. The highest number of cells, their parallel orientation, and their elongated morphology were obtained in the longitudinal microchannel. It showed that this kind of microsystem can be used to understand processes in heart tissue in detail and to test newly developed compounds applied in the treatment of cardiac diseases.
Rapid Prototyping of a Cyclic Olefin Copolymer Microfluidic Device for Automated Oocyte Culturing
By Miguel Berenguel-Alonso, Maria Sabés-Alsina, Roser Morató, Oriol Ymbern, Laura Rodríguez-Vázquez, Oriol Talló-Parra, Julián Alonso-Chamarro, Mar Puyol, Manel López-Béjar
Assisted reproductive technology (ART) can benefit from the features of microfluidic technologies, such as the automation of time-consuming labor-intensive procedures, the possibility to mimic in vivo environments, and the miniaturization of the required equipment. To date, most of the proposed approaches are based on polydimethylsiloxane (PDMS) as platform substrate material due to its widespread use in academia, despite certain disadvantages, such as the elevated cost of mass production. Herein, we present a rapid fabrication process for a cyclic olefin copolymer (COC) monolithic microfluidic device combining hot embossing—using a low-temperature cofired ceramic (LTCC) master—and micromilling. The microfluidic device was suitable for trapping and maturation of bovine oocytes, which were further studied to determine their ability to be fertilized. Furthermore, another COC microfluidic device was fabricated to store sperm and assess its quality parameters throughout time. The study herein presented demonstrates a good biocompatibility of the COC when working with gametes, and it exhibits certain advantages, such as the nonabsorption of small molecules, gas impermeability, and low fabrication costs, all at the prototyping and mass production scale, thus taking a step further toward fully automated microfluidic devices in ART.
An Electrochemical Biosensor for Rapid Detection of Pediatric Bloodstream Infections
By Eranda M. K. Kurundu Hewage, Debbie Spear, Todd M. Umstead, Sanmei Hu, Ming Wang, Pak Kin Wong, Zissis C. Chroneos, E. Scott Halstead, Neal Thomas
Bloodstream infections are major contributing factors of morbidity and mortality among children. Precise and timely identification of causative agents can improve the clinical management and outcome of the infection, potentially saving lives. Electrochemical biosensors previously described by Gao et al. (2017) have the potential to deliver greater speed and discrimination. To date, however, there are no data that determine whether the age of the host would cause bacteria to demonstrate different growth characteristics, or whether pediatric samples would behave differently using this electrochemical biosensor. The importance of this knowledge gap is clear: the preclinical testing phase of this line of research is limited by the relative lack of pediatric healthy blood volunteers to complete this work. Therefore, in this study, we have applied this novel technology to diagnose bacteria spiked into pediatric blood and compared directly with adult blood samples. Only 180 µL of blood was used from both adult and pediatric volunteers and inoculated with Escherichia coli 67, and the signals generated at different time points were compared. We were able to demonstrate that the signals generated by adult and pediatric blood were not significantly different with this detection technology.
Adaptation of a Simple Microfluidic Platform for High-Dimensional Quantitative Morphological Analysis of Human Mesenchymal Stromal Cells on Polystyrene-Based Substrates
By Johnny Lam, Ross A. Marklein, Jose A. Jimenez-Torres, David J. Beebe, Steven R. Bauer, Kyung E. Sung
Multipotent stromal cells (MSCs; often called mesenchymal stem cells) have garnered significant attention within the field of regenerative medicine because of their purported ability to differentiate down musculoskeletal lineages. Given the inherent heterogeneity of MSC populations, recent studies have suggested that cell morphology may be indicative of MSC differentiation potential. Toward improving current methods and developing simple yet effective approaches for the morphological evaluation of MSCs, we combined passive pumping microfluidic technology with high-dimensional morphological characterization to produce robust tools for standardized high-throughput analysis. Using ultraviolet (UV) light as a modality for reproducible polystyrene substrate modification, we show that MSCs seeded on microfluidic straight-channel devices incorporating UV-exposed substrates exhibited morphological changes that responded accordingly to the degree of substrate modification. Substrate modification also effected greater morphological changes in MSCs seeded at a lower rather than higher density within microfluidic channels. Despite largely comparable trends in morphology, MSCs seeded in microscale as opposed to traditional macroscale platforms displayed much higher sensitivity to changes in substrate properties. In summary, we adapted and qualified microfluidic cell culture platforms comprising simple straight-channel arrays as a viable and robust tool for high-throughput quantitative morphological analysis to study cell–material interactions.