Effect of Various Toothpaste Tablets on Gloss and Surface Roughness of Resin-based Composite Materials

OBJECTIVES

To evaluate the effect of various toothpaste tablets on gloss and surface roughness of resin-based composite.

METHODS AND MATERIALS

Sixty-four resin-based composite specimens were divided into four groups of 16 specimens each. Gloss and roughness were measured before and after simulated brushing with three types of toothpaste tablets and one conventional toothpaste: CT: Chewtab Toothpaste Tablets; AT: Anticavity Toothpaste Tablets; HC: Charcoal Toothpaste Tablets; CP: Cavity Protection toothpaste. The Kruskal- Wallis procedure was performed to compare the differences by groups. Post-hoc comparisons were conducted with Bonferroni corrections (α=0.05).

RESULTS

There was a significant drop in gloss for all groups. CT and AT maintained the highest gloss with means of 81.6 GU and 74.1 GU, respectively. The lowest gloss of 24.5 GU was observed for HC. There was a significant increase in roughness for all groups except for CT. CT had the lowest roughness with a mean of 0.034 μm, while HC had the highest roughness with a mean of 0.074 μm. There was a significant correlation between post-brushing gloss and post-brushing roughness (p<0.001, r=-0.884).

CONCLUSION

Chewtab Toothpaste Tablets had the least effect on gloss and roughness, while Charcoal Toothpaste Tablets had the most negative effect on the surface properties of resin-based composites.

Vascularized tissue on mesh-assisted platform (VT-MAP): a novel approach for diverse organoid size culture and tailored cancer drug response analysis

This study presents the vascularized tissue on mesh-assisted platform (VT-MAP), a novel microfluidic in vitro model that uses an open microfluidic principle for cultivating vascularized organoids. Addressing the gap in 3D high-throughput platforms for drug response analysis, the VT-MAP can host tumor clusters of various sizes, allowing for precise, size-dependent drug interaction assessments. Key features include capability for forming versatile co-culture conditions (EC, fibroblasts and colon cancer organoids) that enhance tumor organoid viability and a perfusable vessel network that ensures efficient drug delivery and maintenance of organoid health. The VT-MAP enables the culture and analysis of organoids across a diverse size spectrum, from tens of microns to several millimeters. The VT-MAP addresses the inconsistencies in traditional organoid testing related to organoid size, which significantly impacts drug response and viability. Its ability to handle various organoid sizes leads to results that more accurately reflect patient-derived xenograft (PDX) models and differ markedly from traditional in vitro well plate-based methods. We introduce a novel image analysis algorithm that allows for quantitative analysis of organoid size-dependent drug responses, marking a significant step forward in replicating PDX models. The PDX sample from a positive responder exhibited a significant reduction in cell viability across all organoid sizes when exposed to chemotherapeutic agents (5-FU, oxaliplatin, and irinotecan), as expected for cytotoxic drugs. In sharp contrast, PDX samples of a negative responder showed little to no change in viability in smaller clusters and only a slight reduction in larger clusters. This differential response, accurately replicated in the VT-MAP, underscores its ability to generate data that align with PDX models and in vivo findings. Its capacity to handle various organoid sizes leads to results that more accurately reflect PDX models and differ markedly from traditional in vitro methods. The platform's distinct advantage lies in demonstrating how organoid size can critically influence drug response, revealing insights into cancer biology previously unattainable with conventional techniques.

Patient-derived tumor spheroid-induced angiogenesis preclinical platform for exploring therapeutic vulnerabilities in cancer

This study addresses the demand for research models that can support patient-treatment decisions and clarify the complexities of a tumor microenvironment by developing an advanced non-animal preclinical cancer model. Based on patient-derived tumor spheroids (PDTS), the proposed model reconstructs the tumor microenvironment with emphasis on tumor spheroid-driven angiogenesis. The resulting microfluidic chip system mirrors angiogenic responses elicited by PDTS, recapitulating patient-specific tumor conditions and providing robust, easily quantifiable outcomes. Vascularized PDTS exhibited marked angiogenesis and tumor proliferation on the microfluidic chip. Furthermore, a drug that targets the vascular endothelial growth factor receptor 2 (VEGFR2, ramucirumab) was deployed, which effectively inhibited angiogenesis and impeded tumor invasion. This innovative preclinical model was used for investigating distinct responses for various drug combinations, encompassing HER2 inhibitors and angiogenesis inhibitors, within the context of PDTS. This integrated platform could potentially advance precision medicine by harmonizing diverse data points within the tumor microenvironment with a focus on the interplay between cancer and the vascular system.

Revealing the clinical potential of high-resolution organoids

The symbiotic interplay of organoid technology and advanced imaging strategies yields innovative breakthroughs in research and clinical applications. Organoids, intricate three-dimensional cell cultures derived from pluripotent or adult stem/progenitor cells, have emerged as potent tools for in vitro modeling, reflecting in vivo organs and advancing our grasp of tissue physiology and disease. Concurrently, advanced imaging technologies such as confocal, light-sheet, and two-photon microscopy ignite fresh explorations, uncovering rich organoid information. Combined with advanced imaging technologies and the power of artificial intelligence, organoids provide new insights that bridge experimental models and real-world clinical scenarios. This review explores exemplary research that embodies this technological synergy and how organoids reshape personalized medicine and therapeutics.

Understanding organotropism in cancer metastasis using microphysiological systems

Cancer metastasis, the leading cause of cancer-related deaths, remains a complex challenge in medical science. Stephen Paget's "seed and soil theory" introduced the concept of organotropism, suggesting that metastatic success depends on specific organ microenvironments. Understanding organotropism not only offers potential for curbing metastasis but also novel treatment strategies. Microphysiological systems (MPS), especially organ-on-a-chip models, have emerged as transformative tools in this quest. These systems, blending microfluidics, biology, and engineering, grant precise control over cell interactions within organ-specific microenvironments. MPS enable real-time monitoring, morphological analysis, and protein quantification, enhancing our comprehension of cancer dynamics, including tumor migration, vascularization, and pre-metastatic niches. In this review, we explore innovative applications of MPS in investigating cancer metastasis, particularly focusing on organotropism. This interdisciplinary approach converges the field of science, engineering, and medicine, thereby illuminating a path toward groundbreaking discoveries in cancer research.

Patient-Derived Microphysiological Systems for Precision Medicine

Patient-derived microphysiological systems (P-MPS) have emerged as powerful tools in precision medicine that provide valuable insight into individual patient characteristics. This review discusses the development of P-MPS as an integration of patient-derived samples, including patient-derived cells, organoids, and induced pluripotent stem cells, into well-defined MPSs. Emphasizing the necessity of P-MPS development, its significance as a nonclinical assessment approach that bridges the gap between traditional in vitro models and clinical outcomes is highlighted. Additionally, guidance is provided for engineering approaches to develop microfluidic devices and high-content analysis for P-MPSs, enabling high biological relevance and high-throughput experimentation. The practical implications of the P-MPS are further examined by exploring the clinically relevant outcomes obtained from various types of patient-derived samples. The construction and analysis of these diverse samples within the P-MPS have resulted in physiologically relevant data, paving the way for the development of personalized treatment strategies. This study describes the significance of the P-MPS in precision medicine, as well as its unique capacity to offer valuable insights into individual patient characteristics.

Angio-Net: deep learning-based label-free detection and morphometric analysis of in vitro angiogenesis

Despite significant advancements in three-dimensional (3D) cell culture technology and the acquisition of extensive data, there is an ongoing need for more effective and dependable data analysis methods. These concerns arise from the continued reliance on manual quantification techniques. In this study, we introduce a microphysiological system (MPS) that seamlessly integrates 3D cell culture to acquire large-scale imaging data and employs deep learning-based virtual staining for quantitative angiogenesis analysis. We utilize a standardized microfluidic device to obtain comprehensive angiogenesis data. Introducing Angio-Net, a novel solution that replaces conventional immunocytochemistry, we convert brightfield images into label-free virtual fluorescence images through the fusion of SegNet and cGAN. Moreover, we develop a tool capable of extracting morphological blood vessel features and automating their measurement, facilitating precise quantitative analysis. This integrated system proves to be invaluable for evaluating drug efficacy, including the assessment of anticancer drugs on targets such as the tumor microenvironment. Additionally, its unique ability to enable live cell imaging without the need for cell fixation promises to broaden the horizons of pharmaceutical and biological research. Our study pioneers a powerful approach to high-throughput angiogenesis analysis, marking a significant advancement in MPS.

Patient-derived exosomes facilitate therapeutic targeting of oncogenic MET in advanced gastric cancer

Gastric cancer (GC) with peritoneal metastases and malignant ascites continues to have poor prognosis. Exosomes mediate intercellular communication during cancer progression and promote therapeutic resistance. Here, we report the significance of exosomes derived from malignant ascites (EXOAscites) in cancer progression and use modified exosomes as resources for cancer therapy. EXOAscites from patients with GC stimulated invasiveness and angiogenesis in an ex vivo three-dimensional autologous tumor spheroid microfluidic system. EXOAscites concentration increased invasiveness, and blockade of their secretion suppressed tumor progression. In MET-amplified GC, EXOAscites contain abundant MET; their selective delivery to tumor cells enhanced angiogenesis and invasiveness. Exosomal MET depletion substantially reduced invasiveness; an additive therapeutic effect was induced when combined with MET and/or VEGFR2 inhibition in a patient-derived MET-amplified GC model. Allogeneic MET-harboring exosome delivery induced invasion and angiogenesis in a MET non-amplified GC model. MET-amplified patient tissues showed higher exosome concentration than their adjacent normal tissues. Manipulating exosome content and production may be a promising complementary strategy against GC.

Passivation effect on Cd0.95Mn0.05Te0.98Se0.02 radiation detection performance

CdTe-based detectors have the problem of Te-rich surface layers caused by Br etching, which is one of fabrication steps. Te-rich layer acts as a trapping center and serves as an additional source of charge carriers, thereby degrading transport property of charge carriers and enriching leakage current on surface of detector. To solve this problem, we introduced sodium hypochlorite (NaOCl) as a passivant, and investigated its effect on Cd0.95Mn0.05Te0.98Se0.02 (CMTS), by analyzing chemical state of surface and its performance. After passivation with NaOCl, the results of X-ray photoelectron spectroscopy (XPS) shows the formation of tellurium oxide and elimination of water on CMTS surface, and CMTS presented enhanced performance with Am-241 radioisotope. Consequently, it is demonstrated that the passivation with NaOCl reduces leakage current, compensates defect, and elevates transport of charge carriers, thereby decreasing charge loss of carriers and improving performance of CMTS detector.

Clinical Implication of HER2 Aberration in Patients With Metastatic Cancer Using Next-Generation Sequencing: A Pan-Tumor Analysis

PURPOSE

Human epidermal growth factor receptor 2 (HER2) protein expression or gene amplification is a significant predictive biomarker for identifying patients with cancer, who may benefit from HER2-targeted therapy. The aim of this study was to survey the proportion of patients who had HER2 aberration and to investigate the correlation between HER2 amplification and HER2 overexpression in immunohistochemistry (IHC) as a real-world data.

METHODS

We surveyed the incidence of HER2 aberration including mutation (single-nucleotide variant [SNV]), amplification (copy-number variation), and fusion by next-generation sequencing (NGS) in 2,119 patients with cancer from Samsung Medical Center in South Korea.

RESULTS

Of 2,119 patients with cancer, 189 patients (8.9%) had HER2 aberration in their tumor specimen. Of 189 patients, 113 (5.3%) patients had HER2 amplification, 82 (3.9%) patients had HER2 mutations, and 11 (0.5%) patients had HER2 fusion. Of note, 10 patients (0.5%) had concurrent HER2 amplification and HER2 fusion. In addition, we identified that HER2 protein overexpression was strongly related to HER2 amplification by NGS. Of 74 patients with HER2 amplification only by NGS test, 64 patients (86.5%) had HER2 overexpression by IHC. Of 10 patients with concurrent HER2 amplification and fusion, 80% patients were HER2 overexpression. Among 51 patients with only HER2 mutation (SNV), 9 patients (17.6%) were HER2 (+). Interestingly, almost all patients with colorectal cancer (11 of 12) with HER2 amplification had very strong HER2 overexpression (3+) in their tumor specimen.

CONCLUSION

In conclusion, we showed that when patients with metastatic cancer receive NGS test, approximately 8.9% have HER2 aberrations in their tumor specimen. Most patients have HER2 amplification, and a small percentage of patients have HER2 fusion. A great majority of patients with HER2 amplification and/or HER2 fusion had HER2 (+) tumor by IHC.

MET gene alterations predict poor survival following chemotherapy in patients with advanced cancer

Background: To aid in oncology drug development, we investigated MET proto-oncogene receptor tyrosine kinase gene aberrations in 2,239 oncology patients who underwent next-generation sequencing (NGS) in clinical practice. Materials and methods: From November 2019 to January 2021, 2,239 patientswith advanced solid tumors who visited oncology clinics underwent NGS. The NGS panel included >500 comprehensive NGS tests using archival tissue specimens. Programmed death-ligand 1(PD-L1) 22C3 assay results and clinical records regarding initial chemotherapy were available for 1,137 (50.8%) and 1,761 (78.7%) patients, respectively for overall survival (OS) analysis. Results: The 2,239 patients represented 37 types of cancer. The NGS panel included >500 genes, microsatellite instability status, tumor mutational burden, and fusions. The most common cancer types were colorectal (N = 702), gastric (N = 481), and sarcoma (N = 180). MET aberrations were detected in 212 patients. All MET-amplified tumors had microsatellite stable status, and 8 had a high tumor mutational burden. Of 46 patients with MET-amplified cancers, 8 had MET-positive protein expression by immunohistochemistry (2+ and 3+). MET fusion was detected in 10 patients. Partner genes of MET fusion included ST7, TFEC, LRRD1, CFTR, CAV1, PCM1, HLA-DRB1, and CAPZA2. In survival analysis, patients with amplification of MET gene fusion had shorter OS and progression-free survival (PFS) than those without. Thus, MET aberration was determined to be a factor of response to chemotherapy. Conclusion: Approximately 2.1% and 0.4% of patients with advanced solid tumors demonstrated MET gene amplification and fusion, respectively, and displayed a worse response to chemotherapy and significantly shorter OS and PFS than those without MET gene amplification or fusion.

All-in-One microfluidic design to integrate vascularized tumor spheroid into high-throughput platform

The development of a scalable and highly reproducible in vitro tumor microenvironment (TME) platform still sheds light on new insights into cancer metastasis mechanisms and anticancer therapeutic strategies. Here, we present an all-in-one injection molded plastic array 3D culture platform (All-in-One-IMPACT) that integrates vascularized tumor spheroids for highly reproducible, high-throughput experimentation. This device allows the formation of self-assembled cell spheroids on a chip by applying the hanging drop method to the cell culture channel. Then, when the hydrogel containing endothelial cells and fibroblasts is injected, the spheroid inside the droplet can be patterned together in three dimensions along the culture channel. In just two steps above, we can build a vascularized TME within a defined area. This process does not require specialized user skill and minimizes error-inducing steps, enabling both reproducibility and high-throughput of the experiment. We have successfully demonstrated the process, from spheroid formation to tumor vascularization, using patient-derived cancer cells (PDCs) as well as various cancer cell lines. Furthermore, we performed combination therapies with Taxol (paclitaxel) and Avastin (bevacizumab), which are used in standard care for metastatic cancer. The All-in-One IMPACT is a powerful tool for establishing various anticancer treatment strategies through the development of a complex TME for use in high-throughput experiments. This article is protected by copyright. All rights reserved.

Engineering Organ-on-a-Chip to Accelerate Translational Research

We guide the use of organ-on-chip technology in tissue engineering applications. Organ-on-chip technology is a form of microengineered cell culture platform that elaborates the in-vivo like organ or tissue microenvironments. The organ-on-chip platform consists of microfluidic channels, cell culture chambers, and stimulus sources that emulate the in-vivo microenvironment. These platforms are typically engraved into an oxygen-permeable transparent material. Fabrication of these materials requires the use of microfabrication strategies, including soft lithography, 3D printing, and injection molding. Here we provide an overview of what is an organ-on-chip platform, where it can be used, what it is composed of, how it can be fabricated, and how it can be operated. In connection with this topic, we also introduce an overview of the recent applications, where different organs are modeled on the microscale using this technology.

Abstract 6352: Ascites derived exosomes promote progression of advanced gastric cancers

Gastric cancer (GC) with peritoneal metastasis accompanied by a sequential buildup of malignant ascites currently has no curative therapy; accordingly, developing novel biomarkers is critical for reducing the severity of this disease. Recently, the significance of exosomes as a biomarker has gradually increased; exosomes act as a critical mediator of cell-cell intracellular communication in cancer progression. In this study, we characterized exosomes derived from ascites (ExoAscites) of four patients with GC; the high concentration of ExoAscites was observed with the morphology of round-cup shape. Our results showed that ExoAscites were actively endocytosed into cancer spheroid with time. The tropism of ExoAscites showed a predominance to GC rather than stromal cells.Furthermore, their importance on cancer invasiveness and angiogenesis are verified in the 3D microfluidic cancer spheroid model. Interestingly, tumor progression was gradually promoted by treatment with increasing ExoAscites concentrations. Collectively, these results support the view that exosomes from ascites fluids act as mediators of the tumor microenvironment, thus providing conditions favorable for future tumor progression.

Citation Format: Sujin Hyung, Jihoon Ko, In-kyung Lee, Noo Li Jeon, Jeeyun Lee. Ascites derived exosomes promote progression of advanced gastric cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6352.

Abstract 3206: Three-dimensional tumor angiogenesis mapping in metastatic gastric cancer patients

Background: Patients with gastric cancer (GC) develop malignant ascites as the disease progresses due to peritoneal metastasis. The presence of malignant ascites is a critical prognostic sign of tumor progression. With an understanding of these patient subsets, better optimized treatment strategies are needed.

Method: We analyzed whole exome and transcriptome sequences of ascites or primary tumor samples obtained from 46 patients with advanced gastric cancer. In addition, we engineered a microfluidic-based gastric cancer patient-on-a-chip (GRASP) to develop a tumor-induced patient-specific angiogenesis model and evaluate the ramucirumab responses.

Results: Through single-cell sequencing, 46 patients were classified into two groups according to the level of KDR gene (VEGFR2) expression. (high KDR, N=25; low KDR, N=21) In the group with high VEGFR2 expression, 68% (17 of 25) samples were from ascites, and all samples with low KDR were from primary tumors. In the GRASP system, the quantitative results of random co-culture of PDCs from 46 patients with blood vessels demonstrated high concordances to the sequence results. In addition, the angiogenesis inhibitory effect of Ramucirumab was also high in the KDR high group.

Conclusion: Understanding angiogenesis inhibition as part of a therapeutic strategy considering tumor microenvironment has important clinical implications. It would be a significant outcome for our analysis system to bring therapeutic benefits to GC patients.

Citation Format: Jihoon Ko, Sujin Hyung, Minae An, Noo Li Jeon, Jeeyun Lee. Three-dimensional tumor angiogenesis mapping in metastatic gastric cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3206.

Prevalence of MET aberration using next generation sequencing in oncology clinic: A real-world experience

e16099

Background: MET has been known as an important therapeutic target in various solid cancer types. With the establishment of next-generation sequencing (NGS) in the oncology clinics, understanding the incidence of MET aberration in patients with metastatic cancer is critical for oncology drug development and efficacy. We investigated MET gene aberration in 2,239 oncology patients who underwent NGS in clinical practice with real-world data. Methods: From Nov. 2019 to Jan. 2021, 2,239 metastatic solid tumor patients who visited oncology clinic were enrolled in the NGS analysis. The NGS panel (TruSight Oncology 500 Assay, Illumina) was over 500 comprehensive sequencing using archival tissue specimen. In addition, PD-L1 22C3 assay results were available in 1,137 patients (50.8%) and 1,761(78.7%) patients had clinical record about 1st chemotherapy for overall survival analysis. Results: 2,239 patients with metastatic solid tumor (37 cancer types) received NGS as part of the clinical practice with an aim to be guided to targeted agents or immunotherapy. The most common cancer types were CRC (N = 702, 31.4%), followed by GC (N = 481, 21.5%), and sarcoma (N = 180, 8.0%). Of 2,239 patients, any MET aberrations (CNVs, fusions, and SNV) were detected in 212 patients. Of the 46 patients with MET amplification, 14 (30.4%) were GC followed by CRC (N = 10, 21.7%), melanoma (N = 7, 15.2%), CCC (N = 6, 13.0%), sarcoma (N = 2, 4.3%), HCC (N = 2, 4.3%), NSCLC (N = 2, 4.3%), pancreatic cancer (N = 2, 4.3%), and gallbladder cancer (N = 1, 2.2%). All MET-amplified tumors had microsatellite stable (MSS) status and 17.4 % patients (N = 8) were TMB-high status. And, 8 of MET-amplified patients concurrently showed MET-positive protein expression by IHC (2+ and 3+). Of note, MET fusion was detected in 0.4% (10 of 2,239) of the patients. The partner gene included ST7, TFEC, LRRD1, CFTR, CAV1, PCM1, HLA-DRB1 and CAPZA2. In survival analysis, patients having MET amplification or fusion had shorter OS and PFS than the others, suggesting MET aberration was an important key factor that could determine final response results to current chemotherapy. Conclusions: Based on our comprehensive NGS survey focused on MET aberration, we identified approximately 2.1% MET amplification and 0.4% MET fusion in patients with metastatic solid tumors. They showed worse response after chemotherapy and shorter OS and PFS.

Comprehensive landscape of tumor angiogenesis via integrating RNA sequencing and three-dimensional microphysiological system

e16058

Background: The prognosis of gastric cancer (GC) patients with peritoneal metastasis with malignant ascites is very poor. We developed an in vitro tumor angiogenesis platform “TumorAngioChip” to reproduce tumor angiogenesis in 45 gastric cancer patients and mapping their angiogenesis characteristics. This platform, which can predict the features of tumor angiogenesis and drug responsiveness in patient’s samples, opens up potential for a variety of combination therapies, including ramucirumab. Methods: We built a PDC library for the study based on samples of 45 GC patients receiving treatment at Samsung Medical Center. For all patient samples, whole exome and transcriptome sequencing was performed for subtype clustering. TumorAngioChip was fabricated by design prototyping through 3D printing and mass production through injection molding. Patient-derived tumor angiogenesis reconstructed on TumorAngioChip was analyzed using an algorithm for morphological image processing of 3D images obtained through confocal microscopy. Results: Of 45 GC patients, we investigated TumorAngioChip analysis and transcriptome sequencing to classify them as KDR-High (N = 24) and KDR-Low (N = 21) ( P = 4.481e-08, Wilcoxon signed-rank test). In the TumorAngioChip–patient mapping analysis, we clearly demonstrated that GC patients with high KDR level regardless to their GC TCGA subtype had high index of tumor-induced angiogenesis and cancer invasiveness measured by TumorAngioChip ( KDR-High vs. KDR-low group; mean sprouting length: 1.455 × 103 vs. 0.946 × 103, respectively, P < 0.0001; vessel density: 3.470 vs. 2.637, respectively, P < 0.0001; sprouts number: 219 vs. 111, respectively, P < 0.0001; vessel total length: 4.931 × 104 vs. 3.919 × 104, respectively, P = 0.0011). Conclusions: This study is the first attempt to elucidate cancer angiogenesis in large-scale GC patients via a microfluidic-based in vitro system. By integrating transcriptome sequencing and TumorAngioChip-based 3D morphological image processing, we demonstrated tumor angiogenesis mapping for GC patients and further revealed the benefits of ramucirumab in individual patients. The application of TumorAngioChip shows its potential as a novel preclinical drug screening platform to identify effective angiogenesis inhibitors reflecting TME for the first time.

Exosome in ascites can be a potential therapeutic target for gastric cancer with malignant ascites

e15008

Background: Recently, exosomes widely distributed in body fluids, including blood, urine, saliva, and ascites, serve as an essential biomarker in cancers. Exosomes are considered as a cargo of potential oncogenic protein such as MET during cancer progression. Methods: Exosomes from the malignant ascites (exoAscites) of four patients with stage IV gastric cancers (GCs) were isolated by different serial centrifugation steps (300 g, 2000 g, 10,000 g, and 110,000 g at 4). After ultracentrifugation, nanoparticle tracking analysis, western blotting, and immunocytochemistry were performed for characterization of the exoAscites. Results: In this study, we enrolled 4 patients with malignant ascites which needed to be drained for symptom control. In all 4 patients, we successfully isolated highly concentrated exosomes in 50 ml of ascites (range, 55108 – 260 108exosomes/ml). (pt#1, 140108 particles/ml; pt#2, 138 108, pt#3, 55.6 108; pt#4, 260 108 exosomes/ml). In twopatients with MET amplification (METamp) in tumor specimens, exoAscites retrieved from the ascites harbored cMET protein in exosomes. In addition, the in-vitro cancer microenvironment model showed that tropism of exoAscitesharboring cMET oncogenic protein had the potential to induce cancer progression (EpCAM immunofluorescent intensity value; a 2.4-fold increase compared to control). In this model, the cancer invasiveness and angiogenesis were significantly enhanced by treatment with exoAscites with over time. (2.4-(EpCAM immunofluorescent intensity) and 3.6-(CD31 immunofluorescent intensity) fold increase, respectively). Furthermore, the cancer invasiveness was substantially increased as the exosome concentration increased from 0, 101, 103, 105, 107 exosome particles/ml. Cancer invasiveness measured by EpCAM immunofluorescent intensity was significantly decreased upon exosiMET treatment in MET amplified GC cells when compared to the control. Conclusions: For the first time, we demonstrated that exosomes from malignant ascites carry MET protein in their exosomes. Exosomes may be early mediators of cancer spread in GC.

Vascularization of iNSC spheroid in a 3D spheroid-on-a-chip platform enhances neural maturation

In vitro platforms for studying the human brain have been developed, and brain organoids derived from stem cells have been studied. However, current organoid models lack three-dimensional (3D) vascular networks, limiting organoid proliferation, differentiation, and apoptosis. In this study, we created a 3D model of vascularized spheroid cells using an injection-molded microfluidic chip. We cocultured spheroids derived from induced neural stem cells (iNSCs) with perfusable blood vessels. Gene expression analysis and immunostaining revealed that the vascular network greatly enhanced spheroid differentiation and reduced apoptosis. This platform can be used to further study the functional and structural interactions between blood vessels and neural spheroids, and ultimately to simulate brain development and disease.

Reducing tumor invasiveness by ramucirumab and TGF-β receptor kinase inhibitor in a diffuse-type gastric cancer patient-derived cell model

BACKGROUND

Diffuse-type gastric cancer (GC) is known to be more aggressive and relatively resistant to conventional chemotherapy. Hence, more optimized treatment strategy is urgently needed in diffuse-type GC.

METHODS

Using a panel of 10 GC cell lines and 3 GC patient-derived cells (PDCs), we identified cell lines with high EMTness which is a distinct feature for diffuse-type GC. We treated GC cells with high EMTness with ramucirumab alone, TGF-β receptor kinase inhibitor (TEW-7197) alone, or in combination to investigate the drug's effects on invasiveness, spheroid formation, EMT marker expression, and tumor-induced angiogenesis using a spheroid-on-a-chip model.

RESULTS

Both TEW-7197 and ramucirumab treatments profoundly decreased invasiveness of EMT-high cell lines and PDCs. With a 3D tumor spheroid-on-a-chip, we identified versatile influence of co-treatment on cancer cell-induced blood vessel formation as well as on EMT progression in tumor spheroids. The 3D tumor spheroid-on-a-chip demonstrated that TEW-7197 + ramucirumab combination significantly decreased PDC-induced vessel formation.

CONCLUSIONS

In this study, we showed TEW-7197 and ramucirumab considerably decreased invasiveness, thus EMTness in a panel of diffuse-type GC cell lines including GC PDCs. Taken together, we confirmed that combination of TEW-7197 and ramucirumab reduced tumor spheroid and GC PDC-induced blood vessel formation concomitantly in the spheroid-on-a-chip model.

Anchor-IMPACT: A standardized microfluidic platform for high-throughput antiangiogenic drug screening

In vitro models are becoming more advanced to truly present physiological systems while enabling high-throughput screening and analysis. Organ-on-a-chip devices provide remarkable results through the reconstruction of a three-dimensional (3D) cellular microenvironment although they need to be further developed in terms of multiple liquid patterning principle, material properties, and scalability. Here we present a 3D anchor-based microfluidic injection-molded plastic array culture platform (Anchor-IMPACT) that enables selective, space-intensive patterning of hydrogels using anchor-island for high-throughput angiogenesis evaluation model. Anchor-IMPACT consists of a central channel and an anchor-island, integrating the array into an abbreviated 96-well plate format with a standard microscope slide size. The anchor-island enables selective 3D cell patterning without channel-to-channel contact or any hydrogel injection port using an anchor structure unlike conventional culture compartment. The hydrogel was patterned into defined regions by spontaneous capillary flow under hydrophilic conditions. We configured multiple cell patterning structures to investigate the angiogenic potency of colorectal cancer cells in Anchor-IMPACT and the morphological properties of the angiogenesis induced by the paracrine effect were evaluated. In addition, the efficacy of anticancer drugs against angiogenic sprouts was verified by following dose-dependent responses. Our results indicate that Anchor-IMPACT offers not only a model of high-throughput experimentation but also an advanced 3D cell culture platform and can significantly improve current in vitro models while providing the basis for developing predictive preclinical models for biopharmaceutical applications.

Fast-ion Dα spectroscopy diagnostic at KSTAR

A fast-ion Dα (FIDA) diagnostics system was installed for core and edge measurements on KSTAR. This system has two tangential FIDA arrays that cover both blue- and redshifted Dα lines (cold: 656.09 nm) in active views along the neutral beam 1 A centerline. The spectral band is 647-662.5 nm, and it covers the Doppler shift of the emission from the maximum energy of the neutral beam (100 keV). A curved filter strip with a motorized stage adequately prevents saturation of the electron multiplying charge-coupled device signal by the cold Dα line from the plasma edge. From comparisons of the measured spectra and FIDASIM modeling code, the FIDA spectra are well matched quantitatively. Moreover, the first measurements show that the FIDA radiance agrees with the neutron rate in the time trace during external heating and perturbation. In addition, responses are observed in the core FIDA radiance during the edge-localized mode cycle.

Monolithic digital patterning of polydimethylsiloxane with successive laser pyrolysis

The patterning of polydimethylsiloxane (PDMS) into complex two-dimensional (2D) or 3D shapes is a crucial step for diverse applications based on soft lithography. Nevertheless, mould replication that incorporates time-consuming and costly photolithography processes still remains the dominant technology in the field. Here we developed monolithic quasi-3D digital patterning of PDMS using laser pyrolysis. In contrast with conventional burning or laser ablation of transparent PDMS, which yields poor surface properties, our successive laser pyrolysis technique converts PDMS into easily removable silicon carbide via consecutive photothermal pyrolysis guided by a continuous-wave laser. We obtained high-quality 2D or 3D PDMS structures with complex patterning starting from a PDMS monolith in a remarkably low prototyping time (less than one hour). Moreover, we developed distinct microfluidic devices with elaborated channel architectures and a customizable organ-on-a-chip device using this approach, which showcases the potential of the successive laser pyrolysis technique for the fabrication of devices for several technological applications.

Demonstration of a ring-FEL as an EUV lithography tool

This paper presents the required structure and function of a ring-FEL as a radiation source for extreme ultraviolet radiation lithography (EUVL). A 100 m-long straight section that conducts an extremely low emittance beam from a fourth-generation storage ring can increase the average power at 13.5 nm wavelength to up to 1 kW without degrading the beam in the rest of the ring. Here, simulation results for a ring-FEL as a EUVL source are described.

A166 ANALYSIS OF SYMPTOMS, DIAGNOSTIC PATTERNS, AND CANADIAN PROVIDER PERSPECTIVE OF ACUTE HEPATIC PORPHYRIA

Background

Acute hepatic porphyria (AHP) is a family of rare genetic diseases, the most common being acute intermittent porphyria (AIP). AHP results from enzyme deficiencies involved in haem synthesis, leading to accumulation of neurotoxic haem intermediates, aminolaevulinic acid (ALA) and porphobilinogen (PBG), causing potentially life-threatening attacks and chronic symptoms. Patients afflicted by AHP often remain without a proper diagnosis for up to 15 years due to lack of awareness and testing. First-line diagnostic biochemical tests include measuring spot urinary ALA and PBG as both are elevated in the majority of AHP patients.

Aims

The study aimed to describe physicians experience diagnosing AHP and characterize patients globally, including Canada.

Methods

Physicians (n=175) who actively managed AHP patients (with and without recurrent attacks) in the preceding year were recruited from 9/2017–10/2017 to complete an online survey collecting information on demographics, familiarity with AHP and diagnostic tests, perspective on symptoms important to diagnosis, referral patterns, and treatment preferences. Physicians also completed a chart review of 546 patients and reported anonymized data on demographics, medical history, attacks, and symptoms. Data was analysed using descriptive statistics.

Results

Canadian physicians (n=15) practiced a mean of 19.7 years, 67% worked in community settings, and 53% were gastroenterologists. Symptoms informing AHP diagnosis included fatigue (93%), sensory loss (87%), mental confusion (87%), Abdominal pain (80%), red/dark urine (80%), vomiting (73%). AHP diagnostic tests considered informative for diagnosis included urinary ALA (87%) and PBG (80%); however, several non-specific tests were also commonly considered informative of AHP. Chronic symptoms reported included fatigue (75%), nausea/vomiting (70%), weakness (66%), pain (58%), anxiety (54%), diarrhea (41%), constipation (40%). Canadian physicians reported a mean of 58% AHP patients they manage being initially misdiagnosed. Global patients (n=546) were aged 40 years (mean), female (52%), with AIP (83%). Canadian patients (n=38) were aged 41 years (mean), female (61%), with AIP (78%). Patients had mean of 3.4 attacks and 1.6 hospitalizations in the past year.

Conclusions

This study highlights the challenges diagnosing AHP due to non-specificity of symptoms and limited understanding of diagnostic procedures. Due to the frequent presentation of gastrointestinal symptoms, AHP should be included in gastroenterologists’ differential diagnosis of patients presenting with non-specific abdominal pain. Among patients diagnosed with AHP, both acute attacks and chronic symptoms were reported, implicating both in the disease.

Funding Agencies

Alnylam Pharmaceuticals

P3466Cardiac output in end-stage liver disease increases with the severity of liver dysfunction

Background

End-stage liver disease is associated with significant systemic and haemodynamic alterations that affect cardiac function. Cirrhotic cardiomyopathy remains an ill-defined entity among cardiologists. Understanding the complex interplay between liver dysfunction and cardiac function can lead to a better understanding of the compensatory mechanisms of the heart in liver failure.

Purpose

To investigate whether severity of liver disease affects baseline cardiac output in a large contemporary cohort of patients undergoing liver transplant work-up.

Methods

Consecutive patients that underwent pre-liver transplant (LT) workup between 2010–2017 were included. All patients underwent a resting echocardiogram. Cardiac output (CO) was prospectively recorded at baseline by pulsed-wave Doppler examination of the left ventricular outflow tract from the apical window and systemic vascular resistance (SVR) was calculated as 80 x (mean arterial pressure (MAP)/CO). Severity of liver disease was characterized by the model of end-stage liver disease (MELD) and Child-Pugh scores.

Results

560 patients were included (mean age 57.5±7.7, 74.8% male). Mean MELD score was 19±7 and Child-Pugh Score was 9±3. There was an inverse linear relationship between the severity of liver disease by the MELD score and baseline SVR (rho 0.40, P<0.001). As SVR reduced, there was also a significant rise in baseline CO with a strong inverse correlation between the two variables (rho 0.86, p<0.001). There was a significant linear correlation between the severity of liver disease and baseline CO with both the scores (MELD Score rho 0.42, p<0.001; Child Pugh rho 0.44, p<0.001) (Figure).

Baseline CO in LT Patients by Severity

Conclusions

Baseline CO increased with the severity of liver dysfunction due to a reduced afterload. A higher resting CO may lead to patients encroaching on their cardiac reserve at rest. This provides a pathophysiological insight suggesting a limited role for beta-blockers, particularly in patients with advanced liver cirrhosis.

P3465Inducible left ventricular outflow tract obstruction is associated with a higher incidence of perioperative cardiac arrest in liver transplantation

Background

Inducible left ventricular outflow tract obstruction (LVOTO) is not infrequently encountered in liver transplant (LT) candidates undergoing cardiac workup. While the impact of LVOTO on adverse cardiovascular haemodynamics is well reported, it is unclear whether it predisposes to perioperative cardiovascular complications following LT.

Purpose

To investigate the effect of inducible left ventricular outflow tract obstruction on perioperative cardiovascular complications in a modern cohort of liver transplant patients.

Methods

Consecutive patients undergoing dobutamine stress echocardiography (DSE) were evaluated from a quaternary LT centre between 2010 and 2017. Inducible LVOTO was defined as LVOT gradient ≥36mmHg. Perioperative major adverse cardiovascular events (MACE) at 30 days and all-cause death were recorded from a prospectively maintained transplantation database and augmented by electronic medical record review.

Results

We evaluated 560 patients who underwent DSE as part of a workup for LT. Of these, 319 progressed to transplant. Inducible LVOTO was observed in 68 patients (21.3%). A higher baseline cardiac output (7.7 L/min vs 7.0 L/min, p=0.002) predicted for development of inducible LVOTO. Seventy-seven patients (4.1%) experienced a MACE including five deaths, 19 cases of heart failure, 11 cardiac arrests, 10 acute coronary syndromes and 46 cases of arrhythmias (VT/AF). Overall MACE occurred in 17/68 patients (25.0%) with LVOTO and 60/251 patients (23.9%) without LVOTO (p=0.85). However, there was a significantly increased risk of resuscitated perioperative cardiac arrest in patients with LVOTO (7.4% vs 2.4%, p=0.04). Patients with LVOTO also required significantly greater volumes of fluid intra-operatively (8.37L vs. 6.71L, p=0.043).

Cardiac Arrest in LT Patients with LVOTO

Conclusions

Inducible LVOTO is a frequent finding occurring in 21.3% of LT candidates. Despite higher intraoperative fluid resuscitation, LVOTO increased the risk of a perioperative cardiac arrest. Further studies are required to confirm these findings and to assess whether patients with LVOTO undergoing liver transplantation may benefit from heightened perioperative surveillance.

Tumor spheroid-on-a-chip: a standardized microfluidic culture platform for investigating tumor angiogenesis

The field of microfluidics-based three-dimensional (3D) cell culture system is rapidly progressing from academic proof-of-concept studies to valid solutions to real-world problems. Polydimethylsiloxane (PDMS)-based platform has been widely adopted as in vitro platforms for mimicking tumor microenvironment. However, PDMS has not been welcomed as a standardized commercial application for preclinical screening due to inherent material limitations that make it difficult to scale-up production. Here, we present an injection-molded plastic array 3D spheroid culture platform (Sphero-IMPACT). The platform is made of polystyrene (PS) in a standardized 96-well plate format with a user-friendly interface. This interface describes a simpler design that incorporates a tapered hole in the center of the rail to pattern a large spheroid with 3D extracellular matrix and various cell types. This hole is designed to accommodate standard pipette tip for automated system. The platform that mediate open microfluidics allows implement spontaneous fluid patterning with high repeatability from the end user. To demonstrate versatile use of the platform, we developed 3D perfusable blood vessel network and tumor spheroid assays. In addition, we established a tumor spheroid induced angiogenesis model that can be applicable for drug screening. Sphero-IMPACT has the potential to provide a robust and reproducible in vitro assay related to vascularized cancer research. This easy-to-use, ready-to-use platform can be translated into an enhanced preclinical model that faithfully reflects the complex tumor microenvironment.