Porcine Lung Tissue Research Articles

Microwave dielectric properties of normal, fibroelastotic, and malignant human lung tissue

Technological development of microwave treatment and detection techniques for lung cancer requires accurate and comprehensive knowledge of the microwave dielectric properties of human lung tissue. We characterize the dielectric properties of room temperature human lung tissue from 0.5 to 10 GHz for three lung tissue groups: normal, fibroelastotic, and malignant. We fit a two-pole Debye model to the measured frequency-dependent complex permittivity and calculate the median Debye parameters for the three groups. We find that malignant lung tissue is approximately 10% higher in relative permittivity and conductivity compared to normal lung tissue; this trend matches previously reported normal versus malignant data for other biological tissues. There is little contrast between benign lung tissue with fibroelastosis and malignant lung tissue. We extrapolate our data from room temperature to 37 °C using a temperature-dependence model for animal lung tissue and use the Maxwell-Garnett dielectric mixing model to predict the dielectric properties of inflation-dynamic human lung tissue; both approximations correspond with previously reported dielectric data of bovine and porcine lung tissue.

New insight on porcine carboxylesterases expression and activity in lung tissues

Over the course of the last twenty years, there has been a growing recognition of the pig's potential as a valuable model for studying human drug metabolism. This study aimed to investigate the expression, enzymatic activity, inhibitory susceptibility, and cellular localization of carboxylesterases (CES) in porcine lung tissue not yet explored. Our results showed that CESs hydrolysis activity followed Michaelis-Menten kinetics in both cytosolic and microsomal fractions of porcine lung tissues (N = 8), with comparable hydrolysis rates for tested substrates, namely 4-nitrophenyl acetate (pNPA), 4-methylumbelliferyl acetate (4-MUA), and fluorescein diacetate (FD). We also determined the CESs hydrolysis activity in a representative sample of the porcine liver that, as expected, displayed higher activity than the lung ones. The study demonstrated variable levels of enzyme activities and interindividual variability in both porcine lung fractions. Inhibition studies used to assess the CESs' involvement in the hydrolysis of pNPA, 4-MUA, and FD suggested that CESs may be the enzymes primarily involved in the metabolism of ester compounds in the pig lung tissue. Overall, this study provides insight into the distribution and diversity of CES isoforms involved in substrate hydrolysis across different cellular fractions (cytosol and microsomes) in porcine lungs.

Porcine lung tissue slices: a culture model for PRCV infection and innate immune response investigations

Respiratory coronaviruses (RCoVs) significantly threaten human health, necessitating the development of an ex vivo respiratory culture system for investigating RCoVs infection. Here, we successfully generated a porcine precision-cut lung slices (PCLSs) culture system, containing all resident lung cell types in their natural arrangement. Next, this culture system was inoculated with a porcine respiratory coronavirus (PRCV), exhibiting clinical features akin to humans who were infected by SARS-CoV-2. The results demonstrated that PRCV efficiently infected and replicated within PCLSs, targeting ciliated cells in the bronchioles, terminal bronchioles, respiratory bronchioles, and pulmonary alveoli. Additionally, through RNA-Seq analysis of the innate immune response in PCLSs following PRCV infection, expression levels of interferons, inflammatory cytokines and IFN stimulated genes were significantly upregulated. This ex vivo model may not only offer new insights into PRCV infection in the porcine respiratory tract but also serve as a valuable tool for studying human respiratory CoVs infection.

High resolution fluorescence imaging of the alveolar scaffold as a novel tool to assess lung injury

Acute lung injury (ALI) represents an aetiologically diverse form of pulmonary damage. Part of the assessment and diagnosis of ALI depends on skilled observer-based scoring of brightfield microscopy tissue sections. Although this readout is sufficient to determine gross alterations in tissue structure, its categorical scores lack the sensitivity to describe more subtle changes in lung morphology. To generate a more sensitive readout of alveolar perturbation we carried out high resolution immunofluorescence imaging on 200 μm lung vibratome sections from baseline and acutely injured porcine lung tissue, stained with a tomato lectin, Lycopersicon Esculentum Dylight-488. With the ability to resolve individual alveoli along with their inner and outer wall we generated continuous readouts of alveolar wall thickness and circularity. From 212 alveoli traced from 10 baseline lung samples we established normal distributions for alveolar wall thickness (27.37; 95% CI [26.48:28.26]) and circularity (0.8609; 95% CI [0.8482:0.8667]) in healthy tissue. Compared to acutely injured lung tissue baseline tissue exhibited a significantly lower wall thickness (26.86 ± 0.4998 vs 50.55 ± 4.468; p = 0.0003) and higher degree of circularityϕ≤ (0.8783 ± 0.01965 vs 0.4133 ± 0.04366; p < 0.0001). These two components were subsequently combined into a single more sensitive variable, termed the morphological quotient (MQ), which exhibited a significant negative correlation (R2 = 0.9919, p < 0.0001) with the gold standard of observer-based scoring. Through the utilisation of advanced light imaging we show it is possible to generate sensitive continuous datasets describing fundamental morphological changes that arise in acute lung injury. These data represent valuable new analytical tools that can be used to precisely benchmark changes in alveolar morphology both in disease/injury as well as in response to treatment/therapy.

The avian influenza A virus receptor SA-α2,3-Gal is expressed in the porcine nasal mucosa sustaining the pig as a mixing vessel for new influenza viruses

Influenza A viruses (IAVs) originate from wild birds but have on several occasions jumped host barriers and are now also circulating in humans and mammals. The IAV host receptors (glycans with galactose linked to a sialic acid (SA) in an α2,3 or α2,6 linkage) are crucial host factors restricting inter-species transmission. In general, avian-origin IAVs show a preference for SA-α2,3 (avian receptor), whereas IAVs isolated from humans and pigs prefer SA-α2,6 (human receptor). N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc) are the two major SAs. Neu5Ac is expressed in all species, whereas Neu5Gc is only expressed in a limited number of domestic species such as pigs and horses, but not in humans. Despite that previous studies have shown that the IAV host receptor distribution appears to be similar in pigs and humans, none of these studies have investigated the expression of Neu5Gc-α2,6 in situ in porcine tissues. Thus, the aim of this study was to elucidate the distribution of IAV host receptors expressed in the porcine respiratory tract and relate the expression to the viral tropism of diverse host-adapted IAVs.The IAV receptor (SA-α2,3 and SA-α2,6) distribution and the presence of specifically Neu5Gc-α2,6 in the porcine nasal, tracheal, and lung tissues was investigated by lectin histochemistry. Furthermore, IAV immunohistochemistry was performed on tissues from pigs experimentally infected with IAVs, either adapted to pigs or humans, to investigate the significance of the IAV host receptors and the tropism of the diverse host-adapted IAVs. We document for the first time the expression of the avian receptor on the surface of the porcine nasal mucosa and an equal expression of Neu5Ac- α2,6 and Neu5Gc-α2,6 on the surface of the tracheal epithelium and alveoli. In all IAV-infected pigs, we found a low amount of IAV-positive cells in the trachea despite a high expression of the human receptor. Cumulatively, these findings suggest that optimal IAV replication involves a complex interplay between the viruses and their host receptors and that there might be other less clearly defined host factors that determine the site of replication.

Identification of the novel potential pathogen Trueperella pecoris with interspecies significance by LAMP diagnostics

Trueperella pecoris was described as a new species of the genus Trueperella in 2021 and might be pathogenic to various animal species. However, the lack of a suitable diagnostic test system stands in the way of epidemiological surveys to clarify possible causalities. In this study, a Loop-mediated Isothermal Amplification (LAMP) assay was developed and validated that was highly specific for T. pecoris. The assay provided an analytical sensitivity of 0.5 pg/25 µL and showed 100% inclusivity and exclusivity for 11 target and 33 non-target strains, respectively. Three different DNA extraction methods were evaluated to select the most LAMP-compatible method for cell disruption in pure and complex samples. Using an on-site applicable single-buffer DNA extraction with additional heating, the cell-based detection limit was 2.3 CFU/reaction. Finally, the LAMP assay was validated by means of artificially contaminated porcine lung tissue samples in which minimal microbial loads between 6.54 and 8.37 × 103 CFU per swab sample were detectable. The LAMP assay established in this study represents a suitable diagnostic procedure for identifying T. pecoris in clinical specimens and will help to collect epidemiological data on the pathogenicity of this species.

Compression Behavior of Extra-soft Porcine Lung Tissue at the Wide Strain Rate

Lung is the respiratory organ and the important hematopoietic organ of the human body, which is easily damaged under impact load. Therefore, studying the mechanical behavior of the lung under impact load is an important way to understand its damage mechanism of it. Compression experiments of porcine lung tissue at a wide strain rate (0.001-3000 s−1) were carried out at room temperature. The modifications were made for the highly accurate mechanical measurement of the tissue due to its low wave impedance. The results show that its behaviors consist of three stages, linear elasticity, plateau stage, and compaction. The lung tissue presents distinct rate-dependence in the compaction stage. Furthermore, it behaves nearly similarly under both the loading directions of vertical and parallel trachea, which facilitates to a demonstration of its isotropy.

Metabolomic fingerprinting of porcine lung tissue during pre-clinical prolonged ex vivo lung perfusion using in vivo SPME coupled with LC-HRMS

Normothermic ex vivo lung perfusion (NEVLP) has emerged as a modernized organ preservation technique that allows for detailed assessment of donor lung function prior to transplantation. The main goal of this study was to identify potential biomarkers of lung function and/or injury during a prolonged (19 h) NEVLP procedure using in vivo solid-phase microextraction (SPME) technology followed by liquid chromatography-high resolution mass spectrometry (LC-HRMS). The use of minimally invasive in vivo SPME fibers for repeated sampling of biological tissue permits the monitoring and evaluation of biochemical changes and alterations in the metabolomic profile of the lung. These in vivo SPME fibers were directly introduced into the lung and were also used to extract metabolites (on-site SPME) from fresh perfusate samples collected alongside lung samplings. A subsequent goal of the study was to assess the feasibility of SPME as an in vivo method in metabolomics studies, in comparison to the traditional in-lab metabolomics workflow. Several upregulated biochemical pathways involved in pro- and anti-inflammatory responses, as well as lipid metabolism, were observed during extended lung perfusion, especially between the 11th and 12th hours of the procedure, in both lung and perfusate samples. However, several unstable and/or short-lived metabolites, such as neuroprostanes, have been extracted from lung tissue in vivo using SPME fibers. On-site monitoring of the metabolomic profiles of both lung tissues through in vivo SPME and perfusate samples on site throughout the prolonged NEVLP procedure can be effectively performed using in vivo SPME technology.

M6A Demethylase ALKBH5 Restrains PEDV Infection by Regulating GAS6 Expression in Porcine Alveolar Macrophages.

Porcine epidemic diarrhea virus (PEDV) is a burdensome coronavirus for the global pig industry. Although its fecal-oral route has been well-recognized, increasing evidence suggests that PEDV can also spread through airborne routes, indicating that the infection may also occur in the respiratory tract. N6-methyladenosine (m6A) has been known to regulate viral replication and host immunity, yet its regulatory role and molecular mechanism regarding PEDV infection outside the gastrointestinal tract remain unexplored. In this study, we demonstrate that PEDV can infect porcine lung tissue and the 3D4/21 alveolar macrophage cell line, and the key m6A demethylase ALKBH5 is remarkably induced after PEDV infection. Interestingly, the disruption of ALKBH5 expression remarkably increases the infection’s capacity for PEDV. Transcriptome profiling identified dozens of putative targets of ALKBH5, including GAS6, which is known to regulate virus infectivity. Further, MeRIP-qPCR and mRNA stability analyses suggest that ALKBH5 regulates the expression of GAS6 via an m6A-YTHDF2-dependent mechanism. Overall, our study demonstrates that PEDV can infect porcine lung tissue and 3D4/21 cells and reveals the crucial role of ALKBH5 in restraining PEDV infections, at least partly, by influencing GAS6 through an m6A-YTHDF2-dependent mechanism.

AMG487 inhibits PRRSV replication and ameliorates lung injury in pig lung xenografts by down-regulating the expression of ANXA2

Porcine reproductive and respiratory syndrome (PRRS) is a pig disease caused by the PRRS virus (PRRSV) that is characterized with diffuse interstitial pneumonia and lung edema. High expressions of chemokine CXCL10 and its receptor CXCR3 are reported in infected porcine lungs. Since CXCR3 is a key player in host inflammatory response, it might be a therapeutic target to treat lung damage caused by PRRSV infection. The size of pigs has long hampered research into molecular mechanisms of PRRS and validating the potential pharmaceutical targets. In this study, a porcine lung xenograft model with PRRSV infection was generated in immunodeficient mice to evaluate the therapeutic effects of the CXCR3 antagonist AMG487 on PRRSV infection-induced lung injury. The porcine lung tissues developed normally two weeks after xeno-transplantation in the mouse kidney capsule. Infection of PRRSV resulted in its efficient replication in the xenografts and histological damage to the porcine lung tissue structure, with no or little effects on mouse lungs. AMG487 administration dramatically reduced the number of PRRSV genome copies and significantly alleviated the porcine lung injury. Furthermore, treatment of AMG487 in cultured porcine macrophages consistently suppressed PRRSV replication with significant downregulation of Annexin A2 (ANXA2), a cellular protein facilitating viral replication. These findings provide a suitable model for evaluating new antiviral therapies as well as a possible therapeutic option for virus infection-induced lung injury.

Quantitative proteomics reveals tissue-specific toxic mechanisms for acute hydrogen sulfide-induced injury of diverse organs in pig

Hydrogen sulfide (H2S) is a highly toxic gas in many environmental and occupational places. It can induce multiple organ injuries particularly in lung, trachea and liver, but the relevant mechanisms remain poorly understood. In this study, we used a TMT-based discovery proteomics to identify key proteins and correlated molecular pathways involved in the pathogenesis of acute H2S-induced toxicity in porcine lung, trachea and liver tissues. Pigs were subjected to acute inhalation exposure of up to 250 ppm of H2S for 5 h for the first time. Changes in hematology and biochemical indexes, serum inflammatory cytokines and histopathology demonstrated that acute H2S exposure induced organs inflammatory injury and dysfunction in the porcine lung, trachea and liver. The proteomic data showed 51, 99 and 84 proteins that were significantly altered in lung, trachea and liver, respectively. Gene ontology (GO) annotation, KEGG pathway and protein-protein interaction (PPI) network analysis revealed that acute H2S exposure affected the three organs via different mechanisms that were relatively similar between lung and trachea. Further analysis showed that acute H2S exposure caused inflammatory damages in the porcine lung and trachea through activating complement and coagulation cascades, and regulating the hyaluronan metabolic process. Whereas antigen presentation was found in the lung but oxidative stress and cell apoptosis was observed exclusively in the trachea. In the liver, an induced dysfunction was associated with protein processing in the endoplasmic reticulum and lipid metabolism. Further validation of some H2S responsive proteins using western blotting indicated that our proteomics data were highly reliable. Collectively, these findings provide insight into toxic molecular mechanisms that could potentially be targeted for therapeutic intervention for acute H2S intoxication.

Rapid Detection and Typing of Actinobacillus pleuropneumoniae Serovars Directly From Clinical Samples: Combining FTA® Card Technology With Multiplex PCR.

Actinobacillus pleuropneumoniae (APP), the causative agent of porcine pleuropneumonia, is highly contagious and responsible for high morbidity, mortality, and economic losses in the swine industry worldwide, but quick serotyping and diagnosis are still not widely available. In this study, we sought to validate the use of Whatman FTA® cards for collection and processing of A. pleuropneumoniae isolates, or porcine lung tissue samples, for direct use in diagnostic multiplex PCRs. We have optimized the processing of 3-mm discs punched from FTA® cards loaded with cultured A. pleuropneumoniae, or imprinted on lesioned regions of lung tissue, with only three distilled water washes before addition into our APP-multiplex PCR (mPCR) assay for rapid, low-cost identification and serotyping. DNA captured on FTA® cards generated the same diagnostic PCR results as DNA extracted using commercial kits for 85 A. pleuropneumoniae clinical isolate cultures and 22 lung samples. Additionally, bacterial DNA bound to FTA® cards was detectable by PCR after 6 months of storage at 37°C. This study provides simple, efficient, rapid, and practical sample processing for detection and molecular serotyping of A. pleuropneumoniae.

Engineered mucoadhesive microparticles of formoterol/budesonide for pulmonary administration

In the present study, a multi-component system comprised of dipalmitylphospatidylcholine (DPPC), Chitosan, Lactose, and L-Leucine was developed for pulmonary delivery. Microparticles were engineered by the spray drying process and the selection of the critical parameters was performed by applying experimental design. The microcarriers with the appropriate size and yield were co-formulated with two active pharmaceutical ingredients (APIs), namely, Formoterol fumarate and Budesonide, and they were further investigated. All formulations exhibited spherical shape, appropriate aerodynamic performance, satisfying entrapment efficiency, and drug load. Their physicochemical properties were evaluated using Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), and Differential Scanning Calorimetry (DSC). The aerodynamic particle size characterization was determined using an eight-stage Andersen cascade impactor, whereas the release of the actives was monitored in vitro in simulated lung fluid. Additional evaluation of the microparticles’ mucoadhesive properties was performed by ζ-potential measurements and ex vivo mucoadhesion study applying a falling liquid film method using porcine lung tissue. Cytotoxicity and cellular uptake studies in Calu-3 lung epithelial cell line were conducted to further investigate the safety and efficacy of the developed formulations.

Molecular and functional characterization of HtrA protein in Actinobacillus pleuropneumoniae

Actinobacillus pleuropneumoniae (A.pleuropneumoniae) causes serious economic loss for the swine industry. A high-temperature requirements A (HtrA)-like protease and its homologs have been reported to be involved in protein quality control and expression of important immunoprotective antigens in many pathogens. In this study, we showed that HtrA of A.pleuropneumoniae exhibited both chaperone and proteolytic activities. Moreover, Outer membrane protein P5 (OmpP5) in A.pleuropneumoniae and Heat shock protein 90 (Hsp90) in porcine lung tissues were first discovered and identified as specific proteolytic substrates for rHtrA. The maximum cleavage activity occurs at 50 ℃ in a time-dependent manner. In addition, rHtrA mainly induced IgG 2a subtype of IgG and Th1 (IFN-γ, IL-2) response in a mice model, and promoted a significant proliferation of spleen lymphocytes compare with negative control (P < 0.05). The survival rates of 37.5 % were observed against A.pleuropneumoniae strain. Together, these data demonstrate that rHtrA plays a multi-functional role in A.pleuropneumoniae.

Streptococcus suis Induces Expression of Cyclooxygenase-2 in Porcine Lung Tissue.

Streptococcus suis is a common pathogen colonising the respiratory tract of pigs. It can cause meningitis, sepsis and pneumonia leading to economic losses in the pig industry worldwide. Cyclooxygenase-2 (COX-2) and its metabolites play an important regulatory role in different biological processes like inflammation modulation and immune activation. In this report we analysed the induction of COX-2 and the production of its metabolite prostaglandin E2 (PGE2) in a porcine precision-cut lung slice (PCLS) model. Using Western blot analysis, we found a time-dependent induction of COX-2 in the infected tissue resulting in increased PGE2 levels. Immunohistological analysis revealed a strong COX-2 expression in the proximity of the bronchioles between the ciliated epithelial cells and the adjacent alveolar tissue. The morphology, location and vimentin staining suggested that these cells are subepithelial bronchial fibroblasts. Furthermore, we showed that COX-2 expression as well as PGE2 production was detected following infection with two prevalent S. suis serotypes and that the pore-forming toxin suilysin played an important role in this process. Therefore, this study provides new insights in the response of porcine lung cells to S. suis infections and serves as a basis for further studies to define the role of COX-2 and its metabolites in the inflammatory response in porcine lung tissue during infections with S. suis.

Development and Validation of a Bioanalytical LC-MS/MS Method for Simultaneous Determination of Sirolimus in Porcine Whole Blood and Lung Tissue and Pharmacokinetic Application with Coronary Stents.

Sirolimus is a hydrophobic macrolide compound that has been used for long-term immunosuppressive therapy, prevention of restenosis, and treatment of lymphangioleiomyomatosis. In this study, a simple and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed and validated for the simultaneous determination of sirolimus in both porcine whole blood and lung tissue. Blood and lung tissue homogenates were deproteinized with acetonitrile and injected into the LC-MS/MS system for analysis using the positive electrospray ionization mode. The drug was separated on a C18 reversed phase column with a gradient mobile phase (ammonium formate buffer (5 mM) with 0.1% formic acid and acetonitrile) at 0.2 mL/min. The selected reaction monitoring transitions of m/z 931.5 → 864.4 and m/z 809.5 → 756.5 were applied for sirolimus and ascomycin (the internal standard, IS), respectively. The method was selective and linear over a concentration range of 0.5–50 ng/mL. The method was validated for sensitivity, accuracy, precision, extraction recovery, matrix effect, and stability in porcine whole blood and lung tissue homogenates, and all values were within acceptable ranges. The method was applied to a pharmacokinetic study to quantitate sirolimus levels in porcine blood and its distribution in lung tissue following the application of stents in the porcine coronary arteries. It enabled the quantification of sirolimus concentration until 2 and 14 days in blood and in lung tissue, respectively. This method would be appropriate for both routine porcine pharmacokinetic and bio-distribution studies of sirolimus formulations.

Comparison of cryoprotective methods for histological examination of rat and porcine lung tissue

Proper histological evaluation of lung tissue and accurate antigen detection by immunodetection techniques require histological tissue processing to preserve tissue reactivity and open alveolar spaces. In this study, we focused on testing and comparing different procedures of tissue cryopreservation. Sucrose or Tissue Tek were used with several methods of freezing samples by supercooled liquids and liquid nitrogen. Changes in tissue caused during the freezing of samples and the effect of cryoprotectants on the tissue were recorded. Rat and porcine pulmonary tissues were used in this experiment. This study aimed to optimize the process of lung cryopreservation with emphasis on enabling proper anatomical evaluation and preserving a high tissue immunoreactivity. The best results were obtained by inflating pulmonary parenchyma with a 1 : 1 mixture of O.C.T. with phosphate buffered saline (PBS) frozen in supercooled n-heptane placed on dry ice. Pulmonary tissue prepared in this way enables to perform proper histological evaluation and to detect target molecules by immunohistochemical analysis.

Development of an analytical method for the determination of tulathromycin in porcine lung tissue using liquid chromatography-tandem mass spectrometry

This study investigated the residue of tulathromycin (TLM) on the lung tissue of pigs intramuscularly injected with 2.5 mg/kg body weight as a single dose. Nine healthy cross swine were intramuscularly injected with the drug. Three treated animals were arbitrarily selected to be sacrificed at 7, 10 and 14 days after treatment. TLM residue concentrations in lung tissue were determined using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The drug was extracted from lung samples using acetonitrile followed by clean-up with n-hexane. The analyte was separated on a Hypersil GOLDTM liquid chromatography column using 0.1% formic acid in deionized distilled water and acetonitrile. The correlation coefficient (R2) of the calibration curve was 0.9981, and the limits of detection and quantification were 10 and 50 μg/kg, respectively. Recoveries at three spiking levels ranged between 95.0-98.2%, and relative standard deviations were less than 3.95%. In TLM-treated group, the concentration of TLM on 7, 10 and 14 days post-treatment was 627.3, 496.9, 259.1 μg/kg, respectively. The developed method is sensitive and reliable for detection of TLM in porcine lung tissues. In addition, it can detect below the maximum residue limits in animal-derived food products destined for human consumption.

Abstract LB-285: Rapid needle biopsy assessment at point of care to advance personalized cancer therapy

Abstract Rationale: Although core needle biopsies (CNBs) are the preferred minimally invasive procedure for breast cancer diagnostics, the standard of care H&amp;E histopathologic analysis of core biopsies is both tissue destructive and labor intensive. Our novel millifluidic instrument, CoreView, is designed to evaluate fresh CNBs to make a real time cancer diagnosis or adequacy determination, conserve tissue for downstream diagnostics and assist in timely treatment planning. Technology and Methods: CoreView is designed to handle, stain, and transport CNBs with the use of millifluidics. The first stage of the CoreView removes biopsy procured tissue from side-cut and end-cut needle-type biopsy guns (14-16 gauge). The reliability of the novel low pressure fluidic process in removing intact CNBs was tested using freshly-excised (ex-vivo) porcine breast (N = 28), kidney (N = 21), liver (N = 42), lung (N = 25), and lymph node (N = 30) tissue. The shear rate, provided by the driving pressure of saline solution, was increased in increments until the CNB was removed and the resulting intactness was qualitatively analyzed by preserved overall shape and size. For optical imaging, a second stage streams fluorescence dye over the CNB for H&amp;E equivalent staining. High resolution imaging with 285 nm excitation is currently performed using microscopy with UV-surface excitation [MUSE, Levenson Group, UC Davis] for anatomical imaging. Previous studies have shown the optical sectioning thickness of MUSE is about 3x thicker than microtome-sectioned specimens. To improve the quality of images produced by MUSE within CoreView, we are limiting UV tissue penetration by steric hindrance of dye molecules using conjugated nanoparticles, such as 525-705 nm CdSe Qdots [ThermoFisher], as well as optical blocking dyes as counterstains. Results: The CNB removal stage was 3D-printed in a patent pending disposable design which is optically clear for monitoring the process. CNBs were fully released and structurally intact for analysis in 93% breast, 100% kidney, 100% liver, 84% lung, and 90% lymph node CNB samples. The average volume per time (µL/ms), an analog to shear rate, for each tissue type was 2.19 (σ;; = 1.04), 1.97 (σ;; =0.71), 1.74 (σ;; = 0.87), 2.05 (σ;; = 0.87), and 2.01 (σ;; = 0.87) for breast, kidney, liver, lung, and lymph node, respectively. The CNB tissue was removed in under 15 seconds, some as quickly as 2 seconds. Furthermore, the device's round channel, which holds a CNB with diameter 10-20% less than the channel, results in inherent structural preservation. Conclusions: The novel millifluidic biopsy removal device is an essential first stage to CoreView's automated biopsy handling and future MUSE imaging and adequacy analysis. The customizable CoreView system design allows optimization for specific CNB needle, tissue, and imaging procedure. We predict an adequacy check at nearly 100% reliability in CNB release and integrity within a few minutes at the point of care. Citation Format: David J. Cooper, Mark E. Fauver, Suzanne M. Dintzis, Eric J. Seibel. Rapid needle biopsy assessment at point of care to advance personalized cancer therapy [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr LB-285.

Broadband lung dielectric properties over the ablative temperature range: Experimental measurements and parametric models.

Computational models of microwave tissue ablation are widely used to guide the development of ablation devices, and are increasingly being used for the development of treatment planning and monitoring platforms. Knowledge of temperature-dependent dielectric properties of lung tissue is essential for accurate modeling of microwave ablation (MWA) of the lung. We employed the open-ended coaxial probe method, coupled with a custom tissue heating apparatus, to measure dielectric properties of ex vivo porcine and bovine lung tissue at temperatures ranging between 31 and 150 C, over the frequency range 500MHz to 6GHz. Furthermore, we employed numerical optimization techniques to provide parametric models for characterizing the broadband temperature-dependent dielectric properties of tissue, and their variability across tissue samples, suitable for use in computational models of microwave tissue ablation. Rapid decreases in both relative permittivity and effective conductivity were observed in the temperature range from 94 to 108 C. Over the measured frequency range, both relative permittivity and effective conductivity were suitably modeled by piecewise linear functions [root mean square error (RMSE)=1.0952 for permittivity and 0.0650 S/m for conductivity]. Detailed characterization of the variability in lung tissue properties was provided to enable uncertainty quantification of models of MWA. The reported dielectric properties of lung tissue, and parametric models which also capture their distribution, will aid the development of computational models of microwave lung ablation.