Li Xiao

Abstract This paper reports an electrochemical microfluidic paper-based analytical device (EμPAD) for glucose detection, featuring a highly sensitive working electrode (WE) decorated with zinc oxide nanowires (ZnO NWs). In addition to the common features of μPADs, such as their low costs, high portability/disposability, and ease of operation, the reported EμPAD has three further advantages. (i) It provides higher sensitivity and a lower limit of detection (LOD) than previously reported μPADs because of the high surface-to-volume ratio and high enzyme-capturing efficiency of the ZnO NWs. (ii) It does not need any light-sensitive electron mediator (as is usually required in enzymatic glucose sensing), which leads to enhanced biosensing stability. (iii) The ZnO NWs are directly synthesized on the paper substrate via low-temperature hydrothermal growth, representing a simple, low-cost, consistent, and mass-producible process. To achieve superior analytical performance, the on-chip stored enzyme (glucose oxidase) dose and the assay incubation time are tuned. More importantly, the critical design parameters of the EμPAD, including the WE area and the ZnO-NW growth level, are adjusted to yield tunable ranges for the assay sensitivity and LOD. The highest sensitivity that we have achieved is 8.24 μA·mM −1 ·cm −2 , with a corresponding LOD of 59.5 μM. By choosing the right combination of design parameters, we constructed EμPADs that cover the range of clinically relevant glucose concentrations (0−15 mM) and fully calibrated these devices using spiked phosphate-buffered saline and human serum. We believe that the reported approach for integrating ZnO NWs on EμPADs could be well utilized in many other designs of EμPADs and provides a facile and inexpensive paradigm for further enhancing the device performance.

With increasing use of immunotherapy agents, pretreatment strategies for identifying responders and non-responders is useful for appropriate treatment assignment. We hypothesize that the local immune micro-environment of NSCLC is associated with patient outcomes and that these local immune features exhibit distinct radiologic characteristics discernible by quantitative imaging metrics. We assembled two cohorts of NSCLC patients treated with definitive surgical resection and extracted quantitative parameters from pretreatment CT imaging. The excised primary tumors were then quantified for percent tumor PDL1 expression and density of tumor-infiltrating lymphocyte (via CD3 count) utilizing immunohistochemistry and automated cell counting. Associating these pretreatment radiomics parameters with tumor immune parameters, we developed an immune pathology-informed model (IPIM) that separated patients into 4 clusters (designated A-D) utilizing 4 radiomics features. The IPIM designation was significantly associated with overall survival in both training (5 year OS: 61%, 41%, 50%, and 91%, for clusters A-D, respectively, P = 0.04) and validation (5 year OS: 55%, 72%, 75%, and 86%, for clusters A-D, respectively, P = 0.002) cohorts and immune pathology (all P < 0.05). Specifically, we identified a favorable outcome group characterized by low CT intensity and high heterogeneity that exhibited low PDL1 and high CD3 infiltration, suggestive of a favorable immune activated state. We have developed a NSCLC radiomics signature based on the immune micro-environment and patient outcomes. This manuscript demonstrates model creation and validation in independent cohorts.

UNLABELLED: The synthesis and validation of a new, highly potent (64)Cu-labeled peptide, cFLFLFK-PEG-(64)Cu, that targets the formyl peptide receptor (FPR) on leukocytes is described. The peptide ligand is an antagonist of the FPR, designed not to elicit a chemotactic response resulting in neutropenia. Evidence for the selective binding of this synthesized ligand to neutrophils is provided. PET properties of the compound were evaluated in a mouse model of lung inflammation. METHODS: The FPR-specific peptide, cinnamoyl-F-(D)L-F-(D)L-FK (cFLFLF), was sequentially conjugated with a bifunctional polyethylene glycol moiety (PEG, 3.4 kD) and a 2,2',2'',2'''-(1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrayl)tetraacetic acid (DOTA) through a lysine (K) spacer and finally labeled with (64)Cu-CuCl(2) to form cFLFLFK-PEG-(64)Cu. The binding affinity and stimulation potency of the ligand toward human neutrophils were assessed in vitro. Blood kinetic and organ biodistribution properties of the peptide were studied in the mouse. Ten male C57BL/6 mice were used in this study; 4 control mice and 6 administered Klebsiella pneumonia. PET/CT scans were performed to assess the localization properties of the labeled peptide in lungs 18 h after tracer administration. Lung standardized uptake values (SUVs) were correlated with lung neutrophil activity as measured by myeloperoxidase assays. Immunohistochemistry was performed to confirm that neutrophils constitute the majority of infiltrating leukocytes in lung tissue 24 h after Klebsiella exposure. RESULTS: In vitro binding assays of the compound cFLFLFK-PEG-(64)Cu to the neutrophil FPR yielded a dissociation constant of 17.7 nM. The functional superoxide stimulation assay exhibited negligible agonist activity of the ligand with respect to neutrophil superoxide production. The pegylated peptide ligand exhibited a blood clearance half-life of 55 +/- 8 min. PET 18 h after tracer administration revealed mean lung SUVs and lung myeloperoxidase activities for Klebsiella-infected mice that were 5- and 6-fold higher, respectively, than those for control mice. Immunohistochemistry staining confirmed that the cellular infiltrate in lungs of Klebsiella-infected mice was almost exclusively neutrophils at the time of imaging. CONCLUSION: This new radiolabeled peptide targeting the FPR binds to neutrophils in vitro and accumulates at sites of inflammation in vivo. This modified peptide may prove to be a useful tool to probe inflammation or injury.