Microfluidic device for robust generation of two-component liquid-in-air slugs with individually controlled composition.

Using liquid slugs as microreactors and microvessels enable precise control over the conditions of their contents on short-time scales for a wide variety of applications. Particularly for screening applications, there is a need for control of slug parameters such as size and composition. We describe a new microfluidic approach for creating slugs in air, each comprising a size and composition that can be selected individually for each slug.

Integrated microfluidic and imaging platform for a kinase activity radioassay to analyze minute patient cancer samples.

Oncogenic kinase activity and the resulting aberrant growth and survival signaling are a common driving force of cancer. Accordingly, many successful molecularly targeted anticancer therapeutics are directed at inhibiting kinase activity. To assess kinase activity in minute patient samples, we have developed an immunocapture-based in vitro kinase assay on an integrated polydimethylsiloxane microfluidics platform that can reproducibly measure kinase activity from as few as 3,000 cells.

Performance evaluation of PETbox: a low cost bench top preclinical PET scanner.

Purpose: PETbox is a low cost bench top preclinical PET scanner dedicated to pharmacokinetic and pharmacodynamic mouse studies. A prototype system was developed at our institute, and this manuscript characterizes the performance of the prototype system.

Procedures: The PETbox detector consists of a 20 × 44 bismuth germanate crystal array with a thickness of 5 mm and cross-section size of 2.

Tuning the serum persistence of human serum albumin domain III:diabody fusion proteins.

The long circulation persistence of human serum albumin (HSA) is enabled by its domain III (DIII) interaction with the neonatal Fc receptor (FcRn). A protein scaffold based on HSA DIII was designed. To modify the serum half life of the scaffold, residues H535, H510, and H464 were individually mutated to alanine.

Towards information processing from nonlinear physical chemistry: a synthetic electrochemical cognitive system.

It is evident that complex animate materials, which operate far from equilibrium, exhibit sensory responses to the environment through emergent patterns. Formation of such patterns is often the underlying mechanism of an active response to environmental changes and can be interpreted as a result of the distributed parallel information processing taking place within the material. Such emergent patterns are not limited to biological entities; indeed there is a wide range of complex nonlinear dissipative systems which exhibit interesting emergent patterns within a range of parameters.

The proximal signaling network of the BCR-ABL1 oncogene shows a modular organization.

BCR-ABL1 is a fusion tyrosine kinase, which causes multiple types of leukemia. We used an integrated proteomic approach that includes label-free quantitative protein complex and phosphorylation profiling by mass spectrometry to systematically characterize the proximal signaling network of this oncogenic kinase. The proximal BCR-ABL1 signaling network shows a modular and layered organization with an inner core of three leukemia transformation-relevant adaptor protein complexes (Grb2/Gab2/Shc1 complex, CrkI complex and Dok1/Dok2 complex).

Rank-rank hypergeometric overlap: identification of statistically significant overlap between gene-expression signatures.

Comparing independent high-throughput gene-expression experiments can generate hypotheses about which gene-expression programs are shared between particular biological processes. Current techniques to compare expression profiles typically involve choosing a fixed differential expression threshold to summarize results, potentially reducing sensitivity to small but concordant changes. We present a threshold-free algorithm called Rank-rank Hypergeometric Overlap (RRHO).

A microfluidic platform for systems pathology: multiparameter single-cell signaling measurements of clinical brain tumor specimens.

The clinical practice of oncology is being transformed by molecular diagnostics that will enable predictive and personalized medicine. Current technologies for quantitation of the cancer proteome are either qualitative (e.g.

Evaluation of two internalizing carcinoembryonic antigen reporter genes for molecular imaging.

Purpose: The objective of this article is to develop internalizing positron emission tomography (PET) reporter genes for tracking genetically modified T cells in vivo.

Procedures: The transmembrane and cytoplasmic domains of the human transferrin receptor (TfR) and CD5 were each fused to the carcinoembryonic (CEA) minigene N-A3 and expressed in Jurkat T cells. Internalization was evaluated by confocal microscopy or by intracellular uptake of ¹²⁵I-labeled anti-CEA scFv-Fc.

In vivo mouse bioluminescence tomography with radionuclide-based imaging validation.

Introduction: Bioluminescence imaging, especially planar bioluminescence imaging, has been extensively applied in in vivo preclinical biological research. Bioluminescence tomography (BLT) has the potential to provide more accurate imaging information due to its 3D reconstruction compared with its planar counterpart.

Methods: In this work, we introduce a positron emission tomography (PET) radionuclide imaging-based strategy to validate the BLT results.

An affinity matured minibody for PET imaging of prostate stem cell antigen (PSCA)-expressing tumors.

Purpose: Prostate stem cell antigen (PSCA), a cell surface glycoprotein expressed in normal human prostate and bladder, is over-expressed in the majority of localized prostate cancer and most bone metastases. We have previously shown that the hu1G8 minibody, a humanized anti-PSCA antibody fragment (single-chain Fv-C(H)3 dimer, 80 kDa), can localize specifically and image PSCA-expressing xenografts at 21 h post-injection. However, the humanization and antibody fragment reformatting decreased its apparent affinity.

Antibody vectors for imaging.

Noninvasive molecular imaging approaches include nuclear, optical, magnetic resonance imaging, computed tomography, ultrasound, and photoacoustic imaging, which require accumulation of a signal delivered by a probe at the target site. Monoclonal antibodies are high affinity molecules that can be used for specific, high signal delivery to cell surface molecules. However, their long circulation time in blood makes them unsuitable as imaging probes.

Maximal entropy inference of oncogenicity from phosphorylation signaling.

Point mutations in the phosphorylation domain of the Bcr-Abl fusion oncogene give rise to drug resistance in chronic myelogenous leukemia patients. These mutations alter kinase-mediated signaling function and phenotypic outcome. An information theoretic analysis of the correlation of phosphoproteomic profiling and transformation potency of the oncogene in different mutants is presented.

Integrated Microfluidic Reactors.

Microfluidic reactors exhibit intrinsic advantages of reduced chemical consumption, safety, high surface-area-to-volume ratios, and improved control over mass and heat transfer superior to the macroscopic reaction setting. In contract to a continuous-flow microfluidic system composed of only a microchannel network, an integrated microfluidic system represents a scalable integration of a microchannel network with functional microfluidic modules, thus enabling the execution and automation of complicated chemical reactions in a single device. In this review, we summarize recent progresses on the development of integrated microfluidics-based chemical reactors for (i) parallel screening of in situ click chemistry libraries, (ii) multistep synthesis of radiolabeled imaging probes for positron emission tomography (PET), (iii) sequential preparation of individually addressable conducting polymer nanowire (CPNW), and (iv) solid-phase synthesis of DNA oligonucleotides.

A small library of DNA-encapsulated supramolecular nanoparticles for targeted gene delivery.

We demonstrated a convenient, flexible and modular synthetic approach for preparation of a small library of DNA-encapsulated supramolecular nanoparticles SNPs superset DNA and RGD-SNPs superset DNA with different sizes and RGD target ligand coverage for targeted gene delivery.

Minibodies and Multimodal Chromatography Methods: A Convergence of Challenge and Opportunity.

This case study describes early phase purification process development for a recombinant anticancer minibody produced in mammalian cell culture. The minibody did not bind to protein A. Cation-exchange, anion-exchange, hydrophobic-interaction, and hydroxyapatite (eluted by phosphate gradient) chromatographic methods were scouted, but the minibody coeluted with BSA to a substantial degree on each.

Dual-energy attenuation coefficient decomposition with differential filtration and application to a microCT scanner.

Dual-energy x-ray computed tomography (DECT) has the capability to decompose attenuation coefficients using two basis functions and has proved its potential in reducing beam-hardening artifacts from reconstructed images. The method typically involves two successive scans with different x-ray tube voltage settings. This work proposes an approach to dual-energy imaging through x-ray beam filtration that requires only one scan and a single tube voltage setting.

ImmunoPET imaging of B-cell lymphoma using 124I-anti-CD20 scFv dimers (diabodies).

Rapid clearing engineered antibody fragments for immunoPET promise high sensitivity at early time points. Here, tumor targeting of anti-CD20 diabodies (scFv dimers) for detection of low-grade B-cell lymphomas were evaluated. In addition, the effect of linker length on oligomerization of the diabody was investigated.

A Parallel Adaptive Finite Element Method for the Simulation of Photon Migration with the Radiative-Transfer-Based Model.

Whole-body optical molecular imaging of mouse models in preclinical research is rapidly developing in recent years. In this context, it is essential and necessary to develop novel simulation methods of light propagation for optical imaging, especially when a priori knowledge, large-volume domain and a wide-range of optical properties need to be considered in the reconstruction algorithm. In this paper, we propose a three dimensional parallel adaptive finite element method with simplified spherical harmonics (SP(N)) approximation to simulate optical photon propagation in large-volumes of heterogenous tissues.

Cerenkov radiation imaging as a method for quantitative measurements of beta particles in a microfluidic chip.

It has been observed that microfluidic chips used for synthesizing (18)F-labeled compounds demonstrate visible light emission without nearby scintillators or fluorescent materials. The origin of the light was investigated and found to be consistent with the emission characteristics from Cerenkov radiation. Since (18)F decays through the emission of high-energy positrons, the energy threshold for beta particles, i.

Spectrally resolved bioluminescence tomography with the third-order simplified spherical harmonics approximation.

Bioluminescence imaging has been extensively applied to in vivo small animal imaging. Quantitative three-dimensional bioluminescent source information obtained by using bioluminescence tomography can directly and much more accurately reflect biological changes as opposed to planar bioluminescence imaging. Preliminary simulated and experimental reconstruction results demonstrate the feasibility and promise of bioluminescence tomography.

Experimental bioluminescence tomography with fully parallel radiative-transfer-based reconstruction framework.

Bioluminescence imaging is a very sensitive imaging modality, used in preclinical molecular imaging. However, in its planar projection form, it is non-quantitative and has poor spatial resolution. In contrast, bioluminescence tomography (BLT) promises to provide three dimensional quantitative source information.

Recombinant anti-CD20 antibody fragments for small-animal PET imaging of B-cell lymphomas.

Unlabelled: The CD20 cell surface antigen is expressed at high levels by over 90% of B-cell non-Hodgkin lymphomas (NHL) and is the target of the anti-CD20 monoclonal antibody rituximab. To provide more sensitive, tumor-specific PET imaging of NHL, we sought to develop PET agents targeting CD20.

Methods: Two recombinant anti-CD20 rituximab fragments, a minibody (scFv-C(H)3 dimer; 80 kDa) and a modified scFv-Fc fragment (105 kDa), designed to clear rapidly, were generated.