Mesa+ Meeting

Thematic Sessions

1Early diagnostics of diseases, chaired by dr.ir. Loes Segerink & prof.dr.ir. Albert van den Berg

2Unconventional electronics, chaired by prof.dr.ir. Wilfred van der Wiel & prof.dr.ing. Guus Rijnders

3Storage and conversion of renewable energy, chaired by prof.dr. Guido Mul & dr.ir. Mark Huijben

4Water, chaired by prof.dr.ir. Rob Lammertink & dr.ir. Wiebe de Vos

Early diagnostics of diseases (ROOM 3)

Chairs: dr.ir. Loes Segerink (BIOS) & prof.dr.ir. Albert van den Berg (BIOS)

INTRODUCTION

Screening for diseases such as cancer could require nothing more than a finger prick, by analyzing a tiny drop of blood. It will allow physicians to diagnose the disease in an early stage, and as a result effective treatment can start. Such early detection requires very sensitive biosensors. 

In the past decade, both micro- and nanotechnology has accelerated the development of such biosensors, resulting in analytical and diagnostic lab-on-a-chip systems, which combine sample loading, delivery, sample preparation through mixing with reagents, and sensing components. Such systems, capable of performing diagnostic tests with low sample consumption and fast analysis, are a natural fit for point-of-care use, that is, diagnostics performed near the patient without the use of a clinical lab. It is expected that this will modernize future healthcare. Future early diagnostics applications, however, rely on the development of new innovative technologies for fabrication of biosensors as well as further understanding of their detection principles.

This session will give an overview of sensor based early diagnostics activities in MESA+ and its direct surroundings. Listeners will be stimulated to look for overlap in their own research activities, also in the light of interesting funding possibilities for early diagnostics-related research.

PROGRAM

ABSTRACTS

Laser-driven resonance of light-absorbing ultrasound contrast microbubbles

Dr. Guillaume Lajonie (POF)

The sensitivity of ultrasound imaging is greatly enhanced by the use of microbubble contrast agents through resonant volumetric oscillations. While the increased acoustic contrast is of prime interest for perfusion imaging of organs, microbubbles until now have limited benefit in terms of specificity for ultrasound imaging. Original strategies are required to tackle this difficulty that rely on loading functional targeting ligands onto the microbubble encapsulation. In parallel, another type of wave is used in biomedical imaging that shows great specificity in its interaction with tissue, namely light. This advantage is put to use in photoacoustic imaging where absorbed laser light is converted into a measurable acoustic signal. Here we present a novel ultrasound contrast agent designed to also make use of the superior specificity of laser light. The acoustic agent consists of a gas core encapsulated by an oil layer containing an optically absorbing dye. The resulting laser light absorption can then be used to heat up the gas and drive the system into resonance, thereby generating ultrasound. Combining finite difference simulations and ultra high-speed imaging led to a quantitative physical description of the optical and thermal interactions in the system resulting in the efficient generation of acoustic waves in the MHz range. A range of physical bubble parameters are investigated, in particular those related to the thickness and composition of the light absorbing oil layer. This new generation of contrast agents will open up new applications in medical diagnostic and therapeutic imaging.

Biosensor surface functionalization for sequence-specific DNA detection

Dr. Roberto Ricciardi (MnF)

Early diagnostics of cancer is gaining increasing attention not only among medical doctors, but also within academic and industrial research. Most of the scientific attention is being put on the development of screening tests which are as little invasive as possible, so that to increase the patient’s compliance. Hypermetilation of promoter regions of numerous genes has been associated with the onset of a variety of tumors. This epigenetic modification occurring at CpG motifs is linked to the silencing of tumor suppressor genes. Hypermethylated DNA can be present as cell-free DNA in body fluids such as blood, plasma, urine etc. The detection of hypermethylated DNA in urine unravel the possibility to non-invasively screen patients for many different kind of tumors. Herein, we present a number of strategies for the functionalization of a biosensor surface for sequence-specific detection of hypermetylated DNA. Surface chemistry ensures the right density of DNA probes, the specificity of the recognition process and improves the detection sensitivity.

Inkjet-printed diagnostics with integrated sample preparation

Dr.ir. Markus Beck (MCBP)

Simple and low cost point-of-care cell analysis is not only needed for some of the major global public health threats such as HIV, malaria and tuberculosis, but would also be valuable at the hospital bedside or at a general practitioner’s office. Our approach to realize point-of-care cytometry is to store cell staining reagents (e.g. fluorophore-labeled antibodies) inside a cell counting chamber and make sure that they are not washed off by the inflowing sample. We therefor embed the reagents in a dried hydrogel layer from which they are released after the inflow has stopped. To ensure that our CD4 count (a standard test for monitoring the disease state of HIV patients) can meet the stringent cost requirements for low-resource settings, we have developed printing processes to fabricate such chambers with on-chip sample preparation. We use printing techniques not only used for the deposition of the hydrogel layer, but also the chamber itself is produced by printing a mixture of UV-curable glue and 30 µm polystyrene beads as spacers between two microscope slides.

This presentations will provide an overview of our activities and discuss how this approach could contribute to early diagnostics of disease.

Title: tba

Dr. Srirang Manohar (BMPI)