iBB

The establishment of novel, simpler and improved purification processes is extremely important to make antibody-based treatment options more accessible and with a lower economic burden to healthcare systems and patients. In this context, the development of microfluidic tools for the optimization of chromatography operating conditions can offer advantages such as low consumption of molecules, fast generation of results and ability to automate and multiplex the assays. In a collaboration between INESC-MN and iBB, researchers have recently reported a novel microfluidics-based methodology to perform rapid and multiplexed screening of various chromatography ligands relative to their ability to bind different target molecules in solution. The work was published in the Biotechnology Journal and is expected to contribute to the fields of separation sciences and analytical chemistry and inspire new developments within the purification of biopharmaceuticals or other molecules.

Microfluidic devices with integrated photodetectors can address the need for compact and portable biosensing platforms for medical, veterinary, environmental and food safety applications. However, depending on the application, performance requirements like the minimum detectable limits, the target sensitivity, and the detection time can vary dramatically. To improve the engineering of fit-for-purpose bead-based microfluidic biosensors, researchers at BERG-iBB and INESC-MN developed a simple quantitative methodology to determine (1) equilibrium constants, (2) binding kinetics, (3) rate at which photons are generated/absorbed per captured molecule, and (4) molecular capture efficiencies. These parameters provide an effective trade-off between required sensitivity, cost effectiveness and assay complexity. This work was published in the IOP Journal of Micromechanics and Microengineering.

For half a century aqueous two-phase systems (ATPSs) have been applied for the extraction and purification of biomolecules. In spite of their simplicity, selectivity, and relatively low cost they have not been significantly employed for industrial scale bioprocessing. Recently their ability to be readily scaled and interface easily in single-use, flexible biomanufacturing has led to industrial re-evaluation of ATPSs. Researchers of the Bioseparation Engineering Laboratory at BERG-iBB together with Dr. James V. Alstine, a former principal scientist at GE Healthcare recently published a review in the Biotechnology Journal providing a new perspective over aqueous two-phase separations focusing on the strengths, weaknesses, opportunities and threats to this separation technique with an industrial perspective.

Rapid empirical optimization/screening of the partition of biomolecules in aqueous two-phase systems (ATPS) can be performed in microfluidic devices coupled with fluorescence microscopy. However, the effect of fluorescent tags on partition must be carefully evaluated to assess the validity of extrapolating the results to a situation where the molecules are unlabelled. To evaluate this influence, researchers from BERG-iBB and INESC-MN (Mariana São Pedro, Ana Azevedo, Maria Raquel Aires-Barros and Ruben Soares) carried out an ATPS study using both microtubes (batch) and microfluidic devices (continuous). IgG molecules were labelled with three fluorescent tags with different global charge and reactivity, namely BODIPY™ FL maleimide, Alexa Fluor® 430 NHS ester and BODIPY™ FL NHS ester. The thiol reactive BODIPY™ FL maleimide coupled with a reducing agent provided minimal bias relative to the native molecule in PEG-phosphate systems. The work was recently published in the Biotechnology Journal.

The 3-fold increase in global population within the last 70 years implies a demand for an equally fast paced global food trade. Thus, to assure high food safety standards and protect the consumers, simple, rapid and effective means of screening food contaminants are required to adequately enforce regulations. Towards this goal, researchers at BERG-iBB and INESC MN recently developed a lab-on-a-chip microfluidic device with integrated photodetectors, allowing the simultaneous immunodetection of three harmful fungal toxins in a single step, in less than one minute and at concentrations in the parts-per-billion range. The work was published in the Royal Society of Chemistry journal Lab on a Chip.

A joint publication of researchers from BERG-iBB and INESC-MN in the journal Lab-On-a-Chip describes a new method of integrating a liquid sample preparation step based on aqueous two-phase systems in continuous with an immunoassay. This was performed in microfluidic channels with a depth of 20 µm, four times thinner than the average human hair. The strategy allows simultaneous neutralization of matrix interferents, analyte concentration and detection in a single step, thus having great potential for rapid and sensitive point-of-need applications without the need for complex sample preparation procedures.  The work was performed in the context of Ruben Soares's PhD in Biotechnology (supervisors R Aires Barros, JP Conde). Click on the title to learn more.