iBB

Materials with novel and enhanced functionalities can be obtained by modifying cellulose with a range of biomolecules. In a recent paper published in Materials, Mariana Barbosa, Hélvio Simões and Miguel Prazeres from BERG-iBB describe the modification of cellulose hydrogels using bi-functional biomolecular constructs based on carbohydrate binding modules (CBMs). The binding of CBM fusions, the capture of antibodies and the grafting of oligonucleotides onto hydrogels was successfully demonstrated. The CBM-based platform could contribute significantly to the development of advanced medical diagnostic sensors or specialized biomaterials, among others. The work was funded by project CBM-X.

BERG-iBB researchers led by Miguel Prazeres are developing biomolecular constructs for the precise modification of cellulose matrices with nanostructures and/or biomolecules. The back cover image of the August issue of Biotechnology Journal highlights a recent contribution of the group. The work is part of the FCT-funded project CBM-X.

The project "CBM-X: Biorecognition as a Tool for the Functionalization of Cellulose-based Materials with Biomolecules and Nanostructures" has been recommended for funding by FCT (2017 Call for SR&TD Project Grants). The goal of CBM-X is to develop biomolecular constructs for the precise modification of cellulose matrices with nanostructures and/or biomolecules, and for the anchoring of nanocellulose onto a range of materials. The project, which falls within the scientific area of Materials Engineering, is headed by Miguel Prazeres from BERG-iBB and involves a collaboration with the company NZYTech.

A new strategy to modify cellulose with the short antimicrobial hexapeptide MP196 (RWRWRW-NH2) is proposed by BERG and BSIRG researchers that uses fusions of Cys-terminated derivatives of MP196 and a carbohydrate binding module (CBM). CBM3-MP196-modified cellulose hydrogels displayed antibacterial activity that was significantly higher when compared with controls. This versatile concept offers a toolbox for the functionalization of different cellulose materials with a broad choice in peptides. the paper was published in Acta Biomaterialia. The work was funded by project CBM-X.

Lateral flow assays (LFA) are the dominant segment in the Point-Of-Care testing market. Analytical strips made of nitrocellulose (NC) are the heart of a LFA. However, NC is not necessarily the best matrix due to the inability to control the orientation of proteins, inconsistencies in flow rates, lot-to-lot variability, flammable nature, sensitivity to humidity, and an inherent brittleness. In a paper published in Biosensors, Miguel Prazeres from BERG-iBB with colleagues from the Indian Institute of Technology show that cellulose paper possesses the adequate characteristics to replace NC in a LFA for the quantitative, fluorescence-based detection of cardiac troponin I. It is further shown that the layering of carbon nanofibers favor the generation of more intense immunofluorescence signals. The results open up the possibility for companies to develop specialized cellulose strips for LFA. The work was funded by project CBM-X.

Ana Margarida Rosa will be defending her PhD thesis in Biotechnology and Biosciences on Wednesday the 29th january 2020 (10:30 H, amphitheater PA-3, Mathematics Building). During the last years, and under the supervision of Miguel Prazeres from BERG-iBB and Pedro Paulo from CQE-IST, Ana developed a cellulose-based system for the colorimetric detection of nucleic acids by exploring the recognition of biotin-labeled DNA hybrids by anti-biotin antibodies immobilized through ZZ-CBM chimeric proteins. These fusions combine carbohydrate-binding modules (CBM) with affinity to cellulose and double Z domains (ZZ) that bind to IgG antibodies. The title of the thesis is “DNA recognition system on bioactive paper using fusions of carbohydrate-binding modules and IgG-binding Z domains”.

Nucleic acid testing requires skilled personnel and expensive instrumentation and are thus difficult to implement in low income settings. In a paper published in the Biotechnology Journal, researchers from BERG-iBB describe a method for the detection of oligonucleotides that combines cellulose microparticles with biomolecular recognition. Cellulose microparticles are made bioactive by anchoring anti-biotin antibodies via ZZ-CBM fusions that combine a carbohydrate binding module with the ZZ fragment of protein A. Samples are prepared by incubating DNA probes immobilized on gold nanoparticles (AuNP) with biotin-labeled targets and then mixed with bioactive microparticles. The presence of un-labelled targets could also be probed by introducing a second, biotinylated DNA probe. The target:probe-AuNP hybrids are mixed with and captured by the microparticles, which change color from white to red. With this methodology, diverse analytical applications can be envisaged based on “reader-free” testing. The work was performed in the context of the project CBM-X.

A position is open at iBB to hire a doctorate researcher under the scope of the FCT-funded CBM-X project. The selected candidate (PhD holder) will work on the development (design, cloning, production, purification and testing) of bi-functional biomolecular constructs combining Carbohydrate Binding Modules (CBMs) with relevant biological partners (oligonucleotides, material binding peptides, avidin monomers and PDZ domains) that allow the modification of cellulose with nano materials and/or biomolecules.The work will be performed at BERG-iBB under the supervision of Prof. Miguel Prazeres. More information on the position and how to apply can be found here under the acronym CBM-X. The application deadline is February 5th, 2019.