Surface Treatment of Polymeric Materials Controlling the Adhesion of Biomolecules

in Journal of Functional Biomaterials (2012), 3

This review describes different strategies of surface elaboration for a better control of biomolecule adsorption. After a brief description of the fundamental interactions between surfaces and ... [more ▼]

This review describes different strategies of surface elaboration for a better control of biomolecule adsorption. After a brief description of the fundamental interactions between surfaces and biomolecules, various routes of surface elaboration are presented dealing with the attachment of functional groups mostly thanks to plasma techniques, with the grafting to and from methods, and with the adsorption of surfactants. The grafting of stimuli-responsive polymers is also pointed out. Then, the discussion is focused on the protein adsorption phenomena showing how their interactions with solid surfaces are complex. The adsorption mechanism is proved to be dependent on the solid surface physicochemical properties as well as on the surface and conformation properties of the proteins. Different behaviors are also reported for complex multiple protein solutions. [less ▲]

Increasing the Detection Limit of the Parkinson Disorder through a Specific Surface Chemistry Applied onto Inner Surface of the Titration Well

in Journal of Functional Biomaterials (2012), 2

The main objective of this paper was to illustrate the enhancement of the sensitivity of ELISA titration for neurodegenerative proteins by reducing nonspecific adsorptions that could lead to false ... [more ▼]

The main objective of this paper was to illustrate the enhancement of the sensitivity of ELISA titration for neurodegenerative proteins by reducing nonspecific adsorptions that could lead to false positives. This goal was obtained thanks to the association of plasma and wet chemistries applied to the inner surface of the titration well. The polypropylene surface was plasma-activated and then, dip-coated with different amphiphilic molecules. These molecules have more or less long hydrocarbon chains and may be charged. The modified surfaces were characterized in terms of hydrophilic—phobic character, surface chemical groups and topography. Finally, the coated wells were tested during the ELISA titration of the specific antibody capture of the α-synuclein protein. The highest sensitivity is obtained with polar (Θ = 35°), negatively charged and smooth inner surface. [less ▲]

Risk of Alzheimer’s Disease biological misdiagnosis linked to cerebrospinal collection tubes

in Journal of Alzheimer's Disease [=JAD] (2012), 31((1)), 13-20

Tau proteins and amyloid-β (Aβ) peptides are the current recognized cerebrospinal fluid (CSF) biomarkers used as an aid in the diagnosis of Alzheimer's disease (AD). However, there is no consensus on ... [more ▼]

Tau proteins and amyloid-β (Aβ) peptides are the current recognized cerebrospinal fluid (CSF) biomarkers used as an aid in the diagnosis of Alzheimer's disease (AD). However, there is no consensus on their clinical use due to non-qualified cut-off values, probably related to the observed high pre-analytical and analytical variability. Standardized pre-analytical protocols have therefore been proposed. Importantly, these recommend the use of polypropylene collection/sampling tubes while, to date, no broad comparison of these types of tubes has been conducted. In this study, we first compared, as part of a real clinical workflow, the impact of four different collection tubes on the CSF concentration of Aβ peptides (Aβ42, Aβ40) and total (hTau) and phosphorylated (P-Tau181P) tau proteins measured using routine ELISA kits. We then extended this study to 11 polypropylene tubes used by different clinical laboratories, and investigated their plastic polymer composition using differential scanning calorimetry and Fourier Transformed Infrared spectroscopy. Significant concentration variations linked solely to the use of different types of tubes were observed. This was particularly marked for Aβ peptides, with >50% disparity occurring in less than five minutes. Polymer composition analysis revealed that most polypropylene tubes were in fact copolymers with at least polyethylene. There was no clear correlation between tube composition and pre-analytical behavior. Our results show that the use of polypropylene tubes does not guarantee satisfactory pre-analytical behavior. They also point to collection/sampling tubes being a major pre-analytical source of variability that could impact the significance of AD biological diagnosis. [less ▲]

Pre-Mortem Diagnostic Screening for Transmissible Spongiform Encephalopathies by Proteomic Approaches

Book published by Nova Publishers (2012)

Non-Adhesive Behavior of New Nanostructured PNIPAM Surfaces Towards Specific Neurodegenerative Proteins: Application to Storage and Titration of Tau Proteins

in Macromolecular Bioscience (2012)

Are the interactions between neurodegenerative proteins and polymeric surfaces related to the hydrophilic and hydrophobic balance ?

in Macromolecular Bioscience (2012), In press

In press

Study of the Adhesion of Neurodegenerative Proteins on Plasma-Modified and Coated Polypropylene Surfaces.

in Journal of Biomaterials Science. Polymer Edition (2011)

Alzheimer’s diseases: towards biomarkers for an early diagnosis

Book published by InTech (2011)

Ku proteins interact with activator protein-2 transcription factors and contribute to ERBB2 overexpression in breast cancer cell lines.

in Breast Cancer Research [=BCR] (2009), 11(6),

INTRODUCTION: Activator protein-2 (AP-2) alpha and AP-2 gamma transcription factors contribute to ERBB2 gene overexpression in breast cancer. In order to understand the mechanism by which the ERBB2 gene ... [more ▼]

INTRODUCTION: Activator protein-2 (AP-2) alpha and AP-2 gamma transcription factors contribute to ERBB2 gene overexpression in breast cancer. In order to understand the mechanism by which the ERBB2 gene is overexpressed we searched for novel AP-2 interacting factors that contribute to its activity. METHODS: Ku proteins were identified as AP-2 alpha interacting proteins by glutathione serine transferase (GST)-pull down followed by mass spectrometry. Transfection of the cells with siRNA, expression vectors and reporter vectors as well as chromatin immunoprecipitation (ChIP) assay were used to ascertain the implication of Ku proteins on ERBB2 expression. RESULTS: Nuclear proteins from BT-474 cells overexpressing AP-2 alpha and AP-2 gamma were incubated with GST-AP2 or GST coated beads. Among the proteins retained specifically on GST-AP2 coated beads Ku70 and Ku80 proteins were identified by mass spectrometry. The contribution of Ku proteins to ERBB2 gene expression in BT-474 and SKBR3 cell lines was investigated by downregulating Ku proteins through the use of specific siRNAs. Depletion of Ku proteins led to downregulation of ERBB2 mRNA and protein levels. Furthermore, reduction of Ku80 in HCT116 cell line decreased the AP-2 alpha activity on a reporter vector containing an AP-2 binding site linked to the ERBB2 core promoter, and transfection of Ku80 increased the activity of AP-2 alpha on this promoter. Ku siRNAs also inhibited the activity of this reporter vector in BT-474 and SKBR3 cell lines and the activity of the ERBB2 promoter was further reduced by combining Ku siRNAs with AP-2 alpha and AP-2 gamma siRNAs. ChIP experiments with chromatin extracted from wild type or AP-2 alpha and AP-2 gamma or Ku70 siRNA transfected BT-474 cells demonstrated Ku70 recruitment to the ERBB2 proximal promoter in association with AP-2 alpha and AP-2 gamma. Moreover, Ku70 siRNA like AP-2 siRNAs, greatly reduced PolII recruitment to the ERBB2 proximal promoter. CONCLUSIONS: Ku proteins in interaction with AP-2 (alpha and gamma) contribute to increased ERBB2 mRNA and protein levels in breast cancer cells. [less ▲]

A decade of improvements in quantification of gene expression and internal standard selection.

in Biotechnology Advances (2009)

Major improvements have been made in mRNA quantification and internal standard selection over the last decade. Our aim in this paper is to present the main developments that are of interest for practical ... [more ▼]

Major improvements have been made in mRNA quantification and internal standard selection over the last decade. Our aim in this paper is to present the main developments that are of interest for practical laboratory work, contrasting the situation as it is now with the one of ten years ago, and presenting some excellent examples of what can be done today. Specifically, we will mainly discuss Real-Time RT-PCR major improvements that have been performed in the following areas: the most commonly used quantification techniques, the mathematical and software tools created to help researchers in their work on internal standard selection, the availability of detection chemistries and technical information and of commercial tools and services. In addition to mRNA quantification, we will also discuss some aspects of non-coding RNA and protein quantification. In addition to technical improvements, the development of international cooperation and the creation of technical databases are likely to represent a major tool for the future in the standardization of gene expression quantification. [less ▲]