|M.Sc Student||Zeidman Kalman Tal|
|Subject||Development of Nanostructured Porous Silicon/Hydrogel|
Hybrids: Towards Cell-based Biosensors
|Department||Department of Biotechnology and Food Engineering||Supervisor||Professor Ester H. Segal|
|Full Thesis text|
In recent years porous Si (PSi) has emerged as a promising platform for both molecular and cell-based biosensing applications. PSi is typically synthesized by anodic electrochemical etching of a single-crystal Si wafer. The resulting nanomaterials are characterized by tunable structural properties combined with unique optical properties. In order to utilize PSi nanostructures for cell-based biosensing the stabilization of the Si scaffold in aqueous media and its compatibility with mammalian cells and tissues must be confirmed. In this work we introduce a new class of hybrid materials, based on oxidized PSi (PSiO2) hosts and hydrogels, which maintain both long-term cell viability and surface stability. This work is focused on the design, fabrication and characterization of these hybrids as potential surfaces for optical cell-based biosensors.
Two types of hydrogels were studied. The first is a novel biosynthetic protein-polymer conjugate comprised of polyethylene glycol (PEG) and fibrin. The second is a positively charged synthetic copolymer based on 2-hydroxyethylester (HEA) and 2-methacrylaloxy trimethyl ammonium chloride (MEATAC). Both hydrogels were synthesized in situ within nanostructured porous SiO2 films i.e., Fabry Perot thin films and one-dimensional photonic crystals. The attachment and long-term viability of three types of human cancer cell lines (glioma U87, breast cancer MDA-MB-231, and cervical cancer HeLa) onto the hybrid surfaces and the neat PSiO2 substrates was investigated. The resulting hybrids combine the unique optical properties of the porous SiO2 and the biocompatibile hydrogel layer, which stimuli and maintain cell adhesion and viability. Enhanced attachment was observed for the PSiO2/poly(HEA-co-MEATAC) hybrids irrespective to cell type. The results of the study demonstrate the potential of PSiO2/hydrogel hybrids as platforms for optical cell-based biosensing and drug screening applications.