title: A Highly Responsive System for On-line in vitro Assessment of Tissue Growth within MicroPorous Polymer Scaffolds.
abstract: We have proposed a highly responsive system for the on-line in vitro assessment of tissue growth within microporous polymer scaffolds that obviates any compromise of sample integrity. The system's function is based on the sample's loss factor: the imaginary part of the complex permittivity. Reflection measurements were performed using an open-ended coaxial probe and impedance analyzer; they were then related to the sample's complex permittivity by a quasi-static model of the probe's aperture admittance. Measurements of saline solutions showed that the real part of permittivity was corrupted by apparent polarization effects. Consequently, we developed a simplified formulation of the imaginary part of the Hanai-Wagner effective medium approximation to eliminate its dependence on the real part of complex permittivity measurement. This formulation allows the sample's cell concentration to be determined. The variation of a sample's cell concentration over time was used as a measure of tissue growth. Measurements in the frequency range of 10-200 MHz were performed on micro-porous polymer scaffolds seeded with progressively greater number of cells. Results demonstrated that the system detected concentration differences between cell-seeded scaffolds.
authors.affiliation: McGill University, Montreal, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Dziong
authors.forename: R E
authors.initials: RE
authors.lastname: Kearney
authors.forename: M
authors.initials: M
authors.lastname: Tabrizian
authors.forename: P
authors.initials: P
authors.lastname: Bagnaninchi