This preview shows pages 1–2. Sign up to view the full content.
2.79J/3.96J/BEH.441/HST522J
Biomaterials  Tissue Interactions
Homework #7
1. A set of force vs time data has been obtained using the cell force monitor (Fig. 1). The
system consists of fibroblasts supported on an analog of the extracellular matrix in
culture medium. The data have been fitted well at each level of the cell density using the
following equation:
f (t) = f
∞
[1exp(kt)]
where f
∞
and k are constants.
Derive df(t)/dt and calculate its limiting values at t = 0 and t =
∞
. Describe an
analytical procedure for measuring k.
2. Assume for the moment that the cells in this system act noncooperatively, i.e.,
independently of each other. Derive a mathematical relation between the limiting value of
df(t)/dt at t = 0, i.e., (df/dt)
0
, and the cell density D.
3. Tests for cellcooperativity.
(A) Assume that a problem has developed in your laboratory with the cell culture
medium. As a result, the cells have started to behave irreproducibly after staying 4 h in
the medium. You are limited to data obtained before t = 4 h. Can data obtained at t <4 h
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview. Sign up
to
access the rest of the document.
 Spring '03
 RogerD.Kamm

Click to edit the document details