Biomedical Engineering Reference
In-Depth Information
Donor-to-Donor Variability
The genetic variability in the human population is substantial. Therefore, outcome from
cell isolations and tissue engineering approaches can vary significantly between donors.
Even if the cell growth process, the production of materials, and the formulation of medium
are essentially identical, a large variation in outcomes among donors can still result. This
variability is due to intrinsic biological factors. Some regularization in performance can be
achieved by using a full complement of accessory cells. Although interdonor variability is
considerable, the behavior of the same tissue source is internally consistent. An example
is shown in Figure 6.34, where the relative uptake rates of growth factors are shown for a
number of donor samples. The uptake rates of growth factors can be highly correlated
within many donor samples. The quantitative nature of the correlation changes from donor
to donor, making it difficult to develop a correlation that would represent a large donor
population.
80000
60000
40000
20000
0
0
200
Epo Consumed (mU)
400
600
800
(a)
45000
30000
15000
0
0
2500
IL-3 Consumed (pg)
5000
7500
10000
(b)
FIGURE 6.34
The uptake of growth factors—that is, stem cell factor (SCF) and erythropoietin (Epo)—is highly
correlated in cultures of human bone marrow. The correlation is strong for a single tissue sample. The slopes of the
curves vary significantly among donors.
From [8].
