Beschreibung:
<jats:p>Stem cell-like keratinocytes are responsible for the high regenerative potential of the skin. For clinical applications using keratinocytes in artificial skin constructs, it is suitable to work with serum-free medium under defined conditions. This is also true for the preceding expansion of the stem cell-like keratinocyte population. Therefore, we analyzed the effect of a serum-free medium on the population distribution in comparison to an established serum-containing standard medium for keratinocyte culture. We quantified the freshly isolated as well as cultured primary human keratinocytes by their expression of the β<sub>1</sub> integrin (CD29) in combination with the expression of the α<sub>6</sub> integrin (CD49f) and the transferrin receptor (CD71) by flow cytometric methods. We were able to show that cultivation with serum-free medium induces a switch of the cell population to higher expression of the β<sub>1</sub> integrin. In addition, the proportion of the α<sub>6</sub><sup>bri</sup>/ CD71<sup>dim</sup>-expressing keratinocyte cell population was enhanced about 35.4 ± 6.56% after cultivation with serum-free medium. Culture in serum-containing medium increased this proportion of the keratinocyte cell population only about 17.3 ± 8.06%, when compared to the α<sub>6</sub><sup>bri</sup>/ CD71<sup>dim</sup>-expressing keratinocyte cell population measured directly after isolation. Our data show that the applied culture conditions already have an enormous impact on the development of a stem cell-like phenotype of keratinocytes. This work demonstrates that the serum-free medium significantly increases the proportion of β<sub>1</sub><sup>bri</sup>/α<sub>6</sub><sup>bri</sup>/CD71<sup>dim</sup>-expressing keratinocytes. In conclusion, these findings implicate new applications in keratinocyte stem cell research and regenerative medicine.</jats:p>