Photodamage of dental pulpa stem cells during 700 fs laser exposure
February 14, 2018
Material and methods
Human stem cells from the dental pulp of adults (given by S. Gronthos, NIH, Bethesda, USA) were cultivated in α-modified Eagle’s Medium (MEM) by Gibco BRL Life Technologies (Paisley, Scotland) while adding 20 % FCS, 2 mM L-glutamine, 100 μM L-ascorbate-2-phosphate, 100 μ Penicillin and 100 μg/ml Streptomycin at 5 % CO2 and 37 °C in 25 ml and 75 ml cell culture flasks (Greiner, Frickenhausen, Germany). The cells were treated for experiments and cultivation with 0.25 % trypsin, 5 mM glucose, 0.05% EDTA in PBS for 5 minutes at 37 °C. After having been thus detached from the base of the culture flasks, the cells were incubated in cell chambers (MiniCeM, JenLab GmbH, Jena, Germany) for laser microscopy.
Comparative studies were conducted on Chinese hamster ovary (CHO) cells, which are available in many international laboratories as reference cells. The CHO cells were incubated in Dulbeccos HAM-F12 Medium (Gibco BRL) with 10 % FCS, L-glutamine and an antibiotic mix of Penicillin, Streptomycin and Amphotericin B at 5 % CO2 and 37 °C. Trypsinisation corresponded to that of the stem cells.