The use of the interference microscopy to study structural characteristics of cultured dermal fibroblasts

Rationale: The use of electron, nuclear power and confocal microscopy for the screening of biologically active compounds, medical products and express diagnostics of some diseases at the cell level is associated with laborand time-consuming sample preparation, which cannot exclude potential measurement errors and artifacts. The modulation interference microscopy does not have these disadvantages; it allows for non-invasive studies of cell structures, imaging with nanometer resolution and analysis of the optical properties of an object.

Aim: To assess the potential of the interference microscopy in the evaluation of morphofunctional characteristics of in vitro mitomycin conditioned cultured cell nuclei (dermal fibroblasts taken as a model).

Materials and methods: Native culture of human dermal fibroblasts of the 6th passage, grown on glass with mirror coating in the cell culture laboratory of the Institute of Experimental Medicine and Biotechnology of Samara State Medical University (Russia), was examined with a modulation interference microscope MIM-340 (JSC PA UOMZ, Russia). Changes over time in the structural characteristics of dermal fbroblast nuclei conditioned with mitomycin were evaluated. The control group included fibroblasts cultured in the same conditions on glass with mirror coating without mitomycin. Imaging with MIM-340 was done at three hours, one and four days after adding the cytostatic. The control group was assessed at the same time points.

Results: We have shown that the cell culture grown on dielectric glasses does not differ in its morphofunctional characteristics from the culture grown on culture plastics. This proves the possibility to study the adhesive native culture using interference microscopy. We have found that the cells respond to a single mitomycin 0.04% exposure with a change to a globular shape and a sharp increase in the nuclear phase thickness (217.8 vs. 142.18 nm in the control group, p ≤ 0.05). Thereafter, the morphofunctional characteristics of the cells are restored, which is confirmed by the changes over time in the culture density, cell shape and size, and the phase thickness of the nucleus.

Conclusion: The results obtained make it possible to recommend the method of modulation interference microscopy for evaluation of toxicity and biocompatibility of drugs, medical products and physical factors for diagnosis and treatment.