Biology subjects

Perez-Dominguez, S.

Publications and source records attributed to Perez-Dominguez, S..

2 recordsLinked to original sources

bioRxiv2023

Characterizing the viscoelastic properties of different fibroblasts in 2D and 3D collagen gels

We assessed cell mechanical properties in both 2D and 3D environments employing compliant type I collagen matrices. Firstly, collagen gels of varying stiffness were prepared using a photocrosslinker to increase gel stiffness. Using methacrylic anhydride and UV light, a 10-fold increase in apparent Youngs modulus with respect to the soft collagen gel was achieved (0.2 kPa to 2 kPa). In addition, cells were plated onto the different collagen gels and hard Petri dishes (as a super stiff substrate) and their mechanical properties were evaluated. An increase in apparent Youngs modulus was observed in Dupuytren fibroblasts behavior when increasing substrate stiffness, supporting its myofibroblast phenotype (3.8 kPa to 5.2 kPa from soft collagen gels to hard Petri dishes). Secondly, gels mechanics, in which fibroblasts were embedded, were evaluated over time to assess cells contraction properties. Gels apparent Youngs modulus increased over time regardless of fibroblasts type and cells presented dendritic protrusions. Rheological properties of both cells and gels were extracted using AFM sweep frequency scheme and power law structural damping model for data analysis. As a summary, we have found that fibroblasts contractile properties, related to myofibroblast differentiation and development are highly influenced on the mechanical properties of the surrounding environment, being stiffer environments those that favor the increase in fibroblast mechanical tension.

biophysics↗

bioRxiv2023

Reliable, standardized measurements for cell mechanical properties

Atomic force microscopy (AFM) has become indispensable for studying biological and medical samples. More than two decades of experiments have revealed that cancer cells are softer than healthy cells (for measured cells cultured on stiff substrates). The softness or, more precisely, the larger deformability of cancer cells, primarily independent of cancer types, could be used as a sensitive marker of pathological changes. The wide application of biomechanics in clinics would require designing instruments with specific calibration, data collection, and analysis procedures. For these reasons, such development is, at present, still very limited, hampering the clinical exploitation of mechanical measurements. Here, we propose a standardized operational protocol (SOP), developed within the EU ITN network Phys2BioMed, which allows the detection of the biomechanical properties of living cancer cells regardless of the nanoindentation instruments used (AFMs and other indenters) and the laboratory involved in the research. We standardized the cell cultures, AFM calibration, measurements, and data analysis. This effort resulted in a step-by-step SOP for cell cultures, instrument calibration, measurements, and data analysis, leading to the concordance of the results (Youngs modulus) measured among the six EU laboratories involved. Our results highlight the importance of the SOP in obtaining a reproducible mechanical characterization of cancer cells and paving the way toward exploiting biomechanics for diagnostic purposes in clinics.

biophysics↗