(F-215) Characterization of viscoelastic properties of human melanoma tissue using viscoelastic models

Introduction:: Melanoma is the most lethal and aggressive form of skin cancer, which is responsible for the majority of skin cancer-related deaths. While it is well-established that the mechanical properties of tumorous tissue undergo significant changes, there is a severe lack of data on in vivo characterization of the mechanical properties of melanoma tissue. Furthermore, the viscoelastic or viscous properties of melanoma tissue are rarely reported compared to its stiffness or elastic properties.


Materials and Methods:: In this study, we measured and quantified the viscoelastic properties of human melanoma tissues using a stress relaxation test and an indentation-based mechanical analyzer. The study included melanoma tissues excised from eight patients with varying ages (57–95), genders (male and female), races (White and Asian), and affected sites (nose, arm, shoulder, and chest). The viscoelastic properties were approximated using the Prony series for 5-element generalized Maxwell and 5-element generalized Kelvin-Voigt models. In addition, we compared viscoelastic properties using interconversion formulas for the two models.


Results, Conclusions, and Discussions:: The findings of our study revealed that the elastic property (shear modulus) of melanoma tissue was notably higher than that of normal tissue, while the viscous property (relaxation time) was considerably lower. Furthermore, tissue thickness played a significant role in the viscoelastic properties. Specifically, we found that the stiffness increased with decreasing thickness, which may be attributed to the amount of the adipose layer. However, we observed that the immersion condition did not affect the viscoelastic properties, as we did not detect any significant differences when the samples were immersed in either air or liquid. Finally, we successfully validated and confirmed the equivalence between generalized Maxwell and generalized Kelvin-Voigt models using the Prony series. These results provide novel insights into the significance of the viscous and elastic properties of melanoma cell mechanics, which may play a role in the progression and state of the disease beyond current knowledge.


Acknowledgements (Optional): : This study was supported by the National Institute on Aging (NIA) of the National Institutes of Health (NIH) under award number K25AG070286.

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