Nada Abroug (Rostock, DE), Janine Waletzko-Hellwig (Rostock, DE), Lisa Schöbel (Erlangen, DE), Dr. Rainer Detsch (Erlangen, DE), Prof. Dr. Aldo R. Boccaccini (Erlangen, DE), PD Dr. Anika Jonitz-Heincke (Rostock, DE), Prof. Dr. Rainer Bader (Rostock, DE), Prof. Dr. Hermann Seitz (Rostock, DE)
Abstract text (incl. figure legends and references)
Introduction Hydrogels have inferior load-bearing capabilities than cartilage tissue which allow them to provide a temporal 3D-environment for the seeded cells. Mechanical stability is necessary for the balance between extracellular-matrix growth, ensured by the cells, and scaffold"s degradation. Furthermore, electrical stimulation is a potentially favourable in tissue engineering applications, notably in cartilage regeneration and the crucial preservation of the seeded-cells' chondrogenic phenotype.
Objectives We opted to evaluate the impact of certain electrical stimulation parameters on the mechanical integrity of cell-seeded hydrogels.
Materials and Methods Hydrogels were prepared as previously described[1]. Chondrocytes derived from articular cartilage of New-Zealand White rabbits were seeded on the hydrogels. Direct in-vitro electrical stimulation was applied using an established setup[2] with 0.7 Veff at frequencies of 1 kHz and 60 kHz for 7 and 14 days each. Constant strain-rate compressive tests up to 15% strain and at 100µm/s were performed post- and pre-stimulation in order to assess the evolution of the mechanical response.
Results Compared to control group, specimens stimulated at 1kHz for 7 days showed invariant compressive strength and hysteresis, while the ones that underwent 14 days of stimulation were less performant. Contrarily, the 60kHz groups present with an increase in both compressive strength and hysteresis for both the 7- and 14-day span of stimulation.
Conclusion The hydrogels displayed mechanical stability and even improvement during the cultivation and stimulation periods. An increase in hysteresis and compressive strength might indicate an improved viscous response due to aggrecans and collagen production. Further experiments are ongoing in order to characterise hydrogels' mechanical properties and their role in assessing stimulation parameters.
[1] DOI 10.1088/1758-5090/ab98e4
[2] DOI 10.3389/fphys.2022.965181
Funded by DFG