Journal: NPJ Regenerative Medicine

Article Title: Capacitive interdigitated system of high osteoinductive/conductive performance for personalized acting-sensing implants

doi: 10.1038/s41536-021-00184-6

Figure Lengend Snippet: The stimulation apparatus comprises a control station ( a ) coupled to an I/O cardboard ( b ) for signal conditioning, and a signal generator ( c ) that ensures the generation of high-frequency (HF) excitations. The control station runs a real-time application that configures the excitation amplitude, daily exposure, and total stimulation duration. HF voltage excitations (60 kHz) have a defined waveform ( d ). Maximum electric field (EF) stimuli [0.7 vs 0.3 V/mm] are delivered for high- (60 kHz) or low-frequency (LF; 14 Hz) excitations ( e ), as predicted by a finite element computational model implemented using COMSOL Multiphysics (v. 5.3). The 100-μm-thick cosurface interdigitated electrodes ( f ) have a 35 mm diameter architecture (measures in mm in g ). The electrode delivers frequency- and region-dependent EF stimuli to cells, with maximum EFs imposed over positively-charged electrodes and minimum EFs over the grounded electrodes. Stimuli distribution and strength along the xy -plane was determined under high- ( h ) and low-( i ) frequency stimulation. In vitro stimulation was performed inside an instrumented CO 2 incubator ( j ) connected to the stimulation apparatus, and cultures were grown in 35 mm culture dishes. The incubator contains both the control culture dishes ( k ) and the dishes receiving electrical stimulation, which are placed above each stimulator ( l ). These thin 35 mm electrodes are planned for assembly into bioelectronic active implants ( m ) to improve osseointegration around the bone–implant interface.

Article Snippet: The AC/DC module of COMSOL Multiphysics (v. 5.3, COMSOL) was used to develop all the computational models and to simulate the electrical stimuli delivered by the interdigitated stimulator.

Techniques: Control, In Vitro