Extended Data Fig. 3: S-NeuroString for sensing and stimulation in the GI tracts of anesthetized pigs.
From: High-density soft bioelectronic fibres for multimodal sensing and stimulation
a, Comparison of our GI S-NeuroString with existing manometry probes in terms of diameter and sensor density (Extended Data Table 2). b, Schematic and photographic illustrations showing an S-NeuroString inserted into the small intestine of an anesthetized pig to monitor and modulate GI functions. Parts of the schematic were created using BioRender.com. c, Recording of natural motility in the small intestine using a S-NeuroString with 8 pressure sensors (S1-S8). All traces are normalized and shifted for clarity (see methods). d, Schematic illustration of the 2D design used to roll-up into a bifunctional S-NeuroString used for simultaneous motility sensing (S1-S5) and stimulation (SE1-SE5). e, A photograph showing the bifunctional S-NeuroString obtained from the 2D design shown in (d). f, Pressure sensor output in response to stimulation at 2 and 4 V. g, Summary of the response obtained under stimulation at different voltages (n = 7 stimulation experiments, 2 S-NeuroStrings, 2 pigs). Bars represent the mean, with error bars indicating SD. The results in (f) and (g) were obtained from sensors and stimulation electrodes that are located at the same point. h, Schematic illustration showing the use of distributed stimulation electrodes to induce programmable contraction events over the length of the intestinal segments. i, Demonstration of the programmable stimulation and induced contractions. Stimulation of the pig intestine at different locations generates progressive contractions, as indicated by the propagation of the pressure wave using the arrows. Distributed pressure sensors provide feedback about the location and progression of contractions. j, Schematic illustration showing the use of SSRI injection (0.5 ml of 10 µM) to induce serotonin release inside the intestine. k, Drug-induced luminal serotonin concentration change using an SSRI solution and PBS as control (n = 5 experiments, 3 S-NeuroStrings, 3 pigs). Short horizontal lines represent the mean. Each point is the average of 5 electrochemical sensors as shown in Supplementary Fig. 23. Paired, two-tailed Student’s t-test. l, Electrochemical sensing of SSRI-induced serotonin using cycling voltammetry. The red dotted line boxed region indicates the electrochemical oxidation of serotonin.
