Wirelessly Powered Electrical-Stimulation Based on Biodegradable 3D Piezoelectric Scaffolds Promotes the Spinal Cord Injury Repair.

An electroactive scaffold integrated with noninvasive in vivo electrical-stimulation (ES) capability shows great promise in the repair and regeneration of damaged tissues. Developing high-performance piezoelectric biomaterials which can simultaneously serve as both a biodegradable tissue scaffold and controllable electrical stimulator remains a great challenge. Herein, we constructed a biodegradable high-performance 3D piezoelectric scaffold with ultrasound (US)-driven wireless ES capability, and demonstrated its successful application for the repair of spinal cord injuries in a rat model. The 3D multichannel piezoelectric scaffold was prepared by electrospinning of poly(lactic acid) (PLA) nanofibers incorporated with biodegradable high-performance piezoelectric potassium sodium niobate (K0.5Na0.5NbO3, KNN) nanowires. With programmed US irradiation as a remote mechanical stimulus, the on-demand in vivo ES with an adjustable timeline, duration, and strength can be delivered by the 3D piezoelectric scaffold. Under proper US excitation, the 3D tissue scaffolds made of the piezoelectric composite nanofibers can accelerate the recovery of motor functions and enhance the repair of spinal cord injury. The immunohistofluorescence investigation indicated that the 3D piezoelectric scaffolds combined with the US-driven in vivo ES promoted neural stem cell differentiation and endogenous angiogenesis in the lesion. This work highlights the potential application of a biodegradable high-performance piezoelectric scaffold providing US-driven on-demand electrical cues for regenerative medicine.

Electrical Stimulation Induces Retinal Müller Cell Proliferation and Their Progenitor Cell Potential.

Non-invasive electrical stimulation (ES) is increasingly applied to improve vision in untreatable eye conditions, such as retinitis pigmentosa and age-related macular degeneration. Our previous study suggested that ES promoted retinal function and the proliferation of progenitor-like glial cells in mice with inherited photoreceptor degeneration; however, the underlying mechanism remains obscure. Müller cells (MCs) are thought to be dormant residential progenitor cells that possess a high potential for retinal neuron repair and functional plasticity. Here, we showed that ES with a ramp waveform of 20 Hz and 300 µA of current was effective at inducing mouse MC proliferation and enhancing their expression of progenitor cell markers, such as Crx (cone-rod homeobox) and Wnt7, as well as their production of trophic factors, including ciliary neurotrophic factor. RNA sequencing revealed that calcium signaling pathway activation was a key event, with a false discovery rate of 5.33 × 10-8 (p = 1.78 × 10-10) in ES-mediated gene profiling changes. Moreover, the calcium channel blocker, nifedipine, abolished the observed effects of ES on MC proliferation and progenitor cell gene induction, supporting a central role of ES-induced Ca2+ signaling in the MC changes. Our results suggest that low-current ES may present a convenient tool for manipulating MC behavior toward neuroregeneration and repair.

Electrical Stimulation as an Alternative Treatment in Gastroesophageal Reflux Disease - Clinical Study.

Background: Recently, there was described the possibility to increase the lower esophageal sphincter (LES) tone by means of implantable electrical stimulator. Although, this method has already been used in clinical practice, however, the optimal parameters of LES electrical stimulation are still unknown. Aims: The goals of this study were to get clinical data regarding the effects of different types of electrical stimulation on LES and to elaborate and test the prototype on laboratory animals. Material and Methods: In the Department of Surgery no 4, during 4 years (2015-2018), there has been achieved one clinical-experimental study of LES electrical stimulation. During the first stage, the electrical stimulation of the LES, using an external pulse generator, was assessed in 15 patients. These patients underwent an antireflux intervention, with an additional insertion of 2 temporary electrodes on the LES. During the second stage, there was created an experimental device which consisted of a re-insertable microstimulator using wireless energy transfer. During the third stage, it was tested in the experimental surgery center "Pius Branzeu", Timisoara, on laboratory animals (pigs). Results: Values of the LES resting pressure and integrated relaxation pressure (IRP) were significantly different during the prestimulation and poststimulation periods. Conclusions: There was successfully demonstrated the possibility to increase the LES tone. Modifications in the LES functionality and tone, during the electrical stimulation and in the period immediately after the stimulation, depend upon the pulse frequency and length. Also, the additional change of the Bluetooth transmitter antenna is necessary to offset the screening effect of the biological tissues.

Effect of power electrical stimulation in combination with task-oriented training on lower extremity motor function in stroke patients with foot drop / 中国脑血管病杂志

Objective Toinvestigatetheeffectofpowerelectricalstimulation(PES)incombination withtask-specifictrainingonlowerextremitymotorfunctioninstrokepatientswithfootdrop.Methods Fifty patients with poststroke foot drop were enrolled retrospectively. They were divided into either an experimental group or a control group (n=25 in each group). The control group received routine rehabilitation treatment. On this basis,the experimental group was given PES in combination with task-oriented training. Both groups of patients were trained 2 times a day,once for 40 minutes,5 days a week for 6 weeks. The ankle active range of motion,plantar flexor muscle tension,and tibialis anterior muscle strength were determined before and after treatment. The balance and lower extremity motor function of the patients were assessed by using Berg balance scale score,Fugl-Meyer lower extremity score,modified Barthel index,and Holden walk grading. At thesametime,thewalkingspeedandsteplengthbeforeandaftertreatmentwerecompared.Results Six weeks after treatment,the ankle activity,plantar flexors tension,and tibialis anterior muscle strength scores in patients of the experimental group were improved compared with before treatment,and each indicator was significant better than the control group (t=6. 261,-6. 163,and 2. 968,respectively;all P<0. 05). Berg balance scale,walking speed and step length scores were also improved as compared with before treatment, and each indicator was better than the control group (t=10. 733,9. 074,and 9. 013,respectively;all P<0.01). The lower limb motion scores,modified Barthel indexes,and Holden walk grading scores were improved compared with before treatment,and each indicator was significantly better than the control group (t=3.261,7.573,and4.010,respectively;allP<0.05).Conclusion Usingpowerelectricalstimulation in combination with task-oriented training may effectively improve the lower extremity motor function in stroke patients with foot drop.

Neurophysiological study of the acupuncture analgesia: Role of opioid receptor subtypes / 全日本鍼灸学会雑誌

It is well known that opioids cause analgesia and feeding elicitation by action in the either periaqueductal gray (PAG) or ventral tegmental area (VTA).<br>We have investigated that determination of opioids receptor subtype on the lateral hypothalamic area, as feeding center, electrical stimulation induced feeding (LHA-ESIF) followed microinjection of μ-(morphine), δ-(DADLE) and κ-(U50, 488H) receptor selective agonists and physiological saline into the VTA and PAG of chronic Wistar male rats, weighing between 350 and 480g. with stimulation fixed at a modulate level, 50Hz. time to eat three-45mg pellets within 45sec. were studied.<br>Dose of 10 (but not 1) nmol of three agonists microinjected into the VTA significantly (p<0.01) reduced time of LHA-ESIF, these agonists were almost equally effective at this dose. Naloxone(NLX) reversed the effects of each agonists. NLX was slightly more effective agonist morphine than against DADLE or U50, 488H. This results suggest that all three receptor subtype may be contributed to the VTA fascilitation of the LHA-ESIF, and NLX is a selective antagonist of μ-receptor.<br>In the microinjection of PAG, morphine (20, but not 2nmol) showed increasing LHA-ESIF, while both δ-and κ-agonists were each without effects. These results indicated that the PAG inhibition of LHA-ESIF is mediated solely by μ-receptor.<br>It is, thus suggests that opioids receptor subtypes on the PAG, as site of the acupuncture analgesia, might be contributed, neither δ-nor κ-receptors, through only via μ-receptor.