Hybrid nanogenerator based closed-loop self-powered low-level vagus nerve stimulation system for atrial fibrillation treatment

Atrial fibrillation is an “invisible killer” of human health. It often induces high-risk diseases, such as myocardial infarction, stroke, and heart failure. Fortunately, atrial fibrillation can be diagnosed and treated early. Low-level vagus nerve stimulation(LL-VNS) is a promising therapeutic method for atrial fibrillation. However, some fundamental challenges still need to be overcome in terms of flexibility,miniaturization, and long-term service of bioelectric stimulation devices. Here, we designed a closedloop self-powered LL-VNS system that can monitor the patient’s pulse wave status in real time and conduct stimulation impulses automatically during the development of atrial fibrillation. The implant is a hybrid nanogenerator(H-NG), which is flexible, light weight, and simple, even without electronic circuits,components, and batteries. The maximum output of the H-NG was 14.8 V and 17.8 μA(peak to peak). In the in vivo effect verification study, the atrial fibrillation duration significantly decreased by 90% after LLVNS therapy, and myocardial fibrosis and atrial connexin levels were effectively improved. Notably, the anti-inflammatory effect triggered by mediating the NF-κB and AP-1 pathways in our therapeutic system is observed. Overall, this implantable bioelectronic device is expected to be used for self-powerability,intelligentization, portability for management, and therapy of chronic diseases.

Green functional carbon dots derived from herbal medicine ameliorate blood–brain barrier permeability following traumatic brain injury

To repair the blood–brain barrier(BBB)after traumatic brain injury(TBI)remains a multidisciplinary challenge.No first-line drugs are available.Here,we reported a novel and non-toxic functional negative-charged carbon dots(CDs)generated from green Semen pruni persicae and Carthamus tinctorius L.(TH-CDs)through a hydrothermal synthesis without any organic solvent.The surface of TH-CDs retained part functional groups of active pharmacophores from both drugs.TH-CDs could improve the neurological function,brain edema,neuronal damage,and the BBB permeability by tail vein injection of mice models without systemic toxicity.Furthermore,higher expression of tight junction proteins claudin 5 and ZO-1 was observed after TH-CDs administration,which may be due to the electrostatic interaction between TH-CDs and claudin 5.Our study highlights an inexpensive,green,non-toxic,and intravenous functional TH-CD,which represents a potential TBI treatment strategy.