Conductive Nanocomposite Hydrogel Based On Dynamic Borate Ester Bonds For Medical Sensing And Wound Therapy

Epidermal sensors based on conductive hydrogels that can real-time detect human physiological activity signals are expected to change people’s lifestyle,because of the potential applications in artificial skin,human healthcare monitoring,and smart medicine.However,the reported epidermal sensors assembled from conductive hydrogel ordinarily exhibited poor mechanical,electrical,and sensing performance,as well as suffered damage under deformation.To date,flexible epidermic sensors from conductive hydrogel have been well developed for personal health monitoring,but lack the effective treatment ability to achieve the integration of diagnosis and therapy.As a result,a flexible healable epidermic sensor is assembled from the easiy prepared antibacterial MXene hydrogel with promoted wound repair for wearable human-machine interfacing and wound therapy.The details of the work are as follows.1.We prepared MXene composite hydrogels by introducing Ag NPs/MXene nanosheet networks into the hydrogel networks of phenylboronic acid grafted sodium alginate(Alg-PBA)and guar gum(GG).Due to the supramolecular interaction among Ag NPs/MXene nanosheets,GG,and Alg-PBA,and the dynamic crosslinking between the phenylboronic acid groups of Alg-PBA and the hydroxyl groups of GG,the MXene composite hydrogels displayed excellent self-healing ability and were able to restore the electrical signal transmission of the broken circuit.Meanwhile,the prepared MXene composite hydrogels exhibited enhanced mechanical,electrical,and sensing properties,which could be assembled as high-performance healable epidermal sensors to fast monitor large human movements and teeny electrophysiological signals(the ECG and EMG signals).The signals of wrist and finger bending detected by MXene composite hydrogel-based sensor could be used to facilitate post-operative reconstruction of joint injuries.The signal of pulse clearly showed the pulse rate(80 bpm)and the value of radial augmentation index of the radial artery(AI_r=0.5),which is significant for the diagnosis of vascular aging and arterial stiffness.The high-quality ECG signals show five distinguishable characteristic peaks(P,Q,R,S,T),which can provide important diagnostic information for various heart-related diseases,such as arrhythmia,coronary heart disease or congestive heart disease heart failure,etc.Meanwhile,the EMG signals from muscle contractions with different gripping strengths(5 kg,10 kg,20 kg)could be used to facilitate the rehabilitation training of patients with muscle damage.Moreover,in combination with a wireless transmitter,the MXene composite hydrogel-based sensor could be employed to wirelessly sense the repeated punching of the volunteer-controlled robot for wearable human-machine interfacing.2.Moreover,the as-prepared hydrogel displayed reliable injectability,good cytocompatibility,and excellent blood compatibility,which can be directly injected onto the wound sites.Meanwhile,the MXene composite hydrogel with the similar modulus as human skin could completely covered the irregularly shaped wound to protecting it from further infection.The hydrogel exhibited robust antibacterial capabilities and could effectively kill S.aureus(77.78%)and E.coli(85.82%).Furthermore,the MXene composite hydrogel could be employed for wound therapy and nearly 98.16%of the wound area could be repaired by using the MXene composite hydrogel dressing on the 12th day,exhibiting much better wound healing efficiency than that of the commercial dressing(≈80.50%)and the hydrogel dressing without Ag NPs/MXene(≈83.83%).These results demonstrate the great potential of the MXene hydrogel in human healthcare and smart medical treatment.