Oxygen vacancies enriched nickel cobalt based nanoflower cathodes: Mechanism and application of the enhanced energy storage

The rational design of oxygen vacancies and electronic microstructures of electrode materials for energy storage devices still remains a challenge. Herein, we synthesize nickel cobalt-based oxides nanoflower arrays assembled with nanowires grown on Ni foam via the hydrothermal process followed annealing process in air and argon atmospheres respectively. It is found that the annealing atmosphere has a vital influence on the oxygen vacancies and electronic microstructures of resulting NiCo_(2)O_(4) (NCO-Air) and CoNiO_(2) (NCO-Ar) products, which NCO-Ar has more oxygen vacancies and larger specific surface area of 163.48 m^(2)/g. The density functional theory calculation reveals that more oxygen vacancies can provide more electrons to adsorb –OH free anions resulting in superior electrochemical energy storage performance. Therefore, the assembled asymmetric supercapacitor of NCO-Ar//active carbon delivers an excellent energy density of 112.52 Wh/kg at a power density of 558.73 W/kg and the fabricated NCO-Ar//Zn battery presents the specific capacity of 180.20 mAh/g and energy density of 308.14 Wh/kg. The experimental measurement and theoretical calculation not only provide a facile strategy to construct flower-like mesoporous architectures with massive oxygen vacancies, but also demonstrate that NCO-Ar is an ideal electrode material for the next generation of energy storage devices.

A shear-thinning,ROS-scavenging hydrogel combined with dental pulp stem cells promotes spinal cord repair by inhibiting ferroptosis

Spinal cord injury(SCI)is a serious clinical disease.Due to the deformability and fragility of the spinal cord,overly rigid hydrogels cannot be used to treat SCI.Hence,we used TPA and Laponite to develop a hydrogel with shear-thinning ability.This hydrogel exhibits good deformation,allowing it to match the physical properties of the spinal cord;additionally,this hydrogel scavenges ROS well,allowing it to inhibit the lipid peroxidation caused by ferroptosis.According to the in vivo studies,the TPA@Laponite hydrogel could synergistically inhibit ferroptosis by improving vascular function and regulating iron metabolism.In addition,dental pulp stem cells(DPSCs)were introduced into the TPA@Laponite hydrogel to regulate the ratios of excitatory and inhibitory synapses.It was shown that this combination biomaterial effectively reduced muscle spasms and promoted recovery from SCI.

Hypoxia response element-directed expression of bFGF in dental pulp stem cells improve the hypoxic environment by targeting pericytes in SCI rats

Cell-based transplantation strategies possess great potential for spinal cord injury(SCI)repair.Basic fibroblast growth factor(bFGF)has been reported to have multiple neuro-promoting effects on developing and adult nervous system of mammals and considered a promising therapy for nerve injury following SCI.Human dental pulp stem cells(DPSCs)are abundant stem cells with low immune rejection,which can be considered for cell replacement therapy.The purpose of this study was to investigate the roles of DPSCs which express bFGF under the regulation of five hypoxia-responsive elements(5HRE)using an adeno-associated virus(AAV-5HRE-bFGF-DPSCs)in SCI repairing model.In this study,DPSCs were revealed to differentiate into CD13^(+)pericytes and up-regulate N-cadherin expression to promote the re-attachment of CD13^(+)pericytes to vascular endothelial cells.The re-attachment of CD13^(+)pericytes to vascular endothelial cells subsequently increased the flow rate of blood in microvessels via the contraction of protuberance.As a result,increased numbers of red blood cells carried more oxygen to the damaged area and the local hypoxia microenvironment in SCI was improved.Thus,this study represents a step forward towards the potential use of AAV-5HRE-bFGF-DPSCs in SCI treatment in clinic.

The marriage of sealant agent between structure transformable silk fibroin and traditional Chinese medicine for faster skin repair

Fast skin repair is critical for less infection, less pain and high quality of life, which is still limited with undesirable rehabilitation speed and side effects. Currently, laser-activated silk sealant agent without suture and gauze has been demonstrated promising for fast skin repair taking advantage of its structural transformation after heating. Nevertheless, more efficient healing effects and less side effects of laseractivated silk sealant agent remains challenging due to absence of suitable photo-thermal materials and robust/biomimetic protein materials. In this work, the marriage between silk protein and Rehmanniae radix preparata(a kind of the traditional Chinese herb) has been demonstrated as a novel and effective way to achieve an excellent healing effect for skin repair. The non-toxicity, high photothermal conversion efficiency and healing mechanism are systematically studied and proved. This new methodology might shed a new light for combining dark traditional Chinese medicine and silk fibroin for advanced wound healing technology.