Ce Zhu,Miaomiao He,Juehan Wang,Yong Huang,Wei Deng,Limin Liu,Ganjun Feng,Li Zhang,Yueming Song
Photothermal therapy (PTT) is a desirable way to attain on-demand hyperthermia owing to the heat generated by photothermal materials absorbing near-infrared) light. The mild heat (42 ± 0.5 °C) can not only accelerate bone tissue regeneration but also promote the release of bioactive ions from biomaterials. Based on this one-stone-two-birds strategy, a 3D printed PEEK-graphene composite scaffold (PG) with hydroxyapatite (HA) coating (PGH) for photothermally remote control of bone regeneration was well designed in this study. The results showed that the HA coating on PGH could release Ca 2+ and PO 4 3– ions easily under NIR irradiation, which was ascribed to the mild heat generated from graphene in the composite scaffold. The mild heat and the boosted Ca 2+ /PO 4 3– release could synergistically enhance the bone regeneration ability both in vitro and in vivo . The underlying mechanism was further explored and confirmed to be closely related to the upregulation of HSP 70, by which the MAPK/ERK signaling pathway was activated selectively. The favorable results demonstrate that the 3D-printed PEEK/graphene composite scaffold is promising in the applications of bone defect repair.
Peng Zhang,Xiaotong Yang,Tong Wang,Nobuyuki Imanishi,Osamu Yamamoto,Miao Wang
We demonstrate a novel rechargeable energy storage system having a metallic lithium negative electrode and a liquid–solid hybrid positive electrode of Fe 3+ /Fe 2+ /Fe in N,N-Dimethylformamide, which are separated by an impermeable NASICON–type Li 1.4 Al 0.4 Ge 0.2 Ti 1.4 (PO 4 ) 3 –epoxy resin composite film with a lithium ion conductivity of ca. 5.0 × 10 −4 S cm −1 . The discharge curve for the battery shows two plateaus. The first plateau corresponds to Li + FeCl 3 = LiCl + FeCl 2 , while the second one is associated with 2 Li + FeCl 2 = 2 LiCl + Fe. In the process of reduction of Fe 3+ to Fe 2+ , it delivers a stable discharge capacity of ca. 110 mAh g FeCl3 −1 with a Coulombic efficiency higher than 95% and is capable of enduring over 60 circles at a high current density of 1.0 mA cm −2 without any catalyst. Furthermore, a stable discharge capacity up to ca. 455 mAh g FeCl3 −1 is achieved for conversion of FeCl 3 /FeCl 2 /Fe with a three–electron reaction. This work demonstrates a proof of feasibility of hybrid liquid–solid hybrid positive electrode, since these reactions are reversible confirmed by x–ray diffraction patterns and EDX mapping test.
Qing Li,Wenbin Liu,Wen Hou,Xiaopei Wu,Wenying Wei,Jiawei Liu,Yihe Hu,Honglian Dai
The abundant neurovascular network in the periosteal fibrous layer is essential for regulating bone homeostasis and repairing bone defects. However, the majority of the current studies only focus on the structure or function, and most of them merely involve osteogenesis and angiogenesis, lacking an in-depth study of periosteal neurogenesis. In this study, a photothermal double-layer biomimetic periosteum with neurovascular coupling was proposed. The outer layer of biomimetic periosteum is a conventional electrospinning membrane to prevent soft tissue invasion, and the inner layer is an oriented nanofiber membrane to promote cell recruitment and angiogenesis. From the perspective of functional bionics, based on the whitlockite (WH) similar to bone composition, we doped Nd (the trivalent form of neodymium element) in it as the inducing element of photothermal response to prepare photothermal whitlockite ( [email protected] ). The sustained release of Mg 2+ in [email protected] can effectively promote the up-regulation of nerve growth factor (NGF) and vascular endothelial growth factor (VEGF). The release of Ca 2+ and PO 4 3− ions and photothermal osteogenesis jointly promote bone regeneration. Under the combined effect of structure and function, the formation of nerves, blood vessels, and related collagens greatly simulates the microenvironment of extracellular matrix and periosteum regeneration and ultimately promotes bone regeneration. In this study, physical and chemical characterization proved that the bionic periosteum has good flexibility and operability. The in vitro cell experiment and in vivo calvarial defect model verified that PPCL/ [email protected] biomimetic periosteum had excellent bone tissue regeneration function compared with other groups. Finally, PPCL/ [email protected] provides a new idea for the design of bionic periosteum.