Co-construction of advanced sulfur host by implanting titanium carbide into Aspergillus niger spore carbon

Bioactive mesoporous silica nanoparticle-functionalized titanium implants with controllable antimicrobial peptide release potentiate the regulation of inflammation and osseointegration

Bacterial infection and delayed osseointegration are two major challenges for titanium-based orthopedic implants. In the present study, we developed a functionalized titanium implant Ti-M@A by immobilizing antimicrobial peptide (AMP) HHC36-loaded diselenide-bridged mesoporous silica nanoparticles (MSNs) on the surface, which showed good long-term and mechanical stability. The functionalized implants can realize the sustained release of AMP over 30 days and exhibit over 95.71 % antimicrobial activity against four types of clinical bacteria (S. aureus, E. coli, P. aeruginosa and MRSA), which arose from the capability to destroy the bacterial membranes. Moreover, Ti-M@A can efficiently inhibit the biofilm formation of the bacteria. The functionalized implants can also significantly promote the osteogenic differentiation of mouse bone marrow-derived mesenchymal stem cells (mBMSCs) because of the Se in MSNs. Notably, it can trigger macrophages toward M2 polarization in vitro by scavenging ROS in LPS-activated macrophages. Consequently, in vivo assays with infection and non-infection bone defect models demonstrated that such bioactive implants can not only kill over 98.82 % of S. aureus, but also promote osseointegration. Hence, this study provides a combined strategy to resolve bacterial infection and delayed osseointegration for titanium implants.

Ternary Deep Eutectic Solvent (DES) with a Regulated Rate-Determining Step for Efficient Recycling of Lithium Cobalt Oxide

Deep eutectic solvents (DESs) have attracted extensive research for their potential applications as leaching solvent to recycle valuable metal elements from spent lithium ion batteries (LIBs). Despite various advantages like being economical and green, the full potential of conventional binary DES has not yet been harnessed because of the kinetics during leaching. Herein, we consider the fundamental rate-determining-step (RDS) in conventional binary DES and attempt to design ternary DES, within which the chemical reaction kinetics and diffusion kinetics can be regulated to maximize the overall leaching rate. As a proof of concept, we show that the ternary choline chloride/succinic acid/ethylene glycol (ChCl/SA/EG) type ternary DES can completely dissolve LCO powder at 140 °C in 16 h. By systematically studying the leaching process at various conditions, the energy barrier during leaching can be calculated to be 11.77 kJ/mol. Furthermore, we demonstrate that the extraction of the cobalt ions from the leaching solution can be directly achieved by adding oxalic ions without neutralizing the solution. The precipitate can be used to regenerate LCO with high purity. The recycled materials show comparable electrochemical performance with commercial LCO. Our design strategy of ternary DES with regulated RDS is expected to have both scientific and technological significance in the field of hydrometallurgical recycling of LIBs.