Umbilical vessel catheter retro-exchange technique (U-RET) for repeat use of the umbilical artery for neonatal vascular intervention: Technical note

A high flow arteriovenous shunts in newborns may require urgent endovascular treatment right immediately after delivery if high output cardiac failure is resistant to medical treatment. The umbilical approach is often the first choice of the access route for endovascular treatment in the newborn. It is, however, not infrequent that the patient has an extensive lesion, which necessitates a second session of treatment because of the limitation of the usable amount of the contrast material in one session. In such a case, re-puncturing the femoral artery is difficult and carries the risk of leg ischemia. On the other hand, leaving the umbilical sheath for the second procedure carries risks of infection, thrombosis, and vessel injury. Herein we introduce our umbilical vessel catheter (UVC) retro-exchange technique (U-RET) in which we replace the umbilical sheath to a 3.5Fr UVC at the end of the first endovascular procedure to preserve the umbilical artery access and prepare for the repeated use. We believe that this method minimizes the risks of infection and vessel injury.

Fabrication and Investigation on the Polyimide/Al2O3 Composite Films via Ion Exchange Technology

Polyimide/Al2O3 films were prepared by the surface modification with different hydrolysis time, ion exchange technique and heat treatment using polyimide films as the substrates and aluminum chloride as the precursor of Al2O3. The morphology, thermal properties and electrical properties of the composite films were characterized and tested. The results indicated the alumina distributed in certain thickness on the surface of the films and there was a clear interface layer between the alumina layer and the substrate. The breakdown strength of the composite films maintains the excellent properties of the pristine film while the thermal and corona-resistant time properties of composite films were better than the pristine film due to introducing aluminum oxide. The composite film which used KOH to treat for 90 min has the longest corona-resistant time (101.2 min), which was almost 10 times longer than the pristine film.

Novel Epigallocatechin-3-Gallate (EGCG)-Loaded Mesoporous Bioglass Scaffolds for Bone Recruitment Applications

Bioglass-based material has been widely used in the field of biomedical science. In this study, the proper concentration of epigallocatechin-3-gallate (EGCG) for a mesoporous bioglass (MBG) scaffold was determined based on the sponge replication method. The fabrication procedure performed using a foam exchange technique resulted in an interconnected network of pores scaffolds with no cracks. In the minimum bactericidal concentrations of the bacteria assessed, the antibacterial concentration of EGCG against E. coli (200 μg/mL) was higher than that against S. aureus (25 μg/mL). The MBG and EGCG-MBG scaffolds exhibited excellent apatite mineralization and drug release abilities (the highest cumulative drug release from the EGCG-MBG scaffold was 75.37%). Thus, a 200 μg/mL EGCG can prevent cell apoptosis and directly enhance cell proliferation. Hence, a low-dose EGCG-MBG scaffold is another option for bone recruitment material.