Application of a Novel Near Infrared-Fluorescence Giant Vesicle-and Polymerasome-based Tissue Marker for Endoscopic and Laparoscopic Navigation

Abstract

In this study, we describe the development of a novel tissue marker that can be injected from within the digestive tract by using an endoscopic instrument, and visualized using near-infrared (NIR) fluorescence imaging. The marker was prepared in three steps, (i) mixing NIR-fluorescent indocyanine green (ICG) with giant vesicles (GVs) of lecithin, (ii) suspending the ICG-containing giant vesicles (ICG-GV) in an oil phase dissolving polyglycerol-polyricinoleate (PGPR), and (iii) centrifugation of the suspension layered on a buffered solution to obtain a giant polymer vesicle (polymerasome) containing ICG-GV. We injected the tissue marker into the inner gastric surface of an anesthetized pig using an endoscopic syringe, and observed the injection site using a fluorescence laparoscopic camera. The diameter of the spot blur was approximately 2 cm over a 5-h period, demonstrating the utility of this procedure as a tissue marker for tumor marking, and suggesting its potential for assisting navigation during surgical procedures.

A Practical Guide to Preparation and Applications of Giant Unilamellar Vesicles Formed via Centrifugation of Water-in-Oil Emulsion Droplets

“…In addition to the small and/or large vesicles used in drug delivery systems, GUVs have been paid attention in medical applications. Hayashi et al attempted to produce a tissue marker for location identification during surgical navigation [39,86,87]. They encapsulated large vesicles bearing an infrared fluorescent dye in a polymeric GUV marker developed to locate gastric cancer.…”

Molecular Building Blocks and Their Architecture in Biologically/Environmentally Compatible Soft Matter Chemical Machinery

“…However, this fluorescent probe is subject to blur and bleaching. GV-based tissue markers, including ICG, are prepared using three steps 91 : i mixing of ICG with lecithin GVs;, ii suspension of the ICG-containing giant vesicles ICG-GV in an oil phase dissolving polyglycerol-polyricinoleate PGPR , and iii centrifugation of the suspension layered on a buffered solution to obtain a giant polymer vesicle polymerasome containing ICG-GV Fig. 9b .…”

pH-Tolerant giant vesicles composed of cationic lipids with imine linkages and oleic acids

“…[6][7][8] Vesicles are also useful as micro reaction elds for analysis in biological systems and as tissue markers. [9][10][11][12] In addition, it is well known that polymersomes of amphipathic polymers are more stable than vesicles composed of low-molecular-weight amphiphiles under various conditions. The shape of nanometer-sized polymersomes differs according to the composition of the polymer chain, and the affinity with cells depends on their shape; therefore, polymersomes are useful for nanomedicines.…”