MicBall800-coated metal clip as a novel fluorescent marker for image-guided laparoscopic surgery

Accurate tumor localization is crucial for the success of minimally invasive surgery, as it minimizes the resection of normal tissues surrounding tumors. Traditional methods for marking gastrointestinal (GI) tumors, such as ink tattooing, intraoperative gastroscopy or colonoscopy, and placement of metal clips, have major drawbacks in their application in laparoscopic surgery. Therefore, the development of safe and easy-to-operate marking methods for accurate and real-time detection of GI tumors during laparoscopic surgery remains an ongoing challenge. Here, we propose a new fluorescent metal clip (MicBall800 clip) for noninvasive and precise fluorescence marking of GI tumors. First, we prepared a poly(methyl methacrylate) microball with small, multiple, and separated pores in its internal structure, and near-infrared fluorescence dye (IRDye800CW) and human serum albumin complex were loaded into the pores. This near-infrared-dye-loaded poly(methyl methacrylate) microball (MicBall800) was then coated onto the surface of the metal clips to produce a highly fluorescent MicBall800 clip. Safety and biocompatibility tests of the MicBall800 clip were conducted by the Korea Testing Certification Institute. The MicBall800 clip was evaluated in vivo using a porcine model. The MicBall800 clip passed safety and biocompatibility tests. The MicBall800 clip could be easily marked at the target sites without causing any side effects and was detected in real time during the laparoscopic operation. The data obtained from the safety and biocompatibility tests and the in vivo animal study indicate that the MicBall800 clip can be an important advancement in minimally invasive and precision surgery for GI cancers.