Soft Robots Featuring Cy5 Enable “Intake and Work” Imaging Technique for Precise Intraoperative Navigation of Gastric Lesions

In a groundbreaking advancement poised to redefine the landscape of laparoscopic surgery for early gastric cancer, researchers at Zhejiang University have unveiled an innovative technique employing fluorescent soft robots embedded with Cy5 for precise intraoperative navigation. Published in the prestigious journal Cyborg and Bionic Systems on April 11, 2025, this pioneering study addresses a long-standing challenge in minimally invasive gastric cancer surgery: the accurate localization of lesions confined to the stomach’s mucosal and submucosal layers, which are notoriously elusive under conventional laparoscopic visualization.

Early gastric cancer, often limited to the innermost layers of the stomach wall, presents a formidable obstacle during laparoscopic procedures due to the invisibility of these tumors on the serosal surface viewed intra-abdominally. Historically, surgeons have relied on adjunctive measures such as preoperative dye injections or magnetic clip systems to demarcate tumor sites, methods which suffer from limitations including technical complexity, limited persistence of markers, and difficulties in intuitive lesion detection. Addressing these shortcomings, the Zhejiang University team, led by Lifeng He, has developed a novel strategy that harnesses the unique capabilities of miniaturized soft robots labeled with the near-infrared fluorescent dye Cy5.

This novel approach operates by first implanting a biocompatible metal clip at the gastric lesion during preliminary endoscopic examination. Patients then ingest a capsule containing the soft robots before surgery. These robots, designed with magnetic properties and fluorescent markers, autonomously circulate within the gastric cavity, selectively congregating around the implanted metal clip in response to an applied magnetic field. The resulting fluorescence, observable under near-infrared (NIR) imaging during surgery, distinctly illuminates the tumor region, enabling surgeons to identify and precisely target cancerous tissues with unprecedented accuracy and ease.

The engineers behind this technology emphasize the soft robots’ robust mobility and adhesion characteristics. Despite the highly acidic and dynamic stomach environment, the soft robots demonstrate exceptional capability to navigate intragastric fluid currents, locate the metal clips, and remain firmly attached. Remarkably, their fluorescence signal endures for over eight hours, surpassing typical preoperative fasting durations and ensuring that the tumor remains vividly marked throughout the operative timeline. Such lasting luminescence represents a significant advancement over traditional markers, which often degrade or dissipate too rapidly for practical clinical use.

Validation of this technology was conducted rigorously through animal models; clips were surgically implanted into the stomach walls of rats, followed by oral administration of the Cy5-labeled soft robots. Fluorescent imaging confirmed the robots’ successful accumulation at the clip sites, effectively demarcating the lesion locations. These results suggest that the soft robot system offers a superior and less invasive alternative to existing tumor localization techniques, minimizing procedural complexity and enhancing overall surgical workflow and patient safety.

Beyond its immediate clinical implications, the fabrication technique of these fluorescent soft robots is noteworthy for its simplicity and cost-effectiveness. The researchers describe a streamlined manufacturing process capable of producing these micro-scale devices with consistent quality, leveraging materials compatible with biological tissues and capable of maintaining their structural and functional integrity in harsh gastric conditions. This ease of production bodes well for scalability and eventual clinical translation.

The integration of magnetic responsiveness with long-lasting fluorescent signaling within the soft robots represents a significant breakthrough in medical robotics and imaging. Unlike conventional rigid micro-robots, these soft constructs display flexibility and agility, crucial for maneuvering within complex and confined biological environments like the stomach. Their adhesive mechanisms ensure that once localized at the clip, they maintain position despite peristaltic movements and gastric secretions, enhancing the reliability of surgical navigation.

This research not only bridges the gap between engineering and surgery but also opens new avenues for smart robotic-assisted diagnostic and therapeutic interventions in gastrointestinal oncology. The technology’s versatility could extend to other minimally invasive procedures requiring precise lesion localization, potentially transforming how surgeons approach a variety of cancers or pathological conditions that remain challenging to identify intraoperatively.

Furthermore, the sustained and reliable intraoperative fluorescence offered by these soft robots elevates the standard for real-time tumor visualization. By employing near-infrared signals, the system allows for deeper tissue penetration, reduced background interference, and superior contrast compared to visible light-based dyes, significantly enhancing surgical precision. This facilitates more thorough tumor resections while preserving healthy tissue, ultimately improving patient outcomes and reducing recurrence rates.

The authors envisage that with further refinement and clinical testing, the soft robot platform could be integrated into standard laparoscopic toolsets, complemented by existing imaging infrastructure. This integration promises a seamless user experience enabling surgeons to swiftly identify gastric lesions with minimal additional preparation or complexity, thereby streamlining preoperative workflows and reducing operative time.

This study was undertaken by a multidisciplinary team including Lifeng He, Yu Pan, Wei Jin, Rong Tan, Yanan Xue, Danying Sun, Jingyu Zhang, Pingyu Xiang, Qin Fang, Yue Wang, Rong Xiong, Haojian Lu, and Songmei Lou. Funded by prominent bodies like the National Natural Science Foundation of China, the Key R&D Program of Zhejiang, and supported by other state key laboratories as well as the Xiaomi Foundation, the research stands as a testament to the impactful collaborations advancing medical technology today.

In summary, this novel fluorescent soft robot system represents a paradigm shift in the intraoperative localization of gastric lesions, delivering enhanced accuracy, durability, and ease of use. By overcoming the limitations of current methodologies, this technology not only promises to improve surgical outcomes for early gastric cancer patients but also heralds a new era of smart, robotics-enabled gastrointestinal surgery. The full paper titled “Soft Robots with Cy5: An ‘Intake and Work’ Imaging Technique for Intraoperative Navigation of Gastric Lesion” is available in Cyborg and Bionic Systems and has been assigned DOI: 10.34133/cbsystems.0212.

Subject of Research: Intraoperative localization of gastric lesions using fluorescent soft robots labeled with Cy5.

Article Title: Soft Robots with Cy5: An “Intake and Work” Imaging Technique for Intraoperative Navigation of Gastric Lesion.

News Publication Date: April 11, 2025.

Web References: DOI: 10.34133/cbsystems.0212

Image Credits: Lifeng He, Zhejiang University.

Keywords: Applied sciences and engineering, Health and medicine.

Tags: biocompatible materials in medical deviceschallenges in gastric cancer surgeryCy5 fluorescent dye applicationsearly gastric cancer detection methodsfluorescent imaging techniques in medicinegastric lesion localization techniquesintraoperative navigation for gastric cancerlaparoscopic surgery advancementsminimally invasive surgical innovationssoft robotics in surgerysurgical technology and roboticsZhejiang University research breakthroughs