Summary of positional error metrics.

Microinjection enables the precise delivery of substances into specific areas of small animals, such as zebrafish, whose xenograft models can be a promising platform for developing rapid and personalized cancer therapies. However, manual microinjection exhibits experimental variability and low reproducibility, as it relies on the expertise of researchers. To address these problems, automated microinjection systems have been developed in recent years. In this study, we propose a microrobotic system based on an image recognition AI model that extracts key feature points to define the pericardial space in zebrafish larvae at 2 days post-fertilization. Using the geometric relationships among feature points, the system optimizes the glass capillary insertion motion for precise microinjection. We also introduced a batch agarose microplate that prevents dehydration while stabilizing the larvae, which improved the survival rate compared to the conventional plate (log-rank test, p n = 1129) for microinjection and a 92.1% (n = 1143) for survival. Moreover, we successfully injected colorectal cancer cell lines (HCT116 and SW620) into the pericardial space, resulting in an engraftment success rate of 96.2% (n = 610). Our system exhibits higher success rates and reproducibility compared to manual microinjection, allowing even inexperienced researchers to perform stable injections. These results demonstrate that our system effectively enhances the efficiency and reproducibility of experiments involving zebrafish-based cancer research and xenograft model generation.显微注射（Microinjection）可将物质精准递送至小型动物的特定区域。以斑马鱼为例，其异种移植模型（xenograft model）可作为开发快速个性化癌症治疗方案的极具前景的平台。然而，手动显微注射依赖研究者的操作经验，存在实验变异性大、可重复性低的缺陷。为解决上述问题，近年来诸多自动化显微注射系统相继被开发。本研究提出一种基于图像识别AI模型的微机器人系统，该模型可提取关键特征点，以定位受精后2天的斑马鱼幼体的心包腔。该系统借助特征点间的几何关系，优化玻璃毛细管的插入动作，实现精准显微注射。本研究还开发了一款批量式琼脂糖微孔板，可在固定斑马鱼幼体的同时避免其脱水；与传统微孔板相比，该装置可提升幼体存活率（对数秩检验，log-rank test，p n = 1129），其中显微注射组存活率达92.1%（n = 1143）。此外，本研究成功将结直肠癌细胞系（colorectal cancer cell lines）HCT116及SW620注射至心包腔，移植成功率达96.2%（n = 610）。相较于手动显微注射，本系统的注射成功率与可重复性更优，即使是经验不足的研究者也可完成稳定的显微注射操作。上述结果表明，本系统可有效提升基于斑马鱼的癌症研究及异种移植模型构建相关实验的效率与可重复性。