目前，针对如何获取可降解生物材料在动物模型体内降解和代谢过程数据这一关键科学问题，传统的研究方法是在固定时间节点处死动物模型，然后收集不同时间段的动物实验结果并进行统计分析，但是由于相关实验数据并不是来源于同一动物模型的连续观测结果，因此最终的统计分析结果并不能精确反映可降解生物材料在体内降解与代谢的真实过程。本项目计划联合英国UCL的Thanh教授通过技术共享，优化制备工艺，开发一种适合生物体内长时间成像的新型纳米探针---近红外硫化铅量子点。本项目充分近红外成像技术在活体成像的技术优势，通过将新型近红外硫化铅量子点标记生物可降解材料--胶原，利用动物模型，进一步研究生物可降解材料体内降解与代谢过程的实时定量结果，为开发更符合临床需要的新型生物可降解材料提供可靠的体内数据基础。

Although degradable biomaterials have been widely applied in bone repair engineering, challenges remain in real-time observing those biomaterials in vivo degradation. However, controlled material development is limited, as degradation in vivo is more complex than in vitro, and in vitro assays are rarely adequate measures of implant behavior. Therefore, myriad endeavors have been devoted to develop on monitoring materials in vivo degradation behavior. Most of importantly, current methods is to sacrifice numerous animals at various time intervals in order to gain in vivo data, which often leads to inaccurate conclusions, as there are not a real-time and continues result from the same experimental animal. Thus, long-time in vivo tracking of degradable materials still a huge challenge..As a non-invasive imaging technology, near infrared (NIR) imaging is suitable for in situ monitoring of implanted biomaterials based on its deeper tissue penetration (lower absorbance) and lower auto-fluorescence background. With the development of nanotechnology, NIR imaging is a promising technique of tracking biomaterial in vivo degradation based on near infrared fluorescence nanoprobe. In particular, the second near-infrared window (NIR-II, 1000-1400 nm, photon energy: 1.24-0.89 eV) have become increasingly attractive for in vivo fluorescence imaging due to the greatly reduced light absorption and scattering together with nearly zero biological auto-fluorescence background. As a result, NIR-II in vivo imaging can provide the deepest light penetration into body with greatly increased image contrast, fidelity and resolution. In this study, collagen scaffolds was firstly conjugated with NIR-II fluorescent lead sulphide (PbS) quantum dots (QDs), and then were tracked its degradation in animals model by NIR-II imaging. Our project is not only enable to increase the accuracy of in vivo data from animals, but also pave a novel way for developing next generation biomaterials.