Janus particles with an anisotropic structure have emerged as a focus of intensive research due to their diverse composition and surface chemistry, which show excellent performance in various fields, especially in biomedical applications. In this review, we briefly introduce the structures, composition, and properties of Janus particles, followed by a summary of their biomedical applications. Then we review several design strategies including morphology, particle size, composition, and surface modification, that will affect the performance of Janus particles. Subsequently, we explore the synthetic methodologies of Janus particles, with an emphasis on the most prevalent synthetic method (surface nucleation and seeded growth). Following this, we highlight Janus particles in biomedical applications, especially in drug delivery, bio-imaging, and bio-sensing. Finally, we will consider the current challenges the materials face with perspectives in the future directions.

具有各向异性结构的Janus颗粒由于其不同的组成和表面化学特性已成为广泛研究的焦点，在各种领域，特别是在生物医学应用中均显示出优异的性能。在本文中，我们简要介绍了Janus颗粒的结构，组成和性质，然后概述了其生物医学应用。然后，我们回顾了几种会影响Janus颗粒性能的设计策略，包括形态，粒度，组成和表面改性。随后，我们探索Janus颗粒的合成方法，重点是最流行的合成方法（表面成核和种子生长）。接下来，我们重点介绍Janus颗粒在生物医学应用中的应用，特别是在药物输送，生物成像，和生物传感。最后，我们将以未来的方向来考虑材料面临的当前挑战。