Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive pulmonary disorder characterized by fibrotic scarring, hypoxemia, and dyspnea. Although oxygen therapy is widely used to relieve acute dyspnea, it faces limitations such as oxygen toxicity and patient immobility. To address these challenges, this study developed upconversion-based microrobots capable of mitigating IPF through in situ oxygen generation. These microrobots consist of Chlamydomonas reinhardtii algae functionalized with upconversion nanoparticles. Upon inhalation and exposure to near-infrared light, the microrobots convert the incident light into red visible light, driving photosynthetic oxygen production at a rate of 0.298 ± 0.005 mg·(L·min)⁻¹. Moreover, their autonomous mobility within the mucus enhances the uniformity of oxygen distribution and prolongs retention by evading pulmonary macrophage clearance. In a murine model of IPF, the microrobots effectively alleviated hypoxia, as evidenced by reduced hypoxia-inducible factor 1-alpha (HIF-1α) expression in fibrotic lung tissues and elevated blood oxygen saturation. This platform presents an efficient and promising strategy for oxygen therapy in IPF and broader pulmonary oxygen-dependent applications.

Micro/nanomotors (MNMs) have recently emerged as highly promising drug delivery vehicles, showing great potential for biomedical applications. MNMs are typically classified based on their driving mechanisms, and one notable category is gas-driven MNMs, which are self-propelled at the micro/nano scale by gases generated through chemical reactions. These motors can effectively overcome various physiological barriers by utilizing unique physiological actions and driving forces in vivo, gas-driven MNMs offer significant advantages in treating diseases such as tumors and thrombosis. This review first explores the underlying mechanisms of gas-driven MNMs, then discusses their recent applications in overcoming physiological barriers. Finally, it analyses their future prospects and advantages, aiming to inspire further research and accelerate clinical translation in the biomedical field.