Active transport of gas molecules is critical to preserve the physiological functions of organisms. Oxygen, as the most essential gas molecule, plays significant roles in maintaining the metabolism and viability of cells. Herein, we report a nanomotor-based delivery system that combines the fast propulsion of acoustically propelled gold nanowire nanomotors (AuNW) with the high oxygen carrying capacity of red blood cell membrane-cloaked perfluorocarbon nanoemulsions (RBC-PFC) for active intracellular delivery of oxygen. The oxygen delivery capacity and kinetics of the AuNW nanomotors carrying RBC-PFC (denoted as "Motor-PFC") are examined under ultrasound field. Specifically, the fast movement of the Motor-PFC under an acoustic field accelerates intracellular delivery of oxygen to J774 macrophage cells. Upon entering the cells, the oxygen loaded in the Motor-PFC is sustainably released, which maintains the cell viability when cultured under hypoxic conditions. The acoustically propelled Motor-PFC leads to significantly higher cell viability (84.4%) over a 72 h period, compared to control samples with free RBC-PFC (44.4%) or to passive Motor-PFC (32.7%). These results indicate that the Motor-PFC can act as an effective delivery vehicle for active intracellular oxygen transport. While oxygen is used here as a model gas molecule, the Motor-PFC platform can be readily expanded to the active delivery of other gas molecules to various target cells.

As the most common nutritional disorder, iron deficiency represents a major public health problem with broad impacts on physical and mental development. However, treatment is often compromised by low iron bioavailability and undesired side effects. Here, we report on the development of active mineral delivery vehicles using Mg-based micromotors, which can autonomously propel in gastrointestinal fluids, aiding in the dynamic delivery of minerals. Iron and selenium are combined as a model mineral payload in the micromotor platform. We demonstrate the ability of our mineral-loaded micromotors to replenish iron and selenium stores in an anemic mouse model after 30 days of treatment, normalizing hematological parameters such as red blood count, hemoglobin, and hematocrit. Additionally, the micromotor platform exhibits no toxicity after the treatment regimen. This proof-of-concept study indicates that micromotor-based active delivery of mineral supplements represents an attractive approach toward alleviating nutritional deficiencies.