Hematopoietic organoids: Opportunities and challenges in modeling human hematopoiesis and diseases in vitro

Previous studies on hematopoiesis were mainly conducted in model animals. However, direct investigation of human hematopoiesis remains challenging due to limited access to human samples and ethical concerns. Traditional two-dimensional culture systems have provided valuable opportunities to study human hematopoiesis, but they fail to fully recapitulate the behaviors of hematopoietic cells and their interactions with niche cells as observed in vivo. In recent years, organoid technologies have emerged as a powerful approach for modeling hematopoietic development, maintenance, and diseases. By mimicking the key architectural and functional characteristics of native hematopoietic tissues, hematopoietic organoids (HOs) offer promising platforms for studying developmental hematopoiesis, modeling hematological diseases, performing drug screening, and generating functional hematopoietic cells. In this review, we summarize recent progress in HO construction, explore their potential applications in both basic research and clinical translation, and discuss current opportunities and remaining challenges in generating physiologically relevant HO models.