From stem cell transplantation to stem cell-based drug delivery systems targeting hematological malignancies: recent advances and clinical considerations.

Hematopoietic stem cell transplantation (HSCT) is a promising treatment option for hematological malignancies. Despite its curative potential, it faces clinical challenges, including relapse and graft-versus-host disease (GVHD). Systemic toxicity due to chemotherapy is a significant problem in patients with hematological malignancies. Stem cell-based drug delivery can precisely deliver drugs to tumor sites, thereby increasing local drug toxicity, which may alleviate relapse and systemic toxicity. This review integrates and critically examines the recent clinical advances in HSCT and its challenges. Autologous HSCT is constrained by the risk of relapse, whereas allogeneic HSCT is limited by donor availability and GVHD complications. Additionally, we highlight both the immunomodulation of mesenchymal stem cells (MSCs) in GVHD and the therapeutic potential of induced pluripotent stem cells (iPSCs). Furthermore, we explored stem cell-based drug delivery systems focusing on three primary strategies: (1) stem cells as intrinsic carriers, (2) stem cell-derived extracellular vesicles (EVs), and (3) stem cell membrane-derived biomimetic vesicles. While stem cell therapies hold promise, issues include the heterogeneity of stem cell sources, complexity of the cultivation process, and long-term safety issues. Future research should focus on large-scale technologies, stem cell engineering techniques, and combination therapies to facilitate clinical translation.