Exosomes are lipid-bilayer enclosed vesicles with diameters of 30–150 nm, which play a pivotal role in cell communication by transporting their cargoes such as proteins, lipids, and genetic materials. In recent years, exosomes have been under intense investigation, as they show great promise in numerous areas, especially as bio-markers in liquid biopsies. However, due to the high heterogeneity and the nano size of exosomes, the separation of exosomes is not easy. This review will deliver an outline of the conventional methods and the microfluidic-based technologies for exosome separation. Particular attention is devoted to microfluidic devices, highlighting the efficiency of exosome isolation by these methods. Additionally, this review will introduce advances made in the integrated microfluidics technologies that enable the separation and analysis of exosomes.

Chimeric antigen receptor T (CAR-T) cells are a type of tumor immunotherapy that is a breakthrough technology in the clinical treatment of tumors. The basic principle of this method is to extract the patient's T cells and equip them with targeting recognition receptors of tumor cells and return them to the patient's body to recognize and kill tumor cells specifically. Most CAR-T cell therapies treat hematological diseases such as leukemia or lymphoma and achieved encouraging results. The safety and effectiveness of CAR-T cell technology in solid tumor treatment require to be improved, although it has demonstrated promising efficacy in treating hematological malignancies. It is worth noting that certain patients may experience fatal adverse reactions after receiving CAR-T cell therapy. At present, the difficulty of this therapy mainly lies in how to reduce adverse reactions and target escape effects during the course of treatment. The improvement of CAR-T cell therapy mainly focuses on improving CAR-T structure, finding suitable tumor targets and combining them with immune checkpoint inhibitors to the enhance efficacy and safety of treatment. The problems in the rapid development of CAR-T cell therapy provide both obstacles and opportunities. The present review elaborates on the clinical application of CAR-T cell technology to provide a reference for clinical practice and research on tumor treatment.

Exosomes are small vesicles with a diameter of ~40-100 nm that are secreted by the majority of endogenous cells under normal and pathological conditions. They contain abundant proteins, lipids, microRNAs, and biomolecules such as signal transduction molecules, adhesion factors and cytoskeletal proteins, and play an important role in exchanging materials and transmitting information between cells. Recent studies have shown that exosomes are involved in the pathophysiology of leukaemia by affecting the bone marrow microenvironment, apoptosis, tumour angiogenesis, immune escape and chemotherapy resistance. Furthermore, exosomes are potential biomarkers and drug carriers for leukaemia, impacting the diagnosis and treatment of leukaemia. The present study describes the biogenesis and general characteristics of exosomes, and then highlight the emerging roles of exosomes in different types of leukaemia. Finally, the value of clinical application of exosomes as biomarkers and drug carriers is discussed with the aim to provide novel strategies for the treatment of leukaemia.