影响外泌体的细胞吸收率的因素有哪些？请给出参考资料

影响外泌体的细胞吸收率的因素包括外泌体的大小、表面分子的表达、细胞外环境pH值、细胞类型等。具体参考资料如下：

1. Kooijmans SA, Schiffelers RM, Zarovni N, et al. Modulation of tissue tropism and biological activity of exosomes and other extracellular vesicles: New nanotools for cancer treatment. Pharmacol Res. 2016;111:487-500.

2. Lai CP, Breakefield XO. Role of exosomes/microvesicles in the nervous system and use in emerging therapies. Front Physiol. 2012;3:228.

3. Tkach M, Théry C. Communication by extracellular vesicles: Where we are and where we need to go. Cell. 2016;164(6):1226-1232.