Table 2.

Representative biomarkers of biomimetic functional materials of different cellular origins and their functions.

Cell type	Representative biomarkers	Functions	References
Red blood cells	CD47	Long-range looping	[41]
Platelets	P-selectin	Binding to CD44 on the tumor cell surface for active targeting	[76,77]
Macrophages	CD47 and tumor necrosis factor-α	Improve circulation time, target tumors and engage antitumor immunity	[78,79]
Neutrophils	Adhesion molecules (e.g. intercellular adhesion molecule-1)	Bind to inflamed cells and migrate to the site of inflammation	[80,81]
Dendritic cells	Major histocompatibility complex	Activation and maintenance of antigen-specific T cells by activating antigen-presenting cells and delivering peptide antigens	[82,83]
T cells	T-cell receptors	Localize and target tumors	[84]
Natural killer cells	Membrane proteins (e.g. RANKL or dNaM-1)	Induction of polarization of tumor-associated macrophages	[85,86]
Tumor cells	Plasma membrane proteins (including N-cadherin, Galectin 3 and adhesion molecules)	Immune escape and homologous targeting of tumor cells	[87,88]
Mesenchymal stem cells	CXC chemokine receptor 4 and hypoxia-inducible factor.	Tumor targeting and low immunogenicity	[89,90]
Bacteria	Pathogen-associated molecular patterns	Tumor targeting and activation of immunity	[7,91]