Table 1 Common themes in MSC biodistribution research

Increased homing after intra-arterial delivery compared with intravenous delivery?

Kidney

[33, 34]

Joints

[32]

Stroke

[30]

Other (many) tissues

[31]

Side effects of intra-arterial versus intravenous delivery?

Incorporation into vessel wall

[23, 35]

Obstruction of microvessels

[38]

Vascular occlusion

[39]

Targeting of vessel wall and vessel-associated tissues?

Lungs, lymph nodes, intestine

[47]

Targeting of tissues for regeneration

Myocardium

[18, 48–55]

 Beta1 integrins

[48, 49]

 CCL2, monocytes

[52]

Kidney

[33, 56–63]

Gut and liver

[64–67]

Skin

[44, 68–71]

 CCL21

[44]

 JAM-A

[68]

Brain

[72–75]

 P/E selectin (CD44)

[73]

 CXCR4/flk-1/EPO-R

[74]

Homing to bone marrow

Bone marrow

[76–81]

 HCELL/E-selectin

[15]

 Subendothelial localization

[79]

Biodistribution to the immune system?

Macrophages

[37, 41, 42]

Dendritic cells

[38]

T cells

[39]

Unknown target cells

 Idoleamine desoxygenase

[43]

 Prostaglandin E2

[37, 41]

Elimination mechanisms?

Antibody formation

[6]

Phagocytes

[102]

Influence of radiation on homing?

Increased in brain, heart, bone marrow, and muscles

[43, 82]

Homing in malignancies?

Tumor

[83–85, 87–92]

 Mediated by CCL25

[88]

 Mediated by sodium iodide symporter under the control of RANTES/CCL-5 promoter

[87]

 Homed MSCs form tumor-associated fibroblasts

[90]

Formation of microvesicles

Microvesicles may contribute to/be part of MSC biodistribution

[14, 63, 93–97]

 Mediated by horizontal transfer of microRNAs

[96]