Table 2.

Summary of in vivo skeletal muscle repair and vascularization via implantation of in vitro engineered tissues.

Cell source	Cell types	Scaffold	Model	In vitro function	In vivo function	Vascularization	Effects	Ref.
Rat	Neonatal MPCs	Fibrin/ Matrigel	Dorsal skin-fold window chamber	47.9±4.1 mN/mm2	65.7±8.9 mN/mm2	Host-derived vasculature. Implant highly vascularized and perfused	Continued myogenesis, vascularization, and increase in force generation during 2wk implantation period	[210]
	3wk rat MPCs	Bladder acellular matrix	TA volumetric muscle loss	N/A	Yes	Not reported	Positive responders show ~60% functional improvement to non- treated VML injury. Negative responders show no improvement	[171]
	MPCs and MSCs	Laminin	TA volumetric muscle loss	121±9	Yes	Host-derived vasculature. Robust capillary network	Myotendinous junctions show greater maturation. Improved TA force but not to level of control	[341]
	Adult soleus MPCs	Fibrin	Femoral vascular pedicle	N/A	35.4±62.2 mN/mm2	Host-derived vasculature	3wks post-implantation, muscle shows mature sarcomeres	[306]
	Adult soleus MPCs	Fibrin	Femoral vascular pedicle	N/A	Yes	Host-derived vasculature	Including femoral nerve stump in implant increases function 5-fold compared to no-stamp implants	[311]
Mouse	C2C12 + Fibs + HUVECs	PLLA/ PGLA	Subcutaneous, quadriceps and abdominal wall	N/A	N/A	Host and donor anastomosis	Tri-culture results in greastest vascularization	[302]
	C2C12 + Fibs + HUVECs	PLLA/ PGLA	Abdominal wall	N/A	~0.1 mN/ mm2	Host and donor anastomosis	Tissues kept in culture for 3wks show better vsacular infiltration than those implanted after 1 day	[303]
	C2C12	Fibrin	Gluteus	N/A	N/A	Agrin promotes greater host vasculature infiltration	Pre-treatment with agrin promotes acetylcholine receptor clustering and innervation by host nerves	[236]
Human	MPCs	Porcine Bladder submucosa	Latissimus Dorsi	ND	0.9±0.1 mN/ mm2	Not reported	Function only seen after cyclic stretch. Implant force increases from 2 to 4wks post implantation	[242]

MPCs, muscle progenitor cells. MSCs, mesenchymal stem cell. HUVECs, human umbilical vein endothelial cell. PLLA, poly-(L-lactic acid). PLGA, polylactic-co-glycolic acid. VML, volumetric muscle loss. N/A, not assessed. ~, estimated 14 based on figure in paper.