Table 3.

Examples of in vitro tissue engineering approaches for treatment of volumetric muscle loss

Treatment Category	Target Tissue for Ablation	Treatment	Major Findings	Reference
Acellular Scaffolds	Canine gastrocnemius muscle and Achilles tendon bundle	Porcine small intestinal submucosa (SIS) decellularized scaffold for 6 months	Vascularized and innervated skeletal muscle had formed at the implantation site Scaffold-treated group had a contractile force that was 48% of the contralateral musculotendinous junction	[145]
	Rat abdominal muscle	Porcine SIS decellularized scaffold for 26 weeks	Complete recovery in maximal contractile force to native tissue	[146]
	Rat tibialis anterior muscle	Porcine urinary bladder matrix	Limited muscle formation and scaffold-mediated fibrosis	[148]
	Mouse tibialis anterior muscle	Porcine urinary bladder matrix or nanofibrillar rat collagen scaffold	No benefit of decellularized matrix or collagen scaffolds on muscle or vascular regeneration	[153]
Cell-Seeded Scaffolds	Mouse latissimus dorsi muscle	Muscle-derived cells (MDCs) seeded on porcine urinary bladder matrix	Higher max tetanic force compared to the control ablated muscle group at 1 month At 2 months, cell-seeded scaffolds with prolonged bioreactor conditioning + second application of MDCs showed sustained functional benefit	[149]
	Mouse tibialis anterior muscle	Muscle stem cells, endothelial cells (ECs) and muscle resident cells in decellularized muscle scaffold	Addition of ECs and other support cells promoted higher force production in the ablated muscle, compared to scaffolds without ECs	[150]
	Mouse latissimus dorsi muscle	Rat muscle progenitors in bladder acellular matrix with stretch pretreatment	Significant recovery of force generation after 2 months, when compared to the no treatment control group	[36]
	Rat tibialis anterior muscle	Rat muscle progenitors in bladder acellular matrix with stretch pretreatment	Large variability in functional response, with positive responders showing 61% improvement in function, compared to non-repaired animals The variability was partially attributed to differential immune response	[37]