Muscle and nerve tissue damage can elicit a significant loss of function and poses as a burden for patients and healthcare providers. Even for tissues, such as the peripheral nerve and skeletal muscle, that harbor significant regenerative capacity, innate regenerative processes often lead to less than optimal recovery and residual loss of function. The reasons for poor regeneration include significant cell damage secondary to oxidative stress, poor recruitment of resident stem cells, and an unfavorable microenvironment for tissue regeneration. Stem cell-based therapy was once thought as a potential therapy in tissue regeneration, due to its self-renewal and multipotent capabilities. Early advocates for cellular-based therapy pointed to the pluripotent nature of stem cells, thus eluding to its ability to differentiate into resident cells as the source of its regenerative capability. However, increasing evidence has revealed a lack of engraftment and differentiation of stem cells, thereby pointing to stem cell paracrine activity as being responsible for its regenerative potential. Stem cell-conditioned media houses biomolecular factors that portray significant regenerative potential. Amniotic-derived stem cell-conditioned media (AFS-CM) has been of particular interest because of its ease of allocation and in vitro culture. The purpose of this review is to report the results of studies that assess the role of AFS-CM for nerve and muscle conditions. In this review, we will cover the effects of AFS-CM on cellular pathways, genes, and protein expression for different nerve and muscle cell types.
Microengineering Hydrogels for Stem Cell Bioengineering and Tissue Regeneration
