Decellularized Fetal Matrix Suppresses Fibrotic Gene Expression and Promotes Myogenesis in a Rat Model of Volumetric Muscle Loss

Abstract

Background: Traumatic muscle loss often results in poor functional restoration. Skeletal muscle injuries cannot be repaired without substantial fibrosis and loss of muscle function. Given its regenerative properties, the authors evaluated outcomes of fetal tissue-derived decellularized matrix for skeletal muscle regeneration. The authors hypothesized that fetal matrix would lead to enhanced myogenesis and suppress inflammation and fibrosis. Methods: Composite tissue composed of dermis, subcutaneous tissue, and panniculus carnosus was harvested from the trunk of New Zealand White rabbit fetuses on gestational day 24 and from Sprague-Dawley rats on gestational day 18 and neonatal day 3, and decellularized using a sodium dodecyl sulfate–based negative-pressure protocol. Six, 10-mm-diameter, full-thickness rat latissimus dorsi wounds were created for each treatment, matrix was implanted (excluding the defect groups), and the wounds were allowed to heal for 60 days. Analyses were performed to characterize myogenesis, neovascularization, inflammation, and fibrosis at harvest. Results: Significant myocyte ingrowth was visualized in both allogeneic and xenogeneic fetal matrix groups compared to neonatal and defect groups based on myosin heavy chain immunofluorescence staining. Microvascular networks were appreciated within all implanted matrices. At day 60, expression of Ccn2, Col1a1, and Ptgs2 were decreased in fetal matrix groups compared to defect. Neonatal matrix-implanted wounds failed to show decreased expression of Col1a1 or Ptgs2, and demonstrated increased expression of Tnf, but also demonstrated a significant reduction in Ccn2 expression. Conclusions: Initial studies of fetal matrices demonstrate promise for muscle regeneration in a rat latissimus dorsi model. Further research is necessary to evaluate fetal matrix for future translational use and better understand its effects.

Preparation and Use of Decellularized Extracellular Matrix for Tissue Engineering

“…In choosing the parameters, selection of the pressure of the vacuum is important. Friedrich E et al (2017) used a vacuum pressure of 508 mmHg (67.7 kPa), in combination with a chemical batch of 0.25% SDS that was agitated at 90–120 rpm, and found that the anecdotally reported decellularization was faster and more efficient [ 146 ], while Wu Young M et al (2020) used similar protocols and achieved effective decellularization [ 118 ]. Butler CR et al (2017) compared vacuum-assisted decellularization with agitation (and lower concentrations of detergents) of the trachea with agitation in a bath of sodium deoxycholate bath under atmospheric pressure and found that, though there was no significant difference in terms of retained bioactive compounds and cell debris between the two methods: the vacuum was more effective at removing cellular material with a substantial reduction in the amount of time to achieve decellularization; there was no difference in mechanical properties of the ECM; cell morphologies in cell culture with the ECM were suggestive of more mature cellular adhesion to the ECM and higher cell survival in vitro ; and there were no significant difference in angiogenesis, biocompatibility, and cellular integration in vivo [ 180 ].…”

“…The ECM can also have other effects on cell culture. The make-up of ECM changes with age, and these differences can affect the behaviour of cells in culture, including ECM from younger animals having the capacity to rejuvenate aged mesenchymal stem cells so that the aged cells regain many of the key properties seen in younger cells, and to alter cell behaviour in injury repair [ 116 , 117 , 118 , 119 , 120 , 121 , 122 ]. The species from which the dECM is derived will also influence the behaviour of cells due to the species-dependent biologic cues intrinsic to the ECM [ 123 ].…”

Decellularized Fetal Matrix Suppresses Fibrotic Gene Expression and Promotes Myogenesis in a Rat Model of Volumetric Muscle Loss

“…W e read the article on accelerated muscle regeneration by fetal rat grafts reported by Wu Young et al 1 with great interest. The authors collected and decellularized composite tissues of the dermis, subcutaneous tissue, and panniculus carnosus from neonatal and fetal rats and fetal rabbits and transplanted them into muscle defects in Sprague-Dawley rats.…”