Effects of Adipose-Derived Stem Cells and Their Conditioned Medium in a Human Ex Vivo Wound Model

Abstract

Adult stem cells have been extensively investigated for tissue repair therapies. Adipose-derived stem cells (ASCs) were shown to improve wound healing by promoting re-epithelialization and vascularization as well as modulating the inflammatory immune response. In this study, we used ex vivo human skin cultured in a six-well plate with trans-well inserts as a model for superficial wounds. Standardized wounds were created and treated with allogeneic ASCs, ASCs conditioned medium (ASC-CM), or cell culture medium (DMEM) supplemented with fetal calf serum (FCS). Skin viability (XTT test), histology (hematoxylin and eosin, H and E), β-catenin expression as well as inflammatory mediators and growth factors were monitored over 12 days of skin culture. We observed only a moderate time-dependent decrease in skin metabolic activity while skin morphology was preserved, and re-epithelialization occurred at the wound edges. An increase in β-catenin expression was observed in the newly formed epithelia, especially in the samples treated with ASC-CM. In general, increased growth factors and inflammatory mediators, e.g., hepatocytes growth factor (HGF), platelet-derived growth factor subunit AA (PDGF-AA), IL-1α, IL-7, TNF-α, and IL-10, were observed over the incubation time. Interestingly, different expression profiles were observed for the different treatments. Samples treated with ASC-CM significantly increased the levels of inflammatory cytokines and PDGF-AA with respect to control, whereas the treatment with ASCs in DMEM with 10% FCS resulted in significantly increased levels of fibroblast growth factor-basic (FGF-basic) and moderate increases of immunomodulatory cytokines. These results confirm that the wound microenvironment can influence the type of mediators secreted by ASCs and the mode as to how they improve the wound healing process. Comparative investigations with pre-activated ASCs will elucidate further aspects of the wound healing mechanism and improve the protocols of ACS application.

Cell secretomes for wound healing and tissue regeneration: Next generation acellular based tissue engineered products

“…8 Another alternative to get the secretomes is by using the human adipose-derived stem cells (ADSC) due to the ease of access in human tissue and the great potential of secretory proteins in stem cell therapy. [90][91][92] ADSC-CM is good for wound healing therapy because it contains growth factors and cytokines vital to wound healing by promoting granulation and vascularization and enhancing macrophage recruitment. 93 The growth factors include FGF, TGF-β1, and PDGF, which promote ECM synthesis, deposition, and organization of collagen and fibronectin besides contributing to cell signaling and tissue remodeling.…”

Towards Regenerative Audiology: Immune Modulation of Adipose-Derived Mesenchymal Cells Preconditioned with Citric Acid-Coated Antioxidant-Functionalized Magnetic Nanoparticles

“…However, the complexity of producing and marketing products that are based on living cells in terms of manufacturing, costs and ethical and regulatory approval has consistently impaired their advancement to clinical settings. Serum-free conditioned media (CM) from ADSCs has been sought out as a modality to avoid the hurdles involved in the therapeutic delivery of living cells [ 23 ]. CM from ADSCs preconditioned with various molecules has proven efficient in rescuing hair cell loss due to paracrine regenerative and immunomodulatory activity [ 24 ].…”

Smoking Suppresses the Therapeutic Potential of Adipose Stem Cells in Crohn’s Disease Patients through Epigenetic Changes

“…Intriguingly, genes with different methylation patterns in smoker patients (present and past) were involved in relevant biological processes such as wound healing, osteoblast differentiation, T-cell differentiation, extracellular matrix organization and response to transforming growth factor beta, which are all crucial to ameliorate inflammation and regenerate damaged tissue. Interestingly, TGFB is only expressed in mammals and mainly secreted and stored as a latent complex in the extracellular matrix [ 39 ]. More importantly, its activation is necessary to recruit stem cells in order to participate in the tissue regeneration and remodeling process [ 40 ].…”