Designing 3D Mesenchymal Stem Cell Sheets Merging Magnetic and Fluorescent Features: When Cell Sheet Technology Meets Image-Guided Cell Therapy

Abstract

Cell sheet technology opens new perspectives in tissue regeneration therapy by providing readily implantable, scaffold-free 3D tissue constructs. Many studies have focused on the therapeutic effects of cell sheet implantation while relatively little attention has concerned the fate of the implanted cells in vivo. The aim of the present study was to track longitudinally the cells implanted in the cell sheets in vivo in target tissues. To this end we (i) endowed bone marrow-derived mesenchymal stem cells (BMMSCs) with imaging properties by double labeling with fluorescent and magnetic tracers, (ii) applied BMMSC cell sheets to a digestive fistula model in mice, (iii) tracked the BMMSC fate in vivo by MRI and probe-based confocal laser endomicroscopy (pCLE), and (iv) quantified healing of the fistula. We show that image-guided longitudinal follow-up can document both the fate of the cell sheet-derived BMMSCs and their healing capacity. Moreover, our theranostic approach informs on the mechanism of action, either directly by integration of cell sheet-derived BMMSCs into the host tissue or indirectly through the release of signaling molecules in the host tissue. Multimodal imaging and clinical evaluation converged to attest that cell sheet grafting resulted in minimal clinical inflammation, improved fistula healing, reduced tissue fibrosis and enhanced microvasculature density. At the molecular level, cell sheet transplantation induced an increase in the expression of anti-inflammatory cytokines (TGF-ß2 and IL-10) and host intestinal growth factors involved in tissue repair (EGF and VEGF). Multimodal imaging is useful for tracking cell sheets and for noninvasive follow-up of their regenerative properties.

Mesenchymal stem cells and extracellular matrix scaffold promote muscle regeneration by synergistically regulating macrophage polarization toward the M2 phenotype

“…Recent studies showed that the ECM secreted by MSCs could be the bridge to connect the cells and it can make MSCs easier to stay in place where they need to function. In addition, they can create the microenvironment to maintain homeostasis and they also can enhance the survival capacity of MSCs effectively [ 62 , 63 ]. Meanwhile, the decellularized ECM mainly focuses on the recruitment of endogenous stem cells and immune cells to rebuild the destroyed microenvironment [ 33 , 64 ].…”

A Concise Review on the Use of Mesenchymal Stem Cells in Cell Sheet-Based Tissue Engineering with Special Emphasis on Bone Tissue Regeneration

“…Within the last two decades, cell sheets of MSCs have been used in tissue engineering/tissue regeneration of several types of tissues and/or organs including (but are not limited to) the cornea [ 39 ], skin [ 40 , 41 ], cartilage [ 42 , 43 ], meniscus [ 44 ], bone [ 31 , 45 – 53 ], tendons [ 53 ], cardiac tissue [ 54 – 62 ], periodontal tissue [ 63 , 64 ], nasal epithelium [ 65 ], tooth [ 66 ], and blood vessel [ 67 ]. Cell sheets of MSCs have also been used in conditions such as wound healing [ 41 ], oral ulcers [ 68 ], digestive fistula [ 69 ], and spinal cord defects [ 70 , 71 ]. It has also been demonstrated that MSC sheets can induce angiogenesis in ischemic and/or wound tissues [ 41 , 72 ].…”

Composite cell sheet for periodontal regeneration: crosstalk between different types of MSCs in cell sheet facilitates complex periodontal-like tissue regeneration

“…Recent studies on exosomes [56] and Gabriel Rahmi’s latest study [57] revealed that although most of the implanted cells would die in a few days, they could be involved in tissue repair through the paracrine effect, which offer us some insights regarding future investigations. In addition, clinical periodontal tissue defects normally are accompanied by inflammation, whether the composite can properly function in this microenvironment remains unknown.…”