Wivine André

Human Adipose-Derived Mesenchymal Stem Cells in Cell Therapy: Safety and Feasibility in Different "Hospital Exemption" Clinical Applications

Based on immunomodulatory, osteogenic, and pro-angiogenic properties of adipose-derived stem cells (ASCs), this study aims to assess the safety and efficacy of ASC-derived cell therapies for clinical indications. Two autologous ASC-derived products were proposed to 17 patients who had not experienced any success with conventional therapies: (1) a scaffold-free osteogenic three-dimensional graft for the treatment of bone non-union and (2) a biological dressing for dermal reconstruction of non-healing chronic wounds. Safety was studied using the quality control of the final product (genetic stability, microbiological/mycoplasma/endotoxin contamination) and the in vivo evaluation of adverse events after transplantation. Feasibility was assessed by the ability to reproducibly obtain the final ASC-based product with specific characteristics, the time necessary for graft manufacturing, the capacity to produce enough material to treat the lesion, the surgical handling of the graft, and the ability to manufacture the graft in line with hospital exemption regulations. For 16 patients (one patient did not undergo grafting because of spontaneous bone healing), in-process controls found no microbiological/mycoplasma/endotoxin contamination, no obvious deleterious genomic anomalies, and optimal ASC purity. Each type of graft was reproducibly obtained without significant delay for implantation and surgical handling was always according to the surgical procedure and the implantation site. No serious adverse events were noted for up to 54 months. We demonstrated that autologous ASC transplantation can be considered a safe and feasible therapy tool for extreme clinical indications of ASC properties and physiopathology of disease.

Autologous Adipose Stromal Cells Seeded onto a Human Collagen Matrix for Dermal Regeneration in Chronic Wounds: Clinical Proof of Concept.

Background: Nonhealing wounds are unable to integrate skin autografts by avascular and fibrotic dermal tissue. Adipose-derived stromal cells can improve the local environment of the wound bed by angiogenesis and immunomodulation. This work aimed to develop a biological dressing made of adipose-derived stromal cells onto a human acellular collagen matrix. Methods: Adipose-derived stromal cells were isolated from human adipose tissue (n = 8). In vitro, the genetic stability during early and late passages (1, 4, 10, and 16) and vascular endothelial growth factor (VEGF) secretion were assessed. Adipose-derived stromal cell adhesion and spreading on collagen matrix were preliminarily studied. In vivo tumorigenicity, angiogenesis, and tissue oxygenation were assessed after implantation of the construct in nude rats (n = 10). The biological dressing was manufactured and implanted in three patients with chronic wounds. Results: In vitro, aneuploidies, but no clonal transformation, were detected up to late cellular passages. VEGF was secreted more during hypoxia (0.1% oxygen) than during normoxia (21% oxygen). Adipose-derived stromal cells can adhere and spread on the scaffold within 18 to 20 days. No tumor development occurred 3 months after implantation in immunocompromised rats. Vessel counts and tissue oxygenation were higher after adipose-derived stromal cell implantation. In patients, granulation tissue was found (276 percent of vessel density), followed by epithelialization or split-thickness skin engraftment up to 22 months after implantation. Conclusions: Implantation of adipose-derived stromal cells seeded onto human acellular collagen matrix (biological dressing) represents a promising therapy for nonhealing wounds, offering improvement in dermal angiogenesis and remodeling. This therapy using autologous stromal cells is safe, without significant genetic alterations after in vitro expansion.

Scaffold-free Three-dimensional Graft From Autologous Adipose-derived Stem Cells for Large Bone Defect Reconstruction: Clinical Proof of Concept.

AbstractLong bone nonunion in the context of congenital pseudarthrosis or carcinologic resection (with intercalary bone allograft implantation) is one of the most challenging pathologies in pediatric orthopedics. Autologous cancellous bone remains the gold standard in this context of long bone nonunion reconstruction, but with several clinical limitations. We then assessed the feasibility and safety of human autologous scaffold-free osteogenic 3-dimensional (3D) graft (derived from autologous adipose-derived stem cells [ASCs]) to cure a bone nonunion in extreme clinical and pathophysiological conditions.Human ASCs (obtained from subcutaneous adipose tissue of 6 patients and expanded up to passage 4) were incubated in osteogenic media and supplemented with demineralized bone matrix to obtain the scaffold-free 3D osteogenic structure as confirmed in vitro by histomorphometry for osteogenesis and mineralization. The 3D “bone-like” structure was finally transplanted for 3 patients with bone tumor and 3 patients with bone pseudarthrosis (2 congenital, 1 acquired) to assess the clinical feasibility, safety, and efficacy. Although minor clones with structural aberrations (aneuploidies, such as tri or tetraploidies or clonal trisomy 7 in 6%–20% of cells) were detected in the undifferentiated ASCs at passage 4, the osteogenic differentiation significantly reduced these clonal anomalies. The final osteogenic product was stable, did not rupture with forceps manipulation, did not induce donor site morbidity, and was easily implanted directly into the bone defect. No acute (<3 mo) side effects, such as impaired wound healing, pain, inflammatory reaction, and infection, or long-term side effects, such as tumor development, were associated with the graft up to 4 years after transplantation.We report for the first time that autologous ASC can be fully differentiated into a 3D osteogenic-like implant without any scaffold. We demonstrated that this engineered tissue can safely promote osteogenesis in extreme conditions of bone nonunions with minor donor site morbidity and no oncological side effects.