fibrin and Pseudarthrosis

Tissue engineering appears to be an attractive alternative to the traditional approach in the treatment of fracture non-unions. Mesenchymal stromal cells (MSCs) are considered an appealing cell source for clinical intervention. However, ex vivo cell expansion and differentiation towards the osteogenic lineage, together with the design of a suitable scaffold have yet to be optimized. Major concerns exist about the safety of MSC-based therapies, including possible abnormal overgrowth and potential cancer evolution.. We examined the long-term efficacy and safety of ex vivo expanded bone marrow MSCs, embedded in autologous fibrin clots, for the healing of atrophic pseudarthrosis of the upper limb. Our research work relied on three main issues: use of an entirely autologous context (cells, serum for ex vivo cell culture, scaffold components), reduced ex vivo cell expansion, and short-term MSC osteoinduction before implantation.. Bone marrow MSCs isolated from 8 patients were expanded ex vivo until passage 1 and short-term osteo-differentiated in autologous-based culture conditions. Tissue-engineered constructs designed to embed MSCs in autologous fibrin clots were locally implanted with bone grafts, calibrating their number on the extension of bone damage. Radiographic healing was evaluated with short- and long-term follow-ups (range averages: 6.7 and 76.0 months, respectively). All patients recovered limb function, with no evidence of tissue overgrowth or tumor formation.. Our study indicates that highly autologous treatment can be effective and safe in the long-term healing of bone non-unions. This tissue engineering approach resulted in successful clinical and functional outcomes for all patients.

Topics: Adolescent; Adult; Aged; Compassionate Use Trials; Female; Fibrin; Humans; Male; Mesenchymal Stem Cells; Middle Aged; Prostheses and Implants; Pseudarthrosis; Stem Cell Transplantation; Time Factors; Transplantation, Autologous; Young Adult

Congenital pseudarthrosis of the tibia (CPT) is a rare orthopedic disease presenting spontaneous fractures that do not heal. The treatment of CPT is characterized by repeated surgical procedures that often fail, with the inevitable outcome of severe disability and amputation. We tested the hypothesis that CPT may benefit from regenerative strategies based on mesenchymal stromal cells (MSC) combined with platelet-rich fibrin (PRF) as a source of growth factors. The aim of the study was to verify whether laboratory testing to assess the osteogenic properties of MSC and the osteo-inductive activity of PRF correlated with the clinical outcome.. Ten patients affected by refractory CPT were treated by using MSC derived from the iliac crest (IC-MSC), PRF and lyophilized bone. In six patients, CPT was associated with type 1 neurofibromatosis (NF1). Biochemical, functional and molecular assays were performed to assess the intrinsic osteogenic potential of IC-MSC (cells cultured with fetal calf serum) and the osteo-inductive properties of PRF (cells cultured with autologous serum).. Bone consolidation was obtained in three patients who had CPT and NF1. In these patients, the IC-MSC exposed to autologous serum were able to form mineral nodules in vitro, while the mineralizing ability was totally abrogated in patients with a poor clinical outcome.. Cell therapy may be a useful tool for the treatment of refractory CPT because it increases the opportunity to achieve effective bone tissue regeneration. Our data suggest that the presence of pro-osteogenic growth factors is an essential requirement for bone healing.

Topics: Adolescent; Animals; Bone Regeneration; Cattle; Cell Survival; Cell Transplantation; Cells, Cultured; Child; Child, Preschool; Female; Fibrin; Humans; Ilium; Infant; Male; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Neurofibromatosis 1; Osteogenesis; Pseudarthrosis; Serum; Tibia; Transplantation, Autologous; Treatment Outcome

Animal experiments were carried out on 28 dogs which underwent osteotomy of the femur without postoperative fixation. For systematic light- and transmission electron microscopy tissue from this area of 7 dogs was prepared. Result was a functional morphology of connective tissue. Instability of bone fragments is regarded as the most important factor in pathogenesis of pseudarthrosis. Pathologic mobility in the osteotomy area caused specific altered differentiation of local connective tissue cells, leading to a joint capsule-like formation of connective tissue. "Lining cells" to the pseudarthrotic cavity are fibroblasts and histiocyts, comparable to the "lining cells" of normal stratum synoviale. These cells are surrounded by some collagenous fibres and large amounts of amorphous ground substances. They derive means of numerous transitional forms. The capsule-like tissue formation aside the pseudarthrotic cavity is comparable to stratum synoviale of normal joints. In some of these capsule-like areas there are degenerative alterations similar to those of joint capsules in osteoarthritis.

Topics: Animals; Connective Tissue; Dogs; Femur; Fibrin; Fibroblasts; Histiocytes; Microscopy, Electron; Osteotomy; Pseudarthrosis

Topics: Adolescent; Adult; Animals; Anticoagulants; Blood Coagulation Disorders; Bone Development; Child; Child, Preschool; Female; Fibrin; Fractures, Bone; Fractures, Ununited; Hematoma; Hemophilia A; Heparin; Humans; Infant; Male; Periosteum; Pseudarthrosis; Rabbits; Radiography; Radius Fractures; Warfarin; Wound Healing