A novel, cryopreserved, viable osteochondral allograft designed to augment marrow stimulation for articular cartilage repair.

BACKGROUND: Here, we describe the design and characterization of a novel, cryopreserved, viable osteochondral allograft (CVOCA), along with evidence that the CVOCA can improve outcomes of marrow stimulation for articular cartilage repair. METHODS: Histological staining was performed to evaluate the CVOCA tissue architecture. CVOCAs were tested for the presence of extracellular matrix (ECM) proteins and chondrogenic growth factors using ELISA. Cell viability and composition were examined via live/dead staining, fluorescence-activated cell sorting (FACS) analysis, and immunofluorescence staining. FACS analysis and a TNF-α secretion bioassay were used to confirm the lack of immunogenic cells. Effects of the CVOCA on mesenchymal stem cells (MSCs) were tested using in vitro migration and chondrogenesis assays. The ability of the CVOCA to augment marrow stimulation in vivo was evaluated in a goat model. RESULTS: A method of tissue processing and preservation was developed resulting in a CVOCA with pores and minimal bone. The pores were found to increase the flexibility of the CVOCA and enhance growth factor release. Histological staining revealed that all three zones of hyaline cartilage were preserved within the CVOCA. Chondrogenic growth factors (TGF-ß1, TGF-ß3, BMP-2, BMP-4, BMP-7, bFGF, IGF-1) and ECM proteins (type II collagen, hyaluronan) were retained within the CVOCA, and their sustained release in culture was observed (TGF ß1, TGF-ß2, aggrecan). The cells within the CVOCA were confirmed to be chondrocytes and remained viable and functional post-thaw. Immunogenicity testing confirmed the absence of immunogenic cells. The CVOCA induced MSC migration and chondrogenesis in vitro. Experimental results using devitalized flash frozen osteochondral allografts revealed the importance of preserving all components of articular cartilage in the CVOCA. Goats treated with the CVOCA and marrow stimulation exhibited better repair compared to goats treated with marrow stimulation alone. CONCLUSIONS: The CVOCA retains viable chondrocytes, chondrogenic growth factors, and ECM proteins within the intact architecture of native hyaline cartilage. The CVOCA promotes MSC migration and chondrogenesis following marrow stimulation, improving articular cartilage repair.

Adult human mesenchymal stem cells delivered via intra-articular injection to the knee following partial medial meniscectomy: a randomized, double-blind, controlled study.

BACKGROUND: There are limited treatment options for tissue restoration and the prevention of degenerative changes in the knee. Stem cells have been a focus of intense preclinical research into tissue regeneration but limited clinical investigation. In a randomized, double-blind, controlled study, the safety of the intra-articular injection of human mesenchymal stem cells into the knee, the ability of mesenchymal stem cells to promote meniscus regeneration following partial meniscectomy, and the effects of mesenchymal stem cells on osteoarthritic changes in the knee were investigated. METHODS: A total of fifty-five patients at seven institutions underwent a partial medial meniscectomy. A single superolateral knee injection was given within seven to ten days after the meniscectomy. Patients were randomized to one of three treatment groups: Group A, in which patients received an injection of 50 × 106 allogeneic mesenchymal stem cells; Group B, 150 × 106 allogeneic mesenchymal stem cells; and the control group, a sodium hyaluronate (hyaluronic acid/hyaluronan) vehicle control. Patients were followed to evaluate safety, meniscus regeneration, the overall condition of the knee joint, and clinical outcomes at intervals through two years. Evaluations included sequential magnetic resonance imaging (MRI). RESULTS: No ectopic tissue formation or clinically important safety issues were identified. There was significantly increased meniscal volume (defined a priori as a 15% threshold) determined by quantitative MRI in 24% of patients in Group A and 6% in Group B at twelve months post meniscectomy (p = 0.022). No patients in the control group met the 15% threshold for increased meniscal volume. Patients with osteoarthritic changes who received mesenchymal stem cells experienced a significant reduction in pain compared with those who received the control, on the basis of visual analog scale assessments. CONCLUSIONS: There was evidence of meniscus regeneration and improvement in knee pain following treatment with allogeneic human mesenchymal stem cells. These results support the study of human mesenchymal stem cells for the apparent knee-tissue regeneration and protective effects.

A placebo-controlled, randomized trial of mesenchymal stem cells in COPD.

BACKGROUND: COPD is a devastating disease affecting millions worldwide. As disease pathogenesis includes both chronic pulmonary and systemic inflammation, antiinflammatory effects of systemically administered mesenchymal stem cells (MSCs) may decrease inflammation, resulting in improved lung function and quality of life. The goal of this study was to assess safety and to perform an initial evaluation of the potential efficacy of systemic MSC administration to patients with moderate to severe COPD. METHODS: Sixty-two patients at six sites were randomized to double-blinded IV infusions of either allogeneic MSCs (Prochymal; Osiris Therapeutics Inc) or vehicle control. Patients received four monthly infusions (100 × 106 cells/infusion) and were subsequently followed for 2 years after the first infusion. End points included comprehensive safety evaluation, pulmonary function testing (PFT), and quality-of-life indicators including questionnaires, 6MWT, and assessments of systemic inflammation. RESULTS: All study patients completed the full infusion protocol, and 74% completed the 2-year follow-up. There were no infusional toxicities and no deaths or serious adverse events deemed related to MSC administration. There were no significant differences in the overall number of adverse events, frequency of COPD exacerbations, or worsening of disease in patients treated with MSCs. There were no significant differences in PFTs or quality-of-life indicators; however, an early, significant decrease in levels of circulating C-reactive protein (CRP) was observed in patients treated with MSCs who had elevated CRP levels at study entry. CONCLUSIONS: Systemic MSC administration appears to be safe in patients with moderate to severe COPD and provides a basis for subsequent cell therapy investigations. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT00683722; URL: www.clinicaltrials.gov.