Asynchronous calibration of a CT scanner for bone mineral density estimation: sources of error and correction.

The estimation of BMD with CT scans requires a calibration method, usually based on a phantom. In asynchronous calibration, the phantom is scanned separately from the patient. A standardized acquisition protocol must be used to avoid variations between patient and phantom.

Exogenous Stimulation of Human Intervertebral Disc Cells in 3-Dimensional Alginate Bead Culture With BMP2 and L51P: Cytocompatibility and Effects on Cell Phenotype.

Objective: Spinal fusion surgery is a common treatment modality for various pathologic conditions of the spine. The bone morphogenetic protein 2 (BMP2) analogue L51P acts as a general inhibitor of BMP antagonists, whereas it shows a weak affinity for BMP type I receptor. It is suggested that L51P applied in bone disorders might prevent side effects of highly concentrated BMP dosage applications in the order of milligrams.

Application of Cytokines of the Bone Morphogenetic Protein (BMP) Family in Spinal Fusion - Effects on the Bone, Intervertebral Disc and Mesenchymal Stromal Cells.

Low back pain is a prevalent socio-economic burden and is often associated with damaged or degenerated intervertebral discs (IVDs). When conservative therapy fails, removal of the IVD (discectomy), followed by intersomatic spinal fusion, is currently the standard practice in clinics. The remaining space is filled with an intersomatic device (cage) and with bone substitutes to achieve disc height compensation and bone fusion.

Fluorescence-Activated Cell Sorting Is More Potent to Fish Intervertebral Disk Progenitor Cells Than Magnetic and Beads-Based Methods.

Low back pain related to intervertebral disk (IVD) degeneration has a major socioeconomic impact on our aging society. Therefore, stem cell therapy to activate self-repair of the IVD remains an exciting treatment strategy. In this respect, tissue-specific progenitors may play a crucial role in IVD regeneration, as these cells are perfectly adapted to this niche.

Successful fishing for nucleus pulposus progenitor cells of the intervertebral disc across species.

Background: Recently, Tie2/TEK receptor tyrosine kinase (Tie2 or syn. angiopoietin-1 receptor) positive nucleus pulposus progenitor cells were detected in human, cattle, and mouse. These cells show remarkable multilineage differentiation capacity and direct correlation with intervertebral disc (IVD) degeneration and are therefore an interesting target for regenerative strategies.

Genipin-Enhanced Fibrin Hydrogel and Novel Silk for Intervertebral Disc Repair in a Loaded Bovine Organ Culture Model.

(1) Background: Intervertebral disc (IVD) repair represents a major challenge. Using functionalised biomaterials such as silk combined with enforced hydrogels might be a promising approach for disc repair. We aimed to test an IVD repair approach by combining a genipin-enhanced fibrin hydrogel with an engineered silk scaffold under complex load, after inducing an injury in a bovine whole organ IVD culture; (2) Methods: Bovine coccygeal IVDs were isolated from ~1-year-old animals within four hours post-mortem.

Intervertebral disc damage models in organ culture: a comparison of annulus fibrosus cross-incision versus punch model under complex loading.

Purpose: Comparison of two annulus fibrosus injury models that mimic intervertebral disc (IVD) herniation, enabling the study of IVD behaviour under three loading regimes in a bovine organ culture model.

Methods: An injury was induced by custom-designed cross-incision tool or a 2-mm biopsy punch in IVDs. Discs were cultured for 14 days under (1) complex (compression and torsion), (2) static, and (3) no load.

Inhibitory Effects of Human Primary Intervertebral Disc Cells on Human Primary Osteoblasts in a Co-Culture System.

Spinal fusion is a common surgical procedure to address a range of spinal pathologies, like damaged or degenerated discs. After the removal of the intervertebral disc (IVD), a structural spacer is positioned followed by internal fixation, and fusion of the degenerated segment by natural bone growth. Due to their osteoinductive properties, bone morphogenetic proteins (BMP) are applied to promote spinal fusion.

Differentiation of MSC and annulus fibrosus cells on genetically engineered silk fleece-membrane-composites enriched for GDF-6 or TGF-β3.

Intervertebral disc (IVD) repair is a high-priority topic in our active and increasingly ageing society. Since a high number of people are affected by low back pain treatment options that are able to restore the biological function of the IVD are highly warranted. Here, we investigated whether the feasibility of genetically engineered (GE)-silk from Bombyx mori containing specific growth factors to precondition human bone-marrow derived mesenchymal stem cells (hMSC) or to activate differentiated human annulus fibrosus cells (hAFC) prior transplantation or for direct repair on the IVD.

Biologic response of human anterior cruciate ligamentocytes on collagen-patches to platelet-rich plasma formulations with and without leucocytes.

Due to the poor self-healing capacities of the anterior cruciate ligament, previous primary repair attempts have failed. To enhance biologic healing, platelet rich plasma and collagen scaffold have shown promise in animal models. Platelet rich plasma (PRP) is already used in several clinical applications although outcomes are quite debated.

Efficient Nonviral Transfection of Primary Intervertebral Disc Cells by Electroporation for Tissue Engineering Application.

Low back pain (LBP) is an increasing global health problem associated with intervertebral disc (IVD) trauma and degeneration. Current treatment options include surgical interventions with partial unsatisfactory outcomes reported such as failure to relieve LBP, nonunions, nerve injuries, or adjacent segment disease. Cell-based therapy and tissue engineered IVD constructs supplemented with transfected disc cells that incorporate factors enhancing matrix synthesis represent an appealing approach to regenerate the IVD.

A photopolymerized composite hydrogel and surgical implanting tool for a nucleus pulposus replacement.

Nucleus pulposus replacements have been subjected to highly controversial discussions over the last 40 years. Their use has not yet resulted in a positive outcome to treat herniated disc or degenerated disc disease. The main reason is that not a single implant or tissue replacement was able to withstand the loads within an intervertebral disc.