Objectives. Interleukin 18 (IL-18) is a regulatory cytokine that degrades the disc matrix.
We investigated the rates of expression of
In the treatment of bone non-unions an alternative to bone autografts is the use of bone morphogenetic proteins (BMP-2, BMP-7) with powerful osteoinductive and osteogenic properties. In clinical settings, BMPs are applied using absorbable collagen sponges. Supraphysiological doses are needed and major side effects may occur as induce ectopic bone formation, chronic inflammation and excessive bone resorption. In order to increase the efficiency of the delivered for BMPs we designed cryostructured collagen scaffolds functionalized with hydroxyapatite, mimicking the structure of cortical bone (aligned porosity, anisotropic, ANI) or trabecular bone (random distributed porosity, isotropic, ISO). We hypothesize that anisotropic structure would enhance osteoconductive properties of the scaffolds increasing rhBMP-2 regenerative properties.
Sustained release of BMP-2 is reported to be able to reduce the required dose of BMP-2 for bone induction. Nanohydroxyapatite (nHAp) has an osteoinduction capability which is lack in conventional hydroxyapatite. In this study, we combined PLA-PEG with nHAp and investigated the bone regenerative capacity of the newly established composite material of rhBMP-2/PLA-PEG/nHAp in a rat model of spinal fusion. The PLA-PEG was liquidized in acetone and mixed with nHAp and rhBMP-2. The sheet-shaped BMP-2/PLA-PEG (5mg)/nHAp (12.5mg) composites were prepared while evaporating the acetone. The release kinetics of rhBMP-2 from the composite was investigated by ELISA.
While new biomaterials for regenerative therapies are being reported in the literature, clinical translation is slow. Existing regenerative approaches rely on high doses of growth factors, such as BMP-2 in bone regeneration, which can cause serious side effects. We describe an ultra-low-dose growth factor technology yielding high bioactivity based on a simple polymer, poly (ethyl acrylate) (PEA), and report its translation to a clinical veterinary setting. This polymer-based technology triggers spontaneous fibronectin organization and stimulates growth factor signaling, enabling synergistic integrin and BMP-2 receptor activation in mesenchymal stem cells. To translate this technology, we use plasma-polymerized PEA on 2D and 3D substrates to enhance cell signaling
We have examined whether primary human muscle-derived cells can be used in ex vivo gene therapy to deliver BMP-2 and to produce bone in vivo. Two in vitro experiments and one in vivo experiment were used to determine the osteocompetence and BMP-2 secretion capacity of cells isolated from human skeletal muscle. We isolated five different populations of primary muscle cells from human skeletal muscle in three patients. In the first in vitro experiment, production of alkaline phosphatase by the cells in response to stimulation by rhBMP-2 was measured and used as an indicator of cellular osteocompetence. In the second, secretion of BMP-2 was measured after the cell populations had been transduced by an adenovirus encoding for BMP-2. In the in vivo experiment, the cells were cotransduced with a retrovirus encoding for a nuclear localised β-galactosidase gene and an adenovirus encoding for BMP-2. The cotransduced cells were then injected into the hind limbs of severe combined immune-deficient (SCID) mice and analysed radiographically and histologically. The nuclear localised β-galactosidase gene allowed identification of the injected cells in histological specimens. In the first in vitro experiment, the five different cell populations all responded to in vitro stimulation of rhBMP-2 by producing higher levels of alkaline phosphatase when compared with non-stimulated cells. In the second, the five different cell populations were all successfully transduced by an adenovirus to express and secrete BMP-2. The cells secreted between 444 and 2551 ng of BMP-2 over three days. In the in vivo experiment, injection of the transduced cells into the hind-limb musculature of SCID mice resulted in the formation of ectopic bone at 1, 2, 3 and 4 weeks after injection. Retroviral labelling of the cell nuclei showed labelled human muscle-derived cells occupying locations of osteoblasts in the ectopic bone, further supporting their osteocompetence. Cells from human skeletal muscle, because of their availability to orthopaedic surgeons, their osteocompetence, and their ability to express BMP-2 after genetic engineering, are an attractive cell population for use in BMP-2 gene therapy approaches.
The objective of this study was to investigate the effects of different doses rhBMP-2 on bone healing in an ovine lumbar interbody fusion model. In this study 22 sheep underwent two level lumbar interbody fusion using a ventrolateral approach with secondary dorsal fixation at L1/2 and L3/4. After randomization in one level a PEEK-cage was implanted filled with one of three doses rhBMP-2 (0,5mg; 1mg; 2mg) delivered on an ACS. The other level received an empty PEEK-cage or ACS filled cage. Animals were sacrificed after 3 and 6 months and decalcified histology was performed. This included histomorphological analysis well as histomorphometry of the tissues within the cage. At 3 months after surgery the groups treated with rhBMP-2 showed higher amounts of bone tissue within the cage. At 6 months the amounts of bone tissue increased in all groups, were still lower in the groups without growth factor. At 3 months there was only one active osteolysis in the cage/ACS. 7 of 8 segments of the rhBMP-2 groups had a compromised bone structure around the implant. These areas were filled with fibrous tissue and fibrocartilage. This finding was not detected in the groups without rhBMP-2 at 3 months. At 6 months most of the segments with an empty cage or cage/ACS showed a chronic inflammation. Predominant cells were macrophages and giant cells. The groups treated with rhBMP-2 showed only a few mild chronic inflammatory reactions. The well-known dose dependent effect of rhBMP-2 on bone healing could also be recognized in our study. Attention has to be payed to the proinflammatory properties of the growth factor. Consistent with other studies we found 2 strong inflammatory reactions, each one in the lowest and highest dose group. Also, the potential for causing transient bone resorptions, according to the results of others, was demonstrated. At 3 months 7 of 8 segments treated with rhBMP-2 showed compromised peri-implant bone. Osteoblasts, but not osteoclasts, were seen in the periphery of these areas. It can be concluded that there where bone resorptions which already merged into an increased osteoblastic activity. Usually resorptions occur between 2 and 12 weeks and are followed by a period of increased osteoblastic activity. This finding wasn't recognized at 6 months anymore. Striking is that at 6 months most of the segments without rhBMP-2 showed a compromised bone structure around the implant with a mild to mainly moderate chronic inflammatory reaction. This cannot be attributed to the growth factor. Also, the ACS is degraded at 6 months and is unlikely a possible explanation. Therefore, the cage as a reason must be considered and it has to be questioned whether PEEK is the optimal material for interbody cages.
Various approaches have been implemented to enhance bone regeneration, including the utilization of autologous platelet-rich plasma and
Introduction. To develop an international guideline (AOGO) about use of osteobiologics in Anterior Cervical Discectomy and Fusion (ACDF) for treating degenerative spine conditions. Method. The guideline development process was guided by AO Spine Knowledge Forum Degenerative (KF Degen) and followed the Guideline International Network McMaster Guideline Development Checklist. The process involved 73 participants with expertise in degenerative spine diseases and surgery from 22 countries. Fifteen systematic reviews were conducted addressing respective key topics and evidence were collected. The methodologist compiled the evidence into GRADE Evidence-to-Decision frameworks. Guideline panel members judged the outcomes and other criteria and made the final recommendations through consensus. Result. Five conditional recommendations were created. A conditional recommendation is about the use of allograft, autograft or a cage with an osteobiologic in primary ACDF surgery. Other conditional recommendations are about use of osteobiologic for single or multi-level ACDF, and for hybrid construct surgery. It is suggested that surgeons use other osteobiologics rather than human
The efficacy of β-tricalcium phosphate (β-TCP) loaded with
Introduction. Bioactive glasses (BGs) promote osteogenic differentiation of bone progenitor cells by releasing therapeutically active ions. The well-described 45S5-BG (in mol%: SiO. 2. 46.13; P. 2. O. 5. 2.60; CaO 26.91; Na. 2. O 24.35) was supplemented with CaF. 2. and NaF being added to the batch at nominal 5 (F5-BG) and 25 mol% (F25-BG), respectively. While the effect on physical and chemical properties has already been characterized, the biological properties require further studies. This study investigates the effects of fluoride-supplemented BGs on the osteogenic and angiogenic properties of human bone marrow mesenchymal stromal cells (BMSCs) in vitro. Method. BMSCs were co-cultured with melt-derived 45S5-BG, F5-BG, or F25-BG in ascending concentrations (1, 2 and 3 mg/ml). At 7 days, cell number was determined by 4,6-diamidine-2-phenylindole (DAPI) staining and cell viability by fluorescein diacetate (FDA) assay. The osteogenic potential of the BGs was evaluated through alkaline phosphatase (ALP) gene expression and activity, along with
Design criteria for tissue-engineered materials in regenerative medicine include robust biological effectiveness, off-the-shelf availability, and scalable manufacturing under standardized conditions. For bone repair, existing strategies rely on primary autologous cells, associated with unpredictable performance, limited availability and complex logistic. Here, we report the manufacturing of engineered and devitalized human hypertrophic cartilage (HyC) as cell-free material inducing bone formation by recapitulating the developmental process of endochondral ossification. Our strategy relies on a customized human mesenchymal line expressing
The feasibility of bone transport with bone substitute and the factors which are essential for a successful bone transport are unknown. We studied six groups of 12 Japanese white rabbits. Groups A to D received cylindrical autologous bone segments and groups E and F hydroxyapatite prostheses. The periosteum was preserved in group A so that its segments had a blood supply, cells, proteins and scaffold. Group B had no blood supply. Group C had proteins and scaffold and group D had only scaffold. Group E received hydroxyapatite loaded with recombinant human
Introduction and Objective. Several in vitro studies have shed light on the osteogenic and chondrogenic potential of graphene and its derivatives. Now it is possible to combine the different biomaterial properties of graphene and 3D printing scaffolds produced by tissue engineering for cartilage repair. Owing to the limited repair capacity of articular cartilage and bone, it is essential to develop tissue-engineered scaffolds for patients suffering from joint disease and trauma. However, chondral lesions cannot be considered independently of the underlying bone tissue. Both the microcirculation and the mechanical support provided with bone tissue must be repaired. One of the distinctive features that distinguish graphene from other nanomaterials is that it can have an inductive effect on both bone and cartilage tissue. In this study, the effect of different concentrations of graphene on the in vivo performance of single-layer poly-ε-caprolactone based-scaffolds is examined. Our hypothesis is that graphene nanoplatelet- containing, robocast PCL scaffolds can be an effective treatment option for large osteochondral defect treatment. For this purpose, different proportions of graphene- containing (1%,3%,5%,10 wt%) PCL scaffolds were studied in a 5mm diameter osteochondral defect model created in the rabbit knee. Materials and Methods. In the study graphene-containing (1, 3, 5, 10 wt%), porous and oriented poly-ε-caprolactone-based scaffolds were prepared by robocasting method to use in the regeneration of large osteochondral defects. Methods: The scaffolds were implanted into the full-thickness osteochondral defect in a rabbit model to evaluate the regeneration of defect in vivo. For this purpose, twenty female New Zealand white rabbits were used and they were euthanized at 4 and 8 weeks of implantation. The reparative osteochondral tissues were harvested from rabbit distal femurs and then processed for gross appearance assessment, radiographic imaging, histopathological and immunohistochemical examinations. Results. Results revealed that, graphene- containing graft materials caused significant amelioration at the defect areas. Graphene-containing graft materials improved the fibrous, chondroid and osseous tissue regeneration compared to the control group. The expressions of
The management of bone defects and impaired fracture healing remains one of the most challenging clinical problems. Several treatments exist to aid in the healing of large bone defects, including biologics such as recombinant human
In therapeutic bone repairs, autologous bone grafts, conventional or vascularized allografts, and biocompatible artificial bone substitutes all have their shortcomings. Tissue engineering may be an alternative for cranial bone repair. Titanium (Ti) and its alloys are widely used in many clinical devices because of perfect biocompatibility, highly corrosion resistance and ideal physical properties. An important progress in treating bone defects has been the introduction of bone morphogenetic proteins (BMPs), specifically BMP-2. The proteins induce osteogenic cell differentiation in vitro, as well as bone defect healing in vivo. In this study, we fabricated the titanium plate with dioxide creating by microarc oxidation (MAO) and then electronic deposition of Ca.P that can carrier recombinant human
As we grow older, the risk of tendon degeneration and injuries increases, which can result in pain, disability, healthcare cost, and lost productivity. Even after surgical repair the results are often unsatisfactory. The cellular reasons for the differences in the healing potential, however, are not well studied. To get a deeper insight into the biological characteristics of tenocyte-like cells from different patient groups we established a biobank with material from over 150 human donors. The patients/donors suffered from rotator cuff tears and were operated to restore the function. A proportion of the isolated cells showed stem cell-like characteristics and was able to differentiate into the osteoblastic, chondrogenic and adipogenic linage. Investigating the differentiation potential of the cells with regard to donor characteristics, we were able to demonstrate that age, sex but also the “degeneration” has an impact of the cellular potential. A possibility to stimulate the cellular activity is the application of growth factors, as already clinically used for stimulation of bone healing. Therefore, the responsiveness of the cells to the growth factors
Objectives. We have observed clinical cases where bone is formed in the overlaying muscle covering surgically created bone defects treated with a hydroxyapatite/calcium sulphate biomaterial. Our objective was to investigate the osteoinductive potential of the biomaterial and to determine if growth factors secreted from local bone cells induce osteoblastic differentiation of muscle cells. Materials and Methods. We seeded mouse skeletal muscle cells C2C12 on the hydroxyapatite/calcium sulphate biomaterial and the phenotype of the cells was analysed. To mimic surgical conditions with leakage of extra cellular matrix (ECM) proteins and growth factors, we cultured rat bone cells ROS 17/2.8 in a bioreactor and harvested the secreted proteins. The secretome was added to rat muscle cells L6. The phenotype of the muscle cells after treatment with the media was assessed using immunostaining and light microscopy. Results. C2C12 cells differentiated into osteoblast-like cells expressing prominent bone markers after seeding on the biomaterial. The conditioned media of the ROS 17/2.8 contained
Multipotential processed lipoaspirate (PLA) cells extracted from five human infrapatellar fat pads and embedded into fibrin glue nodules, were induced into the chondrogenic phenotype using chondrogenic media. The remaining cells were placed in osteogenic media and were transfected with an adenovirus carrying the cDNA for
Bone morphogenetic protein (BMP) has a crucial role in osteochondrogenesis of bone formation as well as in the repair of fractures. The interaction between hedgehog protein and BMPs is inferred from recent molecular studies. Hedgehog genes encode secreted proteins which mediate patterning and growth during skeletal development. We have shown that Indian hedgehog gene (Ihh) is expressed in cartilage anlage and later in mature and hypertrophic chondrocytes. This finding suggests that Ihh may regulate the development of chondrocytes. Our results in this study have shown that Ihh transcripts were expressed in hypertrophic chondrocytes in mice at three days but not at three weeks, although a similar expression pattern of α1 (X) collagen could be observed in both types of cartilage. To investigate the possibility that there are direct and age-dependent functions of Ihh in chondrocytes, cultured chondrocytes were treated with the amino-terminal fragment of Sonic hedgehog protein (Shh-N) which can functionally substitute for Ihh protein. Shh-N did not affect the proliferation and differentiation of chondrocytes from three-week-old mice but had a significant effect on three-day-old mice. It enhanced proliferation up to 128% of the control culture in a dose-dependent manner. Although there was no effect in Shh-N-treated cultures, Shh-N enhanced the stimulatory effect of parathyroid hormone (PTH) on the synthesis of proteoglycans. Because the effects of Shh-N on chondrocyte differentiation in this culture system differed from those of
