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Osteoblasts Secrete Pro-Inflammatory Cytokines on PEEK but Anti-inflammatory Cytokines on Microstructured Titanium
Proceedings of the NASS 29th Annual Meeting / The Spine Journal 14 (2014) 1S–183S inflammation (CD-68) and astrocyte density (GFAP and neurofilament) are being performed. CONCLUSIONS: The results provide a rationale for further investigations into the potential neuroprotective effects of intrathecal MP in SCI. Further investigations in different models with increased sample size are necessary to evaluate the neuroprotective effect of IT MP in SCI. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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(Olivares-Navarrete et al., Spine J, 2012). Those findings, combined with the current results, suggest that fibrous tissue around the surface of PEEK implants is due to several factors: reduced osteoblastic differentiation of progenitor cells and production of an inhibitory inflammatory environment that favors cell death via apoptosis and necrosis. However, titanium alloy surfaces with complex micron scale and submicron scale roughness promote osteoblastic differentiation and foster a specific inflammatory environment which favors bone formation. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
http://dx.doi.org/10.1016/j.spinee.2014.08.220 http://dx.doi.org/10.1016/j.spinee.2014.08.221 174. Osteoblasts Secrete Pro-Inflammatory Cytokines on PEEK but Anti-inflammatory Cytokines on Microstructured Titanium Barbara D. Boyan, PhD1, Rene Olivares-Navarrete, PhD2, Sharon L. Hyzy2, Paul J. Slosar, MD3, Peter F. Ullrich, Jr., MD4, Zvi Schwartz, PhD2; 1Virginia Commonwealth University School of Engineering, Richmond, VA, US; 2Georgia Institute of Technology, Atlanta, GA, US; 3 Spine Care Institute of San Francisco, San Francisco, CA, US; 4Neuro Spine Center of Wisconsin, SC, Appleton, WI, US BACKGROUND CONTEXT: Bone formation around an interbody fusion device is affected by the implant’s surface properties. Titianium alloy implants with a micro-rough surface texture promote differentiation of mesenchymal stem cells (MSCs) into osteoblasts in vitro. This is accompanied by production of factors that enhance bone formation and inhibit resorption. In animal studies comparing osteogenesis around smooth surfaced Ti alloy implants to Ti implants with micro-rough surfaces, peri-implant bone formation is greater around the rougher textured implants as is the force required to pull them out of bone. In contrast to their behavior on Ti alloy surfaces, MSCs cultured on PEEK exhibit only modest osteoblastic differentiation in vitro and a fibrous connective tissue interface is frequently observed in vivo. Production of osteogenic factors is also reduced, suggesting that the fibrous interface might result from local factors that promote inflammation. PURPOSE: The aim of the current study was to examine if the inflammatory microenvironment generated by cells on Ti alloy surfaces is affected by the surface microtexture and if it differs from that generated on PEEK. METHODS: Human MSCs were cultured on tissue culture plastic (TCPS), PEEK, smooth Ti-alloy (smooth Ti) or a micro-textured rough Ti-alloy (micro-tex Ti) disks for 7 days. Cell morphology and osteoblastic differentiation were as described previously (Gittens, Biomaterials, 2012): TCPS5PEEK ! smooth Ti-alloy ! rough Ti-alloy. mRNAs for proinflammatory cytokines were measured and fold changes compared with respect to TCPS. Data were analyzed by ANOVA followed by Bonferroni’s modification of Student’s t test. RESULTS: Cells grown on PEEK up-regulated mRNAs for chemokine ligand 2 (CCL2), interleukin 1b, IL6, IL8, and tumor necrosis factor alpha (TNF). These inflammatory cytokines favor formation of fibrous tissue. Cells grown on the micro-tex Ti surface had an 8-fold reduction in mRNAs for toll-like receptor 4 (TLR4). The reduction of these inflammatory cytokines fosters an osteogenic cellular environment MSCs on PEEK had reduced levels of the anti-inflammatory cytokine IL10 and increased levels of pro-inflammatory cytokines. Cells cultured on smooth Ti alloy had levels of these cytokines comparable to cells grown on TCPS. Cells grown on the micro-tex Ti surface had reduced levels of all three pro-inflammatory interleukins favoring osteogenesis versus fibrosis. mRNAs for proteins associated with cell death were also differentially expressed. Cells on PEEK had higher levels of factors strongly associated with cell death/ apoptosis. In contrast, cells cultured on the micro-tex Ti exhibited reduced cell-death cytokine factor levels. All results reached statistical significance (p!0.05). CONCLUSIONS: We previously showed that osteoblasts on micro-textured Ti produce pro-angiogenic factors whereas those on PEEK do not
175. A Comparison of Commercially Available Demineralized Bone Matrix with and without Human Mesenchymal Stem Cells in a Rodent Spinal Fusion Model Tetsuo Hayashi, MD1, Jeffrey C. Wang, MD2, Elizabeth L. Lord, MD1, Akinobu Suzuki, MD, PhD3, Shinji Takahashi, MD3, Trevor Scott, MD4, Haijun Tian, MD, PhD1, Kevin Phan, BS1, Michael D. Daubs, MD5; 1Los Angeles, CA, US; 2USC Spine Center, Los Angeles, CA, US; 3Osaka City University, Osaka, Japan; 4University of California Los Angeles Department of Orthopedic Surgery, Santa Monica, CA, US; 5Las Vegas, NV, US BACKGROUND CONTEXT: Several demineralized bone matrix (DBM) products are commercially available for use in spinal fusion surgery. Each product has different osteoinductive proteins due to different methods of preparation, storage and donor specifications. The efficacy of some DBM substances has been demonstrated in spinal fusion of rats. However, no previous study has reported the efficacy of DBM with human mesenchymal stem cells. There is added cost to the products with stem cells which should be justified via improved osteogenic potential. PURPOSE: The purpose of this study is to prospectively compare the fusion rate of three different commercially available DBM substances, both with and without human mesenchymal stem cells, an athymic rodent spinal fusion model. METHODS: A posterolateral fusion was performed in 32 mature athymic nude rats. Three groups of 8 rats were implanted with 1 of 3 DBMs (Trinity; DBM with stem cells, Grafton; DBM without stem cells, DBX; DBM without stem cells). A fourth group was used as a control group with sham surgery without implantation of any graft material. A dose of 0.3 cm3 per side (0.6 cm3 per animal) was used for each substance. Radiographs were performed at 2, 4, 8 weeks. The rats were sacrificed at 8 weeks. Overall fusion was determined by manual palpation testing and micro CT. RESULTS: Fusion rates at 8 weeks by radiographs for Trinity, Grafton and DBX were (8/8), (3/8) and (5/8), respectively. Significant difference was found between Trinity and Grafton (p50.01). The fusion rates by micro CT were similar to those by manual palpation testing. Overall fusion rates as determined by micro CT and manual palpation testing for Trinity, Grafton and DBX were (4/8), (3/8) and (3/8), respectively. The Trinity substance had the highest overall fusion rate, however, no significant difference was found among the groups. In terms of method of analysis, there is a significant difference between radiograph at 8 weeks (8/8) and micro CT (4/8) for Trinity, indicating that we overestimated the fusion by radiograph (p50.03). CONCLUSIONS: We demonstrated the efficacy of these DBM substances, however, the advantage in combination with stem cells, which was more expensive than the others, could not be found in terms of posterolateral fusion. When we evaluate the spinal fusion using DBM substance, CT analysis is necessary not to overestimate the fusion. FDA DEVICE/DRUG STATUS: Trinity (Approved for this indication), Graphton (Approved for this indication), DBX (Approved for this indication) http://dx.doi.org/10.1016/j.spinee.2014.08.222
Refer to onsite Annual Meeting presentations and postmeeting proceedings for possible referenced figures and tables. Authors are responsible for accurately reporting disclosures and FDA device/drug status at time of abstract submission.
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(Olivares-Navarrete et al., Spine J, 2012). Those findings, combined with the current results, suggest that fibrous tissue around the surface of PEEK implants is due to several factors: reduced osteoblastic differentiation of progenitor cells and production of an inhibitory inflammatory environment that favors cell death via apoptosis and necrosis. However, titanium alloy surfaces with complex micron scale and submicron scale roughness promote osteoblastic differentiation and foster a specific inflammatory environment which favors bone formation. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
http://dx.doi.org/10.1016/j.spinee.2014.08.220 http://dx.doi.org/10.1016/j.spinee.2014.08.221 174. Osteoblasts Secrete Pro-Inflammatory Cytokines on PEEK but Anti-inflammatory Cytokines on Microstructured Titanium Barbara D. Boyan, PhD1, Rene Olivares-Navarrete, PhD2, Sharon L. Hyzy2, Paul J. Slosar, MD3, Peter F. Ullrich, Jr., MD4, Zvi Schwartz, PhD2; 1Virginia Commonwealth University School of Engineering, Richmond, VA, US; 2Georgia Institute of Technology, Atlanta, GA, US; 3 Spine Care Institute of San Francisco, San Francisco, CA, US; 4Neuro Spine Center of Wisconsin, SC, Appleton, WI, US BACKGROUND CONTEXT: Bone formation around an interbody fusion device is affected by the implant’s surface properties. Titianium alloy implants with a micro-rough surface texture promote differentiation of mesenchymal stem cells (MSCs) into osteoblasts in vitro. This is accompanied by production of factors that enhance bone formation and inhibit resorption. In animal studies comparing osteogenesis around smooth surfaced Ti alloy implants to Ti implants with micro-rough surfaces, peri-implant bone formation is greater around the rougher textured implants as is the force required to pull them out of bone. In contrast to their behavior on Ti alloy surfaces, MSCs cultured on PEEK exhibit only modest osteoblastic differentiation in vitro and a fibrous connective tissue interface is frequently observed in vivo. Production of osteogenic factors is also reduced, suggesting that the fibrous interface might result from local factors that promote inflammation. PURPOSE: The aim of the current study was to examine if the inflammatory microenvironment generated by cells on Ti alloy surfaces is affected by the surface microtexture and if it differs from that generated on PEEK. METHODS: Human MSCs were cultured on tissue culture plastic (TCPS), PEEK, smooth Ti-alloy (smooth Ti) or a micro-textured rough Ti-alloy (micro-tex Ti) disks for 7 days. Cell morphology and osteoblastic differentiation were as described previously (Gittens, Biomaterials, 2012): TCPS5PEEK ! smooth Ti-alloy ! rough Ti-alloy. mRNAs for proinflammatory cytokines were measured and fold changes compared with respect to TCPS. Data were analyzed by ANOVA followed by Bonferroni’s modification of Student’s t test. RESULTS: Cells grown on PEEK up-regulated mRNAs for chemokine ligand 2 (CCL2), interleukin 1b, IL6, IL8, and tumor necrosis factor alpha (TNF). These inflammatory cytokines favor formation of fibrous tissue. Cells grown on the micro-tex Ti surface had an 8-fold reduction in mRNAs for toll-like receptor 4 (TLR4). The reduction of these inflammatory cytokines fosters an osteogenic cellular environment MSCs on PEEK had reduced levels of the anti-inflammatory cytokine IL10 and increased levels of pro-inflammatory cytokines. Cells cultured on smooth Ti alloy had levels of these cytokines comparable to cells grown on TCPS. Cells grown on the micro-tex Ti surface had reduced levels of all three pro-inflammatory interleukins favoring osteogenesis versus fibrosis. mRNAs for proteins associated with cell death were also differentially expressed. Cells on PEEK had higher levels of factors strongly associated with cell death/ apoptosis. In contrast, cells cultured on the micro-tex Ti exhibited reduced cell-death cytokine factor levels. All results reached statistical significance (p!0.05). CONCLUSIONS: We previously showed that osteoblasts on micro-textured Ti produce pro-angiogenic factors whereas those on PEEK do not
175. A Comparison of Commercially Available Demineralized Bone Matrix with and without Human Mesenchymal Stem Cells in a Rodent Spinal Fusion Model Tetsuo Hayashi, MD1, Jeffrey C. Wang, MD2, Elizabeth L. Lord, MD1, Akinobu Suzuki, MD, PhD3, Shinji Takahashi, MD3, Trevor Scott, MD4, Haijun Tian, MD, PhD1, Kevin Phan, BS1, Michael D. Daubs, MD5; 1Los Angeles, CA, US; 2USC Spine Center, Los Angeles, CA, US; 3Osaka City University, Osaka, Japan; 4University of California Los Angeles Department of Orthopedic Surgery, Santa Monica, CA, US; 5Las Vegas, NV, US BACKGROUND CONTEXT: Several demineralized bone matrix (DBM) products are commercially available for use in spinal fusion surgery. Each product has different osteoinductive proteins due to different methods of preparation, storage and donor specifications. The efficacy of some DBM substances has been demonstrated in spinal fusion of rats. However, no previous study has reported the efficacy of DBM with human mesenchymal stem cells. There is added cost to the products with stem cells which should be justified via improved osteogenic potential. PURPOSE: The purpose of this study is to prospectively compare the fusion rate of three different commercially available DBM substances, both with and without human mesenchymal stem cells, an athymic rodent spinal fusion model. METHODS: A posterolateral fusion was performed in 32 mature athymic nude rats. Three groups of 8 rats were implanted with 1 of 3 DBMs (Trinity; DBM with stem cells, Grafton; DBM without stem cells, DBX; DBM without stem cells). A fourth group was used as a control group with sham surgery without implantation of any graft material. A dose of 0.3 cm3 per side (0.6 cm3 per animal) was used for each substance. Radiographs were performed at 2, 4, 8 weeks. The rats were sacrificed at 8 weeks. Overall fusion was determined by manual palpation testing and micro CT. RESULTS: Fusion rates at 8 weeks by radiographs for Trinity, Grafton and DBX were (8/8), (3/8) and (5/8), respectively. Significant difference was found between Trinity and Grafton (p50.01). The fusion rates by micro CT were similar to those by manual palpation testing. Overall fusion rates as determined by micro CT and manual palpation testing for Trinity, Grafton and DBX were (4/8), (3/8) and (3/8), respectively. The Trinity substance had the highest overall fusion rate, however, no significant difference was found among the groups. In terms of method of analysis, there is a significant difference between radiograph at 8 weeks (8/8) and micro CT (4/8) for Trinity, indicating that we overestimated the fusion by radiograph (p50.03). CONCLUSIONS: We demonstrated the efficacy of these DBM substances, however, the advantage in combination with stem cells, which was more expensive than the others, could not be found in terms of posterolateral fusion. When we evaluate the spinal fusion using DBM substance, CT analysis is necessary not to overestimate the fusion. FDA DEVICE/DRUG STATUS: Trinity (Approved for this indication), Graphton (Approved for this indication), DBX (Approved for this indication) http://dx.doi.org/10.1016/j.spinee.2014.08.222
Refer to onsite Annual Meeting presentations and postmeeting proceedings for possible referenced figures and tables. Authors are responsible for accurately reporting disclosures and FDA device/drug status at time of abstract submission.