Demineralized Bone Grafts Research Articles

Tumor Treating Fields for Treatment of Spinal Metastasis

INTRODUCTION: Tumor treating fields(TTF) has never been described for treatment of spinal metastasis. We investigate the anti-mitotic effect of TTF to inhibit the growth of human cancer using cells in vitro and in vivo models of spinal metastasis. METHODS: In-vitro: human derived osteosarcoma (Krib-Luc-1) and lund adenocarcinoma (A549-Luc) cells were seeded in 5x5mm human demineralized bone grafts kept in culture while treated with 0 KHz (control) or 150 KHz of TTF for 14 days. Bioluminescence images (BLI) were obtained at baseline and 14 days. In-vivo: Krib-Luc-1 cells were surgically implanted via trasperitoneal approach to the L3 vertebra in nude mice. Animals were treated with 0 KHz or 150 KHz of TTF for 30 days or until paralysis. BLI were obtained at day 0 and every 7 days. MRI was obtained at day 22. Histological analysis was performed at the end of the experiment. Control and TTF treated groups were compared with two-tailed t-tests. RESULTS: In vitro: BLI of the control grafts demonstrated a median value of 1×10^10 photons/sec at 14 days, significantly higher than 1×10^8 photons/sec observed in the 150 KHz group (p < 0.0001). In Vivo: median time to paralysis in control animals was 25 days, all animals treated with TTF at 150 KHz reached the 30 day mark without deficits. BLI of the control group was 3.5×10^9 photons/sec significantly higher than 1×10^9 photons/sec in the 150 KHz TTF group (p = 0.0212). MRI and histological analysis confirmed significant smaller tumors in the treated group when compared to controls. CONCLUSIONS: Application of TTF 150 KHz reduced cellular proliferation in both in vitro and in vivo models of spinal metastasis. We believe TTF could become a groundbreaking treatment for spinal metastasis.

Tumor treating fields suppress tumor cell growth and neurologic decline in models of spinal metastases.

Spinal metastases can result in severe neurologic compromise and decreased overall survival. Despite treatment advances, local disease progression is frequent, highlighting the need for novel therapies. Tumor treating fields (TTFields) impair tumor cell replication and are influenced by properties of surrounding tissue. We hypothesized that bone's dielectric properties will enhance TTFields-mediated suppression of tumor growth in spinal metastasis models. Computational modeling of TTFields intensity was performed following surgical resection of a spinal metastasis and demonstrated enhanced TTFields intensity within the resected vertebral body. Additionally, luciferase-tagged human KRIB osteosarcoma and A549 lung adenocarcinoma cell lines were cultured in demineralized bone grafts and exposed to TTFields. Following TTFields exposure, the bioluminescence imaging (BLI) signal decreased to 10%-80% of baseline, while control cultures displayed a 4.48- to 9.36-fold increase in signal. Lastly, TTFields were applied in an orthotopic murine model of spinal metastasis. After 21 days of treatment, control mice demonstrated a 5-fold increase in BLI signal compared with TTFields-treated mice. TTFields similarly prevented tumor invasion into the spinal canal and development of neurologic symptoms. Our data suggest that TTFields can be leveraged as a local therapy within minimally conductive bone of spinal metastases. This provides the groundwork for future studies investigating TTFields for patients with treatment-refractory spinal metastases.

Experimental study of the use of oseto-cellular grafts in wrist arthrodesis

Introduction. Wrist arthrodesis is a surgery performed in advanced osteoarthritis of the wrist joint of various etiology, posttraumatic consequences or diseases of carpal bones. It is a rescue surgery and is performed with the cost of losing of range of movement, but remove the pain syndrome and increase the strength of the hand. Aim of study. Evaluation of osteo-cellular grafts (OCG) using in wrist arthrodesis in experimental study on laboratory animals. Material and Methods. The study was based on experimental research on 21 New Zealand rabbits, splited in 3 study groups. As methods of implementation of the study included: preparation of allogeneic demineralized bone grafts, bone marrow sampling and isolation of autologous stem cells, obtaining OCG, and performing 3 different techniques of wrist arthrodesis. Results. Imagistic results showed us, that the group were performed arthrodesis using combined graft with stem cells, the ankylosis were achieved faster. Histological examinations indicated more active involvement in the process of osteogenesis in the use of combined stem cell transplantation. Conclusion. Our study showed that compared to the control group, the arthrodesis of the wrist using the allograft have good impact in the process of osteogenesis, but the best results were performed by using allograft combined with stem cells.

Abstract 20: In vitro and in vivo investigation of tumor treating fields for treatment of spinal metastasis

Abstract Introduction: Tumor treating fields (TTF) are used for treatment of glioblastoma. Its utilization for spinal metastasis has never been described. We investigate the anti-mitotic effect of TTF to inhibit the growth of human cancer cells in vitro and in vivo models of spinal metastasis. Methods: In vitro: human derived osteosarcoma (Krib-luc-1) and lung adenocarcinoma (A549-luc) cells were seeded in 5 × 3mm human demineralized bone grafts kept in culture while treated with 0kHz (control) or 150kHZ of TTF for 14 days. Bioluminescence images (BLI) were obtained at baseline and 14 days. In vivo: Krib-Luc-1 cells were surgically implanted via transperitoneal approach to L3 vertebra in nude mice. Animals were treated with 0kHz or 150kHz for 30 days or until death. BLI were obtained at day 0 and every 7 days. MRI was obtained at day 22. Histological analysis was performed at the end of the experiment. Control and TTF-treated groups were compared with two-tailed t-tests. Results: In vitro: BLI of the control groups demonstrated 5-fold and 34-fold higher tumor signal (photons/sec) than corresponding 150 kHz TTF treatment groups at 14 days (A549 p=0.0289; KRIB p=0.00895). In vivo: All mice receiving 0 kHz treatment displayed hind limb paralysis by day 30, while mice treated with 150 kHz TTF displayed tail drop or no signs of paralysis. MRI and histology confirmed smaller tumors corroborating to BLI (3.67-fold change in photons/sec) (p=0.0212) when the 150 kHz TTF treatment group was compared to controls. Conclusions: Application of TTF at 150kHz reduced cellular proliferation in both in vitro and in vivo models of spinal metastasis. This is the first report of utilization of TTF for treatment of bony tumors and represents the first evidence that TTF could become a revolutionary therapy for spinal metastasis. Citation Format: Claudio Esteves Tatsui, Daniel Ledbetter, Christopher Alvarez-Breckenridge. In vitro and in vivo investigation of tumor treating fields for treatment of spinal metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 20.

Radiation sterilization of demineralized bone grafts in the light of hepatitis B and C infection prevention

Donor compact bone specimens infected by В, C hepatitis were exposed to the influence of fast electron flow in increasing doses (from 15 to 50 kGy) for the detection of minimum dose of radiation sterilization. The study of specimens on HBV and HCV markers showed that 50 and 36 kGy were close to minimum doses required for the inactivation of antigen structures of В, C hepatitis, respectively. The danger of virus hepatitis transmission by demineralized bone grafts is present if conventional normative doses of radiation sterilization (up to 35 kGy) are applied. Taking into account the side effect of radiation sterilization on the microstructure of bone grafts it is necessary to continue the search of methods for the preservation of plastic (conductive and inductive) bone properties during sterilization by fast electron flow in 50 kGy dose.

The effect of mesenchymal stem cells, demineralized bone graft and platelet-rich plasma on osteogenesis in rat tibia defects

Aim: Deformities of the jaw and face are often caused by infection, inflammation, and cystic and neoplastic pathological conditions. Defects with various aetiologies should be repaired promptly using the most appropriate approach to reconstruct the anatomical form. To treat defects, bone grafts with various combinations have been used. In particular, combinations including cellular products to enhance osteogenic properties have been implemented. In this study, we aimed to investigate the effects of different materials and cells on bone defects by using mesenchymal stem cells (MSCs), which are thought to have a positive effect on healing, demineralized bone graft (DMB) and platelet-rich plasma (PRP).
 Methodology: We used 55 female rats weighing between 200-250 g, four of which were used to obtain platelet-rich plasma. The remaining animals were divided into five groups. Group I (n = 6) was the operative control group, Group II (n = 24) was given DMB, Group III (n = 24) was given DMB+PRP, Group IV (n = 24) was given MSC+DBG and Group V (n = 24) was given DMB+PRP+MSC applied to rat tibial defects (10 mm x 3 mm x 2 mm).
 Results: Statistically significant differences were observed in bone osteoblastic activity in tibia defects among the groups (p<0.05).
 Conclusion: Bone regeneration was significantly improved in groups where MSCs were used in combination with DMB and PRP.
 
 How to cite this article: Erdoğmuş Z, Gülsün B. The effect of mesenchymal stem cells, demıneralızed bone graft and platelet-rıch plasma on osteogenesıs ın rat tıbıa defects. Int Dent Res 2021;11(Suppl.1):47-55. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.8
 
 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Osteoplastic material from demineralized of allocate in the treatment of primary and acute pulpitis in children

Relevance. Initial and acute forms of pulpitis are fairly common diseases and require urgent treatment. Existing methods of endodontic treatment do not have sufficient efficiency and the introduction of new methods and drugs is required to improve the effectiveness of the treatment.Purpose. Improving the effectiveness of treatment of initial and acute pulpitis of permanent teeth in children using allogeneic demineralized plastic material (CPM).Materials and methods. The surface structure of a demineralized bone graft (DCT) and an allogeneic composite plastic material (CPM) were studied by scanning electron microscopy (SEM Philips SEM 515) with an EDAX microanalysis prefix . In the clinic, CPM was used in 10 patients aged 9 to 15 years in the treatment of pulpitis of permanent teeth with unformed roots.Results. The morphological structure of alloplastic material is fine-pored , with pore sizes of 10-20 microns, uneven, with protrusions and depressions, sometimes with a pore size of up to 250 microns. Clinical laboratory and radiological methods of research in children in the long term up to 3 years have confirmed the effectiveness of CPM in the biological method of treatment of pulpitis in children. In 9 patients, a positive result was obtained with the preservation of pulp viability and the formation of dental roots.Conclusions. Allogeneic bone-plastic material, which has osteoplastic and antimicrobial properties in the treatment of pulpitis in children, allows to preserve the viability of the pulp and the possibility of full-fledged formation of tooth roots.

Histomorphometric Assessment of the Impact of Bovine Demineralized Bone Graft on Bone Healing Versus Autogenous, Allogeneic and Synthetic Grafts in Experimentally- Induced Critical Size Bone Defects in Rats

Aim: Bone tissue has the ability to heal itself (regeneration) and may restore its morphology and function when injured. However, healing may be limited in the case of large wounds. A “critical-size defect” is an intraosseous wound in a particular bone and species of animal that will not heal spontaneously morphologically and functionally during the lifetime of the animal. Autogenous bone grafts have been regarded as “gold standard” for treatment of critical-size bone defects. Known drawbacks of autogenous bone graft have led to research efforts focusing on different graft materials and resulted in several alternative substitutes including xenografts, allografts and synthetic graft materials. The aim of the present study was to perform a histomorphometric study to investigate the effect of bovine demineralized bone graft on bone healing in comparison to autogenous, allogeneic and synthetic graft materials when applied into critical size bone defects with a diameter of 5 mm. Materials and methods: Experimental animals were divided into 4 groups, each having 8 rats. In the control group, a mandibular defect was created and then filled with a bovine graft (Integros Bone Plus XS Adana/Turkey). In the experimental groups, autogenous bone was reinserted into the critical-size defect which was created using a trephine bur in Group I (autogenous group) and Group II received a human graft (Korea Bone Bank (KBB) Gasandong Keumcheongu Seoul/South Korea) to fill the critical-size defect. For Group III, a synthetic bone graft β-tricalcium phosphate (Cerasorb North Carolina/USA) was applied on the critical-size bone defect. Specimens were obtained for histomorphometric examination and rats were sacrificed on day 28. Results: Histomorphometric examination performed on day 28 to evaluate the relative effects of different graft materials on new bone formation showed no significant difference in the volume of newly formed bone between groups receiving autogenous bone graft, allograft and bovine xenograft but a significant difference was observed versus synthetic bone graft group. Conclusion: While autogenous bone graft is currently regarded as the gold standard for bone regeneration, the difficulties in harvesting and application of autografts limit their use. Our results demonstrate that bovine bone graft may be used as a safe and effective alternative to autogenous bone graft.

The local cytokine and growth factor response to recombinant human bone morphogenetic protein-2 (rhBMP-2) after spinal fusion

Background ContextThe systemic response regarding cytokine expression after the application of recombinant human bone morphogenetic protein-2 (rhBMP-2) in a rat spinal fusion model has recently been defined, but the local response has not been defined. Defining the local cytokine and growth factor response at the fusion site will help explain the roles of these molecules in the fusion process, as well as that of rhBMP-2. Our hypothesis is that the application of rhBMP-2 to the fusion site will alter the local levels of cytokines and growth factors throughout the fusion process, in a manner that is different from the systemic response, given the tissue-specific effects of rhBMP-2. PurposeThe purpose of this study was to evaluate the local cytokine and growth factor response after the application of rhBMP-2 in a rat spinal fusion model. Study Design/SettingThis was a basic science animal model study. MethodsThis study was partially funded by a physician-sponsored grant from Medtronic. A total of 135 Wistar rats (age 8 weeks, weighing approximately 300–400 g) underwent L4–L5 posterolateral intertransverse fusion with demineralized bone graft (approximately 0.4-cm3 rat demineralized bone matrix [DBM] per side). In the first group, 10 µg of rhBMP-2 on an allograft collagen sponge (ACS) was added to the fusion site with approximately 0.4-cm3 rat DBM per side. In the second group, 100 µg of rhBMP-2 on an ACS was added to the fusion site with approximately 0.4-cm3 rat DBM per side, and the third experiment was the control group, which consisted of only an ACS plus 0.4-cm3 DBM per side. There were nine groups of five animals each per experiment. Each group was sacrificed at time points up to 4 weeks (1, 6, 24, and 48 hours, and 4, 7, 14, 21, and 28 days after surgery). At sacrifice, the DBM, transverse processes, and any new bone formed were harvested, immediately frozen in liquid nitrogen, and prepared for protein extraction. ELISA was performed to compare the levels of various cytokines (interleukin [IL]-1β, tumor necrosis factor alpha, IL-6, IL-1RA [IL-1 receptor antagonist], IL-4, and IL-10) and growth factors (vascular endothelial growth factor [VEGF], endothelia growth factor [EGF], insulin-like growth factor-1 [IGF-1], platelet derived growth factor [PDGF], transforming growth factor beta [TGF-β]) that are known to be involved in the fusion-fracture healing process. Fusion was evaluated on the rats sacrificed at 28 days by manual palpation and microcomputed tomography (microCT) by two independent observers. ResultsThe expression of cytokines and growth factors varied throughout the fusion process at each time point. In the groups treated with rh-BMP-2, IL-6 and IL-1RA had higher expression in the early time points (1 and 6 hours). Tumor necrosis factor alpha demonstrated significantly lower expression in the groups treated with rhBMP-2 at Days 1, 2, and 4. At the early time points (1 and 6 hours), in the groups treated with rhBMP-2, all of the growth factors IGF-1, VEGF, platelet derived growth factor AB (PDGF-AB), TGF-β had equal or lower expression compared with controls. At 24 hours, there was a peak in IGF-1, VEGF, and PDGF-AB. These growth factors then declined, with IGF-1 and PDGF-AB having a second peak at Day 7. At 4 weeks, all of the rhBMP-2-treated animals fused based on manual palpation and microCT. The control group had four of five rats fused based on manual palpation and two of five rats based on microCT. ConclusionsThere is significant variability in the expression of cytokines throughout the fusion process after treatment with rhBMP-2. The inflammatory response appears to peak early (1 and 6 hours), followed by a significant decrease with rhBMP-2 treatment. However, the growth factor expression appears to be suppressed early (1 and 6 hours), followed by a peak at 24 hours, and a second peak at Day 7.

Re-operations in relapsing frontitis after Belogolovov frontal sinus opening

The authors studied the causes of development of recurrent chronic purulent frontal sinusitis after Belogolovov frontal sinus opening in 26 patients at the period of 2010–2016. The article discusses the specific features of formation of frontal ostium using demineralized bone grafts and polytetrafluoroethylene, describing the disadvantages of each of the materials. It was decided to return to the previously suggested original method of formation of frontal ostium using a combined drain tube consisting of a rigid tubular fragment and a homotissue component (femoral artery), which is the natural fluid conductor in the human body.

Augmentation of bone healing in delayed and atrophic nonunion of fractures of long bones by partially decalcified bone allograft (decal bone).

Background:Autograft from iliac crest is considered as gold standard for augmentation of bone healing in delayed and nonunion of fractures. Bone demineralized with 0.6N hydrochloric acid has shown to retain its osteoinductive capacity. We report the outcome of partially decalcified bone allograft (decal bone) in the treatment of delayed union and atrophic nonunions of bones.Materials and Methods:Twenty patients with clinicoradiological diagnosis of delayed union or atrophic nonunion of long bone fractures were included in this retrospective study. Patients at extreme of ages (<18 years and >60 years), pathological fractures, metabolic bone diseases, infected nonunion, hypertrophic nonunion and those having systemic illness like diabetes mellitus and on drugs that impair fracture healing were excluded from the study. Decal bone was prepared in the bone bank and maintained in department of orthopedics. Allografting was done in 20 patients of delayed union (9/20) and atrophic nonunion (11/20) of long bone fractures with mean age of 34 years (range 18–55 years). The bones involved were humerus (8/20), tibia (7/20) and femur (5/20). Fourteen patients underwent treatment in the form of internal fixation and allografting and six patients were operated with osteoperiosteal allografting.Results:Nineteen patients achieved union in mean time of 14.9 weeks range (range 8–20 weeks). Eight patients had serous discharge from the operative site that subsided in 11 days (range 4–21 days). One patient had pus discharge that required repeat debridement and antibiotics for 6 weeks. The fracture healed in 16 weeks.Conclusion:The partially decalcified bone allograft is an effective modality for augmentation of bone healing without complication associated with autograft like donor site morbidity, increased blood loss and increase in the surgical time.

NELL-1 based demineralized bone graft promotes rat spine fusion as compared to commercially available BMP-2 product

BackgroundSpinal fusion is among the most commonly performed orthopaedic procedures. Unfortunately, current treatments such as autologous bone grafting or recombinant proteins (BMP-2) have numerous clinical shortcomings. Here, we directly compare the efficacy of NELL-1, a novel osteoinductive growth factor, to two currently available treatments, (1) recombinant BMP-2 and (2) iliac crest bone grafting, in a spinal fusion model. MethodsTwenty-six skeletally mature athymic rats underwent posterolateral spine fusion of L4/L5 vertebrae. Treatment groups included NELL-1 (10 and 50μg) in a demineralized bone matrix (DBX), as compared to BMP-2 (90μg) in an absorbable collagen sponge (ACS) or morselized iliac crest bone. Scaffolds without recombinant protein were used as controls. Animals were sacrificed at 4weeks post-operative and fusion was assessed by manual palpation, radiography [high-resolution X-ray, micro-computed tomography (microCT)], histology (hematoxylin and eosin, Masson’s trichrome) and immunohistochemistry (osteocalcin). ResultsResults showed 100% fusion in all NELL-1- and BMP-2-treated samples. In contrast, lower rates of fusion were observed in scaffold-only and bone graft treatment groups. MicroCT scans revealed radiographic evidence of fusion among spines treated with NELL-1. Bone bridging was also observed with BMP-2 treatment, but was accompanied by inner radiolucency, suggesting cyst-like bone formation. Histologically, NELL-1-treated grafts showed increased bone formation, endochondral ossification and vascularization. Although BMP-2 treated grafts exhibited increased bone formation and angiogenesis, numerous adipocytes were also observed. ConclusionNELL-1-based bone grafts are comparable to BMP-2+ACS in spinal fusion efficacy. Histological differences were observed however, including robust endochondral ossification with NELL-1 treatment as compared to lipid-filled bone with BMP-2 treatment. These findings suggest NELL-1 based bone grafts show promise for future efforts in skeletal tissue engineering.

Placement of endosseous implant in infected alveolar socket with large fenestration defect: A comparative case report

Placement of endosseous implants into infected bone is often deferred or avoided due to fear of failure. However, with the development of guided bone regeneration [GBR], some implantologists have reported successful implant placement in infected sockets, even those with fenestration defects. We had the opportunity to compare the osseointegration of an immediate implant placed in an infected site associated with a large buccal fenestration created by the removal of a root stump with that of a delayed implant placed 5 years after extraction. Both implants were placed in the same patient, in the same dental quadrant by the same implantologist. GBR was used with the fenestration defect being filled with demineralized bone graft* and covered with collagen membrane**. Both implants were osseointegrated and functional when followed up after 12 months.

Experiences using IAEA Code of practice for radiation sterilization of tissue allografts: Validation and routine control

Problems of tissue allografts in using International Standard (ISO) 11137 for validation of radiation sterilization dose (RSD) are limited and low numbers of uniform samples per production batch, those are products obtained from one donor. Allograft is a graft transplanted between two different individuals of the same species. The minimum number of uniform samples needed for verification dose (VD) experiment at the selected sterility assurance level (SAL) per production batch according to the IAEA Code is 20, i.e., 10 for bio-burden determination and the remaining 10 for sterilization test. Three methods of the IAEA Code have been used for validation of RSD, i.e., method A1 that is a modification of method 1 of ISO 11137:1995, method B (ISO 13409:1996), and method C (AAMI TIR 27:2001). This paper describes VD experiments using uniform products obtained from one cadaver donor, i.e., cancellous bones, demineralized bone powders and amnion grafts from one life donor. Results of the verification dose experiments show that RSD is 15.4 kGy for cancellous and demineralized bone grafts and 19.2 kGy for amnion grafts according to method A1 and 25 kGy according to methods B and C.

Bone-Demineralized bone-Bone Grafts for Ligament Reconstruction

Ligament reconstruction with the use of novel demineralized bone grafts was investigated in a rabbit model. By demineralizing only the central portions of the long bone samples, the grafts had a configuration of the bone-tendon-bone graft and were flexible in bending. Strip type grafts made from femur, stick type grafts from tibia, and tube type grafts from metacarpal bones were prepared and their performances were evaluated by tensile testing and animal experiments for medial collateral ligament (MCL) and anterior cruciate ligament (ACL) reconstruction. The maximum strength of the strip and stick type grafts were about half of that of MCL, and that of tube type grafts was also about half of that of ACL. The survival rate of strip type grafts in MCL reconstruction was about 50%, and that of stick type was about 60%. In ACL reconstruction, the survival rate of strip type grafts was 0%, that of stick type was 10%, whereas that of tube type grafts was 50%, and that of tube type grafts reinforced with suture was 60%. The strip and stick type grafts might be useful for MCL reconstruction and the tube type grafts might be available for ACL reconstruction with suitable reinforcements.

Lumbar Posterolateral Fusion Using Demineralized Bone Matrix

Study Design: A retrospective study. Objectives: To compare the efficacy of demineralized bone matrix as a bone graft extender in lumbar posterolateral fusion with cases using an autogenous iliac bone graft. Summary of Literature Review: Since demineralized bone grafts were introduced for bone graft extension in 1995, many types of demineralized bone matrices have been used with improved fusion rates. Materials and Methods: From October 2004 to December 2005, demineralized bone matrices were used as iliac bone graft extenders in 49 cases (Group I) of lumbar posterolateral fusion, compared with 50 cases receiving autogenous grafts (Group II) similar in age, bone marrow density, and number of fusion levels. Fusion status was graded by the Lenke classification and data was analyzed using a chi-square test through SPSS v.10.0. Results: Group I had Lenke A in 7 cases (14.3%), B in 21 cases (42.9%), C in 15 cases (30.6%), and D in 6 cases (12.2%). Group II had Lenke A in 9 cases (18.0%), B in 26 cases (52.0%), C in 12 cases (24.0%), and D in 3 cases (6.0%). There was no statistical difference in fusion rate. Conclusion: Demineralized bone matrix could be used as a bone graft extender in lumbar posterolateral fusion.

Mesenchymal Stem Cell Sheets Revitalize Nonviable Dense Grafts: Implications for Repair of Large-Bone and Tendon Defects

Large musculoskeletal defects are commonly reconstructed with allogeneic grafts. As cryopreserved allogeneic grafts lack viable cells, this often results in poorer clinical outcome. Current technology can not incorporate large number of cells to the dense grafts. This study aimed to investigate the feasibility of fabricating sheets of mesenchymal stem cells (MSCs) to revitalize cryopreserved grafts. Human MSCs were isolated, characterized, and cultured to form a cell sheet in the presence of ascorbic acid. Once a sheet of MSCs was obtained, it was assembled onto the demineralized bone grafts or frozen tendon grafts by a wrapping technique. Then the assembled structure was cultured for 3 weeks. The macro morphology, histology, and immunohistochemistry of the grafts were evaluated. It was found that MSCs were able to form coherent cellular sheets within 3 weeks. When assembled with demineralized bone matrix, MSC sheets were similar to in situ periosteum and were able to differentiate into the osteochondral lineage. When assembled with frozen tendon graft, MSCs sheets were well-incorporated within the tissue sheath (peritenon) around the tendon, and adopted the characteristic spindle-shaped morphology of tenocyte-like cells. The results therefore demonstrated that MSCs sheets are easily fabricated and can maintain their differentiation potential within particular scaffolds, which would suggest a novel and convenient strategy for revitalizing large tissue grafts to improve clinical outcome.

221 脱灰骨グラフトによる家兎膝前十字靭帯の再建(OS1-07 : ティッシュ・エンジニアリング,マイクロ・ナノバイオメカニクス)

221 脱灰骨グラフトによる家兎膝前十字靭帯の再建(OS1-07 : ティッシュ・エンジニアリング,マイクロ・ナノバイオメカニクス)

Extensive Neglected Psammomatoid Ossifying Fibroma With Craniofacial Deformity

The psammomatoid ossifying fibroma is a rare and aggressive lesion that usually arises from the sinonasal region. The lesion is well circumscribed with the pathognomonic feature of concentric or laminated spherical ossicles that appear similar to psammoma bodies. The authors report a case of an extensive and neglected psammomatoid ossifying fibroma in a 10-year-old West African girl. She had a 5-year history of a slowly growing tumor, which at presentation was 15 cm in diameter and had resulted in left craniofacial deformity as well as left visual impairment. Due to the large tumor, the surgical resection plan necessitated a cranio-facial neurosurgical approach in combination with autogenous bone grafts for cranofacial reconstruction, and allogenous demineralized bone grafts for donor site coverage. In addition, preoperative embolization was utilized to reduce tumor vascularity. However, this embolization resulted in reduction of pericranial flap vascularity, leading to flap ischemia, infection and subsequent removal of necrotic autogenous bone graft. Ultimately, the objectives of large tumor resection and acceptable aesthetic outcome were met after controlling an episode of postoperative infection.

Effects of low-dose cyclosporin on osteogenesis of human demineralized bone grafts in a surgically created mandibular defect in rats.

Demineralized freeze-dried bone matrix (DFDBM) stimulates new bone formation; however, immune reactions from the residual antigens of prepared grafts might play a role in inducing osteogenesis. This study examined whether cyclosporine-A (CsA), an immunosuppressant, enhanced the DFDBM-induced new bone formation. After creating a bony defect in the posterior mandible, 40 male Sprague-Dawley rats were divided into four groups of 10 each: no graft with mineral oil (control); no graft with CsA in mineral oil; DFDBM with mineral oil; and DFDBM with CsA in mineral oil (combined therapy). CsA was administered at 2 mg/kg body weight. Five rats in each group were sacrificed at days 10 and 28 and tissue samples were taken for histological examination. Soft tissue was observed in the defects of all animals without grafts, whereas the repaired hard tissue formed in the defects of animals with grafts. Histometery, which was performed only at day 10, revealed both DFDBM and CsA therapies produced a significant increase in the total area of repaired hard tissue. Only CsA therapy significantly increased the new bone area. Compared with the DFDBM group, the composition of the repaired hard tissue in the combined therapy group shifted; i.e., the new bone area increased but the residual particle area decreased. The cartilage formation was greater in the combined therapy group than the DFDBM group. Within the limitations of this study, we suggest that the DFDBM grafts play a major role, which could be enhanced by CsA, in the induction of new bone formation, especially at an early phase.