Reconstruction Of Calvarial Defects Research Articles

MiR-26b-5p/TET3 regulates the osteogenic differentiation of human bone mesenchymal stem cells and bone reconstruction in female rats with calvarial defects.

MicroRNAs (miRNAs) play critical roles in the osteogenic differentiation of human bone mesenchymal stem cells (hBMSCs), but the mechanism by which miRNAs indirectly modulate osteogenesis remains unclear. Here, we explored the mechanism by which miRNAs indirectly modulate gene expression through histone demethylases to promote bone regeneration. Bioinformatics analysis was performed on hBMSCs after 7 days of osteogenic induction. The differentially expressed miRNAs were screened, and potential target mRNAs were identified. To determine the bioactivity and stemness of hBMSCs and their potential for bone repair, we performed wound healing, Cell Counting Kit-8 (CCK-8), real-time reverse transcription quantitative polymerase chain reaction (RT‒qPCR), alkaline phosphatase activity, alizarin red S (ARS) staining and radiological and histological analyses on SD rats with calvarial bone defects. Additionally, a dual-luciferase reporter assay was utilized to investigate the interaction between miR-26b-5p and ten-eleven translocation3 (TET3) in human embryonic kidney 293T cells. The in vitro and in vivo results suggested that miR-26b-5p effectively promoted the migration, proliferation and osteogenic differentiation of hBMSCs, as well as the bone reconstruction of calvarial defects in SD rats. Mechanistically, miR-26b-5p bound to the 3' untranslated region of TET3 mRNA to mediate gene silencing. MiR-26b-5p downregulated the expression of TET3 to increase the osteogenic differentiation of hBMSCs and bone repair in rat calvarial defects. MiR-26b-5p/TET3 crosstalk might be useful in large-scale critical bone defects.

The U-Turn Tournedos (UTT) Flap: A Technical Surgical Evolution for Deep Complex Calvarial Defects.

Patients treated for complex oncological calvarial defects are at a higher risk of severe complications (38%): infection, meningitis, dehiscence, and hardware/brain exposure. The patient cohorts at our center have led to the development of the "U-Turn" technical (UTT) addition of our previously reported turnover "tournedos" myocutaneous latissimus dorsi free flap. This allows for an improved ability to fill these large, round, complex defects, maintaining the safety of our original surgical technique, while improving aesthetic outcomes.A single-institution case series of complex microsurgical reconstructions for full-thickness oncologic calvarial defects using the UTT addition was reviewed. A free 30 cm latissimus dorsi myocutaneous flap was harvested, deepithelialized in-situ, and turned over with the dermal component laying on the avascular reconstructed dura. Both ends were positioned next to each other into a U shape and sutured together, creating a 15 cm round paddle.Fifty two complex microsurgical procedures for oncological calvarial defect reconstruction were performed. The 7 most recent were ideal for the UTT addition. There were no instances of microvascular thrombosis, infection, cerebral spinal fluid leak, or major wound healing problems. All procedures provided stable volume and full coverage, with all patients requiring debulking and contouring to achieve optimal aesthetic results. All flaps remained stable after debulking.The UTT addition takes the previously established "tournedos" latissimus dorsi free flap to another level of reconstruction, providing a larger volumetric filler, round shape, better defect filling, better durability, and better aesthetics, even in irradiated and/or infected calvarial chronic wound bed.

Cathelicidin LL37 Promotes Osteogenic Differentiation in vitro and Bone Regeneration in vivo.

Different types of biomaterials have been used to repair the defect of bony orbit. However, exposure and infections are still critical risks in clinical application. Biomaterials with characteristics of osteogenesis and antibiosis are needed for bone regeneration. In this study, we aimed to characterize the antimicrobial effects of cathelicidin-LL37 and to assess any impacts on osteogenic activity. Furthermore, we attempted to demonstrate the feasibility of LL37 as a potential strategy in the reconstruction of clinical bone defects. Human adipose-derived mesenchyme stem cells (hADSCs) were cultured with different concentrations of LL37 and the optimum concentration for osteogenesis was selected for further in vitro studies. We then evaluated the antibiotic properties of LL37 at the optimum osteogenic concentration. Finally, we estimated the efficiency of a PSeD/hADSCs/LL37 combined scaffold on reconstructing bone defects in the rat calvarial defect model. The osteogenic ability on hADSCs in vitro was shown to be dependent on the concentration of LL37 and reached a peak at 4 μg/ml. The optimum concentration of LL37 showed good antimicrobial properties against Escherichia coli and Staphylococcus anurans. The combination scaffold of PSeD/hADSCs/LL37 showed superior osteogenic properties compared to the PSeD/hADSCs, PSeD, and control groups scaffolds, indicating a strong bone reconstruction effect in the rat calvarial bone defect model. In Conclusion, LL37 was shown to promote osteogenic differentiation in vitro as well as antibacterial properties. The combination of PSeD/hADSCs/LL37 was advantageous in the rat calvarial defect reconstruction model, showing high potential in clinical bone regeneration.

Osteogenic and angiogenic lineage differentiated adipose-derived stem cells for bone regeneration of calvarial defects in rabbits.

Cell sheet techniques are widely used in bone engineering. However, vascularization remains a challenge in fabricating vascularized engineered bone. The goal of this study was to induce adipose-derived stem cell (ADSC) osteogenic and angiogenic lineage differentiation and investigate the use of bidiretionally differentiated ADSCs for bone regeneration. ADSCs were cultured to form an osteogenic cell sheet. Other ADSCs were induced to differentiate into endothelial progenitor cells (EPCs), which were identified and characterized by morphological observation and CD31 immunofluorescent staining. Then, the ADSC sheet-EPC complexes were implanted subcutaneously into nude mice, while ADSC sheets alone were implanted as a control. After 8 weeks of transplantation, microcomputed tomography (micro-CT) and histological observation were used to assess bone formation. We then implanted the complexes in calvarial defects in rabbits and assessed bone repair by micro-CT and histological analysis. The ADSC sheets consisted of multiple layers of cells and extracellular matrix. The obtained EPCs formed capillary-like structures and expressed the specific antigen marker CD31. The osteogenic ADSC sheet-EPC complexes formed dense and well-vascularized new bone tissue at 8 weeks after implantation. Bone density was significantly lower in the control group than in the complex group (p < .05). In addition, the reconstruction of calvarial defects in rabbits in complex group was obviously greater than that in the control group (p < .05). These results suggested that the approach of engineering bone tissue with bidiretionally differentiated ADSCs enabled bone regeneration, thus offering a promising strategy for repairing bone defects.

Management of Skull Fractures and Calvarial Defects.

Scalp and calvarial defects can result from a myriad of causes including but not limited to trauma, infection, congenital malformations, neoplasm, and surgical management of tumors or other pathologies. While some small, nondisplaced fractures with minimal overlying skin injury can be managed conservatively, more extensive wounds will need surgical repair and closure. There are many autologous and alloplastic materials to aid in dural and calvarial reconstruction, but no ideal reconstructive method has yet emerged. Different reconstructive materials and methods are associated with different advantages, disadvantages, and complications that reconstructive surgeons should be aware of. Herein, we discuss different methods and materials for the surgical reconstruction of calvarial defects.

Split-rib graft cranioplasty: Our experience and tips to achieve optimum results

Background: Calvarial defect reconstruction can be performed using a wide range of materials which can be divided into autologous and alloplastic options each with their own advantages and disadvantages. Limiting factors of available options include the risk of infection, absorption, cost, and damage to adjacent tissue. Here, we present our experience of calvarial reconstruction using autologous split-rib graft along with technical details of the surgical procedure. Materials and Methods: Our retrospective study included 22 patients over 6 years. All the patients were operated by the same team, and records were maintained. Patients were followed up for at least 2 years. Results: Results achieved were found to be excellent with no major postoperative complications. Patient satisfaction was motivating, and contour of the cranium was acceptable. There was negligible residual or recurrent deformity in our 2-year follow-up. Conclusions: Calvarial reconstruction with autologous bone graft is superior compared to alloplastic materials. Reconstruction with the rib graft gives optimum results which can be used in most clinical scenarios, including pediatric patients.

Hybrid scaffolds of Mg alloy mesh reinforced polymer/extracellular matrix composite for critical-sized calvarial defect reconstruction.

The challenge of developing scaffolds to reconstruct critical-sized calvarial defects without the addition of high levels of exogenous growth factor remains relevant. Both osteogenic regenerative efficacy and suitable mechanical properties for the temporary scaffold system are of importance. In this study, a Mg alloy mesh reinforced polymer/demineralized bone matrix (DBM) hybrid scaffold was designed where the hybrid scaffold was fabricated by a concurrent electrospinning/electrospraying of poly(lactic-co-glycolic acid) (PLGA) polymer and DBM suspended in hyaluronic acid (HA). The Mg alloy mesh significantly increased the flexural strength and modulus of PLGA/DBM hybrid scaffold. In vitro results demonstrated that the Mg alloy mesh reinforced PLGA/DBM hybrid scaffold (Mg-PLGA@HA&DBM) exhibited a stronger ability to promote the proliferation of bone marrow stem cells (BMSCs) and induce BMSC osteogenic differentiation compared with control scaffolding materials lacking critical components. In vivo osteogenesis studies were performed in a rat critical-sized calvarial defect model and incorporated a variety of histological stains and immunohistochemical staining of osteocalcin. At 12weeks, the rat model data showed that the degree of bone repair for the Mg-PLGA@HA&DBM scaffold was significantly greater than for those scaffolds lacking one or more of the principal components. Although complete defect filling was not achieved, the improved mechanical properties, promotion of BMSC proliferation and induction of BMSC osteogenic differentiation, and improved promotion of bone repair in the rat critical-sized calvarial defect model make Mg alloy mesh reinforced PLGA/DBM hybrid scaffold an attractive option for the repair of critical-sized bone defects where the addition of exogenous isolated growth factors is not employed.

Clinical Outcomes of Digital Three-Dimensional Hydroxyapatite in Repairing Calvarial Defects.

The objective of this article is to present the long-term outcomes of digital three-dimensional (3D) hydroxyapatite (HA) implants used for calvarial defects. Porous HA provide good results and have many characteristics, making it suitable for calvarial defect reconstruction. However, using HA may be associated with potentially serious complications, including infection and exposure. The authors used digital 3D HA for cranioplasty for many years and accumulated considerable experience from using it. The authors found that digital 3D HA is an effective method for cranioplasty, showing low complication rate. A total of 57 patients underwent calvarial defect reconstruction with 3D HA from June 2009 to August 2016. The follow-up period was 1 to 5 years. Most patients (91.2%) were greatly satisfied with the esthetic outcomes of the surgery. The highest rate of complication was seroma (8.8%). Two patients developed postoperative infections (3.5%). One patient with infections was successfully treated with antibiotic therapy. Another patient was required to undergo an extensive surgical debridement followed by delayed autogenous bone reconstruction. One patient suffered from implant exposure. No hematoma, unexpected fractures, asymmetry, and contour or implant abnormalities occurred. The digital 3D HA implant was highly biocompatible and durable for the reconstruction of calvarial defects. With appropriate treatment, the proposed method was able to achieve a functional and cosmetic reconstruction with lesser complications.

Outcomes of Titanium Mesh Cranioplasty in Pediatric Patients.

Cranial defects in children have been repaired with various materials ranging from autologous bone to synthetic materials. There is little published literature on the outcomes of titanium mesh cranioplasty (TMC) in calvarial reconstruction in the pediatric population. This study evaluates a pediatric cohort who underwent calvarial defect reconstruction with titanium mesh and assesses the efficacy and outcomes of TMC. An Institutional Review Board approved retrospective review of patients ≤18 years of age who underwent cranioplasty from 1999 to 2014 at 2 centers was performed. The cohort undergoing TMC was studied. A total of 159 cranioplasties were performed. Autologous reconstruction included 84 bone flap replacements and 36 split calvarial bone graft reconstructions. Six patients underwent PEEK implant reconstruction. Titanium mesh cranioplasty was performed on 33 patients. Two patients underwent 2 separate cranioplasties. The median age of patients was 6 years (19 months to 18 years). The most common underlying etiologies were congenital syndromes/craniosynostosis (13 patients), and trauma (11). The majority of patients had prior cranial surgeries (85%). Various types of titanium mesh were used with sizes ranging from 2×3 cm to 19×20 cm, with some patients requiring distinct areas of defect reconstruction. Perioperative complications were noted in 2 patients that subsequently improved. Two patients had late soft tissue problems with complications of wound infections requiring resection of a portion of the mesh. Patients were followed an average of 4 years (range 13 days to 6.8 years), with 2 patients lost to follow-up. Overall, all patients with follow-up achieved a cranial contour with good symmetry to the unaffected side, as well as effective protection to the brain. Titanium mesh cranioplasty is an effective option for correcting pediatric cranial defects when autologous bone availability is limited and soft tissue coverage allows placement of an implant. The interim outcome for these patients is favorable with few complications and no evidence of growth restriction in the authors' series. Follow-up will be ongoing for these patients.

A Study of Reconstruction of Calvarial Defect in Varied Etiology and Its Surgical Outcome

A Study of Reconstruction of Calvarial Defect in Varied Etiology and Its Surgical Outcome

Evaluation of Crystallized Biosilicate in the Reconstruction of Calvarial Defects.

The objective of this study was to assess the bone repair process of crystallized Biosilicate in surgically created defects on rats' calvaria. This biomaterial was recently developed for odontological use. We used fifteen rats (rattus norvegicus albinus, Wistar), and two 5 mm surgical defects were performed on each of them; the defects were made with trephine drill on the calvarium region prior to the biomaterial placement. Groups were divided as follows: Group 1-defect filled with clot; Group 2-defect filled with crystallized Biosilicate. After 7, 14 and 28 days the animals were killed, the parts were retrieved and slides were prepared for histological studies. Bone formation was satisfactory in all groups, with direct contact between biomaterial surface and bone and absence of infection signs. The 28 days periods showed better results, and statistically significant difference between Clot Group (90.2 %) and Biosilicate (58 %; p = 0.002) was seen, regarding presence of bone tissue on the surgical defects. Our study revealed that defects filled with clot present better results on bone formation compared to crystallized Biosilicate, which is considered a biocompatible material with favorable osteoconductive properties.

Calvarial Reconstruction with BMP-2

INTRODUCTION: While bone morphogenetic protein-2 (BMP-2) demonstrates promise as a therapy for calvarial bone regeneration, its application remains controversial due to concern for side effects such as heterotopic ossification or malignant transformation. Meanwhile, bone marrow cells (BMCs) have demonstrated therapeutic promise, but therapies remain to be optimized. The aim of this study was to augment the efficacy of bone marrow cell mediated bone regeneration through application of a low dose of rhBMP-2. METHODS: Subtotal calvariectomy defects measuring 7.5 x 7.5 mm2 were created in 12-week old New Zealand White rabbits. Defects were reconstructed in one of three groups: Group 1, acellular dermal matrix (ADM) soaked in PBS overnight [ADM/PBS, n=3]; Group 2, ADM soaked overnight in DMEM with 150,000 bone marrow cells from the femur of a New Zealand White rabbit [ADM/BMCs, n=3]; and Group 3, ADM and BMCs with 1.78 μg of BMP-2 applied by ink-jet based biopatterning [ADM/BMCs/BMP-2 n=3]. Animals underwent serial CT imaging at 0, 2, 4 and 6 weeks postoperatively, followed by euthanization and histological analysis. CTs were reconstructed utilizing Amira software (Visage Imaging, San Francisco, CA, USA), and areas of translucency were calculated using ImageJ (NIH) to determine change in defect area relative to time zero (baseline value). RESULTS: At 6 weeks compared to time zero, ADM/PBS resulted in 45.2% healing (standard deviation 30.1%), and ADM/BMCs resulted in 54.1% healing (standard deviation 12.7%). Treatment with ADM/BMCs/BMP-2 resulted in 78.6% healing (standard deviation 11.6%); there was no significant difference between groups (Figure 1). Histologically, bone in each group was similar, consisting of islands of compact, cellular bone.Figure 1: Percent Defect Healing.CONCLUSION: Compared to treatment with ADM/PBS only, addition of BMCs for reconstruction of an acute calvarial defect trended toward better results, and addition of BMP-2 to this regimen further optimized outcomes. Combination cell/growth factor therapy may enable successful reconstruction of calvarial defects without side effects related to higher dose.

Complex Scalp, Skull, and Dural Defect Reconstruction Using a Turnover “Tournedos” Myocutaneous Free Flap

The latissimus dorsi flap is one of the most commonly used flaps for calvarial defect reconstruction. In the setting of radiation and/or chronic infection and when skeletal reconstruction of the cranium is not recommended, standard calvarial reconstruction needs to be refined. The standard use of the latissimus dorsi only was associated with potential dead space over the dura, limited skin paddle size, and potential external contour irregularities. In this study, we present our approach to complex calvarial reconstruction with free tissue transfer without bone grafting while avoiding contour deformities in 1 efficient surgical procedure. We propose the "tournedos" turnover de-epithelialized latissimus dorsi flap, which provides stable dermal and subdermal tissue that will not undergo atrophy over time over the dura. To reach an adequate aesthetic result, we used a uniform, unmeshed, thick split-thickness skin graft over the muscular portion of the tournedos flap. Patients who underwent this procedure, from March 1992 to March 2012, at McGill University Health Center and the Montreal Neurological Institute were included. Thirty-three complex microsurgical procedures for oncologic calvarial defect reconstructions were performed from March 1992 to March 2012. Among them, 6 patients benefited from the tournedos procedure. The average age was 74 years. Scalp defects sizes ranged from 4 × 10 to 16 × 18 cm (40-288 cm). All latissimus dorsi flap donor sites were closed primarily. Patients kept their donor-site drains for approximately 18 days (±5 days). One patient developed a seroma at the donor site after drain removal that was treated conservatively. All patients were satisfied with their reconstructions, and no secondary procedures were necessary. We present our most recent case with good photographic documentation. Our approach using the tournedos turnover de-epithelialized free flap provides durable and stable coverage for irradiated and/or previously infected calvarial defects. It is a safe procedure in those challenging complex cases and offers many advantages.

Porous Polyethylene Combined With Split Calvarial Bone Graft to Cover Complex Calvarial Defect

Various kinds of grafts, such as autogenous bone grafts and alloplastic materials, can be used for the reconstruction of calvarial defects. The selection of the optimum material for the repair of cranial defects is the greatest problem in the reconstruction of calvarial defects. For some complex calvarial defects, simple use of autogenous bone grafts or alloplastic materials makes functional and cosmetic reconstruction difficult to achieve. Therefore, the current study uses a new method to repair complex calvarial defects. Eight patients with complex calvarial defects underwent cranioplasty with porous polyethylene combined with split calvarial bone graft. Follow-up visits were conducted for 6 to 72 months to monitor the patients. Significant improvements in the contour of the skulls as well as in the aesthetic appearance of all the patients were observed. Moreover, no serious complications, such as infections, exposure, removal of the implants, and contour or implant abnormalities, were observed. Three cases displayed a transient extradural seroma collection, which was resolved through drainage and compression bandaging. The results of this pilot study indicate that the combined use of porous polyethylene and split calvarial bone graft may be useful for cranial reconstruction in patients with complex cranial defects.

Clinical Outcome of Cranioplasty With High-Density Porous Polyethylene

High-density porous polyethylene (Medpor) has long been used in cranioplasty and is still one of the best materials for calvarial reconstruction. Calvarial defects can be effectively reconstructed with fewer complications by using Medpor. This article reports our study on the use of Medpor in reconstructing calvarial defects. Twenty-three patients who underwent cranioplasty from 1999 to 2011 were included in this study. In all patients, Medpor was used for calvarial defect reconstruction, and all were followed up for at least 6 months. Most patients were satisfied with the reconstructive outcome. Only 1 patient had an infection and 1 had transient extradural seroma. All complications occurred within 2 years, and no new complications were found during the long-term follow-up. Using Medpor in cranioplasty is an effective method for reconstructing calvarial defects.

Decreased Rate of CSF Leakage Associated with Complete Reconstruction of Suboccipital Cranial Defects

Background Cerebrospinal fluid (CSF) leakage represents a major source of morbidity following microvascular decompression (MVD) surgery. The objective of this study was to retrospectively assess whether complete versus incomplete reconstruction of the suboccipital cranial defect influences the incidence of CSF leakage following MVD. Methods We reviewed the charts of 100 patients who consecutively underwent MVD for trigeminal neuralgia by two attending neurosurgeons between July 2004 and April 2010. Operative variables including incomplete or complete calvarial reconstruction, primary dural closure or dural closure with adjunct, and use of lumbar drainage were recorded. The effect of complete calvarial reconstruction on the incidence of postoperative CSF leakage was examined using a multivariate logistic regression model. Results Of the 36 patients whose wound closure was reconstructed with a complete cranioplasty, 2 (5.6%) patients experienced a postoperative CSF leak. Of the 64 patients whose wound closure was augmented with an incomplete cranioplasty, 15 (23.4%) experienced a postoperative CSF leak. There was suggestive but inconclusive evidence that the risk of CSF leakage following MVD was smaller with complete reconstruction of calvarial defect than with incomplete reconstruction (two-sided p value = 0.059), after accounting for age, dural closure method, use of lumbar drainage, and previous MVD. Conclusion Complete reconstruction of the suboccipital cranial defect decreases the risk of CSF leakage.

Customized Three Dimensional Printed Porous Polyethylene for Calvarial Reconstruction

Porous polyethylene has been widely used for cranio-maxillofacial procedures due to its highly stable, flexible and has been shown to exhibit rapid soft-tissue and bone ingrowth. Generally, it is available as standard shape which needs to be intra-operatively contoured and manually adapted to fit the defect of each patient. In this study, a technique of producing customized porous polyethylene implant for calvarial defect reconstruction was reported. The technique began with acquiring patients data by computed tomography and was three dimensionally reconstructed using a medical imaging software. The shape of implant was then digitally designed to fit the defect based on the patients anatomy and transferred to three dimensional printing machine to fabricate the implant using proprietary polyethylene formulation as raw material. This technique can be used to cover any cranial defect size, offering similar or even better cosmetic results to standard alloplast cranioplasty while decreasing operation time. This customized porous implant can permit ingrowth of tissue to increase interface stability, implant strength and decrease the risk of infection similarly to commercial product.

Angiogenesis and osteogenesis enhanced by bFGFex vivogene therapy for bone tissue engineering in reconstruction of calvarial defects

Reconstruction of bone defects by tissue engineered substitutes requires coordinated coupling between osteogenesis and angiogenesis. Basic fibroblast growth factor (bFGF or FGF-2) is a protein which acts actively in osteogenesis and angiogenesis during skeletal healing and development. It is hypothesized that BMSCs transfected with bFGF can directly stimulate regeneration of vascular tissue, and subsequently enhance osseous formation and remodeling after implantation of the tissue engineered bone. This study was designed to examine the impact of bFGF-BMSCs, seeded on nano-hydroxyapatite/polyamide66 (n-HA/PA66) composite scaffold, to enhance angiogenesis and osteogenesis in a calvarial critical-sized defect model in rats. To investigate the vascularization and bone formation of tissue engineered bone, the substrate was removed and processed for immunohistochemical, scanning electron microscopic examinations (SEM), reverse transcriptase-polymerase chain reaction (RT-PCR), dual energy X-ray absorptiometry (DEXA), microvessels counting, and new bone volume assay. The results demonstrate that bFGF mediated ex vivo gene transfer based on BMSCs can accelerate vascularization and bone regeneration on these composite scaffolds. The n-HA/PA66 scaffold combined with the bFGF-BMSCs may mimic the natural process of osteogenesis during repair of defect by tissue engineered bone.

An Experimental Design to Study Adipocyte Stem Cells for Reconstruction of Calvarial Defects

Autogenous osteogenic differentiated rat adipose stromal cells (ASCs) were used to repopulate cadaveric processed bone in a critical calvarial defect model to improve bone healing as compared with the standard treatment of cadaveric bone implantation alone. Forty-two skeletally mature Sprague-Dawley rats were randomized to 5 groups including bone graft only, bone/osteogenic differentiated ASCs, fibrin glue/osteogenic differentiated ASCs, and bone/fibrin glue/osteogenic differentiated ASCs; 2 animal calvarias were left empty. Adipose stromal cells were isolated from the inguinal fat pad of rats and differentiated into osteogenic cells, verified using von Kossa and alkaline phosphatase staining, and osteocalcin immunohistochemistry. These cells were added to sterilized, 8-mm cadaveric bone graft disks and placed back into calvarial defect for 6 weeks. The rat calvarias then underwent bone density analysis and histology. Intact cells were observed in the bone graft of the bone/osteogenic differentiated ASC group only. Islands of bone were seen in the bone-graft-only group, the bone/osteogenic differentiated ASC group, and the bone/fibrin/osteogenic differentiated ASC group. The bone-graft-only group and bone/osteogenic differentiated ASC group were similar in bone mineral density (1397 +/- 184.5 vs 1365 +/- 160.4). The bone/fibrin/osteogenic differentiated ASC group density was less than the bone and bone/osteogenic differentiated ASC groups at 835.2 +/- 319.5 (P < 0.001). Allograft bone scaffolds with autogenous osteogenic differentiated ASCs showed cellularity within the bone grafts and had larger bone islands. The presence of osteogenic differentiated ASCs did not increase overall bone density compared with bone graft only.

Reconstruction of calvarial defect of rabbits using porous calcium silicate bioactive ceramics

In this study, the in vivo bone-regenerative capacity and resorption of the porous β-calcium silicate (β-CaSiO 3, β-CS) bioactive ceramics were investigated in a rabbit calvarial defect model, and the results were compared with porous β-tricalcium phosphate (β-Ca 3(PO 4) 2, β-TCP) bioceramics. The porous β-CS and β-TCP ceramics were implanted in rabbit calvarial defects and the specimens were harvested after 4, 8 and 16 weeks, and evaluated by Micro-CT and histomorphometric analysis. The Micro-CT and histomorphometric analysis showed that the resorption of β-CS was much higher than that of β-TCP. The TRAP-positive multinucleated cells were observed on the surface of β-CS, suggesting a cell-mediated process involved in the degradation of β-CS in vivo. The amount of newly formed bone was also measured and more bone formation was observed with β-CS as compared with β-TCP ( p < 0.05). Histological observation demonstrated that newly formed bone tissue grew into the porous β-CS, and a bone-like apatite layer was identified between the bone tissue and β-CS materials. The present studies showed that the porous β-CS ceramics could stimulate bone regeneration and may be used as bioactive and biodegradable materials for hard tissue repair and tissue engineering applications.