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Our aim was to compare the osteogenic potential of mononuclear cells harvested from the iliac crest combined with bovine bone mineral (BBM) (experimental group) with that of autogenous cancellous bone alone (control group). We studied bilateral augmentations of the sinus floor in 6 adult sheep. BBM and mononuclear cells (MNC) were mixed and placed into one side and autogenous bone in the other side. Animals were killed after 8 and 16 weeks. Sites of augmentation were analysed radiographically and histologically. The mean (SD) augmentation volume was 3.0 (1.0) cm 3 and 2.7 (0.3) cm 3 after 8 and 16 weeks in the test group, and 2.8 (0.3) cm 3 (8 weeks) and 2.8 (1.2) cm 3 (16 weeks) in the control group, respectively. After 8 weeks, histomorphometric analysis showed 24 (3)% BBM, and 19 (11)% of newly formed bone in the test group. The control group had 20 (13%) of newly formed bone. Specimens after 16 weeks showed 29 (12%) of newly formed bone and 19 (3%) BBM in the test group. The amount of newly formed bone in the control group was 16 (6%). The results show that mononuclear cells, including mesenchymal stem cells, in combination with BBM as the biomaterial, have the potential to form bone.

In this in vitro study ovine osteoblast-like cells were cultured on seven different alloplastic biomaterials used for augmentation and for reconstruction of bone defects in dental and craniomaxillofacial surgery. The aim of this study was to examine the growth behaviour (viability, cell density and morphology) of ovine osteoblast-like cells on the investigated biomaterials to get knowledge which biomaterial is qualified to act as a cell carrier system in further in vivo experiments. The biomaterials were either synthetically manufactured or of natural origin. As synthetically manufactured biomaterials Ethisorb®, MakroSorb®, Palacos®R, and PDS® film were used. As biomaterials of natural origin Beriplast®P, Bio-Oss® and Titanmesh were investigated. The cell proliferation and cell colonization were analyzed by a proliferation assay and scanning electron microscopy. Osteoblast-like cells proliferated and attached on all biomaterials, except on Beriplast®. On Ethisorb® the highest cell proliferation rate was measured followed by Palacos®R. Both biomaterials offer suitable growth and proliferation conditions for ovine osteoblast-like cells. The proliferation rates of Bio-Oss®, MakroSorb®, PDS®-film and Titanmesh were low and SEM examinations of these materials showed less spread osteoblast-like cells. The results showed that ovine osteoblast-like cells appear to be sensitive to substrate composition and topography. This in vitro study provides the basis for further in vivo studies using the sheep model to examine the biocompatibility and the long-term interaction between the test material and tissue (bone regeneration).

Angiogenesis is a cascade-like mechanism which is essential for tumour growth and metastasis. Therefore the existence of angiogenic molecules and the density of activated endothelial cells in individual tumours is of major interest. MATERIAL/PATIENTS: In order to evaluate the prognostic significance of these molecules, the distribution pattern was studied of vascular endothelial growth factor (VEGF) and activated endothelial cells in tumours and normal, healthy oral mucosal specimens from 51 consecutive patients with primary oral squamous cell carcinoma.Frozen sections (vascular endothelial growth factor) and paraffin-embedded sections (endoglin, CD105) were investigated quantitatively by immunohistochemistry. The Pearson correlation, the non-parametric Mann-Whitney test, the non-parametric Wilcoxon rank sum test with multiple comparisons and the non-parametric Kruskal-Wallis test with multiple comparisons were used for statistical analyses.Endoglin expression in tumour tissue was significantly higher than in normal healthy mucosa (P0.001). T1 tumours showed a significantly lower staining for endoglin compared with T2, T3 and T4 tumours but there was no increase with each T stage. No statistical correlation was found between VEGF expression and endoglin staining.Even though there is controversy about the prognostic relevance of VEGF, our results suggest that the factor is not suitable to decide prognosis in oral cancer. Endoglin may have a significant role in the development of squamous cell carcinoma of the oral cavity and might be relatively more specific than commonly used endothelial markers.

The aim of this study was to investigate the osteogenic effect of three different cell-seeded 3D-bioplotted scaffolds in a ovine calvarial critical-size defect model. The choice of scaffold-materials was based on their applicability for 3D-bioplotting and respective possibility to produce tailor-made scaffolds for the use in cranio-facial surgery for the replacement of complex shaped boneparts. Scaffold raw-materials are known to be osteoinductive when being cell-seeded [poly(L-lactide-co-glycolide) (PLGA)] or having components with osteoinductive properties as tricalciumphosphate (TCP) or collagen (Col) or chitosan. The scaffold-materials PLGA, TCP/Col, and HYDR (TCP/Col/chitosan) were cell-seeded with osteoblast-like cells whether gained from bone (OLB) or from periost (OLP). In a prospective and randomized design nine sheep underwent osteotomy to create four critical-sized calvarial defects. Three animals each were assigned to the HYDR-, the TCP/Col-, or the PLGA-group. In each animal, one defect was treated with a cell-free, an OLB- or OLP-seeded group-specific scaffold, respectively. The fourth defect remained untreated as control (UD). Fourteen weeks later, animals were euthanized for histo-morphometrical analysis of the defect healing. OLB- and OLP-seeded HYDR and OLB-seeded TCP/Col scaffolds significantly increased the amount of newly formed bone (NFB) at the defect bottom and OLP-seeded HYDR also within the scaffold area, whereas PLGA-scaffolds showed lower rates. The relative density of NFB was markedly higher in the HYDR/OLB group compared to the corresponding PLGA group. TCP/Col had good stiffness to prepare complex structures by bioplotting but HYDR and PLGA were very soft. HYDR showed appropriate biodegradation, TCP/Col and PLGA seemed to be nearly undegraded after 14 weeks. 3D-bioplotted, cell-seeded HYDR and TCP/Col scaffolds increased the amount of NFB within ovine critical-size calvarial defects, but stiffness, respectively, biodegradation of materials is not appropriate for the application in cranio-facial surgery and have to be improved further by modifications of the manufacturing process or their material composition.

New reconstructive and less invasive methods have been searched to optimize bone formation and osseointegration of dental implants in maxillary sinus augmentation.The aim of the presented ovine split-mouth study was to compare bovine bone mineral (BBM) alone and in combination with mesenchymal stem cells (MSCs) regarding their potential in sinus augmentation.Bilateral sinus floor augmentations were performed in six adult sheep. BBM and MSCs were placed into the test side and only BBM in the contra-lateral control side of each sheep. Animals were sacrificed after 8 and 16 weeks. Augmentation sites were analyzed by computed tomography, histology, and histomorphometry.The initial volumes of both sides were similar and did not change significantly with time. A tight connection between the particles of BBM and the new bone was observed histologically. Bone formation was significantly (p = 0.027) faster by 49% in the test sides.The combination of BBM and MSCs accelerated new bone formation in this model of maxillary sinus augmentation. This could allow early placement of implants.

Objective To compare new bone formation in maxillary sinus augmentation procedures using biomaterial associated with mesenchymal stem cells (MSCs) separated by two different isolation methods. Background In regenerative medicine open cell concentration systems are only allowed for clinical application under good manufacturing practice conditions. Methods Mononuclear cells, including MSCs, were concentrated with either the synthetic polysaccharide (FICOLL) method (classic open system--control group, n = 6 sinus) or the bone marrow aspirate concentrate (BMAC) method (closed system--test group, n = 12 sinus) and transplanted in combination with biomaterial. A sample of the cells was characterized by their ability to differentiate. After 4.1 months (SD +/- 1.0) bone biopsies were obtained and analyzed. Results The new bone formation in the BMAC group was 19.9% (90% confidence interval [CI], 10.9-29), and in the FICOLL group was 15.5% (90% CI, 8.6-22.4). The 4.4% difference was not significant (90% CI, -4.6-13.5; p = 0.39). MSCs could be differentiated into osteogenic, chondrogenic, and adipogenic lineages. Conclusion MSCs harvested from bone marrow aspirate in combination with bovine bone matrix particles can form lamellar bone and provide a reliable base for dental implants. The closed BMAC system is suited to substitute the open FICOLL system in bone regeneration procedures.