Additively manufactured biphasic construct loaded with BMP-2 for vertical bone regeneration: A pilot study in rabbit

Biphasic scaffolds have gained increasing attention for the regeneration of osteochondral interfacial tissue because they are expected to effectively define the interfacial structure of tissue that comprises stratified cartilage with a degree of calcification. Here, we propose a biphasic nanofiber construct made of poly(lactide-co-caprolactone) (PLCL) and its mineralized form (mPLCL) populated with cells. Primary rat articular chondrocytes (ACs) and bone marrow-derived mesenchymal stem cells (MSCs) were cultured on the layers of bare PLCL and mPLCL nanofibers, respectively, for 7 days, and the biphasic cell-nanofiber construct was investigated at 4 weeks after implantation into nude mice. Before implantation, the ACs and MSCs grown on each layer of PLCL and mPLCL nanofibers exhibited phenotypes typical of chondrocytes and osteoblasts, respectively, under proper culture conditions, as analyzed by electron microscopy, histological staining, cell growth kinetics, and real-time polymerase chain reaction. The biphasic constructs also showed the development of a possible formation of cartilage and bone tissue in vivo. Results demonstrated that the cell-laden biphasic nanofiber constructs may be useful for the repair of osteochondral interfacial tissue structure.

Event Abstract Back to Event Multiphasic constructs and cell sheet technology in the context of periodontal regeneration Cedryck Vaquette1, Saso Ivanovski2 and Dietmar Werner Hutmacher1 1 Queensland University of Technology, Institute of Health and Biomedical Innovation, Australia 2 Griffith University, School of Dentistry and Oral Health, Menzies Health Institute Queensland, Australia Introduction: Periodontitis is a common chronic inflammatory disease that results in degradation of the supporting structures around teeth and in severe cases can lead to tooth loss. Current surgical treatments such as Guided Tissue Regeneration (GTR) are efficient at limiting the progression of the disease by controlling the inflammatory aspect of periodontitis but regeneration is not commonly achieved. Our groups have developed a tissue engineering strategy involving the utilisation of cell sheets combined with biphasic biomaterial scaffolds in order to enhance the regenerative capacity of GTR. The biphasic structures, composed of a bone and periodontal compartments, are specifically designed to recapitulate the highly organised and hierarchical architecture of the native periodontium composed of cementum, periodontal ligament, alveolar bone and gingival tissue. This paper provides an overview of the research we have performed in this area along with our latest advancements. Materials and Methods: Several generations of polycaprolactone (PCL) biphasic constructs were developed combining additive manufacturing methodologies such as Fused Deposition Modelling (FDM), solution electrospinning and Melt Electrospinning Writing (MEW). Our most recent research has resulted in the development of a fibre guiding scaffold manufactured by MEW for the bone compartment and by nanofabrication technologies for the creation aligned silk fibroin micro-channels for the periodontal compartment. Our constructs have been tested in vitro and in vivo into rodent and ovine models while testing several architectures and cell sources (gingival fibroblasts, periodontal ligament fibroblasts, and bone marrow mesenchymal stem cells). Results and Discussion: We have demonstrated that our biphasic scaffolds fulfilled the requirements for GTR; wound stabilisation, space maintenance and selective cell repopulation, and were capable of regenerating fraction or entire portion of the periodontium complex in a rodent ectopic model and in a surgically created periodontal one model. The presence of the cell sheets was also essential for the improved regeneration of the targeted organ. The incorporation of aligned channels into the biphasic scaffold design resulted in guiding the orientation of the newly formed periodontal ligament fibres. Conclusion: The development of multicompartment scaffolds for periodontal regeneration has been proven as an effective strategy when combined with cell delivery. Further to the delivery of cells, tissue guidance provided by topographical clues, is also essential and resulted in a physiologically relevant attachment of the newly formed periodontal fibres. Keywords: Regenerative Medicine, 3D scaffold, complex tissue orgnization, cell sheeting Conference: 10th World Biomaterials Congress, Montréal, Canada, 17 May - 22 May, 2016. Presentation Type: New Frontier Oral Topic: Combinatorial approaches to biomaterial design Citation: Vaquette C, Ivanovski S and Hutmacher D (2016). Multiphasic constructs and cell sheet technology in the context of periodontal regeneration. Front. Bioeng. Biotechnol. Conference Abstract: 10th World Biomaterials Congress. doi: 10.3389/conf.FBIOE.2016.01.00904 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 27 Mar 2016; Published Online: 30 Mar 2016. Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Cedryck Vaquette Saso Ivanovski Dietmar Werner Hutmacher Google Cedryck Vaquette Saso Ivanovski Dietmar Werner Hutmacher Google Scholar Cedryck Vaquette Saso Ivanovski Dietmar Werner Hutmacher PubMed Cedryck Vaquette Saso Ivanovski Dietmar Werner Hutmacher Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Fabrication of 3D melt electrowritting multiphasic scaffold with bioactive and osteoconductivite functionalities for periodontal regeneration

To address the problem of insufficient bone mass in the implant area, we focused on the vertical increment of the posterior mandibular area to increase bone mass with the aid of a healing abutment. Data of patients with insufficient vertical bone height in the posterior mandibular area were collected, and vertical increment of alveolar bone operations was performed with the aid of a healing abutment. Preoperative residual alveolar bone height, immediate postoperative alveolar bone height, and 6-month postoperative alveolar bone height were recorded, with peri-implant soft tissue results 6 months after surgery using the modified plaque index and sulcus bleeding index. Twelve patients, aged 42-73 years, with an average age of 55.91 ± 11.58 years, received vertical bone augmentation in the posterior mandibular region supported by implant healing abutments. Fifteen SLA TSIII OSSTEM implants were utilized in the 12 patients; one patient failed in vertical bone augmentation at one site (H0 = 0 mm). The vertical bone augmentation effect of two patients at two sites was 0 mm < H0 < 1 mm, and the vertical bone augmentation effect of 12 sites in nine patients was H0 ≥ 1 mm. The implant success rate was 93.3%, and the mean vertical bone gain was 2.91 mm. Peri-implant soft tissue parameters are as follows: mean modified plaque index, 1.92; mean modified sulcus bleeding index, 1.21; and mean probing depth, 3.18. No clinically observable complications occurred. Bone augmentation supported by the implant healing abutment showed the characteristics of "platform transfer", with good formation of the implant-bone interface. The bone augmentation surgery was completed at the same time as the implant placement, which reduced the pain of multiple operations and shortened waiting times. We provide a novel idea to solve the problem of insufficient vertical bone height in the posterior mandibular region.

This study reports on the development of an additively manufactured polycaprolactone (PCL) biphasic scaffold for achieving vertical bone augmentation. The biphasic scaffold consisted of a space maintaining 3D-printed outer shell into which a highly porous melt electrospinning writing membrane was inserted. This emulated the architectural arrangement of the native jawbone composed by the cortical plate and alveolar bone. The biphasic scaffold was further functionalised with a heparinised hyaluronic acid/gelatine hydrogel containing Bone Morphogenetic Protein-2. Its performance with respect to vertical bone augmentation was assessed in an extraskeletal ovine model. For the purposes of comparison, 7 different groups were implanted for 8 weeks under a polymeric protective dome: Empty, Biphasic scaffold with the hydrogel (PCL-Gel), PCL-Gel with 75 or 150 μg of BMP-2 (PCL-BMP-75 and PCL-BMP-150), hydrogel (Gel), Gel containing 75 or 150 μg of BMP-2 (Gel-BMP-75 and Gel-BMP-150). This resulted in more bone formation in the elevated space in the BMP-2 containing groups, particularly the PCL-BMP specimens, whereby full height was achieved as measured by micro-computed tomography and histology. Interestingly, there was no significant bone volume increase with the higher dose of BMP-2. In a separate cohort of animals previously implanted with 2 samples of the Gel-BMP-150 and PCL-BMP-150 groups, a surgical re-entry at 8 weeks of healing was performed. The protective domes were removed, and one implant was placed on one specimen per group. Bone stability of the augmented bone structure was assessed at 8 weeks and demonstrated that the biphasic scaffold prevented bone resorption, whereas the hydrogel underwent extensive vertical bone loss. This was attributed to the space maintenance properties of the biphasic scaffold.

BackgroundAlveolar ridge augmentations are challenging procedures in dental implantology, especially in esthetic zone. 3D alveolar defects can be treated by guided bone regeneration (GBR), distraction osteogenesis, or bone blocks. This study introduces a new technique for 3D-alveolar ridge augmentation by using L-shape autogenous symphyseal bone block.PurposeThis study aimed to assess both horizontal and vertical alveolar bone augmentation for severe atrophied anterior maxilla and mandible, using an L- shape autogenous bone block harvested from the symphysis.Patients and methodelven partially edentulous patients who needed horizontal and vertical bone augmentation in the anterior maxilla or mandible before implant placement were selected for this study. For each patient, an autogenous bone block was harvested from the symphysis, trimmed to L-shape, and used to augment the anterior maxilla or mandible horizontally and vertically. Horizontal and vertical bone gain was measured by CBCT immediate postoperative and at 6months postoperatively.ResultsIn this study, 14 L-shape bone blocks were grafted in 11 patients. The patients were 4males and 7females, with a mean age of 24.63years. Healing was uneventful for all patients with no sensory disturbance. The Mean of horizontal bone gain was 4.17 ± 0.77 mm immediate postoperative, and was 3.52 ± 0.75 after 6months. While, the mean of vertical bone gain was 6.51 ± 1.01 mm immediate postoperative, and was 4.74 ± 1.03after 6months. The mean of horizontal and vertical bone loss was 0.74 ± 0.24 mm and 1.62 ± 0.19 mm after 6 months, respectively.ConclusionUsing L- shape autogenous bone block harvested from the symphysis for alveolar ridge augmentation is a safe, predictable and effective method for 3D ridge augmentation.

To evaluate the efficacy of 3D-printed scaffolds that were osteoinductively functionalized with a bone morphogenetic protein 2 (BMP-2)-incorporated biomimetic calcium phosphate particles (BMP-2-inc. BpNcCaP)/hyaluronic acid (HA) composite gel in vertical bone augmentation in beagle dogs. Four Beagle dogs were used in this study. Three months after the extraction of 1st, 2nd, 3rd, and 4th premolars at both sides of the lower jaws of Beagle dogs, one or two critical-size vertical bone defects (4 mm vertical bone defect without buccal and lingual bone) on each sidewere surgically created. The defects were randomly subjected to the following groups: (1) Control (without bone-defect-filling materials); (2) 3D scaffold; (3) BMP2-inc. BpNcCaP/HA-functionalized 3D scaffold. Six weeks post-surgery, samples were harvested and subjected to micro-CT and histomorphometric analyses. The struts of the BMP2-inc. BpNcCaP/HA-func. 3D scaffold were covered by a thick layer of cemented irregular particles with an average pore size at 327 ± 27 μm. The BpNcCaP/HA-func. 3D scaffold group bore significantly higher bone volume, bone volume fraction, trabecular number, trabecular thickness, bone mineral density, connectivity density, and bone volumes in three directions (mesiodistal, buccolingual, and apicocoronal) when compared with the groups of Control and 3D scaffold. Moreover, the BMP2-inc. BpNcCaP/HA-func. 3D scaffold group bore significantly lower trabecular separation and exhibited significantly higher bone-to-scaffold contact percentage and newly formed bone area percentage within pores in comparison with 3D scaffold. BMP2-inc. BpNcCaP/HA-func. 3D scaffold dramatically enhanced vertical alveolar bone augmentation, which suggests a promising application potential of BMP2-inc. BpNcCaP/HA-func. 3D scaffold in dental clinic.

The purpose of this study was to evaluate the vertical new bone formation induced by sputtered HA-coated titanium implants (HA-coated) compared with sandblasted acid-etched titanium implants (noncoated) in a rabbit calvarial model. Twenty HA-coated and 20 noncoated titanium implants were divided equally into four groups as HA-coated implant (HA); noncoated implant (NC); HA-coated implant with membrane (HA/M); noncoated implant with membrane (NC/M). All implants were placed 5 mm above the original bone (OB). Collagen membranes were placed over the implants in HA/M and NC/M groups. The animals were sacrificed at 4 weeks (n = 5) and 8 weeks (n = 5). Vertical bone height above OB (VBH, mm) and augmented bone area (ABA, mm(2) ) were analyzed histologically and radiographically. At 4 weeks, VBH reached significantly higher level in HA/M group compared with other three groups (p < 0.05). At 8 weeks, significant difference was detected between HA/M and NC groups (p < 0.05). At 4 and 8 weeks, ABA in HA/M group was significantly larger compared with other three groups (p < 0.05). The present results indicated that sputtered HA-coated titanium implant together with collagen membrane could be a novel and effective approach for vertical bone augmentation.

Objective: Guided bone regeneration (GBR) for vertical bone augmention is an easy-to-implement approach and has a good prognosis. However, there are many different procedures that lead to different clinical outcomes. The use of platelet-rich fibrin (PRF) can improve outcomes in regenerative treatments. Therefore, this study aimed to evaluate the effectiveness of vertical bone grafting by guided bone reconstruction with titanium-reinforced PTFE membrane combined with PRF. Materials and Methods: Nine patients who come to the Department of Odonto-Stomatology, University of Medicine and Pharmacy, Ho Chi Minh City, have a need for implant treatment and have mild to moderate vertical bone deficiency. Patients are treated with bone grafting by GBR technique: using a mixture of bone grafts including autogenous bone and deproteinized bovine bone (Geistlich Bio-Oss) at a ratio of 1:1, mixed with injectable form PRF in the form of sticky bone. The vertical bone defects were protected by a titanium-reinforced d-PTFE membrane and covered by an A-PRF+ membrane. The bone gain was measured using a cone-beam computed tomography at baseline and after a period of 8 months. Results: Analyzing the research results on 9 patients, 15 research units corresponding to 15 bone grafting sites, the GBR procedures an increase in bone height (p &lt; 0,05) after treatment. In the two-staged approach, the vertical bone gain was 3.97 ± 0.92 mm; in the group of simultaneous one-staged procedure, the vertical bone gain was 3.89 ± 1.13 mm. In general, the bone height of the study sample achieved an average of 94.16 ± 10.7% compared to the ideal bone height. Conclusion: GBR technique using a mixture of particulate autogenous bone and xenogenous bone and PRF is effective for vertical bone augmentation in maxillary and mandibular regions, ensuring favorable bone morphology, permitting sufficient bone gain to future implant placement and prosthetics.

This study evaluated the quantity and quality of newly formed vertical bone induced by sputtered hydroxyapatite-coated titanium implants compared with sandblasted acid-etched implants after dura mater elevation. Hydroxyapatite-coated and non-coated implants (n = 20/group) were used and divided equally into two groups. All implants were randomly placed into rabbit calvarial bone (four implants for each animal) emerging from the inferior cortical layer, displacing the dura mater 3 mm below the original bone. Animals were sacrificed at 4 (n = 5) and 8 (n = 5) weeks post-surgery. Vertical bone height and area were analyzed histologically and radiographically below the original bone. Vertical bone formation was observed in both groups. At 4 and 8 weeks, vertical bone height reached a significantly higher level in the hydroxyapatite compared with the non-coated group (p < 0.05). Vertical bone area was significantly larger in the hydroxyapatite compared with the non-coated group at 4 and 8 weeks (p < 0.05). This study indicates that vertical bone formation can be induced by dura mater elevation and sputtered hydroxyapatite coating can enhance vertical bone formation.

The optimal microarchitecture of 3D-printed β-TCP bone substitutes for vertical bone augmentation differs from that for osteoconduction

The management of facial defects has rapidly changed in the last decade. Functional and esthetic requirements have steadily increased along with the refinements of surgery. In the case of advanced atrophy or jaw defects, extensive horizontal and vertical bone augmentation is often unavoidable to enable patients to be fitted with implants. Loss of vertical alveolar bone height is the most common cause for a non primary stability of dental implants in adults. At present, there is no ideal therapeutic approach to cure loss of vertical alveolar bone height and achieve optimal pre-implantological bone regeneration before dental implant placement. Recently, it has been found that specific populations of stem cells and/or progenitor cells could be isolated from different dental resources, namely the dental follicle, the dental pulp and the periodontal ligament. Our research group has cultured palatal-derived stem cells (paldSCs) as dentospheres and further differentiated into various cells of the neuronal and osteogenic lineage, thereby demonstrating their stem cell state. In this publication will be shown whether paldSCs could be differentiated into the osteogenic lineage and, if so, whether these cells are able to regenerate alveolar bone tissue in vivo in an athymic rat model. Furthermore, using these data we have started a proof of principle clinical- and histological controlled study using stem cell-rich palatal tissues for improving the vertical alveolar bone augmentation in critical size defects. The initial results of the study demonstrate the feasibility of using stem cell-mediated tissue engineering to treat alveolar bone defects in humans.

This study aimed to evaluate the effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) on vertical bone regeneration of edentulous ridge. Bilateral upper first and second molars of 8-week-old Wistar rats were extracted and the ridges were allowed to heal for 3 weeks. Compressed poly(lactic-co-glycolic acid) copolymer/gelatin sponge (PGS) was used as a carrier of rhBMP-2. PGS alone (control group) or PGS with 5 mug rhBMP-2 (test group) was implanted at the top part of alveolar ridge. The sham group received no implantation. The rats were killed at 1, 2, 4, 8 and 12 weeks after implantation and examined histologically and histomorphometrically. In the test group, significant bone augmentation was evident on the alveolar ridge throughout the experimental period. Histomorphometric analysis revealed greater tissue volume and height of alveolar bone in the test group compared with the control and sham groups (P < 0.05) from 4 weeks onward and the augmented tissues (5 mm3 in tissue volume and 1.5 mm in bone height) were maintained until 12 weeks. Osteoblast surface increased at 2 and 4 weeks and osteoid thickness reached a peak (25 microm) at 2 weeks. Dynamic variables, which represented calcification, were higher in the test group than the control and sham groups at 4 and 8 weeks (P < 0.05). These results suggest that use of rhBMP-2/PGS may achieve vertical bone augmentation, and stabilizes denture prosthesis or makes up for inadequate bone mass for implant prosthesis.

BackgroundSufficient vertical and lateral bone supply and a competent osteogenic healing process are prerequisities for the successful osseointegration of dental implants in the alveolar bone. Several techniques including autologous bone grafts and guided bone regeneration are applied to improve quality and quantity of bone at the implantation site. Depending on the amount of lacking bone one- or two-stage procedures are required. Vertical bone augmentation has proven to be a challenge particularly in terms of bone volume stability. This study focuses on the three dimensional vertical bone generation in a one stage procedure in vivo. Therefore, a collagenous disc-shaped scaffold (ICBM = Insoluble Collagenous Bone Matrix) containing rhBMP-2 (Bone Morphogenetic Protein-2) and/or VEGF (Vascular Endothelial Growth Factor) was applied around the coronal part of a dental implant during insertion. RhBMP-2 and VEGF released directly at the implantation site were assumed to induce the generation of new vertical bone around the implant.MethodsOne hundred eight titanium implants were inserted into the mandible and the tibia of 12 mini pigs. Four experimental groups were formed: Control group, ICBM, ICBM + BMP-2, and ICBM + BMP-2 + VEGF.After 1, 4 and 12 weeks the animals were sacrificed and bone generation was investigated histologically and histomorphometrically.ResultsAfter 12 weeks the combination of ICBM + rhBMP2 + VEGF showed significantly more bone volume density (BVD%), a higher vertical bone gain (VBG) and more vertical bone gain around the implant (PVBG) in comparison to the control group.ConclusionBy using collagenous disc-shaped matrices in combination with rhBMP-2 and VEGF vertical bone can be generated in a one stage procedure without donor site morbidity. The results of the presenting study suggest that the combination of rhBMP-2 and VEGF applied locally by using a collagenous carrier improves vertical bone generation in vivo. Further research is needed to establish whether this technique is applicable in clinical routines.

Vertical bone augmentation is aimed at regenerating bone extraskeletally (outside the skeletal envelope) in order to increase bone height. It is generally required in the case of moderate to severe atrophy of bone in the oral cavity due to tooth loss, trauma, or surgical resection. Currently utilized surgical techniques, such as autologous bone blocks, distraction osteogenesis, and Guided Bone Regeneration (GBR), have various limitations, including morbidity, compromised dimensional stability due to suboptimal resorption rates, poor structural integrity, challenging handling properties, and/or high failure rates. Additive manufacturing (3D printing) facilitates the creation of highly porous, interconnected 3-dimensional scaffolds that promote vascularization and subsequent osteogenesis, while providing excellent handling and space maintaining properties. This review describes and critically assesses the recent progress in additive manufacturing technologies for scaffold, membrane or mesh fabrication directed at vertical bone augmentation and Guided Bone Regeneration and their in vivo application.