Repair of critical-size porcine craniofacial bone defects using a collagen-polycaprolactone composite biomaterial

Regenerative medicine approaches for massive craniomaxillofacial bone defects face challenges associated with the scale of missing bone, the need for rapid graft-defect integration, and challenges related to inflammation and infection. Mineralized collagen scaffolds have been shown to promote mesenchymal stem cell osteogenesis due to their porous nature and material properties, but are mechanically weak, limiting surgical practicality. Previously, these scaffolds were combined with 3D-printed polycaprolactone mesh to form a scaffold-mesh composite to increase strength and promote bone formation in sub-critical sized porcine ramus defects. Here, we compare the performance of mineralized collagen-polycaprolactone composites to the polycaprolactone mesh in a critical-sized porcine ramus defect model. While there were no differences in overall healing response between groups, our data demonstrated broadly variable metrics of healing regarding new bone infiltration and fibrous tissue formation. Abscesses were present surrounding some implants and polycaprolactone polymer was still present after 9-10 months of implantation. Overall, while there was limited successful healing, with 2 of 22 implants showed substantial levels of bone regeneration, and others demonstrating some form of new bone formation, the results suggest targeted improvements to improve repair of large animal models to more accurately represent craniomaxillofacial bone healing. Notably, strategies to increase osteogenesis throughout the implant, modulate the immune system to support repair, and employ shape-fitting tactics to avoid implant micromotion and resultant fibrosis. Improvements to the mineralized collagen scaffolds involve changes in pore size and shape to increase cell migration and osteogenesis and inclusion or delivery of factors to aid vascular ingrowth and bone regeneration.

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Inclusion of a 3D-printed Hyperelastic bone mesh improves mechanical and osteogenic performance of a mineralized collagen scaffold

10.1101/2020.06.26.171835 ◽

2020 ◽

Author(s):

Marley J. Dewey ◽

Andrey V. Nosatov ◽

Kiran Subedi ◽

Ramille Shah ◽

Adam Jakus ◽

...

Keyword(s):

Mechanical Performance ◽

Negative Impact ◽

Collagen Scaffold ◽

Collagen Scaffolds ◽

Shape Fitting ◽

Cell Processes ◽

3D Printed ◽

Future Work ◽

Mineralized Collagen

ABSTRACTRegenerative repair of craniomaxillofacial bone injuries is challenging due to both the large size and irregular shape of many defects. Mineralized collagen scaffolds have previously been shown to be a promising biomaterial implant to accelerate craniofacial bone regeneration in vivo. Here we describe inclusion of a 3D-printed polymer or ceramic-based mesh into a mineralized collagen scaffold to improve mechanical and biological activity. Mineralized collagen scaffolds were reinforced with 3D-printed Fluffy-PLG (ultraporous polylactide-co-glycolide co-polymer) or Hyperelastic Bone (90wt% calcium phosphate in PLG) meshes. We show degradation byproducts and acidic release from the printed structures have limited negative impact on the viability of mesenchymal stem cells. Further, inclusion of a mesh formed from Hyperelastic Bone generates a reinforced composite with significantly improved mechanical performance (elastic modulus, push-out strength). Composites formed from the mineralized collagen scaffold and either Hyperelastic Bone or Fluffy-PLG reinforcement both supported human bone-marrow derived mesenchymal stem cell osteogenesis and new bone formation. Strikingly, composites reinforced with Hyperelastic Bone mesh elicited significantly increased secretion of osteoprotegerin, a soluble glycoprotein and endogenous inhibitor of osteoclast activity. These results suggest that architectured meshes can be integrated into collagen scaffolds to boost mechanical performance and actively instruct cell processes that aid osteogenicity; specifically, secretion of a factor crucial to inhibiting osteoclast-mediated bone resorption. Future work will focus on further adapting the polymer mesh architecture to confer improved shape-fitting capacity as well as to investigate the role of polymer reinforcement on MSC-osteoclast interactions as a means to increase regenerative potential.

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In vivo Evaluation of a Collagen Scaffold Preconditioned with Adipose-derived Mesenchymal Stem Cells Used for Bone Regeneration A histological study

Materiale Plastice ◽

10.37358/mp.18.4.5102 ◽

2018 ◽

Vol 55 (4) ◽

pp. 691-695

Author(s):

Tudor Sorin Pop ◽

Anca Maria Pop ◽

Alina Dia Trambitas Miron ◽

Klara Brinzaniuc ◽

Simona Gurzu ◽

...

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

Bone Regeneration ◽

Histological Study ◽

Collagen Scaffold ◽

Bone Defects ◽

Collagen Scaffolds ◽

In Vivo Evaluation ◽

Calvarial Bone ◽

Bone Apposition

The use of collagen scaffolds and stem cells for obtaining a tissue-engineering complex has been an important concept in promoting repair and regeneration of the bone tissue. Such units represent important steps in the development of an ideal scaffold-cell complex that would sustain new bone apposition. The aim of our study was to perform a histologic evaluation of the healing of critical-sized bone defects, using a biologic collagen scaffold with adipose-derived mesenchymal stem cells, in comparison to negative controls created in the adjacent bone. We used 16 Wistar rats and according to the study design 2 calvarial bone defects were created in each animal, one was filled with collagen seeded with adipose-derived stem cells and the other one was considered negative control. During the following month, at weekly intervals, the animals were euthanized and the specimens from bone defects were histologically evaluated. The results showed that these scaffolds were highly biocompatible as only moderate inflammation no rejection reactions were observed. Furthermore, the first signs of osseous healing appeared after two weeks accompanied by angiogenesis. Collagen scaffolds seeded with adipose-derived mesenchymal stem cells can be considered a promising treatment option in bone regeneration of large defects.

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Longitudinal in vivo evaluation of bone regeneration by combined measurement of multi-pinhole SPECT and micro-CT for tissue engineering

Scientific Reports ◽

10.1038/srep10238 ◽

2015 ◽

Vol 5 (1) ◽

Cited By ~ 16

Author(s):

Philipp S. Lienemann ◽

Stéphanie Metzger ◽

Anna-Sofia Kiveliö ◽

Alain Blanc ◽

Panagiota Papageorgiou ◽

...

Keyword(s):

Computed Tomography ◽

High Resolution ◽

Bone Formation ◽

Bone Regeneration ◽

Bone Defects ◽

Histological Evaluation ◽

Biological Processes ◽

Micro Ct ◽

Pinhole Spect

Abstract Over the last decades, great strides were made in the development of novel implants for the treatment of bone defects. The increasing versatility and complexity of these implant designs request for concurrent advances in means to assess in vivo the course of induced bone formation in preclinical models. Since its discovery, micro-computed tomography (micro-CT) has excelled as powerful high-resolution technique for non-invasive assessment of newly formed bone tissue. However, micro-CT fails to provide spatiotemporal information on biological processes ongoing during bone regeneration. Conversely, due to the versatile applicability and cost-effectiveness, single photon emission computed tomography (SPECT) would be an ideal technique for assessing such biological processes with high sensitivity and for nuclear imaging comparably high resolution (<1 mm). Herein, we employ modular designed poly(ethylene glycol)-based hydrogels that release bone morphogenetic protein to guide the healing of critical sized calvarial bone defects. By combined in vivo longitudinal multi-pinhole SPECT and micro-CT evaluations we determine the spatiotemporal course of bone formation and remodeling within this synthetic hydrogel implant. End point evaluations by high resolution micro-CT and histological evaluation confirm the value of this approach to follow and optimize bone-inducing biomaterials.

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3D-printed Poly-Lactic Co-Glycolic Acid (PLGA) scaffolds in non-critical bone defects impede bone regeneration in rabbit tibia bone

Bio-Medical Materials and Engineering ◽

10.3233/bme-216017 ◽

2021 ◽

pp. 1-7

Author(s):

Jin Xi Lim ◽

Min He ◽

Alphonsus Khin Sze Chong

Keyword(s):

Computed Tomography ◽

Bone Regeneration ◽

Bone Defect ◽

Volume Ratio ◽

Bone Defects ◽

Control Group ◽

Micro Computed Tomography ◽

Rabbit Tibia ◽

3D Printed ◽

Critical Bone Defects

BACKGROUND: An increasing number of bone graft materials are commercially available and vary in their composition, mechanism of action, costs, and indications. OBJECTIVE: A commercially available PLGA scaffold produced using 3D printing technology has been used to promote the preservation of the alveolar socket after tooth extraction. We examined its influence on bone regeneration in long bones of New Zealand White rabbits. METHODS: 5.0-mm-diameter circular defects were created on the tibia bones of eight rabbits. Two groups were studied: (1) control group, in which the bone defects were left empty; (2) scaffold group, in which the PLGA scaffolds were implanted into the bone defect. Radiography was performed every two weeks postoperatively. After sacrifice, bone specimens were isolated and examined by micro-computed tomography and histology. RESULTS: Scaffolds were not degraded by eight weeks after surgery. Micro-computed tomography and histology showed that in the region of bone defects that was occupied by scaffolds, bone regeneration was compromised and the total bone volume/total volume ratio (BV/TV) was significantly lower. CONCLUSION: The implantation of this scaffold impedes bone regeneration in a non-critical bone defect. Implantation of bone scaffolds, if unnecessary, lead to a slower rate of fracture healing.

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Evaluation of the Long-Term Results of Rat Cranial Bone Repair Using a Particular Xenograft

Journal of Oral Implantology ◽

10.1563/aaid-joi-d-09-00064 ◽

2010 ◽

Vol 36 (3) ◽

pp. 167-173 ◽

Cited By ~ 5

Author(s):

Hakan Develioglu ◽

SerpilÜnver Saraydın ◽

Ünal Kartal ◽

Levent Taner

Keyword(s):

Bone Formation ◽

Bone Repair ◽

Fibrous Tissue ◽

Bone Defects ◽

Parietal Bone ◽

Control Area ◽

Cranial Bone ◽

Long Term Results ◽

Tissue Samples ◽

Defect Sites

Abstract Bone defects that cannot be healed completely are termed critical-sized defects and can be used to test bone grafts for medicine, dentistry, and periodontology. The aim of the present study was to detect the effects of a xenograft (Unilab Surgibone) on bone building in experimentally created parietal bone defects in rats. Standardized parietal bone defects were created in 16 rats, and each defect had a circular morphology 6 mm in diameter. The right defect sites were filled with porous particle material, and the left site was used as control. After the 3rd, 6th, and 12th months, rats were killed and tissue samples obtained from the related site of the cranium. Subsequently, histological sections were taken and stained with different stains for evaluation under light microscope. The rate of bone formation was assessed using a semiquantitative method. These results showed that dense collagenous tissue was observed in the control area during the third month, whereas xenograft particles were surrounded by a fibrous tissue layer at the implantation site. Osteoclast-like cells were also observed. There was also no significant bone repair at other observation periods. It can be concluded that the material used had no evidence of resorption and does not enhance bone formation. However, it seems biocompatible, osteoconductive, and could be used in a limited manner as a material for filling osseous defects in clinical practice.

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Direct contribution of skeletal muscle mesenchymal progenitors to bone repair

10.1101/2020.09.08.287367 ◽

2020 ◽

Author(s):

Julien Anais ◽

Kanagalingam Anuya ◽

Megret Jérome ◽

Luka Marine ◽

Ménager Mickaël ◽

...

Keyword(s):

Skeletal Muscle ◽

Bone Formation ◽

Bone Regeneration ◽

Bone Repair ◽

Fibrous Tissue ◽

Fibrotic Response ◽

Fracture Callus ◽

Mesenchymal Progenitors ◽

Direct Contribution ◽

Bone Injury

AbstractTissue regeneration relies on the activation of tissue resident stem cells concomitant with a transient fibrous tissue deposition to allow functional tissue recovery. Bone regeneration involves skeletal stem/progenitors from periosteum and bone marrow, the formation of a fibrous callus followed by the deposition of cartilage and bone to consolidate the fracture. Here, we show that mesenchymal progenitors residing in skeletal muscle adjacent to the bone fracture play a crucial role in mediating the initial fibrotic response to bone injury and also participate in cartilage and bone formation in the fracture callus. Combined lineage and scRNAseq analyses reveal that skeletal muscle mesenchymal progenitors adopt a fibrogenic fate before they engage in a chondrogenic fate after fracture. In polytrauma, where bone and skeletal muscle are injured, skeletal muscle mesenchymal progenitors fail to undergo fibrogenesis and chondrogenesis. This leads to impaired healing and persistent callus fibrosis originating from skeletal muscle. Thus, essential bone-muscle interactions govern bone regeneration through the direct contribution of skeletal muscle as a source of mesenchymal progenitors driving the fibrotic response and fibrotic remodeling, and supporting cartilage and bone formation.

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3D-Printed Ceramic Bone Scaffolds with Variable Pore Architectures

International Journal of Molecular Sciences ◽

10.3390/ijms21186942 ◽

2020 ◽

Vol 21 (18) ◽

pp. 6942

Author(s):

Ho-Kyung Lim ◽

Seok-Jin Hong ◽

Sun-Ju Byeon ◽

Sung-Min Chung ◽

Sung-Woon On ◽

...

Keyword(s):

Bone Formation ◽

Bone Regeneration ◽

Pore Size ◽

Block Type ◽

Regeneration Ability ◽

Bone Scaffold ◽

Digital Light Processing ◽

Pore Sizes ◽

Initial Stage ◽

3D Printed

This study evaluated the mechanical properties and bone regeneration ability of 3D-printed pure hydroxyapatite (HA)/tricalcium phosphate (TCP) pure ceramic scaffolds with variable pore architectures. A digital light processing (DLP) 3D printer was used to construct block-type scaffolds containing only HA and TCP after the polymer binder was completely removed by heat treatment. The compressive strength and porosity of the blocks with various structures were measured; scaffolds with different pore sizes were implanted in rabbit calvarial models. The animals were observed for eight weeks, and six animals were euthanized in the fourth and eighth weeks. Then, the specimens were evaluated using radiological and histological analyses. Larger scaffold pore sizes resulted in enhanced bone formation after four weeks (p < 0.05). However, in the eighth week, a correlation between pore size and bone formation was not observed (p > 0.05). The findings showed that various pore architectures of HA/TCP scaffolds can be achieved using DLP 3D printing, which can be a valuable tool for optimizing bone-scaffold properties for specific clinical treatments. As the pore size only influenced bone regeneration in the initial stage, further studies are required for pore-size optimization to balance the initial bone regeneration and mechanical strength of the scaffold.

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The Potential of Antibiotic Collagen Based Biocomposites for the Treatment of Bone Defects

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.587.404 ◽

2013 ◽

Vol 587 ◽

pp. 404-411

Author(s):

Ioan Cristescu ◽

Lucian Marina ◽

Daniel Vilcioiu ◽

F. Safta ◽

M. Istodorescu ◽

...

Keyword(s):

Bone Formation ◽

Bone Growth ◽

Local Treatment ◽

Bone Destruction ◽

Bone Defects ◽

New Bone Formation ◽

Collagen Scaffolds ◽

Local Tissue ◽

Local Bone ◽

Antibiotic Delivery

Antibiotic delivery systems used in the past have consisted primarily of impregnated cement beads that required routine removal once the antibiotic had eluded completely. With the development of collagen scaffolds that could be used to fill bony defects the antibiotic cold be delivered from the scaffold used to sustain local bone growth. Over the course of two years antibiotic loaded collagen scaffolds were used in the local treatment of 21patients suffering of complicated fractures including bone defects, infections or pseudoarthrosis, all of them of traumatic nature. At the time of the initial surgical debridement or at subsequent second look procedures once local tissue viability was observed the antibiotic loaded collagen scaffold was inserted in the tissue defect and never removed. Excellent results were obtained and the infection was brought under control by use of both surgical and antibiotic modalities. Bone grafting was used in 6 cases where the defects were extensive. Where there was less extensive bone destruction the scaffold was a good adjuvant in new bone formation. Use of antibiotic loaded collagen scaffolds is a reliable and effective means of local antibiotic delivery system combining both the new bone formation capacity of the scaffold to hold osteoblasts with the ability to deliver high doses of antibiotic in the local tissue environment and thus avoiding the systemic toxicity.

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3D Culture of Bone Marrow-Derived Mesenchymal Stem Cells (BMSCs) Could Improve Bone Regeneration in 3D-Printed Porous Ti6Al4V Scaffolds

Stem Cells International ◽

10.1155/2018/2074021 ◽

2018 ◽

Vol 2018 ◽

pp. 1-13 ◽

Cited By ~ 12

Author(s):

Lingjia Yu ◽

Yuanhao Wu ◽

Jieying Liu ◽

Bo Li ◽

Bupeng Ma ◽

...

Keyword(s):

Stem Cells ◽

Bone Marrow ◽

Mesenchymal Stem Cells ◽

Bone Formation ◽

3D Culture ◽

Bone Defects ◽

New Bone Formation ◽

Mandibular Bone ◽

3D Printed ◽

Bone Defect Reconstruction

Mandibular bone defect reconstruction is an urgent challenge due to the requirements for daily eating and facial aesthetics. Three-dimensional- (3D-) printed titanium (Ti) scaffolds could provide patient-specific implants for bone defects. Appropriate load-bearing properties are also required during bone reconstruction, which makes them potential candidates for mandibular bone defect reconstruction implants. However, in clinical practice, the insufficient osteogenesis of the scaffolds needs to be further improved. In this study, we first encapsulated bone marrow-derived mesenchymal stem cells (BMSCs) into Matrigel. Subsequently, the BMSC-containing Matrigels were infiltrated into porous Ti6Al4V scaffolds. The Matrigels in the scaffolds provided a 3D culture environment for the BMSCs, which was important for osteoblast differentiation and new bone formation. Our results showed that rats with a full thickness of critical mandibular defects treated with Matrigel-infiltrated Ti6Al4V scaffolds exhibited better new bone formation than rats with local BMSC injection or Matrigel-treated defects. Our data suggest that Matrigel is able to create a more favorable 3D microenvironment for BMSCs, and Matrigel containing infiltrated BMSCs may be a promising method for enhancing the bone formation properties of 3D-printed Ti6Al4V scaffolds. We suggest that this approach provides an opportunity to further improve the efficiency of stem cell therapy for the treatment of mandibular bone defects.

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