In vivo investigation of PCL/PHBV/Hydroxyapatite Nanocomposite Scaffold in Regeneration of Critical-sized Bone Defects

Author(s):  
Amir Nahanmoghadam ◽  
Maryam Asemani ◽  
Vahabodin Goodarzi ◽  
Somayeh Ebrahimi-Barough
2019 ◽  
Vol 70 (6) ◽  
pp. 1983-1987
Author(s):  
Cristian Trambitas ◽  
Anca Maria Pop ◽  
Alina Dia Trambitas Miron ◽  
Dorin Constantin Dorobantu ◽  
Flaviu Tabaran ◽  
...  

Large bone defects are a medical concern as these are often unable to heal spontaneously, based on the host bone repair mechanisms. In their treatment, bone tissue engineering techniques represent a promising approach by providing a guide for osseous regeneration. As bioactive glasses proved to have osteoconductive and osteoinductive properties, the aim of our study was to evaluate by histologic examination, the differences in the healing of critical-sized calvarial bone defects filled with bioactive glass combined with adipose-derived mesenchymal stem cells, compared to negative controls. We used 16 male Wistar rats subjected to a specific protocol based on which 2 calvarial bone defects were created in each animal, one was filled with Bon Alive S53P4 bioactive glass and adipose-derived stem cells and the other one was considered control. At intervals of one week during the following month, the animals were euthanized and the specimens from bone defects were histologically examined and compared. The results showed that this biomaterial was biocompatible and the first signs of osseous healing appeared in the third week. Bone Alive S53P4 bioactive glass could be an excellent bone substitute, reducing the need of bone grafts.


Author(s):  
Minh Khai Le Thieu ◽  
Håvard Jostein Haugen ◽  
Javier Sanz‐Esporrin ◽  
Mariano Sanz ◽  
Ståle Petter Lyngstadaas ◽  
...  

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Philipp S. Lienemann ◽  
Stéphanie Metzger ◽  
Anna-Sofia Kiveliö ◽  
Alain Blanc ◽  
Panagiota Papageorgiou ◽  
...  

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.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Hai Wang ◽  
Xiao Chang ◽  
Guixing Qiu ◽  
Fuzhai Cui ◽  
Xisheng Weng ◽  
...  

It still remains a major challenge to repair large bone defects in the orthopaedic surgery. In previous studies, a nanohydroxyapatite/collagen/poly(L-lactic acid) (nHAC/PLA) composite, similar to natural bone in both composition and structure, has been prepared. It could repair small sized bone defects, but they were restricted to repair a large defect due to the lack of oxygen and nutrition supply for cell survival without vascularization. The aim of the present study was to investigate whether nHAC/PLA composites could be vascularized in vivo. Composites were implanted intramuscularly in the groins of rabbits for 2, 6, or 10 weeks (n=5×3). After removing, the macroscopic results showed that there were lots of rich blood supply tissues embracing the composites, and the volumes of tissue were increasing as time goes on. In microscopic views, blood vessels and vascular sprouts could be observed, and microvessel density (MVD) of the composites trended to increase over time. It suggested that nHAC/PLA composites could be well vascularized by implanting in vivo. In the future, it would be possible to generate vascular pedicle bone substitutes with nHAC/PLA composites for grafting.


2021 ◽  
Author(s):  
Wei Hu ◽  
Jiawu Liang ◽  
Song Liao ◽  
Zhidong Zhao ◽  
Yuxing Wang ◽  
...  

Abstract Background Ionizing radiation poses a challenge to the healing of bone defects. Radiation therapy and accidental exposure to gamma-ray (γ-ray) radiation inhibit bone formation and increase the risk of fractures. Cortical bone-derived stem cells (CBSCs) are essential for osteogenic lineages, bone maintenance, and repair. This study aimed to investigate the effects of melatonin on postradiation CBSCs and bone defects. Methods CBSCs were extracted from C57/BL6 mice and were identified by flow cytometry. The effects of exogenous melatonin on the self-renewal and osteogenic capacity of postradiation CBSCs were detected in vitro. The underlying mechanisms in terms of genomic stability, apoptosis and oxidative stress-related signaling were further analyzed by western blotting, flow cytometry and immunofluorescence. Finally, the effects of melatonin on healing in postradiation bone defects were evaluated in vivo by micro-CT and immunohistochemical analysis. Results The radiation-induced reduced self-renewal and osteogenic capacity were partially reversed in postradiation CBSCs treated with melatonin. Melatonin maintained the genomic stability and apoptosis of postradiation CBSCs, and intracellular oxidative stress was decreased significantly while antioxidant-related enzymes were enhanced. Western blotting verified the anti-inflammatory effect of melatonin by downregulating the levels of IL-6 and TNF-α via extracellular regulated kinase (ERK)/nuclear factor erythroid 2-related factor 2 (NRF2)/heme oxygenase 1 (HO-1) signaling, distinct from its antioxidant effect via NRF2 signaling. In vivo experiments demonstrated that the newly formed bone in the melatonin plus Matrigel group had higher trabecular bone volume per tissue volume (BV/TV) and bone mineral density (BMD) values, and lower levels of IL-6 and TNF-α than those in the irradiation and the Matrigel groups. Conclusions This study suggested the potential of melatonin to protect CBSCs against γ-ray radiation and to assist the healing of postradiation bone defects.


2011 ◽  
Vol 5 (1) ◽  
pp. 63-71 ◽  
Author(s):  
Oliver D Schneider ◽  
Dirk Mohn ◽  
Roland Fuhrer ◽  
Karina Klein ◽  
Käthi Kämpf ◽  
...  

Background: The purpose of this preliminary study was to assess the in vivo performance of synthetic, cotton wool-like nanocomposites consisting of a biodegradable poly(lactide-co-glycolide) fibrous matrix and containing either calcium phosphate nanoparticles (PLGA/CaP 60:40) or silver doped CaP nanoparticles (PLGA/Ag-CaP 60:40). Besides its extraordinary in vitro bioactivity the latter biomaterial (0.4 wt% total silver concentration) provides additional antimicrobial properties for treating bone defects exposed to microorganisms. Materials and Methods: Both flexible artificial bone substitutes were implanted into totally 16 epiphyseal and metaphyseal drill hole defects of long bone in sheep and followed for 8 weeks. Histological and histomorphological analyses were conducted to evaluate the biocompatibility and bone formation applying a score system. The influence of silver on the in vivo performance was further investigated. Results: Semi-quantitative evaluation of histology sections showed for both implant materials an excellent biocompatibility and bone healing with no resorption in the adjacent bone. No signs of inflammation were detectable, either macroscopically or microscopically, as was evident in 5 µm plastic sections by the minimal amount of inflammatory cells. The fibrous biomaterials enabled bone formation directly in the centre of the former defect. The area fraction of new bone formation as determined histomorphometrically after 8 weeks implantation was very similar with 20.5 ± 11.2 % and 22.5 ± 9.2 % for PLGA/CaP and PLGA/Ag-CaP, respectively. Conclusions: The cotton wool-like bone substitute material is easily applicable, biocompatible and might be beneficial in minimal invasive surgery for treating bone defects.


2014 ◽  
Vol 26 (01) ◽  
pp. 1450005 ◽  
Author(s):  
Tingwei Bao ◽  
Huiming Wang ◽  
Wentao Zhang ◽  
Xuefeng Xia ◽  
Jiabei Zhou ◽  
...  

Purpose: Plasmid loading into scaffolds to enhance sustained release of growth factors is an important focus of regenerative medicine. The aim of this study was to build gene-activated matrices (GAMs) and examine the bone augmentation properties. Methods: Generation 5 polyamidoamine dendrimers (G5 dPAMAM)/plasmid recombinant human bone morphogenetic protein-2 (rhBMP-2) complexes were immobilized into beta-tricalcium phosphate (β-TCP)/type I collagen porous scaffolds. After cultured with rat mesenchymal stem cells (rMSCs), transfection efficiencies were examined. The secretion of rhBMP-2 and alkaline phosphatase (ALP) were detected to evaluate the osteogenic properties. Scanning electron microscopy (SEM) was used to observe attachment and proliferation. Moreover, we applied these GAMs directly into freshly created segmental bone defects in rat femurs, and their osteogenic efficiencies were evaluated. Results: Released plasmid complexes were transfected into stem cells and were expressed, which caused osteogenic differentiations of rat mesenchymal stem cells (rMSCs). SEM analysis showed excellent cell attachment. Bioactivity of plasmid rhBMP-2 was maintained in vivo, and the X-ray observation, histological analysis and immunohistochemistry (IHC) of bone tissue demonstrated that the bone healing in segmental femoral defects was enhanced by implantation of GAMs. Conclusions: Such biomaterials offer therapeutic opportunities in critical-sized bone defects.


2017 ◽  
Vol 16 (1) ◽  
Author(s):  
Che Nor Zarida Che Seman ◽  
Zamzuri Zakaria ◽  
Zunariah Buyong ◽  
Mohd Shukrimi Awang ◽  
Ahmad Razali Md Ralib @ Md Raghib

Introduction: A novel injectable calcium phosphate bone cement (osteopaste) has been developed. Its potential application in orthopaedics as a filler of bone defects has been studied. The biomaterial was composed of tetra-calcium phosphate (TTCP) and tricalcium phosphate (TCP) powder. The aim of the present study was to evaluate the healing process of osteopaste in rabbit tibia. Materials and method: The implantation procedure was carried out on thirty-nine of New Zealand white rabbits. The in vivo bone formation was investigated by either implanting the Osteopaste, Jectos or MIIG – X3 into a critical size defect (CSD) model in the proximal tibial metaphysis. CSD without treatment served as negative control. After 1 day, 6 and 12 weeks, the rabbits were euthanized, the bone were harvested and subjected for analysis. Results: Radiological images and histological sections revealed integration of implants with bone tissue with no signs of graft rejection. There was direct contact between osteopaste material and host bone. The new bone was seen bridging the defect. Conclusion: The result showed that Osteopaste could be a new promising biomaterial for bone repair and has a potential in bone tissue engineering.


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