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ABSTRACT: Regenerative medicine treatments that combine the use of cells and materials may open new options for tissue/organ repair and regeneration. The microenvironment of mesenchymal stem cells (MSCs) strictly regulates their self-renewal and functions. In this study, when rat bone marrow derived MSCs (rBMSCs) and rat adipose tissue derived MSCs (rAMSCs) in passages 2-4 were cultured on different substrates, they presented the cellular functions to be dependent of substrate stiffness. The cells attached better on the softer substrate than on the stiffer one. The substrate stiffness had no significant influence on the proliferation of those cells. However, the substrate stiffness significantly promoted the osteogenic differentiation of the two kinds of stem cells. Furthermore, rBMSCs cultured on the same stiffness expressed more osteoblast-related markers than rAMSCs. In addition, combined biomaterials and biochemical reagents treatment yielded a stronger effect on osteogenic differentiation of MSCs than either treatment alone. These results have significant implications for further extending our capabilities in engineering functional tissue substitutes.
Journal of Biomedical Materials Research Part A 04/2013; · 2.63 Impact Factor
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ABSTRACT: A combined sulfated silk fibroin scaffold is fabricated by modifying a knitted silk scaffold with sulfated silk fibroin sponges. In vitro hemocompatibility evaluation reveals that the combined sulfated silk fibroin scaffolds reduce platelet adhesion and activation, and prolong the activated partial thromboplastin time (APTT), thrombin time (TT), and prothrombin time (PT). The response of porcine endothelial cells (ECs) and smooth muscle cells (SMCs) on the scaffolds is studied to evaluate the cytocompatibility of the scaffolds. Vascular cells are seeded on the scaffolds and cultured for 2 weeks. The scaffolds demonstrate enhanced EC adhesion, proliferation, and maintenance of cellular functions. Moreover, the scaffolds inhibit SMC proliferation and induce expression of contractile SMC marker genes.
Macromolecular Bioscience 04/2013; · 3.89 Impact Factor
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ABSTRACT: It has been demonstrated that nanostructured materials, compared with conventional materials, may promote greater amounts of specific protein interactions, thereby more efficiently stimulating new bone formation. It has also been indicated that, when features or ingredients of scaffolds are nanoscaled, a variety of interactions can be stimulated at the cellular level. Some of those interactions induce favorable cellular functions while others may leads to toxicity. This review presents the mechanism of interactions between nanoscaled materials and cells and focuses on the current research status of nanostructured scaffolds for bone tissue engineering. Firstly, the main requirements for bone tissue engineering scaffolds were discussed. Then, the mechanism by which nanoscaled materials promote new bone formation was explained, following which the current research status of main types of nanostructured scaffolds for bone tissue engineering was reviewed and discussed. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Journal of Biomedical Materials Research Part A 02/2013; · 2.63 Impact Factor
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ABSTRACT: Carbon nanotubes (CNTs), one of the most concerned nanomaterials, with unique electrical, mechanical and surface properties, have been shown suitable for biomedical application. In this study, we evaluated attachment, proliferation, osteogenic gene expression, ALP/DNA, protein/DNA and mineralization of human adipose-derived stem cells cultured in vitro on multi-walled carbon nanotubes (MWNTs) and graphite (GP) compacts with the same dimension. Moreover, we assessed the effect of these two kinds of compacts on ectopic bone formation in vivo. First of all, higher ability of the MWNTs compacts to adsorb proteins, comparing with the GP compacts, was shown. During the conventional culture, it was shown that MWNTs could induce the expression of ALP, cbfa1 and COLIA1 genes while GP could not. Furthermore, alkaline phosphatase (ALP)/DNA and protein/DNA of the cell on the MWNTs compacts, was significantly higher than those of the cells on the GP compacts. With the adsorption of the proteins in culture medium with 50% fetal bovine serum (FBS) in advance, the increments of the ALP/DNA and protein/DNA for the MWNTs compacts were found respectively significantly more than the increments of those for the GP compacts, suggesting that the larger amount of protein adsorbed on the MWNTs was crucial. More results showed that ALP/DNA and protein/DNA of the cells on the two kinds of compacts pre-soaked in culture medium having additional rhBMP-2 were both higher than those of the cells on the samples re-soaked in culture medium with 50% FBS, and that those values for the MWNTs compacts increased much more. Larger mineral content was found on the MWNTs compacts than on the GP compacts at day 7. In vivo experiment showed that the MWNTs could induce ectopic bone formation in the dorsal musculature of ddy mice while GP could not. The results indicated that MWNTs might stimulate inducible cells in soft tissues to form inductive bone by concentrating more proteins, including bone-inducing proteins.
Biomaterials 04/2012; 33(19):4818-27. · 7.40 Impact Factor
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ABSTRACT: Endothelialization of vascular grafts prior to implantation has been investigated widely to enhance biocompatibility and antithrombogenicity. Thrombosis of artificial vessels is typically caused by platelet adhesion and agglomeration following endothelial cells detachment when exposed to the shear stress of blood circulation. The present study thus aimed at preventing platelet adhesion and aggregation onto biomaterials before the endothelial confluence is fully achieved. We report this modification of poly(lactic-co-glycolic acid) (PLGA) scaffolds, both to impart hemocompatibility to prevent platelet adhesion and aggregation before the endothelial confluence is fully achieved and to support EC growth to accelerate endothelialization. The modification was achieved by covalent immobilization of sulfated silk fibroin on PLGA scaffolds using γ irradiation. Using phosphate-buffered saline (PBS) as an aging medium, it was demonstrated that the scaffolds prepared by γ irradiation had a good retention of sulfated silk fibroin. The systematic in vitro hemocompatibility evaluation revealed that sulfated silk fibroin covalently immobilized PLGA (S-PLGA) scaffolds-reduced platelet adhesion and activation, prolonged whole blood clotting time, activated partial thromboplastin time (APTT), thrombin time (TT), and prothrombin time (PT). To evaluate further in vitro cytocompatibility of the scaffolds, we seeded vascular ECs on the scaffolds and cultured them for 2 weeks. The ECs were seen to attach and proliferate well on S-PLGA scaffolds, forming cell aggregates that gradually increased in size and fused with adjacent cell aggregates to form a monolayer covering the scaffold surface. Moreover, it was demonstrated through the gene transcript levels and the protein expressions of EC-specific markers that the cell functions of ECs on S-PLGA scaffolds were better preserved than those on PLGA scaffolds. Therefore, this study has described the generation of a vascular graft that possesses the unique ability to display excellent hemocompatibility while simultaneously supporting extensive endothelialization.
Biomacromolecules 06/2011; 12(8):2914-24. · 5.48 Impact Factor
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ABSTRACT: Bone repair ability of microencapsulated chitosan, nanohydroxyapatite/collagen (nHAC), and poly(L-lactide) (PLLA)-based microsphere-scaffold delivery system was investigated in present research, with nHAC/PLLA composite scaffold as a control. Chitosan microspheres (CMs) encapsulated with bone morphogenetic protein-2-derived synthetic peptide were incorporated into nHAC and PLLA-based matrix via a thermally induced phase separation method, in which dioxane was used as the solvent for PLLA. Compared with the rapid release from CMs, the synthetic peptide was delivered from CMs/nHAC/PLLA microsphere-scaffold composite in a temporally controlled manner, depending on the degradation of both incorporated CMs and PLLA matrix. MC3T3-E1 osteoblastic cells were seeded into nHAC/PLLA and CMs/nHAC/PLLA scaffolds, respectively, and in vitro cytocompatibility was tested by scanning electron microscopy and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The results indicated that, with the appearance of CMs in microsphere-scaffold composite, the osteoblasts exhibit better morphology and proliferation ability. In vivo tissue compatibility was evaluated by transplanting the scaffolds into rabbit femoral condyles with a defect 6 mm in diameter. After implanting for 4, 8, and 12 weeks, respectively, radiographic and histological observation revealed that the CMs/nHAC/PLLA composite can accelerate the regeneration of cancellous bone defect as compared with the nHAC/PLLA scaffold. The results demonstrated that the CMs/nHAC/PLLA possesses better biocompatibility, which should be attributed to both the incorporated chitosan component and the encapsulated bioactive synthetic peptide. The promising CMs/nHAC/PLLA microsphere-scaffold composite can be used as delivery system for multiple bioactive factors or as inductive implant scaffold for bone regeneration.
Artificial Organs 06/2011; 35(7):E119-28. · 2.00 Impact Factor
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ABSTRACT: One of the major downfalls of tissue-engineered small-diameter vascular grafts is the inability to obtain a confluent endothelium on the lumenal surface. Loosely attached endothelial cells (ECs) are easily separated from the vessel wall when exposed to the in vivo vascular system. Thus any denuded areas on the lumenal surface of vascular grafts may lead to thrombus formation via platelet deposition and activation. If the denuded areas could express anticoagulant activity until the endothelial cell lining is fully achieved, it may greatly improve the chances of successful vascular reconstruction. In this study, we fabricate sulfated silk fibroin nanofibrous scaffolds (S-silk scaffolds) and assess the anticoagulant activity and cytocompatibility of S-silk scaffolds in vitro in order to improve the antithrombogenicity and get some insights into its potential use for vascular tissue engineering. Sulfated silk fibroin was prepared by reaction with chlorosulphonic acid in pyridine, and then was developed to form an S-silk scaffold by electrospinning technique. FTIR analyses identified the successful incorporation of sulfate groups in silk fibroin molecules. It was found that the anticoagulant activity of S-silk scaffolds was significantly enhanced compared with silk fibroin nanofibrous scaffolds (Silk scaffolds). Vascular cells, including ECs and smooth muscle cells (SMCs), demonstrated strong attachment to S-silk scaffolds and proliferated well with higher expression of some phenotype-related marker genes and proteins. Overall, the data in this study suggest the suitability of S-silk scaffolds used along with vascular cells for the development of tissue-engineered vascular grafts.
Biomaterials 03/2011; 32(15):3784-93. · 7.40 Impact Factor
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ABSTRACT: Microstructure is indispensable for the osteoinduction of calcium phosphate ceramics. To study how microstructure takes its role and explore the mechanism of the osteoinduction, we evaluated attachment, proliferation, alkaline phosphatase (ALP)/DNA, protein/DNA, and mineralization of human adipose-derived stem cells cultured on two kinds of biphasic calcium phosphate (BCP) ceramic discs with the same chemistry and dimension, but different microporosity and surface area. BCP-A had been found osteoinductive in vivo while BCP-B was not. During the conventional culture, ALP/DNA and protein/DNA of the cell on BCP-A with larger surface area were significantly higher than those of the cells on BCP-B. With the adsorption of the proteins in culture medium with 50% fetal bovine serum (FBS) in advance, the increments of the ALP/DNA and protein/DNA for the BCP-A were found respectively significantly more than the increments of those for BCP-B, suggesting that the larger amount of protein adsorbed on the BCP-A was crucial. More results showed that ALP/DNA and protein/DNA of the cells on the two kinds of discs presoaked in culture medium having additional rhBMP-2 were found to be both higher than those of the cells on the discs resoaked in culture medium with 50% FBS, and that those values for BCP-A increased much more. Furthermore, larger mineral content was found on BCP-A than on BCP-B at day 7. The results indicated that by increasing microporosity and thus surface areas, osteoinductive calcium phosphate ceramics concentrate more proteins, including bone-inducing proteins, and thereafter stimulate inducible cells in soft tissues to form inductive bone.
Journal of Biomedical Materials Research Part B Applied Biomaterials 02/2011; 97(1):10-9. · 2.15 Impact Factor
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ABSTRACT: The combination between chitosan (CS)-based hydrophilic extracellular matrix polysaccharide and polylactide (PLA)-based hydrophobic biodegradable aliphatic polyester is a challenge in the biomaterials field. This study investigated the formation of homogeneous chitosan/poly(L-lactide) (CS/PLLA) porous composite scaffold using a novel emulsion freeze-drying technique. An oil-in-water (O/W) emulsification system was used in the presence of surfactant Tween-80, in which CS solution was used as the water phase and PLLA solution was used as the oil phase. The composite scaffolds showed well interconnected pore structures and homogenous distribution of CS and PLLA when the PLLA volume fraction was not higher than 50%. Once the PLLA content increased to 75%, SEM micrographs demonstrated that the two components present phase separation region. FT-IR analysis revealed that there are strong hydrogen bond interactions between CS and PLLA components. The porosity of the CS/PLLA composites was in the range of 85-90% and showed a slight decrease with increasing PLLA dose. The mechanical properties of the composites lay between that of the pure CS and the PLLA scaffold. The compressive strength increased from 0.17 to 0.21 MPa, while the compressive modulus increased from 2.37 to 3.38 MPa as the PLLA contents increased from 25 to 75%. In vitro cytotoxicity was evaluated by MTT assay. The results indicated that MC3T3-E1 cell viability and proliferation in the CS/PLLA scaffold were comparable to that in the CS scaffold, and much higher than that in the PLLA scaffold. The successful hydrophilic polysaccharide and hydrophobic polyester system offers a new delivery method of growth factors and a novel scaffold design for tissue engineering.
Journal of Biomaterials Science Polymer Edition 01/2011; 23(1-4):391-404. · 1.69 Impact Factor
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Xinhui Liu, Xiaoming Li,
Yubo Fan,
Guoping Zhang,
Dongmei Li,
Wei Dong,
Ziyi Sha,
Xiaoguang Yu,
Qingling Feng,
Fuzhai Cui,
Fumio Watari
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ABSTRACT: In this study, we investigated cellular biocompatibility in vitro and segmental bone defect repairing efficacy in vivo of a previously reported fibre-reinforced scaffold, nano-hydroxyapatite/collagen/poly (L-lactic acid) (PLLA)/chitin fibres (nHACP/CF). First, attachment, proliferation, and differentiation of the goat bone mesenchymal stem cells (GBMSCs) cultured on the nHACP/CF scaffolds were evaluated in vitro. The results showed that cells attached to the scaffolds well, and there was no significant difference in cell proliferation between cells on the scaffolds and cells on the polystyrene culture plates that were used as a control. The results also showed that alkaline phosphatase (ALP)/DNA of the cells cultured on the scaffolds was significantly higher than that on the control. The in vivo study compared the bone defect repairing efficacy of nHACP/CF scaffolds with that of autograft bone. Thirty-two adult male goats with 25-mm defects in their tibias at the same anatomic site were divided into four groups. The first group was implanted with the nHACP/CF with GBMSCs. The second group was implanted with autograft bone. The third group was implanted with the nHACP/CF. Nothing was implanted in the fourth group. Bone growth was evaluated by radiography, histology, and biomechanics. The results showed that although the nHACP/CF had new bone formation, it could not repair the defect fully while nHACP/CF with GBMSCs cultured and autograft bone could repair the segmental bone defect by 8 weeks after surgery, suggesting that nHACP/CF is an appropriate scaffold for bone tissue engineering.
Journal of Biomedical Materials Research Part B Applied Biomaterials 03/2010; 94(1):44-52. · 2.15 Impact Factor
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ABSTRACT: The nano-dimensionality of nature has logically given rise to the interest in using nanomaterials in the biomedical field. Currently, a lot of investigations into carbon nanotubes (CNTs), as one of the typical nanomaterials, are being made for biomedical application. In this review, five parts, such as cellular functions induced by CNTs, apatite formation on CNTs, CNT-based tissue engineering scaffold, functionalized CNTs for the delivery of genes and drugs and CNT-based biosensors, are stated, which might indicate that CNTs, with a range of unique properties, appear suited as a biomaterial and may become a useful tool for tissue engineering. However, everything has two parts and CNTs is not an exception. There are still concerns about cytotoxicity and biodegradation of CNTs. Chemical fictionalization may be one of the effective ways to improve the 'disadvantages' and utilize the 'advantages' of CNTs. One of their 'disadvantages', unbiodegradable property, may be utilized by creating monitors in in vivo-engineered tissues or nanosized CNT-based biosensors. Other promising research points, for example proteins adsorbed on CNTs, use of CNTs in combination with other biomaterials to achieve the goals of tissue engineering, mineralization of CNTs and standard toxicological tests for CNTs, are also described in the conclusion and perspectives part.
Biomedical Materials 03/2010; 5(2):22001. · 2.16 Impact Factor
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ABSTRACT: In this study, the previously reported porous three-dimensional poly(L-lactic acid) (PLLA) scaffolds reinforced by the chitin fibers (PLLA/CF) with and without the link were evaluated in vitro. Firstly, pH value of the phosphate buffered saline lixiviums of the PLLA/CF with different content of the chitin fibers was measured to get an appropriate content of the chitin fibers in the PLLA/CF. Then, the cell functions (attachment, proliferation, alkaline phosphatase per unit cell, total protein per unit cell, and osteonectin, osteopontin, and osteocalcin gene expression) of human osteoblast-like cells (SaOS2) cultured on the PLLA/CF with the link, PLLA/CF without the link and PLLA scaffold were compared. The results showed that the link treatment did not significantly influence the pH value of the lixiviums of the scaffolds, 30% volume content might be an appropriate content of the chitin fibers in PLLA/CF scaffold to keep the pH value of the lixiviums of the scaffolds between 7.0 and 7.2 during the lixiviation time of 16 weeks, the PLLA/CF scaffold was significantly better for the attachment, proliferation, differentiation, and mineralization of the osteoblast than PLLA, the link treatment did not significantly influence these cells activities, which further suggested that PLLA/CF with the link treatment might be an appropriate scaffold for tissue engineering.
Journal of Biomedical Materials Research Part B Applied Biomaterials 02/2009; 90(2):503-9. · 2.15 Impact Factor
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ABSTRACT: Osteogenic maturation of the osteoblast is crucial for bone formation. In this study, multi-walled carbon nanotubes (MWCNTs) and graphite (GP) were pressed as compacts. The greater ability of carbon nanotubes to adsorb proteins, compared with graphite, was shown. Human osteoblast-like SaoS2 cells were cultured and the cell response to the two kinds of compacts was compared in vitro. Meanwhile, we used cell culture on the culture plate as a control. Assays for osteonectin, osteopontin and osteocalcin gene expression, total protein (TP) amount, alkaline phosphatase activity (ALP) and DNA of cells cultured on the samples were done. During the conventional culture, significantly higher osteonectin, osteopontin and osteocalcin gene expression level, ALP/DNA and TP/DNA on carbon nanotubes were found. To confirm the hypothesis that the larger amount of specific proteins adsorbed on the carbon nanotubes was crucial for this, the compacts were pre-soaked in culture medium having additional recombinant human bone morphogenetic protein-2 (rhBMP-2) before cell culture. Compared with GP, osteonectin, osteopontin and osteocalcin gene expression level, ALP/DNA and TP/DNA of the cells tested increased more on the MWCNTs after the compacts were pre-soaked in the culture medium with rhBMP-2. The results indicated that the carbon nanotubes might induce osteogenic maturation of the osteoblast by adsorbing more specific proteins.
Biomedical Materials 12/2008; 4(1):015005. · 2.16 Impact Factor
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ABSTRACT: Carbon nanotubes (CNTs) have been shown to affect cell behavior. But how and why the CNTs affect potential differentiation of the attached cells has not been largely known. In this study, multiwalled carbon nanotubes (MWNTs) and graphite (GP) were pressed as compacts. Higher ability of CNTs to adsorb proteins, compared with GP, was shown. Myoblastic mouse cells (C2C12) were cultured and the cell responses to the two kinds of compacts were compared in vitro. Meanwhile, we used cell culture on the culture plate as a control. During the conventional culture, significantly better cell attachment, proliferation, and differentiation of cells on the MWNTs were found. To confirm the hypothesis that the larger amount of protein adsorbed on the CNTs was crucial for this, we made the compacts adsorb more proteins in culture medium with 50% fetal bovine serum (FBS) before cell culture. With the adsorption of the proteins in advance, the increments of the total-protein/DNA and alkaline phosphatase (ALP)/DNA for the MWNTs was respectively as about 11 times and 18 times as the increments of those for GP and the control at both day 4 and day 7. Therefore, the CNTs might induce cellular functions by adsorbing more proteins, which indicated that the CNTs might be a candidate for scaffold material for tissue engineering.
Journal of Biomedical Materials Research Part A 10/2008; 91(1):132-9. · 2.63 Impact Factor
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ABSTRACT: Microstructure is essential for inductive bone formation in calcium phosphate materials after soft tissue implantation. We hereby evaluated activities (cell attachment, proliferation, ALP/DNA and protein/DNA) of three types of cells cultured on three kinds of calcium phosphate ceramic discs to study how microstructure takes its role in inductive bone formation. Three kinds of biphasic calcium phosphate (BCP) ceramic discs with the same chemistry and the same dimension of 10.0 x 1.0 mm3 (BCP1150-P, BCP1150-D and BCP1300), either having similar micropore sizes and surface roughness but different surface area (BCP1150-P vs BCP1150-D) or having similar surface area but different micropore sizes and different roughness (BCP1150-D vs BCP1300), were prepared. Conventionally Culturing C2C12, human bone marrow stromal cells (HBMSC) and MC3T3-E1 cells on BCP discs showed that, surface roughness did not affect cell attachment, cell proliferation and ALP expression of all cell types evaluated, while surface area did affect cell functions. ALP/DNA of C2C12 on BCP1150-P, having larger surface area, was significantly higher than on BCP1300 and BCP1150-D. Furthermore, all cells cultured on all of the three kinds of BCPs pre-soaked in culture medium having additional rhBMP-2 had a higher ALP expression than the conventional cell culture. Comparing with on BCP1300 and BCP1150-D, ALP/DNA of all cells tested increased more on BCP1150-P after the discs were pre-soaked in culture medium with rhBMP-2. The results indicated that increasing surface areas, microstructured calcium phosphate materials might concentrate more proteins (including bone-inducing proteins) that differentiate inducible cells to osteogenic cells that form inductive bone.
Biomaterials 09/2008; 29(23):3306-16. · 7.40 Impact Factor
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ABSTRACT: Chitin is a kind of seemly material to match PLLA for a scaffold, which may create an appropriate environment for the regeneration of tissues. In this study, we prepared and evaluated a new nano-hydroxyapatite/collagen/PLLA (nHACP) scaffold reinforced by chitin fibers for bone-tissue engineering. The chitin fibers were crosslinked with PLLA by dicyclohexylcarbodimide (DCC). The chemical characteristics were evaluated by Fourier transformed infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The mechanical strength was measured by compressive tests. The fibers, crosslinked with PLLA, could enhance the compressive strength of the scaffold about four times. Human marrow mesenchymal stem cells (MSCs) culture showed that the reinforced nHACP scaffolds were more cytocompatible than that without reinforcement. The crosslinks hardly affected the cytocompatibility of the reinforced scaffolds. The results suggested that the reinforced scaffolds (DCC crosslinked) might be a promising candidate for bone-tissue engineering.
Journal of Biomedical Materials Research Part B Applied Biomaterials 06/2006; 77(2):219-26. · 2.15 Impact Factor
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ABSTRACT: Tissue engineering is an increasingly popular method for repairing bone defects. However, repair of bone defects over 30 mm using tissue-engineering methods is a difficult clinical problem. In this study, we used a goat shank model to evaluate the bone-regenerating efficacy of a novel nano-hydroxyapatite/collagen/PLLA (nHACP) composite reinforced by chitin fibres. Forty adult male goats with 40 mm defects in shank at the same anatomic site were divided into four groups. The first group was the control, where nothing was implanted in the defect (defect group). The other three groups were implanted with porous pure PLLA, nHACP and nHACP reinforced by chitin fibres, respectively. Bone growth in each group was evaluated by radiography, histology, bone mineral density and mechanical strength, once every 5 weeks for 15 weeks. The results indicated that nHACP implants, both with and without chitin fibres, are better for repairing the defects than pure PLLA. However, only the reinforced implants showed nearly perfect recovery in 15 weeks after operation. So, the reinforced scaffold might be a candidate for bone tissue repair.
Biomaterials 04/2006; 27(9):1917-23. · 7.40 Impact Factor
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ABSTRACT: In this study, we reinforced the porous poly-L-lactic acid (PLLA) scaffold by chitin fibers. To enhance the strength of the scaffold further, we launched the treatment linking PLLA and chitin fibers by Dicyclohexylcarbodimide (DCC). The structures of the composites with and without link treatment were characterized by Scanning Electron Microscopy (SEM) and porosity. The chemical characteristics of the chitin fibers with and without link treatment were evaluated by Fourier-transformed infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The mechanical strength was measured by compressive tests. The results suggest that after linked with PLLA successfully, the chitin fibers can reinforce the scaffold much more effectively. The linked scaffold, with the compressive strength 4 times than PLLA, also has better structure and pore size than the scaffold without link treatment. So it is a kind of very potential appropriate scaffold for tissue engineering.
Polymer Bulletin 01/2005; 54(1):47-55. · 1.53 Impact Factor
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ABSTRACT: Owing to their unique properties, carbon nanotubes (CNTs) have emerged as a promising material for biomedical applications. Especially, CNT based coatings have recently made great achievements, which have been mainly stated in this review. They can offer favorable condition to induce the cellular functions. They can possess excellent packing density without any macroscopic porosity within the film on metals. The good bonding strength between them and the metal substrates could be achieved. Addition of CNTs can reinforce the composite coatings and the CNTs-reinforced coatings are expected to be promising for high load-bearing orthopedic implants. Furthermore, based on their unique properties, CNTs can attach to the surfaces of dentin and cementum but not to the surface of enamel, suggesting that the teeth coated with CNTs should be a possible candidate for dental materials. In addition, CNTs can be coated on polymers, bioglasses, collagen, etc. to prepare bioactive, electrically conductive 3D scaffolds for tissue engineering. Besides the current achievements, CNT based coatings possess big space to further develop, such as functionalized CNT based coatings, mineralized CNT coatings, etc., which suggesting that CNTs coatings have emerged as promising methods and potentially reward opportunities to develop the next generation of engineered materials for biomedical applications.
Surface and Coatings Technology 206(4):759-766. · 1.87 Impact Factor
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ABSTRACT: In this paper, a novel porous scaffold for bone tissue engineering was prepared with nano-hydroxyapatite/collagen/Poly-l-lactic acid (PLLA) composite reinforced by chitin fibres. To enhance the strength of the scaffold further, PLLA was linked with chitin fibres by Dicyclohexylcarbodimide (DCC). The structures of the reinforced scaffold with and without linking were characterized by Scanning Electron Microscopy (SEM). The chemical characteristics of the chitin fibres with and without linking were evaluated by Fourier-transformed infrared (FTIR) spectroscopy. The mechanical performance during degradation in vitro was investigated. The results indicated that the nano-hydroxyapatite/collagen/PLLA composite reinforced by chitin fibres with linking kept better mechanical properties than that of the composite without linking. These results denoted that the stronger interfacial bonding strength of the scaffold with linking could decrease the degradation rate in vitro. The reinforced composite with the link-treatment can be severed as a scaffold for bone tissue engineering.
Materials Science and Engineering: C.
