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Preparation of laponite bioceramics for potential bone tissue engineering applications.

Wang C, Wang S, Li K, Ju Y, Li J, Zhang Y, Li J, Liu X, Shi X, Zhao Q - PLoS ONE (2014)

Bottom Line: Our results reveal that the LAP bioceramic possesses an excellent surface hydrophilicity and serum absorption capacity, and good cytocompatibility and hemocompatibility as demonstrated by resazurin reduction assay of rat mesenchymal stem cells (rMSCs) and hemolytic assay of pig red blood cells, respectively.Most strikingly, alkaline phosphatase activity together with alizarin red staining results reveal that the produced LAP bioceramic is able to induce osteoblast differentiation of rMSCs in growth medium without any inducing factors.Finally, in vivo animal implantation, acute systemic toxicity test and hematoxylin and eosin (H&E)-staining data demonstrate that the prepared LAP bioceramic displays an excellent biosafety and is able to heal the bone defect.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedics, Shanghai First People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, P. R. China.

ABSTRACT
We report a facile approach to preparing laponite (LAP) bioceramics via sintering LAP powder compacts for bone tissue engineering applications. The sintering behavior and mechanical properties of LAP compacts under different temperatures, heating rates, and soaking times were investigated. We show that LAP bioceramic with a smooth and porous surface can be formed at 800°C with a heating rate of 5°C/h for 6 h under air. The formed LAP bioceramic was systematically characterized via different methods. Our results reveal that the LAP bioceramic possesses an excellent surface hydrophilicity and serum absorption capacity, and good cytocompatibility and hemocompatibility as demonstrated by resazurin reduction assay of rat mesenchymal stem cells (rMSCs) and hemolytic assay of pig red blood cells, respectively. The potential bone tissue engineering applicability of LAP bioceramic was explored by studying the surface mineralization behavior via soaking in simulated body fluid (SBF), as well as the surface cellular response of rMSCs. Our results suggest that LAP bioceramic is able to induce hydroxyapatite deposition on its surface when soaked in SBF and rMSCs can proliferate well on the LAP bioceramic surface. Most strikingly, alkaline phosphatase activity together with alizarin red staining results reveal that the produced LAP bioceramic is able to induce osteoblast differentiation of rMSCs in growth medium without any inducing factors. Finally, in vivo animal implantation, acute systemic toxicity test and hematoxylin and eosin (H&E)-staining data demonstrate that the prepared LAP bioceramic displays an excellent biosafety and is able to heal the bone defect. Findings from this study suggest that the developed LAP bioceramic holds a great promise for treating bone defects in bone tissue engineering.

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The SEM surface morphologies of the LAP compact.The LAP compact (a) before and (b–e) after sintered. (b) Sample #2, (c) Sample #3, (d) Sample #5, and (e) Sample #4. See Table 1 for sample information.
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pone-0099585-g001: The SEM surface morphologies of the LAP compact.The LAP compact (a) before and (b–e) after sintered. (b) Sample #2, (c) Sample #3, (d) Sample #5, and (e) Sample #4. See Table 1 for sample information.

Mentions: Figure 1 shows the morphology of LAP compacts and bioceramics under different sintering conditions. Although the LAP compact shows a regular smooth surface, the poor water stability limits its applications. The sintering process does not seem to alter the relatively smooth surface when compared to the LAP compact before sintering (Figures 1b, 1d, and 1e), except the case shown in Figure 1c, where cracks are observed on the surface of LAP bioceramic. It appears that in this case, while the sintering temperature is sufficient to convert the LAP compact to ceramic prototype, however, the sintering time is too short to lead to a smooth surfaced biocermaic. It is notable that some regular small holes can be detected in Figure 1d. With such a rough surface, the attachment and proliferation of stem cells may be facilitated. We then compared the mechanical property of the LAP bioceramic via an instrumented nanoindentation test (Figure 2). The hardness-displacement (Figure 2a) and modulus-displacement (Figure 2b) curves of LAP compact and LAP bioceramics show that both hardness and modulus have an apparent dip in the depth range of less than 20 nm, then increase gradually and level off. Apparently, the final hardness and modulus increase with sintering temperature and sintering time. Figures 2c and 2d show the harmonic contact stiffness-displacement and load-displacement curves. The nearly identical relationship between maximum harmonic contact stiffness and maximum load as a function of sintering temperature and sintering time can be found. Therefore, a optimized hardness, modulus, stiffness, and load can be obtained at a sintering temperature of 800°C, sintering time of 6 h, and heating rate of 5°C/min. LAP ceramics prepared under the optimized conditions was selected for subsequent studies.


Preparation of laponite bioceramics for potential bone tissue engineering applications.

Wang C, Wang S, Li K, Ju Y, Li J, Zhang Y, Li J, Liu X, Shi X, Zhao Q - PLoS ONE (2014)

The SEM surface morphologies of the LAP compact.The LAP compact (a) before and (b–e) after sintered. (b) Sample #2, (c) Sample #3, (d) Sample #5, and (e) Sample #4. See Table 1 for sample information.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4067276&req=5

pone-0099585-g001: The SEM surface morphologies of the LAP compact.The LAP compact (a) before and (b–e) after sintered. (b) Sample #2, (c) Sample #3, (d) Sample #5, and (e) Sample #4. See Table 1 for sample information.
Mentions: Figure 1 shows the morphology of LAP compacts and bioceramics under different sintering conditions. Although the LAP compact shows a regular smooth surface, the poor water stability limits its applications. The sintering process does not seem to alter the relatively smooth surface when compared to the LAP compact before sintering (Figures 1b, 1d, and 1e), except the case shown in Figure 1c, where cracks are observed on the surface of LAP bioceramic. It appears that in this case, while the sintering temperature is sufficient to convert the LAP compact to ceramic prototype, however, the sintering time is too short to lead to a smooth surfaced biocermaic. It is notable that some regular small holes can be detected in Figure 1d. With such a rough surface, the attachment and proliferation of stem cells may be facilitated. We then compared the mechanical property of the LAP bioceramic via an instrumented nanoindentation test (Figure 2). The hardness-displacement (Figure 2a) and modulus-displacement (Figure 2b) curves of LAP compact and LAP bioceramics show that both hardness and modulus have an apparent dip in the depth range of less than 20 nm, then increase gradually and level off. Apparently, the final hardness and modulus increase with sintering temperature and sintering time. Figures 2c and 2d show the harmonic contact stiffness-displacement and load-displacement curves. The nearly identical relationship between maximum harmonic contact stiffness and maximum load as a function of sintering temperature and sintering time can be found. Therefore, a optimized hardness, modulus, stiffness, and load can be obtained at a sintering temperature of 800°C, sintering time of 6 h, and heating rate of 5°C/min. LAP ceramics prepared under the optimized conditions was selected for subsequent studies.

Bottom Line: Our results reveal that the LAP bioceramic possesses an excellent surface hydrophilicity and serum absorption capacity, and good cytocompatibility and hemocompatibility as demonstrated by resazurin reduction assay of rat mesenchymal stem cells (rMSCs) and hemolytic assay of pig red blood cells, respectively.Most strikingly, alkaline phosphatase activity together with alizarin red staining results reveal that the produced LAP bioceramic is able to induce osteoblast differentiation of rMSCs in growth medium without any inducing factors.Finally, in vivo animal implantation, acute systemic toxicity test and hematoxylin and eosin (H&E)-staining data demonstrate that the prepared LAP bioceramic displays an excellent biosafety and is able to heal the bone defect.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedics, Shanghai First People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, P. R. China.

ABSTRACT
We report a facile approach to preparing laponite (LAP) bioceramics via sintering LAP powder compacts for bone tissue engineering applications. The sintering behavior and mechanical properties of LAP compacts under different temperatures, heating rates, and soaking times were investigated. We show that LAP bioceramic with a smooth and porous surface can be formed at 800°C with a heating rate of 5°C/h for 6 h under air. The formed LAP bioceramic was systematically characterized via different methods. Our results reveal that the LAP bioceramic possesses an excellent surface hydrophilicity and serum absorption capacity, and good cytocompatibility and hemocompatibility as demonstrated by resazurin reduction assay of rat mesenchymal stem cells (rMSCs) and hemolytic assay of pig red blood cells, respectively. The potential bone tissue engineering applicability of LAP bioceramic was explored by studying the surface mineralization behavior via soaking in simulated body fluid (SBF), as well as the surface cellular response of rMSCs. Our results suggest that LAP bioceramic is able to induce hydroxyapatite deposition on its surface when soaked in SBF and rMSCs can proliferate well on the LAP bioceramic surface. Most strikingly, alkaline phosphatase activity together with alizarin red staining results reveal that the produced LAP bioceramic is able to induce osteoblast differentiation of rMSCs in growth medium without any inducing factors. Finally, in vivo animal implantation, acute systemic toxicity test and hematoxylin and eosin (H&E)-staining data demonstrate that the prepared LAP bioceramic displays an excellent biosafety and is able to heal the bone defect. Findings from this study suggest that the developed LAP bioceramic holds a great promise for treating bone defects in bone tissue engineering.

Show MeSH
Related in: MedlinePlus