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Biomimetic helical rosette nanotubes and nanocrystalline hydroxyapatite coatings on titanium for improving orthopedic implants.

Zhang L, Chen Y, Rodriguez J, Fenniri H, Webster TJ - Int J Nanomedicine (2008)

Bottom Line: Some of the nanocrystalline HA formed dense coatings with HRNs on titanium.More importantly, results demonstrated enhanced osteoblast adhesion on the HRN/nanocrystalline HA-coated titanium compared with conventional uncoated titanium.Among all the HRN/nanocrystalline HA coatings tested, osteoblast adhesion was the greatest when HA nanometer particle size was the smallest.

View Article: PubMed Central - PubMed

Affiliation: Division of Engineering, Brown University, Providence, RI 02912, USA.

ABSTRACT
Natural bone consists of hard nanostructured hydroxyapatite (HA) in a nanostructured protein-based soft hydrogel template (ie, mostly collagen). For this reason, nanostructured HA has been an intriguing coating material on traditionally used titanium for improving orthopedic applications. In addition, helical rosette nanotubes (HRNs), newly developed materials which form through the self-assembly process of DNA base pair building blocks in body solutions, are soft nanotubes with a helical architecture that mimics natural collagen. Thus, the objective of this in vitro study was for the first time to combine the promising attributes of HRNs and nanocrystalline HA on titanium and assess osteoblast (bone-forming cell) functions. Different sizes of nanocrystalline HA were synthesized in this study through a wet chemical precipitation process following either hydrothermal treatment or sintering. Transmission electron microscopy images showed that HRNs aligned with nanocrystalline HA, which indicates a high affinity between both components. Some of the nanocrystalline HA formed dense coatings with HRNs on titanium. More importantly, results demonstrated enhanced osteoblast adhesion on the HRN/nanocrystalline HA-coated titanium compared with conventional uncoated titanium. Among all the HRN/nanocrystalline HA coatings tested, osteoblast adhesion was the greatest when HA nanometer particle size was the smallest. In this manner, this study demonstrated for the first time that biomimetic HRN/nanocrystalline HA coatings on titanium were cytocompatible for osteoblasts and, thus, should be further studied for improving orthopedic implants.

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Osteoblast adhesion on HA and HRN-K1-coated titanium. Data are mean ±SEM; n = 9.Notes: *p < 0.05 when compared to uncoated titanium; **p < 0.01 and ***p < 0.1 when compared with large grain size nanocrystalline HA (prepared by sintering at 700°C) with 0.001 mg/ml HRN-K1 coated on titanium.
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f6-ijn-3-323: Osteoblast adhesion on HA and HRN-K1-coated titanium. Data are mean ±SEM; n = 9.Notes: *p < 0.05 when compared to uncoated titanium; **p < 0.01 and ***p < 0.1 when compared with large grain size nanocrystalline HA (prepared by sintering at 700°C) with 0.001 mg/ml HRN-K1 coated on titanium.

Mentions: Results from the cytocompatibility tests provided the first evidence of greater osteoblast adhesion on nanocrystalline HA/HRN coatings on titanium compared with uncoated titanium (Figure 6). Specifically, the small and middle grain sizes of nanocrystalline HA/HRN coatings increased osteoblast adhesion by 29.3% and 36.3% on titanium compared with uncoated titanium, respectively. At the same time, the small and middle grain size nanocrystalline HA/HRN coatings also increased osteoblast adhesion more than on the large grain size nanocrystalline HA/HRN coatings. In fact, it has been demonstrated that nanophase materials improved specific protein (such as fibronectin and vitronectin) interactions which contributed to enhanced osteoblast functions on nanophase materials compared with large grain size conventional materials (Webster et al 2000). For example, Webster and colleagues (2000) showed that there was significantly enhanced osteoblast adhesion on bulk nanophase HA (67 nm) compared with conventional HA (179 nm HA) due to greater amounts of vitronectin (a protein known to mediate anchorage-dependent cell adhesion [Webster 2001]) adsorption.


Biomimetic helical rosette nanotubes and nanocrystalline hydroxyapatite coatings on titanium for improving orthopedic implants.

Zhang L, Chen Y, Rodriguez J, Fenniri H, Webster TJ - Int J Nanomedicine (2008)

Osteoblast adhesion on HA and HRN-K1-coated titanium. Data are mean ±SEM; n = 9.Notes: *p < 0.05 when compared to uncoated titanium; **p < 0.01 and ***p < 0.1 when compared with large grain size nanocrystalline HA (prepared by sintering at 700°C) with 0.001 mg/ml HRN-K1 coated on titanium.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2626930&req=5

f6-ijn-3-323: Osteoblast adhesion on HA and HRN-K1-coated titanium. Data are mean ±SEM; n = 9.Notes: *p < 0.05 when compared to uncoated titanium; **p < 0.01 and ***p < 0.1 when compared with large grain size nanocrystalline HA (prepared by sintering at 700°C) with 0.001 mg/ml HRN-K1 coated on titanium.
Mentions: Results from the cytocompatibility tests provided the first evidence of greater osteoblast adhesion on nanocrystalline HA/HRN coatings on titanium compared with uncoated titanium (Figure 6). Specifically, the small and middle grain sizes of nanocrystalline HA/HRN coatings increased osteoblast adhesion by 29.3% and 36.3% on titanium compared with uncoated titanium, respectively. At the same time, the small and middle grain size nanocrystalline HA/HRN coatings also increased osteoblast adhesion more than on the large grain size nanocrystalline HA/HRN coatings. In fact, it has been demonstrated that nanophase materials improved specific protein (such as fibronectin and vitronectin) interactions which contributed to enhanced osteoblast functions on nanophase materials compared with large grain size conventional materials (Webster et al 2000). For example, Webster and colleagues (2000) showed that there was significantly enhanced osteoblast adhesion on bulk nanophase HA (67 nm) compared with conventional HA (179 nm HA) due to greater amounts of vitronectin (a protein known to mediate anchorage-dependent cell adhesion [Webster 2001]) adsorption.

Bottom Line: Some of the nanocrystalline HA formed dense coatings with HRNs on titanium.More importantly, results demonstrated enhanced osteoblast adhesion on the HRN/nanocrystalline HA-coated titanium compared with conventional uncoated titanium.Among all the HRN/nanocrystalline HA coatings tested, osteoblast adhesion was the greatest when HA nanometer particle size was the smallest.

View Article: PubMed Central - PubMed

Affiliation: Division of Engineering, Brown University, Providence, RI 02912, USA.

ABSTRACT
Natural bone consists of hard nanostructured hydroxyapatite (HA) in a nanostructured protein-based soft hydrogel template (ie, mostly collagen). For this reason, nanostructured HA has been an intriguing coating material on traditionally used titanium for improving orthopedic applications. In addition, helical rosette nanotubes (HRNs), newly developed materials which form through the self-assembly process of DNA base pair building blocks in body solutions, are soft nanotubes with a helical architecture that mimics natural collagen. Thus, the objective of this in vitro study was for the first time to combine the promising attributes of HRNs and nanocrystalline HA on titanium and assess osteoblast (bone-forming cell) functions. Different sizes of nanocrystalline HA were synthesized in this study through a wet chemical precipitation process following either hydrothermal treatment or sintering. Transmission electron microscopy images showed that HRNs aligned with nanocrystalline HA, which indicates a high affinity between both components. Some of the nanocrystalline HA formed dense coatings with HRNs on titanium. More importantly, results demonstrated enhanced osteoblast adhesion on the HRN/nanocrystalline HA-coated titanium compared with conventional uncoated titanium. Among all the HRN/nanocrystalline HA coatings tested, osteoblast adhesion was the greatest when HA nanometer particle size was the smallest. In this manner, this study demonstrated for the first time that biomimetic HRN/nanocrystalline HA coatings on titanium were cytocompatible for osteoblasts and, thus, should be further studied for improving orthopedic implants.

Show MeSH
Related in: MedlinePlus