Antibacterial property, angiogenic and osteogenic activity of Cu-incorporated TiO 2 coating

47 Pages·2014·2.08 MB·English

Journal of
M aterials Chemistry B
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Page 1 of 45 Journal of Materials Chemistry B
People's Hospital Affiliated to Shanghai Jiao Tong University, School of
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Medicine, Shanghai Key Laboratory of Stomatology, 639 Zhizaoju Road, p
Shanghai 200011, PR China,
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Journal of Materials Chemistry B Page 2 of 45
Textual abstract
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Copper-incorporated TiO coating on titanium surface can significantly enhance the
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antimicrobial, angiogenic and osteogenic activities.
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Page 3 of 45 Journal of Materials Chemistry B

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Copper-incorporated TiO2 coating on titanium surface can significantly enhance the antimicrobial, angiogenic t
and osteogenic activities. s
40x26mm (600 x 600 DPI) i
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Journal of Materials Chemistry B Page 4 of 45
Antibacterial property, angiogenic and osteogenic activity of
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Cu-incorporated TiO coating
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4 Qianju Wua, b,1, Jinhua Lic,1, Wenjie Zhanga,b, Haixin Qiana, Wenjun Shea, Hongya n
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5 Panb, Jin Wena,b, Xiuli Zhangb, Xuanyong Liuc,* and Xinquan Jianga,b,* M
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7 a Department of Prosthodontics, Ninth People’s Hospital affiliated to Shanghai Jiao pt
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8 Tong University, School of Medicine, 639 Zhizaoju Road, Shanghai 200011, China. c
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9 b Oral Bioengineering Lab, Ninth People's Hospital Affiliated to Shanghai Jiao Tong A
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10 University, School of Medicine, Shanghai Key Laboratory of Stomatology, 639
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11 Zhizaoju Road, Shanghai 200011, China. r
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12 c State Key Laboratory of High Performance Ceramics and Superfine Microstructure, i
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13 Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, e
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14 China.
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16 Corresponding Authors: r
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18 Prof. Xinquan Jiang M
19 Department of Prosthodontics, Ninth People’s Hospital affiliated to Shanghai Jiao Tong University,
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20 School of Medicine, 639 Zhizaoju Road, Shanghai 200011, China.
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21 E-mail: [email protected]
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22 Tel.: [phone]. Fax: [phone]. r
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24 Prof. Xuanyong Liu
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1 State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai
2 Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China. t
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3 E-mail: [email protected] i
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4 Tel.: [phone]. Fax: [phone].
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6 1 These authors contributed equally to this work. a
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Journal of Materials Chemistry B Page 6 of 45
1 Abstract
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2 Numerous efforts have been made to modify the surface topography and chemical
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3 composition of biomedical implants in order to enhance the antibacterial ability and
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4 the osteointegration between implants and surrounding bone tissue. In the present n
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5 work, copper-incorporated TiO2 coatings were fabricated by combining micro-arc M
6 oxidation and hydrothermal treatment together to functionalize the surface of Ti d
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7 implants. The as-prepared surfaces exhibited a hierarchical structure comprising p
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8 nanoneedles nearly perpendicular to the microrough surface of TiO2 coating. The c
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9 Cu-loaded TiO2 coating possessed strong antimicrobial ability against Gram-negative A
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10 Escherichia coli. In vitro cytocompatibility evaluation suggests that no significant
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11 cytotoxicity appeared on Cu-incorporated TiO2 coating. Furthermore, the addition of r
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12 copper element could stimulate the expression of angiogenic genes including i
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13 hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) e
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14 in rat bone marrow stem cells (BMSCs). Meanwhile, they tended to undergo
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15 osteogenic differentiation, indicated by the up-regulation expression of osteogenic
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16 markers and the higher level of alkaline phosphatase activity. This study provides r
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17 insight for the surface modification of biomedical Ti-based implants. To our best a
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18 knowledge, this is a successful attempt for the first time to combine micro-arc
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19 oxidation and hydrothermal treatment to introduce copper nutrient element to
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20 functionalize Ti-based implant surfaces with enhanced angiogenesis potential, n
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21 osteostimulation and antimicrobial property that can better meet the clinical needs.
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22 Keywords: titania; copper; antibacterial; angiogenesis; osteogenesis; stem cells
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Page 7 of 45 Journal of Materials Chemistry B
1 1. Introduction
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2 Oral implantation is the most innovative and superior treatment for both partially
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3 and completely edentulous patients due to the stability and superiority compared with
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4 the removable dentures, which often cause leveraging, allergic reaction to the n
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5 materials used and alveolar bone resorption for a long term. Commercially titanium M
6 and its alloys have been extensively used for dental and orthopedic implants because d
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7 of their intrinsic biocompatibility and excellent mechanical strength.1 However, pt
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8 Ti-based materials cannot achieve sufficient osseointegration due to the suboptimal c
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9 osteoconductivity.2 Moreover, the surface of Ti-based implants may provide substrates A
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10 for bacteria to adhere, colonize, and subsequently form biofilms, leading to the
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11 infections at the implant sites, which is another main reason for surgery failure.3 r
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12 In order to solve the above problems, increasing researches have focused on the i
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13 surface loading of antibacterial agents to prevent bacterial adhesion at the implant e
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14 sites and the surface modification to enhance ossteointegration between implant
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15 surface and surrounding bone tissue.4 As is known, copper (Cu) has excellent
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16 antibacterial properties against numerous bacteria,4-6 and it delivered by far the best r
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17 compromise between antibacterial effectiveness and cytotoxicity when compared with a
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18 other antibacterial ions such as Zn, Ag.7 Incorporation of copper into medical devices
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19 to enhance their antibacterial activity has drawn considerable attentions. Ren et al. had
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20 developed the Cu-bearing stainless steel, which not only maintained the excellent n
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21 mechanical and corrosion-resistant properties, but also showed strong antibacterial
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22 ability by inhibiting the formation of bacterial biofilms on surface.8 Additionally, it
Journal of Materials Chemistry B Page 8 of 45
1 has been demonstrated that there is an intimate relationship between copper levels and
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2 vascularization by stimulating the proliferation of endothelial cells and promoting the
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3 up-regulation of VEGF,9, 10 which is a key factor for vascularization. Moreover,
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4 copper takes part in bone metabolism and is beneficial to the bone formation.11 n
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5 Studies have reported that trace amount of copper (50 μM) can promote the M
6 osteogenic ability of MSC obtained from postmenopausal women.12 Ewald et al. d
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7 found that Cu-CPC could enhance the cell activity and proliferation of osteoblastic p
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8 cells.13 It can offer a promising alternative to incorporate copper ions into c
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9 biomaterials in order to stimulate cellular activity for improving bone healing. A
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10 However, extra attention should be paid to the cytotoxic effects of the copper
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11 ions released from biomedical devices.14 Hence, it is essential to establish a unique r
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12 sustained release platform that can keep copper ions in a state of trace amount to i
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13 reduce the adverse effects against the surrounding tissue in order to promote implant e
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14 ingrowth and maintain the antibacterial properties.
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15 Applying the approach of micro-arc oxidation (MAO) to modify the implant
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16 surface to enhance its biocompatibility and osteoconductivity has been widely r
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17 investigated. MAO, based on the principle of plasma-electrolytic oxidation, forms a a
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18 rough, firmly adherent TiO2 layer on Ti surface.15, 16 And meanwhile, bioactive
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19 elements such as calcium (Ca), phosphorus (P), which are compositions of bone, can
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20 electrolytically deposit into the surface layer, and the incorporation of Ca or P n
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21 elements into TiO2 film can enhance the activity of osteoblastic cells and promote the
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22 more rapid formation of new bone in vivo.17 Moreover, Studies have demonstrated the
Page 9 of 45 Journal of Materials Chemistry B
1 inorganic ions incorporated into porous TiO2 coating fabricated by MAO could show
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2 a sustained release pattern, instead of burst release.18, 19 Taking these into
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3 consideration, it is expected that the superiority and biocompatibility of
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4 calcium/phosphate-rich TiO2 coating could “compensate” the cytotoxcity of copper n
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5 ions, making a balance between antibacterial property and biocompatibility. M
6 In the present work, hierarchical calcium/phosphate-rich TiO2 coating with d
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7 micro/nano topography was fabricated on metallic Ti surface via MAO method and p
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8 subsequently copper ions were doped into the MAO-treated surface by hydrothermal c
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9 treatment. The antibacterial activity of the coatings against Gram-negative A
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10 Escherichia coli (E. coli) was examined. Furthermore, BMSCs were seeded onto the
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11 modified surfaces to investigate whether the combination of TiO2 coating with copper r
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12 ions could possess favorable cytocompatibility, angiogenesis and osteogenesis i
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13 potentials. This study may provide a new sight for the better understanding and e
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14 designing of copper incorporated-based surface modification for biomedical Ti-based
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15 implants to improve their biological performances and success rates.
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17 2. Materials and methods a
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19 2.1. Samples preparation and modification
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20 Commercially pure Ti (Cp Ti, Grade 1, > 99.85 wt% purity) foils with n
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21 dimensions of 10 mm × 10 mm × 1 mm or 20 mm × 20 mm × 1 mm were
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22 ultrasonically cleaned several times, then pickled in 5 wt% oxalic acid solution at 100