title: Improving osteointegration and osteogenesis of three-dimensional porous Ti6Al4V scaffolds by polydopamine-assisted biomimetic hydroxyapatite coating.
abstract: Titanium alloys with various porous structures can be fabricated by advanced additive manufacturing techniques, which are attractive for use as scaffolds for bone defect repair. However, modification of the scaffold surfaces, particularly inner surfaces, is critical to improve the osteointegration of these scaffolds. In this study, a biomimetic approach was employed to construct polydopamine-assisted hydroxyapatite coating (HA/pDA) onto porous Ti6Al4V scaffolds fabricated by the electron beam melting method. The surface modification was characterized with the field emission scanning electron microscopy, energy dispersive spectroscopy, water contact angle measurement, and confocal laser scanning microscopy. Attachment and proliferation of MC3T3-E1 cells on the scaffold surface were significantly enhanced by the HA/pDA coating compared to the unmodified surfaces. Additionally, MC3T3-E1 cells grown on the HA/pDA-coated Ti6Al4V scaffolds displayed significantly higher expression of runt-related transcription factor-2, alkaline phosphatase, osteocalcin, osteopontin, and collagen type-1 compared with bare Ti6Al4V scaffolds after culture for 14 days. Moreover, microcomputed tomography analysis and Van-Gieson staining of histological sections showed that HA/pDA coating on surfaces of porous Ti6Al4V scaffolds enhanced osteointegration and significantly promoted bone regeneration after implantation in rabbit femoral condylar defects for 4 and 12 weeks. Therefore, this study provides an alternative to biofunctionalized porous Ti6Al4V scaffolds with improved osteointegration and osteogenesis functions for orthopedic applications.
authors.affiliation: †Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, People's Republic of China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Li
authors.affiliation: †Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Yang
authors.affiliation: †Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, People's Republic of China.
authors.forename: Xiaokang
authors.initials: X
authors.lastname: Li
authors.affiliation: ‡Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, Liaoning 110016, People's Republic of China.
authors.forename: Xing
authors.initials: X
authors.lastname: Zhang
authors.affiliation: †Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, People's Republic of China.
authors.forename: Cairu
authors.initials: C
authors.lastname: Wang
authors.affiliation: †Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, People's Republic of China.
authors.forename: Xiangfei
authors.initials: X
authors.lastname: Meng
authors.affiliation: †Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, People's Republic of China.
authors.forename: Yifeng
authors.initials: Y
authors.lastname: Pei
authors.affiliation: †Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, People's Republic of China.
authors.forename: Xiangli
authors.initials: X
authors.lastname: Fan
authors.affiliation: †Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, People's Republic of China.
authors.forename: Pingheng
authors.initials: P
authors.lastname: Lan
authors.affiliation: †Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, People's Republic of China.
authors.forename: Chunhui
authors.initials: C
authors.lastname: Wang
authors.affiliation: †Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, People's Republic of China.
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Li
authors.affiliation: †Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, People's Republic of China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Guo
mesh_terms: D000327:Adsorption; D000497:Alloys; D000818:Animals; D041702:BALB 3T3 Cells; D040761:Biomimetic Materials / Q000138:chemical synthesis; D049109:Cell Proliferation / Q000502:physiology*; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis*; D019544:Equipment Failure Analysis; D007211:Indoles / Q000737:chemistry; D008422:Materials Testing; D051379:Mice; D016348:Osseointegration / Q000502:physiology*; D010012:Osteogenesis / Q000502:physiology*; D011108:Polymers / Q000737:chemistry; D016062:Porosity; D011474:Prosthesis Design; D054457:Tissue Scaffolds; D014025:Titanium / Q000737:chemistry*
chemical_list: D000497:Alloys; D020099:Coated Materials, Biocompatible; D007211:Indoles; D011108:Polymers; C568283:polydopamine; C031462:titanium alloy (TiAl6V4); D014025:Titanium
keywords: hydroxyapatite; osteogenesis; osteointegration; polydopamine; porous titanium; surface modification