Introduction: Surface modification of biomaterials with balanced biological properties, i.e. inhibit the adhesion of pathogenic bacteria but promote the positive functions of bone cells, is highly desired for orthopedic and dental implants. Ion implantation, capable of forming new phases or alloys beyond the normal thermodynamic constraints[1], will facilitate realizing such designs in surface modifications. During the past years, by using the cathodic-arc-sourced metal plasma immersion ion implantation and deposition (MPIIID) technique, our group published more than 20 articles concerning improving the biological performance of various biomaterials[2]-[5].
Materials and Methods: MPIIID was applied to introduce silver and titanium onto titanium oxide and polyetheretherketone (PEEK) substrates, respectively. The physical and chemical characteristics of the MPIIID-treated materials were studied by various techniques, including transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The in vitro responses of both bacterial and mammalian cells were evaluated by using S. aureus (or E. coli) and bone marrow stem cells (BMSCs). The in vivo responses of bone tissues were revealed by bone defect and osteomyelitis models in rats.
Results and Discussion: The results demonstrated that the precipitation behavior of silver nanoparticles (Ag NPs) on titanium oxide (Figure 1) can be tailored by manipulating the atomic-scale heating effect in MPIIID, and a nano-porous layer can be constructed on PEEK (Figure 2) by taking advantage of the charging effect of MPIIID. So that good antimicrobial activity and/or excellent osteogenic property were evidenced on these MPIIID-treated materials.
Conclusion: Since developing of tactics that inhibit bacterial colonization as well as promote osseointegration is of great significance in clinic, MPIIID will be served as high impact technique for processing of orthopaedic and dental devices with better performances.
Figure 1 Silver nanoparticles (Ag NPs) with various size and distribution were fabricated on titanium oxide coatings by using silver plasma immersion ion implantation (Ag-PIII)[2].
Figure 2 The nano-porous layer fabricated on carbon-fiber-reinforced polyetheretherketone (PEEK) by using titanium plasma immersion ion implantation (Ti-PIII)[5].
This work is supported by the National Basic Research Program of China (973 Program, 2012CB933600), National Natural Science Foundation of China (31370962), Shanghai Committee of Science and Technology, China (14XD1403900), Shanghai Rising-Star Program (15QA1404100), Youth Innovation Promotion Association CAS (2015204), the Open Research Fund of State Key Laboratory of Bioelectronics, Southeast University.
References:
[1] PK Chu, J Chen, LP Wang, N Huang. Plasma-surface modification of biomaterials, Materials Science and Engineering R 2002, 36:143-206.
[2] H Cao, Y Qiao, X Liu, T Lu, T Cui, F Meng, PK Chu. Electron storage mediated dark antibacterial action of bound silver nanoparticles: Smaller is not always better, Acta Biomaterialia 2013, 9:5100-10.
[3] H Cao, Y Qiao , F Meng, X Liu. Spacing-Dependent Antimicrobial Efficacy of Immobilized Silver Nanoparticles. The Journal of Physical Chemistry Letters 2014, 5: 743-8.
[4] H Qin, H Cao, Y Zhao, C Zhu, T Cheng, Q Wang, X Peng, M Cheng, J Wang, G Jin, Yao Jiang, X Zhang, X Liu, PK. Chu, In vitro and in vivo anti-biofilm effects of silver nanoparticles immobilized on titanium, Biomaterials 2014,35:9114-25.
[5] T Lu, X Liu, S Qian, H Cao, Y Qiao, Y Mei, PK Chu, C Ding. Multilevel surface engineering of nanostructured TiO2 on carbon-fiber –reinforced polyetheretherketone. Biomaterials 2014, 35:5731-40.