Improvement of corrosion resistance and biocompatibility of WE43 magnesium alloy treated by titanium and oxygen dual plasma implantation

Dear Colleague: We are happy to announce that the website, abstract submission, and registrations are open for the next 8 International Symposium on Degradable Metals (http://conferium.us6.list­manage2.com/track/click?u=bac668b7d9d03819c632c5e5b&id=3ea9894b94&e=5849ee5868), which will be held in l’Esterel, Montreal, Canada from May 14 to 17, 2016. Special arrangements were done to held the 8 Biometal2016 rightly before the 10 World Biomaterials Congress (http://conferium.us6.list­ manage1.com/track/click?u=bac668b7d9d03819c632c5e5b&id=0e2051925a&e=5849ee5868), which will be held in Montreal May 17 to 22, 2016. With more than 4000 delegates expected, and more than 3500 abstracts submitted, the 10 World Biomaterials Congress (http://conferium.us6.list­ manage.com/track/click?u=bac668b7d9d03819c632c5e5b&id=00ddde22f8&e=5849ee5868) will be the biomaterial event of the year! In particular, on May 17 after lunch, a bus will bring all delegates from the 8 Biometal 2016 in l’Esterel to Montreal Convention Center (Palais des Congrès) where the 10 WBC2016 will be held. Please consider to attend both conferences, you will have a great portrait of what is going on nowadays in biodegradable metals and biomaterials! LEsterel is located in the countryside region of Montreal, and it is the perfect location for kayak, canoeing, trekking, golfing, horse­riding, and others. The 8 Biometal 2016 will kept his traditional flavor aiming to mix an high scientific experience with a relaxed and informal environment, thus stimulating learning and networking. Please note the deadlines for submitting abstracts is January 21, 2016. Full details by clicking here (http://conferium.us6.list­manage.com/track/click?u=bac668b7d9d03819c632c5e5b&id=ec95e3d61d&e=5849ee5868). We really hope to welcome you all, again, for the 8 Biometal 2016 in l’Esterel, Montreal, Canada. Friendly regards Diego Mantovani On behalf of the Organizing Committee, 8th Biometal 2016 th

Special arrangements were done to held the 8 Biometal2016 rightly before the 10 World Biomaterials Congress (http://conferium.us6.listmanage1.com/track/click?u=bac668b7d9d03819c632c5e5b&id=0e2051925a&e=5849ee5868), which will be held in Montreal May 17 to 22, 2016.With more than 4000 delegates expected, and more than 3500 abstracts submitted, the 10 World Biomaterials Congress (http://conferium.us6.listmanage.com/track/click?u=bac668b7d9d03819c632c5e5b&id=00ddde22f8&e=5849ee5868) will be the biomaterial event of the year!In particular, on May 17 after lunch, a bus will bring all delegates from the 8 Biometal 2016 in l'Esterel to Montreal Convention Center (Palais des Congrès) where the 10 WBC2016 will be held.
Please consider to attend both conferences, you will have a great portrait of what is going on nowadays in biodegradable metals and biomaterials!LEsterel is located in the countryside region of Montreal, and it is the perfect location for kayak, canoeing, trekking, golfing, horseriding, and others.
The 8 Biometal 2016 will kept his traditional flavor aiming to mix an high scientific experience with a relaxed and informal environment, thus stimulating learning and networking.
Please note the deadlines for submitting abstracts is January 21, 2016.
We really hope to welcome you all, again, for the 8 Biometal 2016 in l'Esterel, Montreal, Canada.

Improvement of corrosion resistance and biocompatibility of WE43 magnesium alloy treated by titanium and oxygen dual plasma implantation
Z Lin 1,2 , Y Zhao 3 , HM Wong 1,2 , KMC Cheung 1 , F Leung 1,2 , PK Chu 4 , KWK Yeung 1,2＊ INTRODUCTION: Magnesium alloy is a potential candidate for degradable orthopaedic implantation due to its degradability.However, rapid corrosion and subsequent severe hydrogen release under in vivo conditions limit its clinical application.Therefore, various methods e.g.alloying, coating, and heat treatment have been applied to reinforce its corrosion property.In this study, we have developed titanium and oxygen dual plasma immersion ion implantation (PIII) [1] technique to improve the corrosion resistance and biocompatibility of WE43 alloy.

METHODS:
The casted WE43 alloy was treated by titanium and oxygen dual implantation.For characterization of PIII-treated WE43 alloy, the atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS) were conducted to investigate surface chemical states and morphology of the PIII-treated WE43 alloy.In order to systematically examine corrosion resistance of the untreated and PIII-treated alloys, immersion and electrochemical tests in the simulated body fluid (SBF) at 37℃ were also carried out.The biocompatibility of PIII-treated WE43 alloy was evaluated by MTT, ALP assays and cell attachment analysis cultured with mouse osteoblastic cells.

RESULTS:
The XPS and AFM results indicated that the surface of WE43 magnesium alloy appeared a dense TiO 2 protective film with the thickness of about 120nm created by titanium and oxygen dual implantation.The electrochemical tests in SBF showed that the PIII-treated WE43 alloy exhibited excellent performance of corrosion resistance.Its electrochemical impedance increased eighty times approximately, while corrosion density sharply dropped in the untreated group.Moreover, the TiO 2 protective film could still reduce corrosion and the subsequent Mg ion release effectively in comparison with the untreated alloy after three days of immersion in SBF.It was an evidence that the created dense TiO 2 film could suppress rapid corrosion of WE43 magnesium alloys.The WE43 alloy treated by Ti &O dual implantation exhibited achieved higher cell viability and ALP activity.Furthermore, the morphology of cells flattened and more F-actins were observed on the surface of PIII-treated WE43 alloy while culturing with MC3T3-E1 preosteoblasts, indicating that the cyto-compatibility of WE43 alloys can be significantly improved by titanium and oxygen dual PIII treatment.

Fig. 1
Fig. 1(a) The cell viability and (b) ALP assay of MC3T3-El preosteoblasts cultured with the extracts of PIII-treated WE43 alloy that immersed in DMEM for 24h) *denotes the significant difference between PIII-treated WE43 alloy and untreated WE43 alloy(p<0.05)

1
Dept. of Orthopaedics and Traumatology, The University of Hong Kong, Pokfulam, Hong Kong, China. 2 Shenzhen Key Laboratory for Innovative Technology in Orthopaedic Trauma, The University of Hong Kong Shenzhen Hospital, Futian District, Shenzhen, China. 3Center for Human Tissues and Organs Degeneration, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China. 4Dept. of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.