[Effect of surface modification on biotribological properties of ultra-high molecular weight polyethylene artificial joints].

Friction and wear of ultra-high molecular weight polyethylene is a major cause of artificial joint failure. According to mechanism of surface modification method, friction reduction and wear-resistance properties of UHMWPE were improve by several kinds of surface modification methods. Meanwhile, this do not damage the internal structure and properties of UHMWPE. In the process, condition is easy to control and operation is simple. However, reaction time of radiation crosslinking method is too long, the material will be oxidized embrittlement; Monomer itself homopolymerization are seriously in the process of surface grafting; The injection layer of ion implantation methods is very thin and easy to be destroyed. Objective in order to provide a reference for further research on the biotribological properties of ultra-high molecular weight polyethylene artificial joints. At present, as the researches of UHMWPE material main focus on abrasion resistance, and application in the clinical trial is the focus of research, it has a wide prospect in the future.

[Research on repair strategies for articular cartilage defects].

Articular cartilage damage is very common in clinical practices. Due to the low self-healing abilities of articular cartilage, the repair strategies for articular cartilage such as arthroscopic lavage and debridement,osteaochondral or chondrocytes transplantation, tissue engineering and hydrogel based artificial cartilage materials are the primary technologies of repairing articular cartilage defect. In this paper,the main repair strategies for the articular cartilage damage and the advantages or disadvantages of each repair technology are summarized. The arthroscopic lavage and debridement is successful in treating the early stage of osteoarthritis. Osteochondral and chondrocytes transplantation are beneficial to treat small full thickness defects. The technology of tissue engineering becomes a new method to heal articular cartilage damage, but the major problem is the absence of bonding strength between the implants and natural defect surfaces. Hydrogel based artificial cartilage possesses similar bio-mechanical and bio-tribological performances to that of natural articular cartilage. However, both bioactivity and interfacial bonding strength between the implant and natural cartilage could be further improved. How to simultaneously optimize the mechanical and bioactive as well as biotribological properties of hydrogel based materials is a focus problem concerned.

Cubic and doubly-fused cubic samarium clusters from Sm(II)-mediated reduction of organic azides and azobenzenes.

A polynuclear samarium imido complex [(L)Sm(4)(µ(3)-NSiMe(3))(4)] (2) featuring a cubane-like cluster has been synthesized from the reaction of an organic azide and a samarium(II) complex [(L)SmI(2)Li(2)(THF)(Et(2)O)(2)] (1). In addition, this divalent samarium starting material (1) reacts with azobenzene to give the first example of a well-defined doubly-fused cubic imido-cluster [(L)Sm(6)(µ(3)-NPh)(4)(µ(4)-NPh)(2)I(2)(THF)(2)] (4) in addition to a major cubic complex [(L)Sm(4)(µ(3)-NPh)(4)] (3).

A heterometallic sandwich complex of europium(II) for luminescent studies.

A divalent europium complex [(L(Ph))(2)Eu{K(THF)(2)}(2)] (L(Ph) = Ph(2)Si(NAr)(2), Ar = 2,6-(i)Pr(2)C(6)H(3)) (THF = Tetrahydrofuran) (2), which has a sandwich structure with potassium-arene π interactions, was synthesized in high yield via a one-pot process. This complex has been fully characterized, and luminescent studies showed that the 528 nm emission peak can be attributed to the 4f-5d transition of Eu(2+).