Mechanical testing and osteointegration of titanium implant with calcium phosphate bone cement and autograft alternatives

Presenting dual-functional peptides on implant surface to direct in vitro osteogenesis and in vivo osteointegration

The complex biological process of osseointegration and the bio-inertness of bone implants are the major reasons for the high failure rate of long-term implants, and have also promoted the rapid development of multifunctional implant coatings in recent years. Herein, through the special design of peptides, we use layer-by-layer assembly technology to simultaneously display two peptides with different biological functions on the implant surface to address this issue. A variety of surface characterization techniques (ellipsometry, atomic force microscopy, photoelectron spectroscopy, dissipation-quartz crystal microbalance) were used to study in detail the preparation process of the dual peptide functional coating and the physical and chemical properties, such as the composition, mechanical modulus, stability, and roughness of the coating. Compared with single peptide functional coatings, dual-peptide functionalized coatings had much better performances on antioxidant, cellular adhesion in early stage, proliferation and osteogenic differentiation in long term, as well as in vivo osteogenesis and osseointegration capabilities. These findings will promote the development of multifunctional designs in bone implant coatings, as a coping strategy for the complexity of biological process during osteointegration.

Micro-patterned titanium coatings with a grid-like structure doped with vancomycin against bacteria and affecting osteogenic differentiation

The present study aimed to investigate the effects of micro-patterned titanium coatings doped with vancomycin on antibacterial activity and osteogenic differentiation and to improve the bioactivity of the inert titanium..

Effect of methotrexate on the mechanical properties and microstructure of calcium phosphate cement

Calcium phosphate cement (CPC) is widely used as an antitumor bone-filling material. Methotrexate (MTX) is recognized as an effective chemotherapy medicine. The current study examined the effects of MTX on the mechanical properties and microstructure of CPC. Methotrexate-loaded CPC at mass ratios of 0%, 0.1%, 0.2%, and 0.5% were designated as groups A, B, C, and D, respectively, and were pressed into precast cylindrical molds. Solidification time, axial compressive strength, transverse compressive strength, and rotational tensile strength were measured, and scanning electron microscopy images were captured before and after MTX-CPC microstructure changes occurred. Average initial and final setting times increased gradually with increasing drug concentration, but this increase was not significant among the groups. Average axial transverse compressive strength and rotational tensile strength of groups B and C were not significantly different from those of group A (P>.05); however, there was a significant difference in these properties between groups A and D (P<.05). Scanning electron microscopy observations showed a porous crystalline structure. The addition of MTX to CPC does not significantly affect the basic crystal structure and setting time of CPC. Adding MTX at mass ratios of 0.1% and 0.2% to CPC does not lead to a significant difference in mechanical strength and can therefore be applied in clinical practice. This study may shed some light on the future application of MTX-loaded CPC in the treatment of bone defects after tumor excision.