Journal Article

Alloying design of biodegradable zinc as promising bone implants for load-bearing applications

Dai, Kerong, Zheng, Yufeng, Lin, Wenjiao, Jia, Bo, Li, Guannan, Zhang, Zechuan, Qu, Xinhua, Zhu, Donghui, Yang, Hongtao

2020

Overview

Magnesium-based biodegradable metals (BMs) as bone implants have better mechanical properties than biodegradable polymers, yet their strength is roughly less than 350 MPa. In this work, binary Zn alloys with alloying elements Mg, Ca, Sr, Li, Mn, Fe, Cu, and Ag respectively, are screened systemically by in vitro and in vivo studies. Li exhibits the most effective strengthening role in Zn, followed by Mg. Alloying leads to accelerated degradation, but adequate mechanical integrity can be expected for Zn alloys when considering bone fracture healing. Adding elements Mg, Ca, Sr and Li into Zn can improve the cytocompatibility, osteogenesis, and osseointegration. Further optimization of the ternary Zn-Li alloy system results in Zn-0.8Li-0.4Mg alloy with the ultimate tensile strength 646.69 ± 12.79 MPa and Zn-0.8Li-0.8Mn alloy with elongation 103.27 ± 20%. In summary, biocompatible Zn-based BMs with strength close to pure Ti are promising candidates in orthopedics for load-bearing applications. Biodegradable implants are of great interest in orthopaedic applications but have been limited by low mechanical strength. Here, the authors examine systematically in detail the strengthening of biodegradable zinc by alloying with beneficial elements using mechanical, biodegradability and biocompatibility testing.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 14/19 / 14/34 / 147/135 / 639/301/1023/1026 / 639/301/54 / 64/86 / 692/700/806 / Absorbable Implants / Alloy systems / Alloying elements / Alloys / Alloys - chemistry / Animals / Binary alloys / Biocompatibility / Biodegradability / Biodegradable materials / Biodegradation / Biomedical materials / Bone healing / Bone implants / Bone-Implant Interface - diagnostic imaging / Calcium / Cell Line / Copper / Elongation / Femur - diagnostic imaging / Femur - surgery / Fracture Fixation, Internal - instrumentation / Heavy metals / Human Umbilical Vein Endothelial Cells / Humanities and Social Sciences / Humans / In vivo methods and tests / Internal Fixators / Magnesium / Manganese / Materials Testing / Mechanical properties / Microscopy, Electron, Scanning / multidisciplinary / Optimization / Orthopedics / Osseointegration / Osteoblasts / Osteogenesis / Polymers / Prosthesis Design / Rats / Science / Science (multidisciplinary) / Silver / Strontium / Surgical implants / Tensile Strength / Titanium / Ultimate tensile strength / Weight-Bearing / X-Ray Microtomography / Zinc / Zinc - chemistry / Zinc base alloys