研究发现,氮化镓Non-Toxic, Biocompatible – Holds Promise For Biomedical Implants

Researchers from North Carolina State University and Purdue University have shown that the semiconductor material gallium nitride (GaN) is non-toxic and is compatible with human cells – opening the door to the material’s use in a variety of biomedical implant technologies.

GaN is currently used in a host of technologies, from LED lighting to optic sensors, but it is not in widespread use in biomedical implants. However, the new findings from NC State and Purdue mean that GaN holds promise for an array of implantable technologies – from electrodes used in neurostimulation therapies for Alzheimer’s to transistors used to monitor blood chemistry.

“第一个发现是，与其他被认为用于生物医学植入物的半导体材料不同，GAN没有毒性。这使环境和患者的风险降至最低。Ivanisevic是北卡罗来纳州材料科学与工程副教授，北卡罗来纳州州立大学和北卡罗来纳大学教堂山的联合生物医学工程计划副教授。

Researchers used a mass spectrometry technique to see how much gallium is released from GaN when the material is exposed to various environments that mimic conditions in the human body. This is important because gallium oxides are toxic. But the researchers found that GaN is very stable in these environments – releasing such a tiny amount of gallium that it is non-toxic.

The researchers also wanted to determine GaN’s potential biocompatibility. To do this they bonded peptides – the building blocks that make up proteins – to the GaN material. Researchers then placed peptide-coated GaN and uncoated GaN into cell cultures to see how the material and the cells interacted.

Researchers found that the peptide-coated GaN bonded more effectively with the cells. Specifically, more cells bonded to the material and those cells spread over a larger area.

“This matters because we want materials that give us some control over cell behavior,” Ivanisevic says. “For example, being able to make cells adhere to a material or to avoid it.

“One problem facing many biomedical implants, such as sensors, is that they can become coated with biological material in the body. We’ve shown that we can coat GaN with peptides that attract and bond with cells. That suggests that we may also be able to coat GaN with peptides that would help prevent cell growth – and keep the implant ‘clean.’ Our next step will be to explore the use of such ‘anti-fouling’ peptides with GaN.”

The paper, “Gallium Nitride is Biocompatible and Non-Toxic Before and After Functionalization with Peptides,” is forthcoming fromActa Biomaterialia并由博士合着学生Scott A. Jewett和Matthew S. Makowski；本杰明·安德鲁斯本科生；和迈克尔·J·曼弗拉（Michael J. Manfra） - 普渡大学（Purdue）。该研究由国家科学基金会资助。

NC州立材料科学与工程系和生物医学工程联合系是该大学工程学院的一部分。

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Note to Editors:The study abstract follows.

“Gallium Nitride is Biocompatible and Non-Toxic Before and After Functionalization with Peptides”

Authors: Scott A. Jewett, Matthew S. Makowski, Benjamin Andrews and Michael J. Manfra, Purdue University; Albena Ivanisevic, North Carolina State University

Published: online byActa Biomaterialia

Abstract:The toxicity of semiconductor materials can significantly hinder their use for in vitro and in vivo applications. Gallium nitride (GaN) is a material with remarkable properties which include excellent chemical stability. This work demonstrated that functionalized and etched GaN surfaces were stable in aqueous environments and leached a negligible amount of Ga in solution even in the presence of hydrogen peroxide. Also, GaN surfaces in cell culture did not interfere with nearby cell growth, and etched GaN promoted the adhesion of cells compared to etched silicon surfaces. A model peptide, “IKVAV,” covalently attached to GaN and silicon surfaces increased the adhesion of PC12 cells. Peptide terminated GaN promoted greater cell spreading and extension of neurites. The results suggest that peptide modified GaN is a biocompatible and non-toxic material that can be used to probe chemical and electrical stimuli associated with neural interfaces.