Today, we received an interesting inquiry from Velentium Medical, a company inquiring about our supply of biocompatible magnet wires and Litz wires, specifically those made of silver or gold, or other biocompatible insulation solutions. This requirement is related to wireless charging technology for implantable medical devices.
Tianjin Ruiyuan Electrical Equipment Co., Ltd. has encountered such inquiries before and has provided customers with high-quality solutions. The Ruiyuan Laboratory has also conducted the following research on gold, silver, and copper as bioimplantable materials:
In implantable medical devices, the biocompatibility of materials depends on their interaction with human tissues, including factors such as corrosion resistance, immune response, and cytotoxicity. Gold (Au) and silver (Ag) are generally considered to have good biocompatibility, while copper (Cu) has poor biocompatibility, for the following reasons:
1.Biocompatibility of Gold (Au)
Chemical inertness: Gold is a noble metal that hardly oxidizes or corrodes in the physiological environment and does not release a large number of ions into the body.
Low immunogenicity: Gold rarely causes inflammation or immune rejection, making it suitable for long-term implantation.
2.Biocompatibility of Silver (Ag)
Antibacterial property: Silver ions (Ag⁺) have broad-spectrum antibacterial effects, so they are widely used in short-term implants (such as catheters and wound dressings).
Controllable release: Although silver will release a small amount of ions, reasonable design (such as nano-silver coating) can reduce toxicity, exert antibacterial effects without seriously damaging human cells.
Potential toxicity: High concentrations of silver ions may cause cytotoxicity, so it is necessary to carefully control the dosage and release rate.
3.Biocompatibility of Copper (Cu)
High chemical reactivity: Copper is easily oxidized in the body fluid environment (such as forming Cu²⁺), and the released copper ions will trigger free radical reactions, leading to cell damage, DNA breakage, and protein denaturation.
Pro-inflammatory effect: Copper ions can activate the immune system, causing chronic inflammation or tissue fibrosis.
Neurotoxicity: Excessive copper accumulation (such as Wilson’s disease) can damage the liver and nervous system, so it is not suitable for long-term implantation.
Exceptional application: The antibacterial property of copper allows it to be used in short-term medical devices (such as antibacterial surface coatings), but the release amount must be strictly controlled.
Key Summary
| Characteristics | Gold （AU） | Silver (Ag) | Copper (Cu) |
| Corrosion resistance | Extremely strong (inert) | Medium (Slow release of Ag+) | Weak (Easy release of Cu²+) |
| Immune response | Almost none | Low (Controllable time) | High (Pro-inflammatory) |
| Ctotoxicity | None | Medium-high (Depends on concentration) | High |
| Main uses | Long-term implanted electrodes/prostheses | Antibacterial short-term implants | Rare (Requires special treatment) |
Conclusion
Gold and silver are preferred for medical implant materials due to their low corrosivity and controllable biological effects, while copper’s chemical activity and toxicity limit its application in long-term implants. However, through surface modification (such as oxide coating or alloying), the antibacterial property of copper can also be utilized to a limited extent, but safety must be strictly evaluated.
Post time: Jul-18-2025