Material analysis: application of PEEK materials in medical implantation and medical device industry

Peek (polyether ether ketone) material has excellent high temperature resistance, self lubrication, corrosion resistance, flame retardancy, mechanical properties, electrical properties, hydrolysis resistance, weather resistance and so on.

Due to its excellent comprehensive properties, peek can replace metal, ceramics and other traditional materials in many special fields, making it one of the most popular high-performance engineering plastics. At present, peek is mainly used in aerospace, automotive industry, electronic and electrical, medical machinery and other fields.

In recent years, with the rapid development of materials science, medical polymer materials have gradually become the most widely used and the largest amount of materials. Polyether ether ketone (PEEK), as a new type of medical implant material, stands out among many medical materials by virtue of its excellent characteristics, and is more and more used in plastic surgery, cardiovascular, artificial spine and other fields:

1.PEEK material for medical implantation

Excellent performance, is the closest to the bone material

Biocompatibility is the most basic factor to measure whether a material is suitable for human implantation. The material must have no cytotoxicity, mutagenicity, carcinogenicity, and allergy. Implant grade peek has been tested for biocompatibility in foreign independent testing institutions in strict accordance with the requirements of ISO10993. The results showed that the implanted peek had excellent biocompatibility without any side effects.

The famous wolf's law points out that bone grows where it is needed and absorbs when it is not needed, that is, the growth, absorption and reconstruction of bone are related to the stress state of bone. Because the elastic modulus of the metal is much higher than that of the bone, when the metal is implanted into the human body, it bears most of the mechanical load, and the load on the bone is reduced, forming a stress shielding effect. The consequence is to delay the healing of the bone. In the long run, the bone becomes loose or even degenerate. On the contrary, the elastic modulus of PEEK is very close to that of bone, and the stress of bone is not completely borne by the implant, which makes the bone healthier.

Repairing skull to avoid embarrassment of cold winter and hot summer

Researchers found that peek is the clinical skull repair material with the closest performance to human bone at present. Compared with commonly used titanium alloy, peek has similar physical properties to human bone, strong texture and no risk of stress depression; Good heat insulation, can avoid cold in winter and hot in summer. Although titanium alloy has good heat transfer performance, it is a disadvantage for patients. When patients are affected by the external temperature difference, the cranial environment changes, which will affect the comfort. For example, when patients come from warm indoor to cold outdoor in winter, the excellent thermal conductivity of titanium skull plate will make patients feel pain and discomfort. Peek has good thermal insulation, avoiding the embarrassing situation of titanium alloy mesh cold in winter and hot in summer.

Peek discards the defects of conventional cranioplasty materials such as plexiglass, bone cement and titanium alloy, such as strong rejection reaction, poor shaping effect, poor heat insulation effect, poor comfort and poor postoperative X-ray permeability, so as to avoid discomfort caused by temperature difference; 3D printing technology is used for molding, with perfect appearance and good histocompatibility; The mechanical properties are close to human bone. It can be predicted that this new material will be the first choice for cranioplasty.

Repair the spine to reduce complications

In recent years, the incidence rate of lumbar and cervical diseases has increased year by year, and tends to be younger. There are more than 200 million patients with lumbar spondylosis and 200 million patients with cervical spondylosis in China. If the patient has a degenerative disease of the spine, the doctor will recommend that the diseased disc be removed and replaced with a prosthesis called "interbody fusion cage".

At present, the common interbody fusion cages in China are titanium alloy cage and peek cage. Due to the high elastic modulus of titanium alloy, it is more likely to delay fusion due to stress shielding after surgery, and it is gradually replaced by peek fusion cage in recent years. The fusion cage made of PEEK material can be compatible with X-ray photography and magnetic resonance imaging, and has low elastic modulus, which can avoid the complications of autograft and the defects of allograft.

The properties of modified peek are more powerful. The adsorption and cross-linking of type I collagen can improve the surface hydrophobicity of PEEK materials and the adhesion and proliferation of cells. The modified materials have better biocompatibility and bone fusion ability than the unmodified materials.

Dental accessories for patients to wear more comfortable

Peek is widely used in the field of Stomatology because of its excellent chemical stability and resistance to most chemical agents. Peek materials are mainly used in dental implant accessories, such as temporary abutment, healing cap, healing abutment and so on. Compared with metal, zirconia and alumina, peek is more accurate without sintering; Low density, light weight, comfortable for patients; Soft texture, has a shock absorption effect on occlusion.

The above information comes from: China Chemical News

In addition to medical implant accidents, peek is also widely used in the field of medical devices

Peek collimator bracket for intramedullary nail