What are the requirements for implantable silicone?

What are the requirements for implantable silicone?
Implantable silicone belongs to medical grade silicone. Compared with ordinary silicone, it has strict requirements in many aspects, as follows:
Biocompatibility: Medical silicone must have good biocompatibility. After implantation, it will not cause obvious immune response, allergic reaction, inflammatory reaction or toxic reaction. It needs to be able to coexist peacefully with human tissues, not be recognized as a foreign body by the human immune system and attacked, and minimize the stimulation and adverse effects on surrounding tissues. For example, it will not cause inflammatory symptoms such as redness, swelling, pain, and fever of local tissues, nor will it cause systemic allergic reactions such as rashes and breathing difficulties.
Chemical stability: It has a high degree of chemical stability. In the complex physiological environment of the human body (such as body temperature, acid-base environment, immersion in various body fluids, etc.), it does not react chemically, decompose, or release harmful substances. It can maintain its physical and chemical properties for a long time, and will not degrade, swell or deteriorate due to contact with human tissues and body fluids, thereby ensuring the safety and effectiveness of the implant.
Purity: Silicone implantable in the human body requires extremely high purity and extremely low impurity content. The presence of impurities may increase the toxicity of silicone or cause adverse reactions in the human body. Therefore, during the production process, special processes and strict quality control are required to remove various impurities and ensure that the purity of silicone meets medical standards.
Physical properties: It has appropriate physical properties, such as certain elasticity, strength and toughness, to meet different implantation needs. For example, silicone used for breast augmentation needs to have good elasticity and softness to simulate the touch of real breasts; while silicone implants used in orthopedics may require higher strength and wear resistance to withstand the weight of the human body and the pressure during activities. At the same time, its physical indicators such as hardness, density, and tensile strength also need to meet the corresponding standards and requirements.
Sterility: Silicone implanted in the human body must be absolutely sterile to prevent infection. During the production, packaging, storage and use, strict aseptic operation and sterilization measures need to be taken, such as high temperature and high pressure sterilization, radiation sterilization and other methods to ensure that the silicone implant is free of any microbial contamination before implantation into the human body.
Processability: It can be processed into various shapes and sizes to adapt to different implant sites and clinical needs. For example, according to the individual differences of patients and surgical requirements, silicone can be processed into prostheses of specific shapes, such as ear and nose prostheses for plastic surgery. At the same time, the processing process cannot affect the performance and quality of silicone to ensure that it can function normally after implantation in the human body.
Sterilizability: It can withstand commonly used disinfection and sterilization methods, such as high temperature and high pressure, radiation, etc. mentioned above. During the disinfection and sterilization process, its physical and chemical properties will not change significantly, no harmful degradation products will be produced, and it still maintains good biocompatibility and other properties.