According to the application of silicone rubber in the medical, pharmaceutical, and health industries, it can be roughly summarized as organ or tissue substitutes for long-term indwelling in the human body, medical devices for short-term indwelling in the human body, plastic medical devices, drug release systems, external products, etc. These aspects are discussed separately below.
Organ or tissue substitutes left in the human body for a long time
Such organs or tissues include hydrocephalus drainage devices, and various artificial organs (such as artificial lungs, artificial joints, artificial retinal implants, artificial heart valves, etc.).
The hydrocephalus drainage device was one of the first silicone rubber implants in the world to be used as a treatment for the disease. In the 1950s, the world’s first silicone rubber hydrocephalus drainage device appeared. With this device, hydrocephalus can be directed into the thoracic or abdominal cavity, and the treatment effect is very good; it is still used in surgery to this day, and medical silicone rubber has always been the preferred manufacturing material for this device.
Since the beginning of the last century, medical companies around the world have used various materials to make artificial tendons. As a permanent replacement for tendons, artificial tendons must meet the following conditions: no foreign body reaction after implantation, good flexibility, and bendability, It does not deform and can be firmly combined with the receptor tendon. The joint part and the tendon itself can withstand a certain tensile force without breaking, and there is no adhesion to the surrounding tissue. It is easy to disinfect. The feasibility of repairing the flexor tendon with the material is relatively high; this is because the pseudosheath formed by wrapping the silicone rubber tube can prevent the adhesion of the recipient’s tendon to the surrounding tissue so that the patient can quickly restore function.
Auxiliary medical devices for short-term indwelling in the human body
Silicone rubber products are used as auxiliary medical devices in the human body for short-term indwelling in the body, which play the role of fluid rehydration, rescue, drainage and injection, anti-adhesion, or defoaming. Such devices include venous intubation, urinary catheter, arteriovenous fistula, abdominal dialysis Tubes, contact lenses, blood vessels, pressure relief tubes, chest drainage tubes, gastroscope sleeves, otitis media ventilation tubes, catheters, nasal cannulae, etc.
Key Components of medical silicone devices
These components include artificial heart-lung blood transfusion pump tubes, membrane artificial heart-lung machines, fetal suction devices and artificial blood circulation devices.
Applications in cosmetic surgery and restoration
In the past 20 years, silicone rubber has also been widely used in cosmetic and prosthetic surgery, such as: repairing facial defects with silicone rubber, treating defects in the outer ear, performing cosmetic surgery on the skull and chest, and repairing internal organs, etc. There are still disputes. large artificial breasts.
Artificial breasts are the most controversial product in terms of safety. It has been more than 30 years since foreign countries have implanted artificial breasts into the body, and some problems (such as leakage and foreign body reaction) have also occurred; A cautious attitude, but in addition to the cosmetic effect, it still has a strong attraction for those with congenital breast dysplasia or those with defects caused by disease.
Application in drug sustained release system
Prolonging the efficacy of drugs and improving the specificity and safety of drug action is an important topic in drug research. Medical research has proved that in a closed silicone rubber tube, the drug can be slowly released, and a certain drug concentration can be maintained in the body for a long period of time. With the deepening of research, it has been found that silicone rubber has good permeability and Permeability is an ideal drug sustained-release material; drugs take advantage of this property of silicone rubber to effectively control release and slow diffusion through silicone rubber.
Applications in drug sustained release systems include silicone rubber capsules, long-acting contraceptives, matrix drug sustained-release preparations, and skin absorption preparations.
Use as in vitro products
A major feature of silicone rubber film is the selective permeation of oxygen and carbon dioxide. In addition, its moisture permeability is similar to the evaporation of human skin moisture. Therefore, in such applications, it can basically not cause toxicity to the human body, and will not cause allergies and foreign body rejection reactions. After being compounded with nylon and polyester fibers, it can be used as artificial skin very reliably to assist in the treatment of some diseases.
In addition, the addition-type silicone rubber can be used for non-surgical sterilization of female fallopian tubes. This method is ideal; it has become an important method for women undergoing permanent sterilization. Before vulcanization, silicone rubber has a low viscosity and is easy to inject; After vulcanization, the hardness of silicone rubber is moderate, similar to cartilage, has extensibility, has no stimulating effect on surrounding tissues, and will not cause inflammation and foreign body reactions.
Other medical silicone applications
Silicone rubber has other applications. For example, in biomedical engineering, the specific products in this field mainly include medical electronic equipment, medical electrodes, and outer packaging materials for medical bio-implantation sensors.
For example, chemotherapy drug delivery devices for intraperitoneal use. This is an implantable intraperitoneal chemotherapy catheter therapy device made of medical-grade silicone rubber. The device consists of a medicine storage box and a catheter.
Medical electrodes (plates). This product will inevitably come into direct contact with the human body. Therefore, in material selection, medical silicone rubber companies mainly consider softness, comfort, physiological inertness, non-toxicity, no irritation to the skin, and good air permeability. At the same time, the stability of the material is also an important factor because it has to withstand high temperature and high pressure and solvent sterilization. Obviously, under the above conditions, silicone rubber as a substrate has better performance than other materials.
biological sensor. It is widely used in basic research, clinical medicine, food fermentation, environmental protection, etc. Biosensors for implantation usually require a layer of packaging material. Used to isolate the surrounding physiological environment.
the development direction of medical silicone rubber
With the development of biomedical engineering and tissue engineering, the technical and performance requirements of materials are increasing day by day. As far as silicone rubber is concerned, how to make it fully applied to bioengineering and tissue engineering is the main direction of future research work. For example, biosensors are biotechnology that attracts attention today. The miniaturization of biosensors and their adaptability to living organisms will become important research topics related to artificial organs. As the main material of artificial organs, silicone rubber will be used in the future. The development potential is huge.
At present, the development of medical silicone rubber in China is lagging behind. To accelerate the pace of development in the future, we should first establish an industrial production base for medical silicone materials; focus on making breakthroughs in the performance and quality evaluation technology of medical silicone materials implanted in the human body and devices; expand the application field of silicone rubber; Promoting the formation of serialized, high-grade, large-scale and standardized business models for medical silicone rubber materials in my country.