Sterilization principle of ethylene oxide (EO)
Ethylene oxide can kill various microorganisms, including bacterial propagules, spores, viruses and fungal spores, and is a broad-spectrum sterilant. It is generally believed that it is due to its ability to undergo non-specific alkylation with microbial proteins, DNA and RNA. EO in aqueous solution can undergo alkylation with free carboxyl groups (COOH groups (2NH2), sulfhydryl groups (2SH) and hydroxyl groups (2OH) on proteins, replacing unstable hydrogen atoms to form compounds with hydroxyethyl groups (CH2CH2OH). The groups on proteins are alkylated, causing proteins to lose the reactive groups needed in basic metabolism, hindering the normal chemical reactions and metabolism of bacterial proteins, and thus leading to the death of microorganisms.
So far, all data show that the bactericidal effect of EO is irreversible, that is, EO is a sterilant (sterileag ent) rather than disinfectant, and according to various clinical and scientific research results, EO is a chemical sterilant with the best sterilization effect among all chemical disinfectants or sterilants. Ethylene oxide can inhibit the activity of some microbial enzymes, including phosphatase, peptidase, cholinesterase and cholinesterase. Ethylene oxide also reacts with DNA and RNA to alkylate and inactivate microorganisms.
Scope of application of EO sterilization
EO has a wide range of uses in medical devices and medical products. Commonly used medical products for EO sterilization include (1) disposable medical protective masks, disposable sterile syringes, disposable blood products, disposable plasma separation cups, disposable leukocyte removal filters, disposable plasma bags, disposable blood collection devices, disposable sterile urinary catheters, disposable blood containers, disposable protective clothing, soft tissue expanders, medical surgical masks, medical absorbent cotton, implantable drug delivery devices, medical infusion sets, Medical blood transfusion devices, etc. (2) Equipment and instruments include: ① Rigid and flexible endoscopes: arthroscopes, bronchoscopes, cystoscopes, gastroscopes, colonoscopes, mediastinoscopes, ophthalmoscopes, otoscopes, pharyngoscopes, rectoscopes, prostatectomy devices, thoracoscopes, and urethroscopes. ② Medical equipment: anesthesia equipment, artificial kidneys, diathermy equipment, wires, meters, heart-lung machines, respiratory and therapeutic equipment, and hemodialysis. ③ Instruments: electric drills, electric burners, electric knife pens, dental drills, microsurgical instruments, nerve stimulators, compression devices, Dynamometers, surgical instruments, bone drills, needles, artificial joints. ④ Rubber products: infusion sets, catheters, dilators, drainage tubes, endotracheal tubes, surgical gloves, sheets. ⑤ Plastic products: tracheal tubes, dilators, endotracheal tube gloves, pacemakers, heart valves, sprayers, culture dishes, syringes. ⑥ Other books, toys, linear bougies, bougies, thermometers, sutures. Therefore, ethylene oxide has been, is and will continue to be a major low-temperature sterilization method.
