Temperature Hydrogen Peroxide Gas Plasma Research Articles

Decontamination of N95 masks for re-use employing 7 widely available sterilization methods.

The response to the COVID-19 epidemic is generating severe shortages of personal protective equipment around the world. In particular, the supply of N95 respirator masks has become severely depleted, with supplies having to be rationed and health care workers having to use masks for prolonged periods in many countries. We sought to test the ability of 7 different decontamination methods: autoclave treatment, ethylene oxide gassing (ETO), low temperature hydrogen peroxide gas plasma (LT-HPGP) treatment, vaporous hydrogen peroxide (VHP) exposure, peracetic acid dry fogging (PAF), ultraviolet C irradiation (UVCI) and moist heat (MH) treatment to decontaminate a variety of different N95 masks following experimental contamination with SARS-CoV-2 or vesicular stomatitis virus as a surrogate. In addition, we sought to determine whether masks would tolerate repeated cycles of decontamination while maintaining structural and functional integrity. All methods except for UVCI were effective in total elimination of viable virus from treated masks. We found that all respirator masks tolerated at least one cycle of all treatment modalities without structural or functional deterioration as assessed by fit testing; filtration efficiency testing results were mostly similar except that a single cycle of LT-HPGP was associated with failures in 3 of 6 masks assessed. VHP, PAF, UVCI, and MH were associated with preserved mask integrity to a minimum of 10 cycles by both fit and filtration testing. A similar result was shown with ethylene oxide gassing to the maximum 3 cycles tested. Pleated, layered non-woven fabric N95 masks retained integrity in fit testing for at least 10 cycles of autoclaving but the molded N95 masks failed after 1 cycle; filtration testing however was intact to 5 cycles for all masks. The successful application of autoclaving for layered, pleated masks may be of particular use to institutions globally due to the virtually universal accessibility of autoclaves in health care settings. Given the ability to modify widely available heating cabinets on hospital wards in well-resourced settings, the application of moist heat may allow local processing of N95 masks.

20 Diopter Condensing Lens with Disintegrating Paint; A Potential Problem?

Purpose: To report a potential complication resulting from an inappropriate sterilization method of a 20 Diopter condensing lens intended for use during scleral buckling surgery. Results: Repeated or prolonged sterilization with STERRAD, low temperature hydrogen peroxide gas plasma, can result in chipping of paint on medical equipment. The retention of particulate material in the eye exposes the patient to increased risk of sub-conjunctival granuloma or a misdiagnosis and may result in further surgery. The institutional policy has been revised to prevent recurrence of such event. Conclusion: Disinfection or sterilization of surgical equipment should be performed according to the manufacturer’s recommendations and surgical equipment should be inspected pre-operatively.

Adverse Events with Low Temperature Hydrogen Peroxide Gas Plasma Sterilisation Reported by Certified Sterilisation Service Technicians and Certified Sterilisation Specialists in Japan

Adverse Events with Low Temperature Hydrogen Peroxide Gas Plasma Sterilisation Reported by Certified Sterilisation Service Technicians and Certified Sterilisation Specialists in Japan

Two-stage Reimplantation in Infected Total Knee Arthroplasty Using a Re-sterilized Tibial Polyethylene Insert and Femoral Component

Infection in total knee arthroplasty (TKA) is a challenging complication. We reviewed 20 cases of infected TKAs treated by two-stage reimplantation procedure involving the use of a temporary articulating system composed of autoclaved femoral component, low temperature hydrogen peroxide gas plasma sterilized polyethylene insert, and antibiotic-impregnated bone cement. The knee and functional score of the Knee Society scoring system at the last follow (average, 64.8 months) up was 86.2 points and 78.8 points. The success rate in terms of eradication of infection was 95% (19/20 knees). Use of a temporary articulating system composed of the re-sterilized components with antibiotic-impregnated bone cement was an effective therapy not only for the eradication of the infection but also for the recovery of soft tissue health and knee function.

Sterilization effects on starPEG coated polymer surfaces: characterization and cell viability

Sterilization is frequently an issue for polymeric biomaterials including hydrogels, where autoclaving needs to be discarded, and gamma-irradiation and low temperature hydrogen peroxide gas plasma sterilization are already important alternatives. Coatings based on poly(ethylene glycol) are a well-known strategy to reduce unspecific protein interactions on biomaterial surfaces. Dense, ultrathin coatings of isocyanate terminated star-shaped poly(ethylene glycol) (starPEG) molecules have proven to be resistant to unspecific adsorption of proteins and enable direct biofunctionalization. The effectivity and stability of the starPEG coatings on poly(vinylidene fluoride) (PVDF) were studied after gamma-irradiation (normed dosis 25 kGy) and plasma sterilization (Sterrad 100S). The selected surface properties determined were: surface composition (X-ray photoelectron spectroscopy, XPS), wettability (sessile drop contact angle) and protein adsorption by fluorescence microscopy (Avidin-TexasRed, Bovine Serum Albumin-Rhodamin). Preliminary cell experiments with the cell line L929 were performed prior and after sterilization to investigate the cell repellence of the starPEG coatings as well as cell viability and specific cell adhesion on GRGDS-modified coatings. The starPEG coating undergoes a slight oxidation due to plasma and gamma-sterilization; this represents a minor variation confirmed by XPS and contact angle results. The non-sterilized starPEG and the plasma-sterilized coatings are protein repellent, however the protein adsorption on starPEG coated substrates is much stronger after gamma-sterilization for both avidin and bovine serum albumin. The cell experiments indicate that the starPEG coatings are appliable homogeneously by incubation and are non-cell adherent. Moreover, after both sterilization processes the starPEG coatings remain cell repellent and the GRGDS-modified coatings presented vital cells. Thus we conclude that the plasma sterilization is more convenient for the starPEG coatings and GRGDS-modified starPEG coatings.

Evaluation of the efficacy and usefulness of low temperature hydrogen peroxide gas plasma sterilization system for endoscopies

目的 探讨STERRAD(r)100S过氧化氢等离子低温灭菌系统在内窥镜消毒中的临床应用效果,并与福尔马林熏蒸灭菌法进行比较.方法 2005年1-3月,采用福尔马林熏蒸器械灭菌法完成92台手术104次熏蒸共2 706件内窥镜手术器械灭菌.2005年1-3月采用STER-RAD(r)100S过氧化氢等离子低温灭菌系统完成165台手术180个循环共4 950件内窥镜手术器械灭菌.对比两种方法的器械损耗率、手术感染率,并发放问卷调查医护人员对两种灭菌方法的满意度.结果 STERRAD(r)100S过氧化氢等离子低温灭菌系统在器械损耗率、手术感染率和医护人员满意度指标上均明显优于福尔马林熏蒸灭菌法(P＜0.05).结论 STERRAD(r)100S过氧化氢等离子低温灭菌系统具有环保、安全、低温、快速、节省费用和适用范围广的优点,具有极高的经济价值和社会价值。

Comparison of the effects of gamma radiation and low temperature hydrogen peroxide gas plasma sterilization on the molecular structure, fatigue resistance, and wear behavior of UHMWPE

The effects of gamma radiation and low temperature hydrogen peroxide gas plasma (HPGP) sterilization on structure and cyclic mechanical properties were examined for orthopedic grade ultra-high-molecular-weight polyethylene (UHMWPE) and compared to each other as well as to no sterilization (control). Density was monitored with a density gradient column and was found to be directly influenced by the sterilization method employed: Gamma radiation led to an increase, while plasma did not. Oxidation of the polymer was studied by observing changes in the carbonyl peak with Fourier transform infrared spectrometry and was found to be strongly affected by both gamma radiation and subsequent aging, while plasma sterilization had little effect. Gamma radiation resulted in embrittlement of the polymer and a decreased resistance to fatigue crack propagation. This mechanical degradation was a direct consequence of postradiation oxidation and molecular evolution of the polymer and was not observed in the plasma-sterilized polymer. Both gamma radiation and plasma sterilization led to improved wear performance of the UHMWPE compared to the nonsterile control material.

Assessment of the efficacy of a low temperature hydrogen peroxide gas plasma sterilization system

The STERRAD 100 sterilization system (Johnson & Johnson Medical Ltd) uses low temperature hydrogen peroxide gas plasma for sterilization of heat labile equipment. The efficacy of the machine was tested by contaminating a standard set of instruments with different organisms and using a filtration method to assess recovery of organisms from the wash fluids of instruments post-sterilization. Experiments were performed under clean (the organism only) and dirty (organism mixed with egg protein) conditions. A parallel study conducted using a 3M STERIVAC ethylene oxide sterilizer could not be completed owing to closure of the ethylene oxide plant. For sterilization of instruments with long and narrow lumens, hydrogen peroxide adaptors are necessary. The STERRAD 100 sterilizer can achieve effective sterilization of heat labile instruments with a reduction of 6 log 10 cfu/mL of organisms tested. This method has the advantages over ethylene oxide sterilization of safety, ease of maintenance and no requirement for aeration time.