Antimicrobial surfaces are a promising option for supporting hygiene measures. In addition to many different technologies, research is also ongoing into coatings that are modelled on natural surfaces. In an international project with the National Nanotechnology Laboratory in Costa Rica, the Technical University of Applied Sciences Amberg-Weiden is working on such an aluminum-based nanostructured coating, which is modelled on insect wings and has an antibacterial effect in nature. The aim is to test the effectiveness of these surfaces against bacterial pathogens (Escherichia coli and Staphylococcus aureus) in a standard test procedure, as well as to investigate the resistance of the nanostructures to abrasion and reprocessing. Since the effect of such surfaces depends on the filigree nanostructure, resistance to possible abrasion or damage is a key factor here. Our results show that these coatings exhibit at least significant activity (log 2.2) against the bacteria in the ISO 22196 test setup. Even after repeated wiping of the coatings with sterile water or reprocessing using ultrasound and wipe disinfection, no loss of effectiveness can be detected. Due to the intrinsic antimicrobial effect of the aluminum, the effectiveness of the nanostructured surface is even higher compared to a completely ineffective control surface. If further studies confirm these initial positive results, the coating we investigated could represent another effective alternative in infection control and prevention.

This contribution examines the concept of circular econo-my (CE) within the healthcare sector, introducing the 9R paradigm as a novel framework for the implementation of sustainable strategies. Given the significant CO2 emis-sions from the medical device sector and the heterogene-ous digitalization across the industry, CE offers an avenue to minimize environmental impact while simultaneously enhancing patient care. Leveraging advanced data plat-forms and digital technology can help reduce resource waste and CO2 emissions, while also optimizing patient care by avoiding redundant diagnostics and treatments. The contribution provides a brief introduction for the application of the 9R paradigm in the healthcare sector and highlights the opportunities associated with the im-plementation of CE strategies. It outlines innovative data-driven business models based on CE and digital transfor-mation principles. In conclusion, the strategic application of R-strategies can be described as a multi-layered ap-proach requiring close collaboration among all stakehold-ers to shape a more sustainable and efficient future in healthcare and provide new digital business models.

Introduction

Efficient and effective cleaning and disinfection measures are key factors in preventing infections. To be sufficiently effective, such measures must be carried out conscientiously and according to validated specifications. [1-3] The size of the area to be decontaminated also plays a major role in this case. Due to personnel and time limitations, larger areas can often only be treated superficially and inadequately. One possibility for automated decontamination in such a sce-nario is the dry fog method. Together with the company aquagroup (aquagroup AG, Germany), the Technical Universi-ty of Amberg-Weiden has already been able to demonstrate the general effectiveness of the process in several publica-tions. [4-5]. By adapting the parameters, this technology could also be used to adequately and quickly decontaminate large rooms such as triage tents or large operating theaters. The aim of this work is therefore to further investigate the scalability of the method.

Methods

A painting booth (≈ 138 m3) from the company aquagroup (aquagroup AG, Germany) was used as the test environment in this experimental set up. Contaminated test surfaces were distributed in the room at different distances from the fog outlet. In order to ensure an identical test surface, the contamination was done on disinfected ceramic tile and on plastic surfaces. The decontamination device, consisting of three nozzles and a fan, was placed in the corner of the room and approximately 167 ml of disinfectant (NaOCl) was distributed per nozzle. The decontasmination time was set for 10 minutes.

Results

With one exception (11 CFU), all test sites show residual contamination of less than 10 CFU. The results show a maxi-mum calculated germ reduction of over 5.7 log levels (plastic 5.2 log levels). However, it should be noted that only the bacterial counts of the higher dilution levels can be accounted for and therefore the higher concentrations represent cal-culated values. By recording the room parameters, a change in humidity could also be shown during the course of the experiment. There was a slight increase which is possibly due to the fogging.

Conclusion

Together with our preliminary tests, the general effectiveness of dry fog decontamination in variable settings could again be confirmed. The method can also be scaled to large areas by using several devices in parallel. Due to the struc-ture of the test environment with its relatively large volume and the air permeability provided by the tent-like structure, it is also possible to come to conclusions regarding the effect of the method in realistic environments. Our results sug-gest that the dry fog method can also be used to decontaminate hygienically relevant rooms that are difficult to repro-cess using standard methods due to their size or structure.

Literature

[1] Warren BG, Barrett A, Graves A, King C, Turner NA, Anderson DJ. An Enhanced Strategy for Daily Disinfection in Acute Care Hospital Rooms: A Randomized Clinical Trial. JAMA Netw Open. 2022;5(11):e2242131. doi:10.1001/jamanetworkopen.2022.42131

[2] Robert-Koch-Institut, Aufbereitung von Medizinprodukten: Häufig gestellte Fragen und Antworten, 2020.

[3] Gonzalez EA, Nandy P, Lucas AD, Hitchins VM. Ability of cleaning-disinfecting wipes to remove bacteria from medical device surfaces. Am J Infect Control. 2015 Dec 1;43(12):1331-5. doi: 10.1016/j.ajic.2015.07.024. PMID: 26654235.

[4] Dry-fog disinfection as an alternative method for room decontamination October 2021Current Directions in Biomedical Engineering 7(2):427-429 DOI: 10.1515/cdbme-2021-2108

[5] Dry-fog disinfection as a method for processing vehicles for passenger transport September 2022; Current Directions in Biomedical Engineering 8(2):23-26; DOI: 10.1515/cdbme-2022-1007

Introduction

In numerous medical and pharmaceutical applications very different compositions of mediums are used.. In addition to the correct dosage, a critical thing is to prevent mix-ups, for example 1 M KCL or 1 M NaCl. Using microwave spec-troscopy, all substances are identified and the process can be stopped if an incorrect substance is found. Therefore, au-tomated quality assurance is to be extended by an important step.

Methods

After connecting different reservoirs within one mixing or application process , the different substances run through one single tube set involving the risk of incorrect connection. All components are passed through a tube where a microwave measurement technology is applied. The microwave measuring device is arranged laterally and records the reflection and transmission spectrum in the frequency range between 1 GHz and 6 GHz. From the combination of the spectral components, conclusions are drawn about the respective substance and its concentration using machine learning.

Results

Substances such as amino acid mixtures, glucose and electrolytes of different concentrations can be safely distin-guished from one another. However, currently it is difficult to distinguishn between electrolytes of the same concentra-tion, such as NaCl and KCl. Recently, the overall selectivity could be significantly improved by optimizing the antenna technology.

Conclusion

In principle, the measurement method is able to differentiate between essential groups of substances. The reliable de-tection of Cl- and Na- -ions remains critical. If a suitable contrast based on the ionic mobility or the water structure around the ions is not possible, supplementary or alternative measurement methods are considered.