by Mie Tomzak

DDA industrial grant recipient Sofia Wareham Mathiassen is first author of a study exploring microbial contamination during intended and repeated subcutaneous injections in people with diabetes.

There are many reasons for looking into needle reuse, such as economic costs, needle-related anxiety, environmental impact, dexterity and vision issues, and convenience. Yet it is also associated with patient compliance issues like local pain and bruising, needle clogging, and injection site reactions (ISR). Needle reuse is moreover associated with complications like lipodystrophy, infections, and compromised glycemic control. Given a notable disparity between advice of medical authorities and the widespread practice of needle reuse, the lack of documented infections warrants more studies.

Sofia Wareham Mathiassen is part of one such study. She is the first author of the article ‘Injection site microflora in persons with diabetes: why needle reuse is not associated with increased infections?’ published in Journal of Pathology, Microbiology and Immunology. The article is co-written by Lene Bay, Vera Pinto Glenting, Naireen Fatima, Henrik Bengtsson, and Thomas Bjarnsholt.

"To me, the most surprising finding from this study is how sparse and dispersed the bacterial population is at typical injection sites and how little could be found on the needles and cartridges that had been used sometimes multiple times."

Filling a data gap
The study’s primary aim was to characterise skin microflora at injection sites and establish microbial contamination of used pens injectors and needles. The secondary aim was to evaluate the risk of infections during typical and repeated subcutaneous injections.

“The study originated from a need to understand the microbial contamination of pen injectors and needles during injections. This includes both intended use (single use) and reuse (repeated use of a single-use needle). This research is very useful when designing devices with multi-use potential, to ensure that such design could withstand the microbial challenge it may encounter. In other words, will this design prevent contamination of the bacteria it may contact on the patients' skin? When attempting to assess this, I realized that there was no conclusive data regarding needle contamination. Moreover, I could not find any literature describing the skin microflora at typical injection sites. We then decided to team up with Steno Diabetes Center Copenhagen and Nordjylland to get this data. The doctors and nurses helped me recruit patients for the study and I sampled the patients and provided them with envelopes in which they could return their used needles and pen injectors (cartridges) that we then analysed,” says Sofia Wareham Mathiassen.

A need for sustainable injection devices
“To me, the most surprising finding from this study is how sparse and dispersed the bacterial population is at typical injection sites and how little could be found on the needles and cartridges that had been used sometimes multiple times. Since the first research describing skin microflora, many are under the impression that we are covered in bacteria. While this is certainly true, our skin is an ecosystem of diverse habitats, as varied as niches on earth. Areas typically used for subcutaneous injections (stomach, upper thigh etc.) could be compared to deserts regarding moisture and nutrition for bacteria. This, then, explains why we do not see a correlation between needle reuse and infections in literature,” says Sofia Wareham Mathiassen.

“This research is important in establishing the contamination levels present during subcutaneous injections. This information is useful in addressing compliance issues such as needle reuse, and determining where the risks stem from. Importantly, these findings should be used in the development of simpler, more sustainable, and user-friendly medical devices in the future,” says Sofia Wareham Mathiassen.

"I find it very rewarding to work on projects with the end-user in mind, with an appreciation for how details can make an immense difference in the experience for the patient."

The experience with a DDA Industrial Grant
Sofia’s PhD project is funded with an industrial grant from Danish Diabetes Academy with Novo Nordisk as the co-funding company.

“My project focuses on exploring, assessing and developing antimicrobial technologies for future medical devices. In brief, the aim is to develop a toolbox of materials and technologies that will mitigate microbial contamination during use, thereby allowing for simpler devices with longer in-use times and enhanced user experience. The project originally came from an interest in developing a multi-use needle, so the user would avoid the numerous handling steps from changing the needle after each injection. But antimicrobial materials can be truly useful in a variety of therapeutic and diagnostic devices, and the utility and market for these are only growing,” explains Sofia Wareham Mathiassen.

“My experience with an industrial PhD has been great. First of all, I really enjoy the intersection of academia and industry, where cutting-edge research translates to innovative products that real people can hold in their hands. I find it very rewarding to work on projects with the end-user in mind, with an appreciation for how details can make an immense difference in the experience for the patient. I also really enjoyed working with the two distinct cultures of industry and academia. While navigating both worlds is not always straightforward, I find this first-hand exposure extremely valuable for my perspective, education, and future career,” says Sofia Wareham Mathiassen.

Harvard project and hopes for future research
Sofia was recently a visiting PhD fellow at Wyss Institute for Biologically Inspired Engineering at Harvard University.

“I just got back from Boston a few weeks ago, where I was working on developing an antimicrobial/antifouling and biocompatible sensor coating. To give some context, biosensors work by the binding of an analyte (compound of interest i.e. glucose) to a recognition element (sensor), which then turns this binding into a signal that can be processed. However, one of the main issues with sensors is the binding of compounds that are not of interest (biofouling), which will make your sensor less sensitive. This includes bacteria and other microorganisms. In addition, the interaction with the immune system can be problematic, as your body might recognize the sensor as foreign and attempt to push out or isolate the sensor from the rest of your body, which will compromise the functionality and lifetime of the sensor. My project at Harvard focused on mitigating these occurrences to keep the sensor as sensitive and functional in vivo as possible. We are now in the process of testing and optimizing this coating and getting some great results. I am really excited to see how this will progress”, says Sofia.

“For now, I will focus on tying my research together and hand in my PhD dissertation at the end of the year. The future is yet to be determined, but I'd love to continue in this space of translational research and innovation, creating transformative, sustainable, and safe devices for the patients of tomorrow,” says Sofia Wareham Mathiassen.

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READ THE ARTICLE HERE:
‘Injection site microflora in persons with diabetes: why needle reuse is not associated with increased infections?'
Sofia Wareham Mathiassen, Lene Bay, Vera Pinto Glenting, Naireen Fatima, Henrik Bengtsson, Thomas Bjarnsholt
Journal of Pathology, Microbiology and Immunology, 23 April 2022

CONTACT DETAILS:
Sofia Wareham Mathiassen
Email: lmp449@sund.ku.dk or sfwm@novonordisk.com