"It was an inspiring event, full of amazing women from the STEM field. I’m happy I could share my work and exchange experiences with participants from all over the world!" – reports Rukudzo.
Rukudzo began her research on new biomaterials with bactericidal properties under the supervision of Ph.D., D.Sc. Anna Sobczyk-Guzenda from the Institute of Materials Engineering. The initial phase of this research was presented in the article Polysiloxane-Based Composite Coatings with Bactericidal Additives, where Rukudzo Chihota was the lead author, collaborating with Heronim Szymanowski, Ph.D., D.Sc., Witold Kaczorowski, Ph.D. D.Sc., Jacek Grabarczyk, Ph.D., D.Sc., Aleksandra Jastrzębska, Ph.D. (Eng.), Professor Piotr Niedzielski, Ph.D., D.Sc., Katrina Los, Ph.D. (Eng.), and Anna Sobczyk-Guzenda, Ph.D., D.Sc.
Regarding her research, Rukudzo Chihota writes:
Advancements in medical device technology in recent years have not only improved patient comfort but also significantly increased average life expectancy. However, infections associated with medical devices remain a serious issue, often leading to complications such as tissue damage or organ failure. Although antibiotics are frequently used to combat these infections, the growing threat of antibiotic resistance poses an increasing risk. To effectively address this challenge, the development of biomaterials with bactericidal properties is essential.
In this work, the effects of natural and synthetic additives in various concentrations were studied within a polysiloxane matrix to develop composites with bactericidal properties. Natural additives such as black cumin, cloves, and turmeric, which are intensively studied for their antimicrobial properties, were compared with silver, a known antiseptic, and graphene, which shows potential bactericidal properties, although not yet fully confirmed.
The first stage of the research involved producing polysiloxane composites containing different concentrations of these powders in the form of solid samples. A series of tests were then conducted to assess not only their bactericidal properties but also their physicochemical characteristics, such as chemical structure, surface wettability, roughness, hardness, and surface morphology.
Based on the results, the most promising composite formulations were selected and used to produce coatings on polished substrates made of 316L medical steel and glass. The adhesion of these coatings to the substrates used was determined using an innovative method of peeling off coatings using a multifunctional device from Brüker.
The results showed that all obtained materials exhibited high bactericidal properties, with the strongest effects observed in samples containing high concentrations of turmeric, black cumin, cloves, and silver in the polymer matrix. The studies confirmed that bacterial survival was lower on all composite surfaces compared to pure polysiloxane.
It was observed that cloves and black cumin had a negative impact on the cross-linking of the polymer, which opens a direction for further research. The additives also significantly influenced the mechanical properties of the polysiloxane matrix: graphene increased the hardness of the composites, while turmeric significantly improved the adhesion of coatings to very smooth surfaces, highlighting its strong potential for enhancing the durability of coatings used in medical devices.
The research conducted may significantly contribute to improving infection control in healthcare facilities and the development of innovative, drug-free medical technologies. Moreover, the bactericidal nature and durability of the composites, in both solid form and as coatings on various surfaces, are material properties highly valued and sought after by many manufacturers of plastics, silicones, paints, and other utility materials. This work demonstrated that by using human-safe additives, such as turmeric, in synthetic polymer matrices, it is possible not only to enhance their antiseptic properties but also to significantly improve the mechanical properties of the resulting composites.