The application of biodegradable materials in numerous fields such as biomedical technology has recently showed great interest owing to their excellent properties and environmental friendliness. Unfortunately, biomedical devices fabricated from biodegradable polymers are hit by a major drawback that threatens to endanger the medical field if not appropriately addressed. For instance, such devices suffer from bacterial contamination and infections since they provide the breeding ground for the biofilms both on the surfaces and within the bulks. To this end, there is a need to develop biomedical devices with antibacterial properties to withstand the bacterial growth.
Among the materials used in biomedical applications, polydimethylsiloxane exhibit great properties such as compatibility, ease of fabrication, low cost among others. However, it has poor wetting properties and its hydrophobicity cannot support biological liquids responsible for washing the bacterial elements. On the other hand, the main methods for inducing antibacterial properties to polymers include surface modification and developing biocidal leaching surfaces. The former involves the development of bactericidal or anti-adhesion surfaces while the latter involves releasing cytotoxic compounds that diffuse from the surface material.
In a recent research paper published in Chemical Engineering Journal Istituto Italiano di Tecnologia (Genoa, Italy) researchers: Dr. Evie L. Papadopoulou, Dr. Paola Valentini, Dr. Francesca Mussino, Dr. Pier Paolo Pompa, Dr. Athanassia Athanassiou, Dr. Ilker S. Bayer fabricated a new antibacterial material to withstand bacterial growth. The material was based on polydimethylsiloxane combined with starch bioelastomeric composite containing povidone-iodine with antiseptic properties. The research team demonstrated the complexity of the iodine in starch using the Fourier Transform Infrared Spectrometer and micro Raman measurements. Furthermore, the release of povidone-iodine was investigated for different concentrations and verified by the UV-vis spectrometry. Eventually, an agar test was performed to determine the antibacterial properties of the fabricated material against the E. coli bacteria.
Generally, a robust bioelastomer composite can be formed between the polydimethylsiloxane and starch while povidone-iodine is incorporated to enhance the antibacterial properties of the resulting material. When immersed in water, water gets absorbed by the bioelastomer part thus acting as a solvent for the povidone-iodine. Even though the release of iodine was small, it depended on the concentration of the povidone-iodine. For instance, this could go up to 10% of the total povidone-iodine in the composite.
The authors observed that the fabricated povidone-iodine bioelastomers exhibited excellent antibacterial properties against the E. coli bacteria. This was attributed to the bacteriostatic effect that increased linearly with the increase in the povidone-iodine concentration. In addition, the experimental results showed that after the emersion of povidone-iodine in water, the antibacterial activities could last for more than one month.
The study by Istituto Italiano di Tecnologia scientists has successfully presented the fabrication of antibacterial polydimethylsiloxane-based polymer. Owing to its efficient biocompatibility and capability for use as biomedical material in a situation requiring prolonged antibacterial properties, the fabricated material will be a key contributor to the medical field. It will significantly reduce the contamination and infections of the biomedical tools thus advance surgeries and other medical operations. Also, it can be used as a reference for future work to improve further the materials.
The figure illustrates in an artistic manner the main result of our manuscript. Starch from potatoes and povidone-iodine powder are mixed in a PDMS matrix to make the orange film shown in the left panel. When this film is immersed in water, the film becomes blue-black due to the formation of the starch-iodine complex, where the iodine ions are embedded in the amylose helix of the starch, rendering the material is antibacterial.
Papadopoulou, E.L., Valentini, P., Mussino, F., Pompa, P.P., Athanassiou, A., & Bayer, I.S.(2018). Antibacterial bioelastomers with sustained povidone-iodine release. Chemical Engineering Journal, 347, 19-26.Go To Chemical Engineering Journal