Theoretical study on the possible use of SiC microparticles as photothermal agents for the heating of bacteria

Abstract

Gold nanoparticles exhibiting surface plasmon resonances have been considered as photothermal agents for the selective destruction of bacteria by visible to near-infrared radiation. Here, we consider theoretically the possible complementary use of sub-micron silicon carbide (SiC) particles as photothermal agents for the heating of bacteria by pulsed mid-infrared (MIR) radiation. A SiC microparticle can exhibit surface phonon resonances in the MIR. Similar to the effect of surface plasmon resonances in gold nanoparticles, this could lead to enhanced absorption at the resonant wavelength and strong heating of the microparticle locally. If the heating is sufficient, this might lead to damage of bacterial cells adjacent to SiC particles. We estimate the heating of sub-micron SiC particles in a water medium under various pulse lengths of radiation at wavelength 10.6 μm. Noting that SiC is being investigated as a biocompatible material that could be functionalized for biomedical applications, and that an appropriately roughened SiC surface could be expected to exhibit similar surface phonon resonances, we speculate that enhanced heating under MIR radiation may be useful for in vitro sterilization of such surfaces.

Review of titanium surface modification techniques and coatings for antibacterial applications

“…mutans [66], S. aureus [67] and A. acti nomycetemcomitans. [45,46,68] Bacterial counts on ion-implanted surfaces were reduced by 55-80% compared to pure titanium. [53] However, it is unclear how anodic oxidation without ionimplantation influences bacterial adhesion to titanium [68][69][70].…”

“…Controversially, a debate still persists over the possible inactivation of silver mediated antibacterial activity in physiological fluids and over the low biocompatibility index of silver determined by the low threshold concentration for cytotoxic effects, especially when in the form of nanoparticles. [31,46]…”

Oxidative power of aqueous non-irradiated TiO 2 -H 2 O 2 suspensions: Methylene blue degradation and the role of reactive oxygen species

“…Several groups have proposed surface modifications which would allow the destruction of biofilms a posteriori by thermal inactivation. 111,112 A different approach is the development of biomaterials which are used to destroy or support the destruction of existing biofilms during infection therapy. A hydrogel enriched with TiO2 microparticles has been proposed to improve the mechanical decontamination in periimplantitis treatment.…”

The Effect of the Shape and Size of Gold Seeds Irradiated with Ultrasound on the Bio-Heat Transfer in Tissue

“…Thus generally a large number of nanoparticles would be needed to effectively heat an entire cell, for example, the size of which can be of the order of microns to tens of microns. Recent studies have suggested the complementary use of sub-micron silicon carbide (SiC) particles as photothermal agents for the heating of bacteria by pulsed mid-infrared (MIR) radiation [37]. If a material is a good conductor of heat then the heat will move quickly.…”