In her oration at Universitas Airlangga (UNAIR) Professorship Inauguration ceremony on Thursday, October 10, 2020, Prof. Dr. Suryani Dyah Astuti, S.Si., M.Si., elaborated the innovation on photonics-based medical instrument development for antimicrobial and biomodulation therapy which are alternative methods to treat biofilm infections in chronic diseases.
On this occasion, Prof. Dyah said, “Photodynamic therapy is a method used to remove harmful cells such as microbes, cancer, and infectious diseases. This innovation with the combination of light, photosensitizer, and oxygen will cause photoinactivation in bacteria which inhibits cell metabolic activity because of damage to cytoplasmic membranes due to peroxidation by reactive oxygen.”
According to Prof. Dyah, photosensitization as a combination is a process of light absorption by photosensitizer molecules which then activates chemical reactions to produce various reactive oxygen species. According to the professor born in Klaten, photosensitization depends on the type and concentration of porphyrin, which acts as a light-absorbing molecule.
“Some bacteria synthesize porphyrin compounds as endogenous photosensitizer molecules that are sensitive to light. The porphyrin spectrum consists of two separate bands, appearing in the near-ultraviolet region and the visible light region, which causes porphyrin rich in colors,” continued Prof Dyah.
“This sensitivity to light is mainly related to the wavelength of light that is exposed. Most of the porphyrin absorbs in the visible light region (400 – 700 nano meters),” said the professor of biophysics.
Furthermore, Prof. Dyah also explained that the presence of a nano-sized photosensitizer (10 -9 m) can increase the percentage of energy absorption, so it is more effective to produce ROS (Reactive Oxygen Species). The research results showed that silver nanoparticles (AgNPs) are effective in increasing the reduction of bacterial biofilms.
“As another example, nano doxycycline is a nano-sized doxycyclin which has more ability to penetrate biofilms and is able to absorb greater light energy due to the wide surface area of light absorption. The use of nano doxycycline on planktonic bacteria and biofilms produces a significant reduction effect,” explained the alumnus of the UNAIR Doctoral program.
Prof. Dyah and the team have developed medical instruments with various products, including the biomodulation dentolaser which can be useful for wound healing and acupuncture. The development started in 2007 with mice testing animals and was developed to become a patented product.