Photodynamic Inactivation (PDI) research has been conducted as a method of photodynamic therapy that combines blue diode laser light (405 nm) with Alfalfa chlorophyll photosensitiser so that it can produce reactive oxygen species that cause biological damage to the target. This study aims to determine the potential of blue diode lasers and the addition of 20% chlorophyll photosensitiser to reduce gram-positive Staphylococcus aureus and gram-negative Pseudomonas aeruginosa which can cause skin infections. The method used is a blue diode laser irradiation of bacteria by the addition of chlorophyll and Total Plate Count (TPC) to determine the decrease in bacterial viability in units of CFU / ml. Test results show that photodynamic inactivation with a blue diode laser and chlorophyll can reduce bacterial viability. Irradiation for 180 seconds at a dose of 1.59 J / cm2 gives the most bacterial death results. The percentage of bacterial death of Staphylococcus aureus was (35.44 ± 1.67)% without photosensitiser, and with photosensitiser the percentage of bacterial deaths increased to (53.59 ± 1.36)%. While the percentage of Pseudomonas aeruginosa bacterial deaths was (20.02 ± 0.76)% without photosensitisers, and with additional photosensitisers it increased to (44.24 ± 1.50)%.
Biofilms are collections of microorganisms that attach to a surface and are covered with extracellular matrices produced by these microorganisms from the environment. A biofilm is an ideal place for plasmid exchange, where plasmids can carry genes that regulate resistance to antibiotics so that biofilms play a role in the spread of bacterial resistance to antibiotics. This allegedly due to changes and rearrangement of cell walls so that antibiotics do not easily penetrate it. An alternative method for reducing biofilm S.aureus is photodynamic inactivation. PDI is a method of inactivation of microorganisms that utilize light, photosensitizers, and Reactive Oxygen Species. This present work aims to determine the potential of blue diode laser as an activator of nano doxycycline to reduce Staphylococcus aureus biofilm. The treatment was divided into six groups, the control group without any treatment, the control group with doxycycline photosensitizer, the control group with nano doxycycline photosensitizer, laser treatment group, laser, and doxycycline treatment group, laser, and nano doxycycline treatment groups. The laser treatment group has a variation of exposure time 30s (4.37 J / cm2), 60s (8.73 J / cm2), 90s (13.09 J / cm2), 120s (17.47 J / cm2), and 150s ( 21.83 J / cm2). Biofilm reduction was measured using an ELISA reader and analyzed using factorial ANOVA. The results showed that 403 nm blue diode laser exposure for 150s with energy density 21.83 J / cm2 could reduce biofilms up to (31.74 ± 1.67)% for the laser treatment group, (65.01 ± 1.67)% for laser and doxycycline treatment groups, (80.25 ± 1.67)% for the laser treatment group and nano doxycycline. So, the exposure of blue diode laser has the potential to activate nano doxycycline to increase the percentage of Staphylococcus aureus biofilm death.
Biofilm is a way used by bacteria to survive from their environmental conditions by forming colony of bacteria. Specific characteristic in biofilm formation is the availability of matrix layer, known as extracellular polymer substance. Treatment using antibiotics may lead bacteria to be to resistant. Other treatments to reduce microbial, like biofilm, can be performed by using photodynamic therapy. Successful of this kind of therapy is induced by penetration of light and photosensitizer into target cells. The sonodynamic therapy offers greater penetrating capability into tissues. This research aimed to use sonodynamic therapy in reducing biofilm. Moreover, it compares also the killing efficacy of photodynamic therapy, sonodynamic therapy, and the combination of both therapeutic schemes (known as sono-photodynamic) to achieve higher microbial killing efficacy. Samples used are Staphylococcus aureus biofilm. Treatments were divided into 4 groups, i.e. group under ultrasound treatment with variation of 5 power levels, group of light treatment with exposure of 75s, group of combined ultrasound-light with variation of ultrasound power levels, and group of combined lightultrasound with variation of ultrasound power levels. Results obtained for each treatment, expressed in % efficacy of log CFU/mL, showed that the treatment of photo-sonodynamic provides greater killing efficacy in comparison to either sonodynamic and sono-photodynamic. The photo-sonodynamic shows also greater efficacy to photodynamic. So combination of light-ultrasound (photo-sonodynamic) can effectively kill microbial biofilm. The combined therapy will provide even better efficacy using exogenous photosensitizer.
Conference Committee Involvement (1)
Third International Seminar on Photonics, Optics, and Its Applications (ISPhOA 2018)
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