DEVELOPMENT OF NANOEMULSION AND ITS CHARACTERIZATION FOR ANTI BIOFILM AND LARVICIDAL ACTIVITY

Dengue is a mosquito borne viral disease and the main root cause vector is Aedes aegypti. Hence in this work a rapid measure was taken to eradicate the vector using nanoemulsion. Plant essential oil based nanoemulsions was formulated by ultrasonic emulsification method.  In the current study, nanoemulsion (O/W) was developed using oil extracted from the leaves of a Tulsi, Neem and Nochi. The emulsions were prepared in different ratios of oil and surfactant (Tween 80) and evaluated for their mechanical and thermal stability. After the confirmation of stable nanoemulsion formation, it was evaluated for its antibiofilm activity. Results revealed that the formulated mixed oil nanoemulsion exhibited enhanced antibiofilm activity against isolated microorganisms from contaminated wall samples. Further the biofilm forming capability of bacterial culture was indirectly assessed by staining with 1% crystal violet and measured absorbance using ethanol as a destaining solution. The mean biofilm production of S3 bacterial isolates significantly greater than that observed for S1 & S2. In addition, antibiofilm activity of the emulsion NE3 was higher against bacterial culture S3. Different concentration of mixed oil nanoemulsiom (NE3) treated group was subjected to evaluate the larvicidal activity against Aedes aegypti between 1 to 12 hours respectively. It was observed that an increase in the nanoemulsion concentration (NE3) to 25 ppm and 50 ppm resulted in complete loss of larval viability in 5 hr and 6 hr respectively. There is no significant difference in larval viability after 6 hr and 12 hr in all the treatment groups. Hence the above findings suggest the applicative potential of mixed nanoemulsion formulation for various applications including mosquito larval control and antibiofilm activity.