الفهرس | Only 14 pages are availabe for public view |
Abstract The present study aimed to evaluate the efficiency of two types of nanoparticles against 3rd instar larvae of Cx. pipiens. This study was divided into three main parts: 1. The first part included the synthesis of the nanoparticles and their characterization using transmission electron microscope (TEM). 2. The second part included the evaluation of the efficiency of synthesized nanoparticles against the target vector species. 3. The third part included the investigation of the biochemical impacts of the treatment of mosquito larvae with the synthesized nanoparticles. 1- Synthesis of nanoparticles: A) Silica nanoparticles: Silica nanoparticles were synthesized via a sol-gel method to obtain monodispersed nanoparticles. Transmission electron microscope TEM micrographs showed that the most nanoparticles in the sample were monodispersed with an average particle size below 10 nm. Particles with size of 3.15, 2.83, 3.33, 4.33, 5.92 and 6.06 nm were observed by TEM image analysis software. Simple degree of agglomeration of the particles was noticed in the sample. The properties of the obtained nanoparticles were satisfactorily controlled. B) Hematite nanoparticles: Hematite nanoparticles were synthesized via a hypothermal method to obtain magnetic nanoparticles. TEM micrographs showed that the most nanoparticles in the sample were agglomerated with an average particle size below 10 nm. Particles with size of 5.21, 5.24, 5.42, 5.86, 8.43 and 9.12 nm were observed by TEM image analysis software. Agglomeration of nanoparticles was noticed in the sample. 2- Toxicological Studies: 2.1 Toxicity of nanoparticles against 3rd instar larvae of Cx. pipiens: The obtained results indicated that the toxicity of tested nanoparticles varied according to the concentration used, and the chemical structure. Data revealed that LC50 estimates on the 3rd instar larvae of Cx. pipiens was 0.6662 and 5.7036 ppm for SNPs and HNPs, respectively. While, LC90 estimates were 17.2472 and 648.7061 ppm for same nanoparticles, respectively. Toxicological evaluation revealed that SNPs were the most potent against the 3rd instar larvae of Cx. pipiens. 2.2 Effect of time variation on the larvicidal activity of tested nanoparticles against 3rd instar larvae of Cx. pipiens: In case of SNPs, LT50 estimates corresponding to the tested concentrations (0.025, 0.25, 2.5 and 25 ppm) were 143.23, 39.81, 11.73 and 7.86 hrs. While, LT50 estimates corresponding to the tested concentrations of HNPs (0.025, 0.25, 2.5 and 25 ppm) were 125.49, 76.12, 74.68 and 36.11 hrs. The obtained results at concentration (25 ppm) for the tested nanoparticles indicated that SNPs were the most efficient and the fastest in action. 3- Biochemical studies: 3.1 Determination of total protein and lipid of untreated and treated 3rd instar larvae of Cx. pipiens: Treatment with LC25 and LC50 of HNPs and SNPs reduced the total lipid content with values of 2.49, 3.83, 7.09 and 27.549 %, respectively. Treatment with LC25 and LC50 of HNPs increased total protein content with values of 1.96 and 28.02%, respectively. Treatment with LC25 and LC50 of SNPs obtained induced significant reduction in total protein content of treated larvae with values of 9.71 and 13.37%, respectively. 3.2 Electrophoretic fraction protein patterns (SDS-PAGE) of untreated and treated 3rd instar larvae of Cx. pipiens: The fraction patterns of larval proteins showed different numbers of protein bands according to their molecular weights, they were separated into 31 rows. Electrophoresis revealed differences between the untreated and treated samples. The average bands number of treated samples ranged between 8-13 bands comparing with 8 bands for untreated control. Bands appeared in untreated sample were with molecular weights ranged between (250 and 5) kDa. The total number of bands in sample 2 (treated with LC25 of HNPs) were 8 bands appeared with molecular weights ranged between (140.2 and 11.169) kDa. The total number of bands in sample 3 (treated with LC50 of HNPs) were 12 bands appeared with molecular weights ranged between (250 and 10.765) kDa. The total number of bands in sample 4 (treated with LC25 of SNPs) were 8 bands appeared with molecular weights ranged between (105.2 and 10.765) kDa. The total number of bands in sample 5 (treated with LC50 of SNPs) were 13 bands appeared molecular weights ranged between (250 and 10.765) kDa. |