The bicomponent spunbonding technology offers high productivity and provides great flexibility in the selection of polymer compositions and fiber configurations. This process was utilized to develop islands-in-the-sea (INS) fabrics consisting of 75% nylon-6 islands and 25% PE sea polymer. The number of islands was varied from 1 (sheath-core) to 108. These webs were hydroentangled at high pressure to cause fracture and fibrillation of the sea polymer and to "release" the islands to form hybrid micro and nanofiber structures. Physical properties as well as aerosol filtration characteristics of these webs were investigated to determine their feasibility for aerosol filtration. The submicron-sized dioctyl phthalate (DOP) particles were used as a challenging aerosol at face velocities in range of 3.3-11.7 cm/s. The filtration efficiency of the webs followed typical behavior for fibrous filtration media in which the most penetration particle size was in range of 0.2-0.3 micron. Surprisingly, the 1 INS web exhibited a higher quality factor compared with other INS webs due to its lower solidity. Also, it was found that corona charging improved the filtration efficiency of 1 INS web 4.3 times compared to discharged webs for 0.2 micron of DOP particles at the face velocity of 5.3 cm/s.