In addition, more cells differentiated on aligned nanofibers than aligned microfibers. Mascaras designed to lengthen or curl the eyelashes often contain nylon or rayon microfibers. Alternative types of insulation are being invented including&colon; synthetic microfibers and polyester-based insulation. These include microfibers from clothing, microbeads, and plastic pellets (also known as nurdles). It consists of carbon microfibers manufactured into flat sheets. Another major polluter that not many people think could even be possible is synthetic microfibers. Remaining microfibers that have not undergone biodegradation can cause harm to marine life. The microfibers also promoted myelination during peripheral nerve repair. Microplastics and microfibers were also found in snow samples. Microfibers are tiny threads that are shed from fabric. Microfibers in textiles refer to sub-denier fiber (such as polyester drawn to 0.5 denier). Microfibers account for 85% of man-made debris found on shorelines worldwide.