Virus-like particles (VLPs) are self-assembled structures that mimic the structure of viruses but do not contain any viral genetic material, making them non-infectious. VLPs are often used in research as a tool to study the structure and biology of viruses, as well as potential vaccine candidates. They can be produced through recombinant DNA technology using a variety of expression systems, such as bacteria, yeast, or insect cells. VLPs have also shown promise as delivery vehicles for drugs and vaccines, due to their ability to stimulate immune responses without causing disease. Overall, VLPs are a versatile and increasingly important tool in virology research and vaccine development.