Advances in cell membrane research have enabled the development of innovative biological membrane-based platforms, including therapeutic cells, extracellular vesicles, bacterial membrane vesicles, membrane-coated nanoparticles, and hybrid membrane-based nanomaterials. These platforms leverage diverse membrane receptors for broad biomedical applications. However, several limitations continue to impede their full potential. Biological membrane engineering offers a promising approach to modifying these platforms, thereby enhancing treatment effectiveness. This chapter explores dynamic functionalities of cell membranes and practical characteristics of biological membranes sourced from various cell types, including red blood cells, platelets, white blood cells, stem cells, cancer cells, and bacteria. This chapter further explores the scope and limitations of membrane-based platforms and highlights membrane engineering strategies that enhance cell-cell and cell-biomaterial interactions, provide protection and immune shielding, improve bioactivity through cargo loading, modulate disease microenvironments, and incorporate capturing and tracking functions. It also addresses targeting the blood-brain barrier, improving homing to injured tissues, and strengthening the immune microenvironment. These advancements significantly improve the performance of membrane-based platforms, driving innovations in the treatment of neurodegenerative, infectious, cancerous, gastrointestinal, and other diseases. Finally, the chapter outlines future research directions for engineered membrane-based platforms, focusing on addressing unmet clinical needs and further expanding their biomedical impact.