A supramolecular method to control protein assembly using a biogenic polyamine

We report a method to modulate the formation and stability of nano- and micro-assemblies of bovine serum albumin (BSA) formed with CB[7] using the treatment of a biogenic polyamine such as spermine (SPM). Our findings show that SPM impacts the size and surface charge of BSA-CB[7] assemblies, effectively reducing the size of nanoscale particles and making their surface charges more positive. Conversely, for larger particles spanning more than a few micrometres in diameter, SPM treatment is less effective in reducing their size. This ineffectiveness is attributed to the interaction between the external surface of CB[7] and BSA, which remains relatively unaffected by SPM. Over time, with an excess of CB[7], this interaction becomes more pronounced, resulting in aggregation of large particles and subsequent sedimentation. Since SPM is a biogenic polyamine found at elevated levels in cancerous tissues, this result may offer a strategic direction for designing supramolecular systems to control protein assemblies in oncological environments, highlighting the significant potential of supramolecular chemistry in biomedical applications.