Multidentate surfactants for improving stability and biological properties

Nanoparticles must possess specific features tailored to their application area, with consistent characteristics across study batches. Monodispersity and colloidal stability are crucial for metal or metal oxide nanoparticles, requiring surface stabilizers to prevent aggregation. This study addresses the challenge of functionalizing surfactant- coated inorganic nanoparticles for biomedical use, hindered by excess unbound surfactant. Bioconjugation limitations arise from equilibrium between free molecules and those bound to nanoparticle surfaces, impacting in vitro and in vivo biocompatibility. Testing common surfactants like monothiolated polyethylene glycol and amphiphilic polymers, dodecylamine-grafted-poly(isobutylene-alt-maleic-anhydride), revealed insufficient affinity, leading to loss of colloidal stability as excess surfactant is removed. In contrast, newly introduced multidentate surfactants exhibit high avidity, excelling in maintaining stability and suggesting improvements in various nanoparticle applications. The introduction of these polymers addresses biocompatibility issues in the human system where excess stabilizing ligands, post- inorganic nanoparticle synthesis, exceed tolerability, necessitating the removal of excess surfactant despite destabilizing the samples.