Positive‐Positive Assembly Behavior in Liquid Metal Hydrogel Colloids

Abstract Negatively charged drug molecules can be efficiently assembled and controlled on the positively charged micro‐nanoparticle (MNP) surfaces by utilizing the principle of electrostatic attraction. However, designing a system that the positively charged protein factors are efficiently assembled onto the positively charged carriers through leveraging homophilic interactions remains a formidable challenge. In solvents, the interplay between the electrostatic repulsion and the van der Waals attraction among the colloidal MNPs leads to the phenomenon of homophilic attraction described in the Derjaguin–Landau–Verwey–Overbeek (DLVO) theory. Is there a colloidal system that can be designed to enable the assembly of positively charged protein factors with the positively charged MNPs? Here, a novel photosensitive positive‐positive assembly of drugs is used as carrier, which is named as InGa 3 @polyvinylpyrrolidone (InGa 3 @PVP). Under the light excitation with the wavelength of 365 nm, this system exhibits homophilic attraction, enabling efficient assembly of the positively charged entities. This discovery offers a refined theoretical model for the drug delivery applications, facilitating the enhanced control and optimization of the positive‐positive assembly.