The self-assembly of supramolecular structures can be controlled or enhanced to improve drug delivery systems through various strategies. These strategies involve manipulating the molecular building blocks, environmental conditions, and external stimuli to achieve the desired properties and functions of the supramolecular structures. Here are some approaches to control or enhance the self-assembly process:1. Molecular design: Designing the molecular building blocks with specific functional groups, shapes, and sizes can influence the self-assembly process. This can be achieved by incorporating hydrogen bonding, van der Waals forces, - stacking, and electrostatic interactions, which can lead to the formation of well-defined supramolecular structures.2. Environmental conditions: The self-assembly process can be influenced by changing the environmental conditions, such as temperature, pH, and solvent composition. For example, a change in temperature can induce a phase transition in the supramolecular structures, while a change in pH can alter the ionization state of the building blocks, affecting their assembly behavior.3. External stimuli: The use of external stimuli, such as light, magnetic fields, and ultrasound, can be employed to control the self-assembly process. For instance, photoresponsive molecules can be incorporated into the building blocks, allowing the supramolecular structures to be controlled by light irradiation. Similarly, magnetic nanoparticles can be used to manipulate the assembly process under an external magnetic field.4. Co-assembly: Combining different types of building blocks can lead to the formation of hybrid supramolecular structures with unique properties. This can be achieved by co-assembling amphiphilic molecules, polymers, peptides, or nanoparticles, which can result in structures with improved stability, responsiveness, and drug loading capacity.5. Template-assisted assembly: The use of templates, such as biological macromolecules or inorganic materials, can guide the self-assembly process and result in the formation of well-defined supramolecular structures. This approach can be used to create drug delivery systems with specific shapes, sizes, and surface properties, which can influence their interaction with biological systems.6. Post-assembly modifications: The properties of the supramolecular structures can be further tuned by performing post-assembly modifications, such as crosslinking, surface functionalization, or encapsulation. These modifications can enhance the stability, biocompatibility, and targeting ability of the drug delivery systems.By employing these strategies, the self-assembly of supramolecular structures can be controlled or enhanced to develop advanced drug delivery systems with improved performance in terms of drug loading, release, targeting, and biocompatibility.