EXPANDING BALLOONS: Robust Computational Method for Determining Supramolecular Cage Cavity Morphology Based on the “Inflating Balloon” Metaphor

Supramolecular cages with adjustable internal cavities are widely used as host systems for chemical sensing, catalysis, drug release, and host–guest chemistry. The accurate calculation and visualization of these cavity morphologies are crucial for analyzing and understanding supramolecular cages. Most existing cavity computation tools are suitable for small cavities with few voids, such as those found in natural protein pockets. However, these tools have insufficient accuracy and robustness when applied to larger cavities in supramolecular cages. Drawing inspiration from the concept of deformable container expansion, this paper presents a computational method for determining the morphology of supramolecular cage cavities based on the “inflating balloon” metaphor (CMCC). First, through experimental examination of supramolecular cages, we take the center of mass as the origin of expansion and create probe vertices via subdivision surfaces. Subsequently, we introduce the “probe vertex diffusion algorithm”, which facilitates the generation of the overall cavity morphology by simulating the inflatingballoon process. Through comparative analysis and validation of the experimental results, CMCC is found to have advantages in terms of accuracy and robustness for cavity computation compared with existing primary computational tools for supramolecular cage cavities.