Fast and cost-effective fabrication of biocompatible polymer nanostructures via sublimation-assisted method for drug delivery applications

The development of efficient and cost-effective methods to fabricate biocompatible polymer nanostructures is essential for advancing controlled drug delivery systems. In this study, we introduce a rapid and versatile sublimation-assisted method, termed ASB-SANS (Auxiliary Solvent-Based Sublimation-Aided NanoStructuring), for directly forming nanostructures of poly-l-lactic acid (PLLA) and poly(lactic-co-glycolic acid) (PLGA) on glass and Si/SiOx substrates. In this approach, chloroform was used as the auxiliary solvent and para-dichlorobenzene (PDCB) as the sublimating agent. Varying the polymer/PDCB ratios systematically from 1 : 50 to 1 : 400 it was possible to control the topology of the resulting nanostructures. Distinct self-assembly behaviours were found between PLLA, which formed elongated nanofibers, and PLGA, which generated highly ordered micro/nanodots arrays. Notably, when loaded with the model drug thionine, ASB-SANS-generated PLGA nanostructures exhibited a significantly suppressed initial burst release (around 60%) compared to the non-nanostructured film, indicating enhanced control over drug release kinetics. This study highlights the potential of ASB-SANS as a powerful method for producing functional polymer nanostructures, offering new opportunities for biomedical applications, particularly in controlled drug delivery systems.