A clean photochemical pathway for reconfiguring the sporopollenin biopolymer into sustainable interfaces for biocompatible cellular applications

• Photochemical treatment effectively reconfigured the surface chemistry of sporopollenin. • Modified sporopollenin exhibited superior hydrophilicity and structural integrity. • Surface oxidation introduced polar functional groups, enhancing biointerface activity. • Treated sporopollenin showed excellent biocompatibility with normal cell lines. • Enhanced adhesion to cancer cells demonstrated improved cellular interaction potential. Sporopollenin material, derived from pollen grains, provides a natural and sustainable platform for applications in advanced materials, controlled drug delivery, and surface engineering due to its exceptional structural robustness and chemical stability. However, its inert surface chemistry limits biological interactions, requiring controlled surface modification to enhance biointerface performance. This study presents a clean photochemical strategy for reconfiguring the surface of sporopollenin biopolymer, thereby improving its biocompatibility and cellular adhesion. Seven sporopollenin microcapsules (SMCs) of varying sizes (12.5–36.3 μm), purified from bee pollen pellets, were exposed to ultraviolet-C (UV-C) irradiation. Characterization by water contact angle, atomic force microscopy (AFM), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) revealed pronounced surface oxidation (O/C ratio increase of up to 78 %) and enrichment in polar functional groups (hydroxyl, carbonyl, and carboxyl), without compromising structural integrity. These modifications induced superhydrophilicity and enhanced cell interaction. Biocompatibility testing using Vero normal cells confirmed SMCs’ safety (GI 50 > 700 µg/mL), while 2,2-diphenyl-1-picrylhydrazyl (DPPH • ) assays indicated higher radical scavenging activity, correlating with surface functionalization. Notably, treated SMCs exhibited up to 52 % higher binding to colorectal cancer cells, Caco-2, as confirmed by scanning electron microscope (SEM) and confocal laser scanning microscopy (CLSM). Overall, this clean photochemical route effectively enhances the interface potential of natural sporopollenin biopolymer for future drug delivery, regenerative medicine, and tissue engineering applications.