A series of hydrogels with intrinsic antifouling properties was prepared via surface-functionalization of poly(2-hydroxyethyl methacrylate) [p(HEMA)]-based hydrogels with the biomembrane-mimicking zwitterionic polymer, poly(2-methacryloyloxyethyl phosphorylcholine) [p(MPC)]. The p(MPC)-modified hydrogels have enhanced surface wettability, high water content retention (61.0%–68.3%), and good transmittance (>90%). Notably, the presence of zwitterionic MPC moieties at the hydrogel surfaces lowered the adsorption of proteins such as lysozyme and bovine serum albumin (BSA) by 73%–74% and 59%–66%, respectively, and reduced bacterial adsorption by approximately 10%–73% relative to the unmodified control. The anti-biofouling properties of the p(MPC)-functionalized hydrogels are largely attributed to the dense hydration layer formed at the hydrogel surfaces by the zwitterionic moieties. Overall, the results demonstrate that biocompatible and antifouling hydrogels based on p(HEMA)-p(MPC) structures have promising potential for application in biomedical materials.

This paper reports the synthesis of three water-soluble halogenated boron-dipyrromethene (BODIPY) photosensitizers (BHTM, BBrTM, and BITM) functionalized with cationic groups to improve biological performance. Introduction of bromine and iodine at the 2,6-positions promoted singlet-oxygen generation through the heavy-atom effect, with quantum yields (ϕ_Δ) of 0.59 for BBrTM and 0.91 for BITM, higher than that (0.11) for the non-halogenated analog BHTM. Incorporation of cationic substituents enhanced hydrophilicity, enabling effective dispersion in aqueous environments and facilitating cellular uptake. Biological evaluations in MCF-7 and HeLa cancer cells revealed minimal dark cytotoxicity (>95% viability at 400 nM) but pronounced phototoxicity under 530 nm light irradiation, confirming efficient photodynamic therapy activity. Confocal laser scanning microscopy further demonstrated favorable fluorescence imaging capability and cytoplasmic localization. Collectively, these findings highlight the potential of water-soluble halogenated BODIPY dyes as dual-function agents for fluorescence-imaging-guided photodynamic therapy.