AUTHOR=Shershnev Ilya , Solovieva Anna , Kopylov Alexander , Cherkasova Anastasiya , Kaplin Vladislav , Rachev Sergey , Kuryanova Anastasiya , Aksenova Nadezhda , Timofeeva Victoriya , Akovantseva Anastasiya , Zarkhina Tatyana , Shantarovich Viktor , Bekeshev Valentin , Bikmulina Polina , Huang Ru-Lin , Li Qingfeng , Timashev Peter TITLE=Photosensitizing systems based on alginate aerogels and methylene blue for controlled release of dye for antimicrobial photodynamic therapy JOURNAL=Frontiers in Chemistry VOLUME=Volume 13 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2025.1702876 DOI=10.3389/fchem.2025.1702876 ISSN=2296-2646 ABSTRACT=Photosensitizing systems based on methylene blue (MB)-loaded calcium alginate (CaA) and alginic acid (AA) aerogels were developed for photodynamic therapy of difficult-to-heal wounds. Hybrid aerogels incorporating polyvinylpyrrolidone (PVP, 2.5–40 wt%) into CaA and AA matrices were also made. The MB release kinetics in a phosphate buffer were found to depend on the aerogel type (AA or CaA). The incorporation of PVP increased the MB release rate by 1.5–2 times. The singlet oxygen (1O2) generation efficiency of MB embedded in the aerogels was influenced by their porosity and chemical composition. The activity of MB in the photogeneration of 1O2 increased by up to four times in the PVP-containing aerogels. Furthermore, the photoactivity of MB in the hybrid aerogel matrices significantly exceeded that in the single-component alginate aerogels.