Search

Casein micelle (CM) is a carrier of hydrophobic molecules in breast milk developed by nature. Herein, we evaluated the potential of CM for delivery of hydrophobic pheophorbide a (Pba), a photosensitizer (PS) for in vivophotodynamic therapy (PDT). CM was constructed with casein sodium salt and calcium ions, and Pba was physically loaded into the inner pockets of CM. The resulting CM-Pba was about 220.03 nm in size and showed superior stability without aggregation in aqueous conditions for 4 months. CM-Pba showed fast cellular uptake into SCC7 tumor cells and killed them by photodynamic effects upon laser irradiation. After intravenous injection into SCC7 tumor-bearing mice, CM-Pba showed about 2.0-fold higher tumor accumulation than free Pba. We observed efficient suppression of tumor growth by PDT using CM-Pba after laser irradiation, and there were no significant side effects. The overall results demonstrated that CM could be a potential drug carrier for hydrophobic PS for in vivoPDT.

Current efforts to reduce the density of structural defects such as surface passivation, doping, and modified synthetic protocols have allowed us to grow high-quality perovskite nanocrystals (PNCs). However, the role of the purity of the precursors involved during the PNC synthesis to hinder the emergence of defects has not been widely explored. In this work, we analyzed the use of different crystallization processes of PbX2(X = Cl–or I–) to purify the chemicals and produce highly luminescent and stable CsPbCl3–xBrxand CsPbI3PNCs. The use of a hydrothermal (Hyd) process to improve the quality of the as-prepared PbCl2provides blue-emitting PNCs with efficient ligand surface passivation, a maximum photoluminescence quantum yield (PLQY) of ∼ 88%, and improved photocatalytic activity to oxidize benzyl alcohol, yielding 40%. Then, the hot recrystallization of PbI2prior to Hyd treatment led to the formation of red-emissive PNCs with a PLQY of up to 100%, long-term stability around 4 months under ambient air, and a relative humidity of 50–60%. Thus, CsPbI3light-emitting diodes were fabricated to provide a maximum external quantum efficiency of up to 13.6%. We claim that the improvement of the PbX2crystallinity offers a suitable stoichiometry in the PNC structure, reducing nonradiative carrier traps and so maximizing the radiative recombination dynamics. This contribution gives an insight into how the manipulation of the PbX2precursor is a profitable and potential alternative to synthesize PNCs with improved photophysical features by making use of defect engineering.