Brownmillerite Calcium Ferrite, a Promising Perovskite-Related Material in the Degradation of a Tight Dye under Ambient Conditions.

Evaluation of effective and low-cost materials as catalysts to combat the threat of pollution is a significant and growing trend. With this aim, we have synthesized calcium ferrite brownmillerite by wet preparation approach as a catalyst for pollution. The structural analysis is established by the X-ray diffraction of Ca2 Fe2 O5 , whereas the tetrahedral and octahedral sites band stretching for ferrite specimen has been deduced using FTIR. The bandgap energy has been estimated by the Tauc relation (2.17 eV). Ca2 Fe2 O5 brownmillerite exhibits a BET surface area of 10 m2 /g and a BJH pore volume of 0.121 cm3 /g with the average particle size of 70 nm. Importantly, the alizarin Red S dye degradation has been studied using the prepared ferrite catalyst, under dark ambient conditions and without the presence of any acidic or basic additives. Degradation is also supported by both FTIR and TOC analysis. Surface properties of brownmillerite Ca2 Fe2 O5 have been characterized using electronic spectroscopy and CO2 temperature programmed desorption (TPD) analysis and revealed that the basic surface of brownmillerite Ca2 Fe2 O5 offers active sites that are suitable for degradation processes. All results show that the preparation of brownmillerite Ca2 Fe2 O5 via the Pechini method is suitable to produce fine surfaces and pores with nanosized particles.

New cyclodextrin-based nanocarriers for drug delivery and phototherapy using an irinotecan metabolite.

SN38 is an active metabolite of irinotecan, which was approved for clinical use in metastatic colorectal cancers. However, poor aqueous solubility and inactivation at pH below 6 are the main limitations of its use. In the current study, we separately conjugated α-, ß- and γ-cyclodextrins to graphene oxide sheets to produce stable, biocompatible nanocarriers for SN38 delivery. The conjugates were coordinated with Fe3O4 in the form of superparamagnetic iron oxide nanoparticles. Then, SN38 was non-covalently conjugated to the developed nano-conjugate in order to overcome its solubility and stability problems and reduce its side effects. The loading efficiency of different formulations was between 13-22%. α-CD-GO-Fe3O4-SN38 and γ-CD-GO-Fe3O4-SN38 significantly enhanced the cytotoxicity of the conjugates compared to the free drug. Besides, combined photothermal/chemotherapy study revealed that all the designed nano-platforms reduced the HT-29 cell line viability synergistically in vitro. However, ß-CD-GO-Fe3O4-SN38 showed the highest synergistic effect compared to other formulations. In conclusion, the results of the study revealed that such combined treatment platforms might find their way as potential therapeutics to fight against cancer.