Proflavine

The magnetic properties of La_1-xSr_xMnO₃ (LSMO) nanoparticles within the ferromagnetic region (x∼0.2-0.5) enable their application in two types of cancer treatment: chemotherapy drug delivery and self-controlled hyperthermia.Single-phase La₀.₈₀Sr₀.₂₀MnO₃ nanoparticles were prepared by the sol-gel process followed by mech. processing.Sample characterization was performed by using XRD, TEM, EPR, and DLS techniques.The encapsulation efficiency of proflavine to the nanoparticles was determined via spectrophotometry.The mean size of crystallites of LSMO nanoparticles is 18 nm, and the Curie temperature is 319 K.Bare LSMO particles do not form a colloidally stable aqueous suspension; they exhibit a zeta potential close to zero and provide micro-sized aggregates.Application of sodium citrate for their stabilization leads to a decrease in the size of agglomerates and to a highly neg. zeta potential of -33 mV.The efficiency of proflavine sorption by LSMO nanoparticles increases significantly above the Curie temperature, from 16.1% at 298 K to 26.2% at 333 K.This increase is attributed to the partial disruption of nanoparticle agglomerates in suspension after the LSMO phase loses its ferromagnetic order.In summary, heating LSMO nanoparticles above the Curie temperature increases the degree of drug loading on the nanoparticles.

Simplified quantum chemistry (sQC) methods can routinely compute excited states for very large systems in an "all-atom" fashion. They are viable alternatives to regular multiscale schemes. sQC methods have the advantage of accounting explicitly for all of the environment at a quantum mechanical (QM) level. The treatment of charge-transfer states is now improved by the native implementation of range-separated hybrid (RSH) exchange-correlation functionals into the eXact integral simplified time-dependent density functional theory (XsTD-DFT). After the RSH XsTD-DFT/TDA scheme was benchmarked, XsTD-DFT(/TDA) ultraviolet/visible absorption, circular dichroism (CD), and/or two-photon absorption (2PA) spectra were directly compared to the results of experiments for four challenging and increasingly large systems: eYFP model system, Λ-shaped multimodular D-π-A-π-D'-π-A-π-D chromophore, mixed donor/acceptor ligand Pd(II) double cage [3BF₄@Pd₄D_mA_8-m], and the photoactive yellow protein (PYP). Among the results, this study shows that an "all-atom" approach is unavoidable for reproducing absorption and CD spectra of PYP because one of the main transitions involves a local excitation on a tryptophan.