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Funder: DFG (SPP 2196, SCHR 700/38-1), Funder: Royal Society University Research Fellowship, Understanding the kinetics and energetics of metal halide perovskite formation, particularly from the structural point of view at the nanoscale, is important for the advancement of perovskite devices. In particular, insight is needed regarding the mechanisms by which perovskite conversion reactions occur, and their kinetics. Here, we examine the structural evolution of precursor and perovskite phases using in situ synchrotron x-ray scattering. This approach mitigates issues associated with illumination and electron beam-based techniques and allows conclusions to be drawn regarding the kinetics of these reactions. We find that kinetics and grain orientation strongly depend on both the lead halide framework and the nature of the A-cation, with fastest kinetics for MAPbI3, followed by FAPbI3, and slowest for MAPbBr3. Molecular dynamics simulations and density functional theory calculations further reveal that these reactions are diffusion-controlled with a hopping time of 5-400 s, corroborating experimental findings.

Ionic polarization and dielectric function play a fundamental role in the optoelectronic properties of hybrid perovskites, currently one of the most studied materials for next generation photovoltaics. The hybrid nature of the crystal, with molecular dipoles that can reorient within the inorganic lattice, gives rise to a complex dielectric response in the bulk material that has been largely studied and debated. Here, we investigate the nature and the relaxation properties of the dielectric polarization of hybrid perovskites at finite temperature by means of classical molecular dynamics. We provide evidence that a simple ionic model of classical interatomic forces is able to explain qualitatively the temperature and frequency dependence of the dielectric constant providing a picture that is fully consistent with experimental data. The constant dielectric function in the low-temperature phase is controlled by ionic displacements, while the temperature-dependent paraelectric behavior of the tetragonal phase is due to reorientation of dipoles that are responsible for the discontinuity at the orthorhombic-to-tetragonal transition. In the frequency domain, the molecular reorientations give rise to a broad band that is located in the 0.1 THz timescale at room temperature and that shifts down to the GHz timescale when cooling the system toward the tetragonal-to-orthorhombic phase transition. The relation between relaxation time and maximum absorption frequency is also clarified.

Hair loss affects a large number of people worldwide and it has a negative impact on the quality of life. Despite the availability of different drugs for the treatment of hair disorders, therapeutic options are still limited and scarcely effective. An innovative strategy to improve the efficacy of alopecia treatment is presented in this work. Finasteride, the only oral synthetic drug approved by Unites States Federal Drug Administration, was loaded in phospholipid vesicles. In addition, baicalin was co-loaded as an adjuvant. Their effect on hair growth was evaluatedin vitroandin vivo. Liposomes, hyalurosomes, glycerosomes and glycerol-hyalurosomes were manufactured by using a simple method that avoids the use of organic solvents. All the vesicles were small in size (similar to 100 nm), homogeneously dispersed (polydispersity index

Grape extract-loaded fibre-enriched vesicles, nutriosomes, were prepared by combining antioxidant extracts obtained from grape pomaces and a prebiotic, soluble fibre (Nutriose (R) FM06). The nutriosomes were small in size (from similar to 140 to 260 nm), homogeneous (polydispersity index < 0.2) and highly negative (similar to -79 mV). The vesicles were highly stable during 12 months of storage at 25 degrees C. When diluted with warmed (37 degrees C) acidic medium (pH 1.2) of high ionic strength, the vesicles only displayed an increase of the mean diameter and a low release of the extract, which were dependent on Nutriose concentration. The formulations were highly bio-compatible and able to protect intestinal cells (Caco-2) from oxidative stress damage. In vivo results underlined that the composition of mouse microbiota was not affected by the vesicular formulations. Overall results support the potential application of grape nutriosomes as an alternative strategy for the protection of the intestinal tract.

Aim: The moisturizing properties of glycerol, the penetration enhancing capability of propylene glycol and the bioadhesive properties of mucin were combined to improve the carrier capabilities of transfersomes and the efficacy of mangiferin in the treatment of skin lesions. Materials & methods: Mangiferin was incorporated in transfersomes and glycoltransfersomes, which were also modified with mucin. The physico-chemical features were assessed, along with the efficacy against oxidative stress and skin wounds in vitro and in vivo. Results: Glycoltransfersomes promoted the deposition of mangiferin in epidermis and dermis, protected fibroblasts from oxidative stress and stimulated their proliferation. The wound healing and anti-inflammatory efficacy of glycoltransfersomes were confirmed in vivo. Conclusion: Results confirmed the potential of glycoltransfersomes in preventing/treating of skin lesions.

Understanding the kinetics and energetics of metal halide perovskite formation, particularly from the structural point of view at the nanoscale, is important for the advancement of perovskite devices. In particular, insight is needed regarding the mechanisms by which perovskite conversion reactions occur, and their kinetics. Here, we examine the structural evolution of precursor and perovskite phases using in situ synchrotron x-ray scattering. This approach mitigates issues associated with illumination and electron beam-based techniques and allows conclusions to be drawn regarding the kinetics of these reactions. We find that kinetics and grain orientation strongly depend on both the lead halide framework and the nature of the A-cation, with fastest kinetics for MAPbI3, followed by FAPbI3, and slowest for MAPbBr3. Molecular dynamics simulations and density functional theory calculations further reveal that these reactions are diffusion-controlled with a hopping time of 5-400 s, corroborating experimental findings.