Insulin complexation with hydroxypropyl-beta-cyclodextrin: Spectroscopic evaluation of molecular inclusion and use of the complex in gel for healing of pressure ulcers.

The pressure ulcer healing is a complex process and difficult to be achieved. Insulin is known to promote wound healing, and when complexed with cyclodextrin presents improved solubility, stability and biological activity. Complexation of insulin with hydroxypropyl-beta-cyclodextrin (HPßCD) was performed in this work through the coprecipitation method, providing the inclusion complex (HPßCD-I). The spectroscopic techniques used to analyze the complex were H(1) NMR, FT-Raman and FT-IR/ATR. A gel containing the HPßCD-I complex was prepared and a clinical study was conducted in patients with pressure ulcers. The spectroscopic techniques allowed to confirm the complex formation through the inclusion of aromatic amino acids, such as phenylalanine present in the HPßCD cavity. Data obtained from the FT-Raman and FT-IR/ATR techniques, combined with the H(1) NMR results, showed the effectiveness of these techniques in evaluating the inclusion complex of HPßCD with insulin. Clinical studies demonstrated tissue revitalization and a trend (p=0.06) for a significant difference between the healing effect of the control gel and that with HPßCD-I complex. The creation of the gel prepared with insulin and HPßCD-I complex and its use in patients with pressure ulcers appears to be promising in wound healing and its possible use in hospital care.

Morphological and structural changes in lung tissue infected by Paracoccidioides brasiliensis: FTIR photoacoustic spectroscopy and histological analysis.

This study evaluated physical, chemical and morphological changes in lungs of mice infected with Paracoccidioides brasiliensis. The animals were inoculated with 0.1 mL of fungal suspension of the P. brasiliensis 18 isolate and were euthanized 1, 2, 4 and 8 weeks after inoculation. The upper left lobe of the lung was isolated, fixed and processed for paraffin embedding. The sections were stained with H&E for histopathological study, with Gomori-Grocott to locate and identify the fungus, and with TUNEL immunostaining to detect the occurrence of programmed cell death. The lower and middle right lobes were analyzed by Fourier Transform Infrared Photoacoustic Spectrocopy (FTIR-PAS) to investigate physical and chemical features of the infected lungs. The results showed that lungs infected by P. brasiliensis underwent structural changes that varied according to the time period analyzed, and that changes in the absorption bands of different chemical groups resulted from these morphological changes. The results suggest that the combination of FTIR-PAS spectroscopy with morphological evaluation is an effective procedure for the study of paracoccidioidomycosis, one of the most important systemic mycoses that can damage the lung architecture and consequently impair the respiratory function.

Angular dependence of the thermal-lens effect on LiSrAlF6 and LiSrGaF6 single crystals.

We apply thermal-lens (TL) spectrometry to measure the angular dependence of the TL effect on colquiriite single crystals. The experiments were performed with LiSrAlF(6) and LiSrGaF(6) using a two-beam mode-mismatched configuration. The results show that it is possible to minimize the TL effect by selecting the appropriate crystal orientation. Our data also show that the anisotropy of the linear thermal expansion coefficient drives the amplitude of the TL effect, including the inversion from focusing to defocusing as the crystal orientation angle tends to the c-axis direction. The results may be useful for those working to develop a high-power laser using LiSrAlF(6)(:Cr) and LiSrGaF(6)(:Cr) single crystals, allowing for optimization of the designed laser cavity.