Ekaterina N. Shuteeva

In the present research, a new type of biomimetic material loaded with chlorophyll derivatives (CpDs) for photodynamic therapy based on poly(3-hydroxybutyrate) (PHB) was fabricated by the electrospinning method. Such matrices showed great potential for the advanced delivery of photodynamic therapeutic reagents to targeted regions and options for prolonged local application. The key morphological characteristics of fibrous materials were investigated. It was found that incorporation of CpDs leads to a change in the average fiber diameter from 3.5 µm to 2.1 µm, increasing porosity from 80% to 90% and accompanied by an over 3-fold increased proportion of open pores. Moreover, the CpD application facilitated fine hydrophilicity tuning, allowing an increase of this parameter up to 10% under different conditions, neutralizing the hydrophobic nature of the matrix polymer and photosensitizer. Moreover, changes in physical properties, supramolecular structure, photosensitizing effect, and singlet oxygen generation were investigated. The data obtained show that the proposed materials are great examples of convenient and reliable carriers for advanced PDT. The results obtained demonstrate high antimicrobial activity in the presence of irradiation as well as noticeable efficacy against carcinoma, both light and dark.

This work is devoted to the electrospinning of biocompatible fibrous matrixes for microbial wound therapy. The problem of treating staphylococcal-infected wounds remains urgent. In this study, we propose a new approach to the use of the chlorophyll (Chl) and poly-3-hydroxybutyrate (PHB) composite system in the treatment of infected wounds. The structure and properties of the electrospun polymer matrix based on PHB modified with various concentrations of Chl was investigated by SEM, confocal microscopy, DSC, EPR. The release rate, fluorescence, and antimicrobial activity of Chl incorporated into PHB were studied. The high efficiency of the developed materials was shown with the participation of laboratory animals.

This work is devoted to the creation of biocompatible fibrous materials with a high antimicrobial effect based on poly-3-hydroxybutyrate (PHB) and chlorophyll (Chl). The data obtained show the possibility of obtaining fibrous materials from PHB and Chl by electrospinning methods. The obtained electrospun matrices were investigated by the SEM, DSC and FTIR methods. Various key properties of the matrices were evaluated, including hydrophilicity and mechanical strength, as well as photodynamic and light-dependent antimicrobial effects against the conditionally pathogenic microorganism Staphylococcus aureus. The results demonstrate a significant improvement in electrospinning properties for a concentration of 0.5% Chl and a reduction in fiber formation defects, as well as an increase in the strength of nonwovens. It was found that the antimicrobial potential of Chl-PHB (with concentrations of Chl of 1.25 and 1.5%) is higher than that of Chl in free form. It was also determined that irradiation increases the inhibitory effect of Chl, both in free form and in the form of a complex with a polymer.