Insight into Factors Influencing Wound Healing Using Phosphorylated Cellulose-Filled-Chitosan Nanocomposite Films

Marine polysaccharides are believed to be promising wound-dressing nanomaterials because of their biocompatibility, antibacterial and hemostatic activity, and ability to easily shape into transparent films, hydrogels, and porous foams that can provide a moist micro-environment and adsorb exudates. Current efforts are firmly focused on the preparation of novel polysaccharide-derived nanomaterials functionalized with chemical objects to meet the mechanical and biological requirements of ideal wound healing systems. In this contribution, we investigated the characteristics of six different cellulose-filled chitosan transparent films as potential factors that could help to accelerate wound healing. Both microcrystalline and nano-sized cellulose, as well as native and phosphorylated cellulose, were used as fillers to simultaneously elucidate the roles of size and functionalization. The assessment of their influences on hemostatic properties indicated that the tested nanocomposites shorten clotting times by affecting both the extrinsic and intrinsic pathways of the blood coagulation system. We also showed that all biocomposites have antioxidant capacity. Moreover, the cytotoxicity and genotoxicity of the materials against two cell lines, human BJ fibroblasts and human KERTr keratinocytes, was investigated. The nature of the cellulose used as a filler was found to influence their cytotoxicity at a relatively low level. Potential mechanisms of cytotoxicity were also investigated; only one (phosphorylated microcellulose-filled chitosan films) of the compounds tested produced reactive oxygen species (ROS) to a small extent, and some films reduced the level of ROS, probably due to their antioxidant properties. The transmembrane mitochondrial potential was very slightly lowered. These biocompatible films showed no genotoxicity, and very importantly for wound healing, most of them significantly accelerated migration of both fibroblasts and keratinocytes.

Evaluation of viability indicators of bovine spermatozoa after exposure to silicon dimethylglycerolate using flow cytofluorimetry

Silicon and its dioxide (silica) demonstrate good biological compatibility and a wide range of physical and chemical properties, depending on the production and processing method. In particular, silicon dimethylglycerolate (SDMG) has transmucous and transcutaneous drug conductivity, and, as a hydrogel, may be of interest for the oocytes and embryos cultivation medium structuring and/or media for cryopreservation/thawing of gametes. The aim of this study was to examine the effect of SDMG at concentrations of 0.2 % and 0.02 % on the transmembrane potential of mitochondria and cell viability of bovine spermatozoa. Methods. Sperm subpopulations were assessed for (non)viability indicators (disrupted transmembrane potential of mitochondria, externalization of phosphatidylserine and plasma membrane integrity loss) by flow cytometry with two sets of fluorescent probes. Mitochondrial transmembrane potential was measured using 3,3'-dihexyloxacarbocyanine iodide (DiOC6(3))/ethidium bromide, and externalization of phosphatidylserine – using Annexin V-FITC/propidium iodide pair. The results of this work indicate that SDMG in concentrations of 0.2 % and 0.02 % does not affect the transmembrane mitochondrial potential, externalization of phosphatidylserine or necrotic processes in the population of bovine spermatozoa. The scientific novelty. The data is obtained for the first time on the absence of cytotoxicity of SDMG for male gametes. Together with the shown positive effect of this compound on the morphological parameters and the state of nuclear chromatin of porcine oocytes after intrafollicular vitrification, it should be concluded that silicon-containing glycerohydrogels are of interest as a component of sperm cryopreservation/thawing media.

Cell cycle and transmembrane mitochondrial potential analysis after treatment with chromium(iii), iron(iii), molybdenum(iii) or nickel(ii) and their mixtures

The aim of this study was to examine the effect of chromium(iii), iron(iii), molybdenum(iii) and nickel(ii) and their combinations on the cell cycle and mitochondrial transmembrane potential (MTP) in BALB/3T3 and HepG2 cells.

Oxidised dextrans influence on reactive oxygen species generation by murine peritoneal exudate phagocytic cells

The effects of oxidized dextrans of different molecular weight on reactive oxygen species production and transmembrane mitochondrial potential of macrophages and neutrophils have been studied in vivo and in vitro . Oxidised dextrans demonstrated moderate direct antioxidant ability but induced intracellular oxidative stress through the increase of oxygen radical generation. This effect of the investigated compounds amplifies the cytotoxic and bactericidal potential of phagocytes and can influence isoniazid metabolism, thus increasing its efficiency in therapy of infectious diseases.

Cytotoxicity of PP(Arg)2- and PP(Ala)2(Arg)2-based photodynamic therapy and early stage of apoptosis induction in human breast cancers in vitro.

Mitochondria are cell energetic centers where ATP is produced. They also play a very important role in the PDT as intracellular sites of photosensitizer localization. Photosensitizers gathering in mitochondria (like porphyrin derivatives used in this work) are more effective in tumor cell destruction. Moreover, it was assumed that di-amino acid substituents attached to porphyrin ring will strengthen the effectivity of interaction with membrane receptors of examined cells. MTT assay was performed to investigate the influence of PP(Arg)(2) and PP(Ala)(2)(Arg)(2)-based PDT on breast cancer cell viability for 24 h, 48 h and 120 h after cell irradiation. Then the influence of PP(Ala)(2)(Arg)(2)- and PP(Arg)(2)-mediated PDT on early mitochondrial apoptosis induction via measurements of the transmembrane mitochondrial potential changes was examined. Results showed that lower energy doses and maximal nontoxic photosensitizer doses of PP(Ala)(2)(Arg)(2) and PP(Arg)(2) applied in PDT can imply apoptotic cell death. It was confirmed that modification of the protoporphyrin IX by attaching two alanine substituents raised the efficiency of photodynamic therapy.

Cytotoxicity of PP(Arg)(2)- and Hp(Arg)(2)-mediated photodynamic therapy and early stage of apoptosis induction in prostate carcinoma in vitro.

Porphyrin photosensitizers tend to localize in mitochondria. The depolarization of mitochondrial membrane is one of the early stages of apoptosis and Laser Scanning Fluorescence Microscopy allows to determine changes in transmembrane mitochondrial potential under influence of PDT depending on the kind of photosensitizer (PP(Arg)(2), Hp(Arg)(2)), the energy dose (5, 10, 30 and 50 J/cm(2)) and time periods (24 and 48 hours after irradiation) in the LNCaP (lymphonodal metastasis of prostate carcinoma, the androgen dependent cell line). Cyototoxicity induced by PP(Arg)(2)- and Hp(Arg)(2)-based PDT depending on energy dose and time after irradiation in prostate carcinoma is determined with MTT. Generally, it was shown that lower energy doses induce greater changes in transmembrane mitochondrial potential. Hp(Arg)(2)-based PDT was more effective causing greater mitochondrial membrane depolarization and cell viability decrease in comparison to PP(Arg)(2)-mediated PDT (in the case of maximal nontoxic photosensitizer doses used).