Biological and physiochemical studies of electrospun polylactid/polyhydroxyoctanoate PLA/P(3HO) scaffolds for tissue engineering applications.

Polyhydroxyoctanoate, as a biocompatible and biodegradable biopolymer, represents an ideal candidate for biomedical applications. However, physical properties make it unsuitable for electrospinning, currently the most widely used technique for fabrication of fibrous scaffolds. To overcome this, it was blended with polylactic acid and polymer blend fibrous biomaterials were produced by electrospinning. The obtained PLA/PHO fibers were cylindrical, smaller in size, more hydrophilic and had a higher degree of biopolymer crystallinity and more favorable mechanical properties in comparison to the pure PLA sample. Cytotoxicity evaluation with human lung fibroblasts (MRC5 cells) combined with confocal microscopy were used to visualize mouse embryonic fibroblasts (MEF 3T3 cell line) migration and distribution showed that PLA/PHO samples support exceptional cell adhesion and viability, indicating excellent biocompatibility. The obtained results suggest that PLA/PHO fibrous biomaterials can be potentially used as biocompatible, biomimetic scaffolds for tissue engineering applications.

Combination of Multidimensional Instrumental Analysis and the Ames Test for the Toxicological Evaluation of Mineral Oil Aromatic Hydrocarbons.

Mineral oil aromatic hydrocarbons (MOAHs) include mutagenic and carcinogenic substances and are considered a potential health risk. Current methods address the total MOAH content but cannot address the actual toxicological hazard of individual components. This work presents a combined methodology closing those gaps: high-performance liquid chromatography (HPLC) coupled to gas chromatography with flame ionization detection was used to determine the MOAH content. To characterize present substance classes, comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry was applied. Preparative HPLC separated MOAHs into subgroups, which were tested with a miniaturized Ames test evaluating DNA reactivity of isolated fractions. Combining these methods allowed a correlation between present subgroups and DNA reactivity. The developed approach was applied to a mineral oil and distinguished between not DNA-reactive mono- and diaromatics and DNA-reactive tri- and polyaromatics, providing a proof of concept. Hereinafter, it will be applied to diverse sample matrices including mineral oils, food, and food contact materials.

The Effect of Glycol Derivatives on the Properties of Bio-Based Unsaturated Polyesters.

The scope of the present study was to prepare fully bio-based unsaturated polyester resins (UPRs) with comparable properties to the commercial formulations. The focus was set on the determination of the optimal prepolymer formulation using the same set of diacids (itaconic and succinic acid) and different diols (propylene glycol, isosorbide and neopentyl glycol) or its equimolar mixtures, keeping the fixed molar ratio of 1:1:2.1 in all feed compositions. Instead of commonly used styrene, bio-based dimethyl itaconate was used as a reactive diluent (RD). The rheology of the obtained resins was studied in detail. The effect of the used diol on structural (FTIR), thermal (DSC), thermomechanical (DMA), and mechanical (tensile) properties was explained. The properties of UPRs were found to be highly dependent on the diol used in the prepolymer formulation. The UPR with an equimolar ratio of propylene glycol and neopentyl glycol was shown to be the most promising candidate to compete with the commercial petroleum-based resins.

Soft 3D hybrid network for delivery and controlled release of poorly soluble dihydropyrimidinone compound: An insight into the novel system for potential application in leukemia treatment.

Researchers are faced with everyday demands for safer and more efficient therapy for many diseases, especially serious one such as various types of cancer. Numerous anticancer drugs are poorly-water soluble and therefore their encapsulation and controlled release remain quite challenge. In present study, we deepened our research of hydrophilic carrier based on poly(methacrylic acid) and casein (PMAC) by investigating its potential for encapsulation and controlled release of novel poorly water-soluble dihydropyrimidion-azo-pyridon compound (DHPMP). DHPMP is a dye that has been proven to show cytotoxic activity against chronic myeloid leukemia K562 cells. By encapsulating DHPMP into the carrier and delivering it into the intestines, DHPMP absorption could be the fastest and the number of therapeutic doses and side effects can be reduced. Carriers based on PMAC and DHPMP (PMAC-DHPMP) were synthetized and characterized by FTIR, SEM and single compression tests. The swelling behavior of PMAC-DHPMP carriers and cumulative DHPMP release were investigated depending on the amount of crosslinker and encapsulated DHPMP in two media which were simulating pH environments in human stomach and intestines. The prolonged and controlled release of DHPMP was achieved. In vitro cytotoxic activity of PMAC-DHPMP carriers against K562 cells and the cell cycle analysis showed great potential of the carriers for application in leukemia treatment.

Phylogeny and taxonomy of Aspicilia and Megasporaceae.

Phylogenetic analyses based on nuLSU and mtSSU indicate that Megasporaceae is monophyletic. Aspicilia species were distributed among three main well supported groups and one group with low support that included the type species; a division of the family into five genera is proposed. The old names Circinaria and Sagedia are reintroduced for groups not including A. cinerea, the type of Aspicilia. The monotypic Megaspora is closely related to Circinaria, while Lobothallia is the sister group of the other Megasporaceae genera. Aspicilia recedens and A. farinosa are transferred to Lobothallia. Species of the 'Sphaerothallia group' are nested in Circinaria. Aspilidea is not a member of Megasporaceae but seems to be more closely related to Ochrolechiaceae. Aspilidea myrinii is neotypified, and lectotypes are designated for Aspicilia gibbosa, A. leprosescens and Lecanora gibbosula.

Molecular phylogeny and systematics of Polyblastia (Verrucariaceae, Eurotiomycetes) and allied genera.

Phylogenetic relationships of the lichen genus Polyblastia and closely related taxa in the family Verrucariaceae (Verrucariales, Chaetothyriomycetidae) were studied. A total of 130 sets of sequences (nuLSU rDNA, nuITS rDNA and RPB1 region A-D), including 129 newly generated sequences, were analysed. Phylogenetic relationships were inferred using a Bayesian approach based on two datasets. A first analysis of a larger, two-locus dataset (nuLSU and RPB1) for 128 members of the Verrucariaceae, confirmed the polyphyly of Polyblastia, Thelidium, Staurothele, and Verrucaria, as currently construed. The second analysis focused on 56 Polyblastia and allied taxa, but using an additional locus (nuITS rDNA) and two closely related outgroup taxa. The latter analysis revealed strongly supported groups, such as Polyblastia s. str., the Thelidium group (a mixture of Polyblastia, Thelidium, Staurothele and Verrucaria species). The genus Sporodictyon, which is here accepted, also accommodates Sporodictyon terrestre comb. nov. Morphological features traditionally used for characterizing Polyblastia, Thelidium, Staurothele and Verrucaria, such as spore septation and colour, occurrence of hymenial photobiont, involucrellum structure, and substrate preference, were found to be only partially consistent within the strongly supported clades, and thus are not always reliable features for characterizing natural groups.