Potential for chromium (VI) bioremediation by the aquatic carnivorous plant Utricularia gibba L. (Lentibulariaceae)

The aquatic carnivorous plant Utricularia gibba has one of the smallest known genomes among flowering plants, and therefore, it is an excellent model organism for physiological and developmental studies. The main aim of our work was to check whether the ubiquitous U. gibba might be useful for the phytoremediation of the highly toxic and mobile hexavalent chromium in waters. Plants were incubated for 1 week in a 50 μM (2.6 mg dm−3) Cr(VI) solution in laboratory conditions. Our results revealed that the plant exhibits a very high accumulation capacity for Cr. The accumulation level was higher than 780 mg kg−1 and a bioconcentration factor >300. On the other hand, the plants showed a low tolerance to the elevated Cr concentration, which was expressed in a significant decrease of the photosystem II activity. However, the most pronounced negative influence of chromate was found on the morphology and activity of the traps. Due to its high accumulation capacity, we suggest that U. gibba may be efficient in the removal of chromate over a short time scale. It can also provide a new molecular resource for studying the mechanisms of Cr(VI) detoxification

Chemical compounds released from specific osteoinductive bioactive materials stimulate human bone marrow mesenchymal stem cell migration

In this work, a poly(L-lactide-co-glycolide) (PLGA)-based composite was enriched with one of the following sol-gel bioactive glasses (SBG) at 50 wt.%: A1-40 mol% $SiO_{2}$, 60 mol% CaO, $CaO/SiO_{2}$ ratio of 1.50; S1-80 mol% $SiO_{2}$, 20 mol% CaO, $CaO/SiO_{2}$ ratio of 0.25; A2-40 mol% $SiO_{2}$, 54 mol% CaO, 6 mol% $P_{2}O_{5}$, $CaO/SiO_{2}$ ratio of 1.35; S2-80 mol% $SiO_{2}$,16 mol% CaO, 4 mol% $P_{2}O_{5}$, $CaO/SiO_{2}$ ratio of 0.20. The composites and PLGA control sheets were then soaked for 24 h in culture media, and the obtained condition media (CM) were used to treat human bone marrow stromal cells (hBMSCs) for 72 h. All CMs from the composites increased ERK 1/2 activity vs. the control PLGA CM. However, expressions of cell migration-related c-Fos, osteopontin, matrix metalloproteinase-2, C-X-C chemokine receptor type 4, vascular endothelial growth factor, and bone morphogenetic protein 2 were significantly increased only in cells treated with the CM from the A1/PLGA composite. This CM also significantly increased the rate of human BMSC migration but did not affect cell metabolic activity. These results indicate important biological markers that are upregulated by products released from the bioactive composites of a specific chemical composition, which may eventually prompt osteoprogenitor cells to colonize the bioactive material and accelerate the process of tissue regeneration

Preparation and characterization of fish skin collagen material modified with β\beta-glucan as potential wound dressing

Collagen possesses unique properties, e.g., biocompatibility, biodegradability, and non-toxicity. However, collagen material degrades too quickly and has low mechanical properties. One of the methods of polymers' modification is mixing them to obtain blends. In this study, the influence of $\beta$-glucan for collagen material was analyzed. The interaction between the functional groups of the polymer was analyzed by ATR-FTIR (attenuated total reflection-fourier transform infrared) spectroscopy. The influence of $\beta$-glucan on mechanical properties was evaluated. The surface properties of materials were assessed using contact angle measurements and the topography of materials was evaluated by AFM (atomic force microscope). The structure of materials was analyzed according to SEM (scanning electron microscopy) pictures. Moreover, the DPPH-free radicals' scavenging ability and biocompatibility against erythrocytes and HaCaT cells were evaluated. Collagen and $\beta$-glucan were bound together by a hydrogen bond $\beta$-glucan addition increased the roughness of the surface of the film and resulted in a more rigid character of the materials. A small addition of $\beta$-glucan to collagen provided a more hydrophilic character. All the materials could swell in in vitro conditions and showed antioxidant activity. Materials do not cause erythrocyte hemolysis. Finely, our cytotoxicity studies indicated that $\beta$-glucan can be safely added at small (10\% or less) quantity to collagen matrix, they sufficiently support cell growth, and the degradation products of such matrices may actually provide some beneficial effects to thesurrounding cells/tissues

The preparation and characterization of chitosan-based hydrogels cross-linked by glyoxal

In this study, hydrogels based on chitosan cross-linked by glyoxal have been investigated for potential medical applications. Hydrogels were loaded with tannic acid at different concentrations. The thermal stability and the polyphenol-releasing rate were determined. For a preliminary assessment of the clinical usefulness of the hydrogels, they were examined for blood compatibility and in the culture of human dental pulp cells (hDPC). The results showed that after immersion in a polyphenol solution, chitosan/glyoxal hydrogels remain nonhemolytic for erythrocytes, and we also did not observe the cytotoxic effect of hydrogels immersed in tannic acid (TA) solutions with different concentration. Tannic acid was successfully released from hydrogels, and its addition improved material thermal stability. Thus, the current findings open the possibility to consider such hydrogels in clinics