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Recently, lichens came once more into the scientific spotlight due to their unique relations with prokaryotes. Several temperate region lichen species have been thoroughly explored in this regard yet, the information on Antarctic lichens and their associated bacteriobiomes is somewhat lacking. In this paper, we assessed the phylogenetic structure of the whole and active fractions of bacterial communities housed by Antarctic lichens growing in different environmental conditions by targeted 16S rRNA gene amplicon sequencing. Bacterial communities associated with lichens procured from a nitrogen enriched site were very distinct from the communities isolated from lichens of a nitrogen depleted site. The former were characterized by substantial contributions of Bacteroidetes phylum members and the elusive Armatimonadetes. At the nutrient-poor site the lichen-associated bacteriobiome structure was unique for each lichen species, with chlorolichens being occupied largely by Proteobacteria. Lichen species with a pronounced discrepancy in diversity between the whole and active fractions of their bacterial communities had the widest ecological amplitude, hinting that the nonactive part of the community is a reservoir of latent stress coping mechanisms. This is the first investigation to make use of targeted metatranscriptomics to infer the bacterial biodiversity in Antarctic lichens.

Lichens are presently regarded as stable biotopes, small ecosystems providing a safe haven for the development of a diverse and numerous microbiome. In this study, we conducted a functional diversity assessment of the microbial community residing on the surface and within the thalli of Leptogium puberulum, a eurytopic cyanolichen endemic to Antarctica, employing the widely used Biolog EcoPlates which test the catabolism of 31 carbon compounds in a colorimetric respiration assay. Lichen thalli occupying moraine ridges of differing age within a proglacial chronosequence, as well as those growing in sites of contrasting nutrient concentrations, were procured from the diverse landscape of the western shore of Admiralty Bay in Maritime Antarctica. The L. puberulum bacterial community catabolized photobiont- (glucose-containing carbohydrates) and mycobiont-specific carbon compounds (d-Mannitol). The bacteria also had the ability to process degradation products of lichen thalli components (d-cellobiose and N-acetyl-d-glucosamine). Lichen thalli growth site characteristics had an impact on metabolic diversity and respiration intensity of the bacterial communities. While high nutrient contents in lichen specimens from “young” proglacial locations and in those from nitrogen enriched sites stimulated bacterial catabolic activity, in old proglacial locations and in nutrient-lacking sites, a metabolic activity restriction was apparent, presumably due to lichen-specific microbial control mechanisms.

Strains P8930T and 478 were isolated from Antarctic glaciers located on James Ross Island and King George Island, respectively. They comprised Gram-stain-negative short rod-shaped cells forming pink pigmented colonies and exhibited identical 16S rRNA gene sequences and highly similar MALDI TOF mass spectra, and hence were assigned as representatives of the same species. Phylogenetic analysis based on 16S rRNA gene sequences assigned both isolates to the genus Pedobacter and showed Pedobacter frigidisoli and Pedobacter terrae to be their closest phylogenetic neighbours, with 97.4 and 97.2 % 16S rRNA gene sequence similarities, respectively. These low similarity values were below the threshold similarity value of 98.7%, confirming the delineation of a new bacterial species. Further genomic characterization included whole-genome sequencing accompanied by average nucleotide identity (ANI) and digital DNA–DNA hybridization calculations, and characterization of the genome features. The ANI values between P8930T and P. frigidisoli RP-3-11T and P. terrae DSM 17933T were 79.7 and 77.6 %, respectively, and the value between P. frigidisoli RP-3-11T and P. terrae DSM 17933T was 77.7 %, clearly demonstrating the phylogenetic distance and the novelty of strain P8930T. Further characterization included analysis of cellular fatty acids, quinones and polar lipids, and comprehensive biotyping. All the obtained results proved the separation of strains P8930T and 478 from the other validly named Pedobacter species, and confirmed that they represent a new species for which the name Pedobacter fastidiosus sp. nov. is proposed. The type strain is P8930T (=CCM 8938T=LMG 32098T).

Colobanthus quitensis (Kunth) Bartl. and Deschampsia antarctica Desv. are the only Magnoliophyta to naturally colonize the Antarctic region. The reason for their sole presence in Antarctica is still debated as there is no definitive consensus on how only two unrelated flowering plants managed to establish breeding populations in this part of the world. In this study, we have explored and compared the rhizosphere and root-endosphere dwelling microbial community of C. quitensis and D. antarctica specimens sampled in maritime Antarctica from sites displaying contrasting edaphic characteristics. Bacterial phylogenetic diversity (high-throughput 16S rRNA gene fragment targeted sequencing) and microbial metabolic activity (Biolog EcoPlates) with a geochemical soil background were assessed. Gathered data showed that the microbiome of C. quitensis root system was mostly site-dependent, displaying different characteristics in each of the examined locations. This plant tolerated an active bacterial community only in severe conditions (salt stress and nutrient deprivation), while in other more favorable circumstances, it restricted microbial activity, with a possibility of microbivory-based nutrient acquisition. The microbial communities of D. antarctica showed a high degree of similarity between samples within a particular rhizocompartment. The grass’ endosphere was significantly enriched in plant beneficial taxa of the family Rhizobiaceae, which displayed obligatory endophyte characteristics, suggesting that at least part of this community is transmitted vertically. Ultimately, the ecological success of C. quitensis and D. antarctica in Antarctica might be largely attributed to their associations and management of root-associated microbiota.

Polyhydroxyalkanoates (PHAs), the intracellular polymers produced by various microorganisms as carbon and energy storage, are of great technological potential as biodegradable versions of common plastics. PHA-producing microbes are therefore in great demand and a plethora of different environments, especially extreme habitats, have been probed for the presence of PHA-accumulators. However, the polar region has been neglected in this regard, probably due to the low accessibility of the sampling material and unusual cultivation regime. Here, we present the results of a screening procedure involving 200 bacterial strains isolated from 25 habitats of both polar regions. Agar-based tests, microscopy, and genetic methods were conducted to elucidate the biodiversity and potential of polar-region PHA-accumulators. Microscopic observation of Nile Red stained cells proved to be the most reliable screening method as it allowed to confirm the characteristic bright orange glow of the Nile Red&ndash, PHA complex as well as the typical morphology of the PHA inclusions. Psychrophilic PHA-producers belonged mostly to the Comamonadaceae family (Betaproteobacteria) although actinobacterial PHA synthesizers of the families, Microbacteriaceae and Micrococcaceae also featured prominently. Glacial and postglacial habitats as well as developed polar region soils, were evaluated as promising for PHA-producer bioprospection. This study highlights the importance of psychrophiles as biodiverse and potent polyhydroxyalkanoate sources for scientific and application-aimed research.

The potential use of TiO2 nanotube layers as a self-sterilizing and self-cleaning material for environmental application is presented. Antimicrobial, antibiofilm and photocatalytic performance of anodic TiO2 nanotube layers under UV irradiation was investigated on titanium mesh and on Ti sputtered on silicon substrates. The nanotubes were prepared in fluoride containing ethylene glycol-based electrolyte to obtain ~ 4 µm thick nanotube layers, which were subsequently annealed at 450 °C. Structural and morphological properties of prepared TiO2 layers were characterized using X-ray diffraction, scanning electron microscopy and atomic force microscopy. In addition, their surface wettability, before and after UV irradiation, was investigated. Their photoactivity was compared to TiO2 sol–gel films of similar thickness. The highest efficiency in photocatalytic degradation of organic dye and removal of free-floating bacteria of Gram-positive Staphylococcus epidermidis was observed for TiO2 nanotube layers on titanium mesh. The highest antibiofilm performance in impairments of biofilms was reached using the TiO2 nanotubes on silicon. The obtained results on silicon substrate are promising for the development of medical devices covered by TiO2 nanotubes that would decrease the risk of infection. On the other hand, the mesh substrate covered by TiO2 nanotubes could find environmental applications such as filters in flowing photocatalytic reactors.

Bacterial cellulose (BC), produced by Komagataeibacter xylinus, has numerous applications to medicine and industry. A major limitation of BC use is relatively low production rates and high culturing media costs. By supplementing culture media with 1% vegetable oil, we achieved BC yield exceeding 500% over the yield obtained in standard media. BC properties were similar to cellulose cultured in standard methods with regard to cytotoxicity but displayed significantly higher water swelling capacity and mechanical strength. As we demonstrated herein, this significantly increased BC yield is the result of microscopic and macroscopic physiochemical processes reflecting a complex interaction between K. xylinus biophysiology, chemical processes of BC synthesis, and physiochemical forces between BC membranes, oil and culturing vessel walls. Our findings have significant translational implications to biomedical and clinical settings and can be transformative for the cellulose biopolymer industry.

Corn processing generates thousands of tons of cob husks, which still contains many valuable elements. To make the most of these wastes, they are applied as substrates for biotransformation’s procedures. This approach allowed converting or releasing, the elements deposited in the plant material and obtaining valuable products. Thus bioconversion of corn cob husks (CCH) using a fungus of the Fusarium culmorum genus resulted in obtaining silica nanoparticles of defined size and morphology. SEM analysis excluded their presence on the surface of the substrate. FTIR confirmed the presence of siloxane bonds and O-Si-O bonds in post-biotransformation fluid. Using the Heteropoly Blue Method, it was checked that the highest concentration of silica during 16-day biotransformation falls on the 7th day of the process, in which both the substrate sterilization and the process of the biocatalyst starvation were of key importance. Using the STEM and EDX analysis, it was proved that the obtained nanoparticles with a spherical form are structured and their dimensions are ~40 and ~70 nm. ICP-OES proved that the overall process efficiency was 47%. Such nanoparticles can be successfully used in the medical industry.

Adelie penguins (Pygoscelis adeliae) are the most numerous flightless bird group breeding in coastal areas of Maritime and Continental Antarctica. Their activity leaves a mark on the land in the form of large guano deposits. This guano is an important nutrient source for terrestrial habitats of ice-free Antarctic areas, most notably by being the source of ammonia vapors which feed the surrounding grass, lichen and algae communities. Although investigated by researchers, the fate of the guano-associated microbial community and its role in decomposition processes remain vague. Therefore, by employing several direct community assessment methods combined with a broad culture-based approach we provide data on bacterial numbers, their activity and taxonomic affiliation in recently deposited and decayed Adelie penguin guano sampled at the Point Thomas rookery in Maritime Antarctica (King George Island). Our research indicates that recently deposited guano harbored mostly bacteria of penguin gut origin, presumably inactive in cold rookery settings. This material was rich in mesophilic enzymes active also at low temperatures, likely mediating early stage decomposition. Fresh guano colonization by environmental bacteria was minor, accomplished mostly by ammonia scavenging Jeotgalibaca sp. cells. Decayed guano contained 10-fold higher bacterial numbers with cold-active enzymes dominating the samples. Guano was colonized by uric-acid degrading and lipolytic Psychrobacter spp. and proteolytic Chryseobacterium sp. among others. Several spore-forming bacteria of penguin gut origin persisted in highly decomposed material, most notably uric-acid fermenting members of the Gottschalkiaceae family.

Pressurized intra-peritoneal aerosol chemotherapy (PIPAC) has been introduced to the clinical setting as a novel approach for the treatment of peritoneal metastasis. The local interaction of chemoaerosol droplets with the peritoneal surface as well as their distribution pattern is considered the main advantage over conventional liquid intraperitoneal chemotherapy. The aim of the present study was to investigate the behavior of these aerosol particles during PIPAC application via electron microscopy. Solutions of doxycycline, liposomal doxorubicin and macrophage cells were aerosolized using an established ex-vivo model. PIPAC was performed on peritoneum samples via microcatheter (MC) at a pressure of 12 mmHg C02 at 27°C. Following PIPAC the surface structure of applied particles was measured via electron microscopy. The aerosol particle contact of doxycyclin created a nanofilm of ~200 nm height on the peritoneal surface, and this height was revealed to be independent of the size of the initial particle hitting. These nanofilm blocks of ‘cylinders’ are of different diameters depending on the initial aerosol particle hitting that spot. Diameters of these ‘cylinders’ are far wider than the original diameter of the initial aerosol particle. However, coated particles such as liposomal doxorubicin and macrophages remained intact following contact with the peritoneal surface. Based on this and other data, the concept that aerosol particles exhibit a gas-like behavior in the abdomen creating a therapeutic capnoperitoneum should be revised. Fluid aerosol particles collide with the peritoneum creating a nanofilm. The interaction of pressurized intraperitoneal aerosol on the peritoneum is therefore closer to the distribution of a liquid film than to that of a gas. Further studies are required to further analyze the interaction of this nanofilm on the peritoneum.

The Antarctic and the Southern Ocean are a critically important part of the Earth system. The climatic, physical, and biological properties of this region are closely linked to other parts of the global environment. 200 years of direct human impact, recent climate amelioration and changes in the main sources and circulation of biogenic compounds as well as accumulation of industrial contaminants have significantly affected the whole ecosystem. Particularly sensitive is the region of the Western Antarctic Peninsula, which is considered to be one of the hot spots of the Earth. In this paper, we review recent literature and compare it with historical data to estimate and predict the consequences of this process. The Antarctic ecosystems can no longer be regarded as pristine. Global as well as local human influence has transgressed the barriers isolating that continent from the rest of the World, causing previously observed changes to accelerate.

Glaciers have recently been recognized as ecosystems comprised of several distinct habitats: a sunlit and oxygenated glacial surface, glacial ice, and a dark, mostly anoxic glacial bed. Surface meltwaters annually flood the subglacial sediments by means of drainage channels. Glacial surfaces host aquatic microhabitats called cryoconite holes, regarded as "hot spots" of microbial abundance and activity, largely contributing to the meltwaters' bacterial diversity. This study presents an investigation of cryoconite hole anaerobes and discusses their possible impact on subglacial microbial communities, combining 16S rRNA gene fragment amplicon sequencing and the traditional enrichment culture technique. Cryoconite hole sediment harbored bacteria belonging mainly to the Proteobacteria (21%), Bacteroidetes (16%), Actinobacteria (14%), and Planctomycetes (6%) phyla. An 8-week incubation of those sediments in Postgate C medium for sulfate reducers in airtight bottles, emulating subglacial conditions, eliminated a great majority of dominant taxa, leading to enrichment of the Firmicutes (62%), Proteobacteria (14%), and Bacteroidetes (13%), which consisted of anaerobic genera like Clostridium, Psychrosinus, Paludibacter, and Acetobacterium. Enrichment of Pseudomonas spp. also occurred, suggesting it played a role as a dominant oxygen scavenger, providing a possible scenario for anaerobic niche establishment in subglacial habitats. To our knowledge, this is the first paper to provide insight into the diversity of the anaerobic part of the cryoconite hole microbial community and its potential to contribute to matter turnover in anoxic, subglacial sites.

Articular cartilage dysfunctions are major cause of pain and disability and lead to serious health complications. Cell-based therapies are proposed as treatment methods for cartilage regeneration. In this study, we proposed polyurethane/poly(L-lactide-co-D, L-lactide)-based electrospun nonwovens as carriers for the delivery of human adipose-derived stromal stem cells. We found that 6:4 and 8:2 polyurethane/poly(L-lactide-co-D, L-lactide) initially enhance proliferative rate of human adipose-derived stromal stem cells, shorten their population doubling time, promote creation of functional chondrogenic nodules during chondrogenic differentiation, improve the collagen-2-to-collagen-1 protein ratio, and upregulate the expression of collagen-2 and aggrecan genes.

Despite recent great interest in glacier ecosystems in the continental Antarctic, little is known about their maritime counterparts. Our study presents descriptive data on cryoconite sediments and cryoconite holes on Ecology Glacier (King George Island) to accomplish three main objectives: (a) to identify main eukaryotic (algae, invertebrates) and prokaryotic (cyanobacteria) components of microbial communities; (b) to provide a “baseline” of community composition, organic matter and artificial contamination; and (c) to identify key abiotic factors that might be important in community assembly. Cryoconite holes were sampled along an altitudinal gradient of Ecology Glacier in January, mid Austral Summer 2017. Cryoconite holes located in lower altitude were deeper than those located in the middle and the highest altitude. Seventeen species of algae and cyanobacteria with biomass of 0.79 to 5.37 μg/cm3 have been found in sediments. Dominant species were cyanobacterial Pseudanabaena frigida and Bacillariophyceae Microcostaus sp. Biomass of Bacillariophyceae was significantly higher than that of Chlorophyta and Cyanobacteria. We found three species of rotifers (potentially two new to science) and for the first time a glacier dwelling Acari (suspension feeder, Nanorchestes nivalis). Organic matter content ranged from 5.4% to 7.6%. Investigated artificial radionuclides included 137Cs, 238Pu, 239+240Pu and 241Am. 210Pb seems to be related to organic matter content. Overall, cryoconite holes on Ecology Glacier present unique habitats that serve as biodiversity hotspots of psychrophiles, source of organic matter, matrices for radioactivity tracking and model for observing changes in supraglacial ecosystems in the maritime Antarctic.

(1) Background: Tannic acid is a plant-derived polyphenol showing antiviral activity mainly because of an interference with the viral adsorption. In this work, we tested whether the modification of silver nanoparticles with tannic acid (TA-AgNPs) can provide a microbicide with additional adjuvant properties to treat genital herpes infection. (2) Methods: The mouse model of the vaginal herpes simplex virus 2 (HSV-2) infection was used to test immune responses after treatment of the primary infection with TA-AgNPs, and later, after a re-challenge with the virus. (3) Results: The mice treated intravaginally with TA-AgNPs showed better clinical scores and lower virus titers in the vaginal tissues soon after treatment. Following a re-challenge, the vaginal tissues treated with TA-AgNPs showed a significant increase in the percentages of IFN-gamma+ CD8+ T-cells, activated B cells, and plasma cells, while the spleens contained significantly higher percentages of IFN-gamma+ NK cells and effector-memory CD8+ T cells in comparison to NaCl-treated group. TA-AgNPs-treated animals also showed significantly better titers of anti-HSV-2 neutralization antibodies in sera, and (4) Conclusions: Our findings suggest that TA-AgNPs sized 33 nm can be an effective anti-viral microbicide to be applied upon the mucosal tissues with additional adjuvant properties enhancing an anti-HSV-2 immune response following secondary challenge.

Cold-active bacteria of the genus Polaromonas (class Betaproteobacteria) are important components of glacial microbiomes. In this study, extrachromosomal replicons of 26 psychrotolerant Polaromonas strains, isolated from Arctic and Antarctic glaciers, were identified, sequenced, and characterized. The plasmidome of these strains consists of 13 replicons, ranging in size from 3,378 to 101,077 bp. In silico sequence analyses identified the conserved backbones of these plasmids, composed of genes required for plasmid replication, stable maintenance, and conjugal transfer. Host range analysis revealed that all of the identified plasmids are narrow-host-range replicons, only able to replicate in bacteria of closely related genera (Polaromonas and Variovorax) of the Comamonadaceae family. Special attention was paid to the identification of plasmid auxiliary genetic information, which may contribute to the adaptation of bacteria to environmental conditions occurring in glaciers. Detailed analysis revealed the presence of genes encoding proteins potentially involved in (i) protection against reactive oxygen species, ultraviolet radiation, and low temperatures; (ii) transport and metabolism of organic compounds; (iii) transport of metal ions; and (iv) resistance to heavy metals. Some of the plasmids also carry genes required for the molecular assembly of iron–sulfur [Fe-S] clusters. Functional analysis of the predicted heavy metal resistance determinants demonstrated that their activity varies, depending on the host strain. This study provides the first molecular insight into the mobile DNA of Polaromonas spp. inhabiting polar glaciers. It has generated valuable data on the structure and properties of a pool of plasmids and highlighted their role in the biology of psychrotolerant Polaromonas strains and their adaptation to the environmental conditions of Arctic and Antarctic glaciers.

Background: This ex-vivo study was performed to compare the impact of doxorubicin vs. liposomal doxorubicin on penetration depth in peritoneal tissue during Pressurized Intra-Peritoneal Aerosol Chemotherapy (PIPAC) via microcatheter (MC). Methods: Fresh post mortem swine peritoneum was cut into proportional sections. One group of samples was treated with PIPAC with Doxorubicin (D), and the other was treated with PIPAC with liposomal doxorubicin (LD). Tissue specimens were placed as follows: at the bottom of the plastic box (1), at the side wall (2), at the top cover (3) and the side of the box covered by a plastic tunnel (4). In-tissue doxorubicin penetration was measured using fluorescence microscopy on frozen thin sections. Results: Medium penetration levels with D were 325 µm (1), 152 µm (2), 84 µm (3) and 71 µm (4), respectively. Medium penetration levels with LD were significantly lower with 10 µm (1), 2 µm (2), 0 µm (3) and 0 µm (4), respectively. In most samples that were treated with LD no doxorubicin could be detected at all. Conclusion: Our data indicate that liposomal coating of doxorubicin and possibly other chemotherapeutical drugs might inhibit their interaction with the peritoneal surface. This inhibition appears to be relatively strong, since doxorubicin is partially undetectable due to liposomal coating. Further studies are warranted to investigate this interaction and its potential benefit in peritoneal applications.

In the present work, bacterial cellulose (BC) membranes have been modified with bioactive compounds based on long chain dimer of C18 linoleic acid, referred to as the dilinoleic acid (DLA) and tyrosine (Tyr), a natural amino acid capable of forming noncovalent cation−π interactions with positively charged ethylene diamine (EDA). This new compound, [EDA][DLA-Tyr], has been synthesized by simple coupling reaction, and its chemical structure was characterized by 1H NMR and Fourier transform infrared spectroscopy. The antimicrobial activity of a new compound against S. aureus and S. epidermidis, two cocci associated with skin and wound infections, was assessed. The [EDA][DLA-Tyr] impregnated BC exhibited strong and long-term antimicrobial activity against both staphylococcal species. The results showed a 57–66% and 56–60% reduction in S. aureus and S. epidermidis viability, respectively, depending on [EDA][DLA-Tyr] concentration used. Importantly, [EDA][DLA-Tyr] molecules were released gradually from the BC p...

Cold-active bacteria of the genus Polaromonas (class Betaproteobacteria) are important components of glacial microbiomes. In this study, extrachromosomal replicons of 26 psychrotolerant Polaromonas strains, isolated from Arctic and Antarctic glaciers, were identified, sequenced, and characterized. The plasmidome of these strains consists of 13 replicons, ranging in size from 3,378 to 101,077 bp. In silico sequence analyses identified the conserved backbones of these plasmids, composed of genes required for plasmid replication, stable maintenance, and conjugal transfer. Host range analysis revealed that all of the identified plasmids are narrow-host-range replicons, only able to replicate in bacteria of closely related genera (Polaromonas and Variovorax) of the Comamonadaceae family. Special attention was paid to the identification of plasmid auxiliary genetic information, which may contribute to the adaptation of bacteria to environmental conditions occurring in glaciers. Detailed analysis revealed the presence of genes encoding proteins potentially involved in (i) protection against reactive oxygen species, ultraviolet radiation, and low temperatures; (ii) transport and metabolism of organic compounds; (iii) transport of metal ions; and (iv) resistance to heavy metals. Some of the plasmids also carry genes required for the molecular assembly of iron–sulfur [Fe-S] clusters. Functional analysis of the predicted heavy metal resistance determinants demonstrated that their activity varies, depending on the host strain. This study provides the first molecular insight into the mobile DNA of Polaromonas spp. inhabiting polar glaciers. It has generated valuable data on the structure and properties of a pool of plasmids and highlighted their role in the biology of psychrotolerant Polaromonas strains and their adaptation to the environmental conditions of Arctic and Antarctic glaciers.

In recent years, glacial surfaces have received much attention as microbial habitats of diverse photoautotrophic and heterotrophic cells. Supraglacial ecosystems are annually covered and uncovered by snow. The aim of this study is to investigate the microbial community response to changing environmental conditions in a transect following the receding snow line on the surface of Ecology Glacier (King George Island, Antarctica). Parameters of surface ice and cryoconite holes included chemical composition of ice and sediment, Bacteria diversity by denaturating gradient gel electrophoresis, microbial functional diversity (Biolog Ecoplates), and microbial counts (epifluorescence microscopy, colony-forming units). Data demonstrated profound differences between surface ice and cryoconite holes. Changing environmental factors along the transect influenced composition and abundance of the microbiocenosis in both habitat types. Several parameters correlated positively with distance from the glacier edge, including the cell morphotype Shannon index, chlorophyll a, nitrogen, and seston concentrations. Suspended solid content positively correlated with microbial abundance and diversity. Nitrogen and phosphorus were limiting factors of microbial growth as amounts of organic nitrogen and phosphorus positively correlated with the cell numbers, fission rates, and photoautotroph contribution. Our findings indicate that microbial community shows a response in terms of abundance and diversity to exposure of the glacial surface as snow-cover melts. To our knowledge, this is the first study to recognize a microbial development pattern on a glacier surface in connection with the receding snow line. This may help better understand variability within supraglacial habitats, correct sampling procedures, and inform biocenotic development models.

Research concerning the elaboration and application of biomaterial which may support the nerve tissue regeneration is currently one of the most promising directions. Biocompatible polymer devices are noteworthy group among the numerous types of potentially attractive biomaterials for regenerative medicine application. Polylactides and polyurethanes may be utilized for developing devices for supporting the nerve regeneration, like nerve guide conduits or bridges connecting the endings of broken nerve tracts. Moreover, the combination of these biomaterial devices with regenerative cell populations, like stem or precursor cells should significantly improve the final therapeutic effect. Therefore, the composition and structure of final device should support the proper adhesion and growth of cells destined for clinical application. In current research, the three polymer mats elaborated for connecting the broken nerve tracts, made from polylactide, polyurethane and their blend were evaluated both for physical properties and in vitro, using the olfactory-bulb glial cells and mesenchymal stem cells. The evaluation of Young's modulus, wettability and roughness of obtained materials showed the differences between analyzed samples. The analysis of cell adhesion, proliferation and morphology showed that the polyurethane–polylactide blend was the most neutral for cells in culture, while in the pure polymer samples there were significant alterations observed. Our results indicated that polyurethane–polylactide blend is an optimal composition for culturing and delivery of glial and mesenchymal stem cells.

Surface ice and cryoconite holes of two types of polythermal Svalbard Glaciers (Hans Glacier—grounded tidewater glacier and Werenskiold Glacier—land-based valley glacier) were investigated in terms of chemical composition, microbial abundance and diversity. Gathered data served to describe supraglacial habitats and to compare microbe–environment interactions on those different type glaciers. Hans Glacier samples displayed elevated nutrient levels (DOC, nitrogen and seston) compared to Werenskiold Glacier. Adjacent tundra formations, bird nesting sites and marine aerosol were candidates for allochtonic enrichment sources. Microbial numbers were comparable on both glaciers, with surface ice containing cells in the range of 104 mL−1 and cryoconite sediment 108 g−1 dry weight. Denaturating gradient gel electrophoresis band-based clustering revealed differences between glaciers in terms of dominant bacterial taxa structure. Microbial community on Werenskiold Glacier benefited from the snow-released substances. On Hans Glacier, this effect was not as pronounced, affecting mainly the photoautotrophs. Over-fertilization of Hans Glacier surface was proposed as the major factor, desensitizing the microbial community to the snow melt event. Nitrogen emerged as a limiting factor in surface ice habitats, especially to Eukaryotic algae. Electronic supplementary material The online version of this article (doi:10.1007/s00792-015-0764-z) contains supplementary material, which is available to authorized users.

The olfactory bulb (OB) is a unique structure in the central nervous system that retains the ability to create new neuronal connections. Glial cells isolated from the OB have been recently considered as a novel and promising tool to establish an effective therapy for central nervous system injuries. Due to the hindered access to autologous tissue for cell isolation, an allogeneic source of tissues obtained postmortem has been proposed. In this study, we focused on the morphological and molecular characteristics of human OB-derived glial cells isolated postmortem, at different time points after a donor's death. We evaluated the proliferative activity of the isolated cells, and investigated the ultrastructure of the mitochondria, the accumulation of intracellular reactive oxygen species, and the activity of superoxide dismutase. The data obtained clearly indicate that the duration of ischemia is crucial for the viability/senescence rate of OB-derived glial cells. The OB can be isolated during autopsy and still stand as a source of viable glial cells, but ischemia duration is a major factor limiting its potential usefulness in therapies.

Metformin, the popular anti-diabetic drug was shown to exert multiple biological effects. The most recent metformin gained attention as an agent that mobilizes endogenous progenitor cells and enhances regenerative potential of organisms, for example by promoting neurogenesis. In the present study, we examined the role of metformin on mouse olfactory ensheathing cells (mOECs) derived from animals receiving metformin for eight weeks at a concentration equal to 2.8 mg/day. The mOECs expanded ex vivo were characterized in terms of their cellular phenotype, morphology, proliferative activity, viability and accumulation of oxidative stress factors. Moreover, we determined the mRNA and protein levels of brain-derived neurotrophic factor (BDNF), distinguishing the secretion of BDNF by mOECs in cultures and circulating serum levels of BDNF. The mOECs used in the experiment were glial fibrillary acidic protein (GFAP) and p75 neurotrophin receptor (p75NTR) positive and exhibited both astrocyte-like and non-myelin Schwann cell-like morphologies. Our results revealed that the proliferation of OECs derived from mice treated with metformin was lowered, when compared to control group. Simultaneously, we noted increased cell viability, reduced expression of markers associated with cellular senescence and a decreased amount of reactive oxygen species. We observed increased mRNA expression of BDNF and its down-stream genes. Obtained results indicate that metformin may exert antioxidant, anti-apoptotic and senolytic action on OECs expanded ex vivo.

The objective of this study was to determine biocompatibility of zirconia-based coatings obtained by the sol–gel method. Two matrices, ZrO2 and SiO2/ZrO2, were created and applied on stainless steel type 316L with dip-coating technique. The morphology and topography of biomaterials’ surface were characterized using energy-dispersive X-ray spectroscopy and atomic force microscopy, while chemical composition was analyzed by Raman spectroscopy. Additionally, wettability and surface free energy were characterized. Biocompatibility of obtained biomaterials was evaluated using an in vitro model employing mesenchymal stem cells (MSCs) of adipose and bone marrow origin. Biological analysis included determination of proliferation activity and morphology of MSCs in cultures on synthesized biomaterials. Osteoinductive properties of biomaterials were determined both in non-osteogenic, as well as osteogenic conditions. The results showed that investigated biomaterials exerted different impact on MSCs. Biomaterial with ZrO2 layer was more biocompatible for adipose-derived MSCs, while SiO2/ZrO2 layer promoted proliferation of bone marrow derived MSCs. Moreover, hybrid coating exhibited greater osteoinductive properties than ZrO2 coating, both on cultures with adipose-derived stromal (stem) cells and bone marrow stromal cells. Observed biological effects may result not only from different chemical composition, but also from diverse wettability. The ZrO2 coating was characterized as hydrophobic layer, while SiO2/ZrO2 exhibited hydrophilic properties. The results obtained suggest that behavior of MSCs in response to the biomaterial may vary depending on their origin, therefore we postulate, that screening analysis of implants’ biocompatibility, should incorporate model applying both adipose- and bone marrow derived MSCs.

The diversity of polyhydroxyalkanoates-producing bacteria in freshwater reservoirs in the Ecology Glacier foreland, Antarctica, was examined by a cultivation-dependent method. Isolated strains were analyzed phylogenetically by 16S rRNA gene sequencing, and classified as members of Alpha-, Beta-, or Gammaproteobacteria classes. Polymerase chain reaction was used to detect PHA synthase genes. Potential polyhydroxyalkanoates (PHAs) producers belonging mainly to Pseudomonas sp., and Janthinobacterium sp. were isolated from all five sampling sites, suggesting that PHA synthesis is a common bacterial feature at pioneer sites. All Pseudomonas strains had the genetic potential to synthesize medium-chain-length PHAs, whereas some isolated Janthinobacterium strains might produce short-chain-length PHAs or medium-chain-length PHAs. It is the first report revealing that Janthinobacterium species could have the potential to produce medium-chain-length PHAs.

We determined sulphate-reducing activities in media inoculated with soils and with kettle lake sediments in order to investigate their potential in geomicrobiological processes in low-temperature, terrestrial maritime Antarctic habitats. Soil and sediment samples were collected in a glacier valley abandoned by Ecology Glacier during the last 30 years: from a new formed kettle lake sediment and forefield soil derived from ground moraine. Inoculated with these samples, liquid Postgate C and minimal media supplemented with various carbon sources as electron donors were incubated for 8 weeks at 4°C. High rates of sulphate reduction were observed only in media inoculated with soil. No sulphate reduction was detected in media inoculated with kettle lake sediments. In soil samples culture media calcite and elemental sulphur deposits were observed, demonstrating that sulphate-reducing activity is associated with a potential to mineral formation in cold environments. Cells observed on scanning microscopy (SEM) micrographs of post-culture-soil deposits could be responsible for sulphate-reducing activity.

El sistema nervioso central de los reptiles tiene la capacidad de crecer y regenerarse durante la vida adulta del animal. Por lo tanto, las celulas de SNC creadas de esta clase de animales deberian componerse de sustancias o moleculas que permiten la neuroregeneracion. Las celulas que participan directamente en este proceso no han sido claramente caracterizadas, especialmente en el entorno de cultivo celular. La morfologia de las celulas adherentes gliales de reptiles deben ser reconocidas y diferenciarse respecto a las celulas del SNC de mamiferos. Se aislaron celulas gliales del bulbo olfatorio y el cerebro del Gecko (Eublepharis macularius) y se cultivaron por separado. Se observaron poblaciones de celulas con capacidad proliferativa en ambos tipos de cultivos. Ademas, se detectaron moleculas de depositos lipidicos dentro de su citoplasma, y su localizacion se correlaciono con la posicion de las mitocondrias. Esta informacion puede ser util en la busqueda de nuevas sustancias bioactivas que participan en la regeneracion del sistema nervioso central.

Pseudomonas sp. GLE121 (a psychrophilic Antarctic strain) carries three plasmids: pGLE121P1 (6899 bp), pGLE121P2 (8330 bp) and pGLE121P3 (39,583 bp). Plasmids pGLE121P1 and pGLE121P2 show significant sequence similarity to members of the IncP-9 and IncP-7 incompatibility groups, respectively, while the largest replicon, pGLE121P3, is highly related to plasmid pNCPPB880-40 of Pseudomonas syringae pathovar tomato NCPPB880. All three plasmids have a narrow host range, limited to members of the genus Pseudomonas. Plasmid pGLE121P3 encodes a conjugal transfer system, while pGLE121P1 carries only a putative MOB module, conserved in many mobilizable plasmids. Plasmid pGLE121P3 contains an additional load of genetic information, including a pair of genes with homology to the rulAB operon, responsible for ultraviolet radiation (UVR) tolerance. Given the increasing UV exposure in Antarctic regions, the expression of these genes is likely to be an important adaptive response.

Novel potential antibacterial agents derived from ciprofloxacin (HCp) were synthesized in the reaction of this antibiotic with hydroxymethyldiphenylphosphine. Detailed analysis by the NMR, IR and MS techniques attested to the identity and structure of the obtained compounds. In addition, the structure of phosphine PPh2CH2-Cp was unambiguously confirmed by X-ray crystal structural analysis. PPh2CH2-Cp exhibited an antibacterial activity comparable to that of the original drug. Cytotoxicity studies revealed that this compound was characterized by lower toxicity against mammalian cells than HCp. Besides, it did not induce a morphological change in cells after its action and was unable to degrade plasmid DNA, as well as parent antibiotic. Our results open up new possibilities in designing novel, less toxic and comparably effective antibiotics drugs.

The aim of this work was to assess the effect of different stabilizing agents, for example, polyethylenimine (PEI) and polyvinylpyrrolidone (PVP), on gold nanoparticles (AuNPs) and their influence on equine platelet activation and release of particular growth factors. The gold nanoparticles were produced by chemical reduction of chloroauric acid. UV-Vis spectroscopy confirmed the presence of gold nanoparticles in investigated solutions. The AuNPs were incubated with whole blood at various concentrations. The morphology of platelets in PRP prepared from the blood incubated with AuNPs was characterized by scanning transmission electron microscopy, whereas the concentrations of growth factors and cytokines were evaluated by ELISA assays. The most promising results were obtained with equine platelets incubated with 5% AuNPs stabilized by PEI, which lead to secretion of bone morphogenetic protein 2 (BMP-2), vascular endothelial growth factor (VEGF), and fibroblast growth factor 1 (FGF-1) and simultaneously cause decrease in concentration of interleukin-1 alpha (IL-1α). The qRT-PCR confirmed ELISA test results. The incubation with 5% AuNPs stabilized by PEI leads to upregulation of BMP-2 and VEGF transcripts of mRNA level and to downregulating expression of interleukin-6 (IL-6). Obtained data shed a promising light on gold nanoparticle application for future regenerative medicine application.

The aim of this work was to assess the effect of different stabilizing agents, for example, polyethylenimine (PEI) and polyvinylpyrrolidone (PVP), on gold nanoparticles (AuNPs) and their influence on equine platelet activation and release of particular growth factors. The gold nanoparticles were produced by chemical reduction of chloroauric acid. UV-Vis spectroscopy confirmed the presence of gold nanoparticles in investigated solutions. The AuNPs were incubated with whole blood at various concentrations. The morphology of platelets in PRP prepared from the blood incubated with AuNPs was characterized by scanning transmission electron microscopy, whereas the concentrations of growth factors and cytokines were evaluated by ELISA assays. The most promising results were obtained with equine platelets incubated with 5% AuNPs stabilized by PEI, which lead to secretion of bone morphogenetic protein 2 (BMP-2), vascular endothelial growth factor (VEGF), and fibroblast growth factor 1 (FGF-1) and simultaneously cause decrease in concentration of interleukin-1 alpha (IL-1α). The qRT-PCR confirmed ELISA test results. The incubation with 5% AuNPs stabilized by PEI leads to upregulation of BMP-2 and VEGF transcripts of mRNA level and to downregulating expression of interleukin-6 (IL-6). Obtained data shed a promising light on gold nanoparticle application for future regenerative medicine application.

Equine metabolic syndrome (EMS) is mainly characterized by insulin resistance, obesity, and local or systemic inflammation. That unfriendly environment of adipose tissue has huge impact on stem cells population (ASC) residing within. In the present study, using molecular biology techniques and multiple imaging techniques (SEM, FIB-SEM, and confocal microscopy), we evaluated the impact of EMS on ASC viability and chondrogenic differentiation. Moreover, we visualized the mitochondrial network and dynamics in ASCCTRLand ASCEMSduring control and chondrogenic conditions. In control conditions, ASCEMSwere characterized by increased mitochondrial fission in comparison to ASCCTRL. We found that extensive remodeling of mitochondrial network including fusion and fission occurs during early step of differentiation. Moreover, we observed mitochondria morphology deterioration in ASCEMS. These conditions seem to cause autophagic shift in ASCEMS, as we observed increased accumulation of LAMP2 and formation of multiple autophagosomes in those cells, some of which contained dysfunctional mitochondria. “Autophagic” switch may be a rescue mechanism allowing ASCEMSto clear impaired by ROS proteins and mitochondria. Moreover it provides a precursors-to-macromolecules synthesis, especially during chondrogenesis. Our data indicates that autophagy in ASCEMSwould be crucial for the quality control mechanisms and maintenance of cellular homeostasis ASCEMSallowing them to be in “stemness” status.

Background Osteogenic differentiation of mesenchymal stem cells has been extensively investigated with regards to different aspects, including the analysis of cell intracellular and extracellular proteome, cell gene expression pattern, and morphology. During the osteogenic differentiation, osteoblasts produce and release specific proteins, like osteocalcin and osteopontin. Simultaneously, cells produce the extracellular matrix (ECM) that resembles the bone ECM, with high quantity of calcium and phosphorus. We focused on the ultrastructural changes occurring during the osteogenic differentiation of MSC cultured in alginate hydrogel. Results The analysis revealed that during the osteogenic differentiation the most of cells become dead, and these dead cells contain large quantities of calcium and deposition is strictly connected with the cellular death and small membrane vesicles released by cells. Cell organelles were not present within differentiated cells, while in cells from non-osteogenic group the cellular ultrastructure was proper, with single nuclei, endoplasmic reticulum and numerous mitochondria. Conclusion The ECM synthesis and deposition during the osteogenic differentiation of MSC involves cellular programmed death. The small membrane vesicles become the mineralization sites of formed bone ECM. Electronic supplementary material The online version of this article (doi:10.1186/s13578-016-0128-0) contains supplementary material, which is available to authorized users.

Cartilage and bone tissue injuries are common targets in regenerative medicine. The degeneration of cartilage tissue results in tissue loss with a limited ability to regenerate. However, the application of mesenchymal stem cells in the course of such condition makes it possible to manage this disorder by improving the structure of the remaining tissue and even stimulating its regeneration. Nevertheless, in the case of significant tissue loss, standard local injection of cell suspensions is insufficient, due to the low engraftment of transplanted cells. Introduction of mesenchymal stem cells on the surface of a compatible biomaterial can be a promising tool for inducing the regeneration by both retaining the cells at the desired site and filling the tissue gap. In order to obtain such a cell-biomaterial hybrid, we developed complex, biphasic polymer blend biomaterials composed of various polyurethane (PU)-to-polylactide (PLA) ratios, and doped with different concentrations of nano-hydroxyapatite (nHAp). We have determined the optimal blend composition and nano-hydroxyapatite concentration for adipose mesenchymal stem cells cultured on the biomaterial. We applied biological in vitro techniques, including cell viability assay, determination of oxidative stress factors level, osteogenic and chondrogenic differentiation potentials as well as cell proteomic analysis. We have shown that the optimal composition of biphasic scaffold was 20:80 of PU:PLA with 20% of nHAp for osteogenic differentiation, and 80:20 of PU:PLA with 10% of nHAp for chondrogenic differentiation, which suggest the optimal composition of final biphasic implant for regenerative medicine applications.

Polymeric biomaterials based on polyurethane and polylactide blends are promising candidates for regenerative medicine applications as biocompatible, bioresorbable carriers. In current research we showed that 80/20 polyurethane/polylactide blends (PU/PLDL) with confirmed biological properties in vitro may be further improved by the addition of ZnO nanoparticles for the delivery of bioactive zinc oxide for cells. The PU/PLDL blends were doped with different concentrations of ZnO (0.001%, 0.01%, 0.05%) and undertaken for in vitro biological evaluation using human adipose stromal stem cells (ASCs) and olfactory ensheathing cells (OECs). The addition of 0.001% of ZnO to the biomaterials positively influenced the morphology, proliferation, and phenotype of cells cultured on the scaffolds. Moreover, the analysis of oxidative stress markers revealed that 0.001% of ZnO added to the material decreased the stress level in both cell lines. In addition, the levels of neural-specific genes were upregulated in OECs when cultured on sample 0.001 ZnO, while the apoptosis-related genes were downregulated in OECs and ASCs in the same group. Therefore, we showed that PU/PLDL blends doped with 0.001% of ZnO exert beneficial influence on ASCs and OECs in vitro and they may be considered for future applications in the field of regenerative medicine.

The Svalbard archipelago (Spitsbergen Island) is the northernmost landmass in the European Arctic and has a variety of small- and medium-sized glaciers. The plasmidome of eleven psychrophilic strains of Variovorax spp. isolated from the ice surface of Hans and Werenskiold Glaciers of Spitsbergen Island, was defined. This analysis revealed the presence of six plasmids whose nucleotide sequences have been determined. Four of them, exhibiting high reciprocal sequence similarity, possess unique structures, since their genomes lack any recognized genes. These miniature replicons, not exceeding 1 kb in size, include pHW69V1 (746 bp), which is the smallest autonomous replicon so far identified in free-living bacteria. The miniature plasmids share no similarity with known sequences present in the databases. In silico and experimental analyses identified conserved DNA regions essential for the initiation of replication of these replicons.

Glacier forelands are excellent sites in which to study microbial succession because conditions change rapidly in the emerging soil. Development of the bacterial community was studied along two transects on lateral moraines of Ecology Glacier, King George Island, by culture-dependent and culture-independent approaches (denaturating gradient gel electrophoresis). Environmental conditions such as cryoturbation and soil composition affected both abundance and phylogenetic diversity of bacterial communities. Microbiocenosis structure along transect 1 (severe cryoturbation) differed markedly from that along transect 2 (minor cryoturbation). Soil physical and chemical factors changed along the chronosequence (time since exposure) and influenced the taxonomic diversity of cultivated bacteria, particularly along transect 2. Arthrobacter spp. played a pioneer role and were present in all soil samples, but were most abundant along transect 1. Cultivated bacteria isolated from transect 2 were taxonomically more diverse than those cultivated from transect 1; those from transect 1 tended to express a broader range of enzyme and assimilation activities. Our data suggest that cryoturbation is a major factor in controlling bacterial community development in postglacial soils, shed light on microbial succession in glacier forelands, and add a new parameter to models that describe succession phenomena.

Background and objectives AD-MSCs (adipose-derived mesenchymal stem cells), as an easy obtainable population of multipotent cells, have been successfully applied in many diseases in animals. Having very similar properties and morphology to these collected from bone marrow, are very attractive object for regenerative medicine. Conclusions Ovine subcutaneous fat from many regions of the body is rich source of stem cells, which could be used in locomotive system disorders experimental therapy on sheep models.