Mn-based methacrylated gellan gum hydrogels for MRI-guided cell delivery and imaging

This work aims to engineer a new stable injectable Mn-based methacrylated gellan gum (Mn/GG-MA) hydrogel for real-time monitored cell delivery into the central nervous system. To enable the hydrogel visualization under Magnetic Resonance Imaging (MRI), GG-MA solutions were supplemented with paramagnetic Mn2+ ions before its ionic crosslink with artificial cerebrospinal fluid (aCSF). The resulting formulations were stable, detectable by T1-weighted MRI scans and also injectable. Cell-laden hydrogels were prepared using the Mn/GG-MA formulations, extruded into aCSF for crosslink, and after 7 days of culture, the encapsulated human adipose-derived stem cells remained viable, as assessed by Live/Dead assay. In vivo tests, using double mutant MBPshi/shi/rag2 immunocompromised mice, showed that the injection of Mn/GG-MA solutions resulted in a continuous and traceable hydrogel, visible on MRI scans. Summing up, the developed formulations are suitable for both non-invasive cell delivery techniques and image-guided neurointerventions, paving the way for new therapeutic procedures.Sílvia Vieira acknowledges the FCT Ph.D. scholarship (SFRH/BD/102710/2014). J. Miguel Oliveira and J. Silva-Correia acknowledge the FCT grants under the Investigator FCT program (IF/01285/2015 and IF/00115/2015, respectively). The authors also acknowledge the funds provided under the project NanoTech4ALS, funded under the EU FP7 M-ERA.NET program, and ESF (POWR.03.02.00-00-I028/17-00)

The Potential Role of Metalloproteinases in Neurogenesis in the Gerbil Hippocampus Following Global Forebrain Ischemia

BACKGROUND: Matrix metalloproteinases (MMPs) have recently been considered to be involved in the neurogenic response of adult neural stem/progenitor cells. However, there is a lack of information showing direct association between the activation of MMPs and the development of neuronal progenitor cells involving proliferation and/or further differentiation in vulnerable (Cornus Ammoni-CA1) and resistant (dentate gyrus-DG) to ischemic injury areas of the brain hippocampus. PRINCIPAL FINDINGS: We showed that dynamics of MMPs activation in the dentate gyrus correlated closely with the rate of proliferation and differentiation of progenitor cells into mature neurons. In contrast, in the damaged CA1 pyramidal cells layer, despite the fact that some proliferating cells exhibited antigen specific characteristic of newborn neuronal cells, these did not attain maturity. This coincides with the low, near control-level, activity of MMPs. The above results are supported by our in vitro study showing that MMP inhibitors interfered with both the proliferation and differentiation of the human neural stem cell line derived from umbilical cord blood (HUCB-NSCs) toward the neuronal lineage. CONCLUSION: Taken together, the spatial and temporal profiles of MMPs activity suggest that these proteinases could be an important component in neurogenesis-associated processes in post-ischemic brain hippocampus

Biological and chemical corrosion of cement materials modified with polymer

The article presents the effect of the addition of polymer to mortars with CEMI and its influence on durability under conditions of sulfuric acid or nitric and sulphur bacteria or nitrogen (nitrification and denitrification). Both acids corresponds to the products of metabolism of bacteria Acidithiobacillus thiooxidans and Thiobacillus denitrificans, Paracoccus denitrificans by the literature is about 0.15 mmol/dm3. The changes in tightness materials studied by determining moisture mass and absorption. Corrosion processes were identified by examination in a scanning microscope equipped with an X-ray microanalyzer and a mercury porosimeter. The research results presented showed that the solution has a significantly weaker effect on the composite cement and cement-polymer compared with the action of bacteria. The action of both environments caused two opposing processes: unsealing the structure and deposition of corrosion products

Not that Dry a Land. The Specificity of Settlement in the Floodplains of the Middle Vistula Valley on the Example of the Settlement Cluster in Glinki, Otwock County

Floodplains of large rivers are rarely the subject of archaeological research. The excavations at the cemetery of the Przeworsk culture at Czersk, Piaseczno County, and studies on the modern settlement in the Urzecze (literally at-the-river’s) microregion near Warsaw yielded data about the settlement in the Middle Vistula Valley across the ages and prompted a non-invasive examination of the area. In 2017, a large-scale fieldwalking survey took place in the southern part of the Urzecze floodplain, covering an area of ca. 83 square kilometres (Figs. 1, 2). The already known sites were verified, and numerous new sites from various historical periods were discovered. The survey was complemented with traditional research, such as cartographical and historical searches, as well as new solutions in the form of a digital elevation model, obtained by laser scanning of the ground surface and geophysical and underwater prospection. The character of settlement in the area, specific due to the natural conditions, can be illustrated on the example of the settlement cluster near the village of Glinki, situated on the right bank of the Vistula, at the latitude of Góra Kalwaria (Fig. 3). Settlement in periodically flooded areas is focused only in a few selected places, where the shape of the terrain guarantees relatively safe shelter during periods of regular but hard to predict overflows and dangerous inundations. In the case of the cluster in Glinki, small, elevated areas, difficult to notice in the field and surrounded by oxbow lakes that form natural reservoirs (polders), are legible (Fig. 4). The oldest traces of settlement date back to the Bronze Age and Early Iron Age, then to the pre-Roman and Roman period and the Middle Ages, up to modern and contemporary times (Fig. 5, 6). The ‘insular’ nature of settlement (Fig. 9) in the floodplains of the Middle Vistula is confirmed by the observed presence of other, similar clusters situated on the former sandbanks and islands or their remains. The specificity of natural conditions (Fig. 7, 8, 10) and the rhythm of life in these areas influenced the flavour and specificity of the local culture, a phenomenon that has been well described for modern times (Ł.M. Stanaszek 2014). It is possible that in the earlier time periods some local differences within the large archaeological cultures are also to be expected. This can only be confirmed by future excavations in the area

Post-Meroitic cemetery at the Khor Shambat site in Sudan

Archaeological research at the Khor Shambat site located in Omdurman in central Sudan has been conducted since 2012, when a team of scientists from the Institute of Archaeology and Ethnology Polish Academy of Sciences (Poznań) launched a salvage exploration of a Neolithic site and cemetery damaged by road construction. Research is now conducted within the scope of a grant from the National Science Centre, Poland (No. 2015/17/D/HS3/01492). Three seasons of fieldwork since 2016 have focused on the extensive prehistoric settlement spanning nearly 4000 years, from the early Mesolithic to the late Neolithic. The site turned out to be attractive not only for Mesolithic hunters-gatherers and Neolithic shepherds, but also as a burial place for the Meroitic and post-Meroitic inhabitants of the region. A survey of about 1% of the surface of the Khor Shambat site (KSH 1) resulted in the discovery of 66 graves; 12 of these are probably post-Meroitic, and of these three presented a rich and interesting array of burial goods, including imports from the Far East. At the same time, KSH 1 is one of the southernmost post-Meroitic cemeteries

Contribution to the bryoflora of the Roztocze National Park (SE Poland)– Bryophytes of the Świerszcz river valley

New distribution data for 171 bryophyte taxa in the Roztocze National Park are provided. Among them there are 43 species protected by law in Poland, including 20 strictly protected species, as well as 13 species threatened in Poland. The research revealed 36 species (5 liverworts and 31 mosses) new for the region. Noteworthy is the occurrence of 19 mountain species and 10 bryophytes thought to be relicts of old-growth forests what confirms the specificity of nature of the Roztocze region. The most valuable and interesting finds are: mosses Campylophyllopsis sommerfeltii (Myrin) Ochyra, Dicranum viride (Sull. & Lesq.) Lindb., Buxbaumia viridis (Moug. ex Lam. & DC.) Brid. ex Moug. & Nestl. as well as liverworts Calypogeia suecica (Arnell et J. Perss.) Müll. Frib. and Cephalozia catenulata (Huebener) Lindb. A brief characterisations of these species are presented

Methacrylated gellan gum and hyaluronic acid hydrogel blends for image-guided neurointerventions

Cell-based therapies deliveredviaintrathecal injection are considered as one of the most promisingsolutions for the treatment of amyotrophic lateral sclerosis (ALS). Herein, injectable manganese-basedbiocompatible hydrogel blends were developed, that can allow image-guided cell delivery. Thehydrogels can also provide physical support for cells during injection, and at the intrathecal space aftertransplantation, while assuring cell survival. In this regard, different formulations of methacrylated gellangum/hyaluronic acid hydrogel blends (GG-MA/HA) were considered as a vehicle for cell delivery. Thehydrogels blends were supplemented with paramagnetic Mn2+to allow a real-time monitorization ofhydrogel depositionvia T1-weighted magnetic resonance imaging (MRI). The developed hydrogels wereeasily extruded and formed a stable fiber upon injection into the cerebrospinal fluid. Hydrogels preparedwith a 75 : 25 GG-MA to HA ratio supplemented with MnCl2at 0.1 mM showed controlled hydrogeldegradation, suitable permeability, and a distinct MRI signalin vitroandin vivo. Additionally, human-derived adipose stem cells encapsulated in 75 : 25 GG-MA/HA hydrogels remained viable for up to14 days of culturein vitro. Therefore, the engineered hydrogels can be an excellent tool for injectableimage-guided cell delivery approaches.Sı´lvia Vieira acknowledges the FCT PhD scholarship (SFRH/BD/102710/2014). The FCT distinction attributed to J. Miguel Oliveira under the Investigator FCT program (IF/01285/2015) and J. Silva-Correia (IF/00115/2015) are also greatly acknowledged. The authors also acknowledge the funds provided under the project NanoTech4ALS, funded under the EU FP7 M-ERA.NET program, and ESF (POWR.03.02.00-00-I028/17-00)