Biomaterials and Stem Cells: Promising Tools in Tissue Engineering and Biomedical Applications

Biomaterial sciences and tissue engineering approaches are currently fundamental strategies for the development of regenerative medicine. Stem cells (SCs) are a unique cell type capable of self‐renewal and reconstructing damaged tissues. At the present time, adult SCs isolated from postnatal tissues are widely used in clinical applications. Their characteristics such as a multipotent differentiation capacity and immunomodulatory activity make them a promising tool to use in patients. Modern material technologies allow for the development of innovative biomaterials that closely correspond to requirements of the current biomedical application. Biomaterials, such as ceramics and metals, are already used as implants to replace or improve the functionality of the damaged tissue or organ. However, the continuous development of modern technology opens new insights of polymeric and smart material applications. Moreover, biomaterials may enhance the SCs biological activity and their implementation by establishing a specific microenvironment mimicking natural cell niche. Thus, the synergistic advancement in the fields of biomaterial and medical sciences constitutes a challenge for the development of effective therapies in humans including combined applications of novel biomaterials and SCs populations

Zakres orzekania w sprawach o zadośćuczynienie pieniężne za doznaną krzywdę – uwagi na tle uchwały Sądu Najwyższego z dnia 11 kwietnia 2019 r. (III CZP 105/18, BSN 2019, nr 4, s. 8)

The purpose of this study is to analyze legal issues related to the scope of adjudication in cases of pecuniary compensation for the harm suffered, especially in a situation in which the party objected that the injured party contributed to the damage, and in a situation in which the claim submitted in the lawsuit was of a lower amount than the potentially “adequate compensation”. The principle of ne eat iudex ultra petita partium means that the court may decide only on what is claimed submitted by the party requesting legal protection. The scope of the requested legal protection thus sets the boundaries of the subject of the decision. At the same time, the assumption that there should be complete agreement between the subject of the proceedings and the subject of the ruling, i.e. what covers the subject of the decision, should be considered correct. As a result, it must be recognized that there are a close relationship and interdependence between limiting the court with what is claimed and the subject matter of the dispute. In determining the claim, the plaintiff thus sets the boundaries of the subject of the dispute, and limiting the court with what is claimed is tantamount to limiting the subject of the dispute.Celem niniejszego opracowania jest analiza zagadnień prawnych związanych z zakresem orzekania w sprawach o zadośćuczynienie pieniężne za doznaną krzywdę, zwłaszcza w sytuacji, w której strona podniosła zarzut przyczynienia się poszkodowanego do powstania szkody, a żądanie zgłoszone w pozwie obejmowało kwotę niższą od potencjalnie „odpowiedniego zadośćuczynienia”. Obowiązywanie zasady ne eat iudex ultra petita partium oznacza, że sąd może orzec wyłącznie o tym, co zostało objęte żądaniem przedstawionym przez podmiot występujący z wnioskiem o udzielenie ochrony prawnej. Niniejsza analiza prowadzi do wniosku, że zakres żądanej ochrony prawnej wyznacza granice przedmiotu rozstrzygnięcia. Jednocześnie za prawidłowe należy uznać założenie, że powinna istnieć całkowita zgodność między przedmiotem procesu a przedmiotem orzekania, tj. tym, co obejmuje przedmiot rozstrzygnięcia. W rezultacie należy stwierdzić, że istnieje ścisły związek i współzależność pomiędzy związaniem sądu granicami żądania a problematyką przedmiotu sporu. Określając żądanie, powód wyznacza więc granice przedmiotu sporu, a związanie sądu przedstawionym żądaniem jest równoznaczne ze związaniem przedmiotem sporu

The strategy of fusion genes construction determines efficient expression of introduced transcription factors

The main goal in gene therapy and biomedical research is an efficient transcription factors (TFs) delivery system. SNAIL, a zinc finger transcription factor, is strongly involved in tumor, what makes its signaling pathways an interesting research subject. The necessity of tracking activation of intracellular pathways has prompted fluorescent proteins usage as localization markers. Advanced molecular cloning techniques allow to generate fusion proteins from fluorescent markers and transcription factors. Depending on fusion strategy, the protein expression levels and nuclear transport ability are significantly different. The P2A self-cleavage motif through its cleavage ability allows two single proteins to be simultaneously expressed. The aim of this study was to compare two strategies for introducing a pair of genes using expression vector system. We have examined GFP and SNAI1 gene fusions by comprising common nucleotide polylinker (multiple cloning site) or P2A motif in between them, resulting in one fusion or two independent protein expressions respectively. In each case transgene expression levels and translation efficiency as well as nuclear localization of expressed protein have been analyzed. Our data showed that usage of P2A motif provides more effective nuclear transport of SNAIL transcription factor than conventional genes linker. At the same time the fluorescent marker spreads evenly in subcellular space

MET receptor is a potential therapeutic target in high grade cervical cancer

Cervical cancer is one of the leading causes of death among women suffering from tumors. Current treatment options are insufficient. Here, we investigated the MET receptor as a potential molecular target in advanced cervical cancer. Downregulation of MET receptor expression via RNA interference in different cervical carcinoma cell lines dramatically decreased tumor growth and forced tumor differentiation in vivo. MET receptor silencing also led to a dramatic decrease in cell size and a decrease in proliferation rate under normal and stress conditions. MET receptor downregulation also resulted in decreased cyclin D1 and c-myc levels but did not increase apoptosis. Subsequent experiments showed that downregulation of the MET receptor decreased the expression of a key regulator of the epithelial-to-mesenchymal transition, SLUG. and increased the expression of E-cadherin, a hallmark of the epithelial phenotype. Moreover, MET downregulation impairs expression and signaling of CXCR4 receptor, responsible for invasive phenotype. Taken together, our results strongly suggest that the MET receptor influences the oncogenic properties of cervical carcinoma cells in vitro and in vivo. These findings highlight a unique role of the MET receptor in cervical carcinoma cells and indicate the MET receptor as a potential therapeutic target for advanced cervical carcinoma

The role of G-protein-coupled membrane estrogen receptor in mouse Leydig cell function : in vivo and in vitro evaluation

AbstractIn this study, G-coupled estrogen receptor (GPER) was inactivated, by treatment with antagonist (G-15), in testes of C57BL/6 mice: immature (3 weeks old), mature (3 months old) and aged (1.5 years old) (50 μg/kg bw), as well as MA-10 mouse Leydig cells (10 nM/24 h) alone or in combination with 17β-estradiol or antiestrogen (ICI 182,780). In G-15-treated mice, overgrowth of interstitial tissue was found in both mature and aged testes. Depending on age, differences in structure and distribution of various Leydig cell organelles were observed. Concomitantly, modulation of activity of the mitochondria and tubulin microfibers was revealed. Diverse and complex GPER regulation at the mRNA level and protein of estrogen signaling molecules (estrogen receptor α and β; ERα, ERβ and cytochrome P450 aromatase; P450arom) in G-15 Leydig cells was found in relation to age and the experimental system utilized (in vivo and in vitro). Changes in expression patterns of ERs and P450arom, as well as steroid secretion, reflected Leydig cell heterogeneity to estrogen regulation throughout male life including cell physiological status.We show, for the first time, GPER with ERs and P450arom work in tandem to maintain Leydig cell architecture and supervise its steroidogenic function by estrogen during male life. Full set of estrogen signaling molecules, with involvement of GPER, is crucial for proper Leydig cell function where each molecule acts in a specific and/or complementary manner. Further understanding of the mechanisms by which GPER controls Leydig cells with special regard to male age, cell of origin and experimental system used is critical for predicting and preventing testis steroidogenic disorders based on perturbations in estrogen signaling.</jats:p

Gradient chitosan hydrogels modified with graphene derivatives and hydroxyapatite : physiochemical properties and initial cytocompatibility evaluation

In this study, we investigated preparation of gradient chitosan-matrix hydrogels through a novel freezing&ndash;gelling&ndash;thawing method. The influence of three types of graphene family materials (GFM), i.e., graphene oxide (GO), reduced graphene oxide (rGO), and poly(ethylene glycol) grafted graphene oxide (GO-PEG), as well as hydroxyapatite (HAp) on the physicochemical and biological properties of the composite hydrogels was examined in view of their potential applicability as tissue engineering scaffolds. The substrates and the hydrogel samples were thoroughly characterized by X-ray photoelectron spectroscopy, X-ray diffractometry, infrared spectroscopy, digital and scanning electron microscopy, rheological and mechanical analysis, in vitro chemical stability and bioactivity assays, as well as initial cytocompatibility evaluation with human umbilical cord Wharton&rsquo;s jelly mesenchymal stem cells (hUC-MSCs). We followed the green-chemistry approach and avoided toxic cross-linking agents, using instead specific interactions of our polymer matrix with tannic acid, non-toxic physical cross-linker, and graphene derivatives. It was shown that the most promising are the gradient hydrogels modified with GO-PEG and HAp

Multilineage differentiation potential of human dental pulp stem cells : impact of 3D and hypoxic environment on osteogenesis in vitro

Human dental pulp harbours unique stem cell population exhibiting mesenchymal stem/stromal cell (MSC) characteristics. This study aimed to analyse the differentiation potential and other essential functional and morphological features of dental pulp stem cells (DPSCs) in comparison with Wharton&rsquo;s jelly-derived MSCs from the umbilical cord (UC-MSCs), and to evaluate the osteogenic differentiation of DPSCs in 3D culture with a hypoxic microenvironment resembling the stem cell niche. Human DPSCs as well as UC-MSCs were isolated from primary human tissues and were subjected to a series of experiments. We established a multiantigenic profile of DPSCs with CD45&minus;/CD14&minus;/CD34&minus;/CD29+/CD44+/CD73+/CD90+/CD105+/Stro-1+/HLA-DR&minus; (using flow cytometry) and confirmed their tri-lineage osteogenic, chondrogenic, and adipogenic differentiation potential (using qRT-PCR and histochemical staining) in comparison with the UC-MSCs. The results also demonstrated the potency of DPSCs to differentiate into osteoblasts in vitro. Moreover, we showed that the DPSCs exhibit limited cardiomyogenic and endothelial differentiation potential. Decreased proliferation and metabolic activity as well as increased osteogenic differentiation of DPSCs in vitro, attributed to 3D cell encapsulation and low oxygen concentration, were also observed. DPSCs exhibiting elevated osteogenic potential may serve as potential candidates for a cell-based product for advanced therapy, particularly for bone repair. Novel tissue engineering approaches combining DPSCs, 3D biomaterial scaffolds, and other stimulating chemical factors may represent innovative strategies for pro-regenerative therapies