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Simple Summary: Despite advancements in the treatment of hematological malignancies, disease relapse is still a major concern in the management of acute myeloid leukemia (AML). It is believed that chemotherapeutic resistance in leukemic stem cells is the driving factor behind disease relapse. The role of in vitro 3D models in studying the mechanisms of chemotherapeutic drug resistance in leukemic stem cells is not well-researched. Herein, we review the recent advancements in using 3D in vitro models in studying AML. In addition, we describe their role as potential platforms for understanding mechanisms of resistance and relapse in AML and in identifying and testing therapeutic modalities. The complexity of the bone marrow (BM) microenvironment makes studying hematological malignancies in vitro a challenging task. Three-dimensional cell cultures are being actively studied, particularly due to their ability to serve as a bridge of the gap between 2D cultures and animal models. The role of 3D in vitro models in studying the mechanisms of chemotherapeutic resistance and leukemia stem cells (LSCs) in acute myeloid leukemia (AML) is not well-reviewed. We present an overview of 3D cell models used for studying AML, emphasizing the recent advancements in microenvironment modeling, chemotherapy testing, and resistance. [ABSTRACT FROM AUTHOR]

Nanofibers have attracted great research attention owing to their unique physicochemical characteristics and broad implementation potential. These one dimensional nanostructures are being increasingly applied in biomedical fields such as manufacturing the scaffolding materials for regenerate new tissues owing to their great surface area/to/volume ratio, high porosity by interrelated pore configuration and the suitable surface structure for cell attachment, proliferation, growth, adhesion, viability and differentiation. Nanofibrous scaffolds with porous construction can mimic the extra cellular matrix structure in providing the suitable area for cells in their microenvironment. Fabrication of nanofibrous scaffolds for cell cultivating is an important process for tissue engineering method. After that, implanting the scaffold―cell matrix in human body is a main stage for tissue regeneration. This review will consider important notes about tissue regeneration process briefly, and the novel explorations in manufacturing the nanostructure scaffolds will be reported. [ABSTRACT FROM AUTHOR]

Tissue engineering (TE) has been developed to create functional organs and tissue by combining 3D matrix and cells in vitro. Vascularization and angiogenesis are utmost important for supply of nutrients and oxygen in tissue engineered organs. The present study was performed to isolate and characterize primary endothelial cells (EC) from aorta of alpha 1, 3-enzyme galactosyltransferase knock out (GalT KO) pig, to minimize immune rejection and analyze body immune system for future xenotransplantation studies. Isolation of primary EC from aorta were performed by incubation with dispase for 8-10 min at 37°C. Primary EC were cultured in EC growth medium on different extra cellular matrix (ECM), either collagen or gelation. Primary EC exhibits morphological characteristics and showed positive expressions of EC specific marker proteins i.e. PECAM1, KDR and VWF despite of their ECM surface; however, on collagen based surface they showed increase in mRNA level analyzed by qPCR. Primary EC cultured on collagen were sorted by flow cytometer using KDR marker and cultured as KDR positive cells and KDR negative cells, respectively. KDR positive cells showed dramatically increased in PECAM1 and VWF level as compared to KDR negative cells. Based on the above results, primary EC derived from GalT KO are successfully isolated and survived continuously in culture without becoming overgrown by fibroblast. Therefore, they can be utilize for xeno organ transfer, tissue engineering, and immune rejection study in future.

Surface and mechanical properties of the biomaterials are determinants of cellular responses. In our previous study, star-shaped poly( d,l -Lactide)- b -gelatin (ss-pLG) was reported for possessing improved cellular adhesion and proliferation. Here, we extended our investigation to establish the cellular compatibility of gelatin-grafted PDLLA with respect to mechanical properties of biological tissues. In this view, linear PDLLA- b -gelatin (l-pLG) was synthesized and tissue-level compatibility of 1-pLG and ss-pLG against fibroblasts (L929), myoblasts (C2C12) and preosteoblasts (MG-63) was examined. The cell proliferation of C2C12 was significantly higher within l-pLG scaffolds, whereas L929 showed intensified growth within ss-pLG scaffolds. The difference in cell proliferation may be attributed to the varying mechanical properties of scaffolds; where the stiffness of l-pLG scaffolds was notably higher than ss-pLG scaffolds, most likely due to the variable levels of gelatin grafting on the backbone of PDLLA. Therefore, gelatin grafting can be used to modulate mechanical property of the scaffolds and this study reveals the significance of the matrix stiffness to produce the successful 3D scaffolds for tissue engineering applications. [ABSTRACT FROM AUTHOR]

Ravi Shrivastava, Nathalie Cucuat, Monika Rousse, Thomas Weigand, Pedro Neto, Claire Janicot, Christiane Shrivastava VITROBIO Research Institute, Issoire, France Purpose: Incidence of chronic wounds is constantly rising worldwide, but all currently available treatments are intended either to provide symptomatic relief or to assist cicatrization to some extent, but not to directly stimulate cellular growth. Physiologically, chronic wound healing simply requires cell growth to fill the injured cavity. To grow, our cells need to attach onto a cushion, called extracellular matrix (ECM), secreted by the mother cells and composed of multiple proteins. Recent scientific works prove that the concentration of certain matrix metalloproteinases (MMPs) is extremely high in all chronic wounds and, because of their proteolytic nature, some MMPs completely degrade the ECM, hindering cell attachment and cell growth. The aim of this study was to identify, neutralize, and eliminate these MMPs from the wound surface so as to design an effective treatment for chronic wounds. Methods: Acute and chronic models of human epithelial and fibroblast cells were prepared on a defined ECM cushion in vitro and MMPs were added in the culture medium to identify the MMPs causing ECM disintegration for each cell type. ECM-degrading MMPs were then incubated with selected procyanidin-rich plant extracts (PCDs) and cell growth was reanalyzed. Results: It was observed that: 1) multiple MMPs are involved in cellular matrix destruction; 2) ECM-destroying MMPs are specific with respect to cell type; and 3) specific PCDs may bind and neutralize selected MMPs. Conclusion: Topical application of specific plant PCDs to selectively neutralize ECM-destroying MMPs in acute and chronic wounds represents a novel approach for the treatment of superficial and deep skin wounds. Keywords: extra cellular matrix (ECM), matrix metalloproteinases, procyanidins (PCDs), tannins, ulcers

Tissue engineering (TE) has been developed to create functional organs and tissue by combining 3D matrix and cells in vitro. Vascularization and angiogenesis are utmost important for supply of nutrients and oxygen in tissue engineered organs. The present study was performed to isolate and characterize primary endothelial cells (EC) from aorta of alpha 1, 3-enzyme galactosyltransferase knock out (GalT KO) pig, to minimize immune rejection and analyze body immune system for future xenotransplantation studies. Isolation of primary EC from aorta were performed by incubation with dispase for 8-10 min at 37℃. Primary EC were cultured in EC growth medium on different extra cellular matrix (ECM), either collagen or gelation. Primary EC exhibits morphological characteristics and showed positive expressions of EC specific marker proteins i.e. PECAM1, KDR and VWF despite of their ECM surface; however, on collagen based surface they showed increase in mRNA level analyzed by qPCR. Primary EC cultured on collagen were sorted by flow cytometer using KDR marker and cultured as KDR positive cells and KDR negative cells, respectively. KDR positive cells showed dramatically increased in PECAM1 and VWF level as compared to KDR negative cells. Based on the above results, primary EC derived from GalT KO are successfully isolated and survived continuously in culture without becoming overgrown by fibroblast. Therefore, they can be utilize for xeno organ transfer, tissue engineering, and immune rejection study in future. [ABSTRACT FROM AUTHOR]

Abstract: Formation of metastases negatively impacts the survival prognosis of cancer patients. Globally, if the various steps involved in their formation are relatively well identified, the molecular mechanisms responsible for the emergence of invasive cancer cells are still incompletely resolved. Elucidating what are the mechanisms that allow cancer cells to evade from the tumor is a crucial point since it is the first step of the metastatic potential of a solid tumor. In order to be invasive, cancer cells have to undergo transformations such as down-regulation of cell-cell adhesions, modification of cell-matrix adhesions and acquisition of proteolytic properties. These transformations are accompanied by the capacity to “activate” stromal cells, which may favor the motility of the invasive cells through the extracellular matrix. Since modulation of gap junctional intercellular communication is known to be involved in cancer, we were interested to consider whether these different transformations necessary for the acquisition of invasive phenotype are related with gap junctions and their structural proteins, the connexins. In this review, emerging roles of connexins and gap junctions in the process of tissue invasion are proposed. [Copyright &y& Elsevier]

Abstract: Rare disorders leading to intellectual disability, such as Fragile X syndrome (FXS) alter synaptic plasticity. Ligand identification of orphan nuclear receptors has led to the discovery of many signaling pathways and has revealed a direct link of nuclear receptors with human conditions such as mental retardation and neurodegenerative diseases. PPARγ agonists can act as neuroprotective agents, promoting synaptic plasticity and neurite outgrowth. Therefore, selective PPARγ agonists are good candidates for therapeutic evaluation in intellectual disabilities. Preliminary results suggest that PPARγ agonists such as Pioglitazone, Rosiglitazone and synthetic agonist, GW1929, are used as the therapeutic agent in neurological disorders. These components interact with intracellular transduction signals (e.g. GSK3β, PI3K/Akt, Wnt/β-Catenin, Rac1 and MMP-9). It seems that interaction with these pathways can improve memory recognition in FXS animal models. The present hypothesis consists of enhancing synaptic plasticity that may then rescue the learning and memory in FXS. This will open many new therapeutic avenues for a variety of human diseases. [Copyright &y& Elsevier]

Highlights: [•] Developments in methods for obtaining collagen derived endogenous angioinhibitors. [•] A comprehensive review discussed different purification methods. [•] Sequential developmental methodology from history. [•] Various modified methods to improve higher yields of biologically active collagen proteins. [•] This review would be of broad interest to many protein biologists for purification methods. [Copyright &y& Elsevier]

Abstract: Tissue engineering approach focuses on the regeneration of deficient or damaged tissues of the body. Regeneration of dental tissues is considered as a promising therapeutic approach in dental tissue engineering. Engineering the environment for developing tissues comprises of biomaterials, growth factors, stem cells and regulation of physiological conditions in a spatial and temporal manner. To enhance the structural stability and bioactivity of polymers, a wide variety of nanomaterials are being utilized in dental regenerative medicine. Nanostructured biopolymers in the form of scaffolds, hydrogels, nanofibers, dendrimers, films, etc. and nanostructured bioceramics such as hydroxyapatite, bioactive glass ceramic/bioglass, etc. in the form of nanoparticles, nanocrystals, nanorods, paste, etc. are being exploited in the simultaneous regeneration of hard and soft tissues of the human body. In the dental area, these different forms closely mimic the natural constituents and framework of the dental tissues, namely enamel, dentin and periodontium. Overall this review essentially focuses on the role of polymeric and ceramic nanomaterials in the area of dental tissue engineering, highlighting their specific applications in enamel, dentin and periodontal regeneration. [Copyright &y& Elsevier]

Abstract: The selection, synthesis, modification and shaping of biomaterials are complex tasks within the biomedical field. Human and plant tissues, such as, wood, bone and cartilage are structured at the nanometer level and exhibit a hierarchical structure up to the macroscale. Their morphological similarities enable the exploitation of lignocellulosic materials in the development of nanostructured composites targeting tissue engineering and regeneration. In this review, lignocellulosic materials and their chemical constituents are highlighted as promising alternatives for the development of drug-delivery vehicles and for the engineering or regeneration of bone and cartilage. Special focus is given to the recent developments of lignocellulosic bionanocomposite supports that induce cell attachment and proliferation. Chemical modifications techniques as well as composite processing methodologies that enhance the biomaterial performance are reviewed. It is anticipated the increasing interest in nanocellulose, bacterial cellulose, hemicellulose and lignin from natural resources as added-value biomedical materials in the near future. [Copyright &y& Elsevier]

Exploring the possibility of using zeolites in tissue engineering scaffolds is a potential approach in regenerative medicine because of their biocompatibility and cation exchange ability. A novel method to synthesize formaldehyde crosslinked gelatin/zeolite scaffolds by lyophilisation technique is reported in this paper. AFM images of gelatin solutions obtained before and after the addition of formaldehyde, revealed the coil to helix transformation of gelatin after crosslinking. The pore size of gelatin control scaffold was in the range of 50−750μm while it was greatly reduced to 10−350μm after incorporation of 0.5% zeolites in gelatin matrix, G(0.5%). Micro-CT analysis showed that porosity of G(0.5%) was 81% and the pores were well interconnected. The elemental analysis and crystallinity studies confirmed the presence of zeolites in G(0.5%). Interestingly, contact angle was found to increase from 88.6° to 108° with the increase in concentration of zeolites in gelatin. G(0.5%) showed the highest glass transition temperature (∼37°C) as well as dynamic compression modulus (∼737kPa). Swelling and degradation of scaffolds were tuned by adjusting concentration of zeolites in the composite scaffolds. All these results suggest that they can be further investigated for their application in tissue engineering. [ABSTRACT FROM AUTHOR]

Asthma is characterized by eosinophilic airway inflammation and remodeling of the airway wall. Features of airway remodeling include increased airway smooth muscle (ASM) mass. However, little is known about the interaction between inflammatory eosinophils and ASM cells. In this study, we investigated the effect of eosinophils on ASM cell proliferation. Eosinophils were isolated from peripheral blood of mild asthmatics and non-asthmatic subjects and co-cultured with human primary ASM cells. ASM proliferation was estimated using Ki-67 expression assay. The expression of extracellular matrix (ECM) mRNA in ASM cells was measured using quantitative real-time PCR. The role of eosinophil derived Cysteinyl Leukotrienes (CysLTs) in enhancing ASM proliferation was estimated by measuring the release of leukotrienes from eosinophils upon their direct contact with ASM cells using ELISA. This role was confirmed either by blocking eosinophil-ASM contact or co-culturing them in the presence of leukotrienes antagonist. ASM cells co-cultured with eosinophils, isolated from asthmatics, but not non-asthmatics, had a significantly higher rate of proliferation compared to controls. This increase in ASM proliferation was independent of their release of ECM proteins but dependent upon eosinophils release of CysLTs. Eosinophil-ASM cell to cell contact was required for CysLTs release. Preventing eosinophil contact with ASM cells using anti-adhesion molecules antibodies, or blocking the activity of eosinophil derived CysLTs using montelukast inhibited ASM proliferation. Our results indicated that eosinophils contribute to airway remodeling during asthma by enhancing ASM cell proliferation and hence increasing ASM mass. Direct contact of eosinophils with ASM cells triggers their release of CysLTs which enhance ASM proliferation. Eosinophils, and their binding to ASM cells, constitute a potential therapeutic target to interfere with the series of biological events leading to airway remodeling and Asthma. [ABSTRACT FROM AUTHOR]

Stem cell differentiation is dictated by the dynamic crosstalk between cells and their underlying extracellular matrix. While the importance of matrix degradation mediated by enzymes such as matrix metalloproteinases (MMPs) in the context of cancer invasion is well established, the role of MMPs in stem cell differentiation remains relatively unexplored. Here we address this question by assaying MMP expression and activity during differentiation of mouse embryonic stem cells (mESCs) on mouse embryonic fibroblast (MEF) derived matrices (MEFDMs) of varying stiffness and composition. We show that mESC differentiation into different germ layers is associated with expression of several MMPs including MMP-11, 2, 17, 25 and 9, with MMP-9 detected in cell secreted media. Different extents of softening of the different MEFDMs led to altered integrin expression, activated distinct mechanotransduction and metabolic pathways, and induced expression of germ layer-specific markers. Inhibition of MMP proteolytic activity by the broad spectrum MMP inhibitor GM6001 led to alterations in germ layer commitment of the differentiating mESCs. Together, our results illustrate the effect of MMPs in regulating mESC differentiation on engineered cell derived matrices and establish MEFDMs as suitable substrates for understanding molecular mechanisms regulating stem cell development and for regenerative medicine applications. [ABSTRACT FROM AUTHOR]

Abstract: Curcumin (1, 7-bis (4-hydroxyl-3-methoxyphenyl)-1, 6 heptadiene-3, 5-dione) is a potent natural anti oxidant and anti-inflammatory agent, which mediates its effects mainly by inhibiting the activity of enzymes like cyclooxygenase, lipooxygenases and phospholipase A2. Here we examined the possibility of curcumin affecting the production of matrix metalloproteinases (MMPs) by peripheral blood mononuclear cells (PBMCs), which play an important role in inflammation. Zymographic analysis and ELISA showed that curcumin significantly inhibited the activity and level of MMPs produced by PBMCs isolated from human and inflammation-induced rabbit in a concentration dependent manner. The administration of curcumin to inflammation-induced rabbits also caused downregulation of MMP-9. Kinetic analysis showed that the effect of curcumin was a delayed one indicating inhibition of de novo protein synthesis. RT-PCR and immunoblot analysis showed inhibition of the production of MMP-9 mRNA and protein respectively by human PBMCs, which were activated in vitro by Artocarpus Lakoocha agglutinin (ALA) lectin. EMSA and super shift showed activation of classical NFκB in in vitro activated PBMCs and treatment with curcumin inhibited activation of NFκB. Immunoblot analysis suggested that ALA-induced activation of NFκB leading to the upregulation of MMP-9 was due to the degradation of IκB-α. Curcumin inhibited the degradation of IκB-α, which inhibited the ALA mediated activation of NFκB and upregulation of MMP-9. These results indicated that anti-inflammatory effect of curcumin also involves inhibition of the production of MMP-9 in PBMCs. [Copyright &y& Elsevier]

Abstract: Cigarette smoking has been established as a major risk factor for atherosclerosis and also for lung cancer. Nicotine is an active substance present in tobacco. We have analyzed the effect of hesperidin, a bioflavonoid on nicotine induced toxicity. Antioxidant status and expression of MMPs (Matrix metalloproteinases) were analyzed to monitor the protective effect of hesperidin against nicotine toxicity. Our result demonstrated that nicotine significantly up regulates the expression of MMPs and depletes the antioxidant status. On treatment with hesperidin we found the down regulation of expression of MMPs and enhancement in antioxidant status. Hence it could be developed as a drug against tobacco related disease in near future. [Copyright &y& Elsevier]

Research on prostheses for repairing abdominal wall defects has progressed through past decades for developing an ideal prosthesis. The study was designed to compare different extracellular matrix (ECM) derived biological prostheses as alternate to conventional synthetic polymeric prostheses for the repair of full thickness abdominal wall defects. Five biological scaffolds derived from bovine diaphragm, bovine aorta, bovine gall bladder, porcine gall bladder, and rabbit skin were prepared and screened for their in vitro biocompatibility. Decellularized ECMs were subjected to various biocompatibility analyses, namely, water absorption potential, matrix degradation analysis, biomechanical testing, and cytocompatibility analysis. Though the rabbit skin displayed maximum biomechanical strength, due to its rapid degradation, it failed to fulfill the criteria of an ideal prosthesis. ECMs derived from bovine diaphragm and aorta were found to be superior than others based upon hydration and matrix degradation analysis, with best scores for bovine diaphragm followed by bovine aorta. The bovine diaphragm and aorta also displayed sufficient biomechanical strength, with diaphragm being the second highest (next to rabbit skin), in biomechanical strength followed by aorta. None of the biological prosthesis revealed any cytotoxicity. Thus, bovine diaphragm and aorta derived ECM fulfill the necessary criteria for their use as biological prosthesis. Because these prostheses are biocompatible, apart from their low cost, ease of availability, and simple preparation, they present a potential alternative to synthetic prosthesis for repair of abdominal wall defects, especially in veterinary patients., (© 2020 John Wiley & Sons, Ltd.)

Cancer Stem Cells (CSC) generally constitute a minor cellular population within tumors that exhibits some capacities of normal Stem Cells (SC). The existence of CSC, able to self-renew and differentiate, influences central aspects of tumor biology, in part because they can continue tumor growth, give rise to metastasis, and acquire drug and radioresistance, which open new avenues for therapeutics. It is well known that SC constantly interacts with their niche, which includes mesenchymal cells, extracellular ligands, and the Extra Cellular Matrix (ECM). These interactions regularly lead to homeostasis and maintenance of SC characteristics. However, the exact participation of each of these components for CSC maintenance is not clear, as they appear to be context- or cell-specific. In the recent past, surface cellular markers have been fundamental molecular tools for identifying CSC and distinguishing them from other tumor cells. Importantly, some of these cellular markers have been shown to possess functional roles that affect central aspects of CSC. Likewise, some of these markers can participate in regulating the interaction of CSC with their niche, particularly the ECM. We focused this review on the molecular mechanisms of surface cellular markers commonly employed to identify CSC, highlighting the signaling pathways and mechanisms involved in CSC-ECM interactions, through each of the cellular markers commonly used in the study of CSC, such as CD44, CD133, CD49f, CD24, CXCR4, and LGR5. Their presence does not necessarily implicate them in CSC biology., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)