scholarly journals Dolomite-Foamed Bioactive Silicate Scaffolds for Bone Tissue Repair

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 628 ◽  
Author(s):  
Elisa Fiume ◽  
Dilshat Tulyaganov ◽  
Graziano Ubertalli ◽  
Enrica Verné ◽  
Francesco Baino
Keyword(s):  
Three Dimensional ◽  
Bone Grafts ◽  
Structural Features ◽  
Tissue Growth ◽  
Bioactive Glasses ◽  
Easy Method ◽  
Wide Range ◽  
Minimum Requirements ◽  
Manufacturing Techniques

The use of three-dimensional (3D) scaffolds is recognized worldwide as a valuable biomedical approach for promoting tissue regeneration in critical-size bone defects. Over the last 50 years, bioactive glasses have been intensively investigated in a wide range of different clinical applications, from orthopedics to soft tissue healing. Bioactive glasses exhibit the unique capability to chemically bond to the host tissue and, furthermore, their processing versatility makes them very appealing due to the availability of different manufacturing techniques for the production of porous and interconnected synthetic bone grafts able to support new tissue growth over the whole duration of the treatment. As a novel contribution to the broad field of scaffold manufacturing, we report here an effective and relatively easy method to produce silicate glass-derived scaffolds by using, for the first time in the biomedical field, dolomite powder as a foaming agent for the formation of 3D bone-like porous structures. Morphological/structural features, crystallization behavior, and in vitro bioactivity in a simulated body fluid (SBF) were investigated. All the tested scaffolds were found to fulfil the minimum requirements that a scaffold for osseous repair should exhibit, including porosity (65–83 vol.%) and compressive strength (1.3–3.9 MPa) comparable to those of cancellous bone, as well as hydroxyapatite-forming ability (bioactivity). This study proves the suitability of a dolomite-foaming method for the production of potentially suitable bone grafts based on bioactive glass systems.

scholarly journals The Emerging Role of Decellularized Plant-Based Scaffolds as a New Biomaterial

2021 ◽  
Vol 22 (22) ◽  
pp. 12347
Author(s):  
Ashlee F. Harris ◽  
Jerome Lacombe ◽  
Frederic Zenhausern
Keyword(s):  
Mechanical Properties ◽  
Fruits And Vegetables ◽  
Low Cost ◽  
Three Dimensional ◽  
Structural Features ◽  
Cellular Models ◽  
Current State ◽  
Wide Range ◽  
Future Challenges

The decellularization of plant-based biomaterials to generate tissue-engineered substitutes or in vitro cellular models has significantly increased in recent years. These vegetal tissues can be sourced from plant leaves and stems or fruits and vegetables, making them a low-cost, accessible, and sustainable resource from which to generate three-dimensional scaffolds. Each construct is distinct, representing a wide range of architectural and mechanical properties as well as innate vasculature networks. Based on the rapid rise in interest, this review aims to detail the current state of the art and presents the future challenges and perspectives of these unique biomaterials. First, we consider the different existing decellularization techniques, including chemical, detergent-free, enzymatic, and supercritical fluid approaches that are used to generate such scaffolds and examine how these protocols can be selected based on plant cellularity. We next examine strategies for cell seeding onto the plant-derived constructs and the importance of the different functionalization methods used to assist in cell adhesion and promote cell viability. Finally, we discuss how their structural features, such as inherent vasculature, porosity, morphology, and mechanical properties (i.e., stiffness, elasticity, etc.) position plant-based scaffolds as a unique biomaterial and drive their use for specific downstream applications. The main challenges in the field are presented throughout the discussion, and future directions are proposed to help improve the development and use of vegetal constructs in biomedical research.

scholarly journals Mesoporous Silica Nanoparticles and Mesoporous Bioactive Glasses for Wound Management: From Skin Regeneration to Cancer Therapy

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3337
Author(s):  
Sara Hooshmand ◽  
Sahar Mollazadeh ◽  
Negar Akrami ◽  
Mehrnoosh Ghanad ◽  
Ahmed El-Fiqi ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Mesoporous Silica Nanoparticles ◽  
Skin Regeneration ◽  
Bioactive Molecules ◽  
Wound Management ◽  
Bioactive Glasses ◽  
Wide Range

Exploring new therapies for managing skin wounds is under progress and, in this regard, mesoporous silica nanoparticles (MSNs) and mesoporous bioactive glasses (MBGs) offer great opportunities in treating acute, chronic, and malignant wounds. In general, therapeutic effectiveness of both MSNs and MBGs in different formulations (fine powder, fibers, composites etc.) has been proved over all the four stages of normal wound healing including hemostasis, inflammation, proliferation, and remodeling. The main merits of these porous substances can be summarized as their excellent biocompatibility and the ability of loading and delivering a wide range of both hydrophobic and hydrophilic bioactive molecules and chemicals. In addition, doping with inorganic elements (e.g., Cu, Ga, and Ta) into MSNs and MBGs structure is a feasible and practical approach to prepare customized materials for improved skin regeneration. Nowadays, MSNs and MBGs could be utilized in the concept of targeted therapy of skin malignancies (e.g., melanoma) by grafting of specific ligands. Since potential effects of various parameters including the chemical composition, particle size/morphology, textural properties, and surface chemistry should be comprehensively determined via cellular in vitro and in vivo assays, it seems still too early to draw a conclusion on ultimate efficacy of MSNs and MBGs in skin regeneration. In this regard, there are some concerns over the final fate of MSNs and MBGs in the wound site plus optimal dosages for achieving the best outcomes that deserve careful investigation in the future.

Mineralized Nanofibers for Bone Tissue Engineering

2018 ◽  
pp. 461-475 ◽  
Author(s):  
Ozan Karaman
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Regeneration ◽  
Bone Tissue ◽  
Three Dimensional ◽  
Bone Grafts ◽  
Tissue Engineering Scaffolds ◽  
Promising Alternative ◽  
Biomimetic Scaffolds

The limitation of orthopedic fractures and large bone defects treatments has brought the focus on fabricating bone grafts that could enhance ostegenesis and vascularization in-vitro. Developing biomimetic materials such as mineralized nanofibers that can provide three-dimensional templates of the natural bone extracellular-matrix is one of the most promising alternative for bone regeneration. Understanding the interactions between the structure of the scaffolds and cells and therefore the control cellular pathways are critical for developing functional bone grafts. In order to enhance bone regeneration, the engineered scaffold needs to mimic the characteristics of composite bone ECM. This chapter reviews the fabrication of and fabrication techniques for fabricating biomimetic bone tissue engineering scaffolds. In addition, the chapter covers design criteria for developing the scaffolds and examples of enhanced osteogenic differentiation outcomes by fabricating biomimetic scaffolds.

scholarly journals Membrane Protein Complex ExbB4-ExbD1-TonB1from Escherichia coli Demonstrates Conformational Plasticity

2015 ◽  
Vol 197 (11) ◽  
pp. 1873-1885 ◽  
Author(s):  
Aleksandr Sverzhinsky ◽  
Jacqueline W. Chung ◽  
Justin C. Deme ◽  
Lucien Fabre ◽  
Kristian T. Levey ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Iron Acquisition ◽  
Proton Translocation ◽  
Three Dimensional ◽  
Structural Data ◽  
Structural Features ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Content Type

ABSTRACTIron acquisition at the outer membrane (OM) of Gram-negative bacteria is powered by the proton motive force (PMF) of the cytoplasmic membrane (CM), harnessed by the CM-embedded complex of ExbB, ExbD, and TonB. Its stoichiometry, ensemble structural features, and mechanism of action are unknown. By panning combinatorial phage libraries, periplasmic regions of dimerization between ExbD and TonB were predicted. Using overexpression of full-length His6-taggedexbB-exbDand S-taggedtonB, we purified detergent-solubilized complexes of ExbB-ExbD-TonB fromEscherichia coli. Protein-detergent complexes of ∼230 kDa with a hydrodynamic radius of ∼6.0 nm were similar to previously purified ExbB4-ExbD2complexes. Significantly, they differed in electronegativity by native agarose gel electrophoresis. The stoichiometry was determined to be ExbB4-ExbD1-TonB1. Single-particle electron microscopy agrees with this stoichiometry. Two-dimensional averaging supported the phage display predictions, showing two forms of ExbD-TonB periplasmic heterodimerization: extensive and distal. Three-dimensional (3D) particle classification showed three representative conformations of ExbB4-ExbD1-TonB1. Based on our structural data, we propose a model in which ExbD shuttles a proton across the CM via an ExbB interprotein rearrangement. Proton translocation would be coupled to ExbD-mediated collapse of extended TonB in complex with ligand-loaded receptors in the OM, followed by repositioning of TonB through extensive dimerization with ExbD. Here we present the first report for purification of the ExbB-ExbD-TonB complex, molar ratios within the complex (4:1:1), and structural biology that provides insights into 3D organization.IMPORTANCEReceptors in the OM of Gram-negative bacteria allow entry of iron-bound siderophores that are necessary for pathogenicity. Numerous iron-acquisition strategies rely upon a ubiquitous and unique protein for energization: TonB. Complexed with ExbB and ExbD, the Ton system links the PMF to OM transport. Blocking iron uptake by targeting a vital nanomachine holds promise in therapeutics. Despite much research, the stoichiometry, structural arrangement, and molecular mechanism of the CM-embedded ExbB-ExbD-TonB complex remain unreported. Here we demonstratein vitroevidence of ExbB4-ExbD1-TonB1complexes. Using 3D EM, we reconstructed the complex in three conformational states that show variable ExbD-TonB heterodimerization. Our structural observations form the basis of a model for TonB-mediated iron acquisition.

Vascularized Cardiac Spheroids as Novel 3D in vitro Models to Study Cardiac Fibrosis

2017 ◽  
Vol 204 (3-4) ◽  
pp. 191-198 ◽  
Author(s):  
Gemma A. Figtree ◽  
Kristen J. Bubb ◽  
Owen Tang ◽  
Eddy Kizana ◽  
Carmine Gentile
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Cardiac Fibrosis ◽  
Transforming Growth Factor ◽  
Three Dimensional ◽  
In Vitro Models ◽  
Tissue Growth ◽  
Cardiovascular Research

Spheroid cultures are among the most explored cellular biomaterials used in cardiovascular research, due to their improved integration of biochemical and physiological features of the heart in a defined architectural three-dimensional microenvironment when compared to monolayer cultures. To further explore the potential use of spheroid cultures for research, we engineered a novel in vitro model of the heart with vascularized cardiac spheroids (VCSs), by coculturing cardiac myocytes, endothelial cells, and fibroblasts isolated from dissociated rat neonatal hearts (aged 1-3 days) in hanging drop cultures. To evaluate the validity of VCSs in recapitulating pathophysiological processes typical of the in vivo heart, such as cardiac fibrosis, we then treated VCSs with transforming growth factor beta 1 (TGFβ1), a known profibrotic agent. Our mRNA analysis demonstrated that TGFβ1-treated VCSs present elevated levels of expression of connective tissue growth factor, fibronectin, and TGFβ1 when compared to control cultures. We demonstrated a dramatic increase in collagen deposition following TGFβ1 treatment in VCSs in the PicroSirius Red-stained sections. Doxorubicin, a renowned cardiotoxic and profibrotic agent, triggered apoptosis and disrupted vascular networks in VCSs. Taken together, our findings demonstrate that VCSs are a valid model for the study of the mechanisms involved in cardiac fibrosis, with the potential to be used to investigate novel mechanisms and therapeutics for treating and preventing cardiac fibrosis in vitro.

scholarly journals Multi-layer Scaffolds of Poly(caprolactone), Poly(glycerol sebacate) and Bioactive Glasses Manufactured by Combined 3D Printing and Electrospinning

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 626 ◽  
Author(s):  
Adja B. R. Touré ◽  
Elisa Mele ◽  
Jamieson K. Christie
Keyword(s):  
3D Printing ◽  
Three Dimensional ◽  
Bioactive Glasses ◽  
Multi Scale ◽  
Potential Applications ◽  
3D Printed ◽  
Excellent Adhesion ◽  
Poly Caprolactone ◽  
Hydrolysis Of

Three-dimensional (3D) printing has been combined with electrospinning to manufacture multi-layered polymer/glass scaffolds that possess multi-scale porosity, are mechanically robust, release bioactive compounds, degrade at a controlled rate and are biocompatible. Fibrous mats of poly (caprolactone) (PCL) and poly (glycerol sebacate) (PGS) have been directly electrospun on one side of 3D-printed grids of PCL-PGS blends containing bioactive glasses (BGs). The excellent adhesion between layers has resulted in composite scaffolds with a Young’s modulus of 240–310 MPa, higher than that of 3D-printed grids (125–280 MPa, without the electrospun layer). The scaffolds degraded in vitro by releasing PGS and BGs, reaching a weight loss of ~14% after 56 days of incubation. Although the hydrolysis of PGS resulted in the acidification of the buffer medium (to a pH of 5.3–5.4), the release of alkaline ions from the BGs balanced that out and brought the pH back to 6.0. Cytotoxicity tests performed on fibroblasts showed that the PCL-PGS-BGs constructs were biocompatible, with cell viability of above 125% at day 2. This study demonstrates the fabrication of systems with engineered properties by the synergy of diverse technologies and materials (organic and inorganic) for potential applications in tendon and ligament tissue engineering.

scholarly journals 3D Titania Nanofiber-Like Webs Induced by Plasma Ionization: A New Direction for Bioreactivity and Osteoinductivity Enhancement of Biomaterials

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Mohammad-Hossein Beigi ◽  
Naghmeh Safaie ◽  
Mohammad-Hossein Nasr-Esfahani ◽  
Amirkianoosh Kiani
Keyword(s):  
Colorimetric Method ◽  
Three Dimensional ◽  
Picosecond Laser ◽  
Laser Pulses ◽  
Ambient Air ◽  
Analytical Form ◽  
Ion Release ◽  
Characterization Methods ◽  
Wide Range

AbstractIn this study, we describe the formation method of web-like three-dimensional (3-D) titania nanofibrous structures coated on transparent substrate via a high intensity laser induced reverse transfer (HILIRT) process. First, we demonstrate the mechanism of ablation and deposition of Ti on the glass substrates using multiple picosecond laser pulses at ambient air in an explicit analytical form and compare the theoretical results with the experimental results of generated nanofibers. We then examine the performance of the developed glass samples coated by titania nanofibrous structures at varied laser pulse durations by electron microscopy and characterization methods. We follow this by exploring the response of human bone-derived mesenchymal stem cells (BMSCs) with the specimens, using a wide range of in-vitro analyses including MTS assay (colorimetric method for assessing cell metabolic activity), immunocytochemistry, mineralization, ion release examination, gene expression analysis, and protein adsorption and absorption analysis. Our results from the quantitative and qualitative analyses show a significant biocompatibility improvement in the laser treated samples compared to untreated substrates. By decreasing the pulse duration, more titania nanofibers with denser structures can be generated during the HILIRT technique. The findings also suggest that the density of nanostructures and concentration of coated nanofibers play critical roles in the bioreactivity properties of the treated samples, which results in early osteogenic differentiation of BMSCs.

scholarly journals An Interpenetrating Alginate/Gelatin Network for Three-Dimensional (3D) Cell Cultures and Organ Bioprinting

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 756 ◽  
Author(s):  
Qiuhong Chen ◽  
Xiaohong Tian ◽  
Jun Fan ◽  
Hao Tong ◽  
Qiang Ao ◽  
...  
Keyword(s):  
Cell Cultures ◽  
Structural Integrity ◽  
Polymer Network ◽  
Three Dimensional ◽  
Biochemical Properties ◽  
Interpenetrating Polymer Network ◽  
3D Cell Cultures ◽  
Wide Range ◽  
The Individual

Crosslinking is an effective way to improve the physiochemical and biochemical properties of hydrogels. In this study, we describe an interpenetrating polymer network (IPN) of alginate/gelatin hydrogels (i.e., A-G-IPN) in which cells can be encapsulated for in vitro three-dimensional (3D) cultures and organ bioprinting. A double crosslinking model, i.e., using Ca2+ to crosslink alginate molecules and transglutaminase (TG) to crosslink gelatin molecules, is exploited to improve the physiochemical, such as water holding capacity, hardness and structural integrity, and biochemical properties, such as cytocompatibility, of the alginate/gelatin hydrogels. For the sake of convenience, the individual ionic (i.e., only treatment with Ca2+) or enzymatic (i.e., only treatment with TG) crosslinked alginate/gelatin hydrogels are referred as alginate-semi-IPN (i.e., A-semi-IPN) or gelatin-semi-IPN (i.e., G-semi-IPN), respectively. Tunable physiochemical and biochemical properties of the hydrogels have been obtained by changing the crosslinking sequences and polymer concentrations. Cytocompatibilities of the obtained hydrogels are evaluated through in vitro 3D cell cultures and bioprinting. The double crosslinked A-G-IPN hydrogel is a promising candidate for a wide range of biomedical applications, including bioartificial organ manufacturing, high-throughput drug screening, and pathological mechanism analyses.

scholarly journals Osteogenic Effect of ZnO-Mesoporous Glasses Loaded with Osteostatin

Nanomaterials ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 592 ◽  
Author(s):  
Rebeca Pérez ◽  
Sandra Sanchez-Salcedo ◽  
Daniel Lozano ◽  
Clara Heras ◽  
Pedro Esbrit ◽  
...  
Keyword(s):  
Bone Growth ◽  
Textural Properties ◽  
New Bone Formation ◽  
Bioactive Glasses ◽  
Bioactive Materials ◽  
Parathyroid Hormone Related Protein ◽  
Wide Range ◽  
Before And After ◽  
Osteogenic Effect

Mesoporous Bioactive Glasses (MBGs) are a family of bioceramics widely investigated for their putative clinical use as scaffolds for bone regeneration. Their outstanding textural properties allow for high bioactivity when compared with other bioactive materials. Moreover, their great pore volumes allow these glasses to be loaded with a wide range of biomolecules to stimulate new bone formation. In this study, an MBG with a composition, in mol%, of 80% SiO2–15% CaO–5% P2O5 (Blank, BL) was compared with two analogous glasses containing 4% and 5% of ZnO (4ZN and 5ZN) before and after impregnation with osteostatin, a C-terminal peptide from a parathyroid hormone-related protein (PTHrP107-111). Zn2+ ions were included in the glass for their bone growth stimulator properties, whereas osteostatin was added for its osteogenic properties. Glasses were characterized, and their cytocompatibility investigated, in pre-osteoblastic MC3T3-E1 cell cultures. The simultaneous additions of osteostatin and Zn2+ ions provoked enhanced MC3T3-E1 cell viability and a higher differentiation capacity, compared with either raw BL or MBGs supplemented only with osteostatin or Zn2+. These in vitro results show that osteostatin enhances the osteogenic effect of Zn2+-enriched glasses, suggesting the potential of this combined approach in bone tissue engineering applications.

Identification of an MIP-1α–binding heparan sulfate oligosaccharide that supports long-term in vitro maintenance of human LTC-ICs

Blood ◽  
2003 ◽  
Vol 101 (6) ◽  
pp. 2243-2245 ◽  
Author(s):  
Sally E. Stringer ◽  
Matthew S. Nelson ◽  
Pankaj Gupta
Keyword(s):  
Protein Binding ◽  
Heparan Sulfate ◽  
Size Structure ◽  
Structural Features ◽  
Minimum Size ◽  
Binding Ability ◽  
Inflammatory Protein ◽  
Wide Range

We previously showed that heparan sulfate (HS) is required for in vitro cytokine + chemokine-mediated maintenance of primitive human hematopoietic progenitors. However, HS preparations are mixtures of polysaccharide chains of varying size, structure, and protein-binding abilities. Therefore, we examined whether the long-term culture-initiating cells (LTC-IC) supportive capability of HS is attributable to an oligosaccharide of defined length and protein-binding ability. Oligosaccharides of a wide range of sizes were prepared, and their capability to support human marrow LTC-IC maintenance in the presence of low-dose cytokines and a single chemokine, macrophage inflammatory protein-1α (MIP-1α), was examined. LTC-IC supportive capability of HS oligosaccharides correlated directly with size and MIP-1α binding ability. A specific MIP-1α-binding HS oligosaccharide preparation of Mr 10 kDa that optimally supported LTC-IC maintenance was identified. This oligosaccharide had the structure required for MIP-1α binding, which we have recently described. The present study defines the minimum size and structural features of LTC-IC supportive HS.

Sign in / Sign up

Export Citation Format

Share Document