scholarly journals Zn- or Cu-containing CaP-Based Coatings Formed by Micro-Arc Oxidation on Titanium and Ti-40Nb Alloy: Part II—Wettability and Biological Performance

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4366
Author(s):  
Ekaterina G. Komarova ◽  
Yurii P. Sharkeev ◽  
Mariya B. Sedelnikova ◽  
Oleg Prymak ◽  
Matthias Epple ◽  
...  
Keyword(s):  
Surface Energy ◽  
Pure Titanium ◽  
Multipotent Mesenchymal Stromal Cells ◽  
Contact Angles ◽  
Polar Component ◽  
Micro Arc Oxidation ◽  
Main Component ◽  
Biological Performance

This work describes the wettability and biological performance of Zn- and Cu-containing CaP-based coatings prepared by micro-arc oxidation on pure titanium (Ti) and novel Ti-40Nb alloy. Good hydrophilic properties of all the coatings were demonstrated by the low contact angles with liquids, not exceeding 45°. An increase in the applied voltage led to an increase of the coating roughness and porosity, thereby reducing the contact angles to 6° with water and to 17° with glycerol. The free surface energy of 75 ± 3 mJ/m2 for all the coatings were determined. Polar component was calculated as the main component of surface energy, caused by the presence of strong polar PO43− and OH− bonds. In vitro studies showed that low Cu and Zn amounts (~0.4 at.%) in the coatings promoted high motility of human adipose-derived multipotent mesenchymal stromal cells (hAMMSC) on the implant/cell interface and subsequent cell ability to differentiate into osteoblasts. In vivo study demonstrated 100% ectopic bone formation only on the surface of the CaP coating on Ti. The Zn- and Cu-containing CaP coatings on both substrates and the CaP coating on the Ti-40Nb alloy slightly decreased the incidence of ectopic osteogenesis down to 67%. The MAO coatings showed antibacterial efficacy against Staphylococcus aureus and can be arranged as follows: Zn-CaP/Ti > Cu-CaP/TiNb, Zn-CaP/TiNb > Cu-CaP/Ti.

scholarly journals Cationic Substitutions in Hydroxyapatite: Current Status of the Derived Biofunctional Effects and Their In Vitro Interrogation Methods

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2081 ◽  
Author(s):  
Teddy Tite ◽  
Adrian-Claudiu Popa ◽  
Liliana Balescu ◽  
Iuliana Bogdan ◽  
Iuliana Pasuk ◽  
...  
Keyword(s):  
High Performance ◽  
Life Time ◽  
Crystalline Lattice ◽  
Current Status ◽  
Synthesis Methods ◽  
Biological Interactions ◽  
Application Range ◽  
Biological Performance

High-performance bioceramics are required for preventing failure and prolonging the life-time of bone grafting scaffolds and osseous implants. The proper identification and development of materials with extended functionalities addressing socio-economic needs and health problems constitute important and critical steps at the heart of clinical research. Recent findings in the realm of ion-substituted hydroxyapatite (HA) could pave the road towards significant developments in biomedicine, with an emphasis on a new generation of orthopaedic and dentistry applications, since such bioceramics are able to mimic the structural, compositional and mechanical properties of the bone mineral phase. In fact, the fascinating ability of the HA crystalline lattice to allow for the substitution of calcium ions with a plethora of cationic species has been widely explored in the recent period, with consequent modifications of its physical and chemical features, as well as its functional mechanical and in vitro and in vivo biological performance. A comprehensive inventory of the progresses achieved so far is both opportune and of paramount importance, in order to not only gather and summarize information, but to also allow fellow researchers to compare with ease and filter the best solutions for the cation substitution of HA-based materials and enable the development of multi-functional biomedical designs. The review surveys preparation and synthesis methods, pinpoints all the explored cation dopants, and discloses the full application range of substituted HA. Special attention is dedicated to the antimicrobial efficiency spectrum and cytotoxic trade-off concentration values for various cell lines, highlighting new prophylactic routes for the prevention of implant failure. Importantly, the current in vitro biological tests (widely employed to unveil the biological performance of HA-based materials), and their ability to mimic the in vivo biological interactions, are also critically assessed. Future perspectives are discussed, and a series of recommendations are underlined.

scholarly journals ADME/Tox Properties and Biochemical Interactions of Silybin Congeners: In silico Study

2017 ◽  
Vol 12 (2) ◽  
pp. 1934578X1701200 ◽  
Author(s):  
Antonia Diukendjieva ◽  
Merilin Al Sharif ◽  
Petko Alov ◽  
Tania Pencheva ◽  
Ivanka Tsakovska ◽  
...  
Keyword(s):  
In Silico ◽  
Estrogen Receptor Alpha ◽  
Estrogenic Activity ◽  
Qsar Model ◽  
Quantitative Structure Activity Relationship ◽  
Toxic Effects ◽  
Active Constituent ◽  
Main Component

Silymarin, the active constituent of Silybum marianum (milk thistle), and its main component, silybin, are products with well-known hepatoprotective, cytoprotective, antioxidant, and chemopreventative properties. Despite substantial in vitro and in vivo investigations of these flavonolignans, their mechanisms of action and potential toxic effects are not fully defined. In this study we explored important ADME/Tox properties and biochemical interactions of selected flavonolignans using in silico methods. A quantitative structure–activity relationship (QSAR) model based on data from a parallel artificial membrane permeability assay (PAMPA) was used to estimate bioavailability after oral administration. Toxic effects and metabolic transformations were predicted using the knowledge-based expert systems Derek Nexus and Meteor Nexus (Lhasa Ltd). Potential estrogenic activity of the studied silybin congeners was outlined. To address further the stereospecificity of this effect the stereoisomeric forms of silybin were docked into the ligand-binding domain of the human estrogen receptor alpha (ERα) (MOE software, CCG). According to our results both stereoisomers can be accommodated into the ERα active site, but different poses and interactions were observed for silybin A and silybin B.

scholarly journals Echinacea angustifolia DC. Lipophilic Extract Patch for Skin Application: Preparation, In Vitro and In Vivo Studies

Pharmaceutics ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1096
Author(s):  
Dritan Hasa ◽  
Simon Žakelj ◽  
Iztok Grabnar ◽  
Francesco Cilurzo ◽  
Stefano Dall’Acqua ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Skin Permeation ◽  
In Vivo Studies ◽  
Pharmacokinetic Analysis ◽  
Echinacea Angustifolia ◽  
Transdermal Administration ◽  
Lipophilic Extract ◽  
Main Component

Dodeca-2E,4E,8Z,10E/Z-tetraenoic isobutylamide (tetraene) is the main component of Echinacea angustifolia DC. lipophilic extract, the bioavailability and immunomodulatory effect after oral administration in soft gel capsules in healthy volunteers of which we have already demonstrated. In the present work, we assessed the transdermal administration as an alternative route of administration of such an alkamide. The first step, therefore, encompassed the preparation of a drug-in-adhesive patch with an area of 868 mm2 and containing a dose of 0.64 mg of tetraene. In vitro skin permeation studies in Franz-type diffusion chambers resulted in a tetraene flux of (103 ± 10) ng × cm−2 × h−1 with a very good linearity (r = 0.99). The relatively low lag time of just 13 min indicates low binding and the accumulation of tetraene in the skin. Finally, the patch was administered to six healthy volunteers, and the pharmacokinetic analysis was performed by nonlinear mixed effects modelling with soft gel oral capsules serving as the reference formulation. The in vivo results correlated well with the in vitro permeation and indicated an initial burst tetraene absorption from the patch that was in parallel with the zero-order kinetics of absorption. The rate of the latter process was in good agreement with the one estimated in vitro. The tetraene absorption rate was therefore slow and prolonged with time, resulting in a bioavailability of 39% relative to the soft gel capsules and a very flat plasma concentration profile.

scholarly journals Lactoferrin Coating Improves the Antibacterial and Osteogenic Properties of Alkali-Treated Titanium with Nanonetwork Structures

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Derong Yin ◽  
Yonglong Hong ◽  
Luyuan Chen ◽  
Satoshi Komasa ◽  
Yuanyuan Yang ◽  
...  
Keyword(s):  
Dental Implant ◽  
Alkali Treatment ◽  
Pure Titanium ◽  
Antimicrobial Properties ◽  
Biological Properties ◽  
Bacterial Attachment ◽  
Physiological Concentration ◽  
Implant Materials

Titanium and its alloys are the main dental implant materials used at present. The biological properties of pure titanium can be further improved by surface treatment methods. Alkali treatment of pure titanium at room temperature can form nanonetwork structures (TNS) on the surface, which has better osteoinductive ability than pure titanium. However, TNS does not possess antimicrobial properties, and bacterial infection is one of the main reasons for the failure of dental implant therapy. Therefore, it was the focus of our research to endow TNS with certain antimicrobial properties on the premise of maintaining its osteoinductive ability. Because of its excellent broad-spectrum antimicrobial properties and because it promotes osteoblast-like cell growth, lactoferrin (LF) was considered a promising prospect as a surface biological treatment material. In this study, bovine LF of physiological concentration was successfully coated on the surface of TNS to form the TNS-LF composite material. Results from in vitro and in vivo experiments showed that TNS-LF had better osteoinductive ability than TNS. Bacterial attachment and biofilm formation were also significantly decreased on the surface of TNS-LF. Therefore, this study has provided an experimental basis for the development of osteoinduction-antimicrobial composite implant materials for dental applications.

In vitro and in vivo biological performance of collagen-chitosan/silicone membrane bilayer dermal equivalent

2007 ◽  
Vol 18 (11) ◽  
pp. 2185-2191 ◽  
Author(s):  
Lie Ma ◽  
Yanchao Shi ◽  
Yixin Chen ◽  
Haiguang Zhao ◽  
Changyou Gao ◽  
...  
Keyword(s):  
Silicone Membrane ◽  
Membrane Bilayer ◽  
Dermal Equivalent ◽  
Biological Performance

scholarly journals Allogeneic Adipose-Derived Mesenchymal Stromal Cells Ameliorate Experimental Autoimmune Encephalomyelitis by Regulating Self-Reactive T Cell Responses and Dendritic Cell Function

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Per Anderson ◽  
Elena Gonzalez-Rey ◽  
Francisco O’Valle ◽  
Francisco Martin ◽  
F. Javier Oliver ◽  
...  
Keyword(s):  
T Cell ◽  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
Cell Function ◽  
Multipotent Mesenchymal Stromal Cells ◽  
Brain Inflammation ◽  
Inos Inhibitor ◽  
Cox 1

Multipotent mesenchymal stromal cells (MSCs) have emerged as a promising therapy for autoimmune diseases, including multiple sclerosis (MS). Administration of MSCs to MS patients has proven safe with signs of immunomodulation but their therapeutic efficacy remains low. The aim of the current study has been to further characterize the immunomodulatory mechanisms of adipose tissue-derived MSCs (ASCs) in vitro and in vivo using the EAE model of chronic brain inflammation in mice. We found that murine ASCs (mASCs) suppress T cell proliferation in vitro via inducible nitric oxide synthase (iNOS) and cyclooxygenase- (COX-) 1/2 activities. mASCs also prevented the lipopolysaccharide- (LPS-) induced maturation of dendritic cells (DCs) in vitro. The addition of the COX-1/2 inhibitor indomethacin, but not the iNOS inhibitor L-NAME, reversed the block in DC maturation implicating prostaglandin (PG) E2 in this process. In vivo, early administration of murine and human ASCs (hASCs) ameliorated myelin oligodendrocyte protein- (MOG35-55-) induced EAE in C57Bl/6 mice. Mechanistic studies showed that mASCs suppressed the function of autoantigen-specific T cells and also decreased the frequency of activated (CD11c+CD40high and CD11c+TNF-α+) DCs in draining lymph nodes (DLNs). In summary, these data suggest that mASCs reduce EAE severity, in part, through the impairment of DC and T cell function.

scholarly journals Hydroxyapatite-Coated Titanium by Micro-Arc Oxidation and Steam–Hydrothermal Treatment Promotes Osseointegration

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiaojun Wang ◽  
Lina Mei ◽  
Xuesheng Jiang ◽  
Mingchao Jin ◽  
Yan Xu ◽  
...  
Keyword(s):  
Hydrothermal Treatment ◽  
Cell Attachment ◽  
Vascular Endothelial ◽  
Matrix Mineralization ◽  
X Ray ◽  
Micro Arc Oxidation ◽  
Surface Physicochemical Properties ◽  
Endothelial Growth Factor

Titanium (Ti)-based alloys are widely used in tissue regeneration with advantages of improved biocompatibility, high mechanical strength, corrosion resistance, and cell attachment. To obtain bioactive bone–implant interfaces with enhanced osteogenic capacity, various methods have been developed to modify the surface physicochemical properties of bio-inert Ti and Ti alloys. Nano-structured hydroxyapatite (HA) formed by micro-arc oxidation (MAO) is a synthetic material, which could facilitate osteoconductivity, osteoinductivity, and angiogenesis on the Ti surface. In this paper, we applied MAO and steam–hydrothermal treatment (SHT) to produce HA-coated Ti, hereafter called Ti–M–H. The surface morphology of Ti–M–H1 was observed by scanning electron microscopy (SEM), and the element composition and the roughness of Ti–M–H1 were analyzed by energy-dispersive X-ray analysis, an X-ray diffractometer (XRD), and Bruker stylus profiler, demonstrating the deposition of nano-HA particles on Ti surfaces that were composed of Ca, P, Ti, and O. Then, the role of Ti–M–H in osteogenesis and angiogenesis in vitro was evaluated. The data illustrated that Ti–M–H1 showed a good compatibility with osteoblasts (OBs), which promoted adhesion, spreading, and proliferation. Additionally, the secretion of ALP, Col-1, and extracellular matrix mineralization was increased by OBs treated with Ti–M–H1. Ti–M–H1 could stimulate endothelial cells to secrete vascular endothelial growth factor and promote the formation of capillary-like networks. Next, it was revealed that Ti–M–H1 also suppressed inflammation by activating macrophages, while releasing multiple active factors to mediate osteogenesis and angiogenesis. Finally, in vivo results uncovered that Ti–M–H1 facilitated a higher bone-to-implant interface and was more attractive for the dendrites, which promoted osseointegration. In summary, MAO and SHT-treated Ti–M–H1 not only promotes in vitro osteogenesis and angiogenesis but also induces M2 macrophages to regulate the immune environment, which enhances the crosstalk between osteogenesis and angiogenesis and ultimately accelerates the process of osseointegration in vivo.

scholarly journals The pentaglycine bridges ofStaphylococcus aureuspeptidoglycan are essential for cell integrity

2018 ◽  
Author(s):  
João M. Monteiro ◽  
Daniela Münch ◽  
Sérgio R. Filipe ◽  
Tanja Schneider ◽  
Hans-Georg Sahl ◽  
...  
Keyword(s):  
Sharp Decrease ◽  
Bacterial Cells ◽  
Cell Integrity ◽  
Protein Activity ◽  
Membrane Rupture ◽  
Cross Bridge ◽  
Cross Bridges ◽  
Main Component

AbstractBacterial cells are surrounded by cell wall, whose main component is peptidoglycan (PG), a macromolecule that withstands the internal turgor of the cell. PG composition can vary considerably between species. The Gram-positive pathogenStaphylococcus aureuspossesses highly crosslinked PG due to the presence of cross bridges containing five glycines, which are synthesised by the FemXAB protein family. FemX adds the first glycine of the cross bridge, while FemA and FemB add the second and the third, and the fourth and the fifth glycines, respectively. Of these, FemX was reported to be essential. To investigate the essentiality of FemAB, we constructed a conditionalS. aureusmutant of thefemABoperon. Depletion offemABwas lethal, with cells appearing as pseudomulticellular forms that eventually lyse due to extensive membrane rupture. This deleterious effect was mitigated by drastically increasing the osmolarity of the medium, indicating that pentaglycine crosslinks are required forS. aureuscells to withstand internal turgor. Despite the absence of canonical membrane targeting domains, FemA has been shown to localise at the membrane. To study its mechanism of localisation, we constructed mutants in key residues present in the putative transferase pocket and the α6 helix of FemA, possibly involved in tRNA binding. Mutations in the α6 helix led to a sharp decrease in protein activityin vivoandin vitrobut did not impair correct membrane localisation, indicating that FemA activity is not required for localisation. Our data indicates that, contrarily to what was previously thought,S. aureuscells do not survive in the absence of a pentaglycine cross bridge.

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