scholarly journals Assessment of the Effects of Si Addition to a New TiMoZrTa System

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7610
Author(s):  
Mihaela-Claudia Spataru ◽  
Florina Daniela Cojocaru ◽  
Andrei Victor Sandu ◽  
Carmen Solcan ◽  
Ioana Alexandra Duceac ◽  
...  

Ti-based alloys are widely used in medical applications. When implant devices are used to reconstruct disordered bone, prevent bone resorption and enhance good bone remodeling, the Young’s modulus of implants should be close to that of the bone. To satisfy this requirement, many titanium alloys with different biocompatible elements (Zr, Ta, Mo, Si etc.) interact well with adjacent bone tissues, promoting an adequate osseointegration. Four new different alloys were obtained and investigated regarding their microstructure, mechanical, chemical and biological behavior (in vitro and in vivo evaluation), as follows: Ti20Mo7Zr15Ta, Ti20Mo7Zr15Ta0.5Si, Ti20Mo7Zr15Ta0.75Si and Ti20Mo7Zr15TaSi. 60 days after implantation, both in control and experimental rabbits, at the level of implantation gap and into the periimplant area were found the mesenchymal stem cells which differentiate into osteoblasts, then osteocytes and osteoclasts which are involved in the new bone synthesis and remodeling, the periimplant fibrous capsule being continued by newly spongy bone tissue, showing a good osseointegration of alloys. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay confirmed the in vitro cytocompatibility of the prepared alloys.

Biomedicines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1632
Author(s):  
Chiung-Chyi Shen ◽  
Shan-Hui Hsu ◽  
Kai-Bo Chang ◽  
Chun-An Yeh ◽  
Hsiang-Chun Chang ◽  
...  

In this study, polyethylene glycol (PEG) with hydroxyapatite (HA), with the incorporation of physical gold nanoparticles (AuNPs), was created and equipped through a surface coating technique in order to form PEG-HA-AuNP nanocomposites. The surface morphology and chemical composition were characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), UV–Vis spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and contact angle assessment. The effects of PEG-HA-AuNP nanocomposites on the biocompatibility and biological activity of MC3T3-E1 osteoblast cells, endothelial cells (EC), macrophages (RAW 264.7), and human mesenchymal stem cells (MSCs), as well as the guiding of osteogenic differentiation, were estimated through the use of an in vitro assay. Moreover, the anti-inflammatory, biocompatibility, and endothelialization capacities were further assessed through in vivo evaluation. The PEG-HA-AuNP nanocomposites showed superior biological properties and biocompatibility capacity for cell behavior in both MC3T3-E1 cells and MSCs. These biological events surrounding the cells could be associated with the activation of adhesion, proliferation, migration, and differentiation processes on the PEG-HA-AuNP nanocomposites. Indeed, the induction of the osteogenic differentiation of MSCs by PEG-HA-AuNP nanocomposites and enhanced mineralization activity were also evidenced in this study. Moreover, from the in vivo assay, we further found that PEG-HA-AuNP nanocomposites not only facilitate the anti-immune response, as well as reducing CD86 expression, but also facilitate the endothelialization ability, as well as promoting CD31 expression, when implanted into rats subcutaneously for a period of 1 month. The current research illustrates the potential of PEG-HA-AuNP nanocomposites when used in combination with MSCs for the regeneration of bone tissue, with their nanotopography being employed as an applicable surface modification approach for the fabrication of biomaterials.


2016 ◽  
Vol 33 ◽  
pp. 275-282 ◽  
Author(s):  
Juan L. Paris ◽  
Paz de la Torre ◽  
Miguel Manzano ◽  
M. Victoria Cabañas ◽  
Ana I. Flores ◽  
...  

2019 ◽  
Vol 98 (9) ◽  
pp. 350-355

Introduction: There is evidence that mesenchymal stem cells (MSCs) could trans-differentiate into the liver cells in vitro and in vivo and thus may be used as an unfailing source for stem cell therapy of liver disease. Combination of MSCs (with or without their differentiation in vitro) and minimally invasive procedures as laparoscopy or Natural Orifice Transluminal Endoscopic Surgery (NOTES) represents a chance for many patients waiting for liver transplantation in vain. Methods: Over 30 millions of autologous MSCs at passage 3 were transplanted via the portal vein in an eight months old miniature pig. The deposition of transplanted cells in liver parenchyma was evaluated histologically and the trans-differential potential of CM-DiI labeled cells was assessed by expression of pig albumin using immunofluorescence. Results: Three weeks after transplantation we detected the labeled cells (solitary, small clusters) in all 10 samples (2 samples from each lobe) but no diffuse distribution in the samples. The localization of CM-DiI+ cells was predominantly observed around the portal triads. We also detected the localization of albumin signal in CM-DiI labeled cells. Conclusion: The study results showed that the autologous MSCs (without additional hepatic differentiation in vitro) transplantation through the portal vein led to successful infiltration of intact miniature pig liver parenchyma with detectable in vivo trans-differentiation. NOTES as well as other newly developed surgical approaches in combination with cell therapy seem to be very promising for the treatment of hepatic diseases in near future.


Author(s):  
Bruna O. S. Câmara ◽  
Bruno M. Bertassoli ◽  
Natália M. Ocarino ◽  
Rogéria Serakides

The use of stem cells in cell therapies has shown promising results in the treatment of several diseases, including diabetes mellitus, in both humans and animals. Mesenchymal stem cells (MSCs) can be isolated from various locations, including bone marrow, adipose tissues, synovia, muscles, dental pulp, umbilical cords, and the placenta. In vitro, by manipulating the composition of the culture medium or transfection, MSCs can differentiate into several cell lineages, including insulin-producing cells (IPCs). Unlike osteogenic, chondrogenic, and adipogenic differentiation, for which the culture medium and time are similar between studies, studies involving the induction of MSC differentiation in IPCs differ greatly. This divergence is usually evident in relation to the differentiation technique used, the composition of the culture medium, the cultivation time, which can vary from a few hours to several months, and the number of steps to complete differentiation. However, although there is no “gold standard” differentiation medium composition, most prominent studies mention the use of nicotinamide, exedin-4, ß-mercaptoethanol, fibroblast growth factor b (FGFb), and glucose in the culture medium to promote the differentiation of MSCs into IPCs. Therefore, the purpose of this review is to investigate the stages of MSC differentiation into IPCs both in vivo and in vitro, as well as address differentiation techniques and molecular actions and mechanisms by which some substances, such as nicotinamide, exedin-4, ßmercaptoethanol, FGFb, and glucose, participate in the differentiation process.


Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 781 ◽  
Author(s):  
Paula E. Florian ◽  
Liviu Duta ◽  
Valentina Grumezescu ◽  
Gianina Popescu-Pelin ◽  
Andrei C. Popescu ◽  
...  

This study is focused on the adhesion and differentiation of the human primary mesenchymal stem cells (hMSC) to osteoblasts lineage on biological-derived hydroxyapatite (BHA) and lithium-doped BHA (BHA:LiP) coatings synthesized by Pulsed Laser Deposition. An optimum adhesion of the cells on the surface of BHA:LiP coatings compared to control (uncoated Ti) was demonstrated using immunofluorescence labelling of actin and vinculin, two proteins involved in the initiation of the cell adhesion process. BHA:LiP coatings were also found to favor the differentiation of the hMSC towards an osteoblastic phenotype in the presence of osteoinductive medium, as revealed by the evaluation of osteoblast-specific markers, osteocalcin and alkaline phosphatase. Numerous nodules of mineralization secreted from osteoblast cells grown on the surface of BHA:LiP coatings and a 3D network-like organization of cells interconnected into the extracellular matrix were evidenced. These findings highlight the good biocompatibility of the BHA coatings and demonstrate that the use of lithium as a doping agent results in an enhanced osteointegration potential of the synthesized biomaterials, which might therefore represent viable candidates for future in vivo applications.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Pegah Nammian ◽  
Seyedeh-Leili Asadi-Yousefabad ◽  
Sajad Daneshi ◽  
Mohammad Hasan Sheikhha ◽  
Seyed Mohammad Bagher Tabei ◽  
...  

Abstract Introduction Critical limb ischemia (CLI) is the most advanced form of peripheral arterial disease (PAD) characterized by ischemic rest pain and non-healing ulcers. Currently, the standard therapy for CLI is the surgical reconstruction and endovascular therapy or limb amputation for patients with no treatment options. Neovasculogenesis induced by mesenchymal stem cells (MSCs) therapy is a promising approach to improve CLI. Owing to their angiogenic and immunomodulatory potential, MSCs are perfect candidates for the treatment of CLI. The purpose of this study was to determine and compare the in vitro and in vivo effects of allogeneic bone marrow mesenchymal stem cells (BM-MSCs) and adipose tissue mesenchymal stem cells (AT-MSCs) on CLI treatment. Methods For the first step, BM-MSCs and AT-MSCs were isolated and characterized for the characteristic MSC phenotypes. Then, femoral artery ligation and total excision of the femoral artery were performed on C57BL/6 mice to create a CLI model. The cells were evaluated for their in vitro and in vivo biological characteristics for CLI cell therapy. In order to determine these characteristics, the following tests were performed: morphology, flow cytometry, differentiation to osteocyte and adipocyte, wound healing assay, and behavioral tests including Tarlov, Ischemia, Modified ischemia, Function and the grade of limb necrosis scores, donor cell survival assay, and histological analysis. Results Our cellular and functional tests indicated that during 28 days after cell transplantation, BM-MSCs had a great effect on endothelial cell migration, muscle restructure, functional improvements, and neovascularization in ischemic tissues compared with AT-MSCs and control groups. Conclusions Allogeneic BM-MSC transplantation resulted in a more effective recovery from critical limb ischemia compared to AT-MSCs transplantation. In fact, BM-MSC transplantation could be considered as a promising therapy for diseases with insufficient angiogenesis including hindlimb ischemia.


2021 ◽  
Vol 12 (6) ◽  
Author(s):  
HuiYa Li ◽  
DanQing Hu ◽  
Guilin Chen ◽  
DeDong Zheng ◽  
ShuMei Li ◽  
...  

AbstractBoth weak survival ability of stem cells and hostile microenvironment are dual dilemma for cell therapy. Adropin, a bioactive substance, has been demonstrated to be cytoprotective. We therefore hypothesized that adropin may produce dual protective effects on the therapeutic potential of stem cells in myocardial infarction by employing an adropin-based dual treatment of promoting stem cell survival in vitro and modifying microenvironment in vivo. In the current study, adropin (25 ng/ml) in vitro reduced hydrogen peroxide-induced apoptosis in rat bone marrow mesenchymal stem cells (MSCs) and improved MSCs survival with increased phosphorylation of Akt and extracellular regulated protein kinases (ERK) l/2. Adropin-induced cytoprotection was blocked by the inhibitors of Akt and ERK1/2. The left main coronary artery of rats was ligated for 3 or 28 days to induce myocardial infarction. Bromodeoxyuridine (BrdU)-labeled MSCs, which were in vitro pretreated with adropin, were in vivo intramyocardially injected after ischemia, following an intravenous injection of 0.2 mg/kg adropin (dual treatment). Compared with MSCs transplantation alone, the dual treatment with adropin reported a higher level of interleukin-10, a lower level of tumor necrosis factor-α and interleukin-1β in plasma at day 3, and higher left ventricular ejection fraction and expression of paracrine factors at day 28, with less myocardial fibrosis and higher capillary density, and produced more surviving BrdU-positive cells at day 3 and 28. In conclusion, our data evidence that adropin-based dual treatment may enhance the therapeutic potential of MSCs to repair myocardium through paracrine mechanism via the pro-survival pathways.


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