Osteogenic Differentiation of Mesenchymal Stem Cells in their Native Niche Like Environment

Niche is an important microenvironment regulating stem cell's natural behavior and its fate. Mesenchymal Stem Cells (MSCs) are the most common cells used in bone tissue engineering. However, common culture procedures do not retain MSCs in their niche and apply in vitro expansion which can cause abnormal behavior. In this study, we propose that, by Keeping MSCs in their native niche, natural behavior of these cells and their interactions are maintained and the quality of differentiation will enhance. In our previous studies, we isolated MSCs kept in their native niche-like environment (native- MSCs) in the form of aggregates. Herein, in order to explore the osteogenic differentiation of these cells, they were isolated from bone marrow, and in vitro osteogenesis was assessed via alizarin red and real time PCR. It was observed that they differentiated after 6 days, which is remarkably faster than the conventional 21-day period. Higher expression of Runx2, Spp1 and alkaline phosphatase in native-MSCs also confirmed in vitro results. We also examine their attachment on poly (L-lactic acid) (PLLA) scaffold. In sum, native-MSCs exhibited faster differentiation than expanded MSCs which proves the importance of keeping stem cells in their niche. List of Abbreviation: Native-MSCs: MSCs which are kept in their niche like environment; Ex-MSCs: Expanded MSCs are common MSCs which isolate and expand based on their adherent properties

Cytotoxicity evaluation and magnetic characteristics of mechano-thermally synthesized CuNi nanoparticles for hyperthermia

CuNi alloys are very well known, both in academia and industry, based on their wide range of applications. In the present investigation, the previously synthesized Cu_0.5Ni_0.5 nanoparticles (NPs) by mechano-thermal method were studied more extensively. Phase composition and morphology of the samples were studied by employing x-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) techniques. The Curie temperature (<em><i>T</i></em>_c) was determined by differential scanning calorimetry (DSC). In vitro cytotoxicity was studied through methyl-thiazolyl-tetrazolium (MTT) assay. XRD and FESEM results indicated the formation of single-phase Cu_0.5Ni_0.5. TEM micrographs showed that the mean particle size of powders is 20 nm. DSC results revealed that <em><i>T</i></em>_c of mechano-thermally synthesized Cu_0.5Ni_0.5 is 44 °C. The MTT assay results confirmed the viability and proliferation of human bone marrow stem cells in contact with Cu_0.5Ni_0.5 NPs. In summary, the fabricated particles were demonstrated to have potential in low concentrations for cancer treatment applications

Osteogenic Differentiation of Mesenchymal Stem Cells in their Native Niche Like Environment

Niche is an important microenvironment regulating stem cell's natural behavior and its fate. Mesenchymal Stem Cells (MSCs) are the most common cells used in bone tissue engineering. However, common culture procedures do not retain MSCs in their niche and apply in vitro expansion which can cause abnormal behavior. In this study, we propose that, by Keeping MSCs in their native niche, natural behavior of these cells and their interactions are maintained and the quality of differentiation will enhance. In our previous studies, we isolated MSCs kept in their native niche-like environment (nativeMSCs) in the form of aggregates. Herein, in order to explore the osteogenic differentiation of these cells, they were isolated from bone marrow, and in vitro osteogenesis was assessed via alizarin red and real time PCR. It was observed that they differentiated after 6 days, which is remarkably faster than the conventional 21-day period. Higher expression of Runx2, Spp1 and alkaline phosphatase in native-MSCs also confirmed in vitro results. We also examine their attachment on poly (L-lactic acid) (PLLA) scaffold. In sum, native-MSCs exhibited faster differentiation than expanded MSCs which proves the importance of keeping stem cells in their niche

Microfluidic fabrication of alendronate-loaded chitosan nanoparticles for enhanced osteogenic differentiation of stem cells

Aims: In this study, we used a cross-junction microfluidic device for preparation of alendronate-loaded chitosan nanoparticles with desired characteristics to introduce a suitable element for bone tissue engineering scaffolds. Main methods: By controlling the reaction condition in microfluidic device, six types of alendronate-loaded chitosan nanoparticles were fabricated which had different physical properties. Hydrodynamic diameter of synthetized particles was evaluated by dynamic light scattering (102 to 215 nm). Nanoparticle morphology was determined by SEM and AFM images. The osteogenic effects of prepared selected nanoparticles on human adipose stem cells (hA-MSCs) were evaluated by assessment of alkaline phosphatase (ALP) activity, calcium deposition, ALP and osteopontin gene expression. Key findings: The highest loading efficiency percentage (LE) was 32.42 ± 2.02. Based on MTT assessment, two samples which had no significant cytotoxicity were chosen for further studies (particle sizes and LE were 142 ± 6.1 nm, 198 ± 16.56 nm, 16.76 ± 3.91 and 32.42 ± 2.02, respectively). In vitro release behavior of nanoparticles displayed pH responsive characteristics. Significant faster release was seen in acidic pH = 5.8 than neutral pH = 7.4. The selected nanoparticles demonstrated higher ALP activity at 14 days in comparison to selected blank sample and osteogenic differentiation media (ODM) and a downregulation at 21 days in comparison to 14 days. Calcium content assay at 21 days displayed significant differences between alendronate-loaded nanoparticles and ODM. ALP and osteopontin mRNA expression was significantly higher than the cells cultured in ODM at 14 and 21 days. Significance: We concluded that our prepared nanoparticles significantly enhanced osteogenic differentiation of hA-MSCs and can be a suitable compartment of bone tissue engineering scaffolds. © 202

Osteoconduction of Unrestricted Somatic Stem Cells on an Electrospun Polylactic-Co-Glycolic Acid Scaffold Coated with Nanohydroxyapatite.

The limitation of traditional bone grafts could be overcome by applying engineered bone constructs, which are mainly produced by seeding suitable stem cells on appropriate scaffolds. So far, bone marrow-derived stromal cells have been the most applied cells in bone tissue engineering, but current data show that unrestricted somatic stem cells (USSCs) from human cord blood might actually be a better stem cell source due to the accessibility and noninvasive procedure of collection. In this study, we cultured USSCs on a plasma-treated electrospun polylactic-co-glycolic acid (PLGA) scaffold coated with nanohydroxyapatite (nHA). Adhesion and proliferation of USSCs on PLGA/nHA were assessed by scanning electron microscopy and MTT assay. Osteogenic differentiation of USSCs into osteoblast lineage cells was evaluated via alkaline phosphatase (ALP) activity and real-time polymerase chain reaction. Our observation showed that USSCs attached and proliferated on PLGA/nHA. Osteogenic differentiation was confirmed by increased ALP activity and OSTEONECTIN expression in USSCs on PLGA/nHA after the 1st week of the osteogenic period. Therefore, using USSCs on electrospun PLGA/nHA is a promising approach in bone tissue engineering

Enhanced proliferation and osteogenic differentiation of mesenchymal stem cells by diopside coated Poly-L-lactic Acid-Based nanofibrous scaffolds

In this study, diopside coated Poly-L-lactic acid-based (PLLA/Diopside) and Poly-L-lactic acid along with pluronic acid (PLLA-P123/Diopside) scaffolds were fabricated by electrospinning to improve the drawbacks with pure polymer and pure bioceramic scaffolds in bone tissue engineering application. The surface morphology, hydrophilicity, and mechanical strength were evaluated. The cell proliferation, differentiation, and expression of osteo related genes were evaluated by measuring the basic osteogenic markers and real time polymerase chain reaction, respectively. Diopside coated Poly-L-lactic acid-based nanofibrous scaffolds have improved surface and biological properties making them a good promising candidate for proliferation and osteogenic differentiation in bone repair and regeneration compared to nanofibrous scaffolds without diopside. Especially, post plasma treated diopside coated PLLA demonstrated better osteogenesis and expression of osteo related genes than the other groups. Although, diopside coated PLLA-P123 composite in comparison with PLLA-Plasma/diopside scaffolds were showed less osteogenesis and expression of osteo related genes, but the results were comparable. Therefore, diopside coated (PLLA-plasma and PLLA/P123 composite) scaffolds could be ideal cost effective grafts in bone repair and replacement therapy. © 2021 Taylor & Francis Group, LLC