Publications by authors named "Yasaman Zamani"

5 Publications

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Osteogenic and Angiogenic Synergy of Human Adipose Stem Cells and Human Umbilical Vein Endothelial Cells Cocultured in a Modified Perfusion Bioreactor.

Organogenesis 2021 Jul 29:1-16. Epub 2021 Jul 29.

Department of Biomedical Engineering, Research Center for New Technologies in Life Science Engineering, University of Tehran, Tehran, Iran.

Synergistic promotion of angiogenesis and osteogenesis in bone tissue-engineered constructs remains a crucial clinical challenge, which might be overcome by simultaneous employment of superior techniques including coculture systems, differentiation-stimulated factors, combinatorial scaffolds and bioreactors.Current study investigated the effect of flow perfusion along with coculture of human adipose stem cells (hASCs) and human umbilical vein endothelial cells (HUVECs) on osteogenic and angiogenic differentiation.Pre-treated hASCs with 1,25-dihydroxyvitamin D were seeded onto poly(lactic-co-glycolic acid)/β-tricalcium phosphate/polycaprolactone (PLGA/β-TCP/PCL) scaffold with/without HUVECs, and cultured for 14 days within a flask or modified perfusion bioreactor. Analysis of osteogenic and angiogenic gene expression, alkaline phosphatase (ALP) activity and ALP staining indicates a synergistic effect of perfusion flow and coculture system on osteogenic and angiogenic differentiation. The advantage of modified perfusion bioreactor is its five-branch flow distributor which directly connect to the porous PCL hollow fibers embedded in the 3D scaffold to improve flow and flow-induced shear stress uniformity.Dynamic coculture increased VEGF by 6-fold, VEGF by 2-fold, and Endothelin-1 by 4-fold, relative to dynamic monoculture. Static coculture enhanced osteogenic and angiogenic differentiation, compared with static monoculture. Although dynamic coculture is in preference to static coculture due to significant increase in ALP activity and promoted angiogenic marker expression. Our finding is the first to indicate that the modified perfusion bioreactor combined with the beneficial cell-cell crosstalk in pre-treated hASC/HUVEC cocultures provides a synergy between osteogenic and angiogenic differentiation of the accumulation of cells, suggesting that it represents a promising approach for regeneration of critical-sized bone defects.
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http://dx.doi.org/10.1080/15476278.2021.1954769DOI Listing
July 2021

Increased Osteogenic Potential of Pre-Osteoblasts on Three-Dimensional Printed Scaffolds Compared to Porous Scaffolds for Bone Regeneration.

Iran Biomed J 2021 03 1;25(2):78-87. Epub 2021 Mar 1.

Department of Oral and Maxillofacial Surgery/Oral Pathology, Amsterdam University Medical Centers-location VUmc and Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam Movement Sciences, Amsterdam, the Netherlands.

Background: One of the main challenges with conventional scaffold fabrication methods is the inability to control scaffold architecture. Recently, scaffolds with controlled shape and architecture have been fabricated using three-dimensional printing (3DP). Herein, we aimed to determine whether the much tighter control of microstructure of 3DP poly(lactic-co-glycolic) acid/β-tricalcium phosphate (PLGA/β-TCP) scaffolds is more effective in promoting osteogenesis than porous scaffolds produced by solvent casting/porogen leaching.

Methods: Physical and mechanical properties of porous and 3DP scaffolds were studied. The response of pre-osteoblasts to the scaffolds was analyzed after 14 days.

Results: TThe 3DP scaffolds had a smoother surface (Ra: 22 ± 3 µm) relative to the highly rough surface of porous scaffolds (Ra: 110 ± 15 µm). Water contact angle was 112 ± 4° on porous and 76 ± 6° on 3DP scaffolds. Porous and 3DP scaffolds had the pore size of 408 ± 90 and 315 ± 17 µm and porosity of 85 ± 5% and 39 ± 7%, respectively. Compressive strength of 3DP scaffolds (4.0 ± 0.3 MPa) was higher than porous scaffolds (1.7 ± 0.2 MPa). Collagenous matrix deposition was similar on both scaffolds. Cells proliferated from day 1 to day 14 by fourfold in porous and by 3.8-fold in 3DP scaffolds. Alkaline phosphatase (ALP) activity was 21-fold higher in 3DP scaffolds than porous scaffolds.

Conclusion: The 3DP scaffolds show enhanced mechanical properties and ALP activity compared to porous scaffolds in vitro, suggesting that 3DP PLGA/β-TCP scaffolds are possibly more favorable for bone formation.
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http://dx.doi.org/10.29252/ibj.25.2.78DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7921523PMC
March 2021

3D-printed poly(Ɛ-caprolactone) scaffold with gradient mechanical properties according to force distribution in the mandible for mandibular bone tissue engineering.

J Mech Behav Biomed Mater 2020 04 14;104:103638. Epub 2020 Jan 14.

Department of Oral Cell Biology and Functional Anatomy, Academic Centre for Dentistry Amsterdam (ACTA)-University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, Gustav Mahlerlaan 3004, 1081 LA Amsterdam, the Netherlands. Electronic address:

In bone tissue engineering, prediction of forces induced to the native bone during normal functioning is important in the design, fabrication, and integration of a scaffold with the host. The aim of this study was to customize the mechanical properties of a layer-by-layer 3D-printed poly(ϵ-caprolactone) (PCL) scaffold estimated by finite element (FE) modeling in order to match the requirements of the defect, to prevent mechanical failure, and ensure optimal integration with the surrounding tissue. Forces and torques induced on the mandibular symphysis during jaw opening and closing were predicted by FE modeling. Based on the predicted forces, homogeneous-structured PCL scaffolds with 3 different void sizes (0.3, 0.6, and 0.9 mm) were designed and 3D-printed using an extrusion based 3D-bioprinter. In addition, 2 gradient-structured scaffolds were designed and 3D-printed. The first gradient scaffold contained 2 regions (0.3 mm and 0.6 mm void size in the upper and lower half, respectively), whereas the second gradient scaffold contained 3 regions (void sizes of 0.3, 0.6, and 0.9 mm in the upper, middle and lower third, respectively). Scaffolds were tested for their compressive and tensile strength in the upper and lower halves. The actual void size of the homogeneous scaffolds with designed void size of 0.3, 0.6, and 0.9 mm was 0.20, 0.59, and 0.95 mm, respectively. FE modeling showed that during opening and closing of the jaw, the highest force induced on the symphysis was a compressive force in the transverse direction. The compressive force was induced throughout the symphyseal line and reduced from top (362.5 N, compressive force) to bottom (107.5 N, tensile force) of the symphysis. Compressive and tensile strength of homogeneous scaffolds decreased by 1.4-fold to 3-fold with increasing scaffold void size. Both gradient scaffolds had higher compressive strength in the upper half (2 region-gradient scaffold: 4.9 MPa; 3 region-gradient scaffold: 4.1 MPa) compared with the lower half (2 region-gradient scaffold: 2.5 MPa; 3 region-gradient scaffold: 2.7 MPa) of the scaffold. 3D-printed PCL scaffolds had higher compressive strength in the scaffold layer-by-layer building direction compared with the side direction, and a very low tensile strength in the scaffold layer-by-layer building direction. Fluid shear stress and fluid pressure distribution in the gradient scaffolds were more homogeneous than in the 0.3 mm void size scaffold and similar to the 0.6 mm and 0.9 mm void size scaffolds. In conclusion, these data show that the mechanical properties of 3D-printed PCL scaffolds can be tailored based on the predicted forces on the mandibular symphysis. These 3D-printed PCL scaffolds had different mechanical properties in scaffold building direction compared with the side direction, which should be taken into account when placing the scaffold in the defect site. Our findings might have implications for improved performance and integration of scaffolds with native tissue.
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http://dx.doi.org/10.1016/j.jmbbm.2020.103638DOI Listing
April 2020

Enhanced osteogenic activity by MC3T3-E1 pre-osteoblasts on chemically surface-modified poly(ε-caprolactone) 3D-printed scaffolds compared to RGD immobilized scaffolds.

Biomed Mater 2018 11 13;14(1):015008. Epub 2018 Nov 13.

Department of Biomedical Engineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran, Iran. Department of Biomedical Engineering, Research Center for New Technologies in Life Science Engineering, University of Tehran, Tehran, Iran.

In bone tissue engineering, the intrinsic hydrophobicity and surface smoothness of three-dimensional (3D)-printed poly(ε-caprolactone) scaffolds hamper cell attachment, proliferation and differentiation. This intrinsic hydrophobicity of poly(ε-caprolactone) can be overcome by surface modifications, such as surface chemical modification or immobilization of biologically active molecules on the surface. Moreover, surface chemical modification may alter surface smoothness. Whether surface chemical modification or immobilization of a biologically active molecule on the surface is more effective to enhance pre-osteoblast proliferation and differentiation is currently unknown. Therefore, we aimed to investigate the osteogenic response of MC3T3-E1 pre-osteoblasts to chemically surface-modified and RGD-immobilized 3D-printed poly(ε-caprolactone) scaffolds. Poly(ε-caprolactone) scaffolds were 3D-printed consisting of strands deposited layer by layer with alternating 0°/90° lay-down pattern. 3D-printed poly(ε-caprolactone) scaffolds were surface-modified by either chemical modification using 3 M sodium hydroxide (NaOH) for 24 or 72 h, or by RGD-immobilization. Strands were visualized by scanning electron microscopy. MC3T3-E1 pre-osteoblasts were seeded onto the scaffolds and cultured up to 14 d. The strands of the unmodified poly(ε-caprolactone) scaffold had a smooth surface. NaOH treatment changed the scaffold surface topography from smooth to a honeycomb-like surface pattern, while RGD immobilization did not alter the surface topography. MC3T3-E1 pre-osteoblast seeding efficiency was similar (44%-54%) on all scaffolds after 12 h. Cell proliferation increased from day 1 to day 14 in unmodified controls (1.9-fold), 24 h NaOH-treated scaffolds (3-fold), 72 h NaOH-treated scaffolds (2.2-fold), and RGD-immobilized scaffolds (4.5-fold). At day 14, increased collagenous matrix deposition was achieved only on 24 h NaOH-treated (1.8-fold) and RGD-immobilized (2.2-fold) scaffolds compared to unmodified controls. Moreover, 24 h, but not 72 h, NaOH-treated scaffolds, increased alkaline phosphatase activity by 5-fold, while the increase by RGD immobilization was only 2.5-fold. Only 24 h NaOH-treated scaffolds enhanced mineralization (2.0-fold) compared to unmodified controls. In conclusion, RGD immobilization (0.011 μg mg scaffold) on the surface and 24 h NaOH treatment of the surface of 3D-printed PCL scaffold both enhance pre-osteoblast proliferation and matrix deposition while only 24 h NaOH treatment results in increased osteogenic activity, making it the treatment of choice to promote bone formation by osteogenic cells.
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http://dx.doi.org/10.1088/1748-605X/aaeb82DOI Listing
November 2018

Response of human mesenchymal stem cells to patterned and randomly oriented poly(vinyl alcohol) nano-fibrous scaffolds surface-modified with Arg-Gly-Asp (RGD) ligand.

Appl Biochem Biotechnol 2013 Nov 21;171(6):1513-24. Epub 2013 Aug 21.

Biomaterial Group, Faculty of Biomedical Engineering, Amirkabir University of Technology, Hafez Ave, Tehran, 15875-4413, Iran.

The aim of this study was to obtain a better insight of how nano-fibrous scaffolds can affect human mesenchymal stem cells responses. Therefore, in this study, using electrospinning technique, poly(vinyl alcohol) (PVA) nano-fibers with two different patterns were prepared. In the first structure, PVA nano-fibers were oriented randomly and in the second structure, nano-fibers were electrospun in such a way that a special pattern was obtained. In order to enhance their stability, scaffolds were cross-linked using glutaraldehyde vapor. RGD immobilization was used to improve cell adhesion properties of the scaffolds. SEM micrographs demonstrated that the cell adhesion was effectively enhanced after RGD immobilization and higher cell densities were observed on RGD-modified scaffolds. Randomly oriented nano-fibers showed better cell adhesion compared to patterned structure. Patterned structure also revealed slightly lower cell viability compared to random nano-fibers. Finally, it was assumed that randomly oriented nano-fibers provide a more favorable surface for cells.
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http://dx.doi.org/10.1007/s12010-013-0442-5DOI Listing
November 2013
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