Towards 4D printed scaffolds for tissue engineering: exploiting 3D shape memory polymers to deliver time-controlled stimulus on cultured cells

Shape memory polymers (SMPs) that change shapes as designed by external stimuli have become one of the most promising materials as actuators, sensors, and deployable devices. However, their practical applications...

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In vivo study of the angiogenesis potential of bone marrow-derived mesenchymal stem cell aggregates in their niche like environment

The International Journal of Artificial Organs ◽

10.1177/03913988211025538 ◽

2021 ◽

pp. 039139882110255

Author(s):

Sara Anajafi ◽

Azam Ranjbar ◽

Monireh Torabi-Rahvar ◽

Naser Ahmadbeigi

Keyword(s):

Tissue Engineering ◽

Bone Marrow ◽

Stem Cell ◽

Mesenchymal Stem Cell ◽

Cultured Cells ◽

Morphological Evidence ◽

Cell Aggregates ◽

Plla Scaffold ◽

Significant Difference

Background: Sufficient blood vessel formation in bioengineered tissues is essential in order to keep the viability of the organs. Impaired development of blood vasculatures results in failure of the implanted tissue. The cellular source which is seeded in the scaffold is one of the crucial factors involved in tissue engineering methods. Materials and methods: Considering the notable competence of Bone Marrow derived Mesenchymal Stem Cell aggregates for tissue engineering purposes, in this study BM-aggregates and expanded BM-MSCs were applied without any inductive agent or co-cultured cells, in order to investigate their own angiogenesis potency in vivo. BM-aggregates and BM-MSC were seeded in Poly-L Lactic acid (PLLA) scaffold and implanted in the peritoneal cavity of mice. Result: Immunohistochemistry results indicated that there was a significant difference ( p < 0.050) in CD31+ cells between PLLA scaffolds contained cultured BM-MSC; PLLA scaffolds contained BM-aggregates and empty PLLA. According to morphological evidence, obvious connections with recipient vasculature and acceptable integration with surroundings were established in MSC and aggregate-seeded scaffolds. Conclusion: Our findings revealed cultured BM-MSC and BM-aggregates, capacity in order to develop numerous connections between PLLA scaffold and recipient’s vasculature which is crucial to the survival of tissues, and considerable tendency to develop constructs containing CD31+ endothelial cells which can contribute in vessel’s tube formation.

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Macroporous Superhydrophobic Coatings with Switchable Wettability Enabled by Smart Shape Memory Polymers

Advanced Materials Interfaces ◽

10.1002/admi.202002111 ◽

2021 ◽

pp. 2002111

Author(s):

Calen J. Leverant ◽

Yifan Zhang ◽

Maria A. Cordoba ◽

Sin‐Yen Leo ◽

Nilesh Charpota ◽

...

Keyword(s):

Shape Memory ◽

Shape Memory Polymers ◽

Superhydrophobic Coatings

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Fluid Flow Mechanical Stimulation-Assisted Cartridge Device for the Osteogenic Differentiation of Human Mesenchymal Stem Cells

Micromachines ◽

10.3390/mi12080927 ◽

2021 ◽

Vol 12 (8) ◽

pp. 927

Author(s):

Ki-Taek Lim ◽

Dinesh-K. Patel ◽

Sayan-Deb Dutta ◽

Keya Ganguly

Keyword(s):

Tissue Engineering ◽

Stem Cells ◽

Mesenchymal Stem Cells ◽

Fluid Flow ◽

Osteogenic Differentiation ◽

Flow Condition ◽

Cultured Cells ◽

Human Mesenchymal Stem Cells ◽

Proliferation And Differentiation ◽

Static Conditions

Human mesenchymal stem cells (hMSCs) have the potential to differentiate into different types of mesodermal tissues. In vitro proliferation and differentiation of hMSCs are necessary for bone regeneration in tissue engineering. The present study aimed to design and develop a fluid flow mechanically-assisted cartridge device to enhance the osteogenic differentiation of hMSCs. We used the fluorescence-activated cell-sorting method to analyze the multipotent properties of hMSCs and found that the cultured cells retained their stemness potential. We also evaluated the cell viabilities of the cultured cells via water-soluble tetrazolium salt 1 (WST-1) assay under different rates of flow (0.035, 0.21, and 0.35 mL/min) and static conditions and found that the cell growth rate was approximately 12% higher in the 0.035 mL/min flow condition than the other conditions. Moreover, the cultured cells were healthy and adhered properly to the culture substrate. Enhanced mineralization and alkaline phosphatase activity were also observed under different perfusion conditions compared to the static conditions, indicating that the applied conditions play important roles in the proliferation and differentiation of hMSCs. Furthermore, we determined the expression levels of osteogenesis-related genes, including the runt-related protein 2 (Runx2), collagen type I (Col1), osteopontin (OPN), and osteocalcin (OCN), under various perfusion vis-à-vis static conditions and found that they were significantly affected by the applied conditions. Furthermore, the fluorescence intensities of OCN and OPN osteogenic gene markers were found to be enhanced in the 0.035 mL/min flow condition compared to the control, indicating that it was a suitable condition for osteogenic differentiation. Taken together, the findings of this study reveal that the developed cartridge device promotes the proliferation and differentiation of hMSCs and can potentially be used in the field of tissue engineering.

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