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Stem Cells in Aggregate Form to Enhance Chondrogenesis in Hydrogels.

Sridharan B, Lin SM, Hwu AT, Laflin AD, Detamore MS - PLoS ONE (2015)

Bottom Line: Despite being differing cell sources, both rBMSC and hWJC aggregates were consistent in outperforming cell suspension control groups in biosynthesis and chondrogenesis.Higher cell density impacted biosynthesis favorably, and the number of aggregates positively influenced chondrogenesis.Therefore, we recommend that investigators employing hydrogels consider using cells in an aggregate form for enhanced chondrogenic performance.

View Article: PubMed Central - PubMed

Affiliation: Bioengineering Graduate Program, University of Kansas, Lawrence, Kansas, United States of America.

ABSTRACT
There are a variety of exciting hydrogel technologies being explored for cartilage regenerative medicine. Our overall goal is to explore whether using stem cells in an aggregate form may be advantageous in these applications. 3D stem cell aggregates hold great promise as they may recapitulate the in vivo skeletal tissue condensation, a property that is not typically observed in 2D culture. We considered two different stem cell sources, human umbilical cord Wharton's jelly cells (hWJCs, currently being used in clinical trials) and rat bone marrow-derived mesenchymal stem cells (rBMSCs). The objective of the current study was to compare the influence of cell phenotype, aggregate size, and aggregate number on chondrogenic differentiation in a generic hydrogel (agarose) platform. Despite being differing cell sources, both rBMSC and hWJC aggregates were consistent in outperforming cell suspension control groups in biosynthesis and chondrogenesis. Higher cell density impacted biosynthesis favorably, and the number of aggregates positively influenced chondrogenesis. Therefore, we recommend that investigators employing hydrogels consider using cells in an aggregate form for enhanced chondrogenic performance.

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Related in: MedlinePlus

Schematic representation of the hanging down approach and aggregate-encapsulation in agarose hydrogels.The aggregates/CS is encapsulated in pre-polymer solution and undergoes thermal crosslinking to form the hydrogel.
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pone.0141479.g001: Schematic representation of the hanging down approach and aggregate-encapsulation in agarose hydrogels.The aggregates/CS is encapsulated in pre-polymer solution and undergoes thermal crosslinking to form the hydrogel.

Mentions: Aggregates for the current study were generated by the hanging drop technique [23]. Cellular suspensions (hWJC & rBMSC) were prepared at two concentrations, either 10.0×106 or 20.0×106 cells/mL, in respective media. Droplets of cell suspensions at a controlled volume of 10 μL that had 10,000 or 20,000 cells, respectively, were pipetted in an array onto the inside surface of a petri dish lid using a 10 μL pipette (Eppendorf, Hauppauge, NY), making sure that the droplets had a safe distance between each other to prevent collision. The cells were allowed to aggregate overnight, aided by gravity when the petri dish was reversed (Fig 1). The petri dish bottom was then filled with PBS to prevent drying of these droplets. After 24 hours, the cell aggregates were collected from the dish with a 1 mL pipette and then encapsulated in agarose hydrogels as described below.


Stem Cells in Aggregate Form to Enhance Chondrogenesis in Hydrogels.

Sridharan B, Lin SM, Hwu AT, Laflin AD, Detamore MS - PLoS ONE (2015)

Schematic representation of the hanging down approach and aggregate-encapsulation in agarose hydrogels.The aggregates/CS is encapsulated in pre-polymer solution and undergoes thermal crosslinking to form the hydrogel.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4697858&req=5

pone.0141479.g001: Schematic representation of the hanging down approach and aggregate-encapsulation in agarose hydrogels.The aggregates/CS is encapsulated in pre-polymer solution and undergoes thermal crosslinking to form the hydrogel.
Mentions: Aggregates for the current study were generated by the hanging drop technique [23]. Cellular suspensions (hWJC & rBMSC) were prepared at two concentrations, either 10.0×106 or 20.0×106 cells/mL, in respective media. Droplets of cell suspensions at a controlled volume of 10 μL that had 10,000 or 20,000 cells, respectively, were pipetted in an array onto the inside surface of a petri dish lid using a 10 μL pipette (Eppendorf, Hauppauge, NY), making sure that the droplets had a safe distance between each other to prevent collision. The cells were allowed to aggregate overnight, aided by gravity when the petri dish was reversed (Fig 1). The petri dish bottom was then filled with PBS to prevent drying of these droplets. After 24 hours, the cell aggregates were collected from the dish with a 1 mL pipette and then encapsulated in agarose hydrogels as described below.

Bottom Line: Despite being differing cell sources, both rBMSC and hWJC aggregates were consistent in outperforming cell suspension control groups in biosynthesis and chondrogenesis.Higher cell density impacted biosynthesis favorably, and the number of aggregates positively influenced chondrogenesis.Therefore, we recommend that investigators employing hydrogels consider using cells in an aggregate form for enhanced chondrogenic performance.

View Article: PubMed Central - PubMed

Affiliation: Bioengineering Graduate Program, University of Kansas, Lawrence, Kansas, United States of America.

ABSTRACT
There are a variety of exciting hydrogel technologies being explored for cartilage regenerative medicine. Our overall goal is to explore whether using stem cells in an aggregate form may be advantageous in these applications. 3D stem cell aggregates hold great promise as they may recapitulate the in vivo skeletal tissue condensation, a property that is not typically observed in 2D culture. We considered two different stem cell sources, human umbilical cord Wharton's jelly cells (hWJCs, currently being used in clinical trials) and rat bone marrow-derived mesenchymal stem cells (rBMSCs). The objective of the current study was to compare the influence of cell phenotype, aggregate size, and aggregate number on chondrogenic differentiation in a generic hydrogel (agarose) platform. Despite being differing cell sources, both rBMSC and hWJC aggregates were consistent in outperforming cell suspension control groups in biosynthesis and chondrogenesis. Higher cell density impacted biosynthesis favorably, and the number of aggregates positively influenced chondrogenesis. Therefore, we recommend that investigators employing hydrogels consider using cells in an aggregate form for enhanced chondrogenic performance.

Show MeSH
Related in: MedlinePlus