Publications by authors named "Sonal R Sampat"

3 Publications

  • Page 1 of 1

Growth factor priming differentially modulates components of the extracellular matrix proteome in chondrocytes and synovium-derived stem cells.

PLoS One 2014 7;9(2):e88053. Epub 2014 Feb 7.

Department of Biomedical Engineering, Columbia University, New York, New York, United States of America.

To make progress in cartilage repair it is essential to optimize protocols for two-dimensional cell expansion. Chondrocytes and SDSCs are promising cell sources for cartilage repair. We previously observed that priming with a specific growth factor cocktail (1 ng/mL transforming growth factor-β1, 5 ng/mL basic fibroblast growth factor, and 10 ng/mL platelet-derived growth factor-BB) in two-dimensional culture, led to significant improvement in mechanical and biochemical properties of synovium-derived stem cell (SDSC)-seeded constructs. The current study assessed the effect of growth factor priming on the proteome of canine chondrocytes and SDSCs. In particular, growth factor priming modulated the proteins associated with the extracellular matrix in two-dimensional cultures of chondrocytes and SDSCs, inducing a partial dedifferentiation of chondrocytes (most proteins associated with cartilage were down-regulated in primed chondrocytes) and a partial differentiation of SDSCs (some collagen-related proteins were up-regulated in primed SDSCs). However, when chondrocytes and SDSCs were grown in pellet culture, growth factor-primed cells maintained their chondrogenic potential with respect to glycosaminoglycan and collagen production. In conclusion, the strength of the label-free proteomics technique is that it allows for the determination of changes in components of the extracellular matrix proteome in chondrocytes and SDSCs in response to growth factor priming, which could help in future tissue engineering strategies.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0088053PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3917883PMC
May 2015

Applied osmotic loading for promoting development of engineered cartilage.

J Biomech 2013 Oct 30;46(15):2674-81. Epub 2013 Aug 30.

Department of Biomedical Engineering, Columbia University, New York, NY, USA.

This study investigated the potential use of static osmotic loading as a cartilage tissue engineering strategy for growing clinically relevant grafts from either synovium-derived stem cells (SDSCs) or chondrocytes. Bovine SDSCs and chondrocytes were individually encapsulated in 2% w/v agarose and divided into chondrogenic media of osmolarities 300 (hypotonic), 330 (isotonic), and 400 (hypertonic, physiologic) mOsM for up to 7 weeks. The application of hypertonic media to constructs comprised of SDSCs or chondrocytes led to increased mechanical properties as compared to hypotonic (300mOsM) or isotonic (330mOsM) media (p<0.05). Constant exposure of SDSC-seeded constructs to 400mOsM media from day 0 to day 49 yielded a Young's modulus of 513±89kPa and GAG content of 7.39±0.52%ww on day 49, well within the range of values of native, immature bovine cartilage. Primary chondrocyte-seeded constructs achieved almost as high a Young's modulus, reaching 487±187kPa and 6.77±0.54%ww (GAG) for the 400mOsM condition (day 42). These findings suggest hypertonic loading as a straightforward strategy for 3D cultivation with significant benefits for cartilage tissue engineering strategies. In an effort to understand potential mechanisms responsible for the observed response, cell volume measurements in response to varying osmotic conditions were evaluated in relation to the Boyle-van't Hoff (BVH) law. Results confirmed that chondrocytes behave as perfect osmometers; however SDSCs deviated from the BVH relation.
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http://dx.doi.org/10.1016/j.jbiomech.2013.07.043DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3902123PMC
October 2013

Growth factor priming of synovium-derived stem cells for cartilage tissue engineering.

Tissue Eng Part A 2011 Sep 24;17(17-18):2259-65. Epub 2011 Jun 24.

Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA.

This study investigated the potential use of synovium-derived stem cells (SDSCs) as a cell source for cartilage tissue engineering. Harvested SDSCs from juvenile bovine synovium were expanded in culture in the presence (primed) or absence (unprimed) of growth factors (1 ng/mL transforming growth factor-β(1), 10 ng/mL platelet-derived growth factor-ββ, and 5 ng/mL basic fibroblast growth factor-2) and subsequently seeded into clinically relevant agarose hydrogel scaffolds. Constructs seeded with growth factor-primed SDSCs that received an additional transient application of transforming growth factor-β(3) for the first 21 days (release) exhibited significantly better mechanical and biochemical properties compared to constructs that received sustained growth factor stimulation over the entire culture period (continuous). In particular, the release group exhibited a Young's modulus (267±96 kPa) approaching native immature bovine cartilage levels, with corresponding glycosaminoglycan content (5.19±1.45%ww) similar to native values, within 7 weeks of culture. These findings suggest that SDSCs may serve as a cell source for cartilage tissue engineering applications.
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http://dx.doi.org/10.1089/ten.TEA.2011.0155DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3161099PMC
September 2011
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