Increased Adipogenesis of Human Adipose-Derived Stem Cells on Polycaprolactone Fiber Matrices

Abstract

With accelerating rates of obesity and type 2 diabetes world-wide, interest in studying the adipocyte and adipose tissue is increasing. Human adipose derived stem cells - differentiated to adipocytes in vitro - are frequently used as a model system for white adipocytes, as most of their pathways and functions resemble mature adipocytes in vivo. However, these cells are not completely like in vivo mature adipocytes. Hosting the cells in a more physiologically relevant environment compared to conventional two-dimensional cell culturing on plastic surfaces, can produce spatial cues that drive the cells towards a more mature state. We investigated the adipogenesis of adipose derived stem cells on electro spun polycaprolactone matrices and compared functionality to conventional two-dimensional cultures as well as to human primary mature adipocytes. To assess the degree of adipogenesis we measured cellular glucose-uptake and lipolysis and used a range of different methods to evaluate lipid accumulation. We compared the averaged results from a whole population with the single cell characteristics – studied by coherent anti-Stokes Raman scattering microscopy - to gain a comprehensive picture of the cell phenotypes. In adipose derived stem cells differentiated on a polycaprolactone-fiber matrix; an increased sensitivity in insulin-stimulated glucose uptake was detected when cells were grown on either aligned or random matrices. Furthermore, comparing differentiation of adipose derived stem cells on aligned polycaprolactone-fiber matrixes, to those differentiated in two-dimensional cultures showed, an increase in the cellular lipid accumulation, and hormone sensitive lipase content. In conclusion, we propose an adipocyte cell model created by differentiation of adipose derived stem cells on aligned polycaprolactone-fiber matrices which demonstrates increased maturity, compared to 2D cultured cells.

A comparative evaluation of the effect of polymer chemistry and fiber orientation on mesenchymal stem cell differentiation

“…This supports previous work purporting the use of PDO scaffolds for adipose stem cell culture . Enhanced differentiation of mesenchymal stem cells on aligned over randomly orientated electrospun scaffolds is also supported on electrospun polycaprolactone scaffolds . However, it has been shown that adipogenic gene expression ( PPARG ) is lower on aligned compared with randomly orientated fibers of electrospun poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate scaffolds .…”

“…27 Enhanced differentiation of mesenchymal stem cells on aligned over randomly orientated electrospun scaffolds is also supported on electrospun polycaprolactone scaffolds. 28 However, it has been shown that adipogenic gene expression (PPARG) is lower on aligned compared with randomly orientated fibers of electrospun poly(3-hydroxybutyrate-co-3-hydroxyhexanoate scaffolds. 29 This difference was seen when cultured in noninducing but not inducing medium and suggests that fiber orientation-effects on adipogenic differentiation are influenced by the biological milieu.…”

Aligned nanofiber material supports cell growth and increases osteogenesis in canine adipose‐derived mesenchymal stem cells in vitro

“…On the other hand, LPL gene expression increased in random‐oriented PCL plates. A study by Brannmark et al found increased gene expression of PPARγ2 and LPL in human adipocytes compared to undifferentiated ADMSCs cells cultured in control, aligned‐, and random‐oriented PCL plates; however, no difference in genes expression were observed between adipocytes cultured in 3‐D compared to control 2‐D plates. In that study, authors have also reported that expression of other adipogenic markers, such as β‐adrenergic receptors1&2 and PPARγ coativator1‐beta in adipocytes were not significantly different compared to undifferentiated cells, and the expression of Adenosine A1 receptor was even downregulated in adipocytes …”

Opportunities and challenges in three-dimensional brown adipogenesis of stem cells

“…Compared to 2D culture, 3D culture for adipogenesis in general could: 1) deposit an extensive ECM network (Grayson et al, 2004), 2) recapitulate adipose stem cell microenvironments (Yang et al, 2010), 3) enhance adipogenic differentiation, exhibiting more mature adipogenesis of stem cells (Gerlach et al, 2012), efficient lipid accumulation and in vivo-like organogenesis (Daquinag et al, 2013), expression of adipocyte-specific markers (Hong et al, 2005; Neubauer et al, 2005; Stacey et al, 2009) as well as VEGF (Girandon et al, 2011), and increase secretion of adipokines such as leptin (Kang et al, 2005), 4) be more sensitive to insulin-stimulated glucose uptake and drug treatment (Brännmark et al, 2014; Turner et al, 2014), 5) allow long-term survival (Neuss et al, 2008a), and 6) be feasible to manipulate cellular microenvironments for adipogenesis (Daya et al, 2007). …”