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The effects of laminins 332 and 411 (LM-332 and LM-411) on the epithelial-mesenchymal transformation of colorectal cancer cells (lines HT-29, HCT-116, and RKO) with different metastatic potential were studied. Culturing of RKO cells on both laminins was associated with modification of the cell shape, which became more spindle-like or stellate, and with higher expression of EMT-associated transcription factors SNAI1 and ZEB1. In addition, culturing on LM-332 led to a decrease in the expression of laminin α5 chain (LAMA5), while culturing on LM-411 led to an increase in the expression of a cell-cell junction component (DSP). Culturing of HT-29 cells on LM-332 was associated with the formation of more close contacts between the cells and by a higher expression of epithelial markers (CDH1 and DSP genes) and a decrease in SNAI1 expression. Culturing of HCT-116 cells on both laminins led to a decrease in FN1 expression, on LM-332 - to an increase in laminin α4 chain (LAMA4) expression, and on LM-411 - to a lesser expression of LAMA4 and transcription factors SNAI2 and ZEB1. These data indicated that colorectal cancer cell adhesion to laminins contributed to the probability of epithelial-mesenchymal transformation of cells. The direction of this transformation seemed to depend on the initial characteristics of the cells.

Mechanical stimulation affects growth and differentiation of stem cells. This may be used to guide lineage-specific cell fate decisions and therefore opens fascinating opportunities for stem cell biology and regenerative medicine. Several studies demonstrated functional and molecular effects of mechanical stimulation but on first sight these results often appear to be inconsistent. Comparison of such studies is hampered by a multitude of relevant parameters that act in concert. There are notorious differences between species, cell types, and culture conditions. Furthermore, the utilized culture substrates have complex features, such as surface chemistry, elasticity, and topography. Cell culture substrates can vary from simple, flat materials to complex 3D scaffolds. Last but not least, mechanical forces can be applied with different frequency, amplitude, and strength. It is therefore a prerequisite to take all these parameters into consideration when ascribing their specific functional relevance-and to only modulate one parameter at the time if the relevance of this parameter is addressed. Such research questions can only be investigated by interdisciplinary cooperation. In this review, we focus particularly on mesenchymal stem cells and pluripotent stem cells to discuss relevant parameters that contribute to the kaleidoscope of mechanical stimulation of stem cells.

We studied the behavior of retinal pigment epithelial cells from adult human eye derived from different donors in different culturing systems: on plastic, in collagen gel, and on decellularized neural retina substrate. The cells diverge into two subpopulations similar by their morphology and behavior: one subpopulation migrated to the surface of the dense substrate and the other formed spheroid structures consisting of aggregated cells. This fact confirms the data on genetically-predetermined phenotypic heterogeneity of retinal pigment epithelium cells that should be taken into account when using these cells in tissue engineering.

Mesenchymal stromal cells from deciduous teeth in 2D- and 3D-cultures on culture plastic, silicate glass, porous polystyrene, and experimental polylactoglycolide matrices were visualized by scanning electron microscopy with lanthanide contrasting. Supravital staining of cell cultures with a lanthanide-based dye (neodymium chloride) preserved normal cell morphology and allowed assessment of the matrix properties of the carriers. The developed approach can be used for the development of biomaterials for tissue engineering.

In this in vitro study ovine osteoblast-like cells were cultured on seven different alloplastic biomaterials used for augmentation and for reconstruction of bone defects in dental and craniomaxillofacial surgery. The aim of this study was to examine the growth behaviour (viability, cell density and morphology) of ovine osteoblast-like cells on the investigated biomaterials to get knowledge which biomaterial is qualified to act as a cell carrier system in further in vivo experiments. The biomaterials were either synthetically manufactured or of natural origin. As synthetically manufactured biomaterials Ethisorb, MakroSorb, PalacosR, and PDS film were used. As biomaterials of natural origin BeriplastP, Bio-Oss and Titanmesh were investigated. The cell proliferation and cell colonization were analyzed by a proliferation assay and scanning electron microscopy. Osteoblast-like cells proliferated and attached on all biomaterials, except on Beriplast. On Ethisorb the highest cell proliferation rate was measured followed by PalacosR. Both biomaterials offer suitable growth and proliferation conditions for ovine osteoblast-like cells. The proliferation rates of Bio-Oss, MakroSorb, PDS-film and Titanmesh were low and SEM examinations of these materials showed less spread osteoblast-like cells. The results showed that ovine osteoblast-like cells appear to be sensitive to substrate composition and topography. This in vitro study provides the basis for further in vivo studies using the sheep model to examine the biocompatibility and the long-term interaction between the test material and tissue (bone regeneration).