Differentiation of stem cells into mature cells through the use of physical approaches is of great interest. Here, we prepared smart nanoenvironments by cell-imprinted substrates based on chondrocytes, tenocytes, and semifibroblasts as templates and demonstrated their potential for differentiation, redifferentiation, and transdifferentiation. Analysis of shape and upregulation/downregulation of specific genes of stem cells, which were seeded on these cell-imprinted substrates, confirmed that imprinted substrates have the capability to induce specific shapes and molecular characteristics of the cell types that were used as templates for cell-imprinting. Interestingly, immunofluorescent staining of a specific protein in chondrocytes (i.e., collagen type II) confirmed that adipose-derived stem cells, semifibroblasts, and tenocytes can acquire the chondrocyte phenotype after a 14 day culture on chondrocyte-imprinted substrates. In summary, we propose that common polystyrene tissue culture plates can be replaced by this imprinting technique as an effective and promising way to regulate any cell phenotype in vitro with significant potential applications in regenerative medicine and cell-based therapies.

Bioinspired materials can mimic the stem cell environment and modulate stem cell differentiation and proliferation. In this study, biomimetic micro/nanoenvironments were fabricated by cell-imprinted substrates based on mature human keratinocyte morphological templates. The data obtained from atomic force microscopy and field emission scanning electron microscopy revealed that the keratinocyte-cell-imprinted poly(dimethylsiloxane) casting procedure could imitate the surface morphology of the plasma membrane, ranging from the nanoscale to the macroscale, which may provide the required topographical cell fingerprints to induce differentiation. Gene expression levels of the genes analyzed (involucrin, collagen type I, and keratin 10) together with protein expression data showed that human adipose-derived stem cells (ADSCs) seeded on these cell-imprinted substrates were driven to adopt the specific shape and characteristics of keratinocytes. The observed morphology of the ADSCs grown on the keratinocyte casts was noticeably different from that of stem cells cultivated on the stem-cell-imprinted substrates. Since the shape and geometry of the nucleus could potentially alter the gene expression, we used molecular dynamics to probe the effect of the confining geometry on the chain arrangement of simulated chromatin fibers in the nuclei. The results obtained suggested that induction of mature cell shapes onto stem cells can influence nucleus deformation of the stem cells followed by regulation of target genes. This might pave the way for a reliable, efficient, and cheap approach of controlling stem cell differentiation toward skin cells for wound healing applications.

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Knowledge aboutbiomass partitioning of maize grown in arid and semi-arid climatesis scarceand yet essential to select a robust and effective deficit irrigation management (DIM) strategy for these regions.The objectives of this study were to: i)investigate the effects of different levels of water application under two DIM strategies on the root and aboveground characteristics, the response factor to water stress (K y) and irrigation water use efficiency (IWUE) of silage maize at different growth stages, andii) determine the best DIM strategythat 44 would maximize biomass productivity.Field pot experimentswere conducted in Isfahan, 45 Iran,during 2009 and 2010.The twoDIM strategies werefixed irrigation interval-variable 46 irrigation depth (M 1), and variable irrigation interval-fixed irrigation depth (M 2).Each DIM strategy was tested at four water-deficit levels, including: severe, moderate, mild,and a fullirrigation.In M 1 , irrigation intervals were consistent for all irrigation treatmentsbut were varied over the growing season. Treatment effects weremeasured at the10-leaf, 16-leaf, tasseling, milk,and silage harvestcrop growth stages.There was significant effect of irrigation and growth stage on total aboveground biomass (TB), leaf area (LA), root biomass (RB), and root:shoot ratio (RSR)for both DIM strategies during the two years.For M 2 , there was 53 significant difference in TB, LA, RB, and RSR between all irrigation levels at all growth 54 stages.TB production was on the average around 25% higher for M 1 compared to M 2 , even 55 though total applied irrigation water was only 6% higher for M 1 .Comparing the two DIMsshowed that RSR and K y wereboth higherforM 2 , indicating that the crop was more sensitive to this strategy.In conclusion, M 1 was selected as the best management practicesince it had more favorable effects on improving the IWUE and also on the development of maize rootsduring the growing season.

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