Polysaccharide-coated PCL nanofibers for wound dressing applications.

Polysaccharide-based nanofibers with a multilayered structure are prepared by combining electrospinning (ESP) and layer-by-layer (LBL) deposition techniques. Charged nanofibers are firstly prepared by electrospinning poly(ε-caprolactone) (PCL) with a block-copolymer bearing carboxylic acid functions. After deprotonation of the acid groups, the layer-by-layer deposition of polyelectrolyte polysaccharides, notably chitosan and hyaluronic acid, is used to coat the electrospun fibers.

Development of a chitosan nanofibrillar scaffold for skin repair and regeneration.

The final goal of the present study was the development of a 3-D chitosan dressing that would shorten the healing time of skin wounds by stimulating migration, invasion, and proliferation of the relevant cutaneous resident cells. Three-dimensional chitosan nanofibrillar scaffolds produced by electrospinning were compared with evaporated films and freeze-dried sponges for their biological properties. The nanofibrillar structure strongly improved cell adhesion and proliferation in vitro.

Development of a procedure to simultaneously isolate RNA, DNA, and proteins for [corrected] characterizing cells invading or cultured on chitosan scaffolds.

For many years, chitosan and its derivatives have been considered to be promising biomaterials for tissue engineering and repair. However, information regarding their biological effect on cell phenotype is usually limited to evaluation of cell proliferation and survival, overlooking proteomic and transcriptomic analysis. This is largely related to the lack of efficient and quantitative procedures for protein and nucleic acid purification from cells cultured on, or inside, chitosan scaffold.

Knockdown of PKD1 in normal human epidermal keratinocytes increases mRNA expression of keratin 10 and involucrin: early markers of keratinocyte differentiation.

Subconfluent normal human keratinocytes exhibit autonomous (autocrine growth factor driven) proliferation and express the specific markers for keratinocyte proliferation K5 (keratin 5) and K14 (keratin 14). Utilizing this model the effects of PKD1 (Protein kinase D1) knockdown on activation of differentiation was studied. siRNA approach was applied to achieve specific knockdown of PKD1 and the mRNA levels of different keratinocyte markers -- K14 and PCNA (markers of basal proliferating keratinocytes), involucrin and K10 (early differentiation markers) were analyzed.

Effects of the CDK-inhibitor CYC202 on p38 MAPK, ERK1/2 and c-Myc activities in papillomavirus type 16 E6- and E7-transformed human keratinocytes.

In the present study, we have investigated the effect of the chemical CDK-inhibitor CYC202 on E6 and E7-transformed keratinocytes, in which the function of the cellular cell cycle inhibitor p21Cip1 is abrogated by the viral genes. The cyto-toxicity and the inhibition of the cell growth were analysed by MTT assay and analysis of DNA synthesis respectively. The effect on some signalling molecules was tested by Western blot analysis.

Effects of the cyclin-dependent kinase inhibitor CYC202 (R-roscovitine) on the physiology of cultured human keratinocytes.

CYC202 (R-roscovitine) is a potent cyclin-dependent kinase inhibitor, investigated as a potential anti-cancer agent. The knowledge of the action of this pharmacological agent on normal human cells is still limited. In this study, we have explored the effects of the cyclin-dependent kinase inhibitor CYC202 on normal human epidermal keratinocytes.

Cholesterol depletion upregulates involucrin expression in epidermal keratinocytes through activation of p38.

Cholesterol has been recently suggested to regulate the early steps of keratinocyte differentiation through lipid rafts. In many cell types, depletion of cholesterol activates signaling proteins like epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), or extracellular signal-regulated kinase (ERK) known to affect cell differentiation. In this study, we explored the effects of cholesterol depletion on the phenotype of cultured keratinocytes, using a treatment with methyl-beta-cyclodextrin (MbetaCD) to extract cholesterol and a treatment with lovastatin to inhibit cholesterol neosynthesis.

Bacterial lipopolysaccharide induces proliferation of IL-6-dependent plasmacytoma cells by MAPK pathway activation.

Mouse plasmacytomas are appropriate models to study the biology of human multiple myeloma (MM). Growth of murine interleukin-6 (IL-6)-dependent hybridoma/plasmacytoma lines can be stimulated by bacterial lipopolysaccharides (LPS). However, the molecular mechanisms of this phenomenon are still not elucidated.