Genipin cross-linked fibrin hydrogels for in vitro human articular cartilage tissue-engineered regeneration.

Our objective was to examine the potential of a genipin cross-linked human fibrin hydrogel system as a scaffold for articular cartilage tissue engineering. Human articular chondrocytes were incorporated into modified human fibrin gels and evaluated for mechanical properties, cell viability, gene expression, extracellular matrix production and subcutaneous biodegradation. Genipin, a naturally occurring compound used in the treatment of inflammation, was used as a cross-linker.

Modulation of endothelin-1 in normal human keratinocytes by UVA1/B radiations, prostaglandin E2 and peptidase inhibitors.

In the skin, keratinocytes synthesize and secrete endothelin-(ET-1), a potent vasoconstrictor peptide which acts also as a growth factor for most skin cells. The aim of the study was to test the effects of UVA1 and the associations UVA1/B on the expression of ET-1 in normal human keratinocytes and to determine whether exogenously added prostaglandin E2 (PGE2) regulated ET-1 expression. As ET-1 is susceptible to degradation, we also evaluated whether ET-1 secretion was modulated by peptidase inhibitors.

Transforming growth factor-beta1 and ultraviolet A1 radiation increase production of vascular endothelial growth factor but not endothelin-1 in human dermal fibroblasts.

Background: Normal and dysregulated wound healing involves fibroblast activation and angiogenesis, in which polypeptide factors such as transforming growth factor (TGF)-beta, vascular endothelial growth factor (VEGF) and endothelin-1 (ET-1) play an important part. Ultraviolet (UV) A1 (365 nm) has recently received attention as a possible treatment for some dermal fibrotic disorders.

Objectives: The aim of this study was to evaluate the effects of TGF-beta1 and UVA1 radiation, as well as that of cobalt chloride, reported to mimic hypoxia both in vivo and in vitro, on the expression of VEGF and ET-1 by cultured human dermal fibroblasts.