Impact of collagen crosslinking on the second harmonic generation signal and the fluorescence lifetime of collagen autofluorescence.

Background/purpose: Collagen is the major structural protein of the skin and its crosslinks are essential for its mechanical stability. In photodamaged skin, a decrease of the mature collagen crosslink histidinohydroxylysino-norleucine was reported. In this study, we investigated the consequences and measurability of the reduced crosslinking.

Folic acid and creatine improve the firmness of human skin in vivo.

Background: The decrease in firmness is a hallmark of skin aging. Accelerated by chronic sun exposure, fundamental changes occur within the dermal extracellular matrix over the years, mainly impairing the collagenous network.

Aims: Based on the qualitative and quantitative assessment of skin firmness, in vitro and in vivo studies were carried out to elucidate the effects of topical folic acid and creatine to counteract this age-dependent reduction in the amount of collagen.

Evaluation of cartilage specific matrix synthesis of human articular chondrocytes after extended propagation on microcarriers by image analysis.

Background: Cell-based technologies for the repair of cartilage defects usually rely on the expansion of low numbers of chondrocytes isolated from biopsies of healthy cartilage. Proliferating chondrocytes are known to undergo dedifferentiation characterized by downregulation of collagen type II and proteoglycan production, and by upregulation of collagen type I synthesis. Re-expression of cartilage specific matrix components by expanded chondrocytes is therefore critical for successful cartilage repair.