The absorption of 14C-labelled 2,4-diaminoanisole together with its reaction products was investigated after application to the skin of rats. 2,4-Diamino[14C]anisole was applied as an ingredient of three different hair-dyeing formulations using procedures approximating to realistic conditions of use. Percutaneous absorption of the compound ranged from 0.26 to 1.1% of the administered dose, according to the formulation used. Elimination occurred mainly in the urine, with a smaller proportion in the faeces. Very small amounts were detected in the expired air. Complementary investigations involving subcutaneous or oral application of a solution of 2,4-diamino[14C]anisole. 2HCl showed that radioactivity was rapidly eliminated in the urine and faeces. Biliary excretion was demonstrated after oral administration.
Laminins are major components of all basement membranes surrounding nerve or vascular tissues. In particular laminin-111, the prototype of the family, facilitates a large spectrum of fundamental cellular responses in all eukaryotic cells. Laminin-111 is a biomaterial frequently used in research, however it is primarily isolated from non-human origin or produced with time-intensive recombinant techniques at low yield.Here, we describe an effective method for isolating laminin-111 from human placenta, a clinical waste material, for various tissue engineering applications. By extraction with Tris-NaCl buffer combined with non-protein-denaturation ammonium sulfate precipitation and rapid tangential flow filtration steps, we could effectively isolate native laminin-111 within only 4 days. The resulting material was biochemically characterized using a combination of dot blot, SDS-PAGE, Western blot and HPLC-based amino acid analysis. Cytocompatibility studies demonstrated that the isolated laminin-111 promotes rapid and efficient adhesion of primary Schwann cells. In addition, the bioactivity of the isolated laminin-111 was demonstrated by (a) using the material as a substrate for outgrowth of NG 108-15 neuronal cell lines and (b) promoting the formation of interconnected vascular networks by GFP-expressing human umbilical vein endothelial cells.In summary, the isolation procedure of laminin-111 as described here from human placenta tissue, fulfills many demands for various tissue engineering and regenerative medicine approaches and therefore may represent a human alternative to various classically used xenogenic standard materials.
DOI : 10.1007/978-981-13-0947-2_1 Anahtar Kelimeler :
Laminin-111, NG 108-15, Placenta, Schwann cells, Vasculogenesis