A silk elastin-like protein (SELP) is an artificial compound composing silk fibroin-like and elastin-like tandem repeats. The objective of this study is to evaluate the SELP effect on the migration, proliferation, and proteins production of L929 mouse fibroblasts. Upon culturing with different concentrations of SELP, the cells migration and their collagen production significantly enhanced in the SELP concentrations from 10(-3) to 10 μg/ml. However, irrespective of the SELP concentration, no difference in the production of fibronectin, basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), and stromal cell-derived factor 1α (SDF-1α) was observed. When the migration of mouse peritoneal macrophages by SELP was evaluated, significant enhancement of macrophages migration was observed in any concentration. It is concluded that the SELP has a potential to promote the migration of fibroblasts and macrophages, and the fibroblast collagen production.

Silk-elastin is a recombinant protein polymer with repeating units of silk and elastin blocks. This novel wound healing promoting material has the ability to self-assemble from a liquid to a gel. We have already reported that an aqueous solution of silk-elastin has the potential to accelerate wound healing; however, there are several problems in applying silk-elastin in the clinical setting. To solve these problems, we developed a silk-elastin sponge that is easy to use in the clinical setting. In the present study, we examined whether the wound healing effect of the silk-elastin sponge is equal to the aqueous solution of silk-elastin in vivo. The granulation tissue formation promoting effect of the silk-elastin sponge was equal to that of the aqueous solution the silk-elastin, as after application to the wound surface, the sponge was absorbed and dissolved by the exudate. At body temperature the silk-elastin then formed temperature gel. The silk-elastin gel that was obtained contained abundant cytokines from the exudate. We believe that silk-elastin sponge can be applied to various wounds that are difficult to treat with the aqueous solution.

The objective of this study is to evaluate the effect of an artificial silk-elastin-like protein (SELP) on the adhesion and apoptotic behavior of cells. When MC3T3-E1 cells were cultured on dishes coated with different concentrations of SELP, the cells adhesion was suppressed with the increasing coating concentration. As controls, the coating with fibronectin enhanced the number of cells adhered in the concentration dependent manner. The poly (vinyl alcohol) (PVA) and agarose coating suppressed the cell adhesion. Elastin did not affect the cell adhesion behavior. The shape of cells cultured on the SELP, PVA, and agarose-coated dishes was spherical and spreaded cells were observed on the SELP-and fibronectin-coated ones. The level of caspase 3 and 9 was evaluated. The level was significantly high for the PVA-and agarose-coated dishes compared with non-coated dishes, whereas it was low for the fibronectincoated ones. The level was decreased with an increase in the concentration of SELP coated. The number of cells free of annexin V activity for the SELP group as low as that for the fibronectin group. The cell number was high for the PVA and agarose groups. The actin filaments were detected for the SELP-coated dishes, in remarked contrast to the PVA-coated ones. Pretreatment with the antibody of integrin αV or α5 significantly decreased the caspase 3 level for cells cultured on the SELP-coated dishes. It is concluded that the SELP has an unique property which allows cells to suppress their adhesion, but not to induce their apoptosis.

ProNectin F (PnF) was chemically modified by introducing some functional groups to prepare various derivatives of primary amino (PnF-N₁), tertiary amino (PnF-N₃), quaternary ammonium (PnF-N₄), carboxyl (PnF-COOH) and sulfonyl groups (PnF-SO₃H). When C3H10T1/2 cells were cultured on non-treated dishes coated with the derivatives, the number of mesenchymal cells attached to the culture dishes increased for the coating with PnF-COOH and PnF-SO₃H, even at their low adsorption amount. The cytotoxicity was high for the coating of PnF-N₁ and PnF-N₄ compared with that of the PnF-N₃, PnF-COOH and PnF-SO₃H. The treatment with integrin α5 and αV antibodies suppressed the cell attachment to the dishes coated with PnF-COOH and PnF-SO₃H. The phosphorylation of extracellular signal-regulated kinase (ERK) was upregulated for cells attached to the dishes coated with PnF-COOH and PnF-SO₃H, indicating their enhanced proliferation. It is concluded that the chemical derivatization of PnF enhanced the ability of cell attachment and proliferation.

No abstract