An epidermal growth factor derivative with binding affinity for hydroxyapatite and titanium surfaces.

An epidermal growth factor (EGF) derivative with affinity for apatite and titanium surfaces was designed using a peptide moiety derived from salivary statherin, a protein that adheres to hydroxyapatite. Since the active sequence has two phosphoserine residues, the EGF derivative was prepared by organic synthesis, and a 54 residue peptide was successfully prepared using this method. Circular dichroism spectra indicated that the conformation of EGF was not significantly altered by the addition of the affinity peptide sequence and the mitogenic activity was only slightly reduced when compared with the wild-type protein.

Recombinant hBMP4 incorporated with non-canonical amino acid for binding to hydroxyapatite.

A novel growth factor containing non-canonical amino acids was designed and synthesized to enhance the binding to hydroxyapatite (HA). The designed protein was human bone morphogenetic protein 4 (hBMP4) incorporating diphosporylated serines (pSpS) that was found in salivary protein statherin and was reported to be responsible for binding to HA. Recombinant hBMP4 and a short peptide sequences containing pSpS were ligated by enzymatice reaction of sortase A, which exchanges the terminal amino acids of two polypeptides.

Visible light-induced crosslinkable gelatin.

A novel visible light-crosslinkable porcine gelatin was prepared for gelation and micropatterning. The preparation employed a photo-oxidation-induced crosslinking mechanism. First, furfuryl groups were incorporated into the gelatin.

A photoimmobilizable sulfobetaine-based polymer for a nonbiofouling surface.

A novel photoreactive polymer containing sulfobetaine polar groups was prepared by copolymerization of two kinds of methacrylic acids with sulfobetaine and azidoaniline. The polymer was photoimmobilized on polyester and polystyrene surfaces. Its effects on surface modification were investigated from its interactions with water, proteins and cells.

Surface coating with a thermoresponsive copolymer for the culture and non-enzymatic recovery of mouse embryonic stem cells.

A thermoresponsive substrate based on a triblock copolymer, poly(N-isopropylacrylamide)-block-poly[(R)-3-hydroxybutyrate]-block-poly(N-isopropylacrylamide) (PNIPAAm-PHB-PNIPAAm), co-coated with gelatin, was developed for the culture and non-enzymatic recovery of mouse embryonic stem cells. After culture, the cells could be detached by cooling at 4 degrees C for 20 min without trypsin digestion. The embryonic stem cells remained undifferentiated after culture on the gelatin/copolymer-coated surfaces, similar to standard culture techniques.

A chimeric epidermal growth factor with fibrin affinity promotes repair of injured keratinocyte sheets.

The aim of the present study is to create a novel chimeric protein of epidermal growth factor (EGF) with fibrin affinity and demonstrate its potential for repairing injured tissues by immobilization to fibrin. The chimeric protein (FBD-EGF) was produced by the fusion of the fibronectin fibrin-binding domain (FBD) to EGF. It showed dose-dependent binding to fibrin and its binding was stable for at least 7days, while native EGF showed little affinity.

Surface modification of plastic, glass and titanium by photoimmobilization of polyethylene glycol for antibiofouling.

Photoreactive poly(ethylene glycol) (PEG) was prepared and the polymer was photoimmobilized on organic, inorganic and metal surfaces to reduce their interaction with proteins and cells. The photoreactive PEG was synthesized by co-polymerization of methacrylate-PEG and acryloyl 4-azidobenzene. Surface modification was carried in the presence and the absence of a micropatterned photomask.

Modification of the titan surface with photoreactive gelatin to regulate cell attachment.

Titan (TiO2) was modified with photoreactive gelatin in order to regulate the attachment of cells. Photoreactive gelatin, which was synthesized by the coupling reaction of gelatin with N-(4-azidobenzoyloxy) succinimide, was immobilized onto the n-octadecyltrimethoxysilane (ODS)-TiO2 or TiO2 surface by ultraviolet irradiation both in the absence and presence of a photo mask. In the absence of a photo mask, the modified titan surface was analyzed by measuring water contact angles and X-ray photoelectron spectroscopy (XPS).

Functional analysis of chick ONT1 reveals distinguishable activities among olfactomedin-related signaling factors.

The Olfactomedin family is a relatively new class of extracellular proteins. Two family members have been shown to play roles in the early development of ectodermal tissues: Noelin enhances neural crest generation in chick and Tiarin promotes dorsal neural specification in Xenopus. In this study, we introduce a novel member of the Olfactomedin family, ONT1.

Gene disruption/knock-in analysis of mONT3: vector construction by employing both in vivo and in vitro recombinations.

We report the isolation, spatial/temporal expression and gene disruption phenotype of the mouse ONT3 (mONT3) gene, which encodes a novel secreted signaling protein belonging to the Olfactomedin/Noelin/Tiarin family. During early embryogenesis, mONT3 is detected in the proximal region of the allantois on embryonic day (E) 7.25, in the lateral plate mesoderm on E 8.

Dorsalization of the neural tube by Xenopus tiarin, a novel patterning factor secreted by the flanking nonneural head ectoderm.

We have isolated a novel secreted dorsalizing factor of the neural tube, Xenopus Tiarin, which belongs to the olfactomedin-related family. Tiarin expression starts at the late gastrula stage in the nonneural ectoderm adjacent to the anterior neural plate. Overexpression of Tiarin in the embryo causes expansion of dorsal neural markers and suppression of ventral markers.