Michiya Matsusaki

Layer it on: Cellular multilayers were fabricated by preparing nanometer-sized extracellular matrix (ECM) films (6-nm thick) with fibronectin (FN) and gelatin on the surface of each cell layer. The four-layer cellular architecture was well organized and self-standing. Xenogenic human bilayer architectures similar to blood vessels were prepared by fabrication of the nanofilms on cell surfaces.

The acidic pH-sensitive controlled release of fibroblast growth factor-2 (FGF-2) from a biodegradable hydrogel without any denaturation of the FGF-2 was successfully performed by a combination of FGF-2 activity and acidic pH-sensitivity. We prepared semi-interpenetrating polymer network like hetero-gels (S72-netgels) composed of poly(gamma-glutamic acid) (gamma-PGA) and 72% sulfonated gamma-PGA (gamma-PGA-S72). S72-netgels including 36 mol % sulfonic acid (S72-netgel-36) showed wide acidic pH-se

Abstract Surface-functional bionanoparticles were prepared by self-assembling amphipathic poly(γ-glutamic acid) derivatives with a hydrophilic backbone and hydrophobic phenylalanine and leucine side groups. Poly(γ-glutamic acid) bearing phenylalanine nanospheres exhibited excellent water-dispersibility, surface functionality and appropriate size (200 nm) for medical use. Additive PEG conjugation assisted nanoparticle formation of leucine-grafted poly(γ-glutamic acid).

One of the key challenges in the field of bio-nanotechnology for drug delivery systems (DDS) is the development of nano- or micro-sized delivery carriers possessing both targeting functionalities for specific tissues or cells, and controlled release properties for encapsulated drug molecules, proteins and genes. Hollow capsules developed by layer-by-layer (LbL) assembly have attracted much attention over the past few years owing to their ability to be modified, their capacity to encapsulate a wi

Layer-by-layer (LbL) assembly has attracted much interest because of its ability to provide nanoscale control over film characteristics and because of a wide choice of available materials. The methods of LbL not only determine the process properties, but also directly affect film properties. In this review, we will discuss LbL methodologies that have been used in biomedical fields. Special attention is devoted to different properties arising from methods that allow for diverse biomedical applica

We developed a human skin equivalent (HSE) containing blood and lymph-like capillary networks using a cell coating technique, which is a rapid fabrication technology of three-dimensional cellular constructs by cell surface coating using layer-by-layer assembled nanofilms of extracellular matrices. The thickness of dermis consisting of normal human dermal fibroblasts was easily controlled from approximately 5 to 100 µm by altering the seeded cell number. Keratinocytes as a major cell population s

Surfaces with biological functionalities are of great interest for biomaterials, tissue engineering, biophysics, and for controlling biological processes. The layer-by-layer (LbL) assembly is a highly versatile methodology introduced 30 years ago, which consists of assembling complementary polyelectrolytes or biomolecules in a stepwise manner to form thin self-assembled films. In view of its simplicity, compatibility with biological molecules, and adaptability to any kind of supporting material

Abstract D,L ‐Lactic acid (DLLA) was polycondensed with 4‐hydroxycinnamic acid (4HCA), a derivative of cinnamic acid, to prepare a novel functional biodegradable polymer. The polymer was prepared using two different methods, the solvent method, which used acetic anhydride as the solvent, and the direct method. White and brown‐colored copolymers were obtained by these two methods, respectively. 1 H‐NMR spectroscopy and UV‐visible spectroscopy revealed that the double bond of 4HCA was almost compl

gamma-Poly(glutamic acid) (gamma-PGA), which is produced by Bacillus subtilis, was sulfonated using 2-aminoethane-1-sulfonic acid (taurine) in the presence of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (WSC) to give sulfonated gamma-PGA (gamma-PGA-sulfonate). From (1)H NMR spectroscopy and IR spectroscopy, it was confirmed that taurine was introduced to the side chain of gamma-PGA via an amide linkage. By altering the synthetic conditions, it was possible to control the content of sulfonate i

Alginate (ALG) hydrogels incorporating vascular endothelial growth factor (VEGF) were nano-coated with polyelectrolyte multilayer (PEM) films composed of chitosan (CT) and dextran sulfate (DEX) in order to control the VEGF release from the hydrogels. When non- and nano-coated ALG hydrogels containing VEGF were incubated in phosphate-buffered saline (PBS) at 37 degrees C for the prescribed times, the nano-coated hydrogels were stable, even after incubation for a week, whereas the non-coated hydro

Three-dimensional (3D)-layered blood vessel constructs consisting of human umbilical artery smooth muscle cells (SMCs) and human umbilical vascular endothelial cells (ECs) were fabricated by hierarchical cell manipulation, and their basic morphology, histology and blood compatibility were evaluated in relation to the EC layers. For the hierarchical cell manipulation, fibronectin-gelatin (FN-G) nanofilms were prepared on the surface of SMC layers to provide a cell adhesive nano-scaffold for the s