Kyushu University · Materials Science
Professor Akihiro Kishimura's research lab specializes in the design and application of polyion complex-based nanomaterials, particularly for biomedical and drug delivery systems. The lab focuses on developing stimuli-responsive vesicles (PICsomes) that can selectively accumulate in tumor tissues and release their cargo in response to environmental triggers such as pH changes. Key research directions include the fabrication of enzyme-loaded nanoreactors, siRNA delivery systems, and functional organogels with tunable optical properties through metallophilic interactions. The lab also explores the use of size-tunable nanocarriers to understand and control biodistribution in vivo.
Figures are computed from collected data and may differ slightly.
A trinuclear Au(I) pyrazolate complex bearing long alkyl chains (1) in hexane self-assembles via a Au(I)-Au(I) metallophilic interaction, to form a red-luminescent organogel (lambda(em) = 640 nm, lambda(ext) = 284 nm). Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis of an air-dried gel with 1 show the presence of heavily entangled fibers, each consisting of a rectangularly packed columnar assembly of 1. Doping of the organogel with a small amount of Ag(+) results in a blu
Take your PIC: Biologically active polyion complex vesicles (PICsomes) with encapsulated myoglobin (Mb) can be prepared by the self-assembly of a pair of oppositely charged block ionomers with polyethylene glycol (PEG) segments (see picture; metMb: metmyoglobin). The loaded Mb maintains reversible oxygenation even in the presence of trypsin.
The design and construction of nanoreactors are important for biomedical applications of enzymes, but lipid- and polymeric-vesicle-based nanoreactors have some practical limitations. We have succeeded in preparing enzyme-loaded polyion complex vesicles (PICsomes) through a facile protein-loading method. The preservation of enzyme activity was confirmed even after cross-linking of the PICsomes. The cross-linked β-galactosidase-loaded PICsomes (β-gal@PICsomes) selectively accumulated in the tumor
Selective disposition of nanocarriers into target tissue is an essential issue in drug delivery. Critical size of nanocarriers (∼150 nm) discriminating the permeability into normal and tumor tissues was determined by the use of size-tunable, polyion complex hollow vesicles (PICsome) as a ruler.
Vesicular polyion complexes (PICs) were fabricated through self-assembly of rigid cylindrical molecules, small interfering RNAs (siRNAs), with flexible block catiomers of poly(ethylene glycol) (2 kDa) and cationic polyaspartamide derivative (70 units) bearing a 5-aminopentyl side chain. 100 nm-sized siRNA-assembled vesicular PICs, termed siRNAsomes, were fabricated in specific mixing ranges between siRNA and block catiomer. The siRNAsome membrane was revealed to consist of PIC units fulfilling a
The acidic pH-sensitivity of polyion complex vesicles (PICsomes) was investigated, using dynamic light scattering (DLS) and confocal laser scanning microscopy (CLSM). PICsomes showed pH-dependent and reversible structural transition, and also underwent a change in permeability by sensing acidic pH. Increased membrane permeability at the pH corresponding to cellular endosomes may be useful for future applications of PICsomes as a delivery vehicle of biologically active compounds to intracellular
Abstract The design and construction of nanoreactors are important for biomedical applications of enzymes, but lipid‐ and polymeric‐vesicle‐based nanoreactors have some practical limitations. We have succeeded in preparing enzyme‐loaded polyion complex vesicles (PICsomes) through a facile protein‐loading method. The preservation of enzyme activity was confirmed even after cross‐linking of the PICsomes. The cross‐linked β‐galactosidase‐loaded PICsomes (β‐gal@PICsomes) selectively accumulated in t
Schutz für Proteine: Biologisch aktive Vesikel aus polyionischen Komplexen (PICsome) mit darin verkapseltem Myoglobin (Mb) wurden durch Selbstorganisation von entgegengesetzt geladenen Blockionomeren mit Polyethylenglycol(PEG)-Segmenten erhalten (siehe Bild; metMb: Metmyoglobin). Die Mb-Proteine halten eine reversible Oxygenierung aufrecht, auch in Gegenwart von Trypsin. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2001/2007/z701776_s.
Although hollow microscopic capsules have a variety of potential biomedical applications, reports of organic-solvent-free methods for their preparation are rather limited. Herein, a novel approach is demonstrated for organic-solvent-free preparation of giant unilamellar vesicles utilizing the unique response of polyion complexes (PICs) to changes in additive salt concentration. A microfluidic device consisting of a main channel bearing side pockets that work as microscale reaction chambers is de
For the simultaneous delivery of antisense oligonucleotides and their effector enzymes into cells, nanosized vesicular polyion complexes (PICs) were fabricated from oppositely charged polyion pairs of oligonucleotides and poly(ethylene glycol) (PEG)-<i>b</i>-polypeptides. First, the polyion component structures were carefully designed to facilitate a multimolecular (or secondary) association of unit PICs for noncovalent (or chemical cross-linking-free) stabilization of vesicular PICs. Chemically
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