| POLYMERS Vol.61 No.8 |
| >> Chinese | >> English | >> Japanese | >> Korean |
COVER STORY
World of Nano-Particles for Medical Innovation |
| COVER STORY: Highlight Reviews |
| Internal Structures and Pharmacological Effects of Polymer Micelles | Isamu AKIBA, Masayuki YOKOYAMA |
| <Abstract>
Polymeric micelles were expected to be used as a carrier of drug delivery system
(DDS), and some DDS using polymer micelles have reached the clinical
trial state. To enhance the pharmacological effect in DDS, control of
size and drug-distribution of the carrier is important. In this paper,
we focus on the polymer micelles of polyethylene glycol-b-poly(amino
acid) derivative, including an overview about the size distribution and
drug control. Keywords: Polymer Micelle / DDS / Small-Angle X-Ray Scattering |
| Top of the Page▲ |
| Development of Bio-Nanocapsules (Nanocarriers Possessing Viral Infection Machinery) for in vivo Pinpoint DDS Carrier | Shun'ichi KURODA |
| <Abstract> Many viruses consisting of 50～100-nm particle structures can escape from the
capture by reticuloendothelial system, circulate in the body, adsorb
onto target tissues and cells, and finally enter into cells. These properties
of viruses indicate they are naturally occurring nanomachines, which
have evolved in bodies for long time. Forthcoming nanocarriers should
be developed by incorporating the virus-derived functions, i.e., stealth
activity, targeting activity, and cell-penetrating activity. In this
review, we describe a bio-nanocapsule, which is a hybrid of a human liver-specific
hepatitis B virus and liposomes. Keywords: Virus / Liposomes / Reticuloendothelial System / Stealth Activity / Targeting Activity / Cell-Penetrating Activity / Nanocarrier / Nanomedicine |
| Top of the Page▲ |
| Design of Artificial Gene Carrier Based on the Quantitative Comparison of Intracellular Trafficking with Adenovirus | Hidetaka AKITA, Hideyoshi HARASHIMA |
| <Abstract> A
category of biomedicine is now expanding from low-molecular drugs to
the recombinant protein, antibody, and nucleic acids (i.e. siRNA and
plasmid DNA). Development of a novel nanotechnology to target a specific
organelle is highly desired. Meanwhile, gene expression efficacy is rate-limited
by the multiple processes (i.e. cellular uptake, endosomal escape, cytoplasmic
transport and nuclear delivery). Adequate design to overcome these barriers
is a minimum requirement. As well as the intracellular trafficking, post-nuclear
delivery processes (i.e. transcription and translation) should be taken
into consideration. Especially, quantitative and mechanism-based information
on differences in transfection efficiency between viral and artificial
cationic vectors revealed that latter processes predominantly contributed
to the poor transfection efficacy in artificial ones in dividing cells.
In this review, we give an overview of our previous studies on the quantitative
comparison of intracellular events between cationic vector and adenovirus. Also, we will summarize and discuss about possible
designs for controlling the intracellular trafficking and post-nuclear
delivery processes. Keywords: Adenovirus / Artificial Vector / Gene Therapy / Intracellular Trafficking |
| Top of the Page▲ |
| COVER STORY: Topics and Products |
| Therapeutic Technique Mediated by Photothermal Effect of Gold Nanoparticles | Takuro NIIDOME, Yasuro NIIDOME |
| <Abstract> Gold
nanoparticles that have an absorption band at near infrared region have
attracted much attention. Since near infrared light can penetrate deeply
into tissues, they can be used not only as heating device for hyperthermia
but also as a control device of drug release from the gold surface. It
will be a powerful medical device in the next generation. Keywords: Gold Nanoparticle / Photothermal Effect / Infrared Light / Hyperthermia / Cancer Therapy / Drug Delivery |
| Top of the Page▲ |
| TRX, A Novel Cationic Lipid for Transfection having an Amidine Headgroup was Developed and Its SAXS Profiles Complexed with DNA | Kazunori KOIWAI, Kazuhiro SHIMIZU, Masashi ISOZAKI |
| <Abstract> Cationic
lipids are widely used for transfection of cultured cells, and are being
investigated for in vivo gene transfer vectors. With the objective of
developing new gene transfer vehicles, cationic amphiphiles have been
sythesized and used to formulate small unilamellar vesicles with co-lipids
(DOPE and DLPC). Amphiphatic compounds demonstrating an excellent performance
in transfection are conjugates of amidinobenzene linked through a ether
bond to alkyl substitutions (denoted by TRX). Figure 4 presents SAXS profiles when TRX with co-lipids was mixed with different density of PBS. At the low density of PBS, the SAXS profiles show no peak, and as the density of PBS was increased, the SAXS profiles show three distinctive peaks. The relation of these peaks satisfies the ratio of 1:√3:2, indicating presence of the hexagonally packed cylinders. It is clearly evident that DNA was packed between cylinder and cylinder in the TRX with co-lipids and DNA complex. Keywords: Cationic Lipids / TRX / Transfection / DNA / SAXS / Cylinder |
| Top of the Page▲ |
| Thermoresponsive Polymeric Micelles for Intelligent DDS | Masamichi NAKAYAMA, Teruo OKANO |
| <Abstract> Nano-scale
polymeric micelles possessing thermoresponsive coronas are formed via
the multi-molecular assemblies of poly(N-isopropylacrylamide)-based block
copolymers in aqueous media. Thermoresponsive micelles show the enhanced
release of incorporated drugs and internalization inside cells through
the temperature-induced phase transition of thermoresponsive coronas.
These unique functions are promising to be utilized for smart drug targeting. Keywords: Drug Delivery System / Poly(N-isopropylacrylamide) / Thermoresponsive Polymer / Block Copolymer / Polymeric Micelle / Targeting |
| Top of the Page▲ |
| Nanocarriers for Clinical treatments: Peptsome and Lactosome | Shunsaku KIMURA |
| <Abstract> Nanocarriers
are expected to be applied for DDS as stealth carriers of signal agents,
clinical drugs, and targeting ligands. Nanocarriers therefore have to
be equipped with properties of escape from kidney excretion and liver
excretion, evasion from the immune system and the complement system,
and consequently prolonged in vivo blood clearance time. Peptosome and
lactosome, which are self-assemblies of helices, satisfy these requirements
by precise molecular design and are expected to be applied for translational
researches. Keywords: Nanocarriers / Peptosome / Lactosome / Imaging / DDS / Immune System / EPR Effect / ABC Phenomenon |
| Top of the Page▲ |
| Front-Line Polymer Science |
| Recent Advances in Fast Photoswitchable Molecules | Jiro ABE |
| <Abstract> Considerable
interest has been focused on organic photochromic materials that change
their color upon irradiation with light; the photogenerated species can
be reversed to the initial species either thermally or by subsequent
irradiation with a specific wavelength of light. In particular, thermally
reversible photochromic molecules offer the opportunity to change and
reset the molecular properties by simply turning a light source on and
off. In this review, the brief history of the field is reviewed, and
the key features characterizing fast photochromic molecules are described
with representative papers. Keywords: Photochromism / Molecular Switches / HABI / Bridged-Imidazole Dimer |
| Polymer Science and I: A Personal Account |
| Interesting and Useful; Is Both Possible? | Kazunori SUGIYASU |
| <Abstract> When I started my own research projects, I decided to synthesize “interesting” molecules; however, since then, I have been wondering what molecules are “interesting” at all and how they can be “useful” as well. |
| Top of the Page▲ |
| Top of the Page▲ |
| Copyright(C) 2012 The Society of Polymer Science, Japan All Rights Reserved. |