The development of stimuli responsive polymers has progressed significantly with novel preparation techniques, which has allowed access to new materials with unique properties. Dual thermoresponsive (double temperature responsive) block copolymers are particularly of interest as their properties can change depending on the lower critical solution temperature (LCST) or upper critical solution temperature (UCST) of each segment. For instance, these block copolymers can change from being hydrophilic, to amphiphilic or to hydrophobic simply by changing the solution temperature without any additional chemicals and the block copolymers can change from being fully solubilized to self-assembled structures to macroscopic aggregation/precipitation. Based on the unique solution properties, these dual thermo-responsive block copolymers are expected to be suitable for biomedical applications. This review is divided into three parts; LCST-LCST types of block copolymers, UCST-LCST types of block copolymers, and their potential as biomedical applications.

Inactivated Hemagglutinating Virus of Japan Envelope (HVJ-E) was immobilized on electrospun nanofibers of poly(ε-caprolactone) by layer-by-layer (LbL) assembly technique. The precursor LbL film was first constructed with poly-L-lysine and alginic acid via electrostatic interaction. Then the HVJ-E particles were immobilized on the cationic PLL outermost surface. The HVJ-E adsorption was confirmed by surface wettability test, scanning laser microscopy, scanning electron microscopy, and confocal laser microscopy. The immobilized HVJ-E particles were released from the nanofibers under physiological condition. In vitro cytotoxic assay demonstrated that the released HVJ-E from nanofibers induced cancer cell deaths. This surface immobilization technique is possible to perform on anti-cancer drug incorporated nanofibers that enables the fibers to show chemotherapy and immunotherapy simultaneously for an effective eradication of tumor cells in vivo.

Article Aminopeptidase N (CD13, EC 3.4.11.2) Occurs on the Surface of Resting and Concanavalin A-Stimulated Lymphocytes was published on January 1, 1993 in the journal Biological Chemistry (volume 374, issue 1-6).

Our study reports a versatile immobilization method of Hemagglutinating Virus of Japan Envelope (HVJ-E) for the generation of viral-mimetic surfaces for hormone resistant prostate cancer cell isolation. HVJ-E has recently attracted much attention as a new type of therapeutic material because hormone resistant prostate cancer cells such as PC-3 cells possess the HVJ-E receptors, GD1a. The HVJ-E was successfully immobilized on precursor films composed of poly-L-lysine and alginic acid via layer-by-layer assembly without changing the biological activity. The monolayer adsorption of HVJ-E particles was confirmed by quartz crystal microbalance, fluorescent and atomic force microscopy analyses. By developing the HVJ-E coating with an affinity based cell trap within a glass capillary tube, we are able to gently isolate PC-3 from LN-Cap cells that represent adenocarcinoma without compromising cell viability. We achieved approximately 100% cell separation efficiency only by 60 seconds of flowing. We believe that the proposed technique offers significant promise for the creation of a hormone resistant cancer cell trap on a broad range of materials.

For reducing side effects and improvement of swallowing, we studied the encapsulation of activated carbon formulations with a hollow-type spherical bacterial cellulose (HSBC) gel using two kinds of encapsulating methods: Methods A and B. In Method A, the BC gelatinous membrane was biosynthesized using Komagataeibacter xylinus (K. xylinus) at the interface between the silicone oil and cell suspension containing activated carbon. In Method B, the bacterial cellulose (BC) gelatinous membrane was formed at the interface between the cell suspension attached to the alginate gel containing activated carbon and the silicone oil. After the BC gelatinous membrane was biosynthesized by K. xylnus, alginate gel was removed by soaking in a phosphate buffer. The activated carbon encapsulated these methods could neither pass through the BC gelatinous membrane of the HSBC gel nor leak from the interior cavity of the HSBC gel. The adsorption ability was evaluated using indole, which is a precursor of the uremic causative agent. From curve-fitting, the adsorption process followed the pseudo-first-order and intra-particle diffusion models, and the diffusion of the indole molecules at the surface of the encapsulated activated carbon within the HSBC gel was dominant at the initial stage of adsorption. It was observed that the adsorption of the encapsulated activated carbon by the intraparticle diffusion process became dominant with longer adsorption times.