Investigating the effect of the micelle structures of block and random copolymers on dye solubilization.

To elucidate the correlation between dye solubilization into micelles and their core-shell aggregated structure, the structures of block and random copolymer micelles were characterized. The block copolymer micelles exhibited a higher dye solubilization capacity which correlated with their core volume, clear core-shell contrast and slow solubilization rate.

Low-adhesion and low-swelling hydrogel based on alginate and carbonated water to prevent temporary dilation of wound sites.

Hydrogel-based wound dressings have been developed for rapid wound healing; however, their adhesive properties have not been adequately investigated. Excessive adhesion to the skin causes wound expansion and pain when hydrogels absorb exudates and swell at wound sites. Herein, we developed a low-adhesion and low-swelling hydrogel dressing using alginate, which is non-adhesive to cells and skin tissue, CaCO3, and carbonated water. The alginate/CaCO3 solution rapidly formed a hydrogel upon the addition of carbonated water, and the CO2 in the hydrogel diffused into the atmosphere, preventing acidification and obtaining a pH value suitable for wound healing. Remarkably, the skin adhesion and swelling of the hydrogel were 11.9- to 16.5-fold and 1.9-fold lower, respectively, than those of clinical low-adhesion hydrogel dressings. In vivo wound-healing tests in mice demonstrated its therapeutic efficacy, and the prepared hydrogel prevented temporary wound dilation during early healing. These results illustrate the importance of controlling skin adhesion and swelling in wound dressings and demonstrate the potential clinical applications of this wound-friendly hydrogel dressing.

Three-dimensional co-culture model employing silica nonwoven fabrics to enhance cell-to-cell communication of paracrine signaling between hepatocytes and fibroblasts.

The realization that soluble factors secreted by heterotypic cells play an importanta role in paracrine signaling, which facilitates intercellular communication, enabled the development of physiologically relevant co-culture models for drug screening and the engineering of tissues, such as hepatic tissues. The most crucial issues confronting the use of conventional membrane inserts in segregated co-culture models that are used to study paracrine signaling between heterotypic cells have been identified as long-term viability and retention of cell-specific functions, especially when isolated primary cells are used. Herein, we present an in vitro segregated co-culture model consisting of a well plate incubated with rat primary hepatocytes and normal human dermal fibroblasts which were segregated using a membrane insert with silica nonwoven fabric (SNF) on it. SNF, which mimics a physiological environment much more effectively than a two-dimensional (2D) one, promotes cell differentiation and resultant paracrine signaling in a manner that is not possible in a conventional 2D culture, owing to high mechanical strength generated by its inorganic materials and interconnected network structure. In segregated co-cultures, SNF clearly enhanced the functions of hepatocytes and fibroblasts, thereby showing its potential as a measure of paracrine signaling. These results may advance the understanding of the role played by paracrine signaling in cell-to-cell communication and provide novel insights into the applications of drug metabolism, tissue repair, and regeneration.

Physicochemical Properties of Egg-Box-Mediated Hydrogels with Transiently Decreased pH Employing Carbonated Water.

Anionic polysaccharides, including low-methoxy (LM) pectin, are extensively used in biomaterial applications owing to their safety, biocompatibility, and feasibility in constructing supramolecular assemblies by forming egg-box structures with divalent cations. Mixing an LM pectin solution with CaCO3 spontaneously forms a hydrogel. The gelation behavior can be controlled by adding an acidic compound to change the solubility of CaCO3. CO2 is used as the acidic agent and can be easily removed after gelation, thereby reducing the acidity of the final hydrogel. However, CO2 addition has been controlled under varied thermodynamical conditions; therefore, specific CO2 effects on gelation are not necessarily visualized. To evaluate the CO2 impact on the final hydrogel, which would be extended to control hydrogel properties further, we utilized carbonated water to supply CO2 into the gelation mixture without changing its thermodynamic conditions. The addition of the carbonated water accelerated gelation and significantly increased the mechanical strength, promoting cross-linking. However, the CO2 volatilized into the atmosphere, and the final hydrogel became more alkaline than that without the carbonated water, probably because a considerable amount of the carboxy group was consumed for cross-linking. Moreover, when aerogels were prepared from the hydrogels with carbonated water, they exhibited highly ordered networks of elongated porosity in scanning electron microscopy, proposing an intrinsic structural change by CO2 in the carbonated water. We also controlled the pH and strength of the final hydrogels by changing the CO2 amounts in the carbonated water added, thereby validating the significant effect of CO2 on hydrogel properties and the feasibility of using carbonated water.

Nanofabrication Technologies to Control Cell and Tissue Function in Three-Dimension.

In the 2000s, advances in cellular micropatterning using microfabrication contributed to the development of cell-based biosensors for the functional evaluation of newly synthesized drugs, resulting in a revolutionary evolution in drug screening. To this end, it is essential to utilize cell patterning to control the morphology of adherent cells and to understand contact and paracrine-mediated interactions between heterogeneous cells. This suggests that the regulation of the cellular environment by means of microfabricated synthetic surfaces is not only a valuable endeavor for basic research in biology and histology, but is also highly useful to engineer artificial cell scaffolds for tissue regeneration. This review particularly focuses on surface engineering techniques for the cellular micropatterning of three-dimensional (3D) spheroids. To establish cell microarrays, composed of a cell adhesive region surrounded by a cell non-adherent surface, it is quite important to control a protein-repellent surface in the micro-scale. Thus, this review is focused on the surface chemistries of the biologically inspired micropatterning of two-dimensional non-fouling characters. As cells are formed into spheroids, their survival, functions, and engraftment in the transplanted site are significantly improved compared to single-cell transplantation. To improve the therapeutic effect of cell spheroids even further, various biomaterials (e.g., fibers and hydrogels) have been developed for spheroid engineering. These biomaterials not only can control the overall spheroid formation (e.g., size, shape, aggregation speed, and degree of compaction), but also can regulate cell-to-cell and cell-to-matrix interactions in spheroids. These important approaches to cell engineering result in their applications to tissue regeneration, where the cell-biomaterial composite is injected into diseased area. This approach allows the operating surgeon to implant the cell and polymer combinations with minimum invasiveness. The polymers utilized in hydrogels are structurally similar to components of the extracellular matrix in vivo, and are considered biocompatible. This review will provide an overview of the critical design to make hydrogels when used as cell scaffolds for tissue engineering. In addition, the new strategy of injectable hydrogel will be discussed as future directions.

Enhanced burst strength of catechol groups-modified Alaska pollock-derived gelatin-based surgical adhesive.

Aortic anastomotic leak is a potentially fatal complication that can occur after treatment of aortic dissection or aneurysm. Several surgical adhesives have been used to prevent this complication, but all have problems with regard to tissue adhesion or biocompatibility. In the present study, we developed a surgical adhesive composed of boric acid-protected catechol groups-modified Alaska pollock-derived gelatin (Cat-ApGltn) and a poly(ethylene glycol)-based crosslinker (4S-PEG). By avoiding oxidation of catechol groups using boric acid, resulting Cat-ApGltn adhesive formed a strong hydrogel by double crosslinking: chemical crosslinking by 4S-PEG, and chemical and physical crosslinking by the catechol groups. The catechol groups modification contributed to increased bulk strength and decreased gelation time/swelling ratios. The Cat-ApGltn adhesive, in which 7.8 mol% of the amino groups of the original ApGltn (Org-ApGltn) were modified with catechol groups, demonstrated 2.3 times higher burst strength compared with the Org-ApGltn adhesive, and 3.9 times higher burst strength compared with a commercial fibrin adhesive. When the Cat-ApGltn adhesive was implanted subcutaneously into rats, it induced only weak inflammation similar to that induced by the Org-ApGltn adhesive, and was completely degraded within 2 months. Therefore, the Cat-ApGltn adhesive has great potential for use in the field of cardiovascular surgery.

Controlled polymerization of metal complex monomers - fabricating random copolymers comprising different metal species and nano-colloids.

Acrylate monomers with metal complexes were designed to build polymer metal complexes. The ideal copolymerization of monomers with zinc and platinum was performed to obtain random copolymers with a feeding metal composition. The successful nano-colloid preparation from the polymers further highlighted the potential of the method for building multimetallic materials.

Accelerated Redox Reaction of Hydrogen Peroxide by Employing Locally Concentrated State of Copper Catalysts on Polymer Chain.

Copper complexes act as catalysts for redox reactions to generate reactive oxygen species that destroy biomolecules and, therefore, are utilized to design drugs including antitumor and antibacterial medicines. Especially, catalytic reaction for hydrogen peroxide decomposition is important because it includes the process for generating highly toxic hydroxyl radical, i.e., Fenton-like reaction. Considering that multicoppers/hydrogen peroxide species are the important intermediates for the redox reaction, herein a polymer having copper complexes in the side chains is designed to facilitate the formation of the intermediates by building locally concentrated state of the copper complexes. The polymer increases their catalytic activities for hydrogen peroxide decomposition and promotes reactive oxygen species' generation, eventually leading to higher antibacterial activity. This reveals the virtue of building a locally concentrated state of catalysts on polymers toward drug design with low amounts of transition metals.

Potentiometric Determination of Circulating Glycoproteins by Boronic Acid End-Functionalized Poly(ethylene glycol)-Modified Electrode.

Despite tremendous complexity in glycan structure, sialic acid (SA) provides an analytically accessible index for glycosylation, owing to its uniquely anionic nature and glycan-chain terminal occupation. Taking advantage of boronic acid (BA) based SA-recognition chemistry, we here demonstrate a label-free, no enzymatic, potentiometric determination of fetuin, a blood-circulating glycoprotein implicated in physiological and various pathological states. A phenylboronic acid (PBA) ω-end-functionalized poly(ethylene glycol) (PEG) with an α-tethering unit bearing pendent alkyne groups was "grafted-to" a gold electrode modified with 11-azide-undecathiol by a copper-catalyzed azide-alkyne cycloaddition reaction. Using the electrode, fetuin was potentiometrically detectable with a µM-order-sensitivity that is comparable to what is found in blood-collected specimen. Our finding may have implications for developing a remarkably economic hemodiagnostic technology with ease of downsizing and mass production.

Cell Scaffolds for Bone Tissue Engineering.

Currently, well-known surgical procedures for bone defects are classified into four types: (1) autogenous bone graft transplantation, (2) allogeneic bone graft transplantation, (3) xenogeneic bone graft transplantation, and (4) artificial bone graft transplantation. However, they are often risky procedures and related to postoperative complications. As an alternative, tissue engineering to regenerate new bone often involves the use of mesenchymal stem cells (MSCs), derived from bone marrow, adipose tissues, and so on, which are cultured into three-dimensional (3D) scaffolds to regenerate bone tissue by osteoinductive signaling. In this manuscript, we provide an overview of recent treatment of bone defects and the studies on the creation of cell scaffolds for bone regeneration. Bone regeneration from bone marrow-derived mesenchymal stem cells using silica nonwoven fabric by the authors' group were provided. Potential application and future direction of the present systems were also described.

Direct Observation of Cell Surface Sialylation by Atomic Force Microscopy Employing Boronic Acid-Sialic Acid Reversible Interaction.

Tracing cell surface sialylation dynamics at a scale of the glycolipoprotein microdomain (lipid rafts) formations remains an intriguing challenge of cellular biology. Here, we demonstrate that this goal is accessible, taking advantage of a boronic acid (BA)-based reversible molecular recognition chemistry. A BA-end-functionalized poly(ethylene glycol) was decorated onto an atomic force microscopy (AFM) cantilever, which provided a dynamic and sialic acid (SA)-specific imaging mode. Using this technique, we were able to heat map the SA expression levels not only on protein-decorated substrates but also directly on the cell surfaces, with a submicrometer scale resolution that may be relevant to that of the lipid rafts formation. The SA specificity and the binding reversibility of the probe were confirmed from its pH-dependent characteristics and an inhibition assay using free state SA. This finding may provide a noninvasive means for assessing a variety of SA-involved glycosylation dynamics spanning from physiology to pathology.

Improvement of Hepatic Functions by Spheroids Coculture with Fibroblasts in 3D Silica Nonwoven Fabrics.

In order to realize organ-on-a-chip as an effective tool for regenerative medicine and drug development, tissue-mimic cell culture methods which promote liver-specific function for long period have been developed. We have previously demonstrated that coculture of hepatocyte spheroids on fibroblasts using micropatterned substrate improved the hepatic functions due to the heterotypic cell-cell interactions and paracrine signaling from each other. In addition, hepatocyte function cultured as monolayer was also promoted in separately coculture with fibroblasts cultured as monolayer, and it is more improved in separately coculture with fibroblasts in 3D silica nonwoven fabrics. In this study, separately coculture of hepatocyte spheroids with fibroblasts cultured on 3D silica nonwoven fabrics was estimated for further improvement of hepatocyte functions. The hepatic function cocultured with fibroblast was more promoted than mono spheroids culture. The functional enhancement was significantly most improved in separately coculture with fibroblast in 3D silica nonwoven fabrics. Thus, these results were suggested that 3D culture of fibroblasts in 3D silica nonwoven fabrics increased the heterotypic secretion of paracrine factors, and it is essential for improved hepatic performance.

Increase in the apparent intercalation ability of a platinum complex via multivalency by installation into the sidechain of a graft copolymer and observation of structural changes in the intercalated DNA.

Metal complexes with planar structures have been utilized as DNA intercalators that can be inserted into the base pairs of DNA strands, and have potential applications in DNA-targeting drug therapies. When designing the intercalator metal complexes, controlling their interactions with DNA is important, and has been performed by modifying the chemical structure of the metal ligand. Herein, we designed a graft copolymer segment having Pt complexes with bipyridine and poly(ethylene glycol) (p(PEGMA-co-BPyMA-Pt)) as another strategy to control the interaction with DNA via a multivalent effect. The p(PEGMA-co-BPyMA-Pt) increased not only the binding constant as one macromolecule but also the apparent binding constant per intercalator unit compared to the Pt complex with bipyridine (BPy-Pt). Moreover, p(PEGMA-co-BPyMA-Pt) induced a larger change in DNA structure using lower amounts of Pt than BPy-Pt. These observed properties of p(PEGMA-co-BPyMA-Pt) suggest that grafting intercalators on polymer segments is a promising approach for designing novel types of intercalators.

N-Hydroxysuccinimide Bifunctionalized Triblock Cross-Linker Having Hydrolysis Property for a Biodegradable and Injectable Hydrogel System.

The design of biocompatible, degradable, and injectable hydrogel has been attractive for achievement of safe and efficient tissue engineering. Herein, we designed a N-hydroxysuccinimide (NHS) ester-terminated ABA triblock copolymer composed of poly(ethylene glycol) (PEG) as hydrophilic A segments and poly(dl-lactide) (PLA) as B segment having hydrolysis property (NHS-PEG-b-PLA-b-PEG-NHS) to be a cross-linker of polymer segments having amine groups for facile construction of injectable and degradable hydrogel. The PLA domain, which is widely accepted hydrolyzable segments, is inherently hydrophobic and simple introduction of the NHS group on the ends of PLA would not have high reactivity in aqueous milieu to construct injectable hydrogel. Thus, in this design, hydrophilic PEG was introduced as A segments to increase the reactivity of NHS groups at the ends of linkers by increasing the mobility. To demonstrate the property as a cross-linker for constructing degradable and injectable hydrogel, carboxylmethyl chitosan (CH), which is a polymer segment having amine groups, and NHS-PEG-b-PLA-b-PEG-NHS solutions were mixed to form the hydrogel (CH/PEG-PLA-PEG) under physiological condition. The formation of CH/PEG-PLA-PEG hydrogel proceeded within minute-order period after mixing the solutions, suggesting NHS-PEG-b-PLA-b-PEG-NHS is applicable to the cross-linker for construction of injectable hydrogel system with time-dependent gelation property. Degradation of the obtained CH/PEG-PLA-PEG hydrogel was observed, whereas that of CH/PEG, which was prepared from NHS-PEG-NHS and CH, was not observed, appealing the degradation property of the CH/PEG-PLA-PEG hydrogel based on hydrolysis of the PLA domain. Furthermore, chondrocytes embedded in CH/PEG-PLA-PEG hydrogels promoted collagen synthesis compared to CH/PEG. These demonstrations indicate the designed NHS-PEG-b-PLA-b-PEG-NHS is a promising cross-linker to construct the injectable and degradable hydrogel and eventually promote hydrogel performance as a tissue regeneration scaffold.

Preparation of Cell-Paved and -Incorporated Polysaccharide Hollow Fibers Using a Microfluidic Device.

Cellular constructs having hollow tubular structures are expected to be used as artificial blood vessels. We have recently demonstrated that water-insoluble polyion complexes (PICs) were formed from water-soluble polysaccharides with opposite charges at the interface of coaxial flows, which resulted in the formation of hollow fibers. In this study, both inside- and outside-cell-laden chondroitin sulfate C (CS)/chitosan (CHI) hollow fibers were prepared by utilizing a microfluidic device and modification with cell adhesive molecules. Loading of type I collagen (COL) and surface modification with fibronectin and gelatin using layer-by-layer assembly techniques improved the adhesion and spreading of fibroblast cells to/on the surface of CS/CHI hollow fibers. On the other hand, by suspending mesenchymal stem cells (MSCs) in the core flow solution, cells were successfully loaded in the walls of the hollow fibers. As the culture time extended, cells trapped in the PIC structures constituting the wall of the hollow fibers migrated to the interface between the hollow fibers and the medium: cells adhered to and stretched "on" the lumen surfaces in the COL-loaded fibers. In contrast, for the case of unmodified hollow fibers, it was difficult for cells to adhere to the lumen surfaces. Therefore, cell aggregates were formed "in" the lumen. Results of the live/dead assay and MTT assay clearly demonstrated that MSCs possessed certain levels of cell viability and proliferated for up to 10 days, especially for the cases of COL-loaded hollow fibers. On the basis of these results, the utility of the present hollow fibers in the formation of cellular constructs corresponding to blood vessels is also discussed.

Osteogenic Differentiation of Bone Marrow-Derived Mesenchymal Stem Cells in Electrospun Silica Nonwoven Fabrics.

Silica nonwoven fabrics (SNFs) with enough mechanical strength are candidates as implantable scaffolds. Culture of cells therein is expected to affect the proliferation and differentiation of the cells through cell-cell and cell-SNF interactions. In this study, we examined three-dimensional (3D) SNFs as a scaffold of mesenchymal stem cells (MSCs) for bone tissue engineering applications. The interconnected highly porous microstructure of 3D SNFs is expected to allow omnidirectional cell-cell interactions, and the morphological similarity of a silica nanofiber to that of a fibrous extracellular matrix can contribute to the promotion of cell functions. 3D SNFs were prepared by the sol-gel process, and their mechanical properties were characterized by the compression test and rheological analysis. In the compression test, SNFs showed a compressive elastic modulus of over 1 MPa and a compressive strength of about 200 kPa. These values are higher than those of porous polystyrene disks used for in vitro 3D cell culture. In rheological analysis, the elastic modulus and fracture stress were 3.27 ± 0.54 kPa and 25.9 ± 8.3 Pa, respectively. Then, human bone marrow-derived MSCs were cultured on SNFs, and the effects on proliferation and osteogenic differentiation were evaluated. The MSCs seeded on SNF proliferated, and the thickness of the cell layer became over 80 µm after 14 days of culture. The osteogenic differentiation of MSCs on SNFs was induced by the culture in the commercial osteogenic differentiation medium. The alkaline phosphatase activity of MSCs on SNFs increased rapidly and remained high up to 14 days and was much higher than that on two-dimensional tissue culture-treated polystyrene. The high expression of RUNX2 and intense staining by alizarin red s after differentiation supported that SNFs enhanced the osteogenic differentiation of MSCs. Furthermore, permeation analysis of SNFs using fluorescein isothiocyanate-dextran suggested a sufficient permeability of SNFs for oxygen, minerals, nutrients, and secretions, which is important for maintaining the cell viability and vitality. These results suggested that SNFs are promising scaffolds for the regeneration of bone defects using MSCs, originated from highly porous and elastic SNF characters.

Carbohydrate-based amphiphilic diblock copolymers with pyridine for the sensitive detection of protein binding.

Glycopolymers are useful macromolecules for presenting carbohydrates in multivalent form. Here, amphiphilic block copolymers consisting of hydrophilic lactose and hydrophobic pyridine were synthesized via reversible addition-fragmentation chain transfer polymerization (RAFT). RAFT polymerization of 2-O-methacryloyloxyethyl-(ß-D-lactoseheptaacetate) (2-O-MALac) was performed using cumyl dithiobenzoate (CDB) as the chain transfer agent to give well-defined glycopolymers. The livingness of the process was further demonstrated by successfully chain-extending one of obtained glycopolymers with 4-pyridyl methyl methacrylate affording narrow dispersed diblocks. With the obtained block copolymers, a glycosurface was generated on the gold surface of quartz crystal microbalance (QCM) through self-assembled strategy by the use of gold affinitive pyridine functional group. Furthermore, the resulting glycosurface was used to detect the binding of lactose specific lectin, ricinus communis agglutinin (RCA120) without non-specific protein adsorption.

Amphiphilic copolymer of poly(ethylene glycol)-block-polypyridine; synthesis, physicochemical characterization, and adsorption onto silica nanoparticle.

In this study, we newly synthesized amphiphilic block copolymers composed of hydrophilic poly(ethylene glycol) (PEG) and hydrophobic pyridine segments (PEG-b-Py). Chain transfer agent terminated PEG was subsequently chain-extended with 3-(4-pyridyl)-propyl acrylate to obtain PEG-b-Py by reversible additional-fragmentation chain transfer (RAFT) polymerization. Particularly, the effect of varying PEG molecular weight (M(n)) of the block copolymers (M(n) = 2000 (2k), and 5000 (5k)) was investigated in terms of critical micelle concentration (cmc), pyrene solubilization, micelle size distribution, and association number per micelle. Based on the amphiphilic balance, PEG-b-Pys formed core-shell type polymer micelle. The cmc value of PEG2k-b-Py was lower than that of PEG5k-b-Py, suggesting the degree of phase separation was strongly depended on PEG M(n). Furthermore, the adsorption of PEG-b-Py copolymer onto silica nanoparticles as dispersant was studied to estimate the effect of PEG M(n) in the copolymers and their solubility in the medium on the adsorption. Adsorbed density of PEG2k-b-Py copolymer onto silica nanoparticle was higher than that of PEG5k-b-Py, which was significantly correlated with the degree of phase-separation based on the amphiphilic balance. The adsorbed amount of copolymer was further changed as a function of solvent polarity, phase separation predicting the presence of the acid-base interaction between Py and silanol group existed on silica nanoparticles. The resultant dispersion stability was highly correlated with the graft density of copolymer onto silica surface. As a result, PEG2k-b-Py coated silica nanoparticles in aqueous media (with high solvent polarity) showed high dispersion stability. These fundamental investigations for the surface modification of the nanoparticle provide the insight into the highly stable colloidal dispersion as well as the design of dispersant molecular structure.

Multiarray formation of CHO spheroids cocultured with feeder cells for highly efficient protein production in serum-free medium.

Functional proteins like antibody, cytokine and growth factor have been widely used for basic biological research, diagnosis and cancer therapy. Particularly, antibody drugs as attractive biopharmaceuticals will be expected to create an enormous new market. Chinese hamster ovay (CHO) cells are being increasingly used in industry for the production of recombinant therapeutic proteins including antibody drugs. Although three-dimensional culture is preferred to two-dimensional monolayer culture for the efficient large scale culture of CHO cells and subsequent mass production of recombinant proteins, it has the limitation of low protein production. Therefore, a new cell culture em essentially required for an efficient protein production. Here we report on a new three-dimensional cell culture system as a spheroid cell culture on the micropattern array for efficient production of protein in CHO cells. Furthermore, cocultivation of CHO spheroids with feeder cells including bovine aortic endothelial cells (BAEC) and NIH 3T3 was essential to more increase a protein production. The results indicated that CHO heterospheroids cocultured with BAECs were much superior to either CHO monolayers or CHO homospheroids in protein production. Significantly, the above cocultured spheroids in the serum-free medium drastically enhanced protein expression level up to 3-fold compared with CHO spheroids in serum medium, suggesting that a coculture of spheroid system with feeder layer cells is a promising method to enhance protein production under serum-free condition. The spheroid array constructed here is highly usuful as a platform of biopharmaceutical manufacturing as well as tissue and cell based biosensors to detect a wide variety of clinically active compounds through a cellular physiological response.

Physicochemical characterization of the comb-type pyridine-co-poly(ethylene glycol) copolymer at the interface.

The novel amphiphilic comb-type copolymers were synthesized by copolymerization of a unit A that contains a pyridine (Py) portion and a unit B that contains a poly(ethylene glycol) (PEG) portion. The obtained copolymers consist of methoxy-endend PEG as a hydrophiphilic segment and Py as a hydrophobic and metal affinity segment (Py-co-PEG). Py-co-PEGs formed micelles and their physicochemical properties were intensively investigated in terms of critical micelle concentration, pyrene solubilization, and micelle size distribution. Furthermore, the gold nanoparticles (Au-NPs) were prepared using the Py-co-PEG polymeric micelles. Py-co-PEG has attained the long term interfacial stability by employing the multi-point adsorption of the Py unit on the gold surface, although usually prepared Au-NPs by thiol derivative are well-known to readily lose the dispersion stability under physiological and oxidative condition. It is important to note that Au-NPs protected by Py-co-PEG were drastically enhanced their dispersion stability under high ionic physiological and air oxidative conditions.