Yoonsung Nam

Poly(L-lactic acid) and its copolymers with D-lactic and glycolic acid were used to fabricate various porous biodegradable scaffolds suitable for tissue engineering and drug delivery based on a thermally induced phase separation (TIPS) technique. A variety of parameters involved in TIPS process, such as types of polymers, polymer concentration, solvent/nonsolvent ratio, and quenching temperature, were examined in detail to produce a wide array of micro- and macroporous structures. A mixture of d

Highly open porous biodegradable poly(L-lactic acid) ¿PLLA scaffolds for tissue regeneration were fabricated by using ammonium bicarbonate as an efficient gas foaming agent as well as a particulate porogen salt. A binary mixture of PLLA-solvent gel containing dispersed ammonium bicarbonate salt particles, which became a paste state, was cast in a mold and subsequently immersed in a hot water solution to permit the evolution of ammonia and carbon dioxide within the solidifying polymer matrix. Thi

Biotemplated synthesis of functional nanomaterials has received increasing attention for applications in energy, catalysis, bioimaging, and other technologies. This approach is justified by the unique abilities of biological systems to guide sophisticated assembly and organization of molecules and materials into distinctive nanoscale morphologies that exhibit physicochemical properties highly desirable for specific purposes. Here, we present a high-performance, flexible nanogenerator using aniso

Biological molecules can be used as versatile templates for assembling nanoscale materials because of their unique structures and chemical diversities. Supramolecular organization of molecular pigments, as is found in the natural light-harvesting antenna, has drawn attention for its potential applications to sensors, photocatalytic systems, and photonic devices. Here we show the arrangement of molecular pigments into a one-dimensional light-harvesting antenna using M13 viruses as scaffolds. Chem

Given path: A polydopamine-based, pump-free, two-dimensional microfluidic system is energy-efficiently operated by gravity (see picture). The device consists of polydopamine (pD) micro-patterns on nanostructured, superhydrophobic anodized aluminum oxide (AAO) surfaces on which liquid droplets move along the micro-patterned paths of the polydopamine. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited

Here, we report quantum dot-incorporating solid lipid nanoparticles (SLNs) for anticancer theranostics with synergistic therapeutic effects of paclitaxel-siRNA combination. The natural components of a low-density lipoprotein (LDL) are reconstituted to produce LDL-mimetic SLNs having a stable core/shell nanostructure incorporating quantum dots and paclitaxel within the lipid shell while anionic siRNA molecules are electrostatically complexed with the outer surface of SLNs. The produced SLN/siRNA

Abstract Catechol, a unique adhesive molecule found in mussel proteins, can reduce metal ions while it is oxidized and polymerized with amines to polydopamine (pD). Here, pD coatings are employed with simultaneous reduction of metal ions to prepare electrospun polymer nanofibers functionalized with metal nanoparticles. The oxidative polymerization of dopamines mediates the reduction of silver ions to metallic silver nanoparticles and their deposition on polymer nanofibers. The formation of silve

Small interfering RNA (siRNA) has proved to be a powerful tool for target-specific gene silencing via RNA interference (RNAi). Its ability to control targeted gene expression gives new hope to gene therapy as a treatment for cancers and genetic diseases. However, siRNA shows poor pharmacological properties, such as low serum stability, off-targeting, and innate immune responses, which present a significant challenge for clinical applications. In addition, siRNA cannot cross the cell membrane for

Rat hepatocytes were cultured onto the surface of various amorphous biodegradable polymers composed of lactic acid and glycolic acid which were partially surface hydrolyzed by treating with sodium hydroxide. The polymer surface progressively became more hydrophilic with increasing NaOH treatment time, which was confirmed by measuring water contact angles and XPS results. The number of hepatocytes attached onto the NaOH treated hydrophilic surfaces was greater than that of the non-treated control

Novel metal nanostructures immobilized within three-dimensional (3D) porous polymeric scaffolds have been utilized for catalysts and biosensors. However, efficient, robust immobilization of the nanostructures both outside and inside of the 3D scaffolds is a challenging task. To address the challenge, we synthesized a redox-active polymer, catechol-grafted poly(vinyl alcohol), PVA-g-ct. The grafted catechol is inspired by the adhesion mechanism of marine mussels, which facilitates binding and red

Programmable molecular self-assembly of siRNA molecules provides precisely controlled generation of dendrimeric siRNA nanostructures. The second-generation dendrimers of siRNA can be effectively complexed with a low-molecular-weight, cationic polymer (poly(β-amino ester), PBAE) to generate stable nanostructures about 160 nm in diameter via strong electrostatic interactions. Condensation and gene silencing efficiencies increase with the increased generation of siRNA dendrimers due to a high charg