Hojeong Jeon

Electrospinning has been used for the fabrication of extracellular matrix (ECM)-mimicking fibrous scaffolds for several decades. Electrospun fibrous scaffolds provide nanoscale/microscale fibrous structures with interconnecting pores, resembling natural ECM in tissues, and showing a high potential to facilitate the formation of artificial functional tissues. In this review, we summarize the fundamental principles of electrospinning processes for generating complex fibrous scaffold geometries tha

A monolayer of endothelial cells (ECs) aligned along the direction of blood flow plays crucial roles in the regulation of anti-thrombogenic and pro-inflammatory reactions in the blood vessel wall. Thus, many researchers have attempted to mimic the aligned structure of ECs in vascular grafts or tissue-engineered blood vessels. In the present study, we fabricated micro-groove patterned nanofibers using a femtosecond laser ablation technique to recapitulate the densely organized anisotropic archite

We applied 2-photon laser ablation to write subdiffraction nanoscale chemical patterns into ultrathin polymer films under ambient conditions. Poly(ethylene glycol) methacrylate brush layers were prepared on quartz substrates via surface-initiated atom-transfer radical polymerization and ablated to expose the underlying substrate using the nonlinear 2-photon absorbance of a frequency-doubled Ti:sapphire femtosecond laser. Single-shot ablation thresholds of polymer films were ~1.5 times smaller th

Abstract Owing to enhanced biocompatibility and osseointegration, hydroxyapatite (HAp) coatings are often applied to biomedical devices that are implanted directly on the bone. Although various HAp coating techniques have been developed, they are restricted due to the time‐consuming HAp synthesis and additional coating processes. Herein, the development of a rapid single‐step method for simultaneous synthesis and coating of HAp via nanosecond laser surface treatment is described. In the conventi

A microfluidic device to quantify bacterial chemotaxis has been proposed, which generates a linear concentration gradient of chemoattractant in the main channel only by convective and molecular diffusion, and which enables the bacteria to enter the main channel in a single file by hydrodynamic focusing technique. The trajectory of each bacterium in response to the concentration gradient of chemoattractant is photographed by a CCD camera and its velocity is acquired by a simple PTV (Particle Trac

Topographically patterned surfaces are known to be powerful tools for influencing cellular functions. Here we demonstrate a method for fabricating high aspect ratio ( approximately 10) patterns of varying height by using two-photon polymerization process to study contact guidance of cells. Ridge patterns of various heights and widths were fabricated through single laser scanning steps by low numerical aperture optics, hence at much higher processing throughput. Fibroblast cells were seeded on pa

Prompt and robust bone regeneration has been clinically achieved using supraphysiological doses of bone morphogenetic protein-2 (BMP-2) to overcome the short half-life and rapid clearance. However, uncontrolled burst release of exogenous BMP-2 causes severe complications such as heterotopic ossification and soft tissue inflammation. Therefore, numerous researches have focused on developing a new BMP-2 delivery system for a sustained release profile by immobilizing BMP-2 in various polymeric vehi

Synthetic biomaterials are used to overcome the limited quantity of human-derived biomaterials and to impart additional biofunctionality. Although numerous synthetic processes have been developed using various phases and methods, currently commonly used processes have some issues, such as a long process time and difficulties with extensive size control and high-concentration metal ion substitution to achieve additional functionality. Herein, we introduce a rapid synthesis method using a laser-in

Photolithography is a well-established fabrication method for realizing multilayer electronic circuits. However, it is challenging to adopt photolithography to fabricate intrinsically stretchable multilayer electronic circuits fully composed of an elastomeric matrix, due to the opacity of thick stretchable nanocomposite conductors. Here, we present photothermal lithography that can pattern elastomeric conductors and via holes using pulsed lasers. The photothermal-patterned stretchable nanocompos

Lasers that exhibit monochromaticity, directionality, coherence, and focusability have been used in health care and defense industries for over five decades. Recently, the application of lasers in medical and biomedical devices has increased significantly. Considering biomedical devices and materials are attached to the skin or implanted into the body, the immune response, inflammation control, cell adhesion, migration, and biocompatibility of the device must be investigated. Therefore, research

Contractility of cells in wound site is important to understand pathological wound healing and develop therapeutic strategies. In particular, contractile force generated by cells is a basic element for designing artificial three-dimensional cell culture scaffolds. Direct assessment of deformation of three-dimensional structured materials has been used to calculate contractile forces by averaging total forces with respect to the cell population number. However, macroscopic methods have offered on