Chaenyung Cha

Functional carbon-based nanomaterials (CBNs) have become important due to their unique combinations of chemical and physical properties (i.e., thermal and electrical conductivity, high mechanical strength, and optical properties), and extensive research efforts are being made to utilize these materials for various industrial applications, such as high-strength materials and electronics. These advantageous properties of CBNs are also actively investigated in several areas of biomedical engineerin

Graphene-based materials are useful reinforcing agents to modify the mechanical properties of hydrogels. Here, an approach is presented to covalently incorporate graphene oxide (GO) into hydrogels via radical copolymerization to enhance the dispersion and conjugation of GO sheets within the hydrogels. GO is chemically modified to present surface-grafted methacrylate groups (MeGO). In comparison to GO, higher concentrations of MeGO can be stably dispersed in a pre-gel solution containing methacry

As stem cells are a cornerstone of regenerative medicine, research efforts have been extensively focused on controlling their self-renewal and differentiation. It is well-known that stem cells are tightly regulated by a combination of physical and chemical factors from their complex extracellular surroundings; thus, conventional cell culture approaches based purely on using soluble factors to direct stem cell fate have resulted in limited success. To account for the complexities of native stem-c

Hydrogels commonly used in tissue engineering are mechanically soft, thus often display structural weakness. Herein, we introduce a strategy for enhancing the structural integrity and fracture toughness of cell-laden hydrogels by incorporating a three-dimensional (3D) microfabricated scaffold as a structural element. A digital micromirror device projection printing (DMD-PP) system, a rapid prototyping technology which employs a layer-by-layer stereolithographic approach, was utilized to efficien

Abstract Hydrogels are being increasingly studied for use in various biomedical applications including drug delivery and tissue engineering. The successful use of a hydrogel in these applications greatly relies on a refined control of the mechanical properties including stiffness, toughness, and the degradation rate. However, it is still challenging to control the hydrogel properties in an independent manner due to the interdependency between hydrogel properties. Here it is hypothesized that a b

Hydrogel meets silicone: The chemical functionalization of a polydimethylsiloxane (PDMS) surface with polysaccharide “glue” induces a strong, permanent adhesion between the hydrogel and PDMS. This hydrogel-coated silicone substrate was useful for controlling cellular organization under mechanical stretching (see picture) and also in fabricating microfluidic devices filled with the gel.

Thermoresponsive poly(N-isopropylacrylamide) (PNIPAm)-based hydrogels are widely investigated for their ability to alter their physical properties (e.g. dimensions, swelling/deswelling) in response to change in temperature. Despite extensive research efforts, it is still challenging to control various aspects of thermoresponsive physical properties of PNIPAm hydrogels in an efficient and comprehensive manner using conventional small molecular crosslinkers due to their limited solubility and func

Tumor spheroids are considered a valuable three dimensional (3D) tissue model to study various aspects of tumor physiology for biomedical applications such as tissue engineering and drug screening as well as basic scientific endeavors, as several cell types can efficiently form spheroids by themselves in both suspension and adherent cell cultures. However, it is more desirable to utilize a 3D scaffold with tunable properties to create more physiologically relevant tumor spheroids as well as opti

Abstract Microfabrication technology has emerged as a valuable tool for fabricating structures with high resolution and complex architecture for tissue engineering applications. For this purpose, it is imperative to develop “bioink” that can be readily converted to a solid structure by the modus operandi of a chosen apparatus, while optimally supporting the biological functions by tuning their physicochemical properties. Herein, a photocrosslinkable hyperbranched polyglycerol (acrylic hyperbranc

Hydrogels possess favorable physical properties ideally suited for various biotechnology applications. To tailor to specific needs, a number of modification strategies have been employed to tune their properties. Herein, a multifunctional polymeric cross-linker based on polyaspartamide is developed, which allows for the facile adjustment of the type and number of reactive functional groups to fit different reaction schemes and control the physical properties of the hydrogels. The amine-based nuc