Dong‐Hwee Kim

Focal adhesions are large protein complexes organized at the basal surface of cells, which physically connect the extracellular matrix to the cytoskeleton and have long been speculated to mediate cell migration. However, whether clustering of these molecular components into focal adhesions is actually required for these proteins to regulate cell motility is unclear. Here we use quantitative microscopy to characterize descriptors of focal adhesion and cell motility for mouse embryonic fibroblasts

Alterations in nuclear morphology are closely associated with essential cell functions, such as cell motility and polarization, and correlate with a wide range of human diseases, including cancer, muscular dystrophy, dilated cardiomyopathy, and progeria. However, the mechanics and forces that shape the nucleus are not well understood. Here, we demonstrate that when an adherent cell is detached from its substratum, the nucleus undergoes a large volumetric reduction accompanied by a morphological

Recent findings about cell fate change induced by physical stimuli have expedited the discovery of underlying regulatory mechanisms that determine stem cell differentiation. Progress with regards to micro-/nanofabrication technology have led to the development of advanced materials that can mimic biophysical features of in vivo related circumstances of the human body. Since the cellular microenvironment directly defines cellular structure and function, diverse material properties including stiff

Although eukaryotic cells are known to alternate between 'advancing' episodes of fast and persistent movement and 'hesitation' episodes of low speed and low persistence, the molecular mechanism that controls the dynamic changes in morphology, speed and persistence of eukaryotic migratory cells remains unclear. Here, we show that the movement of the interphase nucleus during random cell migration switches intermittently between two distinct modes - rotation and translocation - that follow with hi

The perinuclear actin cap (or actin cap) is a recently characterized cytoskeletal organelle composed of thick, parallel, and highly contractile acto-myosin filaments that are specifically anchored to the apical surface of the interphase nucleus. The actin cap is present in a wide range of adherent eukaryotic cells, but is disrupted in several human diseases, including laminopathies and cancer. Through its large terminating focal adhesions and anchorage to the nuclear lamina and nuclear envelope

Efficient cell migration is central to the normal development of tissues and organs and is involved in a wide range of human diseases, including cancer metastasis, immune responses, and cardiovascular disorders. Mesenchymal migration is modulated by focal-adhesion proteins, which organize into large integrin-rich protein complexes at the basal surface of adherent cells. Whether the extent of clustering of focal-adhesion proteins is actually required for effective migration is unclear. We recentl

Asterias pectinifera, a starfish that has been known to ruin the aquaculture industry owing to its voracious appetite, has recently been identified as an eco-friendly source of non-toxic and highly water-soluble low-molecular weight collagen peptides, which promotes wound healing, bone regeneration, and skin protection. Although they have potential applications in biomedical applications, including pharmaceuticals and cosmetic products, it remains unclear how to improve the in vivo absorption of

Cells respond and actively adapt to environmental cues in the form of mechanical stimuli. This extends to immune cells and their critical role in the maintenance of tissue homeostasis. Multiple recent studies have begun illuminating underlying mechanisms of mechanosensation in modulating immune cell phenotypes. Since the extracellular microenvironment is critical to modify cellular physiology that ultimately determines the functionality of the cell, understanding the interactions between immune

The cellular microenvironment plays an important role in regulating cancer progress. Cancer can physically and chemically remodel its surrounding extracellular matrix (ECM). Critical cellular behaviors such as recognition of matrix geometry and rigidity, cell polarization and motility, cytoskeletal reorganization, and proliferation can be changed as a consequence of these ECM alternations. Here, we present an overview of cancer mechanobiology in detail, focusing on cancer microenvironmental sens

Extracellular mechanical stimuli are translated into biochemical signals inside the cell via mechanotransduction. The nucleus plays a critical role in mechanoregulation, which encompasses mechanosensing and mechanotransduction. The nuclear lamina underlying the inner nuclear membrane not only maintains the structural integrity, but also connects the cytoskeleton to the nuclear envelope. Lamin mutations, therefore, dysregulate the nuclear response, resulting in abnormal mechanoregulations, and ul

The engineered three-dimensional (3D) cell cultivation system for the production of multicellular spheroids has attracted considerable attention due to its improved in vivo relevance to cellular communications compared with the traditional two-dimensional (2D) cell culture platform. The formation and maintenance of cell spheroids in a healthy condition is the critical factor for tissue engineering applications such as the repair of damaged tissues, the development of organ replacement parts and

In native microenvironment, diverse physical barriers exist to dynamically modulate stem cell recruitment and differentiation for tissue repair. In this study, nanoassembly-based magnetic screens of various sizes are utilized, and they are elastically tethered over an RGD ligand (cell-adhesive motif)-presenting material surface to generate various nanogaps between the screens and the RGDs without modulating the RGD density. Large screens exhibiting low RGD distribution stimulate integrin cluster

The multifaceted biological defense system modulating complex immune responses against pathogens and foreign materials plays a critical role in tissue homeostasis and disease progression. Recently developed biomaterials that can specifically regulate immune responses, nanoparticles, graphene, and functional hydrogels have contributed to the advancement of tissue engineering as well as disease treatment. The interaction between innate and adaptive immunity, collectively determining immune respons