Jin Woo Lee

Interpenetrating polymer network (IPN) hydrogels composed of chitosan and poly(acrylic acid) (PAAc) were synthesized by UV irradiation method, and their structure, crystallinity, swelling behavior, thermal property, and mechanical property were investigated. Chitosan/PAAc IPNs exhibited relatively high equilibrium water content and also showed reasonable sensitivity to pH. From the swelling behaviors at various pH's, Fourier transform infrared spectra at high temperature and thermal analysis con

BACKGROUND: There has been no attempt to correlate the type and number of intra-articular lesions with the results of ligament reconstruction for chronic lateral ankle instability. HYPOTHESIS: Certain intra-articular lesions affect the clinical outcome of ligament reconstruction. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Sixty-five ankles from 64 patients underwent a modified Broström operation for chronic lateral ankle instability with a mean follow-up of 28.7 months (range, 12-

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BACKGROUND: The purpose of this study was to determine the sensitivity and specificity of MRI in chronic syndesmosis injury by comparing the arthroscopic findings with MRI findings and to suggest therapeutic guidelines of syndesmotic fixation. METHODS: Between January, 2003, and January, 2004, 20 patients were diagnosed with chronic syndesmosis injury according to syndesmosis widening (>2 mm) on arthroscopic examination. The average age of the patients was 32 years. The minimum followup was 22 (

The crucial trace element zinc stimulates osteogenesis in vitro and in vivo. However, the pathways mediating these effects remain poorly understood. This study aimed to investigate the effects of zinc on osteoblast differentiation in human bone marrow-derived mesenchymal stem cells (hBMSCs) and to identify the molecular mechanisms of these effects. In hBMSCs, zinc exposure resulted in a dose-dependent increase in osteogenesis and increased mRNA and protein levels of the master transcriptional fa

SOX2 is crucial for the maintenance of the self-renewal capacity and multipotency of mesenchymal stem cells (MSCs); however, the mechanism by which SOX2 is regulated remains unclear. Here, we report that RNA interference of sirtuin 1 (SIRT1) in human bone marrow (BM)-derived MSCs leads to a decrease of SOX2 protein, resulting in the deterioration of the self-renewal and differentiation capacities of BM-MSCs. Using immunoprecipitation, we demonstrated direct binding between SIRT1 and SOX2 in HeLa

Tissue engineering has the potential to provide cartilaginous constructs capable of restoring the normal function of native articular cartilage following joint injury or degradation. One approach to functional tissue engineering of cartilage involves the in vitro cultivation of tissue constructs by using: (i) chondrogenic cells that can be selected, expanded, and transfected to overexpress the genes of interest, (ii) scaffolds that provide a defined three-dimensional structure for tissue develop

BACKGROUND: Several studies have addressed the issue of the feasibility of arthroscopic surgery in older patients, usually by choosing an arbitrary age limit. HYPOTHESIS: Patient age is not associated with poor clinical outcome after arthroscopic surgery for osteochondral lesion of the talus (OLT), and other patient variables are the major determinants of clinical success/failure. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Between 2001 and 2008, 173 ankles underwent arthroscopic

NRF2 (nuclear factor erythroid-derived 2-like 2) plays an important role in defense against oxidative stress at the cellular level. Recently, the roles of NRF2 in embryonic and adult stem cells have been reported, but its role in maintaining self-renewal and differentiation potential remains unknown. We studied the mechanisms of NRF2 action in mesenchymal stem cells (MSCs) derived from human bone marrow. We found that the cellular localization of NRF2 changed during prolonged cell passage and os