Publications by authors named "Jihun Song"

5 Publications

  • Page 1 of 1

Poly(amino ester)-Based Polymers for Gene and Drug Delivery Systems and Further Application toward Cell Culture System.

Macromol Biosci 2021 Aug 12;21(8):e2100106. Epub 2021 Jun 12.

School of Chemical Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea.

Various synthetic polymers based on poly(amino ester) (PAE) are suggested as candidates for gene and drug delivery owing to their pH-responsiveness, which contributes to efficient delivery performance. PAE-based pH-responsive polymers are more biodegradable and hydrophilic than other types of pH-responsive polymers. The functionality of PAE-based polymers can be reinforced by using different chemical modifications to improve the efficiency of gene and drug delivery. Additionally, PAE-based polymers are used in many ways in the biomedical field, such as in transdermal delivery and stem cell culture systems. Here, the recent novel PAE-based polymers designed for gene and drug delivery systems along with their further applications toward adult stem cell culture systems are reviewed. The synthetic tactics are contemplated and pros and cons of each type of polymer are analyzed, and detailed examples of the different types are analyzed.
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http://dx.doi.org/10.1002/mabi.202100106DOI Listing
August 2021

Shift Work and Dry Eye Disease in the Korean Working Population: A Population-Based Cross-Sectional Study.

Int J Environ Res Public Health 2021 05 20;18(10). Epub 2021 May 20.

Department of Occupational and Environmental Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea.

This study aimed to evaluate the association between shift work and dry eye disease (DED) in the general population. The 2011 Korea Health Panel (KHP) was used. Chi-square test and multivariate logistic regression were used to assess the relationship between shift work and DED. Stratification analysis was conducted by sex and age. Overall, the odds ratio (OR) of DED according to shift work did not showed significant results (adjusted OR = 1.230, 95% CI 0.758-1.901). When findings were stratified based on age older or younger than 40 years, the OR of DED increased to 2.85 (95% CI: 1.25-5.90) in shift workers under 40 years of age. Our results show an association between shift work and DED in a group of younger subjects.
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http://dx.doi.org/10.3390/ijerph18105492DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8161339PMC
May 2021

Development of pH-Responsive Polymer Coating as an Alternative to Enzyme-Based Stem Cell Dissociation for Cell Therapy.

Materials (Basel) 2021 Jan 20;14(3). Epub 2021 Jan 20.

School of Chemical Engineering, Sungkyunkwan University, Suwon 16419, Korea.

Cell therapy usually accompanies cell detachment as an essential process in cell culture and cell collection for transplantation. However, conventional methods based on enzymatic cell detachment can cause cellular damage including cell death and senescence during the routine cell detaching step due to an inappropriate handing. The aim of the current study is to apply the pH-responsive degradation property of poly (amino ester) to the surface of a cell culture dish to provide a simple and easy alternative method for cell detachment that can substitute the conventional enzyme treatment. In this study, poly (amino ester) was modified (cell detachable polymer, CDP) to show appropriate pH-responsive degradation under mild acidic conditions (0.05% (w/v) CDP, pH 6.0) to detach stem cells (human adipose tissue-derived stem cells (hADSCs)) perfectly within a short period (less than 10 min). Compared to conventional enzymatic cell detachment, hADSCs cultured on and detached from a CDP-coated cell culture dish showed similar cellular properties. We further performed in vivo experiments on a mouse hindlimb ischemia model (1.0 × 10 cells per limb). The in vivo results indicated that hADSCs retrieved from normal cell culture dishes and CDP-coated cell culture dishes showed analogous therapeutic angiogenesis. In conclusion, CDP could be applied to a pH-responsive cell detachment system as a simple and easy nonenzymatic method for stem cell culture and various cell therapies.
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http://dx.doi.org/10.3390/ma14030491DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7864336PMC
January 2021

Dual Ion Releasing Nanoparticles for Modulating Osteogenic Cellular Microenvironment of Human Mesenchymal Stem Cells.

Materials (Basel) 2021 Jan 15;14(2). Epub 2021 Jan 15.

School of Chemical Engineering, Sungkyunkwan University, Suwon 16419, Korea.

In this study we developed a dual therapeutic metal ion-releasing nanoparticle for advanced osteogenic differentiation of stem cells. In order to enhance the osteogenic differentiation of human mesenchymal stem cells (hMSCs) and induce angiogenesis, zinc (Zn) and iron (Fe) were synthesized together into a nanoparticle with a pH-sensitive degradation property. Zn and Fe were loaded within the nanoparticles to promote early osteogenic gene expression and to induce angiogenic paracrine factor secretion for hMSCs. In vitro studies revealed that treating an optimized concentration of our zinc-based iron oxide nanoparticles to hMSCs delivered Zn and Fe ion in a controlled release manner and supported osteogenic gene expression (RUNX2 and alkaline phosphatase) with improved vascular endothelial growth factor secretion. Simultaneous intracellular release of Zn and Fe ions through the endocytosis of the nanoparticles further modulated the mild reactive oxygen species generation level in hMSCs without cytotoxicity and thus improved the osteogenic capacity of the stem cells. Current results suggest that our dual ion releasing nanoparticles might provide a promising platform for future biomedical applications.
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http://dx.doi.org/10.3390/ma14020412DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7830414PMC
January 2021

The effect of knee flexion angles and ground conditions on the muscle activation of the lower extremity in the squat position.

J Phys Ther Sci 2017 Oct 21;29(10):1852-1855. Epub 2017 Oct 21.

Department of Physical Therapy, College of Health and Welfare, Silla University: 700 beon-gil, 140 Baegyang-daero, Sasang-gu, Busan 46958, Republic of Korea.

[Purpose] The purpose of this study is to research the most effective knee flexion angle and ground condition in the squat position. [Subjects and Methods] The subjects of this study were 15 female college students who were able to perform squat movements and who had never previously experienced surgery, orthopedic disease, or musculoskeletal impairment. This study was conducted to examine changes of muscle activation of low-extremity muscles at different knee flexion angles of 70°, 90°, and 100°. Balance Pad (Aero Step, TOGU, Germany) was used as unstable ground. Surface electromyogram (4D-MT & EMD-11, Relive, Korea) was used for measuring muscle activation. Measured muscles were vastus medialis, biceps femoris, tibialis anterior, and gastrocnemius. Muscle activation was determined by the root mean square (RMS). [Results] There was a difference in muscle activation of the vastus medialis and tibialis anterior according to the change of the knee flexion angle with the stable ground. However, there was no difference in muscle activation of the lower extremity muscles according to the change of the knee flexion angle with the unstable ground. [Conclusion] These results suggest that changes in the angle of the knee flexion with the stable ground affect the muscle activation of the vastus medialis and tibialis anterior. It was found that as the joint angle increases, muscle activation also increases. However, ground condition does not affect muscle activation.
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http://dx.doi.org/10.1589/jpts.29.1852DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5684026PMC
October 2017
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