Repository Community: null
http://hdl.handle.net/20.500.11750/4341
2024-03-28T08:35:22Z
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Precision Engineering of Polydopamine: Advances in Spatial Fabrication Techniques
http://hdl.handle.net/20.500.11750/56538
Title: Precision Engineering of Polydopamine: Advances in Spatial Fabrication Techniques
Author(s): Jeong, Haejin; Hong, Seonki
Abstract: Currently available patterning methods, such as lithographic techniques and inkjet printing approaches, heavily rely on material properties and specific applications. This motivates us to explore and develop patterning strategies tailored to the unique characteristics of materials. In this context, we discuss the advancements in site-specific fabrication and patterning of polydopamine (pDA), a versatile coating material widely utilized in biomedical devices. First, we provide a brief Review of the current understanding of the chemical structure of pDA, addressing the ongoing challenges related to its uncontrollability due to its heterogeneous nature. Following this, we examine the control of the shape and morphology during the growth of pDA in the solution phase. Lastly, we comprehensively cover various patterning strategies specifically developed and optimized for the pDA coating. Our goal is to offer insights into the controllable synthesis and fabrication of pDA. We anticipate that this Review will contribute to the advancement of precise and tailored pDA coatings, opening up possibilities for applications in diverse fields, particularly in integrated devices and molecular architecting. © 2024 American Chemical Society.
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In vitro and in vivo analysis of visible light crosslinkable gelatin methacryloyl (GelMA) hydrogels
http://hdl.handle.net/20.500.11750/56368
Title: In vitro and in vivo analysis of visible light crosslinkable gelatin methacryloyl (GelMA) hydrogels
Author(s): Noshadi, Iman; Hong, Seonki; Sullivan, Kelly E.; Shirzaei Sani, Ehsan; Portillo-Lara, Roberto; Tamayol, Ali; Shin, Su Ryon; Gao, Albert E.; Stoppel, Whitney L.; Black, Lauren D. III; Khademhosseini, Ali; Annabi, Nasim
Abstract: Photocrosslinkable materials have been frequently used for constructing soft and biomimetic hydrogels for tissue engineering. Although ultraviolet (UV) light is commonly used for photocrosslinking such materials, its use has been associated with several biosafety concerns such as DNA damage, accelerated aging of tissues, and cancer. Here we report an injectable visible light crosslinked gelatin-based hydrogel for myocardium regeneration. Mechanical characterization revealed that the compressive moduli of the engineered hydrogels could be tuned in the range of 5-56 kPa by changing the concentrations of the initiator, co-initiator and co-monomer in the precursor formulation. In addition, the average pore sizes (26-103 μm) and swelling ratios (7-13%) were also shown to be tunable by varying the hydrogel formulation. In vitro studies showed that visible light crosslinked GelMA hydrogels supported the growth and function of primary cardiomyocytes (CMs). In addition, the engineered materials were shown to be biocompatible in vivo, and could be successfully delivered to the heart after myocardial infarction in an animal model to promote tissue healing. The developed visible light crosslinked hydrogel could be used for the repair of various soft tissues such as the myocardium and for the treatment of cardiovascular diseases with enhanced therapeutic functionality. ©2017 The Royal Society of Chemistry.
2017-09-30T15:00:00Z
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Biocompatible polydopamine based triboelectric nanogenerator for humidity sensing
http://hdl.handle.net/20.500.11750/47743
Title: Biocompatible polydopamine based triboelectric nanogenerator for humidity sensing
Author(s): Panda, Swati; Jeong, Haejin; Hajra, Sugato; Rajaitha, Peter Mary; Hong, Seonki; Kim, Hoe Joon
Abstract: Humidity sensing is a critical parameter for various applications, ranging from environmental monitoring to healthcare and food packaging. Traditional humidity sensors show respectable sensitivity but suffer from a shorter battery life span and slow response time. However, the triboelectric nanogenerator (TENG) technology has emerged as a promising alternative for humidity sensing, offering superior performance and compatibility with various substrates. TENGs can convert mechanical energy into electrical energy without needing an external power source. This unique feature makes TENG a promising platform for self-powered environmental sensors. In this context, synthesizing biocompatible polydopamine (PDA) material and using it for a humidity sensing layer represents a significant step toward advancing next-generation sensors. This study presents a biocompatible PDA-incorporated 3D-printed TENG for self-powered humidity sensing. The output voltage and current of the multi-unit TENG is measured to be 90 V and 2.4 μA, respectively. The TENG demonstrates a sensitivity of 1.55 V/10 RH% over the relative humidity range from 25 % to 92 %. As humidity increases, the resistance of the humidity sensor decreases, resulting in a reduction in electrical voltage output. TENG has potential applications in various fields and could be a promising candidate for next-generation humidity sensors. © 2023 Elsevier B.V.
2023-10-31T15:00:00Z
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Carbohydrate-protein interaction-based detection of pathogenic bacteria using a biodegradable self-powered biosensor
http://hdl.handle.net/20.500.11750/47742
Title: Carbohydrate-protein interaction-based detection of pathogenic bacteria using a biodegradable self-powered biosensor
Author(s): Panda, Swati; Hajra, Sugato; Kim, Hang-Gyeom; Jeong, Haejin; Achary, P. G. R.; Hong, Seonki; Dudem, Bhaskar; Silva, S. Ravi P.; Vivekananthan, Venkateswaran; Kim, Hoe Joon
Abstract: Battery-free and biodegradable sensors can detect biological elements in remote areas. The triboelectric nanogenerator (TENG) can potentially eliminate the need for a battery by simply converting the abundant vibrations from nature or human motion into electricity. A biodegradable sensor system integrated with TENG to detect commonly found disease-causing bacteria (E. coli) in the environment is showcased herein. In this system, d-mannose functionalized 3D printed polylactic acid (PLA) with the brush-painted silver electrode was used to detect E. coli by a simple carbohydrate-protein interaction mechanism. The adsorption capacity of d-mannose is generally altered by varying the concentration of E. coli resulting in changes in resistance. Thus, the presented biosensor can detect bacterial concentrations by monitoring the output current. The PLA TENG generates an output of 70 V, 800 nA, and 22 nC, respectively. In addition, tap water and unpasteurized milk samples are tested for detecting bacteria, and the output is measured at 6 μA and 5 μA, respectively. Further, the biosensor was tested for biodegradability in soil compost by maintaining constant temperature and humidity. This study not only proposes an efficient and fast method for screening E. coli but also gives important insights into the ability to degrade and long-term reliability of TENG-based sensor platforms. © 2023 The Royal Society of Chemistry
2023-10-31T15:00:00Z