• Title/Summary/Keyword: K-based hydrogel

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Novel Superabsorbent Hydrogel Based on Natural Hybrid Backbone: Optimized Synthesis and its Swelling Behavior

  • Pourjavadi, Ali;Soleyman, Rouhollah;Bardajee, Ghasem Rezanejade;Ghavami, Somayeh
    • Bulletin of the Korean Chemical Society
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    • v.30 no.11
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    • pp.2680-2686
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    • 2009
  • The synthesis of a novel superabsorbent hydrogel with natural hybrid backbone via graft copolymerization of acrylamide (AAm) onto kappa-carrageenan (kC, as a polysaccharide) and gelatin (as a protein) under classic thermal conditions is described. The Taguchi method as a strong experimental design tool was used for synthesis optimization. A series of hydrogels were synthesized by proposed conditions of Qualitek-4 Software. Considering the results of 9 trials according to analysis of variance (ANOVA), optimum conditions were proposed. The swelling behavior of optimum hydrogel was measured in various solutions with pH values ranging from 1 to 13. In addition, swelling kinetics, swelling in various organic solvents, various salt solutions and On–Off switching behavior were investigated. The hydrogel formation was confirmed by Fourier transform infrared spectroscopy (FTIR) and thermogravimetrical analysis (TGA). Surface morphology of the synthesized hydrogels was assessed by scanning electron microscope (SEM).

Micro pH Sensor Using Patterned Hydrogel with pH Indicators

  • Jang, Ji-Sung;Kwon, Sung-Hoon
    • Journal of Sensor Science and Technology
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    • v.20 no.4
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    • pp.234-237
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    • 2011
  • This paper presents a study into pH Indicator-Embedded hydrogel micro-particles which are encoded various shapes according to the captured indicator. We incorporate various pH indicators into a photo-curable hydrogel, PEG-DA(Poly(ethylene glycol) diacrylate). Using the latest fluidic lithography techniques, we can easily fabricate variously patterned hydrogel particles based on in-situ photopolymerization of the PEG-DA in a micro-fluidic channel. The shape of the particle is related to the pH indicator inside the particle. We demonstrate that the micro pH sensors change their colors according to the pH levels. The micro pH sensors have various characteristics that are related to the curing time, particle size, etc. By changing these conditions, we can adjust the long term stability and reaction time of the hybrid micro pH sensors.

Development of a Three-dimensional Hydrogel System for the Maintenance of Porcine Spermatogonial Stem Cell Self-renewal

  • Park, Ji Eun;Park, Min Hee;Kim, Min Seong;Yun, Jung Im;Choi, Jung Hoon;Lee, Eunsong;Lee, Seung Tae
    • Journal of Embryo Transfer
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    • v.32 no.4
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    • pp.343-351
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    • 2017
  • Porcine spermatogonial stem cells (SSCs) prefer three-dimensional (3D) culture systems to 2D ones for the maintenance of self-renewal. Of the many 3D culture systems, agar-based hydrogels are candidates for supporting porcine SSC self-renewal, and there are various types of agar powder that can be used. In this study, we sought to identify an agar-based 3D hydrogel system that exhibited strong efficacy in the maintenance of porcine SSC self-renewal. First, 3D hydrogels with different mechanics were prepared with various concentrations of Bacto agar, lysogeny broth (LB) agar, and agarose powder, and the 3D hydrogel with the strongest alkaline phosphatase (AP) activity and greatest increase in colony size was identified for the different types of agar powder. Second, among the porcine SSCs cultured in the different 3D hydrogels, we analyzed the colony formation, morphology, and size; AP activity; and transcription and translation of porcine SSC-related genes, and these were compared to determine the optimal 3D hydrogel system for the maintenance of porcine SSC self-renewal. We found that 0.6% (w/v) Bacto agar-, 1% (w/v) LB agar-, and 0.2% (w/v) agarose-based 3D hydrogels showed the strongest maintenance of AP activity and the most pronounced increase in colony size in the culture of porcine SSCs. Moreover, among these hydrogels, the strongest transcription and translation of porcine SSC-related genes and largest colony size were detected in porcine SSCs cultured in the 0.2% (w/v) agarose-based 3D hydrogel, whereas there were no significant differences in colony formation and morphology. These results demonstrate that the 0.2% (w/v) agarose-based 3D hydrogel can be effectively used for the maintenance of porcine SSC self-renewal.

Effect of bFGF and fibroblasts combined with hyaluronic acid-based hydrogels on soft tissue augmentation: an experimental study in rats

  • Lee, Su Yeon;Park, Yongdoo;Hwang, Soon Jung
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.41
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    • pp.47.1-47.10
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    • 2019
  • Background: Hyaluronic acid (HA) has been applied as a primary biomaterial for temporary soft tissue augmentation and as a carrier for cells and the delivery of growth factors to promote tissue regeneration. Although HA derivatives are the most versatile soft tissue fillers on the market, they are resorbed early, within 3 to 12 months. To overcome their short duration, they can be combined with cells or growth factors. The purpose of this study was to investigate the stimulating effects of human fibroblasts and basic fibroblast growth factors (bFGF) on collagen synthesis during soft tissue augmentation by HA hydrogels and to compare these with the effects of a commercial HA derivative (Restylane®). Methods: The hydrogel group included four conditions. The first condition consisted of hydrogel (H) alone as a negative control, and the other three conditions were bFGF-containing hydrogel (HB), human fibroblast-containing hydrogel (HF), and human fibroblast/bFGF-containing hydrogel (HBF). In the Restylane® group (HGF), the hydrogel was replaced with Restylane® (R, RB, RF, RBF). The gels were implanted subdermally into the back of each nude mouse at four separate sites. Twelve nude mice were used for the hydrogel (n = 6) and Restylane® groups (n = 6). The specimens were harvested 8 weeks after implantation and assessed histomorphometrically, and collagen synthesis was evaluated by RT-PCR. Results: The hydrogel group showed good biocompatibility with the surrounding tissues and stimulated the formation of a fibrous matrix. HBF and HF showed significantly higher soft tissue synthesis compared to H (p < 0.05), and human collagen type I was well expressed in HB, HF, and HBF; HBF showed the strongest expression. The Restylane® filler was surrounded by a fibrous capsule without any soft tissue infiltration from the neighboring tissue, and collagen synthesis within the Restylane® filler could not be observed, even though no inflammatory reactions were observed. Conclusion: This study revealed that HA-based hydrogel alone or hydrogel combined with fibroblasts and/or bFGF can be effectively used for soft tissue augmentation.

BONE REGENERATION WITH MMP SENSITIVE HYALURONIC ACID-BASED HYDROGEL, rhBMP-2 AND NANOPARTICLES IN RAT CALVARIAL CRITICAL SIZE DEFECT(CSD) MODEL (Matrix metalloproteinase(MMP) sensitive hyaluronic acid hydrogel-nanoparticle complex와 rhBMP-2를 이용한 골재생)

  • Nam, Jeong-Hun;Park, Jong-Chul;Yu, Sang-Bae;Chung, Yong-Il;Tae, Gi-Yoong;Kim, Jung-Ju;Park, Yong-Doo;Jahng, Jeong-Won;Lee, Jong-Ho
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.35 no.3
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    • pp.137-145
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    • 2009
  • As an efficient controlled release system for rhBMP-2, a functional nanoparticle-hydrogel complex, incorporated with matrix metalloproteinase(MMP) sensitive peptide cross-linker, was developed and used as a bone transplant. In vivo bone formation was evaluated by soft x-ray, histology, alkaline phosphatase(ALP) activity and mineral contents analysis, based on the rat calvarial critical size defect(8mm in diameter) model. Significantly, effective bone regeneration was achieved with the rhBMP-2 loaded MMP sensitive hyaluronic acid(HA) based hydrogel-Nanoparticles(NP) complex, as compared to only MMP HA, the MMP HA-NP without rhBMP-2, or even with the rhBMP-2. These improvements included the formation pattern of bone and functional marrow, the degree of calcium quantification, and the ALP activity. These results indicate that the MMP sensitive HA with nano-particle complex can be a promising candidate for a new bone defect replacement matrix, and an enhanced rhBMP-2 scaffold.

Biomimetics of the extracellular matrix: an integrated three-dimensional fiber-hydrogel composite for cartilage tissue engineering

  • Coburn, Jeannine;Gibson, Matt;Bandalini, Pierre Alain;Laird, Christopher;Mao, Hai-Quan;Moroni, Lorenzo;Seliktar, Dror;Elisseeff, Jennifer
    • Smart Structures and Systems
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    • v.7 no.3
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    • pp.213-222
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    • 2011
  • The native extracellular matrix (ECM) consists of an integrated fibrous protein network and proteoglycan-based ground (hydrogel) substance. We designed a novel electrospinning technique to engineer a three dimensional fiber-hydrogel composite that mimics the native ECM structure, is injectable, and has practical macroscale dimensions for clinically relevant tissue defects. In a model system of articular cartilage tissue engineering, the fiber-hydrogel composites enhanced the biological response of adult stem cells, with dynamic mechanical stimulation resulting in near native levels of extracellular matrix. This technology platform was expanded through structural and biochemical modification of the fibers including hydrophilic fibers containing chondroitin sulfate, a significant component of endogenous tissues, and hydrophobic fibers containing ECM microparticles.

In vitro Release Characteristics of Nitroglycerin from Microemulsion-Based Hydrogel System for Anal Fissure Treatment

  • Lee, Sang-Kil;Shin, Hyun-Woo;Kang, Myung-Joo;Cho, Seong-Wan;Cho, Jae-Youl;Lee, Jae-Hwi;Choi, Young-Wook
    • Journal of Pharmaceutical Investigation
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    • v.37 no.2
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    • pp.95-99
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    • 2007
  • To develop topical nitroglycerin (NTG) preparation far chronic anal fissure treatment, the release rate of NTG should be controlled carefully. For this, microemulsion was prepared from the phase diagram construction with Cremophor ELP, ethanol and Labrafil $M1944CS^{(R)}$ and the topical gel was prepared by dispersing NTG containing microemulsion into hydrophilic polymers. in viかo release characteristics were evaluated with Franz diffusion cell using cellulose membrane and compared with control hydrogels. The release rate of NTG was followed $1^{st}$ order kinetics and, when comparing the NTG release from control hydrogel with that from the microemulsion-based hydrogel, the NTG release rate was controlled by the content of polymers within continuous phase and the concentration of dispersed phase.

Transvaginal Delivery of Luteinizing Hormone-Releasing Hormone Using Bioadhesive Hydrogel (생체막점착성 하이드로겔을 이용한 황체형성호르몬 유리호르몬의 질점막 수송)

  • Han, Kun;Park, Hee-Beom;Park, Jeong-Sook;Chung, Youn-Bok
    • Journal of Pharmaceutical Investigation
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    • v.27 no.1
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    • pp.15-22
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    • 1997
  • The mucosal route of administration(nasal, buccal, conjunctival and vaginal) has recently been considered as an alternative to parenteral delivery for many peptide drugs because enzymatic degradation of these agents may be partly avoided. The objective of these study was to establish the optimal mucosal administration dosage form of $LHRH/[D-Ala^6]LHRH$, based on presystemic metabolism. We reported previously the peptidase inhibition effect of medium chain fatty acid salts(sodium caprylate, soadium caprate and sodium laurate), EDTA and STDHF on the proteolysis of $LHRH/[D-Ala^6]LHRH$ in rabbit mucosal homgenates. We also reported that EDTA, STDHF and sodium laurate markedly increased the potency of $LHRH/[D-Ala^6]LHRH$ solution applied vaginally. In the present study, by administration of polycarbophil hydrogel containing LHRH the ovulation inducing activity was 3.3 times greater than solution. These results indicate not only peptidase inhibitor but also polycarbophil hydrogel significantly improved the absorption of this drug. The results of this study would provide the feasibility as a rational dosage form for improving bioavailability and self administration of this hydrogel by the vaginal application.

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Drug Release from Ph-sensitive Interpenetrating Polymer Net-works Hydrogel Based on Poly(ethylene glycol) Macromer and Poly (acrylic acid)Prepared by UV Cured Method

  • Kim, In-Sook;Kim, Sung-Ho;Cho, Chong-Su
    • Archives of Pharmacal Research
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    • v.19 no.1
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    • pp.18-22
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    • 1996
  • Acrylate-terminated poly (ethylene glycol) (PEG) macromer was prepared by the reaction of PEG with acryloyl chloride. Photopolymerization of PEG macromer resulted in the formation of cross-linked PEG network. Interpenetrating polymer networks (IPNs) based on PEG and poly(acrylic acid) (PAA) was obtained via template polymerization of AA to the PEG network by UV curing. The swelling degree of the IPNs hydrogel increased with an increase of pH value due to the association-dissociation between carboxylic acid of PAA and either of PEG through hydrogen bounding. The swelling-deswelling behavior proceeded reversibly for the IPNs upon changing pH. Release of indomethacin from the IPNs demonstrated "on-off" regulation with pH fluctuation.

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Thermosensitive Chitosan-based Hydrogel with Growth Factor as Adhesion Barrier (성장인자/키토산이 담지된 온도감응성 하이드로젤의 유착방지제로서의 응용)

  • Park, Jun-Kyu;Nah, Jae-Woon;Choi, Changyong
    • Polymer(Korea)
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    • v.39 no.3
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    • pp.480-486
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    • 2015
  • The adhesion of tissue and organ occur with frequency after surgery. Theomosensitive hydrogel was prepared from poloxamer/chitosan/epidermal growth factor as adhesion barrier agent. The prepared hydrogel showed sol-gel transition temperatures around human temperature and gelation temperature was the faster within 1 min. The hydrogel sustained the release of epidermal grow factor during 7 days. The hydrogel was highly effective for the prevention of tissue and organ adhesion in rat model. The thermosensitive and antibacterial chitosan hydrogel can be useful to consider the anti-adhesion barrier with increased adhesion of organ and sustained release of epidermal growth factor.