Effect of charge type of hydrogel on its dye adsorption capacity and kinetic study

Qiuyu Liang,Mingyu Yin,Shi Feng,Xu Xiang 한국고분자학회 2024 Macromolecular Research Vol.32 No.3

Hydrogel has a wide range of applications in many fields because of its good adsorption capacity. There are many factors affecting the adsorption performance of hydrogels, among which the charge of the gel itself is crucial. This work proposes a method to detect the amount of dye adsorbed by measuring the absorbance of hydrogels. Using this method, polyacrylamide (PAM) hydrogels with different charge types were prepared, and their adsorption performance on Congo red and methylene blue dyes was investigated to elucidate the relationship between the charge carried by the hydrogel itself and the adsorption performance. Experiments show that the adsorption capacity of hydrogel for dyes is closely related to its charge, that is, the hydrogel is more likely to adsorb dye molecules with an opposite charge to the hydrogel and the adsorption behavior conforms to the Freundlich isothermal adsorption model. Taking anionic hydrogel as an example, the adsorption kinetics of methylene blue on anionic hydrogel were further studied, and the kinetic model was in accordance with the pseudo-secondary kinetic model, suggesting that a pseudo-second-order kinetic model is more suitable for the adsorption behavior of anionic hydrogels for methylene blue dye. This work helps researchers better understand the role of the charge of hydrogel in the adsorption process and helps to design more targeted hydrogels.

Poly(methyl vinyl ether-co-maleic acid) Hydrogels Containing Cyclodextrins and Tween 85 for Potential Application as Hydrophobic Drug Delivery Systems

Eneko Larrañeta,Juan Domínguez-Robles,Martha Coogan,Emma Heaney,Sarah A. Stewart,Raghu Raj Singh Thakur,Ryan F. Donnelly 한국고분자학회 2019 Macromolecular Research Vol.27 No.4

Hydrogels have been extensively investigated as a platform for drug delivery. However, their use for the delivery of hydrophobic drugs has been limited by their incompatibility with hydrophobic drug molecules. The chemical modification of the structure of the hydrogels to include hydrophobic moieties has been proven to be a good alternative to increase the stability and solubility of hydrophobic drugs in the polymer matrix of the hydrogel. The inclusion of hydroxypropyl-β-cyclodextrins (HPBCD) and Tween® 85 (T85) within hydrogel matrices has the potential to improve hydrophobic drug loading and release. HPBCD have the ability to host hydrophobic drug molecules in their cone-like structure, forming inclusion complexes through host-guest interactions. On the other hand, T85 is an amphiphilic molecule and, consequently, has the potential to increase hydrophilic drug loading within the hydrogels. In the present work, a new type of hydrogel made from poly(methyl vinyl ether-co-maleic acid) (GAN) and poly(ethylene glycol) (PEG) containing T85 and HPBCD was synthesized for hydrophobic drug release. Hydrogels were based on GAN crosslinked (PEG) and HPBCD and/or T85 via an esterification in the solid state (solvent free). The synthesised hydrogels were characterised using Fourier transform infrared (FTIR) spectroscopy, swelling studies and contact angle measurements. The hydrogels showed swellings ranging from 140 to 180%. The inclusion of T85 in the hydrogels improved the wettability of the materials. On the other hand, the inclusion of HPBCD within the hydrogels decreased the wettability as the contact angle between the hydrogels and water increased with the HPBCD content. Finally, the materials were loaded with an ophthalmic drug, dexamethasone (DX). HPBC-containing hydrogels showed a higher DX uptake and, consequently, also a higher capacity of DX release. On the other hand, T85 containing hydrogels did not show any improvement over the hydrogels containing only GAN and PEG. The hydrogels were able to provide sustained DX release over periods of 6 h.

천연고분자 유도체 Carboxymethyl Chitosan과 Carboxymethyl Cellulose가 포함된 고흡수성 수지의 팽윤 거동

김진,김용문,이기영,이창문 한국키틴키토산학회 2015 한국키틴키토산학회지 Vol.14 No.3

The purpose of this study was to prepare and characterize the superabsorbent polyacrylate hydrogel containing carboxymethyl cellulose (CMC) and carboxymethyl chitosan (CMCS). In addition, cinnamon oil obtained from the inner bark of several trees was added to give antibiotic and anti-inflammatory effects on the hydrogels. The surface morphologies of the superabsorbent hydrogels were observed by scanning electron microscopy (SEM). As the CMCS contents increased in the hydrogel of 0.75 g CMC, the pore size decreased and the pore was uniformly distributed over the whole surface of the hydrogels. Swelling properties of the superabsorbent polyacrylate hydrogel containing CMC and CMCS were investigated at 24 h in distilled water (DW) at room temperature. The polyacrylic acid hydrogel exhibited swelling ability of 131.6 (g/g) at 24 h in DW, whereas as the CMC and CMCS contents were increased in the hydrogels, the swelling ability decreased significantly at the same time. Interestingly, when the amount of CMC and CMCS was 0.75 and 0.1 g, respectively, the higher swelling ability of the hydrogel showed compared with the polyacrylic acid hydrogel. There was no influence of cinnamon on the swelling properties of the hydrogels. In this study, we found that the polyacrylate hydrogels containing CMC, CMCS and cinnamon can show higher swelling ability compared with the polyacrylate hydrogel. Therefore, it can be expected that the more safe and biodegradable superabsorbent hydrogel can be developed by adding biopolymers.

천연고분자 유도체 Carboxymethyl Chitosan과 Carboxymethyl Cellulose가 포함된 고흡수성 수지의 팽윤 거동

김진 ( Jin Kim ),김용문 ( Yong Moon Kim ),이기영 ( Ki Young Lee ),이창문 ( Chang Moon Lee ) 한국키틴키토산학회 2015 한국키틴키토산학회지 Vol.20 No.2

The purpose of this study was to prepare and characterize the superabsorbent polyacrylate hydrogel containing carboxymethyl cellulose (CMC) and carboxymethyl chitosan (CMCS). In addition, cinnamon oil obtained from the inner bark of several trees was added to give antibiotic and anti-inflammatory effects on the hydrogels. The surface morphologies of the superabsorbent hydrogels were observed by scanning electron microscopy (SEM). As the CMCS contents increased in the hydrogel of 0.75 g CMC, the pore size decreased and the pore was uniformly distributed over the whole surface of the hydrogels. Swelling properties of the superabsorbent polyacrylate hydrogel containing CMC and CMCS were investigated at 24 h in distilled water (DW) at room temperature. The polyacrylic acid hydrogel exhibited swelling ability of 131.6 (g/g) at 24 h in DW, whereas as the CMC and CMCS contents were increased in the hydrogels, the swelling ability decreased significantly at the same time. Interestingly, when the amount of CMC and CMCS was 0.75 and 0.1 g, respectively, the higher swelling ability of the hydrogel showed compared with the polyacrylic acid hydrogel. There was no influence of cinnamon on the swelling properties of the hydrogels. In this study, we found that the polyacrylate hydrogels containing CMC, CMCS and cinnamon can show higher swelling ability compared with the polyacrylate hydrogel. Therefore, it can be expected that the more safe and biodegradable superabsorbent hydrogel can be developed by adding biopolymers.

리도카인을 함유하는 마이크로에멀젼 겔의 피부침투성 및 in vivo 마취효과

신현우,이기봉,이상길,최영욱,Shin, Hyun-Woo,Lee, Gi-Bong,Lee, Sang-Kil,Choi, Young-Wook 한국약제학회 2000 Journal of Pharmaceutical Investigation Vol.30 No.4

Several topical preparations containing lidocaine, a widely used local anesthetic agent, have been developed and marketed recently for the treatment of premature ejaculation. In this study, microemulsion(ME)-based hydrogels containing lidocaine were prepared by dispersing ME to hydrogel bases such as Carbopol, sod. alginate, and sod. carboxymethylcellulose. Lidocaine-containing ME was thermodynamically stable over 6 months and had a diameter ranging from 10 to 100 nm. In vitro skin penetration of lidocaine from ME-based hydrogels followed apparent zero-order kinetics. ME-based hydrogel showed higher drug penetration during fifteen minutes after application than alcoholic hydrogel, reference preparation. Tail flick test in rat was introduced to compare in vivo local anesthetic effects of different hydrogels, and the results showed that ME-based hydrogels are superior to other hydrogels. In optical microscopy, recrystallization of lidocaine was observed within 5 min after application of reference hydrogel, but there was no change in ME-based hydrogels even after 30 minnute. These results indicated that ME-based hydrogels had some advantages in skin penetration, anesthetic effect and physical stability compared with alcoholic hydrogels. Finally it is possible to conclude that ME-based hydrogels containing lidocaine is a good topical drug delivery system for the treatment of premature ejaculation.

Bioactive self-healing hydrogel based on tannic acid modified gold nano-crosslinker as an injectable brain implant for treating Parkinson’s disease

Xu Junpeng,Chen Tsai-Yu,Tai Chun-Hwei,Hsu Shan-hui 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Parkinson’s disease (PD) is one of the most common long-term neurodegenerative diseases. Current treatments for PD are mostly based on surgery and medication because of the limitation and challenges in selecting proper biomaterials. In this study, an injectable bioactive hydrogel based on novel tannic acid crosslinker was developed to treat PD.The oxidized tannic acid modified gold nano-crosslinker was synthesized and used to effectively crosslink chitosan for preparation of the bioactive self-healing hydrogel. The crosslinking density, conductivity, self-healing ability, and injectability of the hydrogel were characterized. Abilities of the hydrogel to promote the proliferation and differentiation of neural stem cells (NSCs) were assessed in vitro. Anti-inflammatory property was analyzed on J774A.1 macrophages. The hydrogel was injected in the PD rat model for evaluation of the motor function recovery, electrophysiological performance improvement, and histological repair.The hydrogel exhibited self-healing property and 34G (~ 80 μm) needle injectability. NSCs grown in the hydrogel displayed long-term proliferation and differentiation toward neurons in vitro. Besides, the hydrogel owned strong anti-inflammatory and antioxidative capabilities to rescue inflamed NSCs (~ 90%). Brain injection of the bioactive hydrogel recovered the motor function of PD rats. Electrophysiological measurements showed evident alleviation of irregular discharge of nerve cells in the subthalamic nucleus of PD rats administered with the hydrogel. Histological examination confirmed that the hydrogel alone significantly increased the density of tyrosine hydroxylase positive neurons and fibers as well as reduced inflammation, with a high efficacy similar to drug-loaded hydrogel.The new bioactive hydrogel serves as an effective brain injectable implant to treat PD and a promising biomaterial for developing novel strategies to treat brain diseases.

Biomimetic and Photo Crosslinked Hyaluronic Acid/Pluronic F127 Hydrogels with Enhanced Mechanical and Elastic Properties to be Applied in Tissue Engineering

손상수,Vishnu Revuri,Md. Nurunnabi,곽광수,이용규 한국고분자학회 2016 Macromolecular Research Vol.24 No.3

Biosynthetic hydrogels have proved to be a credible solution in developing cost effective scaffolds with superlative mechanical properties for biomedical applications. Elastic hydrogels have emerged with advanced application possibilities for cartilage tissue regeneration and cell implantation. However, a hydrogel scaffold that mimics the properties of biological tissues in terms of elasticity, provision of favorable environment for cell growth and biocompatibility are rarely reported. In this research, we developed photocrosslinked hyaluronic acid/pluronic F127 (HA/PF) porous hydrogels with exceptional mechanical and water sorption properties. In order to retain the micellar phase of PF in the hydrogels, we restrained their concentrations to 8 wt% in the hydrogel matrices. Further optimization such as duration of photocrosslinking resulted in hydrogel scaffolds with remarkable mechanical properties. Topical and cross-sectional scanning electron microscopy images depicted the dense interconnected porous networks within the hydrogel matrices. Rheology studies confirmed the importance of PF concentrations in obtaining the hydrogels with enhanced toughness and mechanical properties. The results from the microscopic rheology studies were further testified by applying macroscopic mechanical distortions over the hydrogels. Hydrogels with higher PF concentrations restrained the degradations and displayed enhanced mechanical properties. By retaining the micellar structures in the HA/PF hydrogel scaffolds, the polypropylene blocks in PF were able to reversibly fold and unfold to favor the energy dissipation during the mechanical deformation and aid in improving the mechanical properties of the hydrogels. The overall properties of the HA-PF hydrogels show optimum feasibility for hard tissue engineering application.

Development of Hydrogels to Improve the Safety of Yukhoe (Korean Beef Tartare) by Reducing Psychrotrophic Listeria monocytogenes Cell Counts on Raw Beef Surface

Hyemin Oh,Sejeong Kim,Soomin Lee,Jimyeong Ha,Jeeyeon Lee,Yukyung Choi,Yewon Lee,Yujin Kim,Yeongeun Seo,Yohan Yoon 한국축산식품학회 2018 한국축산식품학회지 Vol.38 No.6

This study developed an antimicrobial hydrogel to control Listeria monocytogenes in Yukhoe (Korean beef tartare). Four hydrogels (hydrogel 1: 5% alginate+1% chitosan+0.2% CaCl2, hydrogel 2: 1% κ-carrageenan+1% chitosan, hydrogel 3: 2%κ-carrageenan+1% CaCl2, and hydrogel 4: 2% κ-carrageenan+3% CaCl2) were prepared. The hydrogels then absorbed 0.1% grapefruit seed extract (GSE) and 0.1% citrus extract (CE) for 30, 60, 120, and 240 min to be antimicrobial hydrogels. To select the most effective antimicrobial hydrogel, their swelling ratio (SR) and antilisterial activities were determined. The selected hydrogel (2×2 cm) was then placed on surface of beef (round; 3×3 cm), where L. monocytogenes (ca. 106 CFU/g) were inoculated, and the cell counts were enumerated on PALCAM agar. Among the hydrogels, the SR of hydrogel 1 increased with absorbing time, but other hydrogels showed no significant changes. Antimicrobial hydrogel 1 showed higher (p<0.05) antilisterial activity than other antimicrobial hydrogels, especially for the one absorbed the antimicrobial for 120 min. Thus, the antimicrobial hydrogel 1 absorbed antimicrobials for 120 min was applied on raw beef at 4℃, and reduced (p<0.05) more than 90% of L. monocytogenes on raw beef. These results indicate that antimicrobial hydrogel 1 formulated with 0.1% GSE or 0.1% CE is appropriate to improve the safety of Yukhoe by reducing psychrotrophic L. monocytogenes cell counts on raw beef.

Catechol-rich gelatin hydrogels <i>in situ</i> hybridizations with silver nanoparticle for enhanced antibacterial activity

Le Thi, Phuong,Lee, Yunki,Hoang Thi, Thai Thanh,Park, Kyung Min,Park, Ki Dong Elsevier 2018 Materials science & engineering. C, Materials for Vol.92 No.-

<P><B>Abstract</B></P> <P>Recently, the interest in antimicrobial hydrogels with impregnated antibacterial agents has significantly increased because of their ability to combat infection in biomedical applications, including wound management, tissue engineering, and biomaterial surface coating. Among these antibacterial reagents, silver nanoparticles (AgNP) show good antibacterial activity against both gram-negative and gram-positive bacteria, including highly multi-resistant strains. However, the entrapment of AgNP within a hydrogel matrix is often associated with toxicity issues because of the use of chemical reductants (<I>e.g.</I>, commonly sodium borohydride), burst leaching, or unwanted agglomeration of AgNP in the absence of surfactants or stabilizers. In this study, we present catechol-rich gelatin hydrogels with <I>in situ</I> hybridization of AgNP for enhanced antimicrobial activities. AgNP were formed through a redox reaction between silver ions and the catechol moieties of a gelatin derivative polymer, without the addition of any chemical reductants. The AgNP with an average size of 20 nm were entrapped within hydrogel matrices and showed sustained release from the hydrogel matrix (8.7% for 14 days). The resulting hydrogels could kill both gram-negative and gram-positive bacteria, depending on the amount of AgNP released from the hydrogels and did not have a significant influence on mammalian cell viability. We believe that our catechol-rich hydrogels <I>in situ</I> hybridizations with AgNP have great potential for biomedical applications, such as wound management and surface coating, because of their excellent antibacterial activities and biocompatibility.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Silver nanoparticles incorporation (AgNP) impart the antimicrobial properties to injectable gelatin hydrogel. </LI> <LI> AgNP was <I>in situ</I> synthesized within the hydrogel matrix, with controllable size and sustained release. </LI> <LI> The nanocomposite hydrogels significantly inhibited bacterial growth without affecting viability of mammalian cells. </LI> <LI> These <I>in situ</I> forming GHD/AgNP hydrogels are potential for a wide range of biomedical applications. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>A simple method using catecholic chemistry to prepare an injectable nanocomposite hydrogel with excellent antimicrobial activities. Silver nanoparticles (AgNP) were <I>in situ</I> synthesized within the gelatin hydrogel matrix, during the hydrogelation without use of toxic reductants. The hydrogels inhibited bacterial growth while not affected the viability of mammalian cells. This injectable hydrogel is easy to fabricate <I>in vivo</I> with promising potential for biomedical applications, where advantageous antibacterial activities are required to reduce the infection rates, for example wound dressing, tissue adhesives, biomaterial surface coatings …</P> <P>[DISPLAY OMISSION]</P>

Cellular infiltration in an injectable sulfated cellulose nanocrystal hydrogel and efficient angiogenesis by VEGF loading

민기윤,태기융 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Background Cellular infiltration and angiogenesis into implanted biomaterial scaffolds are crucial for successful host tissue integration and tissue regeneration. Cellulose nanocrystal (CNC) is a nano-sized cellulose derivative, which can form an injectable physical gel with salts. Sulfate groups of sulfated CNC (CNC-S) can act as a binding domain to various growth factors and cytokines with a heparin-binding domain for sustained release of them. Vascular endothelial growth factor (VEGF) can promote the proliferation of endothelial cells and angiogenesis. In this study, VEGF-loaded CNC-S hydrogel was evaluated as an injectable scaffold that can induce cellular infiltration and angiogenesis. Methods CNC-S was hydrolyzed to get desulfated CNC (CNC-DS), which was used as a negative control group against CNC-S. Both CNC-S and CNC-DS hydrogels were prepared and compared in terms of biocompatibility and VEGF release. The hydrogels with or without VEGF loading were subcutaneously injected into mice to evaluate the biocompatibility, cellular infiltration, and angiogenesis induction of the hydrogels. Results Both hydrogels possessed similar stability and shear-thinning behavior to be applicable as injectable hydrogels. However, CNC-S hydrogel showed sustained release (until 8 weeks) of VEGF whereas CNC-DS showed a very fast release of VEGF with a large burst. Subcutaneously injected CNC-S hydrogel showed much enhanced cellular infiltration as well as better biocompatibility with milder foreign body response than CNC-DS hydrogel. Furthermore, VEGFloaded CNC-S hydrogel induced significant angiogenesis inside the hydrogel whereas VEGF-loaded CNC-DS did not. Conclusion CNC-S possesses good properties as a biomaterial including injectability, biocompatibility, and allowing cellular infiltration and sustained release of growth factors. VEGF-loaded CNC-S hydrogel exhibited efficient angiogenesis inside the hydrogel. The sulfate group of CNC-S was a key for good biocompatibility and the biological activities of VEGF-loaded CNC hydrogel.