Succinoglycan dialdehyde-reinforced gelatin hydrogels with toughness and thermal stability

et al. 2020

Self Cite

Hydrogel materials with a gel-sol conversion due to external environmental changes have potential applications in a wide range of fields, including controlled drug delivery. Succinoglycans are anionic extracellular polysaccharides produced by various bacteria, including Sinorhizobium species, which have diverse applications. In this study, the rheological analysis confirmed that succinoglycan produced by Sinorhizobium meliloti Rm 1021 binds weakly to various metal ions, including Fe2+ cations, to maintain a sol form, and binds strongly to Fe3+ cations to maintain a gel form. The Fe3+-coordinated succinoglycan (Fe3+-SG) hydrogel was analyzed by attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, circular dichroism (CD), and field-emission scanning electron microscopy (FE-SEM). Our results revealed that the Fe3+ cations that coordinated with succinoglycan were converted to Fe2+ by a reducing agent and visible light, promoting a gel-sol conversion. The Fe3+-SG hydrogel was then successfully used for controlled drug delivery based on gel-sol conversion in the presence of reducing agents and visible light. As succinoglycan is nontoxic, it is a potential material for controlled drug delivery.

Section: Introductionmentioning

confidence: 99%

Preparation of Succinoglycan Hydrogel Coordinated With Fe3+ Ions for Controlled Drug Delivery

Jeong

et al. 2020

Self Cite

“…This result is exhibited because SG is able to maintain its physical consistency, even under extreme conditions [ 19 , 20 ]. It has been reported that the addition of SG or modified-SG increases the mechanical strength of the hydrogel [ 17 , 47 ]. Therefore, these results indicate that SG effectively enhanced the mechanical strength of the Fe 3+ crosslinked layered SG/CMC IPN gels.…”

Section: Resultsmentioning

confidence: 99%

“…A three-dimensional interconnected porous structure was observed on the cross-section surface of the SG gel. These pores can be related to the degree of cross-linking and mechanical strength [ 47 ]. The SEM image of the CMC gel shows an increase in the surface area of the hydrogel due to the coarse, small, and frequent porous structure.…”

Section: Resultsmentioning

confidence: 99%

pH-Responsive Succinoglycan-Carboxymethyl Cellulose Hydrogels with Highly Improved Mechanical Strength for Controlled Drug Delivery Systems

Shin

et al. 2021

Self Cite

Carboxymethyl cellulose (CMC)-based hydrogels are generally superabsorbent and biocompatible, but their low mechanical strength limits their application. To overcome these drawbacks, we used bacterial succinoglycan (SG), a biocompatible natural polysaccharide, as a double crosslinking strategy to produce novel interpenetrating polymer network (IPN) hydrogels in a non-bead form. These new SG/CMC-based IPN hydrogels significantly increased the mechanical strength while maintaining the characteristic superabsorbent property of CMC-based hydrogels. The SG/CMC gels exhibited an 8.5-fold improvement in compressive stress and up to a 6.5-fold higher storage modulus (G′) at the same strain compared to the CMC alone gels. Furthermore, SG/CMC gels not only showed pH-controlled drug release for 5-fluorouracil but also did not show any cytotoxicity to HEK-293 cells. This suggests that SG/CMC hydrogels could be used as future biomedical biomaterials for drug delivery.

“…Then, the swollen hydrogel was taken out of the buffer and weighed after removing excess surface solution by using filter paper. The swelling ratio was obtained based on the following equation [ 26 ]:

where W S and W d represent the weight of the swollen and dried hydrogels, respectively. Each experiment was conducted three times.…”

Section: Methodsmentioning

confidence: 99%

Fabrication of Flexible pH-Responsive Agarose/Succinoglycan Hydrogels for Controlled Drug Release

Hong

et al. 2021

Self Cite

Agarose/succinoglycan hydrogels were prepared as pH-responsive drug delivery systems with significantly improved flexibility, thermostability, and porosity compared to agarose gels alone. Agarose/succinoglycan hydrogels were made using agarose and succinoglycan, a polysaccharide directly isolated from Sinorhizobium meliloti. Mechanical and physical properties of agarose/succinoglycan hydrogels were investigated using various instrumental methods such as rheological measurements, attenuated total reflection–Fourier transform infrared (ATR-FTIR) spectroscopic analysis, X-ray diffraction (XRD), and field-emission scanning electron microscopy (FE-SEM). The results showed that the agarose/succinoglycan hydrogels became flexible and stable network gels with an improved swelling pattern in basic solution compared to the hard and brittle agarose gel alone. In addition, these hydrogels showed a pH-responsive delivery of ciprofloxacin (CPFX), with a cumulative release of ~41% within 35 h at pH 1.2 and complete release at pH 7.4. Agarose/succinoglycan hydrogels also proved to be non-toxic as a result of the cell cytotoxicity test, suggesting that these hydrogels would be a potential natural biomaterial for biomedical applications such as various drug delivery system and cell culture scaffolds.