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

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2049
Author(s):  
Yiluo Hu ◽  
Yohan Kim ◽  
Inki Hong ◽  
Moosung Kim ◽  
Seunho Jung

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.

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3197
Author(s):  
Younghyun Shin ◽  
Dajung Kim ◽  
Yiluo Hu ◽  
Yohan Kim ◽  
In Ki Hong ◽  
...  

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.


Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 977 ◽  
Author(s):  
Yiluo Hu ◽  
Daham Jeong ◽  
Yohan Kim ◽  
Seonmok Kim ◽  
Seunho Jung

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.


2015 ◽  
Vol 6 (22) ◽  
pp. 4144-4153 ◽  
Author(s):  
Ziguang Zhao ◽  
Feiyan Zhu ◽  
Xiaozhong Qu ◽  
Qiuhua Wu ◽  
Qian Wang ◽  
...  

In this study, we have successfully designed and fabricated pH-responsive polymeric Janus hollow spheres for controlled drug release.


2015 ◽  
Vol 3 (46) ◽  
pp. 9033-9042 ◽  
Author(s):  
Mengni He ◽  
Jiajia Zhou ◽  
Jian Chen ◽  
Fangcai Zheng ◽  
Dongdong Wang ◽  
...  

Controlled drug release is a promising approach for cancer therapy due to its merits of reduced systemic toxicity and enhanced antitumor efficacy.


RSC Advances ◽  
2020 ◽  
Vol 10 (46) ◽  
pp. 27305-27314
Author(s):  
Yolanda Salinas ◽  
Michael Kneidinger ◽  
Cristina Fornaguera ◽  
Salvador Borrós ◽  
Oliver Brüggemann ◽  
...  

Bottle-brush polyphosphazenes as dual, thermosensitive and pH responsive gatekeepers for mesoporous silica nanoparticles, and their use in controlled drug release.


2014 ◽  
Vol 2 (33) ◽  
pp. 5409-5418 ◽  
Author(s):  
Bo Yu ◽  
Xiaoling Li ◽  
Wenjie Zheng ◽  
Yanxian Feng ◽  
Yum-Shing Wong ◽  
...  

A cancer-targeted and structure-transformable drug delivery system has been constructed, which displays enhanced anticancer efficacy and exhibits the characteristics of shape transformation and pH-controlled drug release under acidifying cell organelles.


Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3950
Author(s):  
Minmin Chen ◽  
Jinxia Hu ◽  
Cancan Bian ◽  
Chenghao Zhu ◽  
Chen Chen ◽  
...  

As a drug delivery system (DDS), traditional mesoporous silica nanoparticles (MSNs) suffer from bioaccumulation in vivo and premature drug release in systemic circulation due to low degradation rate and lack of protective gatekeeper. Herein, we developed a safe and intelligent DDS with characteristics of pH-responsive biodegradation and controlled drug release based on mesoporous silica composite nanoparticles (MSCNs) capped with ZnO quantum dots (ZnO QDs). Acidic degradable MSCNs were successfully synthesized by doping Ca2+ and PO43− into the MSNs’ framework. The in vitro doxorubicin hydrochloride (DOX) release was inhibited at neutral pH 7.4 but triggered significantly at pH 5.0 due to the dissociation of ZnO caps. The internalization behavior and cytotoxicity of 4T1 cells indicated MSCNs-ZnO could efficiently deliver DOX into the cells with significant antitumor activity. Such a DDS with pH-responsive biodegradation and controlled drug release has promising potential for cancer therapy.


2018 ◽  
Vol 25 (25) ◽  
pp. 3036-3057 ◽  
Author(s):  
Xiao Sun ◽  
Guilong Zhang ◽  
Zhengyan Wu

According to the differences of microenvironments between tumors and healthy tissues, if the anticancer drugs or magnetic resonance contrast agents (MRCAs) can be controlled to precisely match physiological needs at targeted tumor sites, it is expected to acquire better therapeutic efficacy and more accurate diagnosis. Over the decade, stimuli-responsive nanomaterials have been a research hotspot for cancer treatment and diagnosis because they show many excellent functions, such as in vivo imaging, combined targeting drug delivery and systemic controlled release, extended circulation time, etc. Among the various stimuli nanosystems, pH-stimuli mode is regarded as the most general strategy because of solid tumors acidosis. When exposed to weakly acidic tumor microenvironment, pH-responsive nanoplatforms can generate physicochemical changes for their structure and surface characteristics, causing drug release or contrast enhancement. In this review, we focused on the designs of various pH-responsive nanoplatforms and discussed the mechanisms of controlled drug release or switch on-off in MRCAs. This review also discussed the efficacy of cellular internalization for these nanoplatforms via endocytosis of acidic tumor cell. Meanwhile, nanoplatforms response to acidic intracellular pH (such as endosome, lysosome) are discussed, along with approaches for improving drug release performance and magnetic resonance contrast enhancement. A greater understanding of these pH-responsive nanoplatforms will help design more efficient nanomedicine to address the challenges encountered in conventional diagnosis and chemotherapy.


2020 ◽  
Vol 17 ◽  
Author(s):  
Dan Zou ◽  
Yajun Weng ◽  
Ping Yang

Background: How to achieve high targeting efficiency for drug delivery system is still one of the most important issues that tumor diagnosis and non-surgical therapies faced. Although nanoparticle-based drug delivery system made an amount of progress in extending circulation time, improving targetability, controlled drug release etc., yet the targeting efficiency remained low, and the development was limited to reduce side effects with overall survival rates unchanged or improved a little. Objective: This paper aims to review current researches on the cell-driven drug delivery systems, and discuss the potential obstacles and directions for cell-based cancer therapies and diagnosis. Methods: More than one hundred references were collected, and this paper focused on red blood cells, monocytes, macrophages, neutrophils, natural killer cells, T lymphocytes, mesenchymal stem cells, cell membrane, artificial cells and extracellular vesicles, then summarized 1) the utilizable properties, 2) balancing cargo-loading amounts and cell function, 3) cascade strategies for targetability improvement. Main findings: circulatory cells and their derivatives were featured by good biocompatibility, long circulation time in blood, unique chemo-migration and penetration ability. On the base of backpack and encapsulation approach, cargo loading amounts and cell function could be balanced through regulating membrane receptors, particle material/size/shape/structure and incubation temperature, etc. The cell-driven drug delivery system met most of the demands that nanoparticle-based delivery system failed to for effective tumortropic delivery. Conclusion: Despite of new challenges, cell-driven drug delivery system generally brought great benefits to and shed a light on for cancer therapy and diagnosis.


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