{"title":"Potential of a CO2-Responsive supramolecular drug-carrier system as a safer and more effective treatment for cancer","authors":"Enyew Alemayehu Bayle , Fasih Bintang Ilhami , Jem-Kun Chen , Chih-Chia Cheng","doi":"10.1016/j.mtbio.2024.101319","DOIUrl":null,"url":null,"abstract":"<div><div>We combined carbon dioxide (CO<sub>2</sub>)-responsive cytosine-containing rhodamine 6G (Cy-R6G) as a hydrophobic anticancer agent with hydrogen-bonded cytosine-functionalized polyethylene glycol (Cy-PEG) as a hydrophilic supramolecular carrier to construct a CO<sub>2</sub>-responsive drug delivery system, with the aim of enhancing the responsiveness of the system to the tumor microenvironment and thus the overall effectiveness of anticancer therapy. Due to self-complementary hydrogen bonding interactions between cytosine units, Cy-R6G and Cy-PEG co-assemble in water to form spherical-like nanogels, with Cy-R6G effectively encapsulated within the nanogels. The nanogels exhibit several distinctive physical features, such as widely tunable nanogel size and drug loading capacity for Cy-R6G, intriguing fluorescence properties, high co-assembled structural stability in normal aqueous environments, enhanced anti-hemolytic characteristics, sensitive dual CO<sub>2</sub>/pH-responsive behavior, and precise and easily controllable CO<sub>2</sub>-induced release of Cy-R6G. Cytotoxicity assays clearly indicated that, due to the presence of cytosine receptors on the surface of cancer cells, Cy-R6G-loaded nanogels exert selective cytotoxicity against cancer cells in pristine culture medium, but do not affect the viability of normal cells. Surprisingly, in CO<sub>2</sub>-rich culture medium, Cy-R6G-loaded nanogels exhibit a further significant enhancement in cytotoxicity against cancer cells, and remain non-cytotoxic to normal cells. More importantly, a series of <em>in vitro</em> experiments demonstrated that compared to pristine culture medium, CO<sub>2</sub>-rich culture medium promotes more rapid selective internalization of Cy-R6G-loaded nanogels into cancer cells through cytosine-mediated macropinocytosis and thus accelerates the induction of apoptosis. Therefore, this newly developed system provides novel avenues for the development of highly effective CO<sub>2</sub>-responsive drug delivery systems with potent anticancer capabilities.</div></div>","PeriodicalId":18310,"journal":{"name":"Materials Today Bio","volume":"29 ","pages":"Article 101319"},"PeriodicalIF":8.7000,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Materials Today Bio","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2590006424003806","RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, BIOMEDICAL","Score":null,"Total":0}
引用次数: 0
Abstract
We combined carbon dioxide (CO2)-responsive cytosine-containing rhodamine 6G (Cy-R6G) as a hydrophobic anticancer agent with hydrogen-bonded cytosine-functionalized polyethylene glycol (Cy-PEG) as a hydrophilic supramolecular carrier to construct a CO2-responsive drug delivery system, with the aim of enhancing the responsiveness of the system to the tumor microenvironment and thus the overall effectiveness of anticancer therapy. Due to self-complementary hydrogen bonding interactions between cytosine units, Cy-R6G and Cy-PEG co-assemble in water to form spherical-like nanogels, with Cy-R6G effectively encapsulated within the nanogels. The nanogels exhibit several distinctive physical features, such as widely tunable nanogel size and drug loading capacity for Cy-R6G, intriguing fluorescence properties, high co-assembled structural stability in normal aqueous environments, enhanced anti-hemolytic characteristics, sensitive dual CO2/pH-responsive behavior, and precise and easily controllable CO2-induced release of Cy-R6G. Cytotoxicity assays clearly indicated that, due to the presence of cytosine receptors on the surface of cancer cells, Cy-R6G-loaded nanogels exert selective cytotoxicity against cancer cells in pristine culture medium, but do not affect the viability of normal cells. Surprisingly, in CO2-rich culture medium, Cy-R6G-loaded nanogels exhibit a further significant enhancement in cytotoxicity against cancer cells, and remain non-cytotoxic to normal cells. More importantly, a series of in vitro experiments demonstrated that compared to pristine culture medium, CO2-rich culture medium promotes more rapid selective internalization of Cy-R6G-loaded nanogels into cancer cells through cytosine-mediated macropinocytosis and thus accelerates the induction of apoptosis. Therefore, this newly developed system provides novel avenues for the development of highly effective CO2-responsive drug delivery systems with potent anticancer capabilities.
期刊介绍:
Materials Today Bio is a multidisciplinary journal that specializes in the intersection between biology and materials science, chemistry, physics, engineering, and medicine. It covers various aspects such as the design and assembly of new structures, their interaction with biological systems, functionalization, bioimaging, therapies, and diagnostics in healthcare. The journal aims to showcase the most significant advancements and discoveries in this field. As part of the Materials Today family, Materials Today Bio provides rigorous peer review, quick decision-making, and high visibility for authors. It is indexed in Scopus, PubMed Central, Emerging Sources, Citation Index (ESCI), and Directory of Open Access Journals (DOAJ).