<p>Synthesis, Characterization, and Toxicity Assessment of Pluronic F127-Functionalized Graphene Oxide on the Embryonic Development of Zebrafish (<em>Danio rerio</em>)</p>

Abstract

Background In the current literature, there are ongoing debates on the toxicity of graphene oxide (GO) that demonstrate contradictory findings regarding its toxicity profile. As a potential drug carrier, these findings are very concerning due to the safety concerns in humans, as well as the dramatic rise of GO being excreted into the environment. Therefore, there is an imperative need to mitigate the potential toxicity of GO to allow for a safer application in the future. Purpose The present study aims to address this issue by functionalizing GO with Pluronic F127 (PF) as a means to mitigate toxicity and resolve the biocompatibility of GO. Although results from previous studies generally indicated that Pluronic functionalized GO exhibits relatively low toxicity to living organisms, reports that emphasize on its toxicity, particularly during embryonic developmental stage, are still scarce. Methods In the present study, two different sizes of native GO samples, GO and NanoGO, as well as PF-functionalized GO, GO-PF and NanoGO-PF, were prepared and characterized using DLS, UV-Vis, Raman spectroscopy, FTIR, and FESEM analyses. Toxicological assessment of all GO samples (0–100 µg/mL) on zebrafish embryonic developmental stages (survival, hatching and heart rates, and morphological changes) was recorded daily for up to 96 hours post-fertilization (hpf). Results The toxicity effects of each GO sample were observed to be higher at increasing concentrations and upon prolonged exposure. NanoGO demonstrated lower toxicity effects compared to GO. GO-PF and NanoGO-PF were also found to have lower toxicity effects compared to native GO samples. GO-PF showed the lowest toxicity response on zebrafish embryo. Conclusion These findings highlight that toxicity is dependent on the concentration, size, and exposure period of GO. Functionalization of GO with PF through surface coating could potentially mitigate the toxicity effects of GO in embryonic developmental stages, but further investigation is warranted for broader future applications.

Promising Graphene-Based Nanomaterials and Their Biomedical Applications and Potential Risks: A Comprehensive Review

“…Several studies have revealed that the modification of copolymers can improve the biocompatibility of GBNs in vivo . For example, when the unoxidized graphene surface mosaic is pluronic, the toxicity in vivo is further lower than GO . Moreover, the modification of the copolymer offers a safe and reliable option for the application of GBNs in the biomedical field.…”

“…For example, when the unoxidized graphene surface mosaic is pluronic, the toxicity in vivo is further lower than GO. 195 Moreover, the modification of the copolymer offers a safe and reliable option for the application of GBNs in the biomedical field.…”

The effects of the oral administration of graphene oxide on the gut microbiota and ultrastructure of the colon of mice

“…With the further application of GO, its biotoxicity and safety have become the focus of research. A study reported that nano-scale GO has a dose-dependent toxic effect on zebrafish embryonic development (15). Some scholars had found that the oral administration of GO nanoparticles causes various behavioral and developmental defects in the offspring of drosophila (16).…”

Biocompatibility Study of Curcumin-Loaded Pluronic F127 Nanoformulation (NanoCUR) against the Embryonic Development of Zebrafish (Danio rerio)

“…All these features make zebrafish attractive as a model organism in studying toxicology with simplicity by assessing their developmental and morphological changes. Furthermore, zebrafish embryos have also been widely used, and have been considered highly effective in screening the toxicity of nanomaterials [ 27 , 28 ], as well as phytochemicals extracted from plants, such as Piper sarmentosum [ 29 ]. The salient features of the embryos, which are their greater sensitivity to undesired harmful effects and their transparent nature, make it easy for the embryos to be analyzed for the effects of toxicants on their organs, such as the heart, brain, liver, kidney, and others.…”

“…Therefore, it allows direct observation of the periods of development and the assessment of the endpoints of toxicity. Testing using nanomaterials on zebrafish embryos also allows several parameters to be varied such as concentration, size, chemical composition, and time of exposure [ 27 , 28 , 30 ]. A previous study using zinc oxide nanoparticles on zebrafish embryos was not only able to assess embryo toxicity, but was also able to analyze the antioxidant defence system, ROS, and DNA damage [ 31 ].…”