Bioinspired Biomaterials by Unknown

Author:Unknown
Language: eng
Format: epub
ISBN: 9789811532580
Publisher: Springer Singapore

8.2 INPs as Carriers

8.2.1 Gold

AuNPs are one of the most promising tools that can serve as great carriers for drug, gene, and even other bio-applicable materials [26–28]. One of the representative properties of AuNPs used for DDS is their stability, especially in pH responsiveness, as compared with other metal materials. Bhang et al. developed manganese-incorporated AuNPs (MnAuNPs), where they utilized AuNPs as nanocarriers for manganese [29]. The MnAuNPs were fabricated by reducing both Mn2+ and Au3+ with sodium borohydride (NaBH4) in the presence of polyvinylpyrrolidone. As they treated pheochromocytoma 12 (PC12) cells with MnAuNPs, MnAuNPs could be delivered to the PC12 cells via endocytosis, followed by the release of Mn2+ ions into the endosome (Fig. 8.1a). Mn can relatively easy react with hydrogen, as compared with Au, due to its low standard reduction potential of −1.18 V, in contrast to that of Au of +0.7 V [30]. Therefore, Mn2+ can be released from the MnAuNPs while in the endosomes, which have low pH conditions. Controlled Mn2+ release allowed PC12 cells to have enhanced neuronal differentiative efficacy without cytotoxicity (Fig. 8.1b, c), because this system prohibits the overdose of Mn2+ release and ATP depletion in preventing active transport, which cause PC12 cells’ apoptosis [31, 32]. In conclusion, Au in MnAuNPs served as carriers for the pH-triggered, intracellular delivery of Mn ions to stimulate neuronal differentiation of PC12 cells (Fig. 8.1d).

Fig. 8.1Applications of novel modified AuNPs for bio-application. Schematics of (a) pH-triggered intracellular delivery of Mn2+ through MnAuNPs for the neuronal differentiation of PC12 cells. (b) Western blot analysis for caspase-3 protein expression, which is a representative apoptotic marker, and its quantification at 24 h (n = 5, ∗p < 0.01 versus Mn2+ group). (c) Neutral red assay for cell viability of PC12 cells at 24 h (n = 5, ∗p < 0.01 versus no-Mn2+ group). (d) Neuronal differentiation of PC12 cells evaluated by immunocytochemistry for β-tubulin III (green) and nucleus (blue). (Reprinted from Biomaterials, 55, Bhang et al., pH-triggered release of manganese from MnAu nanoparticles that enables cellular neuronal differentiation without cellular toxicity, 39, 2015, with permission from Elsevier). (e) Scheme of GNS-pHLIP for enhanced cancer therapy with CT and PA imaging. (f) The tumor temperature variance during the irradiation of laser in each group in vivo. (Reprinted with permission from Tian et al., ACS applied materials & interfaces, 9 (3) pp. 2114–2122)

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.