pH regulates many cellular processes and is also an indicator of disease progression. Therefore, pH responsive materials often serve as either tools in the fundamental understanding of cell biology or medicines for disease diagnosis and therapy. While gold nanoparticles have found broad biomedical applications, very few of them exhibit pH dependent interactions with live cells in a native biological environment due to nonspecific serum protein adsorption. Herein, we report that by coating luminescent gold nanoparticles with a natural peptide, glutathione and the simplest stable aminothiol, cysteamine, we enabled the nanoparticles to exhibit not only high resistance to serum protein adsorption but also pH dependent adsorption onto the live cell membrane in the presence of serum proteins. Incorporating this pH dependent membrane adsorption behavior into gold nanoparticles could potentially catalyze new biomedical applications of metal nanoparticles in the fundamental understanding of biological processes as well as disease diagnosis and therapy, where pH changes are involved.
The success of nanomedicines in the clinic depends on our comprehensive understanding of nano–bio interactions in tumor microenvironments, which are characterized by dense leaky microvasculature and acidic extracellular pH (pHe) values. Herein, we investigated the accumulation of ultrasmall renal-clearable gold NPs (AuNPs) with and without acidity targeting in xenograft mouse models of two prostate cancer types, PC-3 and LNCaP, with distinct microenvironments. Our results show that both sets of AuNPs could easily penetrate into the tumors but their uptake and retention were mainly dictated by the tumor microvasculature and the enhanced permeability and retention effect over the entire targeting process. On the other hand, increased tumor acidity indeed enhanced the uptake of AuNPs with acidity targeting, but only for a limited period of time. By making use of simple surface chemistry, these two effects can be synchronized in time for high tumor targeting, opening new possibilities to further improve the targeting efficiencies of nanomedicines.
The success of nanomedicines in the clinic depends on our comprehensive understanding of nanobio interactions in tumor microenvironments, which are characterized by dense leaky microvasculature and acidic extracellular pH (pH e ) values. Herein, we investigated the accumulation of ultrasmall renal-clearable gold NPs (AuNPs) with and without acidity targeting in Correspondence to: Xiankai Sun; Jie Zheng. Supporting information for this article can be found under: http://dx
Background & Aims: Human intestinal enteroids (HIEs) are gaining recognition as physiologically relevant models of the intestinal epithelium. While HIEs from adults are used extensively in biomedical research, few studies have used HIEs from infants. Considering the dramatic developmental changes that occur during infancy, it is important to establish models that represent the infant intestinal anatomy and physiological responses. Methods: We established jejunal HIEs from infant surgical samples and performed comparisons to jejunal HIEs from adults using RNA sequencing (RNA-Seq) and morphologic analyses. We validated differences in key pathways through functional studies and determined if these cultures recapitulate known features of the infant intestinal epithelium. Results: RNA-Seq analysis showed significant differences in the transcriptome of infant and adult HIEs, including differences in genes and pathways associated with cell differentiation and proliferation, tissue development, lipid metabolism, innate immunity, and biological adhesion. Validating these results, we observed as higher expression of enterocytes, goblet cells and enteroendocrine cells in differentiated infant HIEs, and greater numbers of proliferative cells in undifferentiated cultures. Compared to adult HIEs, infant HIEs portray characteristics of an immature gastrointestinal epithelium including significantly shorter cell height, lower epithelial barrier integrity, and lower innate immune responses to infection with an oral poliovirus vaccine. Conclusions: HIEs established from infant intestinal tissues reflect characteristics of the infant gut and are distinct from adult cultures. Our data support the use of infant HIEs as an ex-vivo model to advance studies of infant-specific diseases and drug discovery for this population.
Aims: To evaluate the performance of two matrix-assisted laser desorption/ionization–time-of-flight mass spectrometry platforms to identify molds isolated from clinical specimens. Methods: Fifty mold isolates were analyzed on Bruker Biotyper® and Vitek® MS platforms. Two Bruker Biotyper extraction protocols were assessed alongside the US FDA-approved extraction protocol for Vitek MS. Results: The Bruker Biotyper modified NIH-developed extraction protocol correctly identified more isolates than Bruker’s protocol (56 vs 33%). For species in the manufacturers’ databases, Vitek MS correctly identified 85% of isolates, with 8% misidentifications. The Bruker Biotyper identified 64%, with no misidentifications. For isolates not in the databases, the Bruker Biotyper did not misidentify any, and Vitek MS misidentified 36%. Conclusion: Both the Vitek MS and Bruker Biotyper accurately identified the fungal isolates, however Vitek MS was more likely to misidentify isolates than the Bruker Biotyper.
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