Abstract:Alkaline phosphatase (ALP) is an essential enzyme and widely distributes in a variety of tissues. To date, various nanomaterial and small-molecule fluorescent probes for ALP have been constructed successfully, but the emission wavelengths of these probes are in the ultraviolet or visible range, which is not beneficial for bioimaging. Herein, a hemicyanine-based near-infrared (NIR) fluorescent probe named CyP is first synthesized and used to detect ALP activity. The characteristics of probe CyP are as follows: … Show more
“…The fluorophore has demonstrated its suitability for fluorescence imaging of various biomolecules, such as the detection of β-Lactamase in Staphylococcus aureus 20 , the detection of nitroxyl (HNO) 21 and palladium 22 in live cells, the detection of nitroreductase 23 , γ-glutamyl transpeptidase 24 and tyrosinase 25 in zebrafish. More recently, the hemicyanine NIR dyes have been used for in vivo detection of cysteine 26,27 , alkaline phosphatase in tumor models 28–30 , superoxide radical anion 31 , hydrogen sulphide 32 , hydrogen polysulfides 33 and γ-glutamyl transpeptidase 34 in mice models.Figure 1Fluorescence detection of cellular senescence using the NIR-BG probe. λ ex = 680 nm; λ em = 708 nm.…”
Detection of cellular senescence is important not only in the study of senescence in various biological systems, but also in various practical applications such as image-guided surgical removal of senescent cells, as well as the monitoring of drug-responsiveness during cancer therapies. Due to the lack of suitable imaging probes for senescence detection, particularly in living subjects, we have developed an activatable near-infrared (NIR) molecular probe with far-red excitation, NIR emission, and high “turn-on” ratio upon senescence-associated β-galactosidase (SABG) activation. We present here the first successful demonstration of NIR imaging of DNA damage-induced senescence both in vitro and in human tumor xenograft models.
“…The fluorophore has demonstrated its suitability for fluorescence imaging of various biomolecules, such as the detection of β-Lactamase in Staphylococcus aureus 20 , the detection of nitroxyl (HNO) 21 and palladium 22 in live cells, the detection of nitroreductase 23 , γ-glutamyl transpeptidase 24 and tyrosinase 25 in zebrafish. More recently, the hemicyanine NIR dyes have been used for in vivo detection of cysteine 26,27 , alkaline phosphatase in tumor models 28–30 , superoxide radical anion 31 , hydrogen sulphide 32 , hydrogen polysulfides 33 and γ-glutamyl transpeptidase 34 in mice models.Figure 1Fluorescence detection of cellular senescence using the NIR-BG probe. λ ex = 680 nm; λ em = 708 nm.…”
Detection of cellular senescence is important not only in the study of senescence in various biological systems, but also in various practical applications such as image-guided surgical removal of senescent cells, as well as the monitoring of drug-responsiveness during cancer therapies. Due to the lack of suitable imaging probes for senescence detection, particularly in living subjects, we have developed an activatable near-infrared (NIR) molecular probe with far-red excitation, NIR emission, and high “turn-on” ratio upon senescence-associated β-galactosidase (SABG) activation. We present here the first successful demonstration of NIR imaging of DNA damage-induced senescence both in vitro and in human tumor xenograft models.
“…CyOH was synthesized using a method described in previous studies. 33,37 Prior to CyOH synthesis, compound 3 as an intermediate was prepared from compound 1 and compound 2 by following the synthetic route depicted in Scheme S1. † The puried compound 3 (1.0 g), resorcinol (1.7 g), and anhydrous N,N-dimethylformamide (DMF, 15 mL) were then added into a two-neck vessel.…”
A NIR dye-coated silver nanoparticle/carbon dot nano-composite (CyOH–AgNP/CD) was synthetized as a novel nanophotosensitizer for targeted tumor imaging and high-efficiency PDT. The CyOH–AgNP/CD exhibit potential for future clinical imaging-guided PDT.
“…After 3 and 7 days, cells on different GO and RGO substrates were collected and incubated with BioTracker™ CyP AP dye (10 μM) (Millipore) in MEM medium for 30 min at 37 °C followed by PBS washing. 47 Cellular ALP activity catalyzes cleavage of the phosphate group in CyP, emitting fluorescence in the near-infrared spectrum, which was quantified using laser scanning microscopy (LSM 510) with an excitation wavelength at 635 nm and emission wavelength at 680−780 nm in the spectral detector.…”
Section: Alkaline Phosphatase (Alp) Activity and Differentiationmentioning
The use of graphene-based materials (GBMs) for tissue-engineering applications is growing exponentially due to the seemingly endless multi-functional and tunable physicochemical properties of graphene, which can be exploited to influence cellular behaviours. Despite many demonstrations wherein cell physiology can be modulated on GBMs, a clear mechanism connecting the different physicochemical properties of different GBMs to cell fate has remained elusive. In this work, we demonstrate how different GBMs can be used to cell fate in a multi-scale studystarting from serum protein (Fibronectin) adsorption to molecular scale morphology, structure and bioactivity, and finally ending with stem cell response. By changing the surface chemistry of graphene substrates with only heating, we show that molecular conformation and morphology of surface adsorbed fibronectin controls epitope presentation, integrin binding, and stem cell attachment. Moreover, this subtle change in protein structure is found to drive increased bone differentiation of cells, suggesting that physicochemical properties of graphene substrates exert cell control by influencing adsorbed protein structure.Keywords: Graphene-based materials (GBMs), protein interaction, protein molecular structure, protein bioactivity, stem cell differentiation, identification of biochemical activity changes of insulin on graphene and GO surfaces was presented. Experiments directly probing protein molecular structure, conformation, and exposure of bioactive domains of proteins are required to unequivocally demonstrate if GBMs modulate protein structure to influence stem cell interaction. In addition, controlled experiments evaluating the effect of the adsorbed protein and its molecular features on stem cell attachment and differentiation should be done in absence and presence of serum. Providing such experiments will provide mechanistic insight on GBM-mediated stem cell response for future rational design of materials from graphene.Here, we study ECM protein adsorption, interaction, orientation and structure from the macroscale to the molecular scale on GBMs and perform stem cell culture in the presence and absence of serum to relate the physicochemistry of GBMs with protein structure and cell fate. We used GO and RGOthe two most commonly used GBMs as exemplary engineering materialsto evaluate bioactivity of GBMs having different surface chemistries by investigating the effect of GBM chemistry on fibronectin (FNa protein abundant in the ECM), adsorption, orientation, and structure. We couple these surface characterization experiments with biochemical activity assays and stem cell response experiments, allowing us to elucidate the link between physicochemical properties of GBMs, FN protein unfolding, altered biochemical activity, and stem cell differentiation.Corresponding Authors
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