scholarly journals Carbon nano-dot for cancer studies as dual nano-sensor for imaging intracellular temperature or pH variation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Trilochan Gadly ◽  
Goutam Chakraborty ◽  
Mrityunjay Tyagi ◽  
Birija S. Patro ◽  
Bijaideep Dutta ◽  
...  

AbstractCellular temperature and pH govern many cellular physiologies, especially of cancer cells. Besides, attaining higher cellular temperature plays key role in therapeutic efficacy of hyperthermia treatment of cancer. This requires bio-compatible, non-toxic and sensitive probe with dual sensing ability to detect temperature and pH variations. In this regard, fluorescence based nano-sensors for cancer studies play an important role. Therefore, a facile green synthesis of orange carbon nano-dots (CND) with high quantum yield of 90% was achieved and its application as dual nano-sensor for imaging intracellular temperature and pH was explored. CND was synthesized from readily available, bio-compatible citric acid and rhodamine 6G hydrazide using solvent-free and simple heating technique requiring purification by dialysis. Although the particle size of 19 nm (which is quite large for CND) was observed yet CND exhibits no surface defects leading to decrease in photoluminescence (PL). On the contrary, very high fluorescence was observed along with good photo-stability. Temperature and pH dependent fluorescence studies show linearity in fluorescence intensity which was replicated in breast cancer cells. In addition, molecular nature of PL of CND was established using pH dependent fluorescence study. Together, the current investigation showed synthesis of highly fluorescent orange CND, which acts as a sensitive bio-imaging probe: an optical nano-thermal or nano-pH sensor for cancer-related studies.

2008 ◽  
Vol 183 (5) ◽  
pp. 865-879 ◽  
Author(s):  
Christian Frantz ◽  
Gabriela Barreiro ◽  
Laura Dominguez ◽  
Xiaoming Chen ◽  
Robert Eddy ◽  
...  

Newly generated actin free barbed ends at the front of motile cells provide sites for actin filament assembly driving membrane protrusion. Growth factors induce a rapid biphasic increase in actin free barbed ends, and we found both phases absent in fibroblasts lacking H+ efflux by the Na-H exchanger NHE1. The first phase is restored by expression of mutant cofilin-H133A but not unphosphorylated cofilin-S3A. Constant pH molecular dynamics simulations and nuclear magnetic resonance (NMR) reveal pH-sensitive structural changes in the cofilin C-terminal filamentous actin binding site dependent on His133. However, cofilin-H133A retains pH-sensitive changes in NMR spectra and severing activity in vitro, which suggests that it has a more complex behavior in cells. Cofilin activity is inhibited by phosphoinositide binding, and we found that phosphoinositide binding is pH-dependent for wild-type cofilin, with decreased binding at a higher pH. In contrast, phosphoinositide binding by cofilin-H133A is attenuated and pH insensitive. These data suggest a molecular mechanism whereby cofilin acts as a pH sensor to mediate a pH-dependent actin filament dynamics.


2018 ◽  
Vol 217 (11) ◽  
pp. 3965-3976 ◽  
Author(s):  
Katharine A. White ◽  
Bree K. Grillo-Hill ◽  
Mario Esquivel ◽  
Jobelle Peralta ◽  
Vivian N. Bui ◽  
...  

β-Catenin functions as an adherens junction protein for cell–cell adhesion and as a signaling protein. β-catenin function is dependent on its stability, which is regulated by protein–protein interactions that stabilize β-catenin or target it for proteasome-mediated degradation. In this study, we show that β-catenin stability is regulated by intracellular pH (pHi) dynamics, with decreased stability at higher pHi in both mammalian cells and Drosophila melanogaster. β-Catenin degradation requires phosphorylation of N-terminal residues for recognition by the E3 ligase β-TrCP. While β-catenin phosphorylation was pH independent, higher pHi induced increased β-TrCP binding and decreased β-catenin stability. An evolutionarily conserved histidine in β-catenin (found in the β-TrCP DSGIHS destruction motif) is required for pH-dependent binding to β-TrCP. Expressing a cancer-associated H36R–β-catenin mutant in the Drosophila eye was sufficient to induce Wnt signaling and produced pronounced tumors not seen with other oncogenic β-catenin alleles. We identify pHi dynamics as a previously unrecognized regulator of β-catenin stability, functioning in coincidence with phosphorylation.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1990
Author(s):  
Kai Zhang ◽  
Jingjing Li ◽  
Xiaofei Xin ◽  
Xiaoqing Du ◽  
Di Zhao ◽  
...  

The co-delivery of chemotherapeutic agents and immune modulators to their targets remains to be a great challenge for nanocarriers. Here, we developed a hybrid thermosensitive nanoparticle (TMNP) which could co-deliver paclitaxel-loaded transferrin (PTX@TF) and marimastat-loaded thermosensitive liposomes (MMST/LTSLs) for the dual targeting of cancer cells and the microenvironment. TMNPs could rapidly release the two payloads triggered by the hyperthermia treatment at the site of tumor. The released PTX@TF entered cancer cells via transferrin-receptor-mediated endocytosis and inhibited the survival of tumor cells. MMST was intelligently employed as an immunomodulator to improve immunotherapy by inhibiting matrix metalloproteinases to reduce chemokine degradation and recruit T cells. The TMNPs promoted the tumor infiltration of CD3+ T cells by 2-fold, including memory/effector CD8+ T cells (4.2-fold) and CD4+ (1.7-fold), but not regulatory T cells. Our in vivo anti-tumor experiment suggested that TMNPs possessed the highest tumor growth inhibitory rate (80.86%) compared with the control group. We demonstrated that the nanoplatform could effectively inhibit the growth of tumors and enhance T cell recruitment through the co-delivery of paclitaxel and marimastat, which could be a promising strategy for the combination of chemotherapy and immunotherapy for cancer treatment.


2020 ◽  
pp. 1-6
Author(s):  
Andras Szasz ◽  
Andras Szasz

Hyperthermia treatment for solid tumors is a long-used, but poorly accepted method in clinical use. Modulated electro-hyperthermia (mEHT, trade name: oncothermia®) changes the paradigm, introduces a novel, cellularly selective and immunogenic cell-ruination. The mEHT method produces tumor-vaccination, presenting the unharmed genetic information of cancer cells to immune cells [1]. The mEHT method is approved in more than 30 countries. Its phase II/III clinical applications indicate a broad perspective.


2019 ◽  
Vol 130 ◽  
pp. 997-1008 ◽  
Author(s):  
Arokia Vijaya Anand Mariadoss ◽  
Ramachandran Vinayagam ◽  
Vijayalakshmi Senthilkumar ◽  
Manickam Paulpandi ◽  
Kadarkarai Murugan ◽  
...  

2020 ◽  
Vol 4 (3) ◽  
pp. 941-949 ◽  
Author(s):  
Xinzhe Yang ◽  
Qian Wang ◽  
Peiyu Hu ◽  
Chao Xu ◽  
Wenjing Guo ◽  
...  

An ionic AIEgen with high fluorescence quantum yield shows remarkable and reversible mechanochromism as well as excellent mitochondrial imaging of cancer cells and long-term tracking of tumors.


2018 ◽  
Vol 42 (24) ◽  
pp. 19818-19826 ◽  
Author(s):  
Jayanta Mandal ◽  
Pravat Ghorai ◽  
Paula Brandão ◽  
Kunal Pal ◽  
Parimal Karmakar ◽  
...  

A simple, low cost aminoquinoline based pH sensor,HLwas prepared and it works at a low pH range.HLexhibits cell permeability and used as an effective tool for differentiating between normal and cancer cells.


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