scholarly journals Luminescent gold nanoclusters for bioimaging applications

2020 ◽  
Vol 11 ◽  
pp. 533-546 ◽  
Author(s):  
Nonappa

Luminescent nanomaterials have emerged as attractive candidates for sensing, catalysis and bioimaging applications in recent years. For practical use in bioimaging, nanomaterials with high photoluminescence, quantum yield, photostability and large Stokes shifts are needed. While offering high photoluminescence and quantum yield, semiconductor quantum dots suffer from toxicity and are susceptible to oxidation. In this context, atomically precise gold nanoclusters protected by thiol monolayers have emerged as a new class of luminescent nanomaterials. Low toxicity, bioavailability, photostability as well as tunable size, composition, and optoelectronic properties make them suitable for bioimaging and biosensing applications. In this review, an overview of the sensing of pathogens, and of in vitro and in vivo bioimaging using luminescent gold nanoclusters along with the limitations with selected examples are discussed.

2020 ◽  
Author(s):  
Ozgun Kocabiyik ◽  
Valeria Cagno ◽  
Paulo Jacob Silva ◽  
Yong Zhu ◽  
Laura Sedano ◽  
...  

AbstractInfluenza is one of the most widespread viral infections worldwide and represents a major public health problem. The risk that one of the next pandemics is caused by an influenza strain is very high. It is very important to develop broad-spectrum influenza antivirals to be ready for any possible vaccine shortcomings. Anti-influenza drugs are available but they are far from ideal. Arguably, an ideal antiviral should target conserved viral domains and be virucidal, i.e. irreversibly inhibit viral infectivity. Here, we describe a new class of broad-spectrum anti-influenza macromolecules that meets these criteria and displays exceedingly low toxicity. These compounds are based on a cyclodextrin core modified on its primary face with long hydrophobic linkers terminated in 6’sialyl-N-acetyllactosamine (6’SLN) or 3’SLN. SLN enables nanomolar inhibition of the viruses while the hydrophobic linkers confer irreversibility to the inhibition. The combination of these two properties allows for efficacy in vitro against several human or avian influenza strains, as well as against a 2009 pandemic influenza strain ex vivo. Importantly, we show that, in mice, the compounds provide therapeutic efficacy when administered 24h post-infection allowing 90% survival as opposed to no survival for the placebo and oseltamivir..


Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2693 ◽  
Author(s):  
Olívia Sampaio ◽  
Lucas Vieira ◽  
Barbara Bellete ◽  
Beatriz King-Diaz ◽  
Blas Lotina-Hennsen ◽  
...  

Eight alkaloids (1–8) were isolated from Ruta graveolens, and their herbicide activities were evaluated through in vitro, semivivo, and in vivo assays. The most relevant results were observed for Compounds 5 and 6–8 at 150 μM, which decreased dry biomass by 20% and 23%, respectively. These are significant results since they presented similar values with the positive control, commercial herbicide 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU). Based on the performed assays, Compound 5 (graveoline) is classified as an electron-transport inhibitor during the light phase of photosynthesis, as well as a plant-growth regulator. On the other hand, Compounds 6–8 inhibited electron and energy transfers, and are also plant-growth inhibitors. These phytotoxic behaviors based on acridone and quinolone alkaloids may serve as a valuable tool in the further development of a new class of herbicides since natural products represent an interesting alternative to replace commercial herbicides, potentially due their low toxicity.


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1066
Author(s):  
Joanna Sobska ◽  
Magdalena Waszkielewicz ◽  
Anna Podleśny-Drabiniok ◽  
Joanna Olesiak-Banska ◽  
Wojciech Krężel ◽  
...  

Gold nanoparticles hold a great promise for both clinical and preclinical applications. The major factors impeding such applications are toxicity of new nanomaterials including e.g., pro-apoptotic activities or inflammatory effects, but also their potential to accumulate in the body or inadequate absorption, distribution, metabolism and excretion (ADME) profiles. Since such adverse effects depend on the size, form and coating of nanomaterials, the search for new, less toxic nanomaterials with low tendency to accumulate is highly active domain of research. Here, we describe optical and biological properties of Au18 gold nanoclusters (NCs), small gold nanoparticles composed of 18 atoms of gold and stabilized with glutathione ligands. These nanoclusters may be suitable for in vivo applications owing to their low toxicity and biodistribution profile. Specifically, using lactate dehydrogenase (LDH) test in P19 cell line we found that Au18 NCs display low toxicity in vitro. Importantly, using primary microglial cells we showed that at low concentrations Au18 NCs display anti-inflammatory signaling on evidence of reduced interleukin 1-β (IL1-β) levels and unchanged levels of tumor necrosis factor (TNF-α) or Ym1/2. Such effect was dose dependent as higher concentrations of Au18 NCs induced expression of pro-inflammatory cytokines and suppression of anti-inflammatory cytokine Ym1/2, pointing, thus, to global inflammatory activity. Finally, we also showed that within 3 days Au18 NCs can be completely eliminated from the liver reported as the major target organ for accumulation of gold nanoparticles. These data point to a potential of gold nanoparticles for further biomedical studies.


Molecules ◽  
2019 ◽  
Vol 24 (20) ◽  
pp. 3800
Author(s):  
Elena Aguilera ◽  
Cintya Perdomo ◽  
Alejandra Espindola ◽  
Ileana Corvo ◽  
Paula Faral-Tello ◽  
...  

Chagas disease and Leishmaniasis are neglected endemic protozoan diseases recognized as public health problems by the World Health Organization. These diseases affect millions of people around the world however, efficient and low-cost treatments are not available. Different steroid molecules with antimicrobial and antiparasitic activity were isolated from diverse organisms (ticks, plants, fungi). These molecules have complex structures that make de novo synthesis extremely difficult. In this work, we designed new and simpler compounds with antiparasitic potential inspired in natural steroids and synthesized a series of nineteen steroidal arylideneketones and thiazolidenehydrazines. We explored their biological activity against Leishmania infantum, Leishmania amazonensis, and Trypanosoma cruzi in vitro and in vivo. We also assayed their genotoxicity and acute toxicity in vitro and in mice. The best compound, a steroidal thiosemicarbazone compound 8 (ID_1260) was active in vitro (IC50 200 nM) and in vivo (60% infection reduction at 50 mg/kg) in Leishmania and T. cruzi. It also has low toxicity in vitro and in vivo (LD50 >2000 mg/kg) and no genotoxic effects, being a promising compound for anti-trypanosomatid drug development.


2019 ◽  
Vol 26 (30) ◽  
pp. 5609-5624
Author(s):  
Dijana Saftić ◽  
Željka Ban ◽  
Josipa Matić ◽  
Lidija-Marija Tumirv ◽  
Ivo Piantanida

: Among the most intensively studied classes of small molecules (molecular weight < 650) in biomedical research are small molecules that non-covalently bind to DNA/RNA, and another intensively studied class is nucleobase derivatives. Both classes have been intensively elaborated in many books and reviews. However, conjugates consisting of DNA/RNA binder covalently linked to nucleobase are much less studied and have not been reviewed in the last two decades. Therefore, this review summarized reports on the design of classical DNA/RNA binder – nucleobase conjugates, as well as data about their interactions with various DNA or RNA targets, and even in some cases protein targets are involved. According to these data, the most important structural aspects of selective or even specific recognition between small molecule and target are proposed, and where possible related biochemical and biomedical aspects were discussed. The general conclusion is that this, rather new class of molecules showed an amazing set of recognition tools for numerous DNA or RNA targets in the last two decades, as well as few intriguing in vitro and in vivo selectivities. Several lead research lines show promising advancements toward either novel, highly selective markers or bioactive, potentially druggable molecules.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Lu Wang ◽  
Shuwei Liu ◽  
Chunxia Ren ◽  
Siyuan Xiang ◽  
Daowei Li ◽  
...  

AbstractNanomaterial-based drug sustainable release systems have been tentatively applied to bone regeneration. They, however, still face disadvantages of high toxicity, low biocompatibility, and low drug-load capacity. In view of the low toxicity and high biocompatibility of polymer nanomaterials and the excellent load capacity of hollow nanomaterials with high specific surface area, we evaluated the hollow polydopamine nanoparticles (HPDA NPs), in order to find an optimal system to effectively deliver the osteogenic drugs to improve treatment of bone defect. Data demonstrated that the HPDA NPs synthesized herein could efficiently load four types of osteogenic drugs and the drugs can effectively release from the HPDA NPs for a relatively longer time in vitro and in vivo with low toxicity and high biocompatibility. Results of qRT-PCR, ALP, and alizarin red S staining showed that drugs released from the HPDA NPs could promote osteogenic differentiation and proliferation of rat bone marrow mesenchymal stem cells (rBMSCs) in vitro. Image data from micro-CT and H&E staining showed that all four osteogenic drugs released from the HPDA NPs effectively promoted bone regeneration in the defect of tooth extraction fossa in vivo, especially tacrolimus. These results suggest that the HPDA NPs, the biodegradable hollow polymer nanoparticles with high drug load rate and sustainable release ability, have good prospect to treat the bone defect in future clinical practice.


The Analyst ◽  
2021 ◽  
Author(s):  
Subhajit Chakraborty ◽  
Atanu Nandy ◽  
Subhadip Ghosh ◽  
Nirmal Kumar Das ◽  
Sameena Parveen ◽  
...  

Sub-nanomolar selective detection of Hg(ii) ions by protein (Human Serum Albumin, HSA) templated gold nanoclusters (AuNCs), both in in vitro as well as in vivo environments and specific endocytose behaviour towards breast cancer (BC) cell lines.


Nanoscale ◽  
2021 ◽  
Author(s):  
Parinaz Fathi ◽  
Ayman Roslend ◽  
Kritika Mehta ◽  
Parikshit Moitra ◽  
Kai Zhang ◽  
...  

Increasing the fluorescence quantum yield of fluorophores is of great interest for in vitro and in vivo biomedical imaging applications. At the same time, photobleaching and photodegradation resulting from continuous...


Drug Research ◽  
2017 ◽  
Vol 68 (04) ◽  
pp. 205-212 ◽  
Author(s):  
Wanqing Li ◽  
Zhiguo Li ◽  
Lisha Wei ◽  
Aiping Zheng

AbstractWe created a novel paclitaxel (PTX) nanoparticle drug delivery system and compared this to acommercial injection preparation to evaluate the antitumor effects for both formulations in vivo and in vitro.PTXnanocrystals were 194.9 nm with potential of −29.6 mV. Cytotoxicity tests indicated that both formulations had similar effects and cytotoxicity was dose- and time-dependent.Pharmacodynamics indicated that the drug concentration at the tumor was greater with PTX nanocrystals compared to commercial injection (P<0.01) and that drug accumulated more and for a longer duration. In vivo antitumor evaluation indicated significant antitumor effects and low toxicity of PTX nanocrystals. Moreover, bioimaging indicated that the PTX retention time in MCF-7-bearing mice was longer, especially at the tumor site, and this high drug concentration was maintained for a long time.Overall, PTX nanocrystalsare feasible and superior to traditional injection formulation chemotherapy.


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