Nano
Tue Feb 19, 2019 10:56
Magnetic Nanoparticles Once Inside Cells
TEHRAN (FNA)- Although magnetic nanoparticles are being used more and more in cell imaging and tissue bioengineering, what happens to them within stem cells in the long term remained undocumented. Researchers have shown substantial degradation of these nanoparticles, followed in certain cases by the cells ''re-magnetizing.'' This phenomenon is the sign of biosynthesis of new magnetic nanoparticles from iron released in the intracellular medium by the degradation of the first nanoparticles.

Although magnetic nanoparticles are being used more and more in cell imaging and tissue bioengineering, what happens to them within stem cells in the long term remained undocumented. Researchers from CNRS, the Sorbonne Université, and universities Paris Diderot and Paris 13, have shown substantial degradation of these nanoparticles, followed in certain cases by the cells "re-magnetizing." This phenomenon is the sign of biosynthesis of new magnetic nanoparticles from iron released in the intracellular medium by the degradation of the first nanoparticles. Published in PNAS on February 11, 2019, this work may explain the presence of "natural" magnetism in human cells, and help us to envisage new tools for nanomedicine, thanks to this magnetism produced by the cells themselves.

Magnetic nanoparticles are at the core of today's nanomedicine: they serve as imaging diagnosis agents, thermal anti-cancer agents, drug targeting agents, and tissue engineering agents. The question of their fate in cells, after they have accomplished their therapeutic mission, was not well understood.

To follow the journey of these nanoparticles in cells, researchers at the Laboratoire Matière et Systèmes Complexes (CNRS/Université Paris Diderot) and the Laboratoire de Recherche Vasculaire Translationnelle (INSERM/Université Paris Diderot/Université Paris 13), in collaboration with scientists from Sorbonne Université[1] have developed an original approach to nanomagnetism in living systems: first they incorporated magnetic nanoparticles in vitro in human stem cells. They then left them to differentiate and develop for one month, to observe them long term in the intracellular environment and to monitor their transformations.

By following the "magnetic fingerprint" of these nanoparticles in the cells, the researchers have shown that they were first being destroyed (cell magnetization falls) and releasing iron into the intracellular environment. Next, this "free" iron was stored in non-magnetic form in ferritin, the protein responsible for storing iron, or served as a base for the biosynthesis of new magnetic nanoparticles within the cell.

This phenomenon is known to occur in some bacteria, but a biosynthesis like this had never been shown in mammalian cells. This could explain the presence of magnetic crystals in humans, observed in the cells of diverse organs, particularly the brain. What is more, this iron storage in magnetic form could also be a way for the cell to "detoxify" over the long term to counter excess iron. From the point of view of nanomedicine, this biosynthesis open up a new path to the possibility of purely biological magnetic marking in cells.

[1] 1 In collaboration with researchers at the Laboratoire Physicochimie des Electrolytes et Nanosystèmes Interfaciaux (CNRS/Sorbonne Université), IMPMC (CNRS/Sorbonne Université/MNHN/IRD), the Laboratoire Interfaces, Traitements, Organisation et Dynamique des Systèmes (CNRS/Université Paris Diderot).

 

 

 

Bottom top
Report: US Ice Officers 'Used Torture to Make Africans Sign Own Deportation Orders'

TEHRAN (FNA)- US immigration officers allegedly tortured Cameroonian asylum seekers to force them to sign their own deportation orders, in what lawyers and activists describe as a brutal scramble to fly African migrants out of the country in the run-up to the elections.
Iran Reports over 5,000 New Coronavirus Patients

TEHRAN (FNA)- The Iranian health ministry announced on Thursday 5,471 new cases of coronavirus infection have been reported across the country during the past 24 hours, adding that a total number of 550,757 patients have been identified since the first case was identified last February.
Poll: Biden's National Lead Narrows to 4 Points

TEHRAN (FNA)- Democratic nominee Joe Biden's lead over President Donald Trump narrowed to 4 percentage points in a new Hill-HarrisX national poll.
White House Leans on Pentagon to Fulfill Trump’s Afghanistan Pledge

TEHRAN (FNA)- The White House is turning up the pressure on the Pentagon to carry out President Donald Trump’s directive of a further withdrawal of US troops from Afghanistan, as the commander in chief looks to deliver on a campaign pledge ahead of next month’s election.
Two Women Stabbed at Eiffel Tower in Apparent Racist Attack

TEHRAN (FNA)- French police launched an investigation after two women were stabbed near the Eiffel Tower in an apparent racist incident.
Kremlin Rejects All US Election Meddling Accusations Against Russia

TEHRAN (FNA)- All accusations against Russia of trying to meddle in the electoral processes in the United States are totally unfounded, Kremlin Spokesman Dmitry Peskov told reporters on Thursday.
Iran's Indigenized Phased-Array Radars Trace Hypothetical Enemy Flying Targets in Wargames

TEHRAN (FNA)- The Iranian Army and the Islamic Revolution Guards Corps (IRGC)'s home-made phased-array radar systems detected and traced aggressive hostile flying objects during their joint aerial drills on Thursday.
Greece, Egypt, Cyprus Jointly Condemn Turkey’s ‘Aggression’ in Eastern Mediterranean

TEHRAN (FNA)- Turkey’s natural gas exploration and military activities in the disputed waters of the Eastern Mediterranean have been roundly condemned by its neighbors, who also criticized the recent reopening of a beach area in North Cyprus.
Сoronavirus Situation in Germany 'Has Become Very Serious', as Berlin Declares 4 European States 'Risk Regions'

TEHRAN (FNA)- Germany is facing a "very serious" rise in COVID-19 cases, but it is still possible to slow the spread of infection, the public health institute announced, as Berlin has issued new travel warnings for four European states.
Beijing Calls on US to Cancel Arms Sale to Taiwan

TEHRAN (FNA)- In response to the latest round of US arms sales to Taiwan, the Chinese Foreign Ministry called on Washington to cancel the proposed deal on Thursday.
Swiss Envoy to Iran Summoned over US Officials' Election Allegations

TEHRAN (FNA)- The Iranian foreign ministry on Thursday summoned the Swiss ambassador to Tehran, whose country represents the US interests in Iran, over the baseless allegations raised by the American officials.
Iran's Strategic Bavar 373 Missile Shield Intercepts Electro-Optic-Guided Target in Drills

TEHRAN (FNA)- Iran's home-made strategic missile defense system Bavar 373 could successfully intercept and destroy an electro-optic-guided target during the wargames codenamed 'Modafe'an-e Aseman-e Velayat 99' (Guardians of Velayat's Sky-99) being jointly staged by the Iranian Army and the Islamic Revolution Guards Corps (IRGC).
Iran to Hold Eurasia Economic Conference to Display Ineffectiveness of US Sanctions

TEHRAN (FNA)- Iran is due to host Eurasian Economic Union (EAEU)’s upcoming meeting in November to prove ineffectiveness of the US sanctions by cooperation with the regional states.
Iran Rejects Interference in US Elections

TEHRAN (FNA)- Spokesman for Iran’s mission to the United Nations in New York Alireza Miryousefi dismissed allegations of meddling in the US presidential elections.
Iranian Speaker's Advisor Expects Future of Region without Israel, US

TEHRAN (FNA)- Iranian Parliament Speaker's Special Aide for International Affairs Hossein Amir Abdollahian said that the future of the region will be built without the presence of Israel and the US.