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LuxeSci Show Notes: S1E12: Platinum

Hello again.  Welcome back to LuxeSci - a podcast to re-ignite your wonder by exploring the science behind luxury items.  I’m Dr Lex, PhD, infectious disease expert and jewelry lover.  I’m joined by my co-host Dr. Dimos, also a PhD, electrical engineer and materials science enthusiast.

So we’re continuing our theme of materials used in fine jewelry with platinum. I think the first time I saw platinum was my grandmothers wedding ring set.  It wasn’t super fancy but it was out of platinum and it does have a different sheen to it than silver.  

Dimos - what’s your experience been with platinum?

So here’s a microbiologists and electrical engineer’s take on the science of platinum. 

Background (Alexis)

  • Atomic symbol - Pt

  • Atomic number - 78 (very close to silver)

  • Dense, malleable, ductile, highly unreactive

  • One of the least reactive metals

  • Silverish-white transition metal

  • Name originate from the Spanish platina a diminutive of plata (silver)

  • It has six naturally occurring isotopes (isotope = atoms that have the same number of protons (so same atomic number) but different numbers of neutrons)

  • Rare earth element - average abundance of 5ug/kg - only a few hundred tonnes produced a year

  • South Africa accounts for 80% of the world production of platinum

  • Found in nickel and copper ores 

  • History - archeaologists have found platinum in the gold used in ancient Egyptian burials. Although they think that it was accidental contamination as opposed to the Egyptians consciously using the platinum

  • pre-Columbian Americans in Ecuador used platinum-white gold alloys to produce artifacts

  • The tradition of platinum-working is usually traces to South American and the La Tolita Culture (around 600BC - AD 200) but precise dates and locations are hard to pinpoint. 

  • They would combine gold and platinum and the resulting alloy would be soft enough to shape with tools

  • The first European reference to platinum is in the 1557 writings of an Italian humarist describing an unknown nobel metal found between Darien and Mexico.

  • In the 1700s, there was a more scientific study of platinum by various chemists who presented their findings in papers describing the metal and in 1786 Charles III of Spain provided a library and laboratory to Pierre-Francois Chabaneau to research platinum. Chabaneau succeed in producing 23 kilograms of pure, malleable platinum and started a business, ushering the ‘platinum age’ in Spain.

  • Platinum has a variety of uses and is found in catalytic converters, laboratory equipment, electrical contacts and electrodes, dentistry equipment and of course, jewelery

  • Platinum is also used in the glass industry to manipulate molten glass

  • Platinum’s popularity in jewelry is due to both it’s strength and durability but also its prestige since it’s so rare

  • Does get scratched and dull so requires cleaning and polishing every few years


  • I’m going to talk about the anti-tumor properties of platinum and the chemotherapeutics that have sprung from that

  • Chemotherapeutic - chemical entities used to treat or cure cancer

  • BH Rosenberg and team discovered the anti-tumor properties of platinum (or ate least were the first ones to publish on it) in a paper entitled Platinum Compounds: A New Class of Potent Antitumor Agents in Nature Cell Bio in 1969

  • The team subsequently published in the journal Naturwissenschaften in 1973 (love that journal name)

  • I’m going to dip into my well of review articles to start of this discussion.  Giuliano Ciarimboli published a great review of platinum chemotherapeutics in the journal Biomolecules in 2021 and that’s where we’ll start

  • Cisplatin - the first platinum drug was approved by the FDA in 1978 for the treatment of testicular cancer, advanced ovarian cancer and bladder cancer.

  • Still used in combination therapy for solid tumors (ie. bladder, cervical, ovarian, lung, gastric, breast and head and neck cancers)

  • Was considered almost curative for treatment of testicular cancer

  • Nearly half of all chemotherapeutic protocols for cancer contain platinum derivatives

  • Mechanisms of action

  • Platinum binds to the DNA of the cancer cells (much like silver can bind bacterial DNA from our last episode) and produces distortions of the double helix

  • This impacts DAN transcription and replication and induces cell apoptosis

  • Cancer cell by definition cannot properly repair DNA and so are more sensitive to the effects of platinum

  • Platinum also binds to other cellular components and modulates the activity of the immune system

  • In a review by Cedric Rebe et al, they discuss immunogenic cancer cell death. This is when the cancer cell changes the composition of the cell surface and also releases molecules (this happens in a defined sequence).  These signals then active receptors expressed by dendritic cells and stimulate them to present the tumor antigens to T cells.  So essentially the cancer cell makes itself more visible to the immune system.

  • Platinum cancer drugs are particularly good at inducing ICD and this can lead to the eradication of cancer cells (with oxaliplatin being the best drug)

  • Unfortunately, cancers can develop resistance to platinum-based drugs and the drugs come with severe side effects, including nephrotoxicity (kidney toxicity), obtotoxicity (developmet of hearing or balance problems), myelosuppression (reduction in bone marrow activity resulting in fewer red blood cells, white blood cells and platelets) and peripheral neurotoxicity.  These side effects mean that the doses of platinum drugs are limited and present severe quality of life challenges for patients

  • On paper by Frenzel et all published in Biomolecules focused on why people get these side effects from platinum-based drugs and found that the human organic cation transporters 2 (mediates the uptake of platinum drugs in various tissues) plays an important role in the side effects of the drugs. In fact, children who have a mutation in their hOCT2 gene are less prone to developing ototoxicity after therapy with cisplatin

  • To combat resistance to platinum drugs, researchers are looking at other platinum derivatives and looking at different delivery strategies.

  • Much like silver, platinum can be delivered via nanoparticle to better target just the cancer cells

  • One group of authors found that nanoporous silica could be used as nanocontainers for cisplatin drug delivery.

  • One delivery method that i found fascinating is photoactivation

  • Ziwen Dai and Zhigang Wang published in Molecules in 2020

  • Several different strategies including, photoreduction, photo-uncaging and photodissociation

  • Photoreduction - chemical reduction under the influence of radiant energy shift a spontaneous cellular reduction of the platinum complex to be a photo-induced reduction. These are activated by radiation

  • Photo-uncaging - revealing the active region of a compound by photolysis of a shielding molecule (requires appropriate wavelength, intensity and timing of the light)

  • Photodissociation - chemical compound is broken down by photons

  • Basically it’s designing the platinum drugs so that they can only be activated when in the tumor cells

  • Or course I have to mention antimicrobials.  Platinum-doped silver nanoparticles are being explored as a way to enhance silver ion release and lead to more antimicrobial activity.

  • Finally - we can’t ignore the environmental impact of platinum.  The mining of platinum not-withstanding, a 2019 article by Jasmina Rinkovec discusses the measurable quantities of platinum, palladium and rhodium airborne particulates due to the metals’ use in catalytic converters. The concentration of these metals has increased over the past 20 years but the health implications are still debated. Just one more thing to worry about with car emissions.  Dimos - do electric cars have catalytic converters?


  • Isotope - atoms that have the same number of protons (so same atomic number) but different numbers of neutrons

  • Chemotherapeutic - chemical entities used to treat or cure cance

  • Photoreduction - chemical reduction under the influence of radiant energy shift

  • Photo - uncaging - revealing the active region of a compound by photolysis of a shielding molecule

  • Photodissociation - chemical compound is broken down by photons

Fun cocktail party facts quiz

  • What language is the word platinum from (spanish)

  • Where does most of the world’s platinum come from (RSA)

I hope you’ve enjoyed exploring platinum with me and Dimos and I hope you remember a little fact from this episode the next time you see (or wear) platinum.  Thanks for listening to this episode of LuxeSci.  A very special thank you to my audio engineer and co-host, Dimos.  Our theme music is Harlequin Moon by Burdy. We’re on Twitter and Instagram at luxescipod.  Please subscribe and review where ever you listen. This episode we ask that you find that one super fashionable friend and share our podcast with them.



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