HBI-002

Leonardo da Vinci is renowned to this day for innovations in fields across the arts and sciences. Now, new analyses show that his taste for experimentation extended even to the base layers underneath his paintings. Surprisingly, samples from both the 'Mona Lisa' and the 'Last Supper' suggest that he experimented with lead(II) oxide, causing a rare compound called plumbonacrite to form below his artworks. Leonardo da Vinci is renowned to this day for innovations in fields across the arts and sciences. Now, new analyses published in the Journal of the American Chemical Society show that his taste for experimentation extended even to the base layers underneath his paintings. Surprisingly, samples from both the "Mona Lisa" and the "Last Supper" suggest that he experimented with lead(II) oxide, causing a rare compound called plumbonacrite to form below his artworks. An aura of mystery has surrounded the paints and pigments in da Vinci's studio, leading scientists to scour his writings and artwork to search for clues. Many paintings from the early 1500s, including the "Mona Lisa," were painted on wooden panels that required a thick, "ground layer" of paint to be laid down before artwork was added. Scientists have found that while other artists typically used gesso, da Vinci experimented by laying down thick layers of lead white pigment and by infusing his oil with lead(II) oxide, an orange pigment that conferred specific drying properties to the paint above. He used a similar technique on the wall underneath the "Last Supper" -- a departure from the traditional, fresco technique used at the time. To further investigate these unique layers, Victor Gonzalez and colleagues wanted to apply updated, high-resolution analytical techniques to small samples from these two paintings. The team performed their analyses on a tiny, "microsample" previously obtained from a hidden corner of the "Mona Lisa," as well as 17 microsamples obtained from across the surface of the "Last Supper." Using X-ray diffraction and infrared spectroscopy techniques, they determined that the ground layers of these artworks not only contained oil and lead white, but also a much rarer lead compound: plumbonacrite (Pb5(CO3)O(OH)2). This material had not previously been detected in Italian Renaissance paintings, though it'd been found in later paintings by Rembrandt in the 1600s. Plumbonacrite is only stable under alkaline conditions, suggesting that it formed from a reaction between the oil and lead(II) oxide (PbO). Intact grains of PbO were also found in most of the samples taken from the "Last Supper." While painters were known to add lead oxides to pigments to help them dry, the technique has not been proved experimentally for paintings from da Vinci's time. In fact, when the researchers searched through his writings, the only evidence they found of PbO was in reference to skin and hair remedies, even though it's now known to be quite toxic. Though he might not have written it down, these results demonstrate that lead oxides must have had a place on the old master's palette, and might have helped create the masterpieces we know today.

SAN DIEGO, Sept. 20, 2023 /PRNewswire/ -- Hillhurst Biopharmaceuticals, Inc. ("Hillhurst"), a clinical-stage biopharmaceutical company focused on developing liquid drug products containing therapeutic gases, today announced the award of an approximately $3 million Phase 2b SBIR grant from the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health. This award, along with matching funds, will fund the company through a Phase 2a clinical study of HBI-002, an oral low dose carbon monoxide therapeutic candidate in patients with sickle cell disease (SCD). HBI-002 is targeted for the treatment of SCD. Hillhurst anticipates initiating this study in Q1 2024. "With this award, the NHLBI enables advancing HBI-002 into a population of individuals with sickle cell disease with the objective of addressing a significant unmet need," said Andrew Gomperts, Hillhurst's Chief Executive Officer. "We believe our novel approach of targeting dual mechanisms to prevent vaso-occlusive crises, including reducing both sickling and inflammation, holds great promise." About Sickle Cell Disease Sickle cell disease is a genetic disorder that causes severe vaso-occlusive pain crises and is associated with serious clinical consequences including stroke, heart disease, and kidney disease as well as premature death. The average life expectancy of SCD patients in the US is only 45 years, reflecting the substantial unmet medical need. About HBI-002 Hillhurst's lead product, HBI-002, is an oral drug product candidate of low dose CO, with an administration route designed to enable chronic use in a home setting for patients suffering from sickle cell disease. Other potential disease targets are conditions associated with inflammation and cell death such as Parkinson's disease. A Phase 1 clinical study with HBI-002 in healthy subjects under IND has been successfully completed. About Hillhurst Hillhurst is a clinical stage company focused on its proprietary GLASS™ platform, which enables novel drug products based on therapeutic gases that, up until now, have been limited by inhaled delivery, including a unique pipeline of novel liquid therapeutic candidates intended to treat patients with sickle cell disease, Parkinson's disease, and acute pain. This research is supported by the NHLBI under grant number 2R44HL131065-05, and its content is solely the responsibility of the authors and does not necessarily represent the official views of NIH. To learn more about Hillhurst, please visit .