Tag Archives: kidneys

Trick your kidneys with sugar (molecules, that is)

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A February 4, 2020 news item on Nanowerk announces research that makes it possible for kidneys to remove nanoparticles after they’ve been used in therapeutic remedies (Note: A link has been removed),

In the past decade nanomedicine has contributed to better detection and treatment of cancer. Nanoparticles are several 100 times smaller than the smallest grain of sand and can therefore easily travel in the blood stream to reach the tumor.

However, they are still too big to be removed by the kidneys. Since several doses of nanoparticles are necessary to treat a tumor, over time the nanoparticles can accumulate in the kidney and cause irreversible damage.

In a study published in the scientific journal Biomaterials (“Renal clearance of polymeric nanoparticles by mimicry of glycan surface of Viruses”), materials scientists at the University of Freiburg [Germany] led by Prof. Dr. Prasad Shastri from the Institute of Macromolecular Chemistry now present a natural solution to this problem: they built nanoparticles with the carbohydrate polysaccharides, which led to the excretion of the particles.

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A February 4, 2020 University of Freiberg press release (also on EurekAlert), which originated the news item, expands on the theme,

In nature viruses such as the herpes simplex virus-1 and the cytomegalovirus, which are able to pass through the kidney filtration apparatus despite their large size compared to nanoparticles. Shastri and his team identified that both viruses presents sugar molecules on their surface. Inspired by this observation, the scientists engineered nanoparticles containing polysaccharides. These carbohydrates are frequently found in the human tissue environment. Using a real-time imaging technique, which they have established in their laboratory, the team investigated in a mouse model the fate of these nanoparticles. They observed that the polysaccharide-enriched nanoparticles readily pass through the kidney and are excreted with the urine within a few hours after intravenous administration. The decisive factor for the researchers was that the nanoparticles continued to act as intended and were still able to target tumors.

“The ability to combine tumor accumulation and kidney clearance in the same nanoparticle represents a tipping point in ensuring that nanomedicines can be safely administered” says Shastri. “Our nature-inspired approach enabled us to trick the kidney environment to let nanoparticles pass through” adds Dr. Melika Sarem who was a co-author of the study.

Prasad Shastri is Professor of Biofunctional Macromolecular Chemistry at the Institute for Macromolecular Chemistry and Professor of Cell Signalling Environments in the Excellence Cluster BIOSS Centre for Biological Signalling Studies and at the University of Freiburg.

Here’s a link to and a citation for the paper,

Renal clearance of polymeric nanoparticles by mimicry of glycan surface of viruses by Pradeep P.Wyss, Surya P.Lamichhane, Ahmed Abed, Daniel Vonwil, Oliver Kretz, Tobias B. Huber, Melika Sarema, V. Prasad Shastri. Biomaterials Volume 230, February 2020, 119643 DOI: https://doi.org/10.1016/j.biomaterials.2019.119643 First published online November 23, 2019

This paper is behind a paywall.

From monitoring glucose in kidneys to climate change in trees

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That headline is almost poetic but I admit It’s a bit of a stretch rhymewise, kidneys/trees. In any event, a Feb. 6, 2015 news item on Azonano describes research into monitoring the effects of climate change on trees,

Serving as a testament to the far-reaching impact of Governor Andrew M. Cuomo’s commitment to maintaining New York State’s global leadership in nanotechnology innovation, SUNY Polytechnic Institute’s Colleges of Nanoscale Science and Engineering (SUNY Poly CNSE) today announced the National Science Foundation (NSF) has awarded $837,000 to support development of a first of its kind nanoscale sensor to monitor the effects of climate change on trees.

A Feb. 5, 2015 SUNY Poly CNSE news release, which originated the news item, provides more details including information about the sensor’s link to measuring glucose in kidneys,

The NSF grant was generated through the Instrument Development for Biological Research (IDBR) program, which provides funds to develop new classes of devices for bio-related research. The NANAPHID, a novel aphid-like nanosensor, will provide real-time measurements of carbohydrates in live plant tissue. Carbohydrate levels in trees are directly connected to plant productivity, such as maple sap production and survival. The NANAPHID will enable researchers to determine the effects of a variety of environmental changes including temperature, precipitation, carbon dioxide, soil acidity, pests and pathogens. The nanosensor can also provide real-time monitoring of sugar concentration levels, which are of signficant importance in maple syrup production and apple and grape farming.

“The technology for the NANAPHID is rooted in a nanoscale sensor SUNY Poly CNSE developed to monitor glucose levels in human kidneys being prepared for transplant. Our team determined that certain adjustments would enable the sensor to provide similar monitoring for plants, and provide a critical insight to the effects of climate change on the environment,” said Dr. James Castracane, professor and head of the Nanobioscience Constellation at SUNY Polytechnic Institute. “This is a perfect example of the cycle of innovation made possible through the ongoing nanotechnology research and development at SUNY Poly CNSE’s NanoTech Complex.”

“This new sensor will be used in several field experiments on measuring sensitivity of boreal forest to climate warming. Questions about forest response to rising air and soil temperatures are extremely important for forecasting future atmospheric carbon dioxide levels, climate change and forest health,” said Dr. Andrei Lapenas, principal investigator and associate professor of climatology at the University at Albany. “At the same time, we already see some potential commercial application for NANAPHID-type sensors in agriculture, food industry and other fields. Our collaboration with SUNY Poly CNSE has been extremely productive and I look forward to continuing our work together.”

The NANAPHID project began in 2014 with a $135,000 SUNY Research Foundation Network of Excellence grant. SUNY Poly CNSE will receive $400,000 of the NSF award for the manufacturing aspects of the sensor array development and testing. The remaining funds will be shared between Dr. Lapenas and researchers Dr. Ruth Yanai (ESF), Dr. Thomas Horton (ESF), and Dr. Pamela Templer (Boston University) for data collection and analysis.

“With current technology, analyzing carbohydrates in plant tissues requires hours in the lab or more than $100 a sample if you want to send them out. And you can’t sample the same tissue twice, the sample is destroyed in the analysis,” said Dr. Yanai. “The implantable device will be cheap to produce and will provide continuous monitoring of sugar concentrations, which is orders of magnitude better in both cost and in the information provided. Research questions we never dreamed of asking before will become possible, like tracking changes in photosynthate over the course of a day or along the stem of a plant, because it’s a nondestructive assay.”

“I see incredible promise for the NANAPHID device in plant ecology. We can use the sensors at the root tip where plants give sugars to symbiotic fungi in exchange for soil nutrients,” said Dr. Horton. “Some fungi are believed to be significant carbon sinks because they produce extensive fungal networks in soils and we can use the sensors to compare the allocation of photosynthate to roots colonized by these fungi versus the allocation to less carbon demanding fungi. Further, the vast majority of these symbiotic fungi cannot be cultured in lab. These sensors will provide valuable insights into plant-microbe interactions under field conditions.”

“The creation of this new sensor will make understanding the effects of a variety of environmental changes, including climate change, on the health and productivity of forests much easier to measure,” said Dr. Templer. “For the first time, we will be able to measure concentrations of carbohydrates in living trees continuously and in real-time, expanding our ability to examine controls on photosynthesis, sap flow, carbon sequestration and other processes in forest ecosystems.”

Fascinating, eh? I wonder who made the connection between human kidneys and plants and how that person made the connection.

Smart nanofibers could make kidney dialysis machines obsolete

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Kidney dialysis machines may become obsolete with the development of a specialized composite. From a March 4, 2014 news item on Nanowerk,

A simple way to treat kidney failure. A new technique for purifying blood using a nanofiber mesh could prove useful as a cheap, wearable alternative to kidney dialysis.

Kidney failure results in a build up of toxins and excess waste in the body. Dialysis is the most common treatment, performed daily either at home or in hospital. However, dialysis machines require electricity and careful maintenance, and are therefore more readily available in developed countries than poorer nations. Around one million people die each year worldwide from potentially preventable end-stage renal disease.

In addition to this, in the aftermath of disasters such as the Japanese earthquake and tsunami of 2011, dialysis patients are frequently left without treatment until normal hospital services are resumed. …

The March 4, 2014 International Center for Materials Nanoarchitectonics (MANA) research highlight, which originated the news item, describes the work in detail,

… Mitsuhiro Ebara and co-workers at the International Center for Materials Nanoarchitectonics, National Institute for Materials Science in Ibaraki, Japan, have developed a way of removing toxins and waste from blood using a cheap, easy-to-produce nanofiber mesh1. The mesh could be incorporated into a blood purification product small enough to be worn on a patient’s arm, reducing the need for expensive, time-consuming dialysis.

The team made their nanofiber mesh using two components: a blood-compatible primary matrix polymer made from polyethylene-co-vinyl alchohol, or EVOH, and several different forms of zeolites – naturally occurring aluminosilicates. Zeolites have microporous structures capable of adsorbing toxins such as creatinine from blood.

The researchers generated the mesh using a versatile and cost-effective process called electrospinning – using an electrical charge to draw fibers from a liquid. Ebara and his team found that the silicon-aluminum ratio within the zeolites is critical to creatinine adsorption. Beta type 940-HOA zeolite had the highest capacity for toxin adsorption, and shows potential for a final blood purification product.
Although the new design is still in its early stages and not yet ready for production, Ebara and his team are confident that a product based on their nanofiber mesh will soon be a feasible, compact and cheap alternative to dialysis for kidney failure patients across the world.

The word “soon” may not mean the same thing to the research team as it does to a patient using kidney dialysis machines and, unfortunately, the researchers don’t offer specifics as to when this mesh might be available.

Here’s a link to and a citation for the researchers’ paper,

Fabrication of zeolite–polymer composite nanofibers for removal of uremic toxins from kidney failure patients by Koki Namekawa, Makoto Tokoro Schreiber, Takao Aoyagi and Mitsuhiro Ebara.  Biomater. Sci., 2014, Advance Article DOI: 10.1039/C3BM60263J First published online 31 Jan 2014

It is an open access paper although you will need to ‘log in’ in some fashion.