Breaking News
March 19, 2019 - Researchers use big data to gain better understanding of hepatitis E virus
March 19, 2019 - Use of synthetic psychedelic linked to improvements in depression and anxiety
March 19, 2019 - Knee Pain Not Tied to Activity Levels in Knee Osteoarthritis
March 19, 2019 - Study shows benefits of delayed cord clamping in healthy babies
March 19, 2019 - A cell’s “self-destruct” function could yield new therapies
March 19, 2019 - Latest advances and perspectives of all AI types used in pharmaceutical R&D
March 19, 2019 - Prophylactic cranial irradiation used as standard approach for patients with NSCLC
March 19, 2019 - Sugar-sweetened beverages may be linked with increased risk of cardiovascular mortality
March 19, 2019 - AHA News: Black Woman in Their 50s Face Especially High Stroke Risk
March 19, 2019 - Secrets of early life revealed from less than half a teaspoon of blood
March 19, 2019 - Immune cells engineered to tattle on suspicious cells in the body
March 19, 2019 - Heart attack patients who are taken to heart care centres directly survive longer
March 19, 2019 - IVF babies have increased in birthweight over the past 25 years, study reveals
March 19, 2019 - Study highlights the need for psychiatric care to be integrated into cancer treatment
March 19, 2019 - Testosterone treatment lowers recurrence rates in low-risk prostate cancer patients
March 19, 2019 - Caterpillars could hold the secret to new treatment for Osteoarthritis
March 19, 2019 - Parkinson’s treatment delivers a power-up to brain cell ‘batteries’
March 19, 2019 - Stanford launches new Institute for Human-Centered Artificial Intelligence
March 19, 2019 - Wireless earphones may cause cancer
March 18, 2019 - ACC/AHA guideline for prevention of cardiovascular disease released
March 18, 2019 - UTA nursing professor receives $6.575 million to attack musculoskeletal diseases
March 18, 2019 - Gene medication shows promise to treat spinal cord injuries
March 18, 2019 - First Human Study of “Robotic” RaniPill™ Capsule to Replace Injections Announced by Rani Therapeutics
March 18, 2019 - Food Allergy Testing: MedlinePlus Lab Test Information
March 18, 2019 - Altered brain activity patterns of Parkinson’s captured in mice
March 18, 2019 - Apple Heart Study demonstrates ability of wearable technology to detect atrial fibrillation | News Center
March 18, 2019 - Cardiovascular benefits of diabetes drug extend across a wide spectrum of patients, shows study
March 18, 2019 - Novel cardiac pump shows superior outcomes in patients with advanced heart failure
March 18, 2019 - U.S. FDA Grants Priority Review for Fedratinib New Drug Application in Myelofibrosis
March 18, 2019 - Living like a caveman won’t make you thin—but it might make you healthy
March 18, 2019 - Modified immune cells issue alert when detecting cancer in mice | News Center
March 18, 2019 - Dementia caregivers design robots for alleviating stress and increasing joyful moments
March 18, 2019 - VR technology could help improve balance in humans
March 18, 2019 - Study demonstrates effective way to slow progression of cerebrovascular disease in older adults
March 18, 2019 - Premature babies also have protective anti-viral antibodies
March 18, 2019 - Painkillers taken by pregnant mothers unlikely to cause asthma in the child
March 18, 2019 - Fibromyalgia can be reliably detected in blood samples
March 18, 2019 - Marijuana use has dropped among most teens after legalization
March 18, 2019 - Legacy Pharmaceutical Packaging, LLC Issues Voluntary Nationwide Recall of Losartan Potassium Tablets, USP, 25mg, 50mg, And 100mg Due to The Detection of Trace Amounts Of N-Nitroso N-Methyl 4-Amino Butyric Acid (NMBA) Impurity Found in The Active Pharmaceutical Ingredient (API)
March 18, 2019 - Researchers identify early home and family factors that contribute to obesity
March 18, 2019 - Fate and festivity: Match Day 2019
March 18, 2019 - Study finds TAVR to be as good as open-heart surgery for patients at low surgical risk
March 18, 2019 - EU-funded project is developing new tools for diagnosing cancer
March 18, 2019 - Gluten, lactose, food dyes in pills could be causing side effects finds study
March 18, 2019 - Taking painkillers during pregnancy is not responsible for asthma risk in children, study shows
March 18, 2019 - Prediagnosis Psychiatric Care Linked to Worse Cancer Mortality
March 18, 2019 - Paris hospital halts stool study after donor deluge
March 18, 2019 - Partial oral antibiotic therapy shows efficacy and safety in patients with infectious endocarditis
March 18, 2019 - Olympus improves access to science education through BioBus collaboration
March 18, 2019 - Depression screening does not improve quality of life in heart attack patients
March 18, 2019 - Echocardiography may aid in patient selection for TMVR
March 18, 2019 - Are ‘Inactive’ Ingredients in Your Drugs Really So Harmless?
March 18, 2019 - Wearable technology can safely identify atrial fibrillation
March 18, 2019 - Scientists tackle rare retinal disease in unique research project
March 18, 2019 - Death By A Thousand Clicks
March 18, 2019 - Absorbable, antibiotic-eluting envelope can reduce rate of cardiac device infections
March 18, 2019 - Hormonal treatment associated with depression in men with prostate cancer
March 18, 2019 - Porvair Sciences launches reinforced 96-well deep round microplate
March 18, 2019 - Simplified catheter ablation could slash waiting lists for atrial fibrillation patients
March 18, 2019 - BFR therapy as part of rehabilitation following ACL surgery may slow bone loss
March 18, 2019 - A human model to test implants for cataract surgery
March 18, 2019 - New risk adjustment model could reduce financial penalty for safety net hospitals
March 18, 2019 - NHS cancer patients’ wait to start treatment worrying
March 18, 2019 - Inventiva Announces Results from Phase IIb Clinical Trial with Lanifibranor in Systemic Sclerosis
March 18, 2019 - Cologuard
March 18, 2019 - Researchers find evidence of prenatal environment tuning genomic imprinting
March 18, 2019 - Dolomite Bio launches novel Nadia product family for single-cell research
March 18, 2019 - Intellipharmaceutics Announces Resubmission of New Drug Application to the U.S. FDA for its Oxycodone ER
March 18, 2019 - Excessive gestational weight gain tied to maternal morbidity
March 18, 2019 - RCEM issues position statement on metrics to supplement four-hour standard target
March 17, 2019 - Noncontrast Brain MRI Effective for Monitoring Multiple Sclerosis
March 17, 2019 - Brain region plays key role in regulation of parenting behavior, study finds
March 17, 2019 - Natural speed limit on DNA replication sets pace for life’s first steps
March 17, 2019 - New research reveals overlooked impact of herbicide glyphosate on the environment
March 17, 2019 - Molecular patterns could help predict relapse risk in breast cancer patients
March 17, 2019 - Study confirms sensitivity of microbiological cultures for detecting cholera
March 17, 2019 - Scientists Spot Clues to Predicting Breast Cancer’s Return
March 17, 2019 - Scientists identify gene that keeps PTSD-like behavior at bay in female mice
March 17, 2019 - New method would allow doctors to detect earliest stages of cancers in the lymph nodes
March 17, 2019 - Cholesterol protein discovery raises hope for smarter drugs
Researchers identify a new way to prolong the circulation of cancer-fighting nanoparticles in the bloodstream

Researchers identify a new way to prolong the circulation of cancer-fighting nanoparticles in the bloodstream

image_pdfDownload PDFimage_print

For a number of innovative and life-saving medical treatments, from organ replacements and skin grafts to cancer therapy and surgery, success often depends on slipping past or fending off the body’s immune system. In a recent development, aimed at aiding cancer detection and treatment, Drexel University researchers might have found the ideal surface texture for helping microscopic, medical helpers to survive in the bloodstream without being screened out by the body’s natural defense mechanisms.

The researchers, led by Hao Cheng, PhD, an assistant professor in the Materials Science and Engineering Department of Drexel’s College of Engineering, have been studying how to prolong the life of nanoparticles in the body. These aptly named tiny organic molecules can be tailored to travel through the bloodstream, seek and penetrate cancerous tumors. With this ability, they’ve shown great promise, both as markers for tumors and tools for treating them. But at this point, a major limit on their effectiveness is how long they’re able to remain in circulation – hence Cheng’s pursuit.

“Most synthetic nanoparticles are quickly cleared in the bloodstream before reaching tumors. Short blood circulation time is one of the major barriers for nanoparticles in cancer therapy and some other biomedical applications,” Cheng said. “Our group is developing a facile approach that dramatically extends nanoparticle circulation in the blood in order to improve their anti-tumor efficacy.”

His latest discovery, published in the journal ACS Nano, shows that surface topography is the key to nanoparticle survival. Cheng’s research group shows how polymer shells can be used to cloak nanoparticles in the bloodstream from uptake by the immune system and liver – the body’s primary screeners for removing harmful intruders from circulation.

Getting ‘Flagged’

As soon as nanoparticles enter the bloodstream, plasma proteins immediately attach onto their surfaces, a process called “protein adsorption.” Some of these adsorbed proteins behave like a marker to label nanoparticles as foreign bodies, telling the immune system to remove them.

Previously, scientists believed that once the nanoparticles were “protein tagged” macrophages, the gatekeeper cells of immune system, would assume primary responsibility for clearing them from the blood. But Cheng’s research found that liver sinusoidal endothelial cells actually play an equally important role in scooping up bodily invaders.

“This was a somewhat surprising finding,” Cheng said. “Macrophages are normally considered the major scavenger of nanoparticles in the blood. While liver sinusoidal endothelial cells express scavenger receptors, it was largely unknown that reducing their uptake of nanoparticles could have an even more dramatic effect than efforts to prevent uptake by microphages.”

So to keep nanoparticles in circulation the researchers needed to develop a way to thwart both sets of cells.

Layering Up

The method currently used for keeping these cells at bay, is coating the nanoparticles with a polymer shell to reduce protein adsorption – thus preventing the particles from being targeted for removal.

Polyethylene glycol – PEG, for short – is the polymer widely used as the nanoparticle coating and one Cheng’s lab has employed in its previous work developing coatings for nanoparticles that can penetrate solid tumors. Researchers have shown that deploying PEG in a dense, brush-like layer can repel proteins; and grafting it less densely, in a form where the polymer stands look more like mushrooms, can also prevent protein adsorption.

But the Drexel researchers discovered that combining the two types of layers creates a nanoparticle coating that can thwart both proteins and the immune system’s “bouncer” cells.

“We found that it takes a mushroom on top of a brush to keep nanoparticles ‘invisible’ in the bloodstream,” said Christopher Li, PhD, a professor in the College of Engineering and co-author of the paper whose work focuses on engineering soft materials, such as polymers. “Our hierarchal bi-layer approach is a clever way to combine the advantages of both the brush configuration, as well as low-density PEG layers that form mushrooms.”

Staying in the Game

It turns out that with more space to spread out on a nanoparticle shell, PEG “mushrooms” wave like seaweed swinging in water, making nanoparticles difficult for macrophages and liver sinusoidal endothelial cells to scoop up. The dense inner layer of PEG brushes does its part to keep proteins away, thus making a formidable combination to prolong a nanoparticle’s trip in the bloodstream.

“For the first time, we are showing that a dynamic surface structure of nanomaterials is important for their fate in vivo,” said Hao Zhou, PhD, who was a doctoral student in Cheng’s lab and the lead author of the paper.

With the hierarchal polymer layers cloaking the outside of nanoparticles, Cheng found that they can remain in the bloodstream up to 24 hours. This is a twofold increase over the best results in previous nanoparticle studies and it means that a greater number of particles would be able to reach their ultimate destination inside tumors.

“This discovery suggests that we have identified the optimal PEG configuration for coating nanoparticles,” said Wilbur B. Bowne, MD, a cancer surgeon and professor in Drexel’s College of Medicine, who contributed to the paper. “Prolonging the circulation time to 24 hours expands the possibilities for using nanoparticles in cancer therapy and diagnosis.”

Source:

https://drexel.edu/now/archive/2018/October/mushroom-brush-NP/

About author

Related Articles