Tag Archives: nanotechnology

Implants Without Risk Of Infection

Researchers at McMaster (Canada) have solved a vexing problem by engineering surface coatings that can repel everything, such as bacteria, viruses and living cells, but can be modified to permit beneficial exceptionsThe discovery holds significant promise for medical and other applications, making it possible for implants such as vascular grafts, replacement heart valves and artificial joints to bond to the body without risk of infection or blood clotting. The new nanotechnology has the potential to greatly reduce false positives and negatives in medical tests by eliminating interference from non-target elements in blood and urine.

The research adds significant utility to completely repellent surfaces that have existed since 2011. Those surface coatings are useful for waterproofing phones and windshields, and repelling bacteria from food-preparation areas, for example, but have offered limited utility in medical applications where specific beneficial binding is required

 

It was a huge achievement to have completely repellent surfaces, but to maximize the benefits of such surfaces, we needed to create a selective door that would allow beneficial elements to bond with those surfaces,” explains Tohid Didar of McMaster’s Department of Mechanical Engineering and School of Biomedical Engineering, the senior author of a paper that appears today in the journal ACS Nano.

In the case of a synthetic heart valve, for example, a repellent coating can prevent blood cells from sticking and forming clots, making it much safer.

A coating that repels blood cells could potentially eliminate the need for medicines such as warfarin that are used after implants to cut the risk of clots,” says co-author , a McMaster PhD student in Biomedical Engineering. Still, she explains, a completely repellent coating also prevents the body from integrating the new valve into the tissue of the heart itself.

By designing the surface to permit adhesion only with heart tissue cells, the researchers are making it possible for the body to integrate the new valve naturally, avoiding the complications of rejection. The same would be true for other implants, such as artificial joints and stents used to open blood vessels.

If you want a device to perform better and not be rejected by the body, this is what you need to do,” says co-author Maryam Badv, also a McMaster PhD student in Biomedical Engineering. “It is a huge problem in medicine.”

Source: https://brighterworld.mcmaster.ca/

How To Treat Oral Plaque Without Drugs

When the good and bad bacteria in our mouth become imbalanced, the bad bacteria form a biofilm (aka plaque), which can cause cavities, and if left untreated over time, can lead to cardiovascular and other inflammatory diseases like diabetes and bacterial pneumonia.

A team of researchers from the University of Illinois has recently devised a practical nanotechnology-based method for detecting and treating the harmful bacteria that cause plaque and lead to tooth decay and other detrimental conditions.

Oral plaque is invisible to the eye so dentists currently visualize it with disclosing agents, which they administer to patients in the form of a dissolvable tablet or brush-on swab. While useful in helping patients see the extent of their plaque, these methods are unable to identify the difference between good and bad bacteria.

In this illustration, nanoparticles attach to or are taken up by the bacteria cells. Pan and his students are the first group to demonstrate that early detection of dental plaque in the clinic is possible using the regular intraoral X-ray machine which can seek out harmful bacteria populations.

Presently in the clinic, detection of dental plaque is highly subjective and only depends on the dentist’s visual evaluation,” said Bioengineering Associate Professor Dipanjan Pan, head of the research team. “We have demonstrated for the first time that early detection of dental plaque in the clinic is possible using the regular intraoral X-ray machine which can seek out harmful bacteria populations.

In order to accomplish this, Fatemeh Ostadhossein, a Bioengineering graduate student in Pan’s group, developed a plaque detection probe that works in conjunction with common X-ray technology and which is capable of finding specific harmful bacteria known as Streptococcus mutans (S. mutans) in a complex biofilm network. Additionally, they also demonstrated that by tweaking the chemical composition of the probe, it can be used to target and destroy the S. mutans bacteria.

The probe is comprised of nanoparticles made of hafnium oxide (HfO2), a non-toxic metal that is currently under clinical trial for internal use in humans. In their study, the team demonstrated the efficacy of the probe to identify biochemical markers present at the surface of the bacterial biofilm and simultaneously destroy S. mutans. They conducted their study on Sprague Dawley rats.

In practice, Pan envisions a dentist applying the probe on the patient’s teeth and using the X-ray machine to accurately visualize the extent of the biofilm plaque. If the plaque is deemed severe, then the dentist would follow up with the administering of the therapeutic HfO2 nanoparticles in the form of a dental paste.

In their study, the team compared the therapeutic ability of their nanoparticles with Chlorhexidine, a chemical currently used by dentists to eradicate biofilm. “Our HfO2nanoparticles are far more efficient at killing the bacteria and reducing the biofilm burden both in cell cultures of bacteria and in [infected] rats,” said Ostadhossein, noting that their new technology is also much safer than conventional treatment.

Source: https://bioengineering.illinois.edu/

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