Tag: wound dressing

Categories : Medical Research & TechnologyTags :

Artificial Spider Silk: A Next-generation Medical Material

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Photo by Anthony Levlev on Unsplash

It’s almost time to dust off the Halloween decorations and adorn the house with all manner of spooky things, including the classic polyester spider webs. Scientists report in ACS Nano that they have made their own version of fake spider silk, but this one consists of proteins and heals wounds instead of haunting hallways. The artificial silk is strong enough to be woven into bandages that helped treat joint injuries and skin lesions in mice.

Spider silk is one of the strongest materials on Earth, technically stronger than steel for a material of its size. But it’s tough to obtain – spiders are too territorial (and cannibalistic!) to breed them like silkworms, leading scientists to turn to artificial options. Teaching microbes to produce the spider silk proteins through genetic engineering is one such option, but this has proved challenging because the proteins tend to stick together, reducing the silk’s yield. So, Bingbing Gao and colleagues wanted to modify the natural protein sequence to design an easily spinnable, yet still stable, spider silk using microbes.

The team first used these microbes to produce the silk proteins, adding extra peptides as well. The new peptides, following a pattern found in the protein sequence of amyloid polypeptides, helped the artificial silk proteins form an orderly structure when folded and prevented them from sticking together in solution, increasing their yield. Then, using an array of tiny, hollow needles attached to the nozzle of a 3D printer, the researchers drew the protein solution into thin strands in the air and spun them together into a thicker fibre. This setup acted like a giant artificial spider spinning its web.

They then wove their artificial silk fibres into prototype wound dressings that they applied on mice with osteoarthritis (a degenerative joint disease) and chronic wounds caused by diabetes. Drug treatments were easily added to the dressings, and the team found these modified dressings boosted wound healing better than traditional bandages. Compared with a control group with neutral dressings, mice with osteoarthritis showed decreased swelling and repaired tissue structure after 2 weeks of treatment, while diabetic mice with skin lesions treated with a similar dressing showed significant wound healing after 16 days of treatment. The new silken bandages are biocompatible and biodegradable, and the researchers say that they show promise for future applications in medicine.

Source: American Chemical Society

Categories : Injury & Trauma Regenerative MedicineTags :

Astronauts Will Test A Portable Bioprinter for Wounds

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ESA astronaut Matthias Maurer is shown during preflight training for the BioPrint First Aid investigation, which tests a bioprinted tissue patch for enhanced wound healing.
Credit: ESA

A suitably advanced piece of wound care technology will be sent into orbit to the space station in the next few days: a prototype for portable bioprinter that can cover a wound area on the skin by applying a tissue-forming bio-ink that acts like a patch, and accelerates the healing process.

While the aim is to provide a effective wound treatment for astronauts millions of kilometres from the nearest hospital, such a personalised wound healing patch would also have a great benefit on Earth. Since the cultured cells are taken from the patient, immune system rejection is unlikely, allowing a safe regenerative and personalised therapy. Other advantages are the possibilities of treatment and greater flexibility regarding wound size and position. In addition, due to its small size and portability, physicians could take the device anywhere to an immobile patient if their cells were cultivated in advance.

“On human space exploration missions, skin injuries need to be treated quickly and effectively,” said project manager Michael Becker from the German Space Agency. “Mobile bioprinting could significantly accelerate the healing process. The personalised and individual bioprinting-based wound treatment could have a great benefit and is an important step for further personalised medicine in space and on Earth.”

The use of bioprinting for skin reconstruction following burns is one growing application for the technology. However, it presently requires large bioprinters that first print the tissue, allow it to mature, before it is implanted onto the patient. By testing it in the gravity-free environment of space, Bioprint FirstAid will help optimise of bioprinting materials and processes. Microgravity-based 3D tissue models are important for greater understanding of the bioengineering and bio-fabrication requirements that are essential to achieve highly viable and functional tissues. Under microgravity conditions, the pressure of different layers containing cells is absent, as well as the potential sedimentation effect of living cell simulants. The stability of the 3D printed tissue patch, and the potentially gravity-dependent (electrolyte to membrane interface) crosslinking process, can be analysed for future applications.

The Bioprint FirstAid prototype contains no cells at this point. The surprisingly simple prototype is a robust, purely mechanical handheld bioprinter consisting of a dosing device in the handle, a print head, support wheels, and an ink cartridge. The cartridge contains a substitution (in total two different substitutions, both without skin cells) and a crosslinker, which serves as a stabilising matrix. To test it out, the simulant will be applied to the arm or leg of a crew member wrapped in foil, or alternatively at any other surface wrapped in foil. On Earth, a printed sample with human cells will be tested, and the distribution pattern will be compared to the cell-free sample that was printed in space.

Source: NASA

Categories : Injury & TraumaTags :

A New Wound Dressing With Built-in Sensors

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Image by Dian Polekhina on Unsplash

A research team has developed a smart wearable sensor that can conduct real-time, point-of-care assessment of chronic wounds wirelessly via an app. The world-first sensor technology can detect temperature, pH, bacteria type and inflammatory factors specific to chronic wounds within 15 minutes, enabling fast and accurate wound assessment.

More patients are suffering from non-healing wounds such as diabetic foot and chronic venous leg ulcers due to ageing and diabets, with an estimated 2% of the world’s population suffering from chronic wounds. Pain, stress and even amputation can result. Timely care and proper treatment of chronic wounds are needed to speed up wound recovery, but requires multiple clinical visits for lengthy wound assessment and treatment. This new technology can alleviate these problems.

The development of the technology was outlined in the journal Science Advances.

Currently, clinical assessments of wounds rely on visual inspection, or collecting and sending wound fluid for lab tests for biomarkers. This process usually takes about one to two days and may impede  medical interventions. Though flexible sensors designed for wound care have been developed, they can only probe a limited set of markers such as acidity, temperature, oxygen, uric acid, and impedance to diagnose wound inflammation.

VeCare is a response to these problems, a point-of-care wound assessment platform consisting of an innovative wound sensing bandage, an electronic chip and a mobile app. The bandage consists of a wound contact layer, a breathable outer barrier, a microfluidic wound fluid collector and a flexible immunosensor. VeCare is the first wound assessment platform that can detect bacteria type and probe inflammatory factors, in addition to measuring acidity and temperature, within a single 15-minute test. The microfluidic wound collector boosts delivery to the immunosensor for analysis.

In addition, the reusable integrated chip transmits data to an app for convenient, real-time wound assessment and analysis onsite.

The VeCare platform and mobile app enable doctors to monitor the condition of patients’ chronic wounds remotely, and complements the patient’s existing medical treatment while facilitating timely medical intervention for wound healing processes.

“Point-of-care devices coupled with telehealth or digital health capability can play a significant role in transforming the healthcare industry and our society, which is catalysed by the COVID-19 pandemic requirements for safe distancing. Our smart bandage technology is the first of its kind designed for chronic wound management to give patients the freedom to perform the test and monitor their wound conditions at home,” said research leader Professor Lim Chwee Teck from the National University of Singapore’s (NUS) Department of Biomedical Engineering.

A small clinical test of VeCare was conducted on patients with chronic venous leg ulcers, successfully demonstrating the platform’s effectiveness.
“The VeCare platform is easily scalable and customisable to accommodate different panels of biomarkers to monitor various types of wounds. The aim is to have an effective and easy to use diagnostic and prognostic tool for precise and data-driven clinical management of patients,” commented Prof Lim.

Next steps include a larger randomised trial and scaling up production to bring the device to market.

Source: National University of Singapore

Categories : Injury & Trauma Regenerative MedicineTags :

New Wound Dressing Minimises Scarring

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Photo by Diana Polekhina on Unsplash
Photo by Diana Polekhina on Unsplash

A new wound dressing technology that can stop bleeding while preventing infection and scarring using a single material, has been developed. This technology also has potential applications in drug delivery, among other areas.

“Scarring is one of the worst consequences of severe wounds,” said Xiaoyang Wu, an associate professor in the Ben May Department of Cancer Research at the University of Chicago, noting that scar tissue formation is particularly common in human skin.

The researchers used a material science approach to develop a new method to overcome scarring, by impeding collagen synthesis by blocking transforming growth factor beta (TGF-β) – a cytokine that plays an important role in cell signaling, both in skin wound repair and tissue fibrosis.

“Increasing evidence suggests TGF-β is important in early phase wound repair for wound closure. But, later on, the signal may promote and enhance scarring,” Prof Wu said. This makes timing crucial. “We cannot simply block the signal, because that would slow down wound healing and would be dangerous for the patient,” he explained.

To get around this, the researchers came up with a delayed-release system combining a sutureless wound closure hydrogel material with a biodegradable microcapsule system, enabling them to control the release of the TGF-β inhibitor. “In this way, we can enhance skin wound repair and after 7-14 days can release the inhibitor that blocks the skin scarring process at the same time by using one material,” Prof Wu added.

The study results were recently published in Nature Communications.

At present, treatment of scarring is not ideal with little besides cosmetic surgery, and little can be done to prevent scar formation if a patient experiences a deep or messy wound. “The system we developed is very convenient for application,” said Wu, adding that the system has many possible future applications, such as drug delivery.

“We believe the novel system will have potential clinical importance in the future,” he said. To this end, the next steps include filing an investigational new drug (IND) application with the US Food and Drug Administration (FDA). Consistent manufacturing of the material is necessary and the researchers are exploring collaborations with pharmaceutical companies to move the research forward.

Since the system is a biocompatible material with adhesive properties, Wu said it has internal applications as well, adhering to and closing bleeding arteries and cardiac walls after irradiation with UV light. This was demonstrated in animal models, suggesting significant advantages as a traumatic wound sealant.

“Normal wound binding material does work well,” said Wu, noting that fibres are the most reliable material currently available, which, like surgical glue, is less biocompatible. “Biocompatibility is a significant advantage of our system,” he explained, “It is superior compared to current existing materials.”

Source: University of Chicago