Category: Injury & Trauma

Astronauts Will Test A Portable Bioprinter for Wounds

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

Improved Wound Healing with Platelet-rich Plasma

Image by Dian Polekhina on Unsplash

New research suggests that wound healing could be enhanced by replicating platelet-rich plasma from our blood to create implants introduced into the wound.

Platelet-rich plasma (PRP) is a natural healing substance in our blood. Researchers explored ways of enhancing the wound healing process by extracting PRP from the blood of a patient with a complex skin wound and manipulating it through 3D printing to form an implant for tissue repair which can be used to treat difficult-to-heal skin wounds in a single surgical procedure.

The results, which are reported in Advanced Functional Materials, showed that application of the 3D-printed PRP implant helped to speed up the healing of the wound by enabling efficient vascularisation and inhibiting fibrosis, which are both essential for effective wound healing.

Professor Fergal O’Brien, at RCSI University of Medicine and Health Sciences said: “Existing literature suggests that while the PRP already present in our blood helps to heal wounds, scarring can still occur. By 3D-printing PRP into a biomaterial scaffold, we can increase the formation of blood vessels while also avoiding the formation of scars, leading to more successful wound healing.

“As well as promising results for skin wound healing, this technology can potentially be used to regenerate different tissues, therefore dramatically influencing the ever-growing regenerative medicine, 3D printing and personalised medicine markets.”

Source: RCSI

Exploring how Ischaemia-reperfusion Injuries Heal

Source: Wikimedia CC0

Researchers from Japan have discovered the role of interleukin-36 receptor antagonists in healing skin wounds from ischaemia-reperfusion injuries.

Ischaemia is a medical condition in which the blood supply is cut off to different parts of the body. In patients who are bed-ridden, ischemia can manifest as pressure ulcers. Else, it could be the Raynaud’s phenomenon in someone under severe stress. Ischaemia, from the Latin “staunching of blood”, is a condition can be rescued by blood reperfusion to the affected areas. However, ischaemia-reperfusion (I/R) injuries where tissue damage caused by blood returning to tissues after a period of oxygen deprivation, are a risk.

Skin-based I/R injuries can be exacerbated by inherited immunological mechanisms, for instance in patients who are otherwise showing signs of slow wound healing. To understand the immunological mechanisms underlying the development of this condition better, decided to narrow down their investigation to interleukin-36 receptor antagonist (IL-36Ra), a protein that plays a pivotal immunomodulatory role in wound healing.

Lead researcher Mr Yoshihito Tanaka from Fujita Health University School of Medicine explained the motivation behind the research, “We wanted to understand the immunological mechanisms involved in the healing of wounds from cutaneous ischaemia-reperfusion injuries, such as pressure ulcers and Raynaud’s phenomenon, to narrow down possible therapeutic targets. Drawing from experience, IL-36Ra appeared to be a promising candidate for kickstarting our investigation.”

The scientists used mice knocked out for the IL-36Ra receptor, and induced cutaneous I/R injuries in the knockout and control mice. Then, they studied corresponding immunological responses in both groups of animals, including wound healing time, infiltration of neutrophils/macrophages  to the site of the wounds, apoptotic skin cells, and activation of other unwanted immunological defense mechanisms. Their findings appear in the Journal of The European Academy of Dermatology and Venereology.

They found that the absence of IL-36Ra, indeed, significantly slows down wound healing in cutaneous I/R injuries, through increased apoptosis, or ‘suicide’ of useful skins cells, excessive recruitment of inflammatory cells, and employment of unnecessary proinflammatory mechanisms.

Additionally, they demonstrated the role of Cl-amidine, a protein-arginine deiminase inhibitor as effective in normalizing exacerbated I/R injury in IL-36Ra mice. Based on these observations, the scientists assert their findings are the first conclusive report of the involvement of IL-36Ra in cutaneous I/R injury.

The researchers believe IL-36Ra is a good therapeutic candidate against cutaneous I/R injuries. As Mr. Tanaka optimistically adds, “Our research may lead to the development of therapeutic agents for wound healing of various other refractory skin diseases too.”

The quest for novel therapeutic targets in skin wound healing might just have been empowered by these findings of the team and the future indeed looks brighter for alleviating the painful burden of cutaneous I/R injuries.

Source: Fujita Health University School of Medicine

A New Wound Dressing With Built-in Sensors

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

Massage Heals Injured Muscle by Getting Immune Cells Out

Photo by Andrea Piacquadio from Pexels

While massage has been used to treat muscle pain and injury for thousands of years, it is only now that a study has scientifically confirmed that it improves recovery and strength gains. Intriguingly, the mechanism behind this is mechanically clearing out of immune cells from the injury site after they have done their job.

Using a custom-designed robotic system massage system for mice, the team found that this mechanical loading (ML) rapidly clears immune cells called neutrophils out of severely injured muscle tissue. This process also removed inflammatory cytokines released by neutrophils from the muscles, enhancing the process of muscle fiber regeneration. The research is published in Science Translational Medicine.

“Lots of people have been trying to study the beneficial effects of massage and other mechanotherapies on the body, but up to this point it hadn’t been done in a systematic, reproducible way. Our work shows a very clear connection between mechanical stimulation and immune function. This has promise for regenerating a wide variety of tissues including bone, tendon, hair, and skin, and can also be used in patients with diseases that prevent the use of drug-based interventions,” said first author Bo Ri Seo, PhD.

Dr Seo and her colleagues previously found in mouse studies that mechanical massage of injured muscles doubled the rate of muscle regeneration and reduced tissue scarring over the course of two weeks. With a new device inspired by soft robotics, the researchers sought to confirm these results. They found that the greater the force applied, the stronger the injured muscles became.

In vitro experiments suggested that neutrophil-secreted factors stimulate the growth of muscle cells, but the prolonged presence of those factors impairs the production of new muscle fibres. In vivo testing showed that stronger muscle fibre types predominated in treated, injured muscle types. Depleting neutrophils in mice after the third day resulted in greater strength recovery, indicating that they are important in the initial recovery period but removing them from the injury site early leads to improved muscle regeneration.

“The idea that mechanics influence cell and tissue function was ridiculed until the last few decades, and while scientists have made great strides in establishing acceptance of this fact, we still know very little about how that process actually works at the organ level. This research has revealed a previously unknown type of interplay between mechanobiology and immunology that is critical for muscle tissue healing, in addition to describing a new form of mechanotherapy that potentially could be as potent as chemical or gene therapies, but much simpler and less invasive,” said Don Ingber, MD, PhD, founding director of the Wyss Institute for Biologically Inspired Engineering at Harvard.

Source: Wyss Institute for Biologically Inspired Engineering at Harvard

The Nagging Pain of Vaccination Shoulder Injuries

Image source: NCI on Unsplash

Shoulder injury related to vaccine administration (SIRVA) has been documented long before COVID, and most commonly reported after influenza vaccination. The cause is often due to poor administration. 

However, the medical community cautions that currently it’s more of a medicolegal determination rather than a distinct diagnosis. The condition is also plagued by the lack of a solid evidence base, and causality is difficult to pin down.

However, most physicians that MedPage Today interviewed put shoulder injury down to improper injection technique, and that these problems should be taken seriously and treated appropriately. One recent overview noted that SIRVA is a “rare yet increasingly recognised complication of immunisation.”

“We’re certainly not seeing a pandemic of SIRVA” from COVID vaccines, said Dr DJ Kennedy, chair of physical medicine & rehabilitation at Vanderbilt University Medical Center. “It’s really rare and the literature to date is mostly case reports. But I do think it’s possible, absolutely” for vaccine-related shoulder injury to occur.

Dr Laura Keeling, orthopedic surgeon at MedStar Georgetown University Hospital, told MedPage Today that part of the reason SIRVA remains in the medicolegal realm is that it’s “more of a constellation of symptoms and findings” as opposed to a specific diagnosis.

Symptoms can vary depending on where the stray shot landed, resulting in various manifestations such as bursitis, tendonitis, or adhesive capsulitis (aka ‘frozen shoulder’).

Generally, it’s characterised as a “constellation of shoulder pain and reduced range of motion that occurs within 48 hours of vaccination and does not resolve within 1 week,” according to a recent paper co-authored by Dr Keeling. It’s also different from typical post-injection soreness, as the pain is more severe and it can impact mobility and function.

Generally, treatments include anti-inflammatory drugs, corticosteroid injections, and physical therapy. Occasionally surgery is necessary to treat an underlying pathology such as an exacerbated rotator cuff injury. Patients with SIRVA often land in their GP’s office first, and then may be referred to a specialist such as a physiatrist or an orthopedic surgeon.

“It’s the patients who have persistent symptoms who are referred to orthopedic surgeons,” Dr Keeling said. “If physical therapy and injection don’t work, then primary care refers to us.”

Physical medicine & rehabilitation physicians, or physiatrists, also play a large role in treating SIRVA.

“We treat based on a full evaluation including history and physical findings, and imaging if needed,” Dr Kennedy said. “Then we develop a comprehensive rehabilitation plan … that usually involves doing range of motion and strengthening exercises on a daily basis.”

Scott Noren, DDS, an oral surgeon in Ithaca, New York, said after his second COVID shot in early February, he developed shoulder pain: “It went in pretty deep and pretty high,” he told MedPage Today.

An MRI revealed fluid collecting in his joint, as well as adhesive capsulitis, he said. Physical therapy helped improve his range of motion to an extent, but he has lingering pain. It’s difficult to take x-rays and do long procedures as an oral surgeon: “I have pretty good pain even with just normal function now,” he said.

Source: MedPage Today

New Wound Dressing Minimises Scarring

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

New Insights into First Stages of Wound Healing

Photo by cottonbro from Pexels
Photo by cottonbro from Pexels

A new study from Vanderbilt University researchers has revealed how cells detect and react to wounds.

The epithelial cells which cover the body and its organs, must be able to heal wounds, as they are constantly exposed to insults and abrasion. “When these cells detect a wound nearby, they change their behaviours,” said study co-leader Professor Andrea Page-McCaw in the Department of Cell and Developmental Biology. “They transition from stationary, nondividing, noninvasive cells to cells that migrate, divide and invade.” This also describes the behaviors of cancer cells, which adopt wound-healing behaviours without any wound.

The researchers began with focusing on epithelial cells’ first known reaction of to a nearby wound: an increase in calcium levels, which typically occurs within a minute of wounding.

“We were able to connect the response of these cells directly to the cellular damage inherent in wounding,” Prof Page-McCaw said. “We found that wounds destroy cells, causing them to leak or even burst, and some of their contents get out. Outside of cells, tissues have a detector molecule ready to sense these cellular contents. When they do, proteases in the cellular contents chop up the detector molecule into smaller pieces, which spread to nearby cells. This activates receptors on the cells’ surfaces, giving them the information that a wound is nearby.”

Successful and efficient wound healing is key for recovery from trauma or surgery, and this study improves the understanding of how wounds are recognised by epithelial cells and how this leads to wound healing. This will help develop therapeutics that can address this health issue.

Slow wound healing time can be caused by a number of factors, such as diabetes, and can lead to infection and declining health. By figuring out how to downregulate these wound-healing behaviours in combination with other cancer interventions, this work offers insights that could help combat cancer’s adoption of this mechanism.

The researchers will next focus on how cells use the information they receive about the presence of a wound, specifically how the information is encoded in the calcium signal dynamics and then converted into migration, proliferation and changes in cell- and tissue-level mechanics. “Now that we have a solid understanding of how the presence of a wound is first signaled to nearby cells, we can ask a lot of interesting follow-up questions,” said study co-leader Shane Hutson, chair of the Department of Physics and Astronomy and professor of physics and biological sciences. “How much information is present in those signals? Can cells interpret the signals to know how large the wound is or how far they are from the wound? Do they use the way the dynamic signals change with time to make that measurement? What are the detailed mechanisms by which the signals then get turned into cellular actions?”

Source: Vanderbilt University

Journal information: James T. O’Connor et al, Proteolytic activation of Growth-blocking peptides triggers calcium responses through the GPCR Mthl10 during epithelial wound detection, Developmental Cell (2021). DOI: 10.1016/j.devcel.2021.06.020

New Wound Healing Scoring System Proposed

Photo by Tara Winstead from Pexels

Researchers have proposed a new scoring system for wound healing in mice based on parameters in each phase of healing.

The researchers described the system in an article in the peer-reviewed journal Stem Cells and Development.

Wound healing processes consist of a sequence of molecular and cellular events which occur after the onset of a tissue lesion in order to restore the damaged tissue. In order to evaluate the efficacy of new treatments, there is a need to monitor wound progression accurately and reproducibly over time. 

The parameters include re-epithelisation, epithelial thickness index, keratinisation, granulation tissue thickness, remodeling, and the scar elevation index. These parameters can be assessed using either Hematoxylin & Eosin or Masson’s Trichrome staining. Mari van de Vyver, from Stellenbosch University, and colleagues developed this histology scoring system for cutaneous wounds in mice. They then validated the system in four different types of murine skin wound models.

“This histological scoring system defines and describes the minimum recommended criteria for assessing wound healing dynamics,” state the authors. “The experience and ability of investigators to accurately identify structures in histology slides at different stages of healing is crucial for consistency and repeatability of measures to deliver meaningful results.”

“The development and validation of this scoring system in a randomized blinded investigation by researchers from Stellenbosch University (South Africa), Polish Academy of Sciences in Olsztyn (Poland), University of Texas Southwestern Medical Center (Texas, USA) and Obatala Sciences Inc. (New Orleans, USA) represents a truly international effort to advance the robust and accurate assessment of wound healing,” stated Graham C Parker, PhD, Editor-in-Chief of Stem Cells and Development and The Carman and Ann Adams Department of Pediatrics, Wayne State University School of Medicine, Detroit, MI.

Source: Mary Ann Liebert, Inc.

Journal information: van de Vyver, M., et al. (2021) Histology Scoring System for Murine Cutaneous Wounds. Stem Cells and Development.doi.org/10.1089/scd.2021.0124.

Good Outcomes for Severe Brain Injury Still Possible

Photo by Anna Shvets from Pexels

A new study adds to the growing body of evidence that decisions regarding moderate-to-severe traumatic brain injury (TBI) should not be made too soon after the injury, as a good prognosis can still emerge.

Researchers followed 484 patients with moderate-to-severe TBI and found that among the patients in a vegetative state, one quarter “regained orientation” — awareness of who, when and where they were —  within 12 months of their injury.

“Withdrawal of life-sustaining treatment based on early prediction of poor outcome accounts for most deaths in patients hospitalised with severe TBI,” said senior author Geoffrey Manley, MD, PhD,  noting that 64 of the 92 fatalities in the study occurred within two weeks of injury. Dr Manley is professor and vice chair of neurological surgery at UCSF and chief of neurosurgery at Zuckerberg San Francisco General Hospital.

“TBI is a life-changing event that can produce significant, lasting disability, and there are cases when it is very clear early on that a patient will not recover,” he said. “But results from this study show a significant proportion of our participants experienced major improvements in life functioning, with many regaining independence between two weeks and 12 months after injury.”

The patients in the study were enrolled by the brain injury research initiative TRACK-TBI, of which Dr Manley is the principal investigator. All patients were 17 and older and had presented to hospitals with level 1 trauma centers within 24 hours of injury. Their exams met criteria for either moderate TBI or severe TBI. The causes were falls, assault and primarily crashes involving a motor vehicle.

The patients, whose average ages were 35 in the severe TBI group (78 percent males) and 38 in the moderate TBI group (80 percent males), were assessed using the Glasgow Outcomes Scale Extended (GOSE), which ranges from 1 for death to 8 for “upper good recovery” and resumption of normal life. Impairment was also categorised with the Disability Rating Scale (DRS).

At two weeks post-injury, 93 percent of the severe TBI group and 79 percent of the moderate TBI group had moderate-to-severe disability, according to the DRS, and 80 percent had GOSE scores from 2 to 3, meaning they required assistance in basic everyday functioning.

But by 12 months, half of the severe TBI group and three-quarters of the moderate TBI group had GOSE scores of at least 4, indicating they could function independently at home for at least eight hours per day. Moreover, 19 percent of the severe TBI group had no disability, according to the DRS, and a further 14 percent had only mild injury, the researchers noted.

Most surprising were the findings for the 62 surviving patients who had been in a vegetative state. By the 12-month mark all patients had recovered consciousness and 1 in 4 had regained orientation. All but one survivor in this group recovered at least basic communication ability.

“These patients made the cut for favorable outcome,” said co-first author, Joseph Giacino, PhD, of Spaulding Rehabilitation Hospital, Massachusetts General Hospital and Harvard Medical School. “Their GOSE scores were 4 or higher, which meant they could be at home unsupervised for at least eight hours a day, since they were able to take care of basic needs, such as eating and toileting.”

In prior work, a significant percentage of patients with grave impairments had been shown to achieve favorable functionality after many months or years. This study coincided with the recommendation in 2018 from the American Academy of Neurology that in the first 28 days after injury, clinicians should refrain from telling families that a patient’s prognosis is beyond hope.

“While a substantial proportion of patients die or suffer lasting disability, our study adds to growing evidence that severe acute impairment does not portend uniformly poor long-term outcome,” said Manley, who is also affiliated with the UCSF Weill Institute for Neurosciences. “Even those patients in a vegetative state – an outcome viewed as dire – may improve, since this is a dynamic condition that evolves over the first year.”

Source: University of California, San Francisco

Journal information:JAMA Neurology (2021). DOI: 10.1001/jamaneurol.2021.2043