Researchers have found evidence suggesting that the P.1 COVID variant could be twice as transmissible as prior strains. The findings were published in the Journal Science.
The P.1 SARS-CoV-2 variant was first detected in four travellers from Brazil during a routine screening at Haneda airport, Tokyo. Manaus, the capital of the state of Amazonas in Brazil was the origin of the variant. According to preliminary investigations, the virus emerged late in 2020, beginning to spread in November and then quickly became the dominant strain. This prompted many to believe that it could reinfect those infected with the initial strain.
Some 70% of the residents in the city were believed to have been infected during the initial infection period. After variant infections rose in Manaus, the P.1 variant soon spread throughout Brazil, and then to other countries—thus far, it has been detected in at least 37 countries.
The researchers used molecular clock analysis to determine that the virus had 17 identifiable mutations and that three spike protein mutations (N501Y, E484K and K417T) allowed the virus to bind more effectively to host cells. These also may help in evading antibodies, and the researchers also found that P.1 can evade immunity granted by prior strains.
In simulations, P.1 was 1.7 to 2.4 times more transmissible than the prior virus baseline, but whether this was due to longer persistence in the body or increased viral load could not be determined. Additionally, it could not be established if it increased disease severity or raised mortality rates. Though people inffected with the variant were 1.2 to 1.9 times as likely to die, this could have been a result of the severe strain the overburdened healthcare systems were experiencing in the city.
More work is needed to find out whether the P.1 strain can infect those infected with prior strains or have been vaccinated, the researchers said.
Journal information: Nuno R. Faria et al. Genomics and epidemiology of the P.1 SARS-CoV-2 lineage in Manaus, Brazil, Science (2021). DOI: 10.1126/science.abh2644
A US study uploaded onto the bioRxiv preprint server showed that pets with SARS-CoV-2 likely acquired the virus from humans.
This suggests that human-animal infection may actually occur much more frequently than previously thought – implying that infected individuals should limit their contact with animals. The paper is currently available on the bioRxiv* preprint server.
Both natural and experimental infections with SARS-CoV-2 have been demonstrated in various species of pets, which includes dogs, cats, hamsters, rabbits, and ferrets. Hamsters, cats and ferrets have been shown to transmit the virus to each other, and dogs are still weakly susceptible to the virus. However, natural infections of pets have almost always resulted from contact with a COVID-infected person.
Since pets share so much space with humans, this is a good use of the One Health approach, a transdisciplinary collaboration aiming for health outcomes through awareness of the interconnectedness between people, animals, plants and their mutual environment.
As part of a COVID household transmission investigation, researchers in the US conducted a One Health appraisal of SARS-CoV-2 infection in pet cohabitants as one of the earliest research endeavours in assessing risk and behavioral factors shared between people and pets.
The study was conducted between April and May of 2020, and mammalian pets from households with at least one individual with confirmed COVID were eligible for inclusion. Detailed descriptions of each animal’s residence were made.
Demographic and exposure information was obtained from all household members. At the same time, the pets were tested with the use of real-time reverse transcription-polymerase chain reaction (rRT-PCR) and neutralisation assays from oropharyngeal, nasal, rectal, fur, faecal, and blood samples.
The small sample size of this study made it difficult to analyse prevention measures in the home, so additional investigations are needed in order to determine the best methods to prevent human-pet COVID transmission.
All oropharyngeal, nasal, and rectal swabs from the tested animals tested negative when rRT-PCR was conducted; however, fur swabs from the one dog tested positive with the use of this molecular method at the first animal sampling. This is actually the first study to detect RNA of a virus from an animal’s fur.
Furthermore, in households where owners withs COVID lived with their pets, 20% had pets with serological evidence of prior SARS-CoV-2 infection, implying some secondary viral transmission. Four dogs and four cats from six households were found to have detectable neutralising antibodies against the virus.
In households with higher rates of human COVID infections, SARS-CoV-2 was more likely to be seen in pets, while much less common when owners limited interactions with their pets after they had developed COVID symptoms.
The authors stressed that it is still important for decision-makers to understand the role of animals in the epidemiology of the pandemic
“Our findings add to the growing body of evidence demonstrating SARS-CoV-2 transmission can occur between people and pets – most often from people to pets – and suggest this transmission may occur more frequently than previously recognized”, wrote the authors of the bioRxiv paper.
A study published in the journal Cell has announced the creation of human-monkey chimeric embryos, igniting renewed debate over ethics.
The embryos are known as chimeras, organisms whose cells come from two or more “individuals”, and in this case, different species: a long-tailed macaque and a human. The research confirmed that the cells can survive and multiply.
Natural human chimeras do exist, and can involve humans cells from two embryos in the same womb fusing to produce a single individual, or a combination of maternal and foetal cells, or monozygotic twins sharing blood cells from a shared placenta.
Previously, researchers had produced pig or sheep embryos that contained human cells, in an effort to one day develop a way to grow human organs for transplant inside the animals.
The researchers, led by Prof Juan Carlos Izpisua Belmonte from the Salk Institute in the US, said that the results shed new light on the communications pathways between cells of different species. This could help with future efforts to engineer chimeras using more distantly related species.
“These results may help to better understand early human development and primate evolution and develop effective strategies to improve human chimerism in evolutionarily distant species,” the authors wrote.
In 2019, the Spanish newspaper El País reported on rumours that a team of researchers led by Belmonte had created monkey-human chimeras.
Specific human foetal cells called fibroblasts were reprogrammed to become stem cells, and were then introduced into 132 embryos of long-tailed macaques, six days after fertilisation.
“Twenty-five human cells were injected and on average we observed around 4% of human cells in the monkey epiblast,” said Dr Jun Wu, a co-author of the research, and now at the University of Texas Southwestern Medical Center.
The embryos were grown in petri dishes and were terminated 19 days after the stem cells were injected. The human cells were engineered with a fluorescent protein to enable identification.
The researchers reported that 132 embryos contained human cells on day seven after fertilisation. However, the proportion containing human cells fell over time.
“We demonstrated that the human stem cells survived and generated additional cells, as would happen normally as primate embryos develop and form the layers of cells that eventually lead to all of an animal’s organs,” Belmonte said.
The researchers also found differences in intercellular interactions between human and monkey cells within chimeric embryos, compared to the normal monkey embryos.
The researchers hoped the research would help develop “transplantable human tissues and organs in pigs to help overcome the shortages of donor organs worldwide”, said Wu.
Prof Robin Lovell-Badge, a developmental biologist from the Francis Crick Institute in London, said at the time of the El País report he was not concerned about the ethics of the experiment, noting the team had only produced a ball of cells. But he noted conundrums could arise in the future should the embryos be allowed to develop further.
While not the first attempt at making human-monkey chimeras – another group reported such experiments last year – the new study has reignited such concerns. Prof Julian Savulescu, the director of the Oxford Uehiro Centre for Practical Ethics and co-director of the Wellcome Centre for Ethics and Humanities at the University of Oxford, said the research had raised all sorts of ethical concerns.
“These embryos were destroyed at 20 days of development but it is only a matter of time before human-nonhuman chimeras are successfully developed, perhaps as a source of organs for humans,” he said, and added that a key ethical concern was the moral status of such organisms.
“Before any experiments are performed on live-born chimeras, or their organs extracted, it is essential that their mental capacities and lives are properly assessed. What looks like a nonhuman animal may mentally be close to a human,” he said. “We will need new ways to understand animals, their mental lives and relationships before they are used for human benefit.”
Others were less concerned, and rather pointed out that all the study found was that the creation of such chimera was simply ineffective.
Dr Alfonso Martinez Arias, an affiliated lecturer in the department of genetics at the University of Cambridge, said: “I do not think that the conclusions are backed up by solid data. The results, in so far as they can be interpreted, show that these chimeras do not work and that all experimental animals are very sick.
“Importantly, there are many systems based on human embryonic stem cells to study human development that are ethically acceptable and in the end, we shall use this rather than chimeras of the kind suggested here.”
With 100 days remaining until the Tokyo Olympic and Paralympic games, experts urge that the organisers must urgently reconsider plans to hold the games this summer.
Writing in The BMJ, Kazuki Shimizu at the London School of Economics and Political Science and colleagues said that the trajectory of the pandemic is still highly uncertain, warning that international mass gathering events such as Tokyo 2020 “are still neither safe nor secure”.
They say instead that “we must accelerate efforts towards containing and ending the pandemic by maintaining public health and social measures, promoting behavior change, disseminating vaccines widely, and strengthening health systems.”
While considerable scientific advancements have taken place over the past year, they said that vaccine roll-out has been inequitable, with many low and middle income countries having reduced access.
While a special scheme for vaccinating athletes orchestrated by the Olympics Organising Committee may help save lives, they argued that “it could also encourage vaccine diplomacy, undermine global solidarity (including the Covax global access scheme), and promote vaccine nationalism.”
Another concern that they highlighted was the fact that Japan, unlike neighbouring countries in the Asia-Pacific region, still has not achieved COVID containment.
“Even healthcare workers and other high risk populations will not have access to vaccines before Tokyo 2020, to say nothing of the general population,” they write.
In order to effectively protect participants from COVID, “Japan must develop and implement a clear strategy to eliminate community transmission within its borders, as Australia did before the Australian Open tennis tournament.”
Japan and the International Olympic Committee must also agree to operational plans based on robust science and share them with the international community, they added.
Waiving quarantine for incoming athletes, officials, broadcasters, press, and marketing partners “risks importing and spreading covid-19 variants of concern” and while international spectators will be excluded from the games, “cases could rise across Japan and be exported globally because of increased domestic travel – as encouraged by Japan’s official campaigns in 2020.” However, a recent survey indicated that 70% of Japanese would not want to attend the Olympic Games, due to COVID.
An overwhelmed healthcare system combined with an ineffective test trace and isolate scheme “could seriously undermine Japan’s ability to manage Tokyo 2020 safely and contain any outbreak caused by mass mobilization,” they write.
They also highlight the fact that there has been very little about the Paralympic games through official channels, and how the health and rights of disabled people will be protected during international competition. “The whole global community recognizes the need to contain the pandemic and save lives. Holding Tokyo 2020 for domestic political and economic purposes – ignoring scientific and moral imperatives – is contradictory to Japan’s commitment to global health and human security,” they argued.
“We must reconsider this summer’s games and instead collaborate internationally to agree a set of global and domestic conditions under which international multisport events can be held in the years ahead. These conditions must embody both Olympic and Paralympic values and adhere to international principles of public health,” they concluded.
Encapsulated clusters of noroviruses which can cause stomach flu have been found to be resistant to detergent and ultraviolet disinfection.
Noroviruses are the leading cause of gastroenteritis around the world, with more than 21 million cases annually in the United States. The findings of this study show that there is a need to revise current disinfection, sanitation and hygiene practices which serve to protect against infection with noroviruses.
In 2018, the research team had found that noroviruses can be transmitted to humans in the form of membrane-enclosed packets that contain clusters of viruses. Previously, it was thought that viruses spread via exposure to individual virus particles, but the 2018 study, , showed how membrane-enclosed clusters arrive at a human cell and release a large number of viruses.
For the new study, Drs Danmeng Shuai, Nihal Altan-Bonnet and the study’s first author Mengyang Zhang, a doctoral student co-advised through a GW/NIH Graduate Partnerships Program, examined how such protected virus clusters behave in the environment. They found that the virus clusters could survive disinfection attempts with detergent solutions or even UV light. Water treatment plants use UV light to kill noroviruses and other pathogens, and is being widely used in the COVID pandemic.
“These membrane-cloaked viruses are tricky,” explained study co-author Danmeng Shuai, PhD, associate professor of civil and environmental engineering, George Washington University. “Past research shows they can evade the body’s immune system and that they are highly infectious. Our study shows these membrane enclosed viruses are also able to dodge efforts to kill them with standard disinfectants.”
“We have to consider these viral clusters cloaked in vesicle membranes as unique infectious agents in the public health arena,” added Nihal Altan-Bonnet, PhD, a senior investigator and the head of the Laboratory of Host-Pathogen Dynamics at the National Heart, Lung, and Blood Institute. “When it comes to virulence -; and now with this study, disinfection and sanitation -; the sum is much more than its parts. And these clusters are endowed with properties that are absent from other types of viral particles.”
Future studies are needed to determine whether certain kinds of cleaning solutions or more UV light exposure would degrade the protective membrane and/or kill the viruses inside. Such research would hopefully come up with improved disinfection methods that could be used for cleaning surfaces in the home, in restaurants and in places where norovirus can spread and cause outbreaks, like cruise ships.
“Our study’s findings represent a step towards recommendations for pathogen control in the environment, and public health protection,” Dr Altan-Bonnet said.
Journal information: Zhang, M., et al. (2021) Emerging Pathogenic Unit of Vesicle-Cloaked Murine Norovirus Clusters is Resistant to Environmental Stresses and UV254 Disinfection. Environmental Science and Technology. doi.org/10.1021/acs.est.1c01763.
A team of scientists from the UK and Australia have discovered that single neurons can store electrical patterns, similar to memories. This represents a breakthrough towards solving how neural systems are able to process and store information.
By comparing predictions from mathematical modeling to lab-based experiments with mammalian neurons, they were able to determine how different parameters, such as how long it takes for neuronal signals to be processed and how sensitive a cell is to external signals, affect how neural systems encode information.
The research team found that a single neuron is able to select between different patterns, dependent on the properties of each individual stimulus, for example slight differences in stimulation timing resulted in the emergence of no electrical activity spikes, single spikes per delay or two spikes per delay,
By opening up new avenues into research on the encoding of information in the brain and how this relates to memory formation, the study could also allow new insights into the causes and treatments of mental health conditions such as dementia.
“This work highlights how mathematical analysis and wet-lab experiments can be closely integrated to shed new light on fundamental problems in neuroscience,” said Dr Wedgwood. “That the theoretical predictions were so readily confirmed in experiments gives us great confidence in the mathematical approach as a tool for understanding how individual cells store patterns of activity. In the long run, we hope that this is the first step to a better understanding of memory formation in neural networks.”
Professor Krauskopf from the University of Auckland remarked, “The research shows that a living neuron coupled to itself is able to sustain different patterns in response to a stimulus. This is an exciting first step towards understanding how groups of neurons are able to respond to external stimuli in a precise temporal manner.”
“Communication between neurons occurs over large distances. The communication delay associated with this plays an important role in shaping the overall response of a network. This insight is crucial to how neural systems encode memories, which is one of the most fundamental questions in neuroscience,” added Professor Tsaneva from the University of Exeter’s Living Systems Institute.
Journal information: Kyle C. A. Wedgwood et al, Robust spike timing in an excitable cell with delayed feedback, Journal of The Royal Society Interface (2021). dx.doi.org/10.1098/rsif.2021.0029
In the journal BMJ Case Reports, doctors have warned that heavy energy drink consumption may be linked to heart failure, after treating a 21 year old man who had drunk 2 litres of the drinks every day for 2 years.
This report adds to the growing body of published evidence on, and mounting concerns about, the potential heart harms of these drinks, the authors stated.
The young man in the case report experienced 4 months of progressive shortness of breath on exertion, breathlessness while lying down (orthopnoea), and weight loss before ending up in intensive care.
He habitually drank an average of four 500 ml cans of energy drink every day: each can contains 160 mg of caffeine plus taurine (a protein included in energy drinks for its cytoprotective benefits) and various other ingredients. He said he had been doing this for around 2 years. In the past he had also suffered bouts of indigestion, tremor and palpitations for which he hadn’t sought medical help. In the 3 months before he was admitted to hospital, he had discontinued his university studies because he was feeling so unwell and lethargic.
Testing revealed heart and kidney failure, both of which were severe enough to consider putting him on the list for a dual organ transplant. The kidney failure was due to an unrelated condition.
However, his heart symptoms and function improved significantly with drug treatment and after he cut out energy drinks completely. “However, it is difficult to predict the clinical course of recovery or potential for relapse,” caution the authors.
The authors noted that besides this case report, there have been several others as well as review articles that have highlighted mounting concerns about the potential cardiovascular system harms of energy drinks.
The authors theorised that one factor may be caffeine overstimulating the sympathetic nervous system; energy drinks are also known to increase blood pressure and can trigger heart rhythm abnormalities.
“Clear warnings should be provided about the potential cardiovascular dangers of energy drink consumption in large amounts,” the authors concluded.
“I think there should be more awareness about energy drinks and the effect of their contents,” added the subject of this case report. “I believe they are very addictive and far too accessible to young children.”
Black barbershops with pharmacist-led blood pressure (BP) care for their clients, have been shown to be cost effective, with the high initial costs offsetting reduced cardiovascular events later in life.
The study cost simulations were based on the original Los Angeles Barbershop Blood Pressure Study (LABBPS). In that study, intervention consisted of a trial with men being assigned either to barbershops where barbers encouraged patrons to meet with pharmacists who prescribed drug therapy under an agreement with the participants’ doctors, with the control group being men assigned to barbershops where the barbers only promoted lifestyle modification and physician visits. This intervention resulted in a mean BP drop of 27.0mmHg compared to the control group which fell by 9.3mmHg.
In a 1-year intervention based on costs for the LABBPS, on average, $2356 more per participant than the controls and was associated with a gain of 0.06 quality-adjusted life years (QALYs) over a 10-year horizon, according to Brandon Bellows, PharmD, MS, of Columbia University in New York City, and colleagues.
Thus, in computer simulations, the LABBPS intervention was associated with 10-year projected total healthcare costs averaging $42 717 per QALY gained, reported the researchers.
“One concern raised as a potential barrier to widespread LABBPS implementation is the specialty training of clinical pharmacists. In this analysis, the cost of specialty training and certification was included; the results suggest that long-term health benefits and avoided healthcare costs of the LABBPS offset these upfront training costs,” the researchers wrote.
The team reported that the cost effectiveness of the intervention could be increased under various various scenarios:
Only using generic drugs: $17 162 per QALY gained
Shortening intervention to 26 weeks: $18 300 per QALY gained
Implementing optimal savings from less time spent on intervention tasks, lower equipment costs, only using generics, and no participant incentive costs: intervention becomes dominant (both less expensive and more effective than control)
However, if pharmacists were less likely to intensify antihypertensive medications when systolic BP was ≥ 150 mm Hg, or if pharmacists took longer to get to the barbershops, the cost of the LABBPS intervention would exceed $50 000 per QALY gained.
“Hypertension care delivered by clinical pharmacists in Black barbershops is a highly cost-effective way to improve BP control in Black men,” the authors concluded.
The LABBPS has received praise for demonstrating that Black men with uncontrolled hypertension had better BP control after 6 months with barbershop visits by specialty pharmacists than with regular physician visits. Extending the intervention to 1 year did not change the results.
Researchers previously reported that a telemedicine component could bring down cost and maintain efficiency of the LABBPS program.
“Hypertension prevalence remains higher among non-Hispanic Black men than in any other racial or ethnic group in the US. Hypertension awareness and treatment have plateaued in the US since 2010, and Black men continue to have worse BP control and higher hypertension-related cardiovascular disease mortality rates compared with other groups,” the investigators wrote.
The researchers assumed that after the one-year intervention period, processes of hypertension care management returned to standard care, which was a major limitation of the study.
“These findings may also be somewhat limited in scope as a healthcare sector perspective was used, which only considers direct healthcare costs, rather than a societal perspective, which may include indirect costs such as improvements in productivity,” noted Bellows and co-authors. “Finally, cost-effectiveness estimated for the LABBPS may not be generalizable to other U.S. communities, as it was specific to Los Angeles County and was driven in part by the high underlying risk of cardiovascular disease in Black men.”
Journal information: Bryant KB, et al “Cost-effectiveness of hypertension treatment by pharmacists in black barbershops” Circulation 2021; DOI: 10.1161/CIRCULATIONAHA.120.051683.
A study conducted by the University of Campinas (UNICAMP) has found that adults can transmit the bacteria that cause periodontitis to their children, and even remain in the mouth when the children undergo various treatments.
Periodontitis, which is preceded by gingivitis, is a bacterially caused inflammation of the periodontium, the tissue supporting the teeth. It is characterised by swollen and bleeding gums and halitosis, and can result in loss of teeth in severe cases.
Should the microorganisms responsible for the disease enter the bloodstream, they may trigger other kinds of inflammation in the body. The disease can be treated by cleaning the pockets around the teeth by a dentist or dental hygienist and administration of anti-inflammatory drugs or antibiotics.
“The parents’ oral microbiome is a determinant of the subgingival microbial colonization of their children,” the article’s wrote in their conclusion, adding that “dysbiotic microbiota acquired by children of periodontitis patients at an early age are resilient to shift and the community structure is maintained even after controlling the hygiene status”.
According to the first author of the article, dental surgeon Mabelle de Freitas Monteiro, she and her group have been researching periodontitis for ten years, and have observed both parents with the disease and their children, and noted the impact on their health.
“If the findings are applied to day-to-day dental practice, the study can be said to help design more direct approaches. Knowing that periodontal disease may affect the patient’s family is an incentive to use preventive treatment, seek early diagnosis and mitigate complications,” said Monteiro, who was supported by FAPESP via two projects.
The principal investigator for both of these projects was Renato Corrêa Viana Casarin, a professor at UNICAMP’s Piracicaba Dental School (FOP), who is the last author of the article .
In Prof Casarin’s view, parents’s care of their children’s dental hygiene should start when they are still infants.
“This pioneering study compares parents with and without periodontitis,” said Prof Casarin. “In children of the former, we found subgingival bacterial colonization at a very early age. However, ‘inheriting’ the problem doesn’t mean a child is fated to develop the disease in adulthood. Hence the importance of keeping an eye open for the smallest signs and seeking specialized help.”
According to the latest national dental epidemiological survey from 2010, 18% of children aged 12 had never been to the dentist and 11.7% had experienced bleeding of the gums. Of those in the 15-19 age group, 13.6% had never visited a dental clinic. The planned 2020 survey was postponed due to COVID. According to the São Paulo State Department of Health’s latest oral health survey in 2019 revealed that 50.5% of adults aged 35-44 complained of toothache, bleeding gums and periodontitis.
In the FOP-UNICAMP study led by Casarin and Monteiro, the team colleclected samples of subgingival biofilm and plaque from 18 adults with a history of generalised aggressive (grade C) periodontitis, their children aged 6-12, and 18 orally healthy adults.
As well as a clinical analysis, the samples were also subjected to a microbiological analysis and genetic sequencing by Ohio State University researchers.
“Children of periodontitis parents were preferentially colonized by Filifactor alocis, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Streptococcus parasanguinis, Fusobacterium nucleatum and several species belonging to the genus Selenomonas even in the absence of periodontitis,” the article states. “These pathogens also emerged as robust discriminators of the microbial signatures of children of parents with periodontitis.”
Prof Casarin told Agência FAPESP that even with bacterial plaque control and vigorous brushing, children of people with the disease still had the bacteria in their mouths, whereas the effects of dental hygiene and prophylaxis were more significant in the children of healthy subjects.
“Because the parents had periodontitis, their children assumed this community with disease characteristics. They carried the bacterial information into their adult lives,” he said, adding that the analysis of bacterial colonisation indicated the transmission was more likely from the mother. The research group’s next step is working with pregnant women to prevent bacterial colonisation of their children’s mouths.
“We’ll treat the mothers during pregnancy, before the babies are born, and try to find out if it’s possible to prevent bacterial colonization from occurring,” Casarin said, adding that studies with patients will only go ahead when the pandemic is under control.
Journal information: Monteiro, M. F., et al. (2021) Parents with periodontitis impact the subgingival colonization of their offspring. Scientific Reports. doi.org/10.1038/s41598-020-80372-4.
Scientists have developed an injectable gel that serves as a biodegradable adhesive for various kinds of soft tissue injury.
Soft tissue tears are a common injury, and it is difficult for surgeons to secure the tissue back together, since stitches often do more harm than good. According to Dominique Pioletti, the head of the Laboratory of Biomechanical Orthopedics at EPFL’s School of Engineering, such surgeries often don’t produce the best results because the tissue doesn’t properly heal.
Tears in tissue such as cartilage and the cornea, often fail to heal properly, and tissue repair strategies may be suboptimal. For example, loose pieces of cartilage are often excised for symptomatic relief, but the remaining cartilage in articulating joints is placed under greater burden and generates faster.
A long-standing goal for researchers around the world has been the development of an adhesive for soft tissue that can withstand the natural stresses and strains within the human body. Now, Pioletti’s group has come up with a novel family of injectable biomaterials that can adhere to various forms of soft tissue. Their gel-based bioadhesives, can be used in a variety of injury-treatment applications. Like other hydrogels, this one has a high water content, 85%, and also has two key advantages: It is injectable anywhere in the human body, and it has high intrinsic adhesion without additional surface treatment. “What makes our hydrogel different is that it changes consistency while providing high adhesion to soft tissues,” said Peyman Karami, a postdoc at Pioletti’s lab who has developed the gel during his PhD. “It’s injected in a liquid form, but then sets when a light source is applied, enabling it to adhere to surrounding tissue.”
The hydrogel has an innovative design that allows its mechanical and adhesive properties to be tailored, making it an extremely versatile soft tissue glue that can be used throughout the human body.
To obtain these versatile properties in their hydrogel, the scientists took the base polymer and modified it with the compounds that play an important role in tissue adhesion. The first is known as Dopa and is derived from mussels. “Dopa is what lets mussels attach firmly to any kind of surface—organic or otherwise,” said Pioletti. The second is an amino acid that our bodies make naturally.
“The advantage of our hydrogel compounds is that, unlike some medical adhesives, they don’t interfere with the body’s chemical reactions, meaning our hydrogel is fully biocompatible,” said Karami.
The new hydrogel also possesses unique energy-dissipation characteristics that improve its adhesive capability. Karami added: “We had to achieve an adhesion mechanism for injectable hydrogels, through the resulting synergy between interfacial chemistry and hydrogel mechanical properties. The hydrogel is capable of dissipating the mechanical energy produced when the hydrogel deforms, so that it protects the interactions at the interface between the hydrogel and surrounding tissue.”
A further advantage of this hydrogel is that it can release drugs or cells to encourage tissue repair, which is especially beneficial for cartilage and other tissues that don’t regenerate on their own.
“Our in vitro tests showed that the hydrogel binds to many different kinds of tissue, including cartilage, meniscus, heart, liver, lung, kidney and cornea,” said Pioletti. “We’ve made a sort of universal hydrogel.”
The scientists have received a grant to research possible orthopedic applications of the gel, and hope to be able to release their innovation onto the market within the next five years.
Journal information: An intrinsically‐adhesive family of injectable and photo‐curable hydrogels with functional physicochemical performance for regenerative medicine, Macromolecular Rapid Communications, DOI :10.100 2/marc.202000660
