Next-generation sutures are being developed to close wounds, detect inflammation, and deliver therapeutic drugs, further raising the bar in surgical recovery.
Engineers at the Massachusetts Institute of Technology (MIT) have created bioderived sutures to reduce patient discomfort and complications after surgery.
These smart sutures could help patients heal after bowel resection or other types of surgery.
The MIT researchers used pig tissue to create sutures that can carry sensors, drugs or cells and could also be adapted to heal wounds or surgical incisions elsewhere in the body.
Their work draws inspiration from catgut sutures that utilise collagen from cows, sheep and goats to form strong, naturally dissolving knots within around 90 days.
Former MIT postdocs Jung Seung Lee and Hyunjoon Kim are the lead authors of the paper published in Matter.
Giovanni Traverso is an associate professor of mechanical engineering at MIT, a gastroenterologist at Brigham and Women’s Hospital and the study's senior author.
Building on the concept of catgut, Traverso and his collaborators aimed to develop a tissue-derived suture material with enhanced properties such as toughness, absorbability and the advanced functionalities of sensing and drug delivery.
Such sutures could prove especially valuable for patients with Crohn’s disease, necessitating intestinal section removal due to scarring or inflammation-induced blockages.
The resealing of the remaining intestine ends following a procedure like this demands a secure seal to prevent hazardous leaks.
To mitigate this risk, the MIT team conceived the suture design that anchors the tissue and detects inflammation – a critical sign that the healed intestines are not recovering as expected.
The researchers crafted their innovative sutures from pig tissue, employing a ‘decellularisation’ process involving detergents to reduce the likelihood of triggering inflammation in the host tissue.
This process leaves a cell-free material called De-gut, encompassing structural proteins such as collagen and other biomolecules in the extracellular matrix around cells.
The team assessed its tensile strength after dehydrating and twisting the tissue into strands.
The results indicated comparable strength to commercially available catgut sutures, with the benefit of inducing significantly lower immune responses in surrounding tissue than traditional catgut.
Lee said: ‘Decellularised tissues have found extensive use in regenerative medicine due to their remarkable biofunctionality. We now propose an innovative platform for sensing and delivery using decellularised tissue that will unlock new applications for tissue-derived materials.’
The researchers progressed to enhance the suture material further by coating it with a hydrogel layer. Various cargo types could be embedded within this hydrogel, including microscopic particles capable of sensing inflammation, diverse drug compounds and even living cells.
The team designed microparticles coated with peptides released by inflammation-associated enzymes called MMPs for sensing.
These peptides can be detected through a simple urine test. Additionally, the researchers demonstrated the potential to carry drugs like dexamethasone and adalimumab—used for treating inflammatory bowel disease – via microparticles crafted from FDA-approved polymers like PLGA and PLA.
This method controls the drug release rate and can be adapted for other drug types like antibiotics or chemotherapy.
The versatility of these intelligent sutures extends to delivering therapeutic cells such as stem cells.
In exploring this application, the researchers incorporated stem cells engineered to express a fluorescent marker into the sutures, observing their viability for at least seven days after implantation in mice.
These cells could also produce vascular endothelial growth factor (VEGF), stimulating blood cell growth.
The team is now focused on comprehensively testing each potential application and scaling up suture manufacturing. They are also eager to investigate the feasibility of utilising these sutures in body regions beyond the gastrointestinal tract.
MIT engineers have designed tissue-derived smart sutures, pictured here, that can not only hold the tissue in place but also detect inflammation and release drugs. The sutures are coated with hydrogels that can be embedded with sensors, drugs, or cells that release therapeutic molecules. Image courtesy of the researchers
A new tool is changing how surgeons assess risks for adult heart surgery.
The Society of Thoracic Surgeons (STS) has harnessed advanced technology to help them better understand the risks involved in surgery.
The Operative Risk Calculator is a pioneering tool that draws on the extensive STS Adult Cardiac Surgery Database. It encompasses 97% of cardiac operations – or the treatment experiences of more than eight million patients across the States.
This upgraded calculator is primed to empower medical practitioners and usher in a new era of enhanced patient care by harnessing big data.
Mobile-friendly, it features a simplified, intuitive user design to improve physician-patient decision-making.
The heart of its innovation lies in its real-time risk estimation, facilitating timely and informed decisions for surgeons and multidisciplinary medical teams.
Powered by the latest nationwide data from the 2023 STS Adult Cardiac Surgery Database, the risk assessments are underpinned by resilient models that receive quarterly updates.
STS President, Dr Thomas MacGillivray, said: ‘This next-generation Operative Risk Calculator is a powerful, user-friendly tool that makes it easier for cardiothoracic surgical teams to assess risk and predict outcomes in real time for the vast majority of adult cardiac surgery procedures.’
The unveiling serves as a precursor to a series of upcoming enhancements to the STS National Database.
The expansion takes place in the coming months and is tailored to meet the day-to-day needs of surgeons, data managers and cardiothoracic care units.
User feedback informed the design of the new Risk Calculator and is also driving the development of other innovations to fully leverage the nearly 10 million cardiothoracic surgery procedures in the database.
By early 2024, its coverage looks to encompass more than 90% of all adult heart interventions, as it incorporates risk models for less frequently undertaken procedures.
Noteworthy features of this pioneering tool include:
The calculator generates real-time clinical summaries of simulated patients, complete with corresponding risk evaluations, streamlining integration with electronic health records.
The STS National Database incorporates data from around the US and spans 11 countries and is considered the benchmark for clinical registries chronicling patient outcomes in cardiothoracic surgery.
It unites data-driven precision with medical acumen to shape a future marked by improved patient outcomes and more informed medical decision-making.
The Adult Cardiac Surgery Operative Risk Calculator can be found here.
A research team has been recognised for developing histotripsy – a cutting-edge treatment that uses focused sound waves to disintegrate diseased tissue.
The pioneering technology employs precision-focused ultrasound waves to disrupt targeted tissue without resorting to thermal ablation techniques.
And as histotripsy emerges as a viable non-invasive alternative to conventional surgical interventions, the researchers’ work has been rewarded as they scooped this year’s prestigious Distinguished University Innovator Award.
The award recognises the outstanding contributions of University of Michigan faculty members who have nurtured transformative concepts, processes, or technologies and guided their journey to the broader market for societal benefit.
The innovative team from the University of Michigan’s College of Engineering and Medical School includes:
Mary-Ann Mycek, interim chair and professor of biomedical engineering, commended the collaborative team’s remarkable achievements and highlighted how their contribution has taken the innovation towards clinical translation and commercialisation.
A start-up enterprise called HistoSonics was established in 2010 and dedicated to steering research commercialisation initiatives.
While minimally invasive and non-invasive techniques have become standard practice in clinical settings, they have limitations.
HistoSonics has accomplished the seemingly unattainable feat of using sound wave energy to obliterate diseased tissue.
Zhen Xu expressed gratitude for the support from the University of Michigan during the journey of inventing and developing histotripsy.
She said: ‘Science’s most thrilling aspect lies in converting the impossible into reality. Our team’s achievement of providing a painless, non-toxic method to obliterate diseased tissue through sound wave energy is truly remarkable.’
She sees further applications for histotripsy across many medical domains, including stroke, neurological diseases, cardiovascular disorders and skin ailments.
Earlier this year, a ground-breaking milestone was achieved as 73-year-old Anthony Harris became the world's first cancer patient to undergo kidney tumour ‘removal’ using histotripsy.
Leeds Teaching Hospitals NHS Trust and HistoSonics jointly announced the momentous achievement that marked the inaugural treatment in the CAIN Trial, a Phase I prospective, multi-centre study designed to evaluate the safety and technical success of the histotripsy system in targeting and obliterating primary solid renal tumours in a completely non-invasive manner.
Example of HistoSonics technology targeting kidney tissue to be destroyed in a non-invasive histotripsy procedure.