{"id":17171,"date":"2026-04-27T19:55:39","date_gmt":"2026-04-27T15:55:39","guid":{"rendered":"https:\/\/medscriptum.org\/?p=17171"},"modified":"2026-04-28T15:29:05","modified_gmt":"2026-04-28T11:29:05","slug":"living-motors-from-your-own-tissue-the-biohybrid-future-of-organ-repair","status":"publish","type":"post","link":"https:\/\/medscriptum.org\/en\/living-motors-from-your-own-tissue-the-biohybrid-future-of-organ-repair\/","title":{"rendered":"Living Motors from Your Own Tissue: The Biohybrid Future of Organ Repair"},"content":{"rendered":"

For decades, neuroscience held a fairly firm assumption: sensory nerves could not form functional motor synapses with skeletal muscle. That idea quietly shaped the limits of what regenerative medicine was thought to be capable of. Researchers at <\/span>MIT<\/span><\/a> – Hyungeun Song, Guillermo Herrera-Arcos, and Hugh Herr – have now challenged that view, showing that regenerating sensory nerves, guided by molecular signals from muscle, can in fact build new cholinergic neuromuscular junctions from scratch.<\/span><\/p>\n

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MIT researchers (from left to right) Hyungeun Song, Guillermo Herrera-Arcos, and Hugh Herr have developed the first \u201cliving\u201d implant that uses rewired sensory nerves to revive paralyzed organs. Photo: Jim Day, MIT Media Lab<\/figcaption><\/figure>\n

This discovery is the basis of the Myoneural Actuator (MNA), a fully biological implant made from the body\u2019s own redundant tissue and designed to provide fatigue-resistant actuation for paralyzed organs. But perhaps more striking than the device itself is what the biology is revealing. During regeneration, skeletal muscle appears to actively guide sensory nerves, helping them assemble synaptic machinery that was once thought to be the exclusive domain of motor neurons. In other words, the tissue doesn\u2019t just respond to nerve input – it helps define how that connection is built.<\/span><\/p>\n

What emerges is a new way of thinking about implants: not as foreign objects placed into the body, but as living interfaces made from the body itself, controlled through simple cuff electrodes, and potentially capable of functioning for decades while closely matching native organ performance.<\/span><\/p>\n

In this interview, Guillermo Herrera-Arcos reflects on what it means to work with biology as a design medium rather than as a constraint. He discusses the practical realities of bringing MNAs toward the clinic, the questions that arise when living tissue is placed under computational control, and how this line of work is reshaping how we think about treating organ failure altogether.<\/span><\/p>\n

At the intersection of biology, engineering, and computation, your Media Lab is developing biohybrid approaches such as the MNA study, which aims to restore function to paralyzed organs using a patient\u2019s own tissue. What makes you see biohybrid systems as a turning point in medicine, and what about their potential excites you most?<\/i><\/b><\/p>\n

For centuries, we’ve engineered mostly with synthetic materials, often trying to fit them into the human body. But we’re still nowhere near matching the incredible complexity and sophistication of biology, something evolution has fine-tuned over millions of years. Take left ventricular assist devices (LVADs): they are remarkable feats of engineering, yet they require highly invasive integration – a mechanical pump connected to the heart and powered by external batteries through a cable that exits the body.<\/span><\/p>\n

Biohybrid design takes a different approach by starting with biology itself and working with it rather than around it. When we began developing the myoneural actuator, we asked a simple question: what is the best actuator we could use? The answer was straightforward – skeletal muscle. But that raised two key challenges: how to remove voluntary control and how to ensure the system could function reliably over time. Once again, the solution came from biology. Peripheral nerves are highly regenerative, so we used a sensory nerve to decouple the muscle from conscious control. This also helped reduce fatigue, since sensory axons are better suited for sustained, fatigue-resistant stimulation. By tapping into the natural adaptability of neuromuscular tissue, we were able to create what is essentially a \u201cliving\u201d motor inside the body.<\/span><\/p>\n

Biohybrid design allows us to imagine systems with incredible capabilities that would otherwise be extremely complex to realize using purely synthetics. As we keep discovering biological mechanisms, we will keep expanding a toolkit that bioengineers and surgeons can use to repurpose and heal the human body.<\/span><\/p>\n

The finding that sensory nerves can form cholinergic synapses with skeletal muscle is quite surprising. What stood out to you most about this regenerative capacity, and how might it change our understanding of plasticity in the peripheral nervous system?<\/i><\/b><\/p>\n

Absolutely! The most surprising thing was when we electrically stimulated the muscle through the sensory nerve, the contraction looked essentially identical to a natural one. That immediately made us wonder whether there might be functional neuromuscular junction machinery connecting the sensory axons to the muscle fibers – and, to our surprise, we found that there was.<\/span><\/p>\n

Stepping back, this points to a much higher level of plasticity in the peripheral nervous system than we usually assume. It suggests that reinnervation may bring the neuromuscular system into a more embryonic-like state, where – likely influenced by signals from the muscle – neurons can build the synaptic machinery needed to form a cholinergic connection. We still have more work to do to fully understand the mechanism, but it raises an intriguing possibility: that through reinnervation and similar processes, we might be able to nudge cells into a regenerative state, giving us more flexibility to design new interfaces and, potentially, new approaches to regenerative medicine in the periphery.<\/span><\/p>\n

Why did your team choose direct muscle neurotization for sensory reinnervation, and what does this approach reveal about the body\u2019s ability to repurpose neural pathways?<\/i><\/b><\/p>\n

We chose direct muscle neurotization partly because it has been used before in studies focused on sensory protection, sometimes referred to as \u201cbabysitting.\u201d It\u2019s also a more straightforward procedure compared to end-to-end nerve repair. What\u2019s interesting is what this approach revealed: during regeneration, the target tissue – in this case, skeletal muscle – may actually guide the process. It seems to send signals through the nerve that help determine what kind of connection needs to be formed. In other words, the muscle isn\u2019t just a passive recipient; it may actively influence how neurons build the necessary molecular machinery, highlighting a surprisingly adaptable and responsive quality in the body\u2019s neural systems.<\/span><\/p>\n

MNAs use routine nerve grafts and cuff electrodes. What do you see as the biggest regulatory or surgical hurdle for first-in-human implantation, and how do you plan to address it?<\/i><\/b><\/p>\n

We believe that, as long as we can demonstrate that the myoneural actuator is beneficial in specific conditions, the regulatory pathway should be relatively smooth. The main challenge is not any single component in isolation, but the integration of the full system – showing that the myoneural actuator, when chronically interfaced with an organ such as the heart, delivers meaningful and sustained benefit to patients.<\/span><\/p>\n

Several practical considerations come into play. One is the interface between the myoneural actuator and the target organ. We need to account for the electrical and mechanical properties of skeletal muscle and ensure they do not have unintended effects on the organ being actuated. Where necessary, this can be managed by introducing an insulating layer between the actuator and the tissue. Another consideration is surgical feasibility – specifically, the availability of suitable muscles and nearby nerves to construct the actuator. In many cases, redundant or functionally dispensable muscles, along with adjacent sensory nerves, can be used to build the system in a clinically practical way.<\/span><\/p>\n

For spinal cord injury patients with neurogenic bladder dysfunction, how close are MNAs to human trials, and which organ would you prioritize first – bladder, intestine, or diaphragm – and why?<\/i><\/b><\/p>\n

We see the bladder as a particularly strong starting point. Restoring bladder control is a major priority for people living with spinal cord injury, and it\u2019s one of those functions where even partial restoration could make a real difference in daily life. In this setting, a myoneural actuator wrapped around the bladder and placed under voluntary control could, in principle, allow patients to empty the bladder on demand.<\/span><\/p>\n

The key step would be showing that this interface can remain stable over long periods, and that bladder function can be reliably and safely modulated over time. Looking beyond the bladder, we also think there are important opportunities in other organs. In particular, a biohybrid approach to cardiac support – essentially using living tissue to help mechanically assist the heart – could have a major clinical impact.<\/span><\/p>\n

Unlike mechanical pumps or transplants, MNAs avoid rejection by using the patient\u2019s own tissue. How do you plan to source muscle and nerve tissue in patients without amputation leftovers?<\/i><\/b><\/p>\n

For muscle, we would rely on what are often considered \u201credundant\u201d or functionally less critical muscles. In reconstructive surgery, muscles such as the latissimus dorsi in the back, rectus abdominis in the abdomen, and pectoralis major in the chest are already routinely used as donor tissues. One advantage of the myoneural actuator is that it doesn\u2019t rely on preserving the original blood and nerve supply, which makes it possible to safely repurpose these muscles from different parts of the body.<\/span><\/p>\n

For the nerve component, we would use sensory nerves that are already located near the target organ. These nearby nerves can then be integrated into the system to provide the interface needed to control the actuator.<\/span><\/p>\n

MNAs enable computer-mediated control of autonomic functions such as urination or breathing. What ethical guardrails should govern who controls these \u201cliving motors\u201d?<\/i><\/b><\/p>\n

We think of these actuators as medical therapies first and foremost, and in that sense they should be guided by the same ethical and regulatory frameworks that already exist for implantable devices like LVADs and pacemakers. The main difference here is that the \u201cmotor\u201d is biological rather than mechanical, which may improve integration and performance, but doesn\u2019t change its role as a therapeutic tool.<\/span><\/p>\n

In terms of control, the core principle should be straightforward: the system\u2019s primary job is to safely and reliably deliver the intended function. Beyond that, there is room for flexibility. In some clinical settings, it may make sense for control to be shared between the device, the patient, and even caregivers.<\/span><\/p>\n

You describe this as a \u201cnew genre of medicine where tissue becomes hardware.\u201d Where do you see biohybrid systems in 10 years – becoming routine for organ failure, or extending into augmentation of healthy organs?<\/i><\/b>
\n<\/span><\/i><\/p>\n

We think biohybrid systems could become a standard way of treating organ failure. Paired with new approaches for repairing or replacing damaged tissue, they could really change how we think about late-stage disease. The goal is to move toward implantable systems that are seamlessly integrated with the body, can last for decades, and are able to restore – or match – the function of the tissue they replace.<\/span><\/p>\n



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For decades, neuroscience held a fairly firm assumption: sensory nerves could not form functional motor synapses with skeletal muscle. That idea quietly shaped the limits of what regenerative medicine was thought to be capable of. Researchers at MIT – Hyungeun Song, Guillermo Herrera-Arcos, and Hugh Herr – have now challenged that view, showing that regenerating […]<\/p>\n","protected":false},"author":5,"featured_media":17172,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1653,1659,1703],"tags":[5270,4047,5269],"class_list":["post-17171","post","type-post","status-publish","format-standard","has-post-thumbnail","category-interview","category-technologies","category-tematicum","tag-biohybrid","tag-mit","tag-mna"],"acf":[],"_links":{"self":[{"href":"https:\/\/medscriptum.org\/en\/wp-json\/wp\/v2\/posts\/17171","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/medscriptum.org\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/medscriptum.org\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/medscriptum.org\/en\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/medscriptum.org\/en\/wp-json\/wp\/v2\/comments?post=17171"}],"version-history":[{"count":4,"href":"https:\/\/medscriptum.org\/en\/wp-json\/wp\/v2\/posts\/17171\/revisions"}],"predecessor-version":[{"id":17262,"href":"https:\/\/medscriptum.org\/en\/wp-json\/wp\/v2\/posts\/17171\/revisions\/17262"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/medscriptum.org\/en\/wp-json\/wp\/v2\/media\/17172"}],"wp:attachment":[{"href":"https:\/\/medscriptum.org\/en\/wp-json\/wp\/v2\/media?parent=17171"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/medscriptum.org\/en\/wp-json\/wp\/v2\/categories?post=17171"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/medscriptum.org\/en\/wp-json\/wp\/v2\/tags?post=17171"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}