Can printed ‘skin’ help to heal burns without scars?

Inks created with a patient’s own cells might one day help the body regrow tissues

Cells suspended in a water-based gel make up the “ink” in this 3D printer.
Source: WAKE FOREST INSTITUTE FOR REGENERATIVE MEDICINE

Ahand touches a scalding hot plate, sharp pain erupts and immediately, the body gets to work. Damaged cells send out distress signals; immune cells rush in. As inflammation subsides, a coordinated repair process begins. Eventually, collagen fibers aligned in tight parallel rows will replace much of the damaged tissue. The wound heals, but it does not resemble normal skin.

For a small burn or cut, a scar is a small price to pay for rapid healing that mitigates the risk of infection. But in larger burn wounds, scarring can be devastating.

Each year, 11 million people require hospital care for burns. Long after the wounds have healed, scarring can cause complications. Unlike the random, basket-weave pattern that makes normal skin flexible and resilient, scar tissue tightens as it heals and, once mature, grows more slowly than surrounding skin. This can hinder movement and, in children with extensive burns, interfere with normal growth and development. Severe scars often lack hair follicles, sweat glands and nerve endings, reducing the ability to experience touch and to regulate body temperature.

Normal skin contains collagen fibers that grow in a random basket-weave pattern shown here, while in scar tissue collagen fibers typically grow parallel to each other.
Source: STEVE GSCHMEISSNER / SCIENCE SOURCE

Scientists have long tried to develop ways to nudge the body to build healthy tissue instead of defaulting to emergency repair. In recent years, 3D bioprinting technology has emerged as one of the most promising approaches. By depositing patients’ own, pre-cultured skin cells suspended in an ink-like gel, these printers can create personalized skin substitutes, kickstarting the regeneration process. While it is early days, the technology is coming closer to clinical reality.

The key is accessing the body’s ability to rebuild, says wound healing researcher Johan Junker of Linköping University in Sweden. Our bodies, he says, “have been practicing this for millions of years, and we do it constantly, because our skin and every tissue in our body, more or less, always turns over. So why not just provide as good a set of building blocks as we can and then let nature do its thing?”

Achieving lasting remission for HIV

People infected with HIV must take antiretroviral drugs for life. But promising trials using engineered antibodies suggest that ‘functional cures’ may be in reach.

A digital illustration of an HIV-infected T cell. Once infected, the immune cell is hijacked by the virus to produce and release many new viral particles before dying. As more T-cells are destroyed, the immune system is progressively weakened.

Source: KATERYNA KON / SHUTTERSTOCK

Around the world, some 40 million people are living with HIV. And though progress in treatment means the infection isn’t the death sentence it once was, researchers have never been able to bring about a cure. Instead, HIV-positive people must take a cocktail of antiretroviral drugs for the rest of their lives.

But in 2025, researchers reported a breakthrough that suggests that a “functional” cure for HIV — a way to keep HIV under control long-term without constant treatment — may indeed be possible. In two independent trials using infusions of engineered antibodies, some participants remained healthy without taking antiretrovirals, long after the interventions ended.

In one of the trials — the FRESH trial, led by virologist Thumbi Ndung’u of the University of KwaZulu-Natal and the Africa Health Research Institute in South Africa — four of 20 participants maintained undetectable levels of HIV for a median of 1.5 years without taking antiretrovirals. In the other, the RIO trial set in the United Kingdom and Denmark and led by Sarah Fidler, a clinical doctor and HIV research expert at Imperial College London, six of 34 HIV-positive participants have maintained viral control for at least two years.

These landmark proof-of-concept trials show that the immune system can be harnessed to fight HIV. Researchers are now looking to conduct larger, more representative trials to see whether antibodies can be optimized to work for more people.

“I do think that this kind of treatment has the opportunity to really shift the dial,” Fidler says, “because they are long-acting drugs” — with effects that can persist even after they’re no longer in the body. “So far, we haven’t seen anything that works like that.”

People with HIV can live long, healthy lives if they take antiretrovirals. But their lifespans are still generally shorter than those of people without the virus. And for many, daily pills or even the newer, bimonthly injections present significant financial, practical and social challenges, including stigma. “Probably for the last about 15 or 20 years, there’s been this real push to go, ‘How can we do better?’” says Fidler.