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This article is supported by SIDA

[DAR ES SALAAM, SciDev.Net] Tanzanian scientists say finding gene variants that predict a sickle cell patient’s response to drugs should pave the way for DNA testing before treatment, to improve outcomes.

In their research published April in Nature, researchers at the Muhimbili University of Health and Allied Sciences (MUHAS) confirm a long-held hypothesis that a patient’s genes influence whether the drug hydroxyurea works for them.

Around a third of sickle cell patients don’t respond well to hydroxyurea, even though it’s currently the only approved drug that can significantly improve their quality of life, according to Deogratius Soka, director of the Tanzania Sickle Cell Disease Alliance, who was not involved in the study.

Sickle cell disease affects around 120 million people globally, with Africa carrying 66 per cent of the burden, according to the World Health Organization.

The inherited condition causes red blood cells to become hard, sticky, and C-shaped, triggering severe pain, organ damage, and shortened life expectancy.

Hydroxyurea helps prevent red blood cells from sickling, but many patients gain little or no benefit, explains Soka.

Being able to identify that group early, he adds, would be “a huge leap forward in improving patient care”.

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Mohamed Zahir Alimohamed, a molecular geneticist and lecturer at MUHAS and co-author of the study, said the findings could be used to justify policy changes to allow for testing before administering hydroxyurea in the future.

He explained that in Tanzania, hydroxyurea is currently prescribed based on clinical criteria, such as symptoms, frequency of pain crises, and blood test results, rather than genetic testing.

“We usually monitor patients for three to six months to see if they are responding,” he said.

“That means those who do not respond can spend months on a drug that isn’t helping them.”

Lead researcher Collin Nzunda, a molecular biologist at MUHAS, says genetic testing before treatment could “boost precision medicine” in Africa by tailoring care to each patient’s genetic profile, a practice already common in wealthier countries.

The study analysed the DNA of 148 Tanzanian sickle cell patients to understand why some respond well to hydroxyurea while others do not. It found that variations in several genes were linked to treatment response.

Co-author Siana Nkya, a senior lecturer at MUHAS, says these genetic markers can predict how quickly a patient’s body processes the drug. “Someone who processes the drug slowly would need a smaller dose to avoid side effects, and vice versa,” she explains.

Nkya adds that in some cases testing could help doctors skip hydroxyurea altogether in favour of other interventions such as bone marrow transplants, new drugs in development, or even gene therapy.

She argues that in countries such as Tanzania, where treatment costs are a major barrier, this approach could have far-reaching benefits.

“It prevents unnecessary side effects, helps doctors make better treatment choices, and ultimately saves money for patients, their families, and the entire health system,” she says.

While the research is promising, the team cautions that it is still preliminary, involving a relatively small sample size.

Larger, longer-term studies are needed to validate the results before genetic testing can be rolled out nationwide.

Soka also stresses that prevention must remain a priority alongside personalised treatment. “The take-home message is therefore primary prevention, premarital screening remains the most effective means of breaking the cycle of sickle cell disease,” he tells SciDev.Net.

This article was produced by SciDev.Net’s Sub-Saharan Africa English desk.

The article is supported by Swedish International Development Cooperation Agency (SIDA, a Swedish government agency responsible for administering Sweden’s official development assistance).

An artificial intelligence model designed new antibiotics to fight gonorrhea and mRSA superbugs.

The overuse of antibiotics can create resistance, when the drugs kill off all but those bacteria most capable of surviving the treatment. It has led to the rise of some bugs that are all but impossible to treat with existing antibiotics, raising fears that modern medicine and surgery — reliant on antibiotics — could collapse, given that few new antibiotics are produced.

The new drugs were designed atom-by-atom using AI, and while they are a long way from the clinic, researchers hoped they could create a new pipeline for drugs. AI is rapidly transforming drug development and biology, allowing scientists to better predict how molecules behave in the body.

Large burns are often treated by transplanting a thin layer from the skin’s surface – the epidermis – which is mainly composed of a single cell type. However, replacing only  this layer results in severe scarring.

Under the epidermis there is a thicker and more advanced layer of skin called the dermis. It has blood vessels, nerves, hair follicles and other structures necessary for skin function and elasticity. However, transplanting only the dermis is rarely an option, as the procedure leaves a wound as large as the wound that needs to be healed.

The trick is to create new skin that does not become scar tissue, but a functioning dermis.

Transplanting the building blocks of dermis

“The dermis is so complicated that we can’t grow it in a lab. We don’t even know what all its components are. That’s why we, and many others, think that we could possibly transplant the building blocks and then let the body make the dermis itself,” says Johan Junker, researcher at the Swedish Center for Disaster Medicine and Traumatology, who led the study published in Advanced Healthcare Materials.   

The most common cell type in the dermis – the connective tissue cell or fibroblast – is easy to remove from the body and grow in a lab. The connective tissue cells can also develop into more specialised cell types. In the study, researchers provided a scaffold by growing the cells on tiny, porous beads of gelatine – a substance similar to skin collagen. However, a liquid containing these beads will not stay in place when poured onto a wound.

‘Skin in a syringe’

The researchers’ solved this problem by mixing the gelatine beads with a gel consisting of another body-specific substance – hyaluronic acid. The beads and gel are then mixed using a process known as click chemistry. The result is a gel that can effectively be called ‘skin in a syringe.’

“The gel has a special feature that means that it becomes liquid when exposed to light pressure. You can use a syringe to apply it to a wound, for example, and once applied it becomes gel-like again. This also makes it possible to 3D print the gel with the cells in it,” says Daniel Aili, professor of molecular physics at Linköping University.

Promising results in mice

In the current study, the researchers 3D-printed small pucks and implanted them under the skin of mice. The results suggest this technology could  grow the patient’s own cells from a minimal skin biopsy – which can then be 3D-printed into a graft and applied to the wound.

“We see that the cells survive and it’s clear that they produce different substances that are needed to create new dermis. In addition, blood vessels are formed in the grafts, which is important for the tissue to survive in the body. We find this material very promising,” says Johan Junker.

Tackling the blood vessel limitation

Blood vessels are essential for many applications of engineered tissue-like materials. Scientists can grow cells in three-dimensional structures to create organoids, but these models lack the vessels needed to transport oxygen and nutrients to the cells. As a result, their size is limited –  cells at the centre die once deprived of oxygen and nutrients.

The LiU researchers may be closer to solving this problem, describing a method for making threads from materials composed of 98 percent water, known as hydrogels.    

“The hydrogel threads become quite elastic, so we can tie knots on them. We also show that they can be formed into mini tubes, which we can pump fluid through or have blood vessel cells grow in,” says Daniel Aili.

The mini-tubes or the ‘perfusable channels’, as the researchers call them, enable the development of blood vessels in organoids.

Going forward

The development of “skin in a syringe” marks an important step toward effective burn treatments that restore both the form and function of damaged skin. By combining patient-derived cells with advanced biomaterials, researchers have created a 3D-printable gel that supports dermis formation and blood vessel growth – two key factors in long-term healing. Beyond burn care, the technology’s potential to overcome the blood vessel limitations could accelerate progress in organoid research and other regenerative medicine applications, bringing science closer to creating fully functional, lab-grown tissues.