New gel inhibits growth of skin cancer cells - healing practice

Mycobacterial hydrogel effective against black skin cancer

A newly developed gel containing special bacteria is effective against cancer cells, according to a recent study. With the help of so-called mycobacterial hydrogel, the growth of black skin cancer cells could be inhibited. The research team also sees great potential in treating other types of cancer with solid tumors.

A working group from the University of Bern has developed a treatment option that activates the body's own defense system against melanoma. For this purpose, a special gel is applied to the tumor area. The mycobacteria contained in the gel inhibit tumor growth. The results were recently presented in the Journal for ImmunoTherapy of Cancer.

The gel activates the immune system against cancer using bacteria

As the Swiss researchers report, the bacterial gel was able to reduce tumor growth in mice with melanoma, prolong the animals' survival time and suppress the formation of metastases.

Black skin cancer is the most dangerous form of skin cancer

Black skin cancer (melanoma) is a malignant form of skin cancer. If diagnosed early, there is a good chance that the cancer can be completely eliminated. However, melanomas tend to spread to other organs, which is why the prognosis gets worse the longer the skin cancer goes unnoticed.

Immune treatments are improving

Over the past decade, first successes have been achieved with new immune therapies against melanoma. Here, the immune system is activated using so-called immune checkpoint inhibitors to fight cancer cells.

In some of the people affected, spectacular therapeutic successes could thus be obtained. In about half, however, the treatment does not work.

Building on the findings of the last ten years, the team led by Professor Mirjam Schenk from the Institute of Pathology at the University of Bern have now been able to significantly improve the approach in the form of the new hydrogel of mycobacteria.

Mycobacteria are already used in medicine

Live mycobacteria are already used for medical purposes. For example as a vaccine against tuberculosis. In a weakened form, the bacterium has already been approved for the treatment of metastatic melanoma of the skin.

So far, however, bacteria have been shown to be less effective in internal organ metastases. As the working group points out, treatment with live bacteria also carries some risk of complications.

The gel makes the bacteria more efficient

However, if the bacteria are embedded in a gel, they are much more effective than previous approaches, the researchers point out. The hydrogel is liquid at room temperature but becomes viscous at body temperature, forming a local deposit at the desired location. One application was enough for the mice.

The survival rate of animals has improved significantly

Survival time increased significantly in animals treated with the gel. At the same time, the formation of metastases in the lungs was suppressed. The gel is therefore a promising approach for people with melanoma who are at high risk of developing metastases.

Analysis of animal immune cells has shown that bacteria increase local activation of T cells, leading to a better immune response against melanoma cells.

An efficient and safe option

"Local application of the hydrogel loaded with BCG lysate is an effective and safe immunotherapeutic option to reduce the metastatic burden and prolong survival of patients with melanoma", summarizes the research director Schenk.

According to her, the results are not only of great importance in the context of immuno-oncology research in the treatment of melanoma, but also in other solid tumors. In the next step, the gel is to be tested in humans in a clinical study and compared with already approved therapies. (vb)

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This text corresponds to the requirements of the specialized medical literature, medical guidelines and current studies and has been verified by health professionals.


Graduate editor (FH) Volker Blasek


Wilhelm Sander Foundation: Use of mycobacterial hydrogel against melanoma (PDF, published: June 23, 2022), wilhelm-sander-stiftung.deMiela Kremenovic, Alfred A. Chan, Mirjam Schenk, et al. : BCG hydrogel promotes CTSS-mediated antigen processing and presentation, thereby suppressing metastasis and prolonging survival in melanoma; in: The Journal for ImmunoTherapy of Cancer (2022),

Important Note:
This article contains general advice only and should not be used for self-diagnosis or treatment. It cannot substitute a visit to the doctor.