Tag: Medicine

Research team(Left to right): Eilam Yeini, Prof. Satchi-Fainaro and Lena Neufeld

The 3D print of glioblastoma – the deadliest type of brain cancer – is printed from human glioblastoma tissues containing all components of the malignant tumor

Researchers: the breakthrough will enable much faster prediction of best treatments for patients, accelerate the development of new drugs and discovery of new druggable targets

A scientific achievement for researchers at Tel Aviv University: printing an entire active and viable glioblastoma tumor using a 3D printer. The 3D-bioprinted tumor includes a complex system of blood vessel-like tubes through which blood cells and drugs can flow, simulating a real tumor.

Illustration.
Credit: Veronica Hughes, PhD of STEAM visuals

The study was led by Prof. Ronit Satchi-Fainaro, Sackler Faculty of Medicine and Sagol School of Neuroscience, Director of the Cancer Biology Research Center, Head of the Cancer Research and Nanomedicine Laboratory and Director of the Morris Kahn 3D-BioPrinting for Cancer Research Initiative, at Tel Aviv University.

The new technology was developed by PhD student Lena Neufeld, together with other researchers at Prof. Satchi-Fainaro’s laboratory:  Eilam Yeini, Noa Reisman, Yael Shtilerman, Dr. Dikla Ben-Shushan, Sabina Pozzi, Dr. Galia Tiram, Dr. Anat Eldar-Boock and Dr. Shiran Farber.  

The 3D-bioprinted models are based on samples from patients, taken directly from operating rooms at the Tel Aviv Sourasky Medical Center. The new study’s results were published today in the prestigious journal Science Advances.

“Glioblastoma is the most lethal cancer of the central nervous system, accounting for most brain malignancies,” says Prof. Satchi-Fainaro. “In a previous study, we identified a protein called P-Selectin, produced when glioblastoma cancer cells encounter microglia – cells of the brain’s immune system. We found that this protein is responsible for a failure in the microglia, causing them to support rather than attack the deadly cancer cells, helping the cancer spread. However, we identified the protein in tumors removed during surgery, but not in glioblastoma cells grown on 2D plastic petri dishes in our lab. The reason is that cancer, like all tissues, behaves very differently on a plastic surface than it does in the human body. Approximately 90% of all experimental drugs fail at the clinical stage because the success achieved in the lab is not reproduced in patients.”

Prof. Ronit Satchi-Fainaro

To address this problem, the research team led by Prof. Satchi-Fainaro and PhD student Lena Neufeld, recipient of the prestigious Dan David Fellowship, created the first 3D-bioprinted model of a glioblastoma tumor, which includes 3D cancer tissue surrounded by extracellular matrix, which communicates with its microenvironment via functional blood vessels.

Microscopic image of the 3D-bioprinted glioblastoma model. The bioprinted blood vessels are covered with endothelial cells (red) and pericytes (cyan). The blood vessels are surrounded with a brain-mimicking tissue composed of gliblastoma cells (blue) and the brain microenvironment cells (green). Different drugs or cells can be perfused through the 3D-bioprinted blood vessels to test their effect on the tumor tissue

“It’s not only the cancer cells,” explains Prof. Satchi-Fainaro. “It’s also the cells of the microenvironment in the brain; the astrocytes, microglia and blood vessels connected to a microfluidic system – namely a system enabling us to deliver substances like blood cells and drugs to the tumor replica. Each model is printed in a bioreactor we have designed in the lab, using a hydrogel sampled and reproduced from the extracellular matrix taken from the patient, thereby simulating the tissue itself. The physical and mechanical properties of the brain are different from those of other organs, like the skin, breast, or bone. Breast tissue consists mostly of fat, bone tissue is mostly calcium; each tissue has its own properties, which affect the behavior of cancer cells and how they respond to medications. Growing all types of cancer on identical plastic surfaces is not an optimal simulation of the clinical setting.”

After successfully printing the 3D tumor, Prof. Satchi-Fainaro and her colleagues demonstrated that unlike cancer cells growing on petri dishes, the 3D-bioprinted model has the potential to be effective for rapid, robust, and reproducible prediction of the most suitable treatment for a specific patient.

“We proved that our 3D model is better suited for prediction of treatment efficacy, target discovery and drug development in three different ways.

First, we tested a substance that inhibited the protein we had recently discovered, P-Selectin, in glioblastoma cell cultures grown on 2D petri dishes, and found no difference in cell division and migration between the treated cells and the control cells which received no treatment. In contrast, in both animal models and in the 3D-bioprinted models, we were able to delay the growth and invasion of glioblastoma by blocking the P-Selectin protein.

This experiment showed us why potentially effective drugs rarely reach the clinic simply because they fail tests in 2D models, and vice versa: why drugs considered a phenomenal success in the lab, ultimately fail in clinical trials. In addition, collaborating with the lab of Dr. Asaf Madi of the Department of Pathology at TAU’s Faculty of Medicine, we conducted genetic sequencing of the cancer cells grown in the 3D-bioprinted model, and compared them to both cancer cells grown on 2D plastic and cancer cells taken from patients.

Thus, we demonstrated a much greater resemblance between the 3D-bioprinted tumors and patient-derived glioblastoma cells grown together with brain stromal cells in their natural environment. Through time, the cancer cells grown on plastic changed considerably, finally losing any resemblance to the cancer cells in the patient’s brain tumor sample.

The third proof was obtained by measuring the tumor growth rate. Glioblastoma is an aggressive disease partially because it is unpredictable: when the heterogeneous cancer cells are injected separately into model animals, the cancer will remain dormant in some, while in others, an active tumor will develop rapidly. This makes sense because we, as humans, can die peacefully of old age without ever knowing we have harbored such dormant tumors. On the dish in the lab, however, all tumors grow at the same rate and spread in the same rate. In our 3D-bioprinted tumor, the heterogeneity is maintained and development is similar to the broad spectrum that we see in patients or animal models.”

According to Prof. Satchi-Fainaro, this innovative approach will also enable the development of new drugs, as well as discovery of new drug targets – at a much faster rate than today. Hopefully, in the future, this technology will facilitate personalized medicine for patients.

“If we take a sample from a patient’s tissue, together with its extracellular matrix, we can 3D-bioprint from this sample 100 tiny tumors and test many different drugs in various combinations to discover the optimal treatment for this specific tumor. Alternately, we can test numerous compounds on a 3D-bioprinted tumor and decide which is most promising for further development and investment as a potential drug.

But perhaps the most exciting aspect is finding novel druggable target proteins and genes in cancer cells – a very difficult task when the tumor is inside the brain of a human patient or model animal. Our innovation gives us unprecedented access, with no time limits, to 3D tumors mimicking better the clinical scenario, enabling optimal investigation.”

Illustration for demonstration of 3D printing of a tumor in a brain Microenvironment according to a computed 3D model

The study was funded by the Morris Kahn Foundation, European Research Council (ERC), Israel Cancer Research Fund (ICRF), the Israel Cancer Association and Israel Science Foundation (ISF), and Check Point Software Technologies LTD.

Prof. Noam Shomron, Head of the Computational Genomics Laboratory at the Sackler Faculty of Medicine and a member of the Edmond J. Safra Center for Bioinformatics

A joint study conducted by researchers from Tel Aviv University and the Shamir Medical Center (Asaf Harofe) examined the level of antibodies in over 26,000 blood samples taken from COVID-19 convalescents, as well as vaccinated and unvaccinated individuals. The serological results indicate that the level of antibodies changes according to age groups, gender, symptoms, and time elapsed since vaccination. The study was published in Medrxiv.

A difference was found between vaccinated women and men, in the concentration of antibodies in the blood relative to both age and gender. In women, the level of antibodies begins to rise from the age of 51, and is higher than the levels found in men of similar age. This phenomenon may be related change in levels of the estrogen hormone, observed around this age, which affects the immune system. In men, a rise in antibody levels is seen at an earlier age, starting around 35. This may be related to changes in levels of the male sex hormone testosterone, and the effect on the immune system.

In young adults, a high concentration of antibodies is usually the result of a strong immune response, while in older people it typically indicates overreaction of the immune system associated with severe illness.

Dr. Adina Bar Chaim from the Shamir Medical Center

Main trends and findings:

1. The immune response of individuals who have received two doses of the vaccine is much stronger than that of people who have recovered from COVID-19. In fact, the level of antibodies found in the blood of vaccinated persons was 4 times higher than that found in convalescents.
2. A difference was found between convalescent males and females – in antibody concentration in the blood relative to both age and gender. In women, the concentration begins to rise from the age of 51, and it is higher than the levels found in men of similar age. This phenomenon may be related to the change in levels of the estrogen hormone, observed around this age, which affects the immune system. In men, a rise in antibody levels is seen at an earlier age, starting around 35. This may be related to changes in levels of the male sex hormone testosterone, and its effect on the immune system.

In young adults, a high concentration of antibodies is usually the result of a strong immune response, while in older people it usually indicates overreaction of the immune system associated with severe illness.

3. In general, young adults were found to have a higher level of antibodies sustained for a longer period of time compared to older vaccinated persons. A decrease of tens of percent was observed over time between the younger and very old age groups.

Conclusion: Further research is required in order to obtain an in-depth understanding of the immune system’s response to COVID-19, to recovery from the disease, and to the vaccine. We hope that in the future we will be able to supply a reliable measure for the effectiveness of vaccination, correlated with age, gender and symptoms.

The study was conducted by Tel Aviv University’s Prof. Noam Shomron, Head of the Computational Genomics Laboratory at the Sackler Faculty of Medicine and a member of the Edmond J. Safra Center for Bioinformatics and Dr. Adina Bar Chaim from the Shamir Medical Center. The data were collected by Dr. Ramzia Abu Hamad from the Shamir Medical Center, and analysis was conducted by Guy Shapira, a PhD student at Prof. Shomron’s laboratory.

• Researchers have developed a sensor that can be implanted anywhere in the body, for example under the tip of a severed finger; the sensor connects to another nerve that functions properly and restores tactile sensation to the injured nerve.
• This unique development is biocompatible (“human-body friendly”) and does not require electricity, wires, or batteries.

Tel Aviv University’s new and groundbreaking technology inspires hope among people who have lost their sense of touch in the nerves of a limb following amputation or injury. The technology involves a tiny sensor that is implanted in the nerve of the injured limb, for example in the finger, and is connected directly to a healthy nerve. Each time the limb touches an object, the sensor is activated and conducts an electric current to the functioning nerve, which recreates the feeling of touch. The researchers emphasize that this is a tested and safe technology that is suited to the human body and could be implanted anywhere inside of it once clinical trials will be done.

The technology was developed under the leadership of a team of experts from Tel Aviv University: Dr. Ben M. Maoz, Iftach Shlomy, Shay Divald, and Dr. Yael Leichtmann-Bardoogo from the Department of Biomedical Engineering, Fleischman Faculty of Engineering, in collaboration with Keshet Tadmor from the Sagol School of Neuroscience and Dr. Amir Arami from the Sackler School of Medicine and the Microsurgery Unit in the Department of Hand Surgery at Sheba Medical Center. The study was published in the prestigious journal ACS Nano.

The researchers say that this unique project began with a meeting between the two Tel Aviv University colleagues – biomedical engineer Dr. Maoz and surgeon Dr. Arami. “We were talking about the challenges we face in our work,” says Dr. Maoz, “and Dr. Arami shared with me the difficulty he experiences in treating people who have lost tactile sensation in one organ or another as a result of injury. It should be understood that this loss of sensation can result from a very wide range of injuries, from minor wounds – like someone chopping a salad and accidentally cutting himself with the knife – to very serious injuries. Even if the wound can be healed and the injured nerve can be sutured, in many cases the sense of touch remains damaged. We decided to tackle this challenge together, and find a solution that will restore tactile sensation to those who have lost it.”

In recent years, the field of neural prostheses has made promising developments to improve the lives of those who have lost sensation in their limbs by implanting sensors in place of the damaged nerves. But the existing technology has a number of significant drawbacks, such as complex manufacturing and use, as well as the need for an external power source, such as a battery. Now, the researchers at Tel Aviv University have used state-of-the-art technology called a triboelectric nanogenerator (TENG) to engineer and test on animal models a tiny sensor that restores tactile sensation via an electric current that comes directly from a healthy nerve and doesn’t require a complex implantation process or charging.

The researchers developed a sensor that can be implanted on a damaged nerve under the tip of the finger; the sensor connects to another nerve that functions properly and restores some of the tactile sensation to the finger. This unique development does not require an external power source such as electricity or batteries. The researchers explain that the sensor actually works on frictional force: whenever the device senses friction, it charges itself.

The device consists of two tiny plates less than half a centimeter by half a centimeter in size. When these plates come into contact with each other, they release an electric charge that is transmitted to the undamaged nerve. When the injured finger touches something, the touch releases tension corresponding to the pressure applied to the device – weak tension for a weak touch and strong tension for a strong touch – just like in a normal sense of touch.

The researchers explain that the device can be implanted anywhere in the body where tactile sensation needs to be restored, and that it actually bypasses the damaged sensory organs. Moreover, the device is made from biocompatible material that is safe for use in the human body, it does not require maintenance, the implantation is simple, and the device itself is not externally visible.

According to Dr. Maoz, after testing the new sensor in the lab (with more than half a million finger taps using the device), the researchers implanted it in the feet of the animal models. The animals walked normally, without having experienced any damage to their motor nerves, and the tests showed that the sensor allowed them to respond to sensory stimuli. “We tested our device on animal models, and the results were very encouraging,” concludes Dr. Maoz. “Next, we want to test the implant on larger models, and at a later stage implant our sensors in the fingers of people who have lost the ability to sense touch. Restoring this ability can significantly improve people’s functioning and quality of life, and more importantly, protect them from danger. People lacking tactile sensation cannot feel if their finger is being crushed, burned or frozen.”

Dr. Maoz’s laboratory:

https://www.maozlab.com/

  The article:

https://pubs.acs.org/doi/full/10.1021/acsnano.0c10141