03/11/2026 | Ana Luiza Figueiredo | Olhar Digital

https://olhardigital.com.br/2026/03/11/ciencia-e-espaco/por-que-estudo-da-polilaminina-ainda-nao-foi-publicado/ 

Article on polylaminin faces criticism from scientific journals due to data discrepancies and lack of prior registration of the clinical trial

The research on polylaminin, a substance studied for the treatment of spinal cord injuries, has not yet been accepted by scientific journals. The work was released in 2024 as a preprint, a preliminary version that has not yet undergone the formal peer review process.

The author of the study, Tatiana Sampaio, stated in an interview with g1 that the article will be revised to correct points criticized during the publication attempts. According to the researcher, the new version should correct errors identified in the manuscript and clarify aspects questioned by editors and specialists.

Why did some scientific journals reject publication?

When a scientific article is submitted to a specialized journal, it goes through a peer review process, in which other researchers evaluate the methodology, results, and conclusions of the study. Approval indicates that the work has undergone a technical analysis considered one of the main quality filters in science.

According to Tatiana Sampaio, the revised version of the article received rejections from three journals, including Nature Communications, another journal in the Nature group, and the Journal of Neurosurgery. Among the reasons cited by the editors are disagreements about the recovery rate used as a reference in the study and the absence of prior registration of the clinical trial in an international research database.

Disagreements in the recovery rate

In the study, the authors state that about 9% of patients with complete spinal cord injury recover some degree of motor function without treatment. This index is used as a baseline for comparison to evaluate the results observed after the use of polylaminin.

During the editorial review, reviewers questioned this number and indicated that the spontaneous recovery rate could be significantly higher, reaching close to 40% in some cited studies. The researcher contested this interpretation based on data used as a reference in her own work.

“The other two responses were somewhat similar. The conversion from A to C is much more than 9%,” explained Tatiana Sampaio. “The editor and the entire journal sent me an article published in the journal itself saying that the conversion was higher. Then I asked him: ‘look, you are wrong.’”

The difference is relevant because the spontaneous recovery rate influences the interpretation of the results. If the natural recovery is higher, it becomes more difficult to affirm that the observed improvement occurred because of the substance.

Lack of prior registration of the study

Another point raised by editors was the absence of prior registration of the clinical trial on ClinicalTrials.gov, an international database that gathers information on clinical research. Early registration is used to increase the transparency of scientific research. It documents, from the beginning of the study, the objectives, methods, and results that researchers intend to evaluate. This helps prevent changes to the research design after data begins to appear.

According to Tatiana Sampaio, registration was only done after the study began because she didn't know this was a requirement adopted by several scientific journals.

“The editor said he would send it for review, but the article remained in technical check because we hadn't registered with ClinicalTrials.gov. They only publish when there is prior registration. And we did it afterward. If you ask me why it was afterward, I'll tell you honestly: because I didn't know,” said the researcher.

After the rejections, the researcher stated that she intends to revise the text and submit it to journals that usually publish single-arm clinical studies, without a control group or placebo. To deal with the criticism received, she also reported consulting artificial intelligence tools.

“What I did was this: I asked ChatGPT for help. I said, ‘I’m seeing people arguing that it’s not worth it, that it doesn’t work, that I don’t know what.’ Then it gave me several pieces of advice,” she told g1.

What errors will be corrected in the article?

Tatiana Sampaio stated that she intends to correct errors identified in the preprint and add explanations about points raised during the editorial process.

One of the adjustments involves an error in a graph. In the current version, participant 1 appears with approximately 400 days of follow-up, although the text indicates that he died five days after the procedure. According to the researcher, the data actually belongs to participant 2 and there was a typo in the figure.

Another point involves how the electromyography exam used to indicate possible regeneration in one of the patients was presented. Experts pointed out that, in some cases considered successful, the exam did not show clear changes. The researcher said that the image displayed in the article was "poorly programmed" and showed raw data.

Explanation about spinal shock

Experts also raised the possibility that some patients might have been in spinal shock at the time of the initial evaluation. This is a temporary phase that can occur after a spinal cord injury, with loss of reflexes and nerve activity below the site of the trauma.

This state can interfere with tests used to classify the severity of the injury, making it seem more severe than it actually is. In the original preprint, this condition was not detailed.

According to Tatiana Sampaio, the revised version of the text should clarify that none of the patients were in spinal shock and that all underwent tests to assess this possibility. She states that the gold-standard procedure, which requires several days of observation, was not used because polylaminin needs to be applied within 72 hours of the injury.

Is polylaminin effective and safe?

The results described so far are considered preliminary. The research had good results in animals and subsequently in a small group of eight patients, which is what appears in the preprint.

The study's impact led to a partnership with the Brazilian laboratory Cristália and authorization from the National Health Surveillance Agency (ANVISA) to begin a clinical study aimed at evaluating the safety and efficacy of the substance.

Despite this, researchers, doctors, and scientific entities have reinforced the need for caution when interpreting the results. Tatiana Sampaio herself states that it is not yet possible to say that the substance works.

Among the eight patients, the evolution was different in each case. The episode of Bruno Drummond de Freitas, who regained the ability to walk, is isolated. Another patient showed improvement but then regressed after interrupting physiotherapy. “He used to be able to move against gravity. Today I know he can't anymore, because he stopped doing physiotherapy,” she explained.

In the preprint, the researchers also state that it is not possible to rule out risks. Deaths from pneumonia and sepsis recorded among participants could, in principle, be related to a possible immunosuppressive effect of polylaminin.

“You evaluate their progress and see that it is progress compatible with the general progress of spinal cord injury, but there are only eight patients, so it is not possible to completely rule out the possibility that there may be some negative effect of polylaminin,” assesses the researcher.

What are the next steps in the research?

The initial study was conducted in a single-arm format, in which all participants receive the treatment. This model makes it difficult to compare with patients who did not receive the substance.

Therefore, the researcher stated that she is evaluating the possibility of using a matched control group. In this method, patients from large international studies on spinal cord injury who have characteristics similar to those of the Brazilian volunteers treated with polylaminin would be selected.

According to her, the data from these patients would be used for comparison with the study results.

“You take the data from this person, both from the initial hospitalization and the follow-up, and monitor what happens to them. And if you have a large enough number of patients, you end up with a universal control group,” said Sampaio.

In parallel, the research should advance to the formal stages of clinical trials. Phase 1, focused on evaluating safety, was approved in January by Anvisa (Brazilian Health Regulatory Agency) and is awaiting analysis by an ethics committee.

If safety is confirmed, the tests can advance to phases 2 and 3, when efficacy, appropriate doses, and possible adverse effects in larger populations are evaluated. If these stages are successful, the researchers can request sanitary registration so that the drug can be marketed.