Published on: 2026-08-13
Source: Peter the Great St. Petersburg Polytechnic University –
An important disclaimer is at the bottom of this article.
Scientists at Peter the Great St. Petersburg Polytechnic University have developed a carrier that delivers natural anti-tumor substances from broccoli seeds to colon tumors. The external gelatin shell allows the capsule to pass through the acidic environment of the stomach without loss, while the calcium carbonate particles inside release the active substance directly in the intestine and the tumor itself. Experiments on mice showed that combined with a standard chemotherapy drug, the system enhances the therapeutic effect and allows for lower doses. The research results were published in the international scientific journal ACS Applied Materials & Interfaces.
Colorectal cancer remains one of the most common oncological diseases worldwide. A promising strategy in combating it is considered to be the use of targeted delivery of antitumor substances directly into the malignant formation. This way, the medication begins to act precisely in the affected area and does not exert toxic systemic effects on the entire body. One possible approach to cancer therapy includes the use of isothiocyanates—natural compounds abundant in broccoli, watercress, and white cabbage. The high biological activity, including antitumor properties of isothiocyanates, is extensively researched worldwide. However, there are several limitations preventing the active introduction of products based on them into the real economic sector. Primarily, these are related to their poor stability in the aggressive acidic environment of the stomach, which leads to poor absorption, non-selective distribution throughout the body, and premature degradation. As a result, the therapeutic effect turns out to be weak and unstable.
The restrictions were overcome by employees of the Laboratory of Nano- and Microencapsulation of Biologically Active Substances at the Institute of Biomedical Systems and Biotechnology of SPbPU. The researchers assembled a carrier based on the principle of a matryoshka doll—capsules inside a capsule. The active substance, extracted from broccoli seeds, was placed by the scientists into calcium carbonate microparticles, which were then packed into gelatin spheres. The outer gelatin layer acts as armor: it breaks down much more slowly under the action of gastric juice and preserves the active molecules intact as they pass through the stomach. In the intestine, the gelatin is broken down by the enzyme trypsin and releases the calcium carbonate microparticles with the packed isothiocyanates.
We took an available, inexpensive, and renewable raw material — broccoli seeds, developed an effective and simple method for extracting a mixture of isothiocyanates, and learned how to deliver them to the required area. The idea lies in double protection: the gelatin shell carries the drug through the stomach, and the calcium carbonate inside opens only in the acidic environment of the tumor and gradually releases the active substance. Such a carrier is taken orally, not injected. This significantly simplifies treatment for the patient. Moreover, it works in conjunction with classical chemotherapy, enhancing it,
Scientists obtained isothiocyanates from ground broccoli seeds. After homogenization and brief enzymatic treatment, the raw material yields a mixture of active isothiocyanates. Calcium carbonate microparticles are synthesized by simple precipitation from salt solutions at room temperature, without aggressive reagents. The key property of such a mineral carrier is its sensitivity to acidity: it is stable in a neutral environment but dissolves and releases active compounds in the acidic environment characteristic of tumor tissue and intracellular lysosomal vesicles (pH around 4.5–5.5). The system’s performance was tested on three model media simulating the stomach, intestines, and intracellular environments, and then on a culture of colon cancer cells, three-dimensional cell spheroids, and mice with grafted intestinal tumors.
The scientists’ main focus was on the combination of a natural substance with the standard chemotherapy drug 5-fluorouracil. According to the researchers, the tumor was most strongly suppressed in the group of animals that received the composite carrier along with 5-fluorouracil. Formal analysis confirmed the effective combined action of the two substances, which turned out to be greater than the sum of their effects individually: the combination index dropped to 0.73–0.76 (a value below one indicates synergy). In practice, this means that the desired result can be achieved with lower doses, thereby reducing the toxic load on the body. At the same time, the carrier itself proved safe: compatibility tests with blood cells revealed no destruction of erythrocytes.
Similar systems based on calcium carbonate are being developed in many laboratories, but we combined several ideas at once: natural components, a two-level delivery system, and a combined effect with an active chemotherapeutic drug. It is this combination that produced a synergistic effect. Our current task is to optimize the process of extracting isothiocyanates from natural raw materials, further modify the carriers, and also test the platform on other types of tumors, — explained senior researcher of the Laboratory of Nano- and Microencapsulation of Biologically Active Substances at SPbPU, Timofey Karpov.
The most obvious application of this development is colorectal cancer, where it is important to simultaneously create a high concentration of the drug in the tumor itself without harming healthy tissues. Oral administration makes such therapy less traumatic and more convenient, while reliance on inexpensive plant raw materials and simple synthesis leaves room for scaling up.
The work was carried out with the support of the Russian Science Foundation (No. 25-15-20047) and the St. Petersburg Science Foundation.
Please note; This information is raw content obtained directly from the source. It is an accurate report of what the source claims and does not necessarily reflect the position of MIL-OSI or its clients.