CNN
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For centuries, Thailand luxury silk fabric, exported all over the world.
But biomedical researchers at Bangkok’s Chulalongkorn University have discovered another use for this fiber: delivering drugs into the body.
Drug delivery systems come in a variety of formats, from swallowed capsules and tablets to skin patches, ointments, and various types of injections.
It can be used to encapsulate silk fibroin, one of the natural proteins that gives silk its incredible strength, said Jutamas Ratanavaraporn, director of Chulalongkorn University’s Biomedical Engineering Research Center. It is a sac-like drug that takes longer to break down than other natural proteins such as gelatin or chitosan, releasing the drug into the body more slowly.
“Instead of requiring large or frequent dosing, protein capsules can gradually release just the right amount of drug the body needs. This controlled release reduces overall dosage and side effects. It helps reduce risk,” says Ratanavaraporn.
Ratanavaraporn, who has been researching silk for more than 17 years, spun out his research and founded the company in 2021 with two other professors from his research team. Their startup, EngineLife, is commercializing their research, with its first product, an insomnia treatment delivered via a skin patch, approved by Thailand’s FDA and brought to market earlier this year. Ta.
Silk fibroin has been attracting the attention of scientists for more than a year. centuryhas been widely studied for biomedical applications.
Biocompatible (does not harm body tissues), sustainable and cost-effective, silk fibroin has many advantages over materials currently used as natural and synthetic drug carriers. says. Yajun Shuaia researcher at China’s Zhejiang University Institute of Applied Bioresources, was not involved in Ratanavaraporn’s research.
Shuai said silk fibroin is produced using “simple and safe methods” and is less likely to cause negative side effects compared to other natural proteins or synthetic drug delivery systems.
Many of the advantages of silk fibroin over other natural polymers come down to its characteristics. structure: It has a strong and stable ‘beta sheet’, which allows it to act in ways that other proteins cannot, such as slow release of drugs, giving it strength and flexibility, says Zhejiang Biological Resources. says Minying Yang, who is also a researcher. University.
“Many drug traffickers are like sprinters, fast but short-lived. Silk fibroin is like a marathon runner, supporting long-term drug release,” Shuai added. .
Describing silk fibroin as a “chameleon of materials,” Yang said its strength and flexibility give it a wide range of applications in the medical field, while offering greater safety and sustainability than other materials. I am.
“Silk fibroin’s degradation rate is like a switch and can be adjusted from days to months to suit the drug’s needs. This level of control is difficult to find with other drug carriers.” Shuai says Mr.
Silk fibroin has been studied for the following purposes: all From bone tissue scaffolds to films for corneal transplants. However, very few products have been launched on the market. Scientific Review 2022 The study found that only 3% of the 697 studies reached clinical trials, and even fewer were commercialized. The U.S. Food and Drug Administration has approved the following uses: silk fibroin suture That was more than 20 years ago, and only a few silk-based medical uses have been approved since then. silk bridgenerve conduit, and silk voicean injectable implant to help the vocal cords.
One of the key challenges is the variability of silk.
In Thailand, most silk is produced From silkworms on a small family farm in the countryside. It is kept all year round. However, changes in season, climate, and feed can cause slight changes in the cocoon.
This is less of a problem when producing silk fabrics. But when it comes to medicine, consistency is key, said Chuanbing Mao, a biomedical engineering professor at the Chinese University of Hong Kong who was not involved in Ratanavaraporn’s research.
“For practical medical applications, we need to obtain a highly purified product,” Mao says, highlighting a problem that has not yet been solved at scale, adding that the same “reproducible He added that creating “products” is a major challenge.
According to Ratanavaraporn, even small differences in feed or climate can change the molecular weight of silk proteins, a problem that Engine Life is trying to address, which could also affect the rate of degradation and the timing of drug delivery. It is said to change.
To standardize the quality of silk fibroin, Engine Life began experimenting with different agricultural processes and techniques, right down to the soil used to grow the mulberry leaves that the silkworms eat. The company currently has strict standards in place, including a dedicated breeding facility for silkworms that controls temperature and humidity to create a stable environment year-round.
“We need to ensure that the silk production process is as stable as possible and consistent from batch to batch,” says Ratanavaraporn.
Regulatory approval is another barrier to bringing such novel innovations to market. EngineLife requires products to be registered in various categories. Thai FDARatanavaraporn added that depending on the drug and the method of administration, “this is the most difficult step for us and consumes a huge amount of budget and time.”
slow and steady
Currently, EngineLife’s farms produce approximately 25-30 kilograms of silk cocoons per year, which can produce one million doses of medical-grade silk fibroin solution. However, Ratanavaraporn points out that the pilot plant to extract fibroin has a maximum production capacity of 30,000 doses of medical-grade silk fibroin solution, and there is still work to be done to scale it up.
Meanwhile, the company continues to develop new treatments.
Ratanavaraporn says her research is currently focused on two applications. One is a transdermal patch, which delivers the drug externally through a small patch on the skin. Injectable hydrogel made using silk fibroin.
The company started selling CBD silk fibroin patches for insomnia in Thailand earlier this year, and Ratanavaraporn believes this is the first product on the market to use silk fibroin vesicles for drug delivery.
The team is currently working on its next product, an injectable hydrogel for osteoarthritis, a type of joint disease. Currently, patients typically receive an injection in the knee that provides pain relief for varying periods of time. one week to several months. During the course of his research, Ratanavaraporn discovered that silk fibroin can stay in the body for up to six months, allowing the drug to be released slowly and reducing the number of injections.
“For many diseases and conditions, we don’t need a single injection to cure everything. Instead, we need a sustained release of the drug over a long period of time,” she says.
Ratanavaraporn hopes that silk fibroin will be used in more drug delivery systems to help patients across Thailand and abroad, thereby providing a new source of income for Thai silk farmers. I hope that it will be possible.
“Silk already has a high value as a fabric.” she says, “But now we’re positioning it as a medical-grade material, increasing its value at least tenfold.”
