New Biomaterial Delivers Medication Directly to Fish Intestines

Photo of author

By Milthon Lujan

Researcher administering biomaterial to Amazonian ornamental fish. The bioparticle was well received by the animals, paving the way for its use in species intended for human consumption. (Photo: Omar Mertins)
Researcher administering biomaterial to Amazonian ornamental fish. The bioparticle was well received by the animals, paving the way for its use in species intended for human consumption. (Photo: Omar Mertins)

The increasing bacterial resistance to conventional antibiotics has become a threat to public health, necessitating the development of new, practical biomaterials to combat bacterial resistance.

A new biomaterial developed by the Universidade Federal de São Paulo (Unifesp) may help reduce waste and pollution resulting from the excess of pharmaceuticals in water.

This bioparticle can deliver medications directly to fish intestines, helping combat microbial resistance to conventional antibiotics.

Furthermore, the biomaterial has proven to be palatable to animals, enhancing the effectiveness of treatments and reducing waste and contamination associated with fish medication administration.

It’s important to note that the nanodelivery of drugs aims to ensure drug stability under adverse biochemical conditions during administration.

New Biomaterial for Antibiotic Transport

A recent study produced submicrometric antibacterial activity bioparticles in the form of a powder with suitable texture and appealing features for effective oral administration.

“Our bioparticle can pass through the digestive tract and deliver the drug directly to the intestine, potentially enhancing the effectiveness of conventional medications, to which bacteria are increasingly resistant,” said Patrick Mathews Delgado, a postdoctoral researcher at the Escola Paulista de Medicina (EPM) of Unifesp and co-author of the study.

“The material can be administered directly in the water, where it is consumed by the fish. Typically, medications are mixed with feed, making it impossible to determine how much was actually consumed and how much is contaminating the water. This becomes a serious problem in large fish farms, such as salmon in Chile, for example,” the researcher emphasized.

See also  Reveal the environmental impact of Nile tilapia farming by harvest weight

The bioparticle is based on chitosan and alginate, two natural ingredients used in both industry and research. Chitosan is obtained from crustacean shells, and alginate is derived from macroalgae.

Arginine, an amino acid found in various foods, was added to the formulation. The antimicrobial molecule used was a peptide obtained from a spider found in southeastern Brazil.


Amazonian ornamental fish of the species Corydoras schwartzi were treated with the material for eight days.

The analysis of fish intestines revealed high penetration into epithelial cells and deeper organ chambers. Various tests demonstrated that the particle did not cause toxicity or other harm. Additionally, examinations of the fish’s blood cells reinforced these findings.

“We used materials known to be low or non-cytotoxic. Chitosan has the advantage of adhering well to the mucosa, as demonstrated in the study. Tests showed that the biomaterial withstands the acidity of the digestive system and delivers the drug intact to the intestine,” explained Omar Mertins, a professor at the Department of Biophysics at EPM-Unifesp, who led the study.

The study concludes by highlighting the potential applicability of a new biomaterial for attractive and safe oral administration of antibacterial polypeptide.

The study is part of the projects coordinated by Mertins: ““Aperfeiçoamento das propriedades do polissacarídeo quitosana para aplicação em lipossomas e vesículas gigantes” (Improvement of the properties of the polysaccharide chitosan for use in liposomes and giant vesicles)” and “Nano cubossoma de fase cristalina e funcionalizado com biopolímeros: desenvolvimento como carreador de fármaco e estudos in vivo em zebrafish (Danio rerio)” (Nano cubic crystal phase and biopolymer-functionalized for drug carrier development and in vivo studies in zebrafish).

See also  Genetic engineering to enhance the profitability of microalgae production

Parasites in Ornamental Fish

In a previous study, the researchers evaluated the properties of a similar formulation, targeting parasites affecting Corydoras.

The transported molecule was the antiparasitic “Praziquantel,” widely used in treating parasitic infections.

“Ornamental fish are mainly exported to Asia, Europe, and the United States, and they can carry a large number of parasites. The introduction of new pathogens through these exports poses a significant risk to ecosystems and commercial production because they can contaminate wild and cultivated species,” explained Mathews.

In the intestines of animals colonized by worms, the bioparticle penetrated cysts to protect the parasites, demonstrating the material’s potential for use as a drug carrier for other fish. A patent application has been filed for one of the formulations based on the results of the previous study.

According to the previous study, the drug target was released, and more than 97% of intestinal parasites in the fish were reduced.

Currently, scientists are testing this and other formulations for treating parasites in commercially consumed fish, such as tilapia (Oreochromis niloticus) and cachama (Colossoma macropomum).

Carlos A.B. Ramirez, Patrick D. Mathews, Rafael R.M. Madrid, Irene T.S. Garcia, Vera L.S. Rigoni, Omar Mertins. 2023. Antibacterial polypeptide-bioparticle for oral administration: Powder formulation, palatability and in vivo toxicity approach, Biomaterials Advances, Volume 153, 2023, 213525, ISSN 2772-9508,

Mathews, P. D., Patta, A. C., Madrid, R. R., Ramirez, C. A., Pimenta, B. V., & Mertins, O. (2021). Efficient Treatment of Fish Intestinal Parasites Applying a Membrane-Penetrating Oral Drug Delivery Nanoparticle. ACS Biomaterials Science & Engineering.

Source: Information provided by Agencia FAPESP.

See also  At the doorstep of a RAS breakthrough

Leave a Comment