Bacteria-responsive materials for drug delivery

​Resistant bacteria is a growing problem in the whole world. The reason is that antibiotics often is used more often than necessary. In infected wounds, especially chronic wounds which are common for patients with diseases such as diabetes where the blood circulation is poor, antibiotics is used.

Marina Craig, who recently finished her industrial PhD studies within SuMo Biomaterials in a cooperation between Chemistry and chemical engineering at Chalmers and Mölnlycke Health Care, saw a possibility to develop a material that could lead to reduced use of antibiotics by letting the infection itself distribute the antibiotics.

The material Marina Craig has been studying is a nano film that works as a barrier between bio active substances, for example drugs, and the bacteria’s degradation enzymes, protease. The inside of the barrier holds drugs suited to kill bacteria. When the bacteria’s protease degrades the barrier the bacteria is exposed to drug and it dies.

Tell us about the material
It is a nano film made of polypeptides. The thin film can be used as a surface around a very small capsule with drugs for one or more bacteria. The film is degraded by the bacteria’s protease. The protease IMicrocapsules loaded with antimicrobial drugs assembled using template assisted assembly and layer-by layer technique. have focused on are specific and unique for each kind of bacterial strain in that matter that they only degrade specific kinds of surfaces. I put a lot of effort in finding the right kind of protease and the right kind of polypeptide that are suited for fighting two kinds of bacteria that are causing disease, Staphylococcus aureus and Pseudomonas aeruginosa. Since the degradation of the barrier depends on the amount of protease surrounding it, the amount of exposed drug will also be in proportion to the bacteria causing disease.

Polypeptides already exist and is no discovery in itself. What I have done is finding a new way of using them and show a connection that no one has seen before when it comes to designing barriers to suit the protease.

Why does it mainly suit treatment of chronic wounds?
That’s where the biggest problems lie. Those who have an underlying problem like for example diabetes also have a higher risk of having problems with chronic wounds because of poor blood circulation. The idea is that as much as possible is treated locally, instead of exposing the whole body to drugs when you have an infection.

What would a finished product look like?
That is not part of the study, but it could be used in bandages, gel or crème. I haven’t looked into the product, but instead focused on getting the system to work.

What’s the next step?
We’re not working with it at the moment because of problems with the patenting, but who knows, perhaps it becomes real in the future. At least now the knowledge is out there.

What benefit do you find in working within SuMo BIOMATERIALS?
It has been really great since I work alone and don’t belong to a group. The SuMo members were always there to help. Everyone wanted to help and I tried to help others when I could. It is a well-functioning centre in which we exchange knowledge and favours.

Text: Mats Tiborn
SuMo Biomaterials is a Vinnova (Swedish government agency) supported research consortium between academia (Chalmers University of Technology and SP Food and Bioscience) and industry (AkzoNobel, AstraZeneca, Mölnlycke Health Care, SCA, Stora Enso and Tetra Pak). The focus of the centre is on understanding and developing properties of soft biomaterials.
The concept of SuMo Biomaterials is to use industrial needs to create innovations and academic excellence in science with the long term goal to generate added value for industry, academia and society.


Page manager Published: Wed 20 Jan 2016.