Modification of biopolymers

Through chemical modification, we specifically adapt biopolymers, such as gelatin, chitosan or inulin, to different requirements. By adding various chemical functions, such as methacrylic groups, thio groups and benzophenones, we can change, for example,  the viscosity, solubility or charge of the biopolymer in a targeted manner, making processes more sustainable and efficient.

Modification reaction in the 1 liter reactor.
© Fraunhofer IGB
Modification reaction in the 1 liter reactor.

Modification process

In order to achieve optimal conversion and variable degrees of modification of the biopolymers, various parameters can be adjusted as desired during modification, such as the temperature, the pH value through the use of a buffer or a titrator, or even the dosage of the reagents. Furthermore, we use the possibility of modification under inert gas or vacuum (for oxygen-sensitive reagents) or also under UV exclusion (for light-sensitive reagents).

Purification of modified biopolymers via a tangential flow system.
© Fraunhofer IGB
Purification of modified biopolymers via a tangential flow system.

Various purification options, such as dialysis or tangential flow filtration, also guarantee rapid elimination of unwanted impurities in the product. Low-temperature drying processes such as freeze-drying or spray-drying ensure gentle drying of the modified biopolymers and enable the product to be obtained in various forms, e.g. as a powder.

In addition, the modifications can be carried out in different scales, from a few milligrams to 100 grams, depending on the biopolymer.

Freeze-drying of modified biopolymers.
© Fraunhofer IGB
Freeze-drying of modified biopolymers.


By attaching crosslinkable or hydrophobic groups, more stable and insoluble systems can be created, among other things. For example, modified inulin can be used in drug delivery systems for the encapsulation of active ingredients, or modified chitosan can be used in the production of functional water-repellent layers on textiles. The modification of biopolymers is also of interest for printing and 3D printing processes, as it allows, among other things, the viscosity to be adjusted independently of temperature.


February 2021 – January 2024


Expanding the possible applications of renewable raw materials in textile finishing based on the biopolymer chitosan

A project coordinated by Fraunhofer IGB has successfully demonstrated how textiles can be finished using chitosan in combination with bio-based hydrophobic molecules – as an environmentally friendly alternative to perfluorinated chemicals. This innovation could replace PFAS finishes with fewer requirements. The developed formulas have already been successfully adapted to various materials, including paper and cardboard.


August 2017 – January 2021


Bio-based hydrophobic and dirt-repellent finish for the substitution of pPerfluorochemicals (PFCs) on textile surfaces with chitosan derivatives

The aim of the Hydrofichi project is to modify textile surfaces using renewable raw materials in order to replace environmentally harmful and toxic agents that have been used up to now. For this purpose, a chitosan-based hydrophobic finishing of textiles is being developed.


January 2017 – December 2019


Personalized orthopedic implants through biomechanical stimulation of hybrid materials

There is an increasing interest in personalized therapies for the treatment of injuries or age‑related degeneration of cartilage tissue. One solution is the production of individual cartilage implants using additive manufacturing methods. For this purpose, Fraunhofer IGB is developing gelatin‑based hybrid hydrogels that mimic the natural tissue environment of cartilage cells and thus promote the biofunctionality and matrix production of the cells.


November 2011 – October 2015

ArtiVasc 3D

Artificial vascularized carrier systems for 3D tissue regeneration.

The supply of nutrients to multilayered cell layers is a hitherto unsolved challenge in regenerative medicine.


High Performance Center Mass Personalization


(Diagnostics, medical engineering)