Controlled Release of Growth Factors in Bioprinted Respiratory Scaffolds:

Tissue engineering is a rapidly evolving field that seeks to stimulate and control tissue generation and regeneration by incorporating cells, biocompatible materials, and bioactive molecules. Both the mechanical and chemical environments provide cues and signaling factors that significantly influence cellular development. Among these, growth factors are key signaling molecules in the biochemical environment that play a crucial role in initiating and regulating cellular activities.

A promising approach in tissue engineering is the use of nanoparticle systems for the controlled release of growth factors. This technique aims to mimic the biochemical environment of native tissues. A recent study done by researchers at the University of Saskatchewan, Canada, has made significant strides in this area, developing a chitosan-coated alginate-based nanoparticle system loaded with hepatocyte growth factor. This system was then incorporated into bioinks, which were then used to bioprint three-dimensional scaffolds containing human pulmonary fibroblasts and bronchial epithelial cells.

Our BioScaffolder 3.2 was used to print the scaffolds by pneumatic extrusion. The printability of the base bioink was assessed using this device, along with the optimal printing speed and pressure. The BioScaffolder 3.2 was also used to print different scaffolds to test the tensile strength, to determine whether there was a difference between the mechanical stability of the scaffolds containing nanoparticles and that of those not containing nanoparticles. Additionally, the study aimed to determine whether the inclusion of 20 mmol CaCl2 in the culture media allowed the maintenance of the scaffold mechanical properties over the 14-day culture period.

The bioink loaded with a concentration of 4 µg/mL of nanoparticles had better printability and the mechanical stability of the scaffolds was maintained over a 14-day culture period. The cells incorporated in the scaffolds showed high viability and proliferation.

The chitosan coating on the nanoparticles was found to decrease the release rate and lessen the initial burst release of the growth factors. This controlled release is critical in maintaining an appropriate therapeutic window, particularly in bioprinted scaffolds.

This study demonstrates the successful synthesis and application of a controlled release system of growth factors in tissue-engineered respiratory tissue scaffolds, and in GeSiM we’re proud to contribute with our technology to the development of new therapeutic approaches in the tissue engineering field.


This article is based on the following publication:

Zimmerling, A.; Sunil, C.; Zhou, Y.; Chen, X. Development of a Nanoparticle System for Controlled Release in Bioprinted Respiratory Scaffolds. J. Funct. Biomater. 2024, 15, 20. https://doi.org/10.3390/jfb15010020