Design and application of functional gelatin-based biomaterials as drug and cell carriers

Abstract text (incl. figure legends and references)

Introduction

Gelatin is an attractive starting material in the design of biomaterials due to its inherent degradability, cell adhesion sequences, and hydrogel forming properties that provide environments to cells close to their natural environment, the extracellular matrix. However, gelatin needs to be crosslinked to allow tailoring of properties.

Objectives

Tailoring and using functional gelatin-based materials.

Materials and Methods

Aq. solutions of gelatin functionalized with alkynes1 or alkenes2 are crosslinked through alkyne-azide cycloaddition or by photopolymerization. In the former case, crosslinking was performed with variation of small diazide crosslinker type and amount. Hydrogel mechanical properties were tested by rheology, and gelatin chain organization by WAXS, Glycidylmethacrylated gelatins were photocrosslinked in an aqueous two-phase systems in the presence of cells. Cell viability and proliferation, and release of functional proteins were investigated.

Results

Specific crosslinking with small bifunctional crosslinkers allowed tailoring of mechanical properties and rate of degradation of gelatin-based hydrogels, while unreacted groups were used for attaching dexamethasone via a second click chemistry reaction. Cell encapsulation was achieved without affecting cell viability. Encapsulated L929 and RAMOS Blue cells proliferated and released functional proteins (MMP-9 or secreted embryonic alkaline phosphatase).

Conclusion

Gelatin crosslinking can be performed in aq. solutions using a variety of organic polymer-analogous reactions. The crosslinking allowed tailoring of material properties and degradation, and enabled access to functional biomaterials e.g. suitable as drug or cell carriers.

1: Eur. Polym. J. 2018, 100, 77-85.

2: Eur. Polym. J. 2021, 142, 110148.