Background

Collagen is one of the most abundant proteins in the body and therefore a suitable biomaterial for Drug Delivery. Due to its weak stiffness and huge swelling degree the treatment with Rose Bengal and green light might improve the mechanical properties [1,2]. Such a photochemical crosslinking could affect the activity of adsorbed biomolecules as well as drugs. To investigate the influence of RBX treatment, BMP-2, SDF 1α and Vancomycin were coated on two collagen scaffolds (Atelocollagen and Collagen Solutions) with subsequent light treatment and activity testing

Methods

Collagen scaffolds were coated with BMP-2, SDF 1α and Vancomycin by adsorption. The activity of BMP-2 was tested on human osteoblasts through the alkaline phosphatase activity (ALP) and the proliferation capacity was tested under influence of SDF 1α in HUVECs. For Vancomycin the coated collagen was investigated regarding its bacterial growth-limiting effect on Staphylococcus aureus.

Results

Treatment of RBX resulted in no differences in the inhibition of bacterial growth when collagen scaffolds coated with Vancomycin. Whereas human osteoblasts showed a significant higher ALP activity on Collagen Solutions with BMP-2, no differences were measured on Atelocollagen. Additionally no significant differences in the used concentrations (100 and 500 ng) were measured after RBX treatment. HUVECs showed a higher proliferation when incubated on SDF 1α containing scaffolds.

Conclusion

The use of RBX for crosslinking is a useful tool to improve the mechanical properties of collagen for Drug Delivery. In this context the bioactivity of biomolecules could be influenced by this treatment. In the present study it could be shown that the effect of RBX not only depends on each molecule or drug but also on the scaffold which is used. For this reason it is important to evaluate the influence of the photochemical crosslinking method for the respective application.

References

[1] Chan, B.; So, K.F. Photochemical crosslinking improves the physicochemical properties of collagen scaffolds. J. Biomed. Mater. Res. Part A 2005, 75, 689–701

[2]Chan, B.; Chan, O.; So, K.-F. Effects of photochemical crosslinking on the microstructure of collagen and a feasibility study on controlled protein release. Acta Biomater. 2008, 4, 1627–1636