Biomedical Engineering Reference
In-Depth Information
behaviour could be interpreted by considering the low degree of substitution typically
obtained with this type of macromer (Figure 5) and subsequent low degree of crosslinking.
The final hydrogels resulted more hydrophilic, as demonstrated by the highest swelling
degree values (SD%) obtained, and less crosslinked thus leading to network with weak
mechanical properties.
Fig. 11. Pictures of the swollen hydrogels obtained after 2 days of immersion in the swelling
medium (phosphate buffer, 0.1M, pH 7.4).
The swelling degree values obtained with UMA- and UA-based macromers resulted to be
similar thus indicating a similar density of crosslinking inside their structure. The
interpretation of these datas are not straightforward since UMA-based hydrogels were
expected to be less hydrophilic and more crosslinked due to the higher amount of
polymerizable group contained in their structure. Indeed the final texture of the UMA-based
hydrogels indicated a better mechanical stability in respect to the other type of hydrogels.
The unexpected lower SD (%) values obtained with UA-based hydrogels could be explained
by the loss of material during the swelling experiments.
4. Conclusion
Ulvan, a sulphated polysaccharide of algal origin, is worth of deeper attention for its
potential use in technological and industrial-related applications. The exploitation of this
abundant and renewable resource could represent an advantageous alternative approach to
the use of fully synthetic materials based on fossil fuel feedstock.
In particular Ulvan represents an intriguing candidate material for biomedical applications
due to its intrinsic beneficial biological activities and the possibility of easily modifying its
structure according to the envisaged application. Its chemical structure similar to that of
natural glycosaminoglycans such as chondroitin sulphate and hyaluronic acid make Ulvan
an attractive candidate for their substitution or use in related applications.
