Various encapsulation materials have been reported to improve the
chemical stabilities of natural bioactive components for extending their
shelf life and preserving functionalities [18]. Due to its nontoxicity, high
biocompatibility and tunable biodegradability, alginate, a natural biopolymer
extracted from brown algae, has been one of the most popular
agents in storage-stabilization, controlled release as well as stem cell
encapsulation and their further cryopreservation [19,20]. The prominent
feature of using alginate is its ability to form three dimensional matrices
by means of ionic crosslinking, thus to minimize the interaction
between encapsulated components and other factors (e.g. oxygen,
light or moisture) [21]. In addition, alginate has the ability to release encapsulated
bioactive components in the aqueous environment in a pHdependent
manner. The release rate is inhibited in acidic environment
(pH ~2), however, a time-dependent release can occur at physiological
pH(~6 to 8) which leads to enhanced bioavailability [22]. Hence, encapsulation
of broken sporoderm GLS using alginate not only protects the
bioactive ingredients from deteriorative processes, but also provides a
robust means to deliver concentrated ingredients to targeted site and
thus boost their beneficial effects, e.g. inhibition of the growth of
tumor cells [23].