Developing polymeric membranes capable
of modulating
the release
of compounds by controlling their surface properties and structure
represents an important challenge for efficient drug and active agent
delivery systems. Herein, we combine the two properties of polymeric
fibers, on the one hand, the core–shell structure and, on the
other hand, the control of wettability, to manufacture polymeric membranes
with dual and delayed release capacity of active agents. Fibers consisted
of a shell of derivates of poly(styrene-co-maleic
anhydride) functionalized with amino acids of different hydropathic
indexes and loaded with silver nanoparticles and a core of poly(vinyl
alcohol) containing allantoin, both used as antibacterial and healing
active agent, respectively. Silver ion release profiles were characterized
by two regimes that were reminiscent of the core–shell structure
of the fibers. An initial lag phase governed by diffusion was followed
by a higher release rate driven by a diffusion front of allantoin
from the center of the fiber until it reached the external environment.
The allantoin release profiles were well-fit by a first-order model,
where the saturation value was related to the wettability of the membranes.
Our results show how the control of wettability and the core–shell
configuration of the fibers may be a strategy for creating a versatile
polymeric platform for a fine-tuned release of active agents for biomedical
applications.