by P. J. S. Bártolo and A. Mendes
Institute for Polymers and Composites, Department
of Mechanical Engineering,
School of Technology and Management, Polytechnic
Institute of Leiria, Portugal.
pbartolo@estg.ipleiria.pt
Abstract: Hydrogels have
received much attention due to their potential
use in a wide variety of biomedical applications,
including tissue engineering scaffolds, drug delivery,
contact lenses, corneal implants and wound dressing.
Most hydrogels are usually synthesized using reactive
monomers and cross-linkers. However, they do consume
non-renewable resources, employ hazardous manufacturing
steps and are not biodegradable, on top of not
being always biocompatible so their use in medical
applications is limited. Consequently, research
attention has been centred on generating hydrogels
from natural and biocompatible polymeric materials,
such as collagen, gelatin, chitosan and alginate.
Biomaterials, due to their particular properties,
such as biocompatibility, biodegradability, sensitivity
to some external pH, electrical or temperature
stimuli, can be extensively used in biotechnology
and medical applications.
This research study focuses on a
new route to produce three-dimensional patterns
in alginate hydrogels for medical applications,
through the use of a biomimetic layer-by-layer
free form manufacturing system. In this new biologic
manufacturing system alginate structures are produced
by extruding a solution of sodium alginate in
water (previously prepared) mixed with a solution
of calcium chloride, both of known concentration.
The building process to obtain three-dimensional
gel structures is described, from a chemical point
of view and some produced structures are presented.
It is also examined the effect of the alginate
concentration over both the kinetics and accuracy
(shrinkage) of the gelation process and morphological
structure.
