INJECTABLE HYDROGELS AS BIOMATERIALS - Advanced Biomaterials: Fundamentals, Processing, and Applications - page 194

6.5b shows human foreskin fi broblast cells encapsulated in the gel after three
days in culture stained using Live Dead staining. The ability of the chitosan-AHP
system to undergo fast gelation at physiological temperature without chemically
modifying the polymer and at very low concentrations of AHP makes this system
highly suitable as a protein and cell delivery vehicle.
6.4 CONCLUSIONS
The last decade saw a tremendous growth in developing unique biocompatible
injectable hydrogels for biomedical applications due to the several advantages
of in situ forming gels compared to implantable systems. Injectable systems
responding to various stimuli such as light, chemical/physical reactions, as well
as temperature, have been investigated. The feasibility of tuning the degradation
and gelation time as well as the water content of the gels, coupled with the
mild gelation process and ability to deliver them in a minimally invasive manner,
make them potential protein and cell carrier vehicles. The most important
parameters that determine the suitabilit of the injectable gel for tissue engineer-
ing and drug delivery applications include rate of gelation, degradability, rate
of degradation, extent of water content, non-toxicity of the process, as well as
physical and mechanical properties of the gel. Each of the developed systems has
its own disadvantages and advantages depending on the end application. Even
though many of the gels show good biocompatibility, the ability of the gels to
mimic the viscoelastic properties of various tissues will be a crucial parameter
that will determine their applicability as tissue engineering scaffolds.
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