Biopolymeric injectable
hydrogels are promising biomaterials
for
myocardial regeneration applications. Besides being biocompatible,
they adjust themselves, perfectly fitting the surrounding tissue.
However, due to their nature, biopolymeric hydrogels usually lack
desirable functionalities, such as antioxidant activity and electrical
conductivity, and in some cases, mechanical performance. Protein nanofibrils
(NFs), such as lysozyme nanofibrils (LNFs), are proteic nanostructures
with excellent mechanical performance and antioxidant activity, which
can work as nanotemplates to produce metallic nanoparticles. Here,
gold nanoparticles (AuNPs) were synthesized in situ in the presence
of LNFs, and the obtained hybrid AuNPs@LNFs were incorporated into
gelatin-hyaluronic acid (HA) hydrogels for myocardial regeneration
applications. The resulting nanocomposite hydrogels showed improved
rheological properties, mechanical resilience, antioxidant activity,
and electrical conductivity, especially for the hydrogels containing
AuNPs@LNFs. The swelling and bioresorbability ratios of these hydrogels
are favorably adjusted at lower pH levels, which correspond to the
ones in inflamed tissues. These improvements were observed while maintaining
important properties, namely, injectability, biocompatibility, and
the ability to release a model drug. Additionally, the presence of
AuNPs allowed the hydrogels to be monitorable through computer tomography.
This work demonstrates that LNFs and AuNPs@LNFs are excellent functional
nanostructures to formulate injectable biopolymeric nanocomposite
hydrogels for myocardial regeneration applications.