The excessive reactive oxygen species (ROS) and hypoxia deteriorate the inflammation‐related diseases such as myocardial infarction (MI), and thereby deter the normal tissue repair and recovery and further lead to severe fibrosis and malfunction of tissues and organs. In particular, the MI has become one of the leading causes of death nowadays. In this study, a novel type of injectable hydrogel with dual functions of ROS scavenging and O2 generating is fabricated for MI treatment in vivo. The hydrogel is formed within 3 s from the synthetic ROS‐cleavable hyperbranched polymers and methacrylate hyaluronic acid (HA‐MA) under UV‐irradiation. Addition of biocompatible and applicable catalase in vivo enables the further transition of H2O2, a major type of ROS, to O2 and H2O. Results of rat MI model demonstrate that this hydrogel can significantly remove excessive ROS, inhibit cell apoptosis, increase M2/M1 macrophage ratio, promote angiogenesis, reduce infarcted area, and improve cardiac functions. With the appropriate degradation rate, simple structure and composition without cell seeding, and very excellent MI therapeutic effect, this ROS scavenging and O2 generating hydrogel has a great promise to be applied clinically.
Regeneration
and functional recovery of peripheral nerves remain formidable due
to the inefficient physical and chemical cues in the available nerve
guidance conduits (NGCs). Introducing micropatterns and bioactive
substances into the inner wall of NGCs can effectively regulate the
behavior of Schwann cells, the elongation of axons, and the phenotype
of macrophages, thereby aiding the regeneration of injured nerve.
In this study, linear micropatterns with ridges and grooves of 3/3,
5/5, 10/10, and 30/30 μm were created on poly(d,l-lactide-co-caprolactone) (PLCL) films following
with surface aminolysis and electrostatic adsorption of graphene oxide
(GO) nanosheets. The GO-modified micropatterns could significantly
accelerate the collective migration of Schwann cells (SCs) and migration
of SCs from their spheroids in vitro. Moreover, the SCs migrated directionally
along the stripes with a fastest rate on the 3/3-GO film that had
the largest cell adhesion force. The neurites of N2a cells were oriented
along the micropatterns, and the macrophages tended to differentiate
into the M2 type on the 3/3-GO film judged by the higher expression
of Arg 1 and IL-10. The systematic histological and functional assessments
of the regenerated nerves at 4 and 8 weeks post-surgery in vivo confirmed
that the 3/3-GO NGCs had better performance to promote the nerve regeneration,
and the CMAP, NCV, wet weight of gastrocnemius muscle, positive S100β
and NF200 area percentages, and average myelinated axon diameter were
more close to those of the autograft group at 8 weeks. This type of
NGCs thus has a great potential for nerve regeneration.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.