Conjugated Network Supporting Highly Surface-Exposed Ru Site-Based Artificial Antioxidase for Efficiently Modulating...

Area of Science:

• Materials Science
• Biomedical Engineering
• Photochemistry

Background:

• Solar dermatitis is an acute skin radiation burn caused by excessive ultraviolet B (UVB) exposure.
• Reactive oxygen species (ROS) accumulation from UVB radiation drives skin inflammation and cell damage.
• Current treatments for solar dermatitis often focus on symptom management rather than addressing the root cause of ROS accumulation.

Purpose of the Study:

• To design and fabricate a novel π-conjugated network polyphthalocyanine supporting a highly surface-exposed Ru active site-based artificial antioxidase (HSE-PPcRu).
• To evaluate the efficacy of HSE-PPcRu in scavenging ROS, modulating the microenvironment, and alleviating solar dermatitis.
• To investigate the molecular mechanisms underlying HSE-PPcRu's protective effects in photodamaged skin cells and *in vivo* models.

Main Methods:

• Fabrication of a π-conjugated network polyphthalocyanine with a highly surface-exposed Ru active site (HSE-PPcRu).
• In vitro studies using photodamaged human keratinocyte cells to assess ROS scavenging, DNA damage prevention, apoptosis suppression, and modulation of MAPK and NF-κB signaling pathways.
• In vivo animal experiments to evaluate antioxidant and anti-inflammatory effects by analyzing key signaling molecules and cytokine expression.

Main Results:

• HSE-PPcRu demonstrated excellent ROS-scavenging, antioxidant, and anti-inflammatory capabilities.
• In vitro, HSE-PPcRu modulated MAPK and NF-κB pathways, prevented DNA damage, suppressed apoptosis, and reduced pro-inflammatory cytokine secretion in keratinocytes.
• *In vivo*, HSE-PPcRu reversed p38 and JNK activation, inhibited COX-2, IL-6, IL-8, and TNF-α expression, confirming its therapeutic potential.

Conclusions:

• HSE-PPcRu effectively alleviates solar dermatitis by catalytically scavenging ROS and modulating the skin's microenvironment.
• The study provides a promising strategy for developing advanced artificial antioxidases with highly surface-exposed active sites for treating UV-induced skin damage.
• This work highlights the potential of engineered nanomaterials in addressing oxidative stress-related inflammatory skin conditions.