Engineered Microalgal Extracellular Vesicles for Enhancing Mitochondrial Homeostasis in Radiodermatitis Prevention.

Area of Science:

• Biomaterials Science
• Nanotechnology
• Drug Delivery

Background:

• Radiodermatitis is a common side effect of radiotherapy, causing cellular oxidative stress and inflammation.
• Astaxanthin (AST) has therapeutic potential but suffers from poor solubility and stability.
• Microalgal extracellular vesicles (EVs) offer a biocompatible platform for drug delivery.

Purpose of the Study:

• To engineer astaxanthin-loaded microalgal EVs (SP-EVs@AST) for enhanced solubility and stability.
• To develop a hydrogel-based skin radiation protection dressing incorporating SP-EVs@AST.
• To evaluate the efficacy and safety of the SP-EVs@AST hydrogel for preventing radiation-induced skin injury.

Main Methods:

• Isolated EVs from *Spirulina platensis* (SP) and loaded them with astaxanthin (AST).
• Formulated a hydrogel dressing using aldehyde-functionalized hyaluronic acid (HA-CHO) and carboxymethyl chitosan (CMCS) with SP-EVs@AST.
• Assessed the protective effects of SP-EVs@AST against radiation-induced cellular damage and evaluated the hydrogel's performance in vivo.

Main Results:

• Engineered SP-EVs@AST demonstrated enhanced AST solubility and stability, retaining SP-EVs' biological activity.
• SP-EVs@AST effectively alleviated oxidative stress, restored mitochondrial function, and reduced inflammation in radiation-damaged cells.
• The SP-EVs@AST hydrogel dressing provided sustained release, protected skin from radiation injury, and showed long-term safety.

Conclusions:

• Engineered microalgal EVs serve as an effective carrier for poorly soluble drugs like AST.
• The SP-EVs@AST hydrogel dressing presents a promising strategy for radiodermatitis prevention and targeted drug delivery.
• This approach highlights the potential of microalgal EVs in advanced biomedical applications.