Synthesis and characterization of enzymatically active micrometer protein-capsules

Area of Science:

• Biochemistry
• Materials Science
• Cell Biology

Background:

• Oxygen toxicity is a concern with artificial oxygen carriers.
• Enzyme encapsulation offers a potential solution for controlled delivery and activity.
• Albumin is explored as a biocompatible wall material for enzyme encapsulation.

Purpose of the Study:

• To develop a general method for encapsulating enzymes, using catalase as an example.
• To create biochemically active sub-micrometer particles to mitigate oxygen toxicity.
• To evaluate the efficacy and safety of encapsulated catalase in cell culture.

Main Methods:

• Enzyme encapsulation using albumin as the wall material.
• Preparation of sub-micrometer particles containing catalase.
• Cell culture experiments to assess catalase capsule activity and toxicity in the presence and absence of hydrogen peroxide.

Main Results:

• Catalase capsules showed no harmful activity without peroxides.
• Low to medium doses of capsules exacerbated cell damage in the presence of hydrogen peroxide.
• High doses of capsules (>0.05 vol%) completely prevented cell disruption by 5 mM hydrogen peroxide and reduced damage by up to 90% at higher concentrations.
• The overall activity of the prepared catalase capsules was determined to be >1900 U mL⁻¹ vol%⁻¹.

Conclusions:

• Encapsulated catalase retains enzymatic activity.
• Albumin-encapsulated catalase particles demonstrate dose-dependent protective effects against hydrogen peroxide-induced cellular damage.
• This encapsulation method provides a viable strategy for utilizing enzymes like catalase in biological applications where peroxide or oxygen management is critical.