Loading PEG-catalase into filamentous and spherical polymer nanocarriers

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Enzyme Engineering

Background:

• Enzyme encapsulation in nanocarriers is crucial for therapeutic applications.
• Protecting enzymes from degradation, particularly proteases, remains a challenge.
• Polyethylene glycol (PEG)ylation is a common strategy to improve protein stability and circulation time.

Purpose of the Study:

• To investigate if PEGylation of catalase enhances its encapsulation within diblock copolymer nanocarriers (PNCs).
• To determine if PEGylated catalase exhibits increased resistance to protease degradation compared to native catalase when encapsulated.
• To assess the impact of nanocarrier geometry on enzyme loading and stability.

Main Methods:

• Utilized a freeze-thaw modified double emulsion technique to encapsulate catalase and PEG-catalase into PEG-PLA nanocarriers.
• Monitored enzyme activity via spectrophotometry.
• Employed isotope labeling for quantifying loading efficiency, protease resistance, and in vivo blood clearance in mice.

Main Results:

• PEGylation of catalase improved its encapsulation and protease resistance within both filamentous and spherical PNCs compared to native catalase.
• While free PEG-catalase had longer circulation times than free catalase, both were equally susceptible to proteolysis.
• Isotope tracing confirmed similar blood levels for encapsulated PEG-catalase and free PEG-catalase in mice.

Conclusions:

• PEGylation significantly enhances the loading of active catalase into polymer nanocarriers.
• PEGylated catalase demonstrates improved resistance to protease degradation when encapsulated within nanocarriers.
• This study highlights the benefits of PEGylation for creating more robust enzyme-loaded nanocarrier systems.