A Polymeric Nanocarrier Platform for Rapid and Precise Fatty Acid Tracing in Cells

Area of Science:

• Metabolic Engineering
• Biotechnology
• Analytical Chemistry

Background:

• Stable isotope tracing is crucial for understanding metabolic pathways.
• Fatty acid tracers like U-¹³C-palmitate are used to study lipid metabolism.
• Current methods using BSA conjugates face limitations in tracer delivery, including transport bottlenecks, toxicity, and immunogenicity.

Purpose of the Study:

• To develop and evaluate biodegradable nanocarriers as an improved delivery system for hydrophobic stable isotope tracers.
• To benchmark the performance of nanocarrier-based delivery against traditional BSA conjugation for U-¹³C-palmitate tracing.

Main Methods:

• Development of biodegradable nanocarriers for hydrophobic tracer delivery.
• Utilizing metabolomics and lipidomics to compare nanocarrier-mediated delivery with BSA-conjugated U-¹³C-palmitate.
• Analysis of tracer uptake, intracellular accumulation, depletion kinetics, and metabolic incorporation.

Main Results:

• Nanocarriers achieved higher and faster intracellular accumulation of U-¹³C-palmitate compared to BSA conjugates.
• Nanocarrier-delivered tracers showed predictable first-order depletion kinetics, indicating efficient metabolism.
• BSA delivery resulted in delayed or biphasic tracer depletion, suggesting transport limitations and reduced bioavailability.
• ¹³C-labeled fatty acids and complex lipids were detected, confirming tracer incorporation into metabolic networks without material-induced aberrations.

Conclusions:

• Biodegradable nanocarriers significantly enhance the delivery and metabolic utilization of stable isotope tracers.
• This nanocarrier platform overcomes the limitations associated with BSA-mediated delivery, offering improved efficiency and predictability.
• The versatile and customizable nanocarrier system holds promise for advanced metabolic tracing in complex biological systems.