Protein encapsulation in biodegradable polymeric nanoparticles: morphology, fluorescence behaviour and stem cell...

Area of Science:

• Biomaterials Science
• Nanotechnology
• Cell Biology

Background:

• Biodegradable polymers are essential for drug delivery and tissue engineering.
• Encapsulating proteins in nanoparticles protects them and facilitates cellular uptake.
• Fluorescently labeled proteins allow for tracking and studying cellular interactions.

Purpose of the Study:

• To synthesize and characterize novel biodegradable polymeric nanoparticles (NPs).
• To load these NPs with fluorescein isothiocyanate-bovine serum albumin (FITC-BSA).
• To evaluate the cellular uptake and retention of FITC-BSA-loaded NPs in stem cells.

Main Methods:

• Synthesis of poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles using the double emulsion solvent evaporation method.
• Characterization of nanoparticle size, shape, and aggregation state.
• Fluorescence spectroscopy (steady-state and time-resolved) to probe the protein environment.
• In vitro assessment of nanoparticle internalization and retention in stem cells.

Main Results:

• Spherical, uniformly sized biodegradable polymeric NPs were successfully synthesized without aggregation after drying.
• Fluorescence measurements confirmed the successful encapsulation of FITC-BSA and provided insights into the protein's nanoscale environment.
• FITC-BSA-loaded NPs demonstrated rapid internalization by stem cells.
• A notable percentage of stem cells (25%) remained slightly positive for the fluorescent marker after 28 days, indicating sustained presence.

Conclusions:

• Biodegradable PLGA nanoparticles are effective carriers for protein encapsulation (FITC-BSA).
• The synthesized nanoparticles possess favorable characteristics for cellular applications, including good stability and rapid uptake.
• These nanoparticles show promise for applications requiring intracellular delivery and long-term tracking in stem cells.