A high throughput method for quantification of cell surface bound and internalized chitosan nanoparticles.

Area of Science:

• Biomaterials Science
• Nanotechnology
• Cell Biology

Background:

• Chitosan is a widely used polymer for drug delivery due to its solubility and mild formulation properties.
• Accurate quantification of internalized chitosan nanoparticles (NPs) is essential for evaluating drug delivery efficacy, particularly for macromolecules where cellular uptake is size and charge-dependent.
• Existing methods may not precisely differentiate between cell-surface bound and internalized NPs.

Purpose of the Study:

• To develop a simple, rapid method for quantifying internalized chitosan NPs.
• To differentiate and quantify cell surface-bound versus internalized chitosan NPs.
• To enable accurate assessment of chitosan-based nano-formulations for drug delivery.

Main Methods:

• Exploited the specific affinity of fluorescein isothiocyanate-tagged wheat germ agglutinin (WGA-FITC) for chitosan.
• Developed a method to distinguish and quantify NPs bound to the cell surface from those internalized within cells.
• Validated the method across various cell lines, NP sizes (25 and 150nm), and low NP concentrations (20μg/mL).

Main Results:

• Successfully differentiated and quantified cell surface-bound and internalized chitosan NPs.
• Enabled calculation of corrected NP uptake by accounting for cell surface-bound particles.
• Demonstrated applicability across diverse cell lines and nanoparticle characteristics.

Conclusions:

• The developed WGA-FITC method provides accurate evaluation of chitosan NP uptake.
• This method is vital for assessing chitosan-based nanomedicines.
• It can guide the modification of NPs for enhanced cellular internalization and improved drug delivery.