Determination of pore size distribution at the cell-hydrogel interface

Area of Science:

• Biomaterials Science
• Cell Biology
• Materials Science

Background:

• Analyzing pore size distribution at the cell-hydrogel interface is crucial for understanding cellular growth and microenvironment stimuli.
• Current methods for assessing biomaterial porosity often lack quantitative data on nano-interface textural properties.

Purpose of the Study:

• To develop and validate a novel methodology for quantifying pore size distribution at the cell-hydrogel interface.
• To investigate the impact of HepG(2) cell growth on alginate hydrogel matrix structure and porosity.

Main Methods:

• A new image analysis technique was employed to estimate the shortest distance between points in hydrogel fibril networks from TEM images.
• Pore size distribution was determined at the cell-hydrogel interface for HepG(2) cells in varying alginate concentrations (0.8% and 1.4% w/v).
• Results were validated by comparison with nitrogen physisorption measurements.

Main Results:

• The developed method accurately determined pore size distribution and matrix depth modified by cell growth.
• HepG(2) cells in 0.8% alginate hydrogels showed increased pore coarsening up to 40 nm deep after three days, most prominent within 20 nm of the interface.
• This pore coarsening effect was less pronounced in 1.4% alginate hydrogels.

Conclusions:

• The proposed method provides quantitative insights into hydrogel matrix radial deformation caused by cell growth.
• This technique allows for the characterization of pore size distribution changes around cells, vital for various applications.
• The findings highlight the influence of alginate concentration on cell-induced matrix modification and pore structure.