# Systematic design and optimisation of layer-by-layer nanocomposite coatings on three-dimensional porous scaffolds for enhanced mechanical performance in bone tissue engineering applications

## TL;DR

Researchers developed a method to strengthen porous bone scaffolds using nanocomposite coatings while preserving their structure.

## Contribution

A systematic framework for optimizing LbL assembly on porous scaffolds to balance mechanical strength and porosity.

## Key findings

- Optimized scaffolds showed a 260-fold increase in elastic modulus to 23.55 MPa.
- Maintained 78.2% ± 1.24 porosity with interconnected pore structure.
- Used DoE and RSM to identify key variables in LbL assembly.

## Abstract

Structural integrity and interconnected porosity are essential design criteria for bone tissue scaffolds. This study presents the optimisation of electrostatic layer-by-layer (LbL) assembly conditions for nanocomposite multilayer coatings on highly porous polyurethane scaffold templates, relevant to bone scaffold applications. Mechanically robust LbL coatings were applied to enhance the balance between scaffold porosity and mechanical strength. A design of experiments (DoE) approach using response surface methodology (RSM) was conducted in two stages to systematically optimise both LbL process parameters and nanocomposite composition. The optimised scaffolds exhibited a 260-fold increase in elastic modulus, from 0.09 MPa (uncoated) to 23.55 MPa, while maintaining a highly interconnected pore structure with 78.2% ± 1.24 porosity. These results establish a systematic framework for tuning LbL assembly on porous scaffolds towards bone tissue engineering.

Systematic optimisation of composition and process parameters for Layer-by-Layer assembly deposition of nanocomposite films on porous templates to identify variables governing multilayer formation, mechanical reinforcement, and porosity.