Arrays of Biocompatible and Mechanically Robust Microchambers Made of Protein-Polyphenol-Clay Multilayer Films

Area of Science:

• Biomaterials Science
• Materials Engineering
• Nanotechnology

Background:

• Growing demand for biocompatible, mechanically robust microcompartments for sensing and controlled release.
• Need for advanced materials in drug delivery and biomedical applications.

Purpose of the Study:

• To develop and characterize a novel biocompatible composite material, protein-polyphenol-clay (PPC) multilayer film, for microchambers.
• To compare the mechanical properties and biocompatibility of PPC microchambers with synthetic polyelectrolyte multilayer films (PSS-PAH).

Main Methods:

• Fabrication of protein-polyphenol-clay (PPC) and poly(styrenesulfonate)-poly(allylammonium) (PSS-PAH) multilayer films into microchambers.
• Mechanical characterization using nanoindentation under uniaxial compression.
• Biocompatibility testing using an ex vivo 3D human skin reconstruct model with drug-loaded microchambers.

Main Results:

• PPC microchambers exhibited lower Young's modulus (166 ± 53 MPa) but higher elastic energy absorption capacity (2.4 ± 1.0 MPa) compared to PSS-PAH microchambers (245 ± 52 MPa and 2.0 ± 1.3 MPa, respectively).
• PPC microchambers demonstrated no toxicity in the 3D human skin model.
• PSS-PAH microchambers reduced epidermal cell density and affected epidermal-dermal attachment, while both materials impacted skin cell differentiation but not proliferation.

Conclusions:

• Protein-polyphenol-clay (PPC) multilayer films provide a promising biocompatible and mechanically robust material for microchamber fabrication.
• PPC microchambers are a safer alternative to PSS-PAH microchambers for potential applications in controlled drug release, showing no adverse effects on skin tissue.
• The study suggests that microchamber arrays may influence skin physiology through effects on transpiration, normoxia, and moisture exchange rather than direct barrier function impairment.