Atomic Layer Deposition Processes: Versatile Platforms for Engineering ZnO-Chitosan Biointerfaces

Area of Science:

• Materials Science
• Biotechnology
• Surface Engineering

Background:

• Developing bio-multifunctional interfaces is crucial for advanced medical implants.
• Chitosan (CS) is a promising biomaterial, but its functionalization requires precise control.
• Atomic-scale deposition techniques offer new avenues for material modification.

Purpose of the Study:

• To engineer zinc-functionalized chitosan (CS) interfaces using atomic-scale techniques.
• To investigate the impact of different functionalization methods on material properties and biological response.
• To evaluate the potential of these interfaces for next-generation medical implants.

Main Methods:

• Utilized vapor phase metalation (VPM), multiple pulsed vapor phase infiltration (MPI), and O2 plasma-enhanced atomic layer deposition (PEALD) for zinc functionalization of CS.
• Characterized surface topography, structure, and elemental distribution using AFM, XRD, XPS, SEM, and EDX.
• Assessed physicochemical properties, cell proliferation (C2C12), antiseptic activity (E. coli, H. pylori), and in vivo immunomodulatory effects (angiogenesis, cytokine profiles).

Main Results:

• Homogeneous zinc distribution was confirmed across all methods.
• AFM revealed topographical changes, with MPI yielding high-surface-area nucleation.
• PEALD modification resulted in the highest interfacial energy and enhanced swelling.
• Functionalization method dictated semiconductor properties.
• CS-ZnO PEALD scaffolds demonstrated comparable C2C12 cell proliferation, tailored antiseptic activity, and promoted angiogenesis with a balanced immune response in vivo.
• Stable anti-inflammatory IL-10 and near-basal pro-inflammatory IL-6 levels were observed in vivo.

Conclusions:

• Atomic layer deposition (ALD)-based processes offer versatile control over zinc-functionalized chitosan (CS) interfaces.
• The CS-ZnO PEALD scaffolds exhibit immunomodulatory properties, promoting angiogenesis and a balanced immune response.
• These findings support the development of next-generation intelligent medical implants and bio-integrated electronics.