Nanoscale eluting coatings based on alginate/chitosan hydrogels.

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Drug Delivery Systems

Background:

• Localized delivery of bioactive molecules at the implant/tissue interface is crucial for effective wound healing and biointegration.
• Thin surface coatings offer localized delivery but have limited reservoir capacity for sustained release.
• Alginate/chitosan hydrogels provide a hydrophilic, water-insoluble platform for controlled biomolecule elution.

Purpose of the Study:

• To develop and characterize nanoscale eluting hydrogel coatings for localized bioactive molecule delivery.
• To investigate the release kinetics and influencing factors of model molecules from alginate/chitosan coatings.
• To demonstrate the potential of these coatings for enhanced wound healing and biointegration.

Main Methods:

• Fabrication of alginate/chitosan hydrogel coatings on silicon wafers and paper substrates.
• Characterization of coating morphology, uniformity, and thickness using SEM, AFM, and ellipsometry.
• Quantification of model molecule release (FD, albumin, rhodamine) using various release media and kinetic models.

Main Results:

• Uniform, conformal hydrogel coatings (approx. 120 nm thickness, 3.0 nm roughness) were achieved on silicon wafers.
• Sustained release of fluorescein isothiocyanate dextran (FD) was observed, dependent on molecular weight, medium, charge, and surface roughness.
• High yields (90% for FD 70, 75% for FD 2000) were achieved within 26 days in simulated body fluid, demonstrating concurrent elution capability.

Conclusions:

• Alginate/chitosan hydrogel coatings serve as effective nanoscale delivery systems for bioactive molecules.
• The coatings provide sustained, controlled release, crucial for the initial stages of wound healing and biointegration.
• This technology holds promise for improving implant performance and patient outcomes through enhanced localized therapy.