Tailoring PVA-Based Hydrogels for Scaffold Applications in Tissue Engineering: A Study of Ion Transport and Structural Properties

Abstract

Tissue engineering relies heavily on the development of biocompatible scaffolds that mimic the extracellular matrix (ECM) and support cell growth. Poly(vinyl alcohol) (PVA)-based hydrogels have emerged as promising candidates due to their hydrophilic nature, mechanical tunability, and biocompatibility. This thesis investigates the transport properties, water structuring, morphology, and mechanical behaviour of PVA hydrogels and their composites with natural polymers such as gelatin and sodium alginate, with the goal of optimising their use as scaffolds for tissue engineering applications.

Hydrogels were prepared using varying PVA molecular weights (Mn) ranging from 50,000 to 186,000 g/mol and polymer concentrations of 10, 15, and 20 wt%, and with and without natural polymer incorporation. Further modifications were introduced through coagulation, where hydrogels were treated with high salt solutions to induce structural changes. Comprehensive characterisation techniques including permeation studies, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and rheological analysis were employed to evaluate hydration levels, ion transport, pore morphology, and mechanical properties.

The results demonstrated that natural polymer incorporation, particularly gelatin, improved hydration and pore interconnectivity, promoting conditions favourable for nutrient diffusion and cell adhesion. Coagulation was shown to significantly alter hydrogel properties, enhancing mechanical stability in most formulations, though some sodium alginate-based hydrogels exhibited reduced robustness and anomalous ion transport behaviour.

Overall, the hydrogels displayed a balance of mechanical stability, hydration, and transport properties, with many formulations achieving characteristics comparable to native soft tissues. These findings provide a foundational understanding of how to tailor PVA-based hydrogels for scaffold applications in tissue engineering with a focus on ion transport, paving the way for future research focused on cellular integration, in vivo, and in vitro testing.

Date of Award	Feb 2025
Original language	English
Awarding Institution	Aston University
Supervisor	Anisa Mahomed (Supervisor) & Brian Tighe (Supervisor)