Morphological evaluation of bioartificial hydrogels as potential tissue engineering scaffolds

Abstract

Poly(vinyl alcohol) hydrogels prepared by freeze-thawing procedure represent synthetic systems widely investigated as non-biodegradable scaffolds for tissue regeneration. In order to improve the biocompatibility properties of pure poly(vinyl alcohol) (PVA) hydrogels, blends of PVA with different biological macromolecules, such hyaluronic acid, dextran, and gelatin were prepared and used to produce "bioartificial hydrogels". The porosity characteristics of these hydrogels were investigated by scanning electron microscopy and mercury intrusion porosimetry. The morphology of bioartificial hydrogels was evaluated and compared with that of pure PVA hydrogels. In particular the effect exerted by each biological component on pore size and distribution was investigated. The obtained results indicate that when a natural macromolecule is added to PVA the internal structure of the material changes. A small amount of biopolymer induces the structural elements of PVA matrix to take on a well evident lamellar appearance and an apparent preferential orientation. Comparing the results of SEM and mercury intrusion porosimetry it was concluded that hydrogels containing 20% of biological component have the most regular structure and at the same time the lowest total porosity. On the contrary samples with the highest content of natural polymer (40%) show the less regular structure and the highest total porosity.

Silk fibroin/hyaluronan scaffolds for human mesenchymal stem cell culture in tissue engineering

“…Pore sizes were in the range of 100-400 μm, an optimal size for tissue engineering applications [41]. This outcome contrasts with the non-porous structure of plain SF scaffolds and with the small pores observed in polyvinylalcohol/HA scaffolds as prepared by Cascone et al [39].…”

“…This approach was based on the work of Cascone et al who showed that porous matrices (pore size 10-50 μm) may be prepared just by freeze-drying a structural polymer (polyvinylalcohol) with a blender (HA or gelatine) [39]. An interesting feature of this method is that it avoids the use of conventional porogens and the associated harsh manufacturing protocols that are typically required to extract them, such as leaching with aqueous or organic media [8,40].…”

Effect of Cryogenic Treatment on the Rheological Properties of Gelatin Hydrogels

“…(16)(17)(18) Blends of poly(vinyl alcohol) with different biological macromolecules, such as hyaluronic acid, dextran and gelatin were applied to produce bioartificial hydrogels functioning as potential tissue engineering scaffolds. (19) In the present work, a cryogenic treatment is applied on gelatin for biomedical use. Gelatin has been widely applied in medicine as a wound dressing (22) and as an adhesive and absorbent pad for surgical use.…”

Nanoprobe Diffusion in Poly(Vinyl-alcohol) Gels and Solutions: Effects of pH and Dehydration

“…Examples of their use are engineering of tissue phantoms, designing extracellular matrices for tissue regeneration, and developing efficient drug delivery systems [1][2][3][4][5]. Understanding their structural and dynamical properties is therefore necessary, especially with the growing demand for hydrogels tailored for specific applications.…”