| dc.description.abstract | The design of polymeric biomaterials for soft tissue adhesion is of great interest in applications such as skin adhesives for surgical applications, hydrogels for tissue regeneration and mucoadhesives for dental adhesion; in these applications careful regulation of the interactions between the material and soft tissue is vital. In order to promote adhesion to soft tissues, a greater understanding of the relationship between polymer chemistry and adhesion mechanisms at different length scales is required. This work investigated the adhesion of protein resistant and weak polyelectrolyte brushes to epithelial cell monolayers (primary keratinocytes and HaCaT cells), soft tissues (porcine epicardium and keratinized gingiva) and a range of substrates with defined surface chemistry (self-assembled monolayers (SAMs)). Testing was carried out via colloidal probe-based atomic force microscopy (AFM). Poly(acrylic acid) (PAA) hydrogels were developed through different functionalisation (conjugation with a primary amine or bromoalkane) and crosslinking strategies (chemical or physical) and their adhesion to soft tissues was investigated via tensile and lap shear testing. Nanoscale adhesion assays reveal the complex balance of interactions (electrostatic, Van der Waals interactions and hydrogen bonding) that regulate the adhesion of weak polyelectrolyte brushes. In turn, studies on cell monolayers highlighted the importance of the glycocalyx in regulating non-specific adhesions. Alongside these studies, macroscale tests further confirmed the effect of tissue biochemistry on adhesion, with thiyl-bonded gels displaying particularly strong adhesion. Overall, this work clearly demonstrates the complex nature of soft tissue adhesion involving non-specific interactions and covalent bonding, which are further regulated by the mechanical properties of the bulk biomaterial, the soft tissue
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and their interface. It is hoped that this multi-scale insight into the adhesion of polymers to cells/tissues will further advance the understanding of soft tissue adhesion, enabling the more effective and rational design of a novel generation of bioadhesives. | en_US |
