Property determinants of dextran:polyethylene glycol adhesive sealants

Abstract

Internal surgical intervention necessitates the intentional wounding of tissue. In certain clinical procedures, the desired wound healing response requires the use of closure techniques, such as suturing or stapling of disjoined tissues. Risk factors associated with these techniques are largely attributed to the discrete nature of the mechanical forces arising in the tissues. Adhesive sealants can mitigate risk by imparting a continuous stress distribution to tissues upon closure, as opposed to destructive stress concentrations. A novel class of dextran:polyethylene glycol hydrogels are a potential alternative to the limited selection of available adhesive sealants. Multiple compositional variations are available for both the dextran and polyethylene glycol components, making a wide range of clinically relevant material properties achievable. Key material properties determining sealant efficacy include hydration and degradation in an aqueous medium, elastic modulus, adhesion strength to tissue, and biocompatibility. Relationships between these pertinent properties and available compositional variations are determined for dextran:polyethylene glycol materials.

(cont.) Gravimetric, mechanical and biological testing reveal the following compositional determinants of material properties in dextran:polyethylene glycol copolymers: constituent molecular complexity dictates material hydration and degradation, solid content dictates elastic modulus, available aldehyde groups dictate adhesion strength, and material solid content and reactive group ratio dictate induced cell proliferation and cytotoxicity. Knowledge of these property determinants facilitates development of an optimal dextran:polyethylene glycol material in a small bowel resection model for adhesive sealants, and furthers the understanding of these complex copolymers for other sealant applications. Generalization of the identified property determinants to other material classes provides a vehicle for advancement of adhesive sealant technologies.