Tuning adhesion failure strength for tissue-specific applications

Abstract

Soft tissue adhesives are employed to repair and seal multiple organs, which range in both tissue surface chemistry and mechanical challenges during organ function. This complexity motivates the development of tunable adhesive materials with high resistance to uniaxial or multiaxial loads dictated by a specific organ environment. Co-polymeric hydrogels comprising aminated star polyethylene glycol and dextran aldehyde (PEG:dextran) are materials exhibiting physicochemical properties that can be modified to achieve this organ-and tissue-specific adhesion performance. Here we report that resistance to failure under specific loading conditions, as well as tissue response at the adhesive material-tissue interface, can be modulated through regulation of number and density of adhesive aldehyde groups. We find that atomic force microscopy (AFM) can characterize material aldehyde density available for tissue interaction, and in this way enable rapid, informed material choice. Further, the correlation between AFM quantification of nanoscale unbinding forces with macroscale measurements of adhesion strength by uniaxial tension or multiaxial burst pressure allows for the design of materials with specific cohesion and adhesion strengths. However, failure strength alone does not predict optimal in vivo reactivity. Thus, we demonstrate that the development of adhesive materials is enabled significantly when experiments are integrated along lengthscales to consider organ chemistry and mechanical loading states concurrently with adhesive material properties and tissue response.

Single and dual crosslinked oxidized methacrylated alginate/PEG hydrogels for bioadhesive applications

“…The overall strategy for dual-crosslinked OMA/PEG hydrogel bioadhesive formation is showed in Figure 1. The first crosslinking networks are formed by Schiff base reaction between aldehyde groups of the OMA and amines of the 8-arm PEG and provide the cohesive force that stabilizes the bioadhesive into a hydrogel [12, 18, 26]. The second crosslinking networks formed by photocrosslinking the methacrylate groups of OMA may provide an improved resistance to shear or tensile loading and excessive swelling.…”

“…As the oxidation level of polysaccharides increased, the modulus and adhesion strength of many of the bioadhesives increased [12, 14, 17, 18] due to the greater number of reactive aldehyde groups available for crosslinking. However, higher degrees of polysaccharide oxidation result in rapid degradation that might be unsuitable for most in vivo bioadhesive applications as rapid degradation can lead to loss of adhesion capacity and mechanical stability of bioadhesives [18]. An ideal bioadhesive would allow for rapid and robust adhesion to maintain wound integrity during biological healing processes, and ease of handling to permit application in a precisely controlled manner.…”

Polymer films with surfaces unmodified and modified by non-thermal plasma as new substrates for cell adhesion

“…The synthesis of new polymers that interact favorably with organisms, allowing cell adhesion may, for example, encourage the replacement of damaged organs or tissues [1][2][3][4][5].…”

Isoreactive Manipulation of Bioadhesive Polymers Impacts Tissue-Specific Interactions

“…While beyond the scope of the present study, the tissue-present amine group distribution could be quantified with the use of functional atomic force microscopy (fAFM). [16] [22] Indeed, future studies using fAFM on soft tissue and material surfaces for the purpose of quantifying and comparing the spacing/density of the Figure 4. In-vitro cell response.…”

“…[15] [16] These studies have demonstrated that polymer-based adhesive bond formation with various soft tissues is concurrently modulated by the mode of chemical bond formation and the targeted tissue surface characteristics. Moreover, the sensitivity of polymer adhesion strength to increasingly bioreactive material formulations varies with target tissue type, suggesting that in addition to careful selection of bioreactive group chemistry, optimization of bioreactive group content available for adhesive bond formation must be done on a tissue-specific basis.…”