# Characterization of a Novel POx-Based Adhesive Powder for Obliterating Dead Spaces After Surgery

## TL;DR

A new adhesive powder based on NHS-POx shows strong potential for eliminating surgical dead spaces due to its adhesive strength, biocompatibility, and controllable degradation.

## Contribution

A novel NHS-POx-based adhesive powder is developed with tunable properties for dead space obliteration in surgical settings.

## Key findings

- The adhesive powder showed minimal swelling and rapid crosslinking, which can be modulated by pH, surfactant, and particle size.
- Adhesive strength of the powder exceeded that of commercial fibrin glue in tensile and shear tests.
- Prototypes with buffer and surfactant lost adhesive force after 14 days, while others retained it, indicating controllable degradation.

## Abstract

Surgical dead spaces are challenging to handle with current preventive methods. Tissue adhesives show promise in obliterating ‘dead spaces’, but the drawbacks of currently available adhesives prevent them from being used for dead space elimination. An adhesive powder based on N-Hydroxysuccinimide-poly(2-oxazoline), NHS-POx, combines robust adhesive strength in moist environments with favorable biocompatibility and biodegradability, which makes this an interesting candidate for eliminating spaces that remain between tissues after surgery. The current study evaluates the swelling, crosslinking speed, and degradation properties of this novel tissue adhesive. These results were then used to design multiple adhesive variants differing in pH, surfactant addition, and particle size, which were subsequently examined based on their wetting rates, adhesive strength, and durability. The powder displayed minimal swelling and rapid crosslinking properties, by which the latter could be increased by a basic buffer or surfactant addition and reduced by increasing particle size. The wetting rate of the powder increased when a surfactant (Pluronic F68) was added to the mix. The adhesive strength, as measured by tensile and shear strength measurements of different prototypes of the adhesive powder, was significantly better than that of a commercially available fibrin glue. The addition of both buffer and Pluronic F68 led to a breakdown of adhesive force after 14 days of incubation, while the prototype containing neither buffer nor Pluronic F68 still had measurable adhesive force after 14 days of incubation. The current study results display several characteristics of the NHS-POx-based tissue adhesive that are favorable for tissue approximation, preventing the occurrence of dead spaces. The most effective and usable adhesive prototype will be identified in further ex vivo and in vivo animal model studies.