Neurosurgical Applications of a Novel Tough Adhesive Biomaterial

Introduction: Cerebrospinal fluid (CSF) leaks complicate up to 30% of skull base operations. Current surgical adhesives for CSF leak repair are limited by poor adhesion in dynamic and aqueous environments and an inability to reconstruct large cranial defects that span multiple types of tissue. In contrast, tough adhesives are a novel hydrogel coated with an adhesive bridging polymer that provides high performance as a sealant within biological fluids. This novel technology demonstrates extraordinary mechanical toughness, capacity to repeatedly withstand significant strain, and the ability to bind strongly to wet surfaces. However, their application to dural tissue has not been investigated. The purpose of this study was to investigate the use of this novel biomaterial for dural reconstruction and CSF leak prevention. We hypothesized that tough adhesives will exhibit a greater burst pressure compared with existing commercial sealants.

Methods: We evaluated the effectiveness of the tough adhesives to withstand high pressures using a porcine cadaveric model with a dural defect (3-mm diameter, n = 6). Testing was conducted with an established burst pressure test setup. We recorded the maximum burst pressure achieved prior to the loss of integrity of the biomaterial graft or its detachment from the underlying dura ([Fig. 1]). We further investigated its effectiveness after 5 days of bathing within an artificial CSF environment of variable physiologic (37°C, n = 5) and supraphysiologic (45°C, n = 5) temperatures.

Results: The tough adhesive provided strong adhesion to cadaveric porcine dura (burst pressure: 140.2 ± 23.7 mm Hg), with several-fold higher strength than existing commercial sealants ([Fig. 2]). The tough adhesive also maintained its integrity under variable thermochemical conditions after prolonged exposure to an aqueous CSF environment. Burst pressures demonstrated similar burst points at 37°C and 45°C (37C burst pressure: 71.59 ± 44.70 mm Hg; 45°C burst pressure: 78.30 ± 57.92 mm Hg, p = 0.843; [Fig. 3]).

Conclusion: We present a novel biomaterial with unique mechanical properties suited to complex neurosurgical reconstruction applications. In vitro testing demonstrates its ability to maintain integrity under supraphysiologic temperatures and with higher performance than existing commercial solutions. Ongoing work will focus on assessing the long-term durability and biocompatibility of this material within the central nervous system. Additional potential applications include wound closure, hemostasis, and scaffolding for drug delivery and brachytherapy.

Fig. 1 Tough adhesive demonstrating strong adherence to porcine dura during peel-testing.

Fig. 2 Burst pressure performance of tough adhesives compared with two commonly used industry sealants.

Fig. 3 Burst pressure performance of tough adhesive control and control with 1-mm plastic backing run on day 0, as well as following a 5-day bath in artificial CSF at 37°C and 45°C.