Physical and biological properties of a novel siloxane adhesive for soft tissue applications

• Published in: Journal of biomaterials science. Polymer ed. 2005-01, Vol.16 (4), p.449-472
• Main Authors: Wilson, D. J., Chenery, D. H., Bowring, H. K., Wilson, K., Turner, R., Maughan, J., West, P. J., Ansell, C. W. G.
• Format: Article
• Language: English
• Subjects: Acrylamides - chemistry; ADHESIVES; Adhesives - chemistry; Aging; Analysis of Variance; Animals; BIOCOMPATIBILITY; Biocompatible Materials - chemistry; Bucrylate - chemistry; Cartilage - drug effects; Cartilage - metabolism; Cell Adhesion; Chondrocytes - metabolism; Culture Media, Conditioned - pharmacology; CYANOACRYLATES; Formaldehyde - chemistry; Gelatin - chemistry; IMAGING; Models, Chemical; Phosphates - chemistry; Polymers - chemistry; Propylamines - chemistry; RAMAN; Resorcinols - chemistry; Sheep; Silanes - chemistry; SILOXANES; Siloxanes - chemistry; Spectrometry, X-Ray Emission; Spectrophotometry; Spectrophotometry, Infrared; Spectrum Analysis, Raman; Temperature; Time Factors; XPS
• ISSN: 0920-5063; 1568-5624
• DOI: 10.1163/1568562053700200

The aim of this study was to investigate the adhesive properties of an in-house amino-propyltrimethoxysilane-methylenebisacrylamide (APTMS-MBA) siloxane system and compare them with a commercially available adhesive, n-butyl cyanoacrylate (nBCA). The ability of the material to perform as a soft tissue adhesive was established by measuring the physical (bond strength, curing time) and biological (cytotoxicity) properties of the adhesives on cartilage. Complementary physical techniques, X-ray photoelectron spectroscopy, Raman and infrared imaging, enabled the mode of action of the adhesive to the cartilage surface to be determined. Adhesion strength to cartilage was measured using a simple butt joint test after storage in phosphate-buffered saline solution at 37°C for periods up to 1 month. The adhesives were also characterised using two in vitro biological techniques. A live/dead stain assay enabled a measure of the viability of chondrocytes attached to the two adhesives to be made. A water-soluble tetrazolium assay was carried out using two different cell types, human dermal fibroblasts and ovine meniscal chondrocytes, in order to measure material cytotoxicity as a function of both supernatant concentration and time. IR imaging of the surface of cartilage treated with APTMS-MBA siloxane adhesive indicated that the adhesive penetrated the tissue surface marginally compared to nBCA which showed a greater depth of penetration. The curing time and adhesion strength values for APTMS-MBA siloxane and nBCA adhesives were measured to be 60 s/0.23 MPa and 38 min/0.62 MPa, respectively. These materials were found to be significantly stronger than either commercially available fibrin (0.02 MPa) or gelatin resorcinol formaldehyde (GRF) adhesives (0.1 MPa) (P < 0.01). Cell culture experiments revealed that APTMS-MBA siloxane adhesive induced 2% cell death compared to 95% for the nBCA adhesive, which extended to a depth of approximately 100-150 μm into the cartilage surface. The WST-1 assay demonstrated that APTMS-MBA siloxane was significantly less cytotoxic than nBCA adhesive as an undiluted conditioned supernatant (P < 0.001). These results suggest that the APTMS-MBA siloxane may be a useful adhesive for medical applications.