Bioinspired gallol-modified chitosan coating for improved tissue adhesion and in vivo catheter fixation

Catheter displacement and inadequate fixation remain significant challenges in implantable medical devices, often leading to device migration, repeated interventions, and reduced therapeutic effectiveness. Although various securement methods, such as suturing, mechanical anchoring, and adhesive dressings, have been developed, maintaining adequate fixation durability under wet physiological conditions remains a challenge. This study develops a bioinspired adhesive coating using gallol-modified chitosan (CHI-G) on catheter surfaces for catheter fixation. Two types of CHI-G-coated catheters with low (3-5 μm, CHI-G_L) and high (7-9 μm, CHI-G_H) coating thicknesses were prepared by repeated dehydration cycles of CHI-G. CHI-G-coated catheter surfaces demonstrated enhanced hydrophilicity with a decrease in water contact angles (84.9 ± 2.8 ° for the uncoated control, 74.4 ± 5.2 ° for CHI-G_L, and 66.3 ± 1.9 ° for CHI-G_H). In addition, CHI-G-coated catheter surfaces exhibited excellent adhesion forces (33.1 ± 9.3 kPa for CHI-G_H and 10.6 ± 5.7 kPa for CHI-G_L, respectively) compared to that of unmodified surfaces (2.2 ± 0.8 kPa). In animal experiments, the CHI-G coating on catheter surfaces significantly improved fixation durability. No systemic toxicity of the CHI-G-coated catheter was detected in histological analysis, hematological and biochemical assessments, or rabbit skin irritation tests. Thus, the CHI-G adhesive coating represents an effective bioinspired surface-modification approach for the fixation of implantable materials and catheters.