Enhancement of surface adhesion between Poly(L-lactic Acid) and medical-grade 316L stainless steel
SURFACES AND INTERFACES, vol.94, 2026 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 94
- Publication Date: 2026
- Doi Number: 10.1016/j.surfin.2026.109547
- Journal Name: SURFACES AND INTERFACES
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Istanbul Kültür University Affiliated: No
Abstract
Medical-grade stainless steel 316 L (SS316L) is extensively employed in orthopaedic implants owing to its excellent mechanical performance, however, the absence of inherent biological activity requires surface modification to improve its biological compatibility. Bioactive coatings like electrically active polymer poly(L-lactic acid) (PLLA) enhance tissue integration but suffer from poor metal-polymer adhesion. In this study, the relationship between surface thermal and UV treatment methods for preparing stainless steel for a subsequent silanization step, and the resulting adhesion of PLLA coatings on top of medical-grade stainless steel 316 L substrates, has been demonstrated. The work provides mechanistic insights into surface modification strategies, where both thermal and UV treatments were shown to effectively generate hydroxyl groups on top of the SS316L surfaces. A key finding is related to the UV treatment that significantly improves the adhesion between PLLA films and SS316L substrates being 5 B in the cross-hatch tape test. This enhancement is linked with the uniform distribution of the hydroxyl and silane structures and the ability to control the surface's electrocatalytic activity and surface electronic properties with UV irradiation, a feature not observed with thermal treatment. Based on these findings, the superior conditions with UV treatment can be achieved for durable bonding in PLLA/SS316L devices.