Prevention of brain scarring during cranial reconstruction through a bioactive polymer coating

Although cranioplasty is a long-established surgical procedure used to repair or reshape skull defects, it is not devoid of side effects arising from the formation of a scar tissue between dura, implant, and subcutaneous tissue. To minimize these complications, we developed a bioactive coating comprising poly(vinyl alcohol) (PVA) electrospun fibers loaded with a polyanhydride based on betulin disuccinate and a tricarboxylic derivative of poly(ethylene glycol) (PEG-DBB), suitable for the modification of the surface of titanium alloys. Although cell viability assays proved biocompatibility of fibers, PVA/PEG-DBB was found to decrease the adhesion of neuroblastoma cells by 84 % and the adhesion of fibroblast cells by 11 %, while increasing the confluency of osteosarcoma cells by 40 %. To assess the potential of the PVA/PEG-DBB fibrous coating, it was deposited onto the surface of Ti-6Al-4V alloy discs via electrospinning. In vitro bioactivity of samples was assessed via immersion in a simulated body fluid for 21 days, revealing facilitated formation of hydroxyapatite layer (Ca/P ratio of 1.74) in the presence of PVA/PEG-DBB (54.0 ± 6.5 % surface coverage, 11.7 ± 1.3 μm thickness), as confirmed by scanning electron microscopy and Raman spectroscopy. Adhesion strength of the coating to the substrate (between 1.7 and 2.7 N) was quantified using scratch testing under progressive loading, with critical load values determined to evaluate interfacial bonding integrity. By integrating biocompatibility, modulated adhesiveness, and mechanical resilience, PVA/PEG-DBB coating presents a promising approach for enhancing cranioplasty outcomes and minimizing adhesion-related complications.