Biopolymer films of silk fibroin and chitosan with dendritic surface modification: Structural, mechanical, and...

Multifunctional biomaterials based on natural polymers are promising for biomedical applications. Herein, silk fibroin (SF) and chitosan (Ch) films were prepared by solvent casting and characterized regarding their structural, mechanical, and biofunctional properties. The SF/Ch blend exhibited tuneable features by combining the mechanical strength of SF with the hydrophilicity and bioadhesion of Ch. DMSO acted as a plasticizer, promoting β-sheet formation and flexibility. A key innovation is the selective dendronization of one film surface using a Newkome-type dendron, confirmed by FTIR-ATR and AFM, which enabled asymmetric surface functionalization. As a proof of concept, fluorescein was successfully incorporated into the films, and its homogeneous distribution and retention were evidenced through UV-Vis and confocal microscopy. This result highlights the potential of the developed matrices for drug loading and delivery. Furthermore, the cytocompatibility was confirmed in vitro using fibroblast and keratinocyte cell lines. By merging biocompatibility with functional versatility, this work positions SF/Ch dendronized films at the forefront of innovative strategies for wound healing and drug delivery.