Silk films with nanotopography and extracellular proteins enhance corneal epithelial wound healing

Abstract

Corneal wound healing depends on extracellular matrix (ECM) and topographical cues that modulate migration and proliferation of regenerating cells. In our study, silk films with either flat or nanotopography patterned parallel ridge widths of 2000, 1000, 800 nm surfaces were combined with ECMs which include collagen type I (collagen I), fibronectin, laminin, and Poly-d-Lysine to accelerate corneal wound healing. Silk films with 800 nm ridge width provided better cell spreading and wound recovery than other size topographies. Coating 800 nm patterned silk films with collagen I proves to optimally further increased mouse and rabbit corneal epithelial cells growth and wound recovery. This enhanced cellular response correlated with redistribution and increase in size and total amount of focal adhesion. Transcriptomics and signaling pathway analysis suggested that silk topography regulates cell behaviors via actin nucleation ARP-WASP complex pathway, which regulate filopodia formation. This mechanism was further explored and inhibition of Cdc42, a key protein in this pathway, delayed wound healing and decreased the length, density, and alignment of filopodia. Inhibition of Cdc42 in vivo resulted in delayed re-epithelization of injured corneas. We conclude that silk film nanotopography in combination with collagen I constitutes a better substrate for corneal wound repair than either nanotopography or ECM alone.

Development of Biomimetic Hepatic Lobule-Like Constructs on Silk-Collagen Composite Scaffolds for Liver Tissue Engineering

“…Recently, increasing evidence pinpoints the importance of matching the performance of biological scaffolds with the in vivo parameters of the microenvironment for engineering structural and functionally equivalent hepatic tissue constructs in vitro ( Luo et al, 2021 ; Stoppato et al, 2015 ). Physical properties, such as porosity, water uptake ability, and mechanical properties, are important features of SF porous scaffolds that modulate the biological behavior of cells toward the desired engineered tissue ( Kundu et al, 2013 ), especially the liver, due to its intricate architecture and specific functionality.…”

Recent Advances in Natural Materials for Corneal Tissue Engineering

“…Silk fibroin, a natural protein extracted from Bombyx mori cocoons, can be formed into films and scaffolds with tunable degradation and mechanical strength with non-immunogenic responses in vivo [ 38 , 80 , 81 ]. Use of silk fibroin as a film or scaffolds for corneal tissue replacement [ 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 , 99 , 100 ] remains an active area of research, as outlined in Table 3 . Silk films and membranes can be fabricated through simple evaporation or electrospinning.…”

“…Researchers commonly use human corneal epithelial cells for biomaterial experimentation [ 30 , 51 , 89 , 90 , 102 , 103 ]. These cells can either be from an immortalized cell line, or freshly isolated from donor epithelium.…”

“…They hypothesize that actin re-organization continues to mediate downstream signaling over time, while the expression of integrin β-1 may be decreased after initial cell attachment. Another group created nanopatterned silk films with coatings of either collagen I, fibronectin, laminin, or poly-D-lysine coatings [ 89 ]. Adherence of primary mouse and rabbit CEpC number increased as the ridge width decreased on noncoated nanopatterned silk films.…”

Multifunctional Baicalin-Modified Contact Lens for Preventing Infection, Regulating the Ocular Surface Microenvironment and Promoting Corneal Repair

“…Ocular surface diseases caused by corneal injury afflict more than 23 million people worldwide ( Stern et al, 2018 ), and are among the most common eye diseases worldwide. Generally, corneal tissue can self-healing through epithelial cell migration and proliferation when the injury is not severe ( Luo et al, 2021 ). However, when the ocular surface has intense inflammation or oxidative stress caused by extensive epithelial damage, dry eye disease, diabetic keratopathy, etc., the self-healing of the corneal epithelial becomes difficult ( Ziaei et al, 2018 ).…”