Self-assembling peptide-laden electrospun scaffolds for guided mineralized tissue regeneration

Abstract

Objectives: Electrospun scaffolds are a versatile biomaterial platform to mimic fibrillar structure of native tissues extracellular matrix, and facilitate the incorporation of biomolecules for regenerative therapies. Self-assembling peptide P₁₁-4 has emerged as a promising strategy to induce mineralization; however, P₁₁-4 application has been mostly addressed for early caries lesions repair on dental enamel. Here, to investigate P₁₁-4's efficacy on bone regeneration, polymeric electrospun scaffolds were developed, and then distinct concentrations of P₁₁-4 were physically adsorbed on the scaffolds.

Methods: P₁₁-4-laden and pristine (P₁₁-4-free) electrospun scaffolds were immersed in simulated body fluid and mineral precipitation identified by SEM. Functional groups and crystalline phases were analyzed by FTIR and XRD, respectively. Cytocompatibility, mineralization, and gene expression assays were conducted using stem cells from human exfoliated deciduous teeth. To investigate P₁₁-4-laden scaffolds potential to induce in vivo mineralization, an established rat calvaria critical-size defect model was used.

Results: We successfully synthesized nanofibrous (∼ 500 nm fiber diameter) scaffolds and observed that functionalization with P₁₁-4 did not affect the fibers' diameter. SEM images indicated mineral precipitation, while FTIR and XRD confirmed apatite-like formation and crystallization for P₁₁-4-laden scaffolds. In addition, P₁₁-4-laden scaffolds were cytocompatible, highly stimulated cell-mediated mineral deposition, and upregulated the expression of mineralization-related genes compared to pristine scaffolds. P₁₁-4-laden scaffolds led to enhanced in vivo bone regeneration after 8 weeks compared to pristine PCL.

Significance: Electrospun scaffolds functionalized with P₁₁-4 are a promising strategy for inducing mineralized tissues regeneration in the craniomaxillofacial complex.

Keywords: Biomineralization; Bone regeneration; Electrospinning; Scaffolds, Self-assembling peptide.