Evaluation of Colombian silk fibroin hydrogels functionalized with recombinant LSECtin for intervertebral disc tissue engineering

Abstract

This study evaluated the potential of Colombian silk fibroin hydrogels functionalized with recombinant LSECtin (rLSECtin) for intervertebral disc tissue engineering. In silico analysis indicated that rLSECtin may interact with glycans similar to those found in human adipose-derived stem cells (ADSCs) through residues Asn105, Asp106, Glu93, Asn87, and Glu85, which coordinate calcium to form hydrogen bonds with GlcNAc hydroxyl groups. rLSECtin was successfully produced, purified, and incorporated into silk fibroin hydrogels. Thermal analysis showed that the hydrogels were resistant to sterilization, and rheological studies demonstrated predominantly elastic, gel-like behavior. The secondary structure of the hydrogels was largely determined by α-helical content, which is related to silk I with β-sheets also contributing as a result of sonication-induced structuring. Metabolic activity assays indicated that rLSECtin was associated with increased ADSC metabolic activity under two-dimensional conditions, whereas hydrogels containing rLSECtin maintained cell viability, as confirmed by cell viability assays. Differentiated constructs exhibited glycosaminoglycan-rich extracellular matrix and chondrocyte-like morphology, whereas rLSECtin-functionalized hydrogels showed increased transcription of SOX9 , ACAN , and COL2A1 , along with elevated COL10A1 of uncertain significance for nucleus pulposus stability. Overall, Colombian silk fibroin hydrogels provide a mechanically stable and cytocompatible platform relevant for nucleus pulposus tissue engineering, in which rLSECtin appears to act primarily as a biochemical modulator rather than a structural modifier. These findings support a proof of concept for lectin-functionalized biomaterials in intervertebral disc regeneration. However, further studies, including mechanistic validation of glycan–lectin interactions, protein-level confirmation, quantitative extracellular matrix analysis, and evaluation of signaling pathways, are required to establish functional and translational relevance.