Chondro-inductive hyaluronic acid/chitosan coacervate-based scaffolds for cartilage tissue engineering.

Injuries related to articular cartilage are among the most challenging musculoskeletal problems because of poor repair capacity of this tissue. The lack of efficient treatments for chondral defects has stimulated research on cartilage tissue engineering applications combining porous biocompatible scaffolds with stem cells in the presence of external stimuli. This work presents the role of rat bone marrow mesenchymal stem cell (BMSC) encapsulated-novel three-dimensional (3D) coacervate scaffolds prepared through complex coacervation between different chitosan salts (CHI) and sodium hyaluronate (HA). The 3D architecture of BMSC encapsulated scaffolds (HA/CHI) was shown by scanning electron microscopy (SEM) to have an interconnected structure to allow cell-cell and cell-matrix interactions. Chondrogenic induction of encapsulated BMSCs within HA/CHI coacervates demonstrated remarkable cellular viability in addition to the elevated expression levels of chondrogenic markers such as sex determining region Y-box 9 protein (SOX9), aggrecan (ACAN), cartilage oligomeric matrix protein (COMP) and collagen type II (COL2A1) by immunofluorescence staining, qPCR and ELISA test. Collectively, HA/CHI coacervates are promising candidates for future use of these scaffolds in cartilage tissue engineering applications. [Display omitted] • Rat BMSCs were encapsulated in HA/CHI coacervates and those cells had a viability over > 84 %. • After chondrogenic induction, coacervate encapsulated BMSCs were observed as well-distributed and in a round shape. • Upregulation of COL2A1 and ACAN genes were shown both in qPCR and ELISA. • Chondrogenic proteins were detected mostly in pericellular area while BMSCs appeared as a lacunae-embedded chondrocyte. • Chondrogenic markers of coacervate encapsulated BMSCs increased with or without induction. [ABSTRACT FROM AUTHOR]