Chondroitin Sulfate- and Decorin-Based Self-Assembling Scaffolds for Cartilage Tissue Engineering

Abstract

Cartilage injury and degenerative tissue progression remain poorly understood by the medical community. Therefore, various tissue engineering strategies aim to recover areas of damaged cartilage by using non-traditional approaches. To this end, the use of biomimetic scaffolds for recreating the complex in vivo cartilage microenvironment has become of increasing interest in the field. In the present study, we report the development of two novel biomaterials for cartilage tissue engineering (CTE) with bioactive motifs, aiming to emulate the native cartilage extracellular matrix (ECM). We employed a simple mixture of the self-assembling peptide RAD16-I with either Chondroitin Sulfate (CS) or Decorin molecules, taking advantage of the versatility of RAD16-I. After evaluating the structural stability of the bi-component scaffolds at a physiological pH, we characterized these materials using two different in vitro assessments: re-differentiation of human articular chondrocytes (AC) and induction of human adipose derived stem cells (ADSC) to a chondrogenic commitment. Interestingly, differences in cellular morphology and viability were observed between cell types and culture conditions (control and chondrogenic). In addition, both cell types underwent a chondrogenic commitment under inductive media conditions, and this did not occur under control conditions. Remarkably, the synthesis of important ECM constituents of mature cartilage, such as type II collagen and proteoglycans, was confirmed by gene and protein expression analyses and toluidine blue staining. Furthermore, the viscoelastic behavior of ADSC constructs after 4 weeks of culture was more similar to that of native articular cartilage than to that of AC constructs. Altogether, this comparative study between two cell types demonstrates the versatility of our novel biomaterials and suggests a potential 3D culture system suitable for promoting chondrogenic differentiation.

Cartilage Tissue Engineering Using Self-Assembling Peptides Composite Scaffolds

“…Constructs cultured under expansion medium showed less staining, while constructs under control medium became weakly stained. [42].…”

“…Significant differences are indicated as * for p < 0.05, ** for p < 0.01, and *** for p < 0.001, one-way ANOVA, N = 2 n = 3). Adapted from Recha-Sancho and Semino [42].…”

Development of a Three-Dimensional Bioengineered Platform for Articular Cartilage Regeneration

“…Scaffold morphological characterization showed a cell-cell-interaction-enabling role of RAD16-I self-assembling peptide nanostructure within PCL scaffolds. These peptide networks, allow a better cellular distribution among the construct, creating a denser structure, which can promote cellular signaling, and improved chondrogenic differentiation in presence of pro-chondrogenic factors, as has been previously shown [20,33,37,38]. Micron-sized fibers and a uniformly porous scaffold allows the cells to sense the matrix as a three-dimensional microenvironment [48,49].…”

“…In RAD16-I cell encapsulations, the final construct size was reduced to around 2.2 mm compared to the 6 mm initial size (Figure 3k,l). As previously described, chondrogenic medium promotes cell differentiation, which led to a higher degree of self-assembling polymer contraction by its degradation from cells, cell-cell extensive network formation and cell contraction processes producing also a global contraction [20,32,38]. Unlike RAD16-I samples cultured with expansion medium, higher magnification images of chondrogenic RAD16-I samples showed the presence of cells surrounded by a non-oriented, non-fiber-shaped substance, which corresponds to deposited ECM (Figure 3k,l).…”

Aerogels made of chitosan and chondroitin sulfate at high degree of neutralization: Biological properties toward wound healing

“…3,4 Moreover, CS can be molded in different forms, such as films, gels, sponges, fibers, nanoparticles, nanofibers; and combined with glycosaminoglycans (GAGs), such as chondroitin sulfate (ChS), can form sponges and scaffolds for diverse applications in tissue engineering. [5][6][7] ChS is an anionic polymer found as a natural GAG in the extracellular matrix (ECM) 8,9 typically of cartilage, skin, cornea, and the umbilical cord, and it is used in medicine for cartilage tissue engineering, in anti-inflammatory and antimicrobial devices, 10,11 and as a vehicle in pharmacological systems. 12 Furthermore, it shows activity in cell differentiation and proliferation.…”