Narrative review of the choices of stem cell sources and hydrogels for cartilage tissue engineering

Abstract

Stem cell-based therapy is a promising treatment for cartilage defects due to the pluripotency, abundant sources and low immunogenicity of stem cells. Hydrogels are a promising class of biomaterials for cartilage engineering and are characterized by bioactivity, degradability and elasticity as well as provide water content and mechanical support. The combination of stem cells and hydrogels opens new possibilities for cartilage tissue engineering. However, the selection of suitable types of stem cells and hydrogels is difficult.Currently, various types of stem cells, such as embryonic stem cells (ESCs), mesenchymal stem cells (MSCs), induced pluripotent stem cells (iPSCs), and peripheral blood mononuclear cells (PBMSCs), and various types of hydrogels, including natural polymers, chemically modified natural polymers and synthetic polymers, have been explored based on their potential for cartilage tissue engineering. These materials are used independently or in combination; however, there is no clear understanding of their merits and disadvantages with regard to their suitability for cartilage repair. In this article, we aim to review recent progress in the use of stem cell-hydrogel hybrid constructs for cartilage tissue engineering. We focus on the effects of stem cell types and hydrogel types on efficient chondrogenesis from cellular, preclinical and clinical perspectives.We compare and analyze the advantages and disadvantages of these cells and hydrogels with the hope of increasing discussion of their suitability for cartilage repair and present our perspective on their use for the improvement of physical and biological properties for cartilage tissue engineering.

Combinations of Hydrogels and Mesenchymal Stromal Cells (MSCs) for Cartilage Tissue Engineering—A Review of the Literature

“…Current research focuses on the use of these three-dimensional hydrogels, which mimic the extracellular matrix (ECM) of hyaline cartilage to further optimize the treatment of cartilage defects. Both cell-free and cell-laden hydrogels have been used to treat cartilage defects [ 14 , 21 , 22 , 23 , 24 ]. Hydrogels used for the treatment of cartilage defects have to be highly biodegradable and biocompatible, possess strong water binding capacity enabling them to double their size through swelling, and present a certain porosity [ 20 ].…”

“…Hydrogels used for the treatment of cartilage defects have to be highly biodegradable and biocompatible, possess strong water binding capacity enabling them to double their size through swelling, and present a certain porosity [ 20 ]. In addition, injectable hydrogels offer the advantage that they can be shaped to fit into individual-sized and -shaped cartilage defects [ 14 , 25 ]. Hydrogels can be divided into natural, synthetic, or modified natural hydrogels depending on the polymeric material they are built from.…”

“…Therefore, to optimize clinical approaches for cell-based cartilage engineering, a beneficial 3D-microenvironment is necessary, containing a specific combination of biomaterials and growth factors to further enhance chondrogenesis in seeded cells. These biomaterials include hydrogels which are formed from various natural, synthetic, or modified polymers, retain large amounts of water and mimic the natural structure of hyaline cartilage to optimize chondrogenic differentiation and enhance cell functionality in MSCs [ 14 ]. Although the lack of mechanical stability, controlled biodegradability, or immunogenicity pose important challenges, hydrogels have been approved and successfully used in clinical approaches for the engineering of cartilage or intervertebral discs [ 12 , 15 , 16 , 17 ].…”

“…Cell-laden hydrogels can be manufactured according to defect composition, can be applied via minimal-invasive approaches, and may promote the repair of full-thickness cartilage defects [ 18 ]. In addition, the combination of natural and synthetic hydrogels and growth factors has been shown to enhance chondrogenic differentiation, maintain chondrogenic phenotype, and limit chondrogenic hypertrophy in seeded MSCs [ 14 , 15 , 19 ].…”

Skin wound healing promoted by novel curcumin-loaded micelle hydrogel

“…In recent years, research on hydrogels has received increased attention. Hydrogels are widely used in the medical field for drug delivery (6,7), tissue engineering, as sensors (8), and (6,9,10) in antibiotic therapy. With the development of tissue engineering techniques, new drugs have been added to the kit of traditional dressings in order to improve effective treatment (11).…”