Review of Synthetic and Hybrid Scaffolds in Cartilage Tissue Engineering

Abstract

Cartilage tissue is under extensive investigation in tissue engineering and regenerative medicine studies because of its limited regenerative potential. Currently, many scaffolds are undergoing scientific and clinical research. A key for appropriate scaffolding is the assurance of a temporary cellular environment that allows the cells to function as in native tissue. These scaffolds should meet the relevant requirements, including appropriate architecture and physicochemical and biological properties. This is necessary for proper cell growth, which is associated with the adequate regeneration of cartilage. This paper presents a review of the development of scaffolds from synthetic polymers and hybrid materials employed for the engineering of cartilage tissue and regenerative medicine. Initially, general information on articular cartilage and an overview of the clinical strategies for the treatment of cartilage defects are presented. Then, the requirements for scaffolds in regenerative medicine, materials intended for membranes, and methods for obtaining them are briefly described. We also describe the hybrid materials that combine the advantages of both synthetic and natural polymers, which provide better properties for the scaffold. The last part of the article is focused on scaffolds in cartilage tissue engineering that have been confirmed by undergoing preclinical and clinical tests.

Host Response to Biomaterials for Cartilage Tissue Engineering: Key to Remodeling

“…Natural polymers include polysaccharides (such as HA, alginate, and chitosan) and proteins (gelatin, silk fibroin, and fibrin), are widely used in the production of scaffolds for cartilage regeneration. Due to their origins, These materials are characterized by high biocompatibility, bioactivity, and the degradation products are non-toxic; but, their low mechanical stability, rapid degradation, and poor stability greatly limits their applications ( Wasyłeczko et al, 2020 ). For example, alginate based hydrogel scaffolds can support the growth and proliferation of enveloped chondrocytes and maintain their chondrocyte morphology, but they have poor stability and loss of mechanical strength in a short period of time ( Bao et al, 2020 ).…”

Tuning the Properties of PNIPAm-Based Hydrogel Scaffolds for Cartilage Tissue Engineering

“…It is crucial to understand the complex structure of the articular cartilage (AC) before developing a mimicking construct to repair damaged tissue. Articular cartilage is an elastic tissue that consists of spheroid chondrocyte cells (2% of the total volume of the AC) protected by the surrounding ECM [ 23 ]. The solid phase of the AC is porous and permeable, while the main part of the fluid phase is water containing inorganic ions such as sodium, potassium, and chloride [ 24 ].…”

“…The solid phase of the AC is porous and permeable, while the main part of the fluid phase is water containing inorganic ions such as sodium, potassium, and chloride [ 24 ]. The ECM, which provides support and protection for the chondrocytes, is mainly composed of water, collagens (type II), proteoglycans, and non-collagenous glycoproteins [ 23 , 24 ]. The main function of the AC is to transmit loads to the related subchondral bone and absorb impact forces, resulting in low-friction gliding between the surfaces of the joints [ 24 ].…”

Bioengineered extracellular vesicle-loaded bioscaffolds for therapeutic applications in regenerative medicine

“…EVs as a special biological component provide more possibilities to functionalize scaffold materials with biological functions. By integrating biochemistry and bioengineering principles, EV bioscaffold products have shown promising therapeutic outcomes in numerous medical studies, such as wound healing, tissue regeneration, vascularization, and angiogenesis [Figure 1] [8,13,17] . In addition, appropriate EV delivery systems have shown obvious advantages for further enhancing the function of EV modified bioscaffolds [15,18] .…”

“…By integrating biochemistry and bioengineering principles, EV bioscaffold products have shown promising therapeutic outcomes in numerous medical studies, such as wound healing, tissue regeneration, vascularization, and angiogenesis [ Figure 1 ] [ 8 , 13 , 17 ] . In addition, appropriate EV delivery systems have shown obvious advantages for further enhancing the function of EV modified bioscaffolds [ 15 , 18 ] . Therefore, future research may focus on further refinement of EV modified scaffolds, such as the loading and release mechanisms, the loading density and release profile, storage stability, and safety must be fully characterized before clinical applications.…”