Synthesis, characterization, and cytotoxicity of PCL–PEG–PCL diacrylate and agarose interpenetrating network hydrogels for cartilage tissue engineering

Abstract

Hydrogels are suitable biomaterials for cartilage tissue engineering due to the excellent ability to retain water to provide suitable environment for the tissue, however, the insufficient mechanical properties often prevent their wider applications. The objective of this study was to fabricate biocompatible hydrogels with good mechanical performance, high‐water content, and porous microstructure for cartilage regeneration. Photocrosslinked hydrogels are one of the most widely used systems in tissue engineering due to the superior mechanical properties. In this study, block copolymer, poly(ε ‐caprolactone)‐poly(ethylene)‐poly(ε‐caprolactone) diacrylate (PCL–PEG–PCL; PEC), was prepared by ring‐opening polymerization, and PEC hydrogels were made through free radical crosslinking mechanism. Agarose network is chosen as another component of the hydrogels, because of the high‐swelling behavior and cartilage‐like microstructure, which is helpful for chondrocytes growth. Interpenetrating networks (IPN) were fabricated by diffusing PEC into agarose network followed by photo‐crosslinking process. It was noted that incorporating PEC into the agarose network increased the elastic modulus and the compressive failure properties of individual component networks. In addition, high‐swelling ratio and uniform porosity microstructures were found in the IPN hydrogels. IPN and PEC showed low cytotoxicity and good biocompatibility in elution test method. The results suggest promising characteristics of IPN hydrogels as a potential biomaterial for cartilage tissue engineering.

Novel Trends in Hydrogel Development for Biomedical Applications: A Review

“…IPN hydrogels may be preferred over polymer blends due to their improved mechanical strength, controlled swelling behavior and efficient drug loading capacity [ 259 , 261 ]. One of the most used biopolymers for IPN formation is CTS, as reported by Dragan et al (2020) [ 262 ], although there have been a large number of research papers based on IPN hydrogels synthesized with different synthetic and natural polymers, such as COL [ 263 , 264 , 265 ], GEL [ 266 , 267 , 268 ], alginate [ 267 , 269 , 270 ], polyurethane [ 264 , 265 , 270 ], PVA [ 268 , 271 ], PEG [ 272 , 273 ] and poly (aspartic acid) [ 274 ], among other candidate polymers. In this sense, there is a wide range of possibilities by means of materials and synthesis procedures that can be used for IPNs formation, owing to their outstanding physicochemical properties.…”

Strong and tough, pH sensible, interpenetrating network hydrogels based on gelatin and poly(methacrylic acid)

“…A summary of compressive mechanical properties of previously reported hydrogels containing more than 60% of water [ 62–75 ] …”

“…In addition, when PMAA content in hydrogel was lower, there was not enough PMAA to form strong primary network and efficiently hold gelatin, resulting in a weaker and softer structure. As PMAA content increased, the cross-linking was more efficient and gelatin was firmly embedded in F I G U R E 4 A summary of compressive mechanical properties of previously reported hydrogels containing more than 60% of water [62][63][64][65][66][67][68][69][70][71][72][73][74][75] the network of PMAA. The sharp increase in mechanical performances evidenced within the MAA concentration range from 0.2 to 0.4 ml/ml indicates the formation of strong, interconnected primary network of PMAA.…”

Recent Advances in Engineering Bioinks for 3D Bioprinting

“…Additionally, the strong absorption capacity helps maintain cell morphology and pore elastic structure. [ 122 ] Thus, agarose is an ideal sacrificial biomaterial for encapsulating cells. An in‐depth study found that the structure of agarose makes it more stable and harder than that of gelatin.…”