Engineering cartilage or endochondral bone: A comparison of different naturally derived hydrogels

Abstract

Cartilaginous tissues engineered using mesenchymal stem cells (MSCs) have been shown to generate bone in vivo by executing an endochondral program. This may hinder the use of MSCs for articular cartilage regeneration, but opens the possibility of using engineered cartilaginous tissues for large bone defect repair. Hydrogels may be an attractive tool in the scaling-up of such tissue engineered grafts for endochondral bone regeneration. In this study, we compared the capacity of different naturally derived hydrogels (alginate, chitosan, and fibrin) to support chondrogenesis and hypertrophy of MSCs in vitro and endochondral ossification in vivo. In vitro, alginate and chitosan constructs accumulated the highest levels of sGAG, with chitosan constructs synthesising the highest levels of collagen. Alginate and fibrin constructs supported the greatest degree of calcium accumulation, though only fibrin constructs calcified homogenously. In vivo, chitosan constructs facilitated neither vascularization nor endochondral ossification, and also retained the greatest amount of sGAG, suggesting it to be a more suitable material for the engineering of articular cartilage.Both alginate and fibrin constructs facilitated vascularization and endochondral bone formation as well as the development of a bone marrow environment. Alginate constructs accumulated significantly more mineral and supported greater bone formation in central regions of the engineered tissue. In conclusion, this study demonstrates the capacity of chitosan hydrogels to promote and better maintain a chondrogenic phenotype in MSCs and highlights the potential of utilizing alginate hydrogels for MSC-based endochondral bone tissue engineering applications.

3D Bioprinting of Developmentally Inspired Templates for Whole Bone Organ Engineering

“…It is well established that alginate hydrogels can support robust chondrogenesis [20,21] , with the incorporation of RGD peptides having previously been shown to lead to enhanced osteogenesis when this biomaterial is used for bone tissue engineering applications [15,17] . Furthermore, we chose to use a gamma-irradiated alginate as the relatively slow degradation rate of this hydrogel in its non-modified form has previously been shown to impede endochondral bone regeneration [22] .…”

Hybrid extracellular matrix design for cartilage‐mediated bone regeneration

“…After 20 days, 65% weight remained in the 100% HA but only 1% weight remained in the 100% FB. The degradation for combination hydrogels were as follows: 1, 1, 3, 11, 25, 33, 42, 50, and 50% of the weight remained for 10,20,30,40,50,60,70,80, and 90% HA, respectively. Degradation study did not include cells, and therefore no enzymatic degradation occurred.…”

“…Their results showed that fibrin had the least sGAG formation compared to the other groups. 50 As HA was added to the constructs, very little to no evidence of sGAG formation was observed at the lower ranges of HA. This could be contributed by the higher levels of FB.…”

Biomaterials for Cartilage Tissue Engineering

“…For example in the case of bone marrow mesenchymal stem cells (BMSCs) encapsulated in fibrin the results confirm a diminished chondrogenic potential [37]. At the moment, this subject is still studied.…”