Preparation of Assemblable Chondral and Subchondral Bone Microtissues for Osteochondral Tissue Engineering

Abstract

Microtissues exhibit great advantages in injecting with minimum invasiveness, mimicking natural tissues, and promoting tissue regeneration. However, very few studies have focused on the construction of osteochondral microtissues that could simultaneously support hyaline-like cartilage and bone tissue regeneration. In this study, chondral microtissues that could favor the formation of hyaline-like cartilages and subchondral bone microtissues that could repair subchondral defects to support the neo-generated cartilages were successfully constructed for osteochondral tissue engineering. For chondral repair, the developed chondral microgels with high porosity and hydrophilicity could make cells spherical, favor the formation of cell aggregates, and show an excellent differentiation effect toward hyaline-like cartilage, thus contributing to the production of chondral microtissues. For subchondral bone repair, the fabricated subchondral microgels realize cell adhesion and proliferation and support the osteogenic differentiation of stem cells, thus favoring the formation of subchondral bone microtissues. The injectable chondral and subchondral bone microtissues could be stably assembled by Michael addition reaction between sulfhydryl groups of microtissues and double bonds of hydrophilic macromolecular cross-linker. At 12 weeks postimplantation, osteochondral microtissues could support the reconstruction of osteochondral-like tissues. The present study provides new insight into the microtissues for repair of osteochondral tissues.

Injectable and Degradable POSS–Polyphosphate–Polysaccharide Hybrid Hydrogel Scaffold for Cartilage Regeneration

“…In addition, the histological evaluation via HE and SF staining , was performed to assess the cartilage regeneration. As shown in Figure d,e, the articular cartilage in the sham group exhibited a smooth surface, standard structural organization, normal cellularity, and vigorous intensity of SF staining.…”

“…Consistently, referring to the International Cartilage Repair Score (ICRS) standard, while the total score is 12, the POSS-PEEP/HA/TGF-β 3 /hMSCs group showed higher ICRS macroscopic scores (11.00 ± 0.58) than the PBS group (4.00 ± 1.00) and the POSS-PEEP/HA/hMSCs group (7.50 ± 1.71, Figure 7b). In addition, the histological evaluation via HE and SF staining 54,55 was performed to assess the cartilage regeneration.…”

Smart Responsive Organic Emitters: Intrinsic Mechanisms and Versatile Applications

“…Molecular motion in aggregate states [ 86–90 ] under external stimuli has been an attractive topic in recent years, which usually arouses tunable emission behaviors because of molecular packing variations and the modulated intermolecular interactions. As shown in Figure , typical examples of molecular motion include photoinduced molecular motion and acid‐induced molecular motion.…”

Injectable cartilage microtissues based on 3D culture using porous gelatin microcarriers for cartilage defect treatment

“…However, the implantation of bulk scaffolds or engineered tissues often requires invasive surgical operations, which may cause secondary damage and increase the risk of inflammation, among other side effects [ 13 , 14 ]. In contrast, the microtissue strategy shows great application prospects in an injectable manner with minimal invasiveness, fitting defects with complex shapes and efficiently promoting tissue regeneration [ 15–17 ]. Simultaneously, microtissues can be precisely designed and manufactured to achieve a biomimetic cell density and microenvironment, establish effective substance exchange and cell connections and facilitate extracellular matrix deposition [ 18–21 ].…”