In this paper, a novel bioinspired stem cell‐laden microgel and related in vivo cartilage repair strategy are proposed. In particular, herein the preparation of new stem cell‐laden microgels, which can be injected into the chondral defect site in a minimally invasive way, and more importantly, capable of in situ self‐assembly into 3D macroporous scaffold without external stimuli, is presented. Specifically, thiolated gelatin (Gel‐SH) and vinyl sulfonated hyaluronic acid (HA‐VS) are first synthesized, and then stem cell‐laden gelatin/hyaluronic acid hybrid microgels (Gel‐HA) are generated by mixing Gel‐SH, HA‐VS, and bone mesenchymal stem cells (BMSCs) together via droplet‐based microfluidic approach, followed by gelation through fast and efficient thiol‐Michael addition reaction. The encapsulated BMSCs show high viability, proliferation, and chondrogenic differentiation potential in the microgels. Moreover, the in vitro test proves that BMSC‐laden Gel‐HA microgels are injectable without sacrificing BMSC viability, and more importantly, can self‐assemble into cartilage‐like scaffolds via cell–cell interconnectivity. In vivo experiments further confirm that the self‐assembled microgels can inhibit vascularization and hypertrophy. The Gel‐HA microgels and relevant cartilage repair strategy, i.e., injecting BMSC‐laden microgels separately and reconstructing chondral defect structure by microgel self‐assembly, provides a simple and effective method for cartilage tissue engineering and regenerative medicine.
The storage of living cells is the major challenge for cell research and cell treatment. Here, we introduced a novel supramolecular gel cryopreservation system which was prepared in the microchannel, and the supramolecular gel (BDTC) was self-assembled by gelator Boc- O-dodecyl-l-tyrosine (BDT). This cryopreservation system could obviously minimize the cell injury because the BDTC supramolecular gel had a more compact three-dimensional network structure when the BDT gelator self-assembled in the confined space of microchannel. This compact structure could confine the growth of the ice crystal, reduce the change rate of cell volumes and osmotic shock, decrease the freezing point of the cryopreservation system, and possess better protection capability. Furthermore, the results of functionality assessments showed that the thawed cells could grow and proliferate well and remain the same growth trend of the fresh cells after the RSC96 cells flowed out from the microchannel. This novel method has potential to be used for the cryopreservation of cells, cell therapy, and tissue engineering.
Simulating
the structure and function of blood capillaries is very
important for an in-depth insight into their role in the human body
and treatment of capillary-related diseases. Due to the similar composition
and structure, hollow hydrogel microfibers are well-recognized as
potential biomimetic blood capillaries. In this paper, we report a
novel, facile, and reproducible method to fabricate coaxial microfluidic
chips via 3D printing-assisted soft lithography and then hollow hydrogel
microfibers using the as-prepared coaxial microfluidic chips. Instead
of traditional photoresist-based lithography, 3D printing of gelatin
hydrogel under various extrusion pressures is used to construct sacrificial
templates of coaxial microfluidic chips. Various solid and hollow
hydrogel microfibers with complicated and hierarchical structures
can be obtained via multitype coaxial microfluidic chips or a combination
of coaxial microfluidic fabrication and post-treatment. The as-formed
hollow hydrogel microfibers are evaluated in detail as biomimetic
blood capillaries, including physicochemical and cytological properties.
Our results prove that the hollow hydrogel microfibers exhibit excellent
mass transport capacity, hemocompatibility, semipermeability, and
mechanical strength, and their barrier function can be further enhanced
in the presence of endothelial cells. Overall, our 3D printing-assisted
fabrication strategy provides a new technique to construct microfluidic
chips with complicated 3D microchannels, and the resulting hollow
hydrogel microfibers are promising candidates for blood capillaries.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.