Rapid fabrication of gelatin-based scaffolds with prevascularized channels for organ regeneration

Abstract

One of the biggest hindrances in tissue engineering in recent decades has been the complexity of the prevascularized channels of the engineered scaffold, which was still lower than that of human tissues. Another relative difficulty was the lack of precision molding capability, which restricted the clinical applications of the huge engineered scaffold. In this study, a promising approach was proposed to prepare hydrogel scaffold with prevascularized channels by liquid bath printing, in which chitosan/β-sodium glycerophosphate served as the ink hydrogel, and gelation/nanoscale bacterial cellulose acted as the supporting hydrogel. Here, the ink hydrogel was printed by a versatile nozzle and embedded in the supporting hydrogel. The ink hydrogel transformed into liquid effluent at low temperature after the cross-linking of gelatin by microbial transglutaminase (mTG). No residual template was seen on the channel surface after template removal. This preparation had a high degree of freedom in the geometry of the channel, which was demonstrated by making various prevascularized channels including circular, branched, and tree-shaped networks. The molding accuracy of the channel was assessed by studying the roundness of the cross section of the molded hollow channel, and the effect of the mechanical properties by adding bacterial cellulose to the supporting hydrogel was analyzed. Human umbilical vein endothelial cells were injected into the aforementioned channels which formed a confluent and homogeneous distribution on the surface of the channels. Altogether, these results showed that this approach can construct hydrogel scaffolds with complex and accurate molding prevascularized channels, and hs great potential to resolve the urgent vascularization issue of bulk tissue-engineering scaffold.

Recent Advances on Cell-Based Co-Culture Strategies for Prevascularization in Tissue Engineering

“…An aligned microchannels network can be fabricated using this technique that will be used for the adhesion of endothelial cells to form an intricate and aligned endothelial network ( Jiang and Luo, 2013 ). Another method of developing a microchannel network is using a biodegradable sacrificial template that can be degraded or washed after implantation and forming the microchannel network ( Miller et al, 2012 ; Li et al, 2017 ; Hu et al, 2021 ). The microchannels can also be formed using laser biodegradation techniques ( Pradhan et al, 2017 ).…”

Vascularization in tissue engineering: The architecture cues of pores in scaffolds

“…76 Scaffolds with hollow channel structures based on bioceramics, hydrophobic polymer, and hydrogels have been fabricated by various techniques for vascularized tissue engineering application. [77][78][79] For example, β-TCP scaffolds containing macropore and hollow channels were prepared by paraffin temperate for bone tissue engineering. After implantation in vivo for 4 weeks, significantly more blood vessels were formed in the middle layer of the channeled scaffolds than the scaffolds without channels, implying that channel structure could promote vertical growth of host vasculature from bone to scaffolds.…”

Concentration Selection of Biofriendly Enzyme-Modified Gelatin Hydrogels for Periodontal Bone Regeneration

“…Biocompatibility is the basis of tissue regeneration. Previous studies have proven the biocompatibility 57,58 of TG-Gel hydrogels and seeded human umbilical vein endothelial cells, 59 human adipose-derived stem cells, 60,61 human fibroblast cells, 62 human myoblasts cells 29 as well as mouse mesenchymal stromal cells 25 onto such similar materials or tried to encapsulate cells in the hydrogels. 58 Similarly, our results showed that hPDLSCs could successfully attach to hydrogel surfaces and realize infiltrative growth into the hydrogels.…”