Engineering of Hydrogel Materials with Perfusable Microchannels for Building Vascularized Tissues

Abstract

Vascular systems are responsible for various physiological and pathological processes related to all organs in vivo, and the survival of engineered tissues for enough nutrient supply in vitro. Thus, biomimetic vascularization is highly needed for constructing both a biomimetic organ model and a reliable engineered tissue. However, many challenges remain in constructing vascularized tissues, requiring the combination of suitable biomaterials and engineering techniques. In this review, the advantages of hydrogels on building engineered vascularized tissues are discussed and recent engineering techniques for building perfusable microchannels in hydrogels are summarized, including micromolding, 3D printing, and microfluidic spinning. Furthermore, the applications of these perfusable hydrogels in manufacturing organ‐on‐a‐chip devices and transplantable engineered tissues are highlighted. Finally, current challenges in recapitulating the complexity of native vascular systems are discussed and future development of vascularized tissues is prospected.

Application of bioactive hydrogels combined with dental pulp stem cells for the repair of large gap peripheral nerve injuries

“…Nowadays, hydrogels derived from natural biomaterials, for example, the polysaccharide-based materials (such as cellulose, chitosan, etc) or the protein-based materials (such as collagen, gelatin, etc. ), have been widely used in tissue engineering [ 20 , 21 ], because of their good biocompatibility and biodegradability, extensive availability and excellent biological properties [ 20 ]. Whereas, polysaccharide-based natural materials such as chitosan has poor solubility under physiological conditions, which is the key limiting factor for its application in tissue engineering [ 22 , 23 ].…”

Transcribing In Vivo Blood Vessel Networks into In Vitro Perfusable Microfluidic Devices

“…Many applications may not require the precise resolution of the laser ablation‐based methods, or the cellular complexity of the 3D printing methods. Our channel resolution ranges from 500 µm to 1 cm, which is similar to other 3D printing techniques [ 21 ] and is done with off‐the‐shelf 3D printers and inexpensive PLA filament. The use of an expensive high‐resolution 3D printer could improve the resolution of the 3D printed models, and their final PDMS device channels.…”

“…[ 11–20 ] A review of vascular manufacturing technologies by Xie et al summarizes these technologies. [ 21 ] These methods have advantages, but require the use of customized and expensive equipment or materials, including customized laser‐ablation microscopes, clean rooms, custom 3D printers, and unique hydrogels or bioinks. For example, laser‐ablation has been used to create detailed replicates of the blood vessel networks seen in vivo, [ 18,19 ] but requires expensive two‐photon microscopes, custom stage controllers, and/or custom software.…”

Microfluidic Skin‐on‐a‐Chip Models: Toward Biomimetic Artificial Skin

“…In addition to 3D printing, hydrogel‐based techniques, including micromolding and microfluidic spinning can be employed to fabricate vascular channels. [ 105 ]…”

“…In addition to 3D printing, hydrogel-based techniques, including micromolding and microfluidic spinning can be employed to fabricate vascular channels. [105] The fabrication of a vascularized skin equivalent has the potential to enhance our understanding of paracrine signaling within the skin and improve the relevance of current skin models. Blood vessels modeled in microfluidic skin equivalents are not yet at the dimensions relevant to capillaries as seen in alternate skin models fabricated angiogenically.…”