Multifunctional 3D printing of heterogeneous hydrogel structures

Abstract

Multimaterial additive manufacturing or three-dimensional (3D) printing of hydrogel structures provides the opportunity to engineer geometrically dependent functionalities. However, current fabrication methods are mostly limited to one type of material or only provide one type of functionality. In this paper, we report a novel method of multimaterial deposition of hydrogel structures based on an aspiration-on-demand protocol, in which the constitutive multimaterial segments of extruded filaments were first assembled in liquid state by sequential aspiration of inks into a glass capillary, followed by in situ gel formation. We printed different patterned objects with varying chemical, electrical, mechanical, and biological properties by tuning process and material related parameters, to demonstrate the abilities of this method in producing heterogeneous and multi-functional hydrogel structures. Our results show the potential of proposed method in producing heterogeneous objects with spatially controlled functionalities while preserving structural integrity at the switching interface between different segments. We anticipate that this method would introduce new opportunities in multimaterial additive manufacturing of hydrogels for diverse applications such as biosensors, flexible electronics, tissue engineering and organ printing.

Development of Bioink from Decellularized Tendon Extracellular Matrix for 3D Bioprinting

“…To evaluate the stiffness of the hydrogels under compressive loading, unconfined compression tests were performed by in‐house developed hardware . the samples with two different concentrations (5 and 10 mg mL −1 ) and different digestion times (48, 60, and 72 h) were tested accordingly.…”

“…More details about the hardware and 3D bioprinting method can be found in refs. . The printed structures were submerged into growth media and incubated at 37 °C with 5% CO 2 concentration.…”

Stretchable current collectors based on carbon embedded in a poly (acrylamide)/poly (N,N-methylenebisacrylamide) hydrogel modified with Nafion 117®

“…These techniques allow to control an extent of homogeneity and to optimize it with respect to the composition of carbon-embedded hydrogels [16]. Yet, poor dispersion of carbons in aqueous solution and within hydrogels is related to their hydrophobic nature [17]. One of the most common methods for improving homogeneity of carbon suspension (in both liquids and hydrogels) is to apply surfactants or other additives [18,19].…”

Hydrogel‐Immobilized Coacervate Droplets as Modular Microreactor Assemblies

“…For example, supramolecular nested microbeads were developed as building blocks to construct macroscopic self‐healing scaffolds, and enzyme‐containing hybrid microcapsules hierarchically organized in agarose hydrogels to facilitate recycling of an immobilized biocatalyst . As individual hydrogels can be shaped and assembled into higher‐order arrangements by 3D printing and controlled crosslinking, they provide a potential pathway to the fabrication of soft modular materials based on the integration of functionally encoded hydrogel building blocks . Such procedures have been primarily exploited for the printing of cell‐laden hydrogels from components such as hyaluronic acid and silk fibroin…”