3‐Dimensional Printing of Hydrogel‐Based Nanocomposites: A Comprehensive Review on the Technology Description, Properties, and Applications

Abstract

Hydrogels are notable biomaterials in bioengineering and biotechnology due to their outstanding biocompatibility, good permeability to water-soluble metabolites, and the high swelling ratio. [1] Hydrogels are extensively used in regenerative medicine and tissue engineering, such as biomarker detection, [2] stem cell research, [3] and organ-on-a-chip (OOC) applications. Hydrogels are chemically or physically cross-linked natural or synthetic threedimensional (3D) networks that can form into various shapes and hold large amounts of water, which could be up to 4000% by dry weight, while they are hardly dissolved in water. [4] Their water retention properties are primarily because of the existence of hydrophilic groups in polymer chains such as amido, amino, carboxyl, and hydroxyl. The degree of swelling depends on the composition of the polymer, the density, and the Increasing demand for customized implants and tissue scaffolds requires advanced biomaterials and fabricating processes for fabricating three-dimensional (3D) structures that resemble the complexity of the extracellular matrix (ECM). Lately, biofabrication approaches such as cell-laden (soft) hydrogel 3D printing (3DP) have been of increasing interest in the development of 3D functional environments similar to natural tissues and organs. Hydrogels that resemble biological ECMs can provide mechanical support and signaling cues to cells to control their behavior. Although the capability of hydrogels to produce artificial ECMs can regulate cellular behavior, one of the major drawbacks of working with hydrogels is their inferior mechanical properties. Therefore, keeping and enhancing the mechanical integrity of fabricated scaffolds has become an essential matter for 3D hydrogel structures. Herein, 3D-printed hydrogel-based nanocomposites (NCs) are evaluated systematically in terms of introducing novel techniques for 3DP of hydrogel-based materials, properties, and biomedical applications.

Modern Approach to Testing the Biocompatibility of Osteochondral Scaffolds in Accordance with the 3Rs Principle─Preclinical In Vitro, Ex Vivo, and In Vivo Studies Using the Biphasic Curdlan-Based Biomaterial

“…The growing demand for biomaterials among society and the development of materials engineering have resulted in the fabrication of new biomaterials each year, which consist of both natural and synthetic polymers and are produced using increasingly modern production methods. 108 − 112 However, in order for a new biomaterial to be recognized as a promising candidate for use in regenerative medicine, it must undergo a series of tests confirming its usefulness and biological safety. In the case of biological research, in vivo experiments involving laboratory animals are an essential element confirming the biocompatibility of a biomaterial.…”

Mechano‐Adaptive Anti‐Swelling Hydrogels: Stable Motion‐Interfacing and Healthcare Monitoring

“…Breakthrough applications of anti-swelling hydrogels in implantable prosthetics are advancing the fields of biomimetic artificial cartilage and brain-computer interfaces (BCI). Through material science innovations, these applications address longstanding clinical challenges including mechanical instability, interface degradation, and biocompatibility issues [ 147,148 ]. In artificial cartilage design, hydrogels serve as ideal candidates due to their high water content, porous structure, and solidliquid biphasic properties, characteristics resembling natural cartilage.…”

Recent Advances in Poly(N‐isopropylacrylamide) Hydrogels and Derivatives as Promising Materials for Biomedical and Engineering Emerging Applications

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Hydrogels play a significant role in the medical field as they provide enhanced performance as drug carriers for cell and gene therapies, tissue engineering, and 3D-printed artificial organs, due to their soft condition as polymeric material and high biocompatibility. [1][2][3][4] Moreover, most of them are derived from biopolymers obtained by friendly and clinical-grade technology processes, such as bacterial fermentation and photosynthesis of plants and vegetables. [5] Hydrogels are waterswollen crosslinked polymer networks, highly capable of absorbing water (up to 100 times its weight) without dissolving on it.

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