Hydrogel-Colloid Composite Bioinks for Targeted Tissue-Printing

Abstract

The development of extrusion-based bioprinting for tissue engineering is conditioned by the design of bioinks displaying adequate printability, shape stability and postprinting bioactivity. In this context, simple bioink formulations, made of cells supported by a polymer matrix, often lack the necessary versatility. To address this issue, intense research work has been focused on introducing colloidal particles into the ink formulation. By creating weak crosslinks between polymer chains, added particles modify the rheology and mechanical behavior of bioinks to improve their printability and structural integrity. Additionally, nano-and microscopic particles display composition-and structure-specific properties that can affect the cellular behavior and enhance the formation of tissue within the printed material. This review offers a comprehensive picture of the role of colloids in bioprinting from a physicochemical and biological perspective. As such, it provides guidance on devising adaptable bioinks for the fabrication of biomimetic tissues.

Semi-solid extrusion 3D printing in drug delivery and biomedicine: Personalised solutions for healthcare challenges

“…Therefore, rheological assessment of the material before 3DP may be useful for quality control of successive batches, as also demonstrated for formulation II (89). It is interesting to note that the printability region for cellulose ether-based materials occurred for G' values in the region of 10 4 -10 5 Pa at rest, which is in the 10 3 -10 5 Pa interval found as suitable by other authors testing pastes or bioinks containing dispersed colloidal components (90)(91)(92)(93). Therefore, such a G' value interval together with shearthinning behavior may be used as the first tentative targets to reach when preparing drug-loaded soft materials for SSE 3DP.…”

Smart Bioinks for the Printing of Human Tissue Models

“…A colloid is a dispersion of one or more substances suspended in a liquid, forming a system with two separate phases [ 91 ]. Colloids can be heterogeneous mixtures of nano- or microscopic particles of various shapes such as spheres, platelets, crystals, rods, and fibres [ 92 ]. Michel and Auzely-Velty give an overview of recent research on colloid composite bioinks for extrusion printing.…”

“…Michel and Auzely-Velty give an overview of recent research on colloid composite bioinks for extrusion printing. They discuss how embedded colloids influence the rheology of bioinks and the mechanical characteristics of printed hydrogels, as well as the critical role of colloidal materials in regulating cell fate and adding novel functionalities to design sophisticated tissues [ 92 ]. Insights and methods for choosing the right colloidal components in the formation of composite bioinks are also presented.…”

“…Antioxidant properties, drug release, and electroactivity can all help guide and enhance synthetic tissue formation. For all of these reasons, it was concluded that colloidal materials serve a critical role in the creation of novel bioinks with improved printability that can produce complex tissue constructs [ 92 ].…”

Hierarchical Incorporation of Surface-Functionalized Laponite Clay Nanoplatelets with Type I Collagen Matrix

“…Moreover, they possess excellent biocompatibility, high specific surface area, and a bioactive interface and can easily biodegrade into nontoxic products . These features can result in a rich array of possible interactions between the clay and the biopolymers or polymers and thus are conducive to the incorporation into the biopolymeric or polymeric matrix for versatile applications, such as drug delivery nanoplatforms, − tissue engineering, gas delivery carrier, and packaging materials . They have also been introduced into acidic collagen solutions for fabrication of collagen/clay nanocomposite films for food packaging .…”