3D bioprinting of tyramine modified hydrogels under visible light for osteochondral interface

Abstract

Recent advancements in tissue engineering have demonstrated a great potential for the fabrication of three-dimensional tissue structures such as cartilage and bone. However, achieving structural integrity between different tissues and fabricating tissue interfaces are still great challenges. In this study, an in situ crosslinked hybrid, multi-material three-dimensional (3D) bioprinting approach was used for the fabrication of hydrogel structures based on an aspiration-extrusion microcapillary method. Different cell-laden hydrogels were aspirated in the same microcapillary glass and deposited in the desired geometrical and volumetric arrangement directly from a computer model. Alginate and carboxymethyl cellulose (CMC) were modified with tyramine to enhance cell bioactivity and mechanical properties of human bone marrow Mesenchymal Stem Cells (hBMSC)-laden bioinks. Hydrogels were prepared for extrusion by gelling in microcapillary glass utilizing an in situ crosslink approach with ruthenium (Ru) and sodium persulfate (SPS) photo-initiating mechanisms under visible light. The developed bioinks were then bioprinted in precise gradient composition for cartilage-bone tissue interface using microcapillary bioprinting technique. The biofabricated constructs were co-cultured in chondrogenic/osteogenic culture media for three weeks. After cell viability and morphology evaluations of the bioprinted structures, biochemical and histological analyses, and a gene expression analysis for the bioprinted structure were carried out. Analysis of cartilage and bone formation based on cell alignment and histological evaluation indicated that mechanical cues in conjunction with chemical cues successfully induced MSC differentiation into chondrogenic and osteogenic tissues with a controlled interface.

Silver nitrate-assisted photo-crosslinking for enhancing the mechanical properties of an alginate/silk fibroin-based 3D scaffold

“…Photocrosslinking using SPS/Rubpy resulted in an interpenetrating polymer network connected by dityrosine bonds, using the phenolic side chains of tyrosine residues and chemically grafted tyramine [25,31]. The incorporation of tyramine moieties enhances the density of adhesive sites, bioactivity, cell attachment, elasticity, and mechanical strength of the scaffolds [32].…”

3D printed osteochondral scaffolds: design strategies, present applications and future perspectives

“…Researches in recent years have combined 3D printing technology with other techniques aimed at preparing scaffolds with a continuous gradient distribution of material and/or structure at the interface ( Idaszek et al, 2019 ; Senturk et al, 2023 ; Wei et al, 2023 ). The interface of this kind scaffold is usually formed by the fusion of cartilage layer and bone layer material, so the binding force at the interface junction is relatively strong.…”

“…Different hydrogels containing cells were sucked into the same microcapillary glass, and then the hydrogels were printed into OC scaffolds with precise gradient components using microcapillary bioprinting. In vitro experiments had shown that the scaffolds successfully induce the differentiation of MSC into chondrogenic and osteoblastic tissues with controlled interfaces ( Senturk et al, 2023 ). Joanna et al combined EP with microfluidics, using a mixed doped alginate-based solution.…”

Multimaterial Hydrogel 3D Printing

“…This technology was adopted by Senturk et al to fabricate gradient osteochondral interfaces with tyramine-modified alginate and carboxymethyl cellulose inks. [177] A major problem often encountered in multimaterial hydrogel DIW printing is low resolution due to inter-layer seepage. This is an unfortunate, yet expected, consequence of hydrogels being low viscosity materials with high liquid content.…”