Collagen‐Tannic Acid Spheroids for β‐Cell Encapsulation Fabricated Using a 3D Bioprinter

Abstract

Type 1 Diabetes results from autoimmune response elicited against β‐cell antigens. Nowadays, insulin injections remain the leading therapeutic option. However, injection treatment fails to emulate the highly dynamic insulin release that β‐cells provide. 3D cell‐laden microspheres have been proposed during the last years as a major platform for bioengineering insulin‐secreting constructs for tissue graft implantation and a model for in vitro drug screening platforms. Current microsphere fabrication technologies have several drawbacks: the need for an oil phase containing surfactants, diameter inconsistency of the microspheres, and high time‐consuming processes. These technologies have widely used alginate for its rapid gelation, high processability, and low cost. However, its low biocompatible properties do not provide effective cell attachment. This study proposes a high‐throughput methodology using a 3D bioprinter that employs an ECM‐like microenvironment for effective cell‐laden microsphere production to overcome these limitations. Crosslinking the resulting microspheres with tannic acid prevents collagenase degradation and enhances spherical structural consistency while allowing the diffusion of nutrients and oxygen. The approach allows customization of microsphere diameter with extremely low variability. In conclusion, a novel bio‐printing procedure is developed to fabricate large amounts of reproducible microspheres capable of secreting insulin in response to extracellular glucose stimuli.

Preparation strategy of hydrogel microsphere and its application in skin repair

“…In recent years, 3D printing technology was developed for the preparation of various hydrogel microspheres. To overcome the limitation of current microsphere fabrication technologies such as the need for an oil phase containing surfactants, a 3D bioprinter was employed to prepare a cell-laden collagen microsphere and crosslinked with tannic acid ( Figure 5 ) ( Clua-Ferre et al, 2022 ). The 3D printing approach was developed with a high-throughput methodology for the cell-laden microsphere capable of secreting insulin.…”

“…The images of collagen crosslinked with TA spheroid and collagen control spheroid. Scale bar = 10 mm ( Clua-Ferre et al, 2022 ).…”

Cell Encapsulation and 3D Bioprinting for Therapeutic Cell Transplantation

“…Unfortunately, several drawbacks limit its application in the clinical field. These impediments include the lack of compatible cadaveric donors, the requirement for immunosuppressants, and the loss of islets due to lack of oxygenation and vascularization . Using living cells for 3D bioprinting as one of the latest advancements in biomedical engineering is a promising option to solve the aforementioned challenges .…”

“…These impediments include the lack of compatible cadaveric donors, the requirement for immunosuppressants, and the loss of islets due to lack of oxygenation and vascularization. 257 Using living cells for 3D bioprinting as one of the latest advancements in biomedical engineering is a promising option to solve the aforementioned challenges. 258 The application of 3D bioprinting for T1D treatment is nascent; hence, there are not many published reports describing the applications of 3D bioprinting for T1D treatment.…”

Advances in Three Dimensional Bioprinting for Wound Healing: A Comprehensive Review

“…However, in bioprinting, numerous bioink parameters such as viscosity, shear thinning, viscoelasticity, biodegradation, crosslinking, and cellular adhesion must be chosen. These characteristics are crucial for achieving the required structures [242][243][244].…”