Functional and morphological studies of in vivo vascularization of 3D-bioprinted human fat grafts
Journal article, 2021

Three-dimensional (3D) bioprinting offers the ability to design and biofabricate 3D structures based on autologous fat; however, the lack of vascularization in larger 3D-bioprinted constructs represents a limiting factor that hampers translation of this technology from bench to bedside. 3D bioprinting using microfractured fat mixed with nanocellulose–alginate hydrogel can promote vascularization through connections of fragments of vessels included in the fat. In this study, we determined the perfusion and diffusion characteristics of 3D-bioprinted fat constructs using magnetic resonance imaging (MRI) and assessed correlations between perfusion and angiogenesis within the printed constructs. Microfractured human fat from liposuction was printed with tunicate nanocellulose–alginate hydrogel, followed by transplantation of the constructs (10 × 10 × 3 mm) into nude mice that underwent longitudinal MRI for up to 99 days. Confirmation of vascularization was undertaken using immunohistochemical and histologic analyses. Before implantation, the constructs contained abundant fat tissue and fragments of human blood vessels (CD31+ and Ku80+), with subsequent in vivo MRI analysis following transplantation indicating low perfusion and suggesting their continued survival mainly by diffusion. Additionally, we observed a high diffusion coefficient (~2 × 10−3 mm2/s) that was preserved throughout the observation period. Following explantation, evaluation revealed that the constructs displayed preserved histology along with a mixture of human (Ku80+) and murine (Ku80−) erythrocyte-containing vessels. These results demonstrated successful interconnection of blood-vessel fragments from microfractured human fat via angiogenesis to form a vascular network with the host circulation, thereby confirming vascularization of the 3D-bioprinted fat constructs.

MRI

Vascularization

Fat tissue

3D bioprinting

Author

Matteo Amoroso

University of Gothenburg

Peter Apelgren

University of Gothenburg

Karin Säljö

University of Gothenburg

Mikael Montelius

Sahlgrenska University Hospital

Linnea Strid Orrhult

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Paul Gatenholm Group

Mona Engström

University of Gothenburg

Paul Gatenholm

Wallenberg Wood Science Center (WWSC)

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Paul Gatenholm Group

Lars Kölby

University of Gothenburg

Bioprinting

2405-8866 (ISSN)

Vol. 23 e00162

Subject Categories

Bioengineering Equipment

Pharmacology and Toxicology

Radiology, Nuclear Medicine and Medical Imaging

Areas of Advance

Health Engineering

DOI

10.1016/j.bprint.2021.e00162

More information

Latest update

8/6/2021 1