Injectable In Situ Crosslinking Hydrogel for Autologous Fat Grafting
Journal article, 2023

Autologous fat grafting is hampered by unpredictable outcomes due to high tissue resorption. Hydrogels based on enzymatically pretreated tunicate nanocellulose (ETC) and alginate (ALG) are biocompatible, safe, and present physiochemical properties capable of promoting cell survival. Here, we compared in situ and ex situ crosslinking of ETC/ALG hydrogels combined with lipoaspirate human adipose tissue (LAT) to generate an injectable formulation capable of retaining dimensional stability in vivo. We performed in situ crosslinking using two different approaches; inducing Ca2+ release from CaCO3 microparticles (CMPs) and physiologically available Ca2+ in vivo. Additionally, we generated ex situ-crosslinked, 3D-bioprinted hydrogel-fat grafts. We found that in vitro optimization generated a CMP-crosslinking system with comparable stiffness to ex situ-crosslinked gels. Comparison of outcomes following in vivo injection of each respective crosslinked hydrogel revealed that after 30 days, in situ crosslinking generated fat grafts with less shape retention than 3D-bioprinted constructs that had undergone ex situ crosslinking. However, CMP addition improved fat-cell distribution and cell survival relative to grafts dependent on physiological Ca2+ alone. These findings suggested that in situ crosslinking using CMP might promote the dimensional stability of injectable fat-hydrogel grafts, although 3D bioprinting with ex situ crosslinking more effectively ensured proper shape stability in vivo.



in situ crosslinking

3D bioprinting

soft tissue reconstruction


Kristin Oskarsdotter

University of Gothenburg

Catherine T. Nordgård

Norwegian University of Science and Technology (NTNU)

Peter Apelgren

University of Gothenburg

Sahlgrenska University Hospital

Karin Säljö

Sahlgrenska University Hospital

University of Gothenburg

Anita A. Solbu

Norwegian University of Science and Technology (NTNU)

Edwin Eliasson

Sahlgrenska University Hospital

Sanna Sämfors

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Henriette E.M. Sætrang


Lise Cathrine Asdahl


Eric M. Thompson

University of Bergen

Ocean TuniCell AS

Christofer Troedsson

Ocean TuniCell AS

Stina Simonsson

Sahlgrenska University Hospital

Berit Løkensgard Strand

Norwegian University of Science and Technology (NTNU)

Paul Gatenholm


Lars Kölby

Sahlgrenska University Hospital

University of Gothenburg


23102861 (eISSN)

Vol. 9 10 813

Subject Categories


Biochemistry and Molecular Biology





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