Injectable hydrogels for cartilage and bone tissue engineering

Mei Liu,Zeeshan Ali,Chao Ma,Huan Yi,Song Li,Nongyue He,Xianbo Mou,Xin Zeng,Yan Deng

doi:10.1038/boneres.2017.14

Abstract

Tissue engineering has become a promising strategy for repairing damaged cartilage and bone tissue. Among the scaffolds for tissue-engineering applications, injectable hydrogels have demonstrated great potential for use as three-dimensional cell culture scaffolds in cartilage and bone tissue engineering, owing to their high water content, similarity to the natural extracellular matrix (ECM), porous framework for cell transplantation and proliferation, minimal invasive properties, and ability to match irregular defects. In this review, we describe the selection of appropriate biomaterials and fabrication methods to prepare novel injectable hydrogels for cartilage and bone tissue engineering. In addition, the biology of cartilage and the bony ECM is also summarized. Finally, future perspectives for injectable hydrogels in cartilage and bone tissue engineering are discussed.

Highlights

Cartilage and subchondral bone damage can be caused by a variety of conditions, such as trauma, arthritis, and sports-related injuries.[1,2,3,4] It has been reported that 60% of patients examined by knee arthroscopy exhibit cartilage damage, and ~ 15% of people over 60 years old have some clinical symptoms of such damage.[5,6] In particular, the self-healing of damaged cartilage is limited, owing to its lack of vascularization, innervation, lymphatic networks, and progenitor cells.[6,7,8,9,10,11,12] For bone tissue, despite its high vascularization, commonly used techniques for repair, such as autografting and allografting, are limited because of risks of donor-site morbidity, potential infection, and a high nonunion rate with host tissues.[13,14,15,16,17] Bone defects are one of the leading causes of morbidity and disability in elderly patients.[18]
Jin et al[159] have used horseradish peroxidase (HRP)-mediated co-cross-linking to form dextran– tyramine (Dex–TA) and heparin–tyramine injectable hydrogel conjugates whose swelling and mechanical properties can be controlled for cartilage tissueengineering applications
We summarized many novel injectable hydrogels prepared by a variety of biomaterial and fabrication techniques for cartilage- and bone tissueengineering applications

Summary

Introduction

Cartilage and subchondral bone damage can be caused by a variety of conditions, such as trauma, arthritis, and sports-related injuries.[1,2,3,4] It has been reported that 60% of patients examined by knee arthroscopy exhibit cartilage damage, and ~ 15% of people over 60 years old have some clinical symptoms of such damage.[5,6] In particular, the self-healing of damaged cartilage is limited, owing to its lack of vascularization, innervation, lymphatic networks, and progenitor cells.[6,7,8,9,10,11,12] For bone tissue, despite its high vascularization, commonly used techniques for repair, such as autografting and allografting, are limited because of risks of donor-site morbidity, potential infection, and a high nonunion rate with host tissues.[13,14,15,16,17] Bone defects are one of the leading causes of morbidity and disability in elderly patients.[18]. Various biomaterials and fabrication methods for developing injectable hydrogels for cartilage- and bone tissue-engineering applications are discussed.

Results

Conclusion