Prospect and retrospect of 3D bio-printing

3D printed scaffolds based on hyaluronic acid bioinks for tissue engineering: a review

Hyaluronic acid (HA) is widely distributed in human connective tissue, and its unique biological and physicochemical properties and ability to facilitate biological structure repair make it a promising candidate for three-dimensional (3D) bioprinting in the field of tissue regeneration and biomedical engineering. Moreover, HA is an ideal raw material for bioinks in tissue engineering because of its histocompatibility, non-immunogenicity, biodegradability, anti-inflammatory properties, anti-angiogenic properties, and modifiability. Tissue engineering is a multidisciplinary field focusing on in vitro reconstructions of mammalian tissues, such as cartilage tissue engineering, neural tissue engineering, skin tissue engineering, and other areas that require further clinical applications. In this review, we first describe the modification methods, cross-linking methods, and bioprinting strategies for HA and its derivatives as bioinks and then critically discuss the strengths, shortcomings, and feasibility of each method. Subsequently, we reviewed the practical clinical applications and outcomes of HA bioink in 3D bioprinting. Finally, we describe the challenges and opportunities in the development of HA bioink to provide further research references and insights.

Bibliometric and visualized analysis of 3D printing bioink in bone tissue engineering

Background: Applying 3D printed bioink to bone tissue engineering is an emerging technology for restoring bone tissue defects. This study aims to evaluate the application of 3D printing bioink in bone tissue engineering from 2010 to 2022 through bibliometric analysis, and to predict the hotspots and developing trends in this field. Methods: We retrieved publications from Web of Science from 2010 to 2022 on 8 January 2023. We examined the retrieved data using the bibliometrix package in R software, and VOSviewer and CiteSpace were used for visualizing the trends and hotspots of research on 3D printing bioink in bone tissue engineering. Results: We identified 682 articles and review articles in this field from 2010 to 2022. The journal Biomaterials ranked first in the number of articles published in this field. In 2016, an article published by Hölzl, K in the Biofabrication journal ranked first in number of citations. China ranked first in number of articles published and in single country publications (SCP), while America surpassed China to rank first in multiple country publications (MCP). In addition, a collaboration network analysis showed tight collaborations among China, America, South Korea, Netherlands, and other countries, with the top 10 major research affiliations mostly from these countries. The top 10 high-frequency words in this field are consistent with the field's research hotspots. The evolution trend of the discipline indicates that most citations come from Physics/Materials/Chemistry journals. Factorial analysis plays an intuitive role in determining research hotspots in this sphere. Keyword burst detection shows that chitosan and endothelial cells are emerging research hotspots in this field. Conclusion: This bibliometric study maps out a fundamental knowledge structure including countries, affiliations, authors, journals and keywords in this field of research from 2010 to 2022. This study fills a gap in the field of bibliometrics and provides a comprehensive perspective with broad prospects for this burgeoning research area.

Bioinks adapted for in situ bioprinting scenarios of defect sites: a review

In situ bioprinting provides a reliable solution to the problem of in vitro tissue culture and vascularization by printing tissue directly at the site of injury or defect and maturing the printed tissue using the natural cell microenvironment in vivo. As an emerging field, in situ bioprinting is based on computer-assisted scanning results of the defect site and is able to print cells directly at this site with biomaterials, bioactive factors, and other materials without the need to transfer prefabricated grafts as with traditional in vitro 3D bioprinting methods, and the resulting grafts can accurately adapt to the target defect site. However, one of the important reasons hindering the development of in situ bioprinting is the absence of suitable bioinks. In this review, we will summarize bioinks developed in recent years that can adapt to in situ printing scenarios at the defect site, considering three aspects: the in situ design strategy of bioink, the selection of commonly used biomaterials, and the application of bioprinting to different treatment scenarios.