Global hotspots and emerging trends in 3D bioprinting research

Experimental Study on Compatibility of Human Bronchial Epithelial Cells in Collagen-Alginate Bioink for 3D Printing

This paper reports an experimental study on the compatibility of human bronchial epithelial (HBE) cells in a collagen-alginate bioink. The compatibility was assessed using the culture well method with three bioink compositions prepared from a 10% alginate solution and neutralized TeloCol-10 mg/mL collagen stock solution. Cell viability, quantified by (live cell count-dead cell count)/live cell count within the HBE cell-laden hydrogel, was evaluated using the live/dead assay method from Day 0 to Day 6. Experimental results demonstrated that the collagen-alginate 4:1 bioink composition exhibited the highest cell viability on Day 6 (85%), outperforming the collagen-alginate 1:4 bioink composition and the alginate bioink composition, which showed cell viability of 75% and 45%, respectively. Additionally, the live cell count was highest for the collagen-alginate 4:1 bioink composition on Day 0, a trend that persisted through Days 1 to 6, underscoring its superior performance in maintaining cell viability and promoting cell proliferation. These findings show that the compatibility of HBE cells with the collagen-alginate 4:1 bioink composition was higher compared with the other two bioink compositions.

Artificial intelligence assisted preoperative planning and 3D-printing guiding frame for percutaneous screw reconstruction in periacetabular metastatic cancer patients

Background

The percutaneous screw reconstruction technique, known as the "Tripod Technique," has demonstrated favorable clinical outcomes in the management of metastatic periacetabular lesions, as evidenced by our prior investigations and corroborated by independent studies. Nevertheless, there is a steep learning curve in handling this technique, with possible complications such as intraarticular screw placement.

Methods

Preoperative pelvic CT scans were acquired before surgery and utilized for the guiding frame design. A convolutional neural network model was trained with annotated data to identify the starting point and trajectory of each potential screw. A model boundary intersection detection technology was used to determine the optimal diameter and length of each screw. A non-rigid registration technology was matched with a prefabricated model of the body surface to design personalized anchoring skin pads. Finally, a polylactic acid-based guiding frame for intraoperative was custom-made with a 3D printer.

Results

12 patients underwent a guiding frame-assisted Tripod procedure for treatment of periacetabular metastatic lesions. An intraoperative CT scan was performed in all cases to confirm screw trajectories. Among 36 screws that were implanted, 26 screws were implanted as designed. The remaining ten screws drifted, but all remained within the intra-osseous conduit without any complications. The mean surgical time was 1.22 h with the guiding frame compared with 2.3 h without the guiding frame. Following the surgical procedure, a noteworthy enhancement in pain management, as evidenced by a reduction in scores on the visual analog scale (p < 0.01), and an improvement in functional status, as assessed through the Eastern Cooperative Oncology Group score (p < 0.01), were observed when compared to the patient's pre-operative condition.

Conclusion

This proof-of-concept investigation demonstrates that the amalgamation of AI-assisted surgical planning and additive manufacturing can improve surgical accuracy and shorten surgical duration. While access to this technology is currently constrained during its early stages of development, it is anticipated that these limitations will diminish as the potential of AI and additive manufacturing in facilitating complex orthopedic procedures becomes more evident, leading to a surge in interest and adoption of this approach.

The application of 3D printing in dentistry: A bibliometric analysis from 2012 to 2023

STATEMENT OF PROBLEM

Three-dimensional (3D) printing has had extensive applications across dentistry, but a comprehensive bibliometric analysis relating to the application of 3D printing in dentistry is lacking.

PURPOSE

The purpose of this study was to conduct a comprehensive bibliometric analysis of the scientific literature concerning the application of 3D printing in dentistry from 2012 to 2023.

MATERIAL AND METHODS

The literature search was conducted in the Web of Science Core Collection Database. The retrieved literature data were downloaded as plain text file in "full record and cited references" format, with software programs (VOSviewer, CiteSpace, Biblioshiny, RStudio, Carrot2, and Microsoft Excel) used for bibliometric analysis and quantitative assessment.

RESULTS

The bibliometric analysis incorporated 1911 publications. Revilla-León, Marta was the most productive author. Zurich University had the highest number of publications and citations. The United States dominated the research landscape with the highest publication volume and H-index. The Journal of Prosthetic Dentistry was the leading journal in both publication volume and citation frequency. Co-occurrence analysis of keyword and co-cited analysis of reference indicated a robust research environment, characterized by a strong focus on the pursuit of accuracy in dental restorative solutions, biocompatibility of materials, and clinical applications.

CONCLUSIONS

Research on 3D printing in the field of dentistry continues to grow. Collaborations with leading organizations and countries have been established, with Revilla-León, Marta et al playing a pivotal role. Top journals represented included the Journal of Prosthetic Dentistry and Dental Materials. Main research domain resided in prosthodontics and implantology. Hot research topics included improvements in accuracy, dental materials, and clinical applications centered on implant guide design.

Visualization analysis of research hotspots and trends on gastrointestinal tumor organoids

BACKGROUND

Gastrointestinal tumor organoids serve as an effective model for simulating cancer in vitro and have been applied in basic biology and preclinical research. Despite over a decade of development and increasing research achievements in this field, a systematic and comprehensive analysis of the research hotspots and future trends is lacking.

AIM

To address this problem by employing bibliometric tools to explore the publication years, countries/regions, institutions, journals, authors, keywords, and references in this field.

METHODS

The literature was collected from Web of Science databases. CiteSpace-6.2R4, a widely used bibliometric analysis software package, was used for institutional analysis and reference burst analysis. VOSviewer 1.6.19 was used for journal co-citation analysis, author co-authorship and co-citation analysis. The 'online platform for bibliometric analysis (https://bibliometric.com/app)' was used to assess the total number of publications and the cooperation relationships between countries. Finally, we employed the bibliometric R software package (version R.4.3.1) in R-studio, for a comprehensive scientific analysis of the literature.

RESULTS

Our analysis included a total of 1466 publications, revealing a significant yearly increase in articles on the study of gastrointestinal tumor organoids. The United States (n = 393) and Helmholtz Association (n = 93) have emerged as the leading countries and institutions, respectively, in this field, with Hans Clevers and Toshiro Sato being the most contributing authors. The most influential journal in this field is Gastroenterology. The most impactful reference is "Long term expansion of epithelial organs from human colon, adenoma, adenocarcinoma, and Barrett's epithelium". Keywords analysis and citation burst analysis indicate that precision medicine, disease modeling, drug development and screening, and regenerative medicine are the most cutting-edge directions. These focal points were further detailed based on the literature.

CONCLUSION

This bibliometric study offers an objective and quantitative analysis of the research in this field, which can be considered as an important guide for next scientific research.

Sculpting the future: A narrative review of 3D printing in plastic surgery and prosthetic devices

Background and Aims

The advent of 3D printing has revolutionized plastic surgery and prosthetic devices, providing personalized solutions for patients with traumatic injuries, deformities, and appearance-related conditions. This review offers a comprehensive overview of 3D printing's applications, advantages, limitations, and future prospects in these fields.

Methods

A literature search was conducted in PubMed, Google Scholar, and Scopus for studies on 3D printing in plastic surgery.

Results

3D printing has significantly contributed to personalized medical interventions, with benefits like enhanced design flexibility, reduced production time, and improved patient outcomes. Using computer-aided design (CAD) software, precise models tailored to a patient's anatomy can be created, ensuring better fit, functionality, and comfort. 3D printing allows for intricate geometries, leading to improved aesthetic outcomes and patient-specific prosthetic limbs and orthoses. The historical development of 3D printing, key milestones, and breakthroughs are highlighted. Recent progress in bioprinting and tissue engineering shows promising applications in regenerative medicine and transplantation. The integration of AI and automation with 3D printing enhances surgical planning and outcomes. Emerging trends in patient-specific treatment planning and precision medicine are potential game-changers. However, challenges like technical considerations, economic implications, and ethical issues exist. Addressing these challenges and advancing research in materials, design processes, and long-term outcomes are crucial for widespread adoption.

Conclusion

The review underscores the increasing adoption of 3D printing in healthcare and its impact on plastic surgery and prosthetic devices. It emphasizes the importance of evaluating the current state and addressing knowledge gaps through future research to foster further advancements.

A review of biomacromolecule-based 3D bioprinting strategies for structure-function integrated repair of skin tissues

When skin is damaged or affected by diseases, it often undergoes irreversible scar formation, leading to aesthetic concerns and psychological distress for patients. In cases of extensive skin defects, the patient's life can be severely compromised. In recent years, 3D printing technology has emerged as a groundbreaking approach to skin tissue engineering, offering promising solutions to various skin-related conditions. 3D bioprinting technology enables the precise fabrication of structures by programming the spatial arrangement of cells within the skin tissue and subsequently printing skin replacements either in a 3D bioprinter or directly at the site of the defect. This study provides a comprehensive overview of various biopolymer-based inks, with a particular emphasis on chitosan (CS), starch, alginate, agarose, cellulose, and fibronectin, all of which are natural polymers belonging to the category of biomacromolecules. Additionally, it summarizes artificially synthesized polymers capable of enhancing the performance of these biomacromolecule-based bioinks, thereby composing hybrid biopolymer inks aimed at better application in skin tissue engineering endeavors. This review paper examines the recent advancements, characteristics, benefits, and limitations of biological 3D bioprinting techniques for skin tissue engineering. By utilizing bioinks containing seed cells, hydrogels with bioactive factors, and biomaterials, complex structures resembling natural skin can be accurately fabricated in a layer-by-layer manner. The importance of biological scaffolds in promoting skin wound healing and the role of 3D bioprinting in skin tissue regeneration processes is discussed. Additionally, this paper addresses the challenges and constraints associated with current 3D bioprinting technologies for skin tissue and presents future perspectives. These include advancements in bioink formulations, full-thickness skin bioprinting, vascularization strategies, and skin appendages bioprinting.

Bibliometric analysis of global research on human organoids

The emergence and rapid development of human organoids have provided the possibility to replace animal models in treating human diseases. Intelligence studies help focus on research hotspots and address key mechanistic issues. Currently, few comprehensive studies describe the characteristics of human organoid research. In this study, we extracted 8,591 original articles on organoids from the Web of Science core collection database over the past two decades and conducted intelligence analysis using CiteSpace. The number of publications in this field has experienced rapid growth in the last ten years (almost 70-fold increase since 2009). The United States, China, Germany, Netherlands, and UK have strong collaborations in publishing articles. Clevers Hans, Van Der Laan, Jason R Spence, and Sato Toshiro have made significant contributions to advancing progress in this field. Clustering and burst analysis categorized research hotspots into tissue model and functional construction, intercellular signaling, immune mechanisms, and tumor metastasis. Organoid research in highly cited articles covers four major areas: basic research (38%), involving stem cell developmental processes and cell-cell interactions; biobanking (10%), with a focus on organoid cultivation; precision medicine (16%), emphasizing cell therapy and drug development; and disease modeling (36%), including pathogen analysis and screening for disease-related genetic variations. The main obstacles currently faced in organoid research include cost and technology, vascularization of cells, immune system establishment, international standard protocols, and limited availability of high-quality clinical trial data. Future research will focus on cost-saving measures, technology sharing, development of international standards, and conducting high-level clinical trials.

GelMA synthesis and sources comparison for 3D multimaterial bioprinting

Gelatin Methacryloyl (GelMA) is one of the most used biomaterials for a wide range of applications, such as drug delivery, disease modeling and tissue regeneration. GelMA is obtained from gelatin, which can be derived from different sources (e.g., bovine skin, and porcine skin), through substitution of reactive amine and hydroxyl groups with methacrylic anhydride (MAA). The degree of functionalization (DoF) can be tuned by varying the MAA amount used; thus, different protocols, with different reaction efficiency, have been developed, using various alkaline buffers (e.g., phosphate-buffered saline, DPBS, or carbonate-bicarbonate solution). Obviously, DoF modulation has an impact on the final GelMA properties, so a deep investigation on the features of the obtained hydrogel must be carried on. The purpose of this study is to investigate how different gelatin sources and synthesis methods affect GelMA properties, as literature lacks direct and systematic comparisons between these parameters, especially between synthesis methods. The final aim is to facilitate the choice of the source or synthesis method according to the needs of the desired application. Hence, chemical and physical properties of GelMA formulations were assessed, determining the DoFs, mechanical and viscoelastic properties by rheological analysis, water absorption by swelling capacity and enzymatic degradation rates. Biological tests with lung adenocarcinoma cells (A549) were performed. Moreover, since 3D bioprinting is a rapidly evolving technology thanks to the possibility of precise deposition of cell-laden biomaterials (bioinks) to mimic the 3D structures of several tissues, the potential of different GelMA formulations as bioinks have been tested with a multi-material approach, revealing its printability and versatility in various applications.

Emergent trends in organ-on-a-chip applications for investigating metastasis within tumor microenvironment: A comprehensive bibliometric analysis

Background

With the burgeoning advancements in disease modeling, drug development, and precision medicine, organ-on-a-chip has risen to the forefront of biomedical research. Specifically in tumor research, this technology has exhibited exceptional potential in elucidating the dynamics of metastasis within the tumor microenvironment. Recognizing the significance of this field, our study aims to provide a comprehensive bibliometric analysis of global scientific contributions related to organ-on-a-chip.

Methods

Publications pertaining to organ-on-a-chip from 2014 to 2023 were retrieved at the Web of Science Core Collection database. Rigorous analyses of 2305 articles were conducted using tools including VOSviewer, CiteSpace, and R-bibliometrix.

Results

Over the 10-year span, global publications exhibited a consistent uptrend, anticipating continued growth. The United States and China were identified as dominant contributors, characterized by strong collaborative networks and substantial research investments. Predominant institutions encompass Harvard University, MIT, and the Chinese Academy of Sciences. Leading figures in the domain, such as Dr. Donald Ingber and Dr. Yu Shrike Zhang, emerge as pivotal collaboration prospects. Lab on a Chip, Micromachines, and Frontiers in Bioengineering and Biotechnology were the principal publishing journals. Pertinent keywords encompassed Microfluidic, Microphysiological System, Tissue Engineering, Organoid, In Vitro, Drug Screening, Hydrogel, Tumor Microenvironment, and Bioprinting. Emerging research avenues were identified as "Tumor Microenvironment and Metastasis," "Application of organ-on-a-chip in drug discovery and testing" and "Advancements in personalized medicine applications".

Conclusion

The organ-on-a-chip domain has demonstrated a transformative impact on understanding disease mechanisms and drug interactions, particularly within the tumor microenvironment. This bibliometric analysis underscores the ever-increasing importance of this field, guiding researchers and clinicians towards potential collaborative avenues and research directions.

Bibliometric and Visualization Analysis of Biomechanical Research on Lumbar Intervertebral Disc

Background

Biomechanical research on the lumbar intervertebral disc (IVD) provides valuable information for the diagnosis, treatment, and prevention of related diseases, and has received increasing attention. Using bibliometric methods and visualization techniques, this study investigates for the first time the research status and development trends in this field, with the aim of providing guidance and support for subsequent research.

Methods

The Science Citation Index Expanded (SCI-Expanded) within the Web of Science Core Collection (WoSCC) database was used as the data source to select literature published from 2003 to 2022 related to biomechanical research on lumbar IVD. VOSviewer 1.6.19 and CiteSpace 6.2.R2 visualization software, as well as the online analysis platform of literature metrology, were utilized to generate scientific knowledge maps for visual display and data analysis.

Results

The United States is the most productive country in this field, with the Ulm University making the largest contribution. Wilke HJ is both the most prolific author and one of the highly cited authors, while Adams MA is the most cited author. Spine, J Biomech, Eur Spine J, Spine J, and Clin Biomech are not only the journals with the highest number of publications, but also highly cited journals. The main research topics in this field include constructing and validating three-dimensional (3D) finite element model (FEM) of lumbar spine, measuring intradiscal pressure, exploring the biomechanical effects and related risk factors of lumbar disc degeneration, studying the mechanical responses to different torque load combinations, and classifying lumbar disc degeneration based on magnetic resonance images (MRI), which are also the hot research themes in recent years.

Conclusion

This study systematically reviews the knowledge system and development trends in the field of biomechanics of lumbar IVD, providing valuable references for further research.

Perspectives on Scaffold Designs with Roles in Liver Cell Asymmetry and Medical and Industrial Applications by Using a New Type of Specialized 3D Bioprinter

Cellular asymmetry is an important element of efficiency in the compartmentalization of intracellular chemical reactions that ensure efficient tissue function. Improving the current 3D printing methods by using cellular asymmetry is essential in producing complex tissues and organs such as the liver. The use of cell spots containing at least two cells and basement membrane-like bio support materials allows cells to be tethered at two points on the basement membrane and with another cell in order to maintain cell asymmetry. Our model is a new type of 3D bioprinter that uses oriented multicellular complexes with cellular asymmetry. This novel approach is necessary to replace the sequential and slow processes of organogenesis with rapid methods of growth and 3D organ printing. The use of the extracellular matrix in the process of bioprinting with cells allows one to preserve the cellular asymmetry in the 3D printing process and thus preserve the compartmentalization of biological processes and metabolic efficiency.