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3.6. Bibliometric analysis of keywords signaling a shift toward practical applications of organoids
in tissue engineering and regenerative medicine.
Figure 9A displays keywords with a frequency greater than
three. From a total of 1,859 keywords, 210 high-frequency The keywords were further grouped into seven
keywords were identified and grouped into five clusters. clusters (Figure 9C), with #0 “Regenerative Medicine”
For further analysis, we focused on four major clusters being the largest and most central cluster. This finding
among these five: (i) Green Cluster: Concentrates on stem highlights the dominant focus on regenerative medicine
cell biology and differentiation, with terms, such as “stem and its application in organoid development for tissue
cells” and “niche” emphasizing stem cell behavior and regeneration. Cluster #1, “Bone Regeneration,” reflects
growth in organoid systems; (ii) Blue Cluster: Emphasizes the growing interest in using organoids for bone healing
tissue engineering, scaffolds, and bioprinting. The and repair, while Cluster #2 “Bone Marrow Organoids,”
frequent appearance of terms such as “tissue engineering,” emphasizes the role of bone marrow organoids in
“hydrogels,” and “bioprinting” highlights the critical role mimicking bone microenvironments for both research and
of advanced materials in organoid development; (iii) Red clinical use. Other key clusters include #3 “Differentiation,”
Cluster: Focused on genetic and molecular aspects, #4 “Extracellular Matrix,” #5 “Expression,” and #6 “Protein-
particularly in the context of disease models, such as cancer Based Culture,” underlining the importance of molecular
(e.g., “osteosarcoma”). Keywords such as “personalized mechanisms, cellular environments, and culture techniques
medicine” and “immunotherapy” underscore the research in organoid development. The burst word analysis revealed
into therapeutic applications; and (iv) Yellow Cluster: trending research topics over specific periods, with the
Highlights research on chondrocytes, osteoblasts, and top two keywords showing the strongest citation bursts, as
matrix, focusing on bone and cartilage development. presented in Figure 9D.
Keywords, such as “differentiation,” “chondrocytes,” and The timeline visualization illustrates the temporal
“expression” indicate the translational potential of organoid trends and shifts in research keywords. As shown in
models in bone repair and tissue regeneration. Figure 9B Figure 10, around 2015, terms, such as “in vitro” and
provides a temporal overlay, indicating the recency of “bone” were predominant, indicating early-stage research
research developments. Darker-colored terms, from 2019 focused on in vitro models and bone regeneration. By
to 2020, represent earlier research, while lighter-colored 2020, the focus shifted toward advanced technologies,
terms (2022–2023) reflect more recent trends. Keywords, such as “bioprinting,” “hydrogels,” and “tissue engineering,”
such as “bone tissue engineering,” “mineralization,” and reflecting an increasing interest in developing sophisticated
“scaffolds” have gained more attention in recent years, materials and 3D bioprinting techniques for organoid

A B

C D

Figure 9. Bibliometric analysis of keywords. (A) Co-occurrence analysis of 210 keywords related to bone/cartilage organoids. (B) Overlay visualization
map of keyword co-occurrences. (C) Clustering analysis of the keyword network using CiteSpace. (D) Citation burst analysis of keywords.

Volume 1 Issue 3 (2025) 9 doi: 10.36922/or.8295