bims-biprem Biomed News
on Bioprinting for regenerative medicine
Issue of 2024‒08‒18
seven papers selected by
Seerat Maqsood, University of Teramo



  1. Biomacromolecules. 2024 Aug 12.
      Current bone repair methods have limitations, prompting the exploration of innovative approaches. Tissue engineering emerges as a promising solution, leveraging biomaterials to craft scaffolds replicating the natural bone environment, facilitating cell growth and differentiation. Among fabrication techniques, three-dimensional (3D) printing stands out for its ability to tailor intricate scaffolds. Silk proteins (SPs), known for their mechanical strength and biocompatibility, are an excellent choice for engineering 3D-printed bone tissue engineering (BTE) scaffolds. This article comprehensively reviews bone biology, 3D printing, and the unique attributes of SPs, specifically detailing criteria for scaffold fabrication such as composition, structure, mechanics, and cellular responses. It examines the structural, mechanical, and biological attributes of SPs, emphasizing their suitability for BTE. Recent studies on diverse 3D printing approaches using SPs-based for BTE are highlighted, alongside advancements in their 3D and four-dimensional (4D) printing and their role in osteo-immunomodulation. Future directions in the use of SPs for 3D printing in BTE are outlined.
    DOI:  https://doi.org/10.1021/acs.biomac.4c00540
  2. ACS Appl Bio Mater. 2024 Aug 15.
      Hydrogel microfibers are hydrogel materials engineered into fiber structures. Techniques such as wet spinning, microfluidic spinning, and 3D bioprinting are often used to prepare microfibers due to their ability to precisely control the size, morphology, and structure of the microfibers. Microfibers with different structural morphologies have different functions; they provide a flow-through culture environment for cells to improve viability, and can also be used to induce the differentiation of cells such as skeletal muscle and cardiac muscle cells to eventually form functional organs in vitro through special morphologies. This Review introduces recent advances in microfluidics, 3D bioprinting, and wet spinning in the preparation of microfibers, focusing on the materials and fabrication methods. The applications of microfibers in tissue engineering are highlighted by summarizing their contributions in engineering biomimetic blood vessels, vascularized tissues, bone, heart, pancreas, kidney, liver, and fat. Furthermore, applications of engineered fibers in tissue repair and drug screening are also discussed.
    Keywords:  3D bioprinting; microfibers; microfluidic spinning; tissue engineering; wet spinning
    DOI:  https://doi.org/10.1021/acsabm.4c00615
  3. Polymers (Basel). 2024 Jul 26. pii: 2131. [Epub ahead of print]16(15):
      Conductive hydrogels, known for their flexibility, biocompatibility, and conductivity, have found extensive applications in fields such as healthcare, environmental monitoring, and soft robotics. Recent advancements in 3D printing technologies have transformed the fabrication of conductive hydrogels, creating new opportunities for sensing applications. This review provides a comprehensive overview of the advancements in the fabrication and application of 3D-printed conductive hydrogel sensors. First, the basic principles and fabrication techniques of conductive hydrogels are briefly reviewed. We then explore various 3D printing methods for conductive hydrogels, discussing their respective strengths and limitations. The review also summarizes the applications of 3D-printed conductive hydrogel-based sensors. In addition, perspectives on 3D-printed conductive hydrogel sensors are highlighted. This review aims to equip researchers and engineers with insights into the current landscape of 3D-printed conductive hydrogel sensors and to inspire future innovations in this promising field.
    Keywords:  3D printing; application; conductive hydrogels; fabrication; sensors
    DOI:  https://doi.org/10.3390/polym16152131
  4. Biofabrication. 2024 Aug 09.
      Gallbladder carcinoma (GBC) is a malignant hepatobiliary cancer characterized by an intricate tumor microenvironments (TME) and heterogeneity. The traditional GBC 2D culture models cannot faithfully recapitulate the characteristics of the TME. Three-dimensional (3D) bioprinting enables the establishment of high-throughput and high-fidelity multicellular GBC models. In this study, we designed a concentric cylindrical tetra-culture model to reconstitute the spatial distribution of cells in tumor tissue, with the inner portion containing GBC cells, and the outer ring containing a mixture of endothelial cells, fibroblasts, and macrophages. We confirmed the survival, proliferation, biomarker expression and gene expression profiles of GBC 3D tetra-culture models. Hematoxylin-eosin (HE) and immunofluorescence staining verified the morphology and robust expression of GBC/endothelial/fibroblast/macrophage biomarkers in GBC 3D tetra-culture models. Single-cell RNA sequencing revealed two distinct subtypes of GBC cells within the model, glandular epithelial and squamous epithelial cells, suggesting the mimicry of intratumoral heterogeneity. Comparative transcriptome profile analysis among various in vitro models revealed that cellular interactions and the TME in 3D tetra-culture models reshaped the biological processes of tumor cells to a more aggressive phenotype. GBC 3D tetra-culture models restored the characteristics of the TME as well as intratumoral heterogeneity. Therefore, this model is expected to have future applications in tumor biology research and antitumor drug development.
    Keywords:  3D bioprinting; gallbladder carcinoma; in vitro model; intratumoral heterogeneity; tumor microenvironment
    DOI:  https://doi.org/10.1088/1758-5090/ad6d8c
  5. Diagnostics (Basel). 2024 Jul 31. pii: 1658. [Epub ahead of print]14(15):
      The use of 3D-printed models in simulation-based training and planning for vascular surgery is gaining interest. This study aims to provide an overview of the current applications of 3D-printing technologies in vascular surgery. We performed a systematic review by searching four databases: PubMed, Web of Science, Scopus, and Cochrane Library (last search: 1 March 2024). We included studies considering the treatment of vascular stenotic/occlusive or aneurysmal diseases. We included papers that reported the outcome of applications of 3D-printed models, excluding case reports or very limited case series (≤5 printed models or tests/simulations). Finally, 22 studies were included and analyzed. Computed tomography angiography (CTA) was the primary diagnostic method used to obtain the images serving as the basis for generating the 3D-printed models. Processing the CTA data involved the use of medical imaging software; 3DSlicer (Brigham and Women's Hospital, Harvard University, Boston, MA), ITK-Snap, and Mimics (Materialise NV, Leuven, Belgium) were the most frequently used. Autodesk Meshmixer (San Francisco, CA, USA) and 3-matic (Materialise NV, Leuven, Belgium) were the most frequently employed mesh-editing software during the post-processing phase. PolyJet™, fused deposition modeling (FDM), and stereolithography (SLA) were the most frequently employed 3D-printing technologies. Planning and training with 3D-printed models seem to enhance physicians' confidence and performance levels by up to 40% and lead to a reduction in the procedure time and contrast volume usage to varying extents.
    Keywords:  3D printing; endovascular surgery; planning; surgical education; surgical simulation; training; vascular surgery
    DOI:  https://doi.org/10.3390/diagnostics14151658
  6. ACS Appl Mater Interfaces. 2024 Aug 16.
      Bioactive metal-based nanostructures, particularly zinc oxide (ZnO), are promising materials for bone tissue engineering. However, integrating them into 3D-printed polymers using traditional blending methods reduces the cell performance. Alternative surface deposition techniques often require extreme conditions that are unsuitable for polymers. To address these issues, we propose a metal-assisted hydrothermal synthesis method to modify 3D printed polycaprolactone (PCL) scaffolds with ZnO nanoparticles (NPs), facilitating the growth of ZnO nanoarrays (NAs) at a low-temperature (55 °C). Physicochemical characterizations revealed that the ZnO NPs form both physical and chemical bonds with the PCL surface; chemical bonding occurs between the carboxylate groups of PCL and Zn(OH)2 during seed deposition and hydrothermal synthesis. The ZnO NPs and NAs grown for a longer time (18 h) on the surface of PCL scaffolds exhibit significant proliferation and early differentiation of osteoblast-like cells. The proposed method is suitable for the surface modification of thermally degradable polymers, opening up new possibilities for the deposition of diverse metals.
    Keywords:  3D bioprinting; ZnO nanostructures; bone regeneration; decorated scaffolds; hydrothermal synthesis
    DOI:  https://doi.org/10.1021/acsami.4c02644
  7. J Forensic Leg Med. 2024 Jul 25. pii: S1752-928X(24)00081-7. [Epub ahead of print]106 102719
      INTRODUCTION: The scientific community highlighted the relevance of 3D physical models since the beginning of the XXI century, complementary to three-dimensional(3D) digital volume by computer tomography, to support court discussions on medico-legal issues. The recreation of 3D evidence can be an important tool for investigators and experts, providing a better understanding of the causes and circumstances of the events involved in a crime.OBJECTIVE: The present study aims to assess the reproducibility of 3D printed and 3D tomographic volumes generated from mandibles following simulated forensic injuries, highlighting the recreation of crime tools.
    MATERIAL AND METHODS: Concerning the study design presented, data collection was performed in three phases. Nine simulated injuries of forensic interest were selected (phase1) and all the mandibles were scanned tomographically, individually, by Cone Beam Computed Tomography CBCT (phase 2). Then, in phase 3, the DICOM images were used for 3D printing with the Ender 3® printer by the Fused Deposition Modeling (FDM) technique. The data analysis followed two procedures: the comparison between the artificial mandible and 3D tomographic volume (AT) and the comparison between the artificial mandible and 3D printed volume, or the copy (AC). Data were analyzed using T-Student and ICC tests and presented in Bland-Altman plots.
    CONCLUSION: The analogic technique applied in 3D printed volume, when compared with computerized technique, using 3D digital images and measurement, showed to be accurate and reproducible. Further studies are needed in search of standardization for three-dimensional measurements in digitized and printed volumes.
    Keywords:  Cone beam computed tomography; Forensic ballistics; Forensic science; Radiologic technology; Three-dimensional printing
    DOI:  https://doi.org/10.1016/j.jflm.2024.102719