{"title":"4D fabrication of shape-changing systems for tissue engineering: state of the art and perspectives.","authors":"Lorenzo Bonetti, Giulia Scalet","doi":"10.1007/s40964-024-00743-5","DOIUrl":"10.1007/s40964-024-00743-5","url":null,"abstract":"<p><p>In recent years, four-dimensional (4D) fabrication has emerged as a powerful technology capable of revolutionizing the field of tissue engineering. This technology represents a shift in perspective from traditional tissue engineering approaches, which generally rely on static-or passive-structures (e.g., scaffolds, constructs) unable of adapting to changes in biological environments. In contrast, 4D fabrication offers the unprecedented possibility of fabricating complex designs with spatiotemporal control over structure and function in response to environment stimuli, thus mimicking biological processes. In this review, an overview of the state of the art of 4D fabrication technology for the obtainment of cellularized constructs is presented, with a focus on shape-changing soft materials. First, the approaches to obtain cellularized constructs are introduced, also describing conventional and non-conventional fabrication techniques with their relative advantages and limitations. Next, the main families of shape-changing soft materials, namely shape-memory polymers and shape-memory hydrogels are discussed and their use in 4D fabrication in the field of tissue engineering is described. Ultimately, current challenges and proposed solutions are outlined, and valuable insights into future research directions of 4D fabrication for tissue engineering are provided to disclose its full potential.</p>","PeriodicalId":36643,"journal":{"name":"Progress in Additive Manufacturing","volume":"10 4","pages":"1913-1943"},"PeriodicalIF":4.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11926060/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143693766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vladislav Yakubov, Halsey Ostergaard, Shishira Bhagavath, Chu Lun Alex Leung, James Hughes, Evren Yasa, Mani Khezri, Sandra K Löschke, Qing Li, Anna M Paradowska
{"title":"Multimodal defect analysis and application of virtual machining for solid-state manufactured aluminium structure.","authors":"Vladislav Yakubov, Halsey Ostergaard, Shishira Bhagavath, Chu Lun Alex Leung, James Hughes, Evren Yasa, Mani Khezri, Sandra K Löschke, Qing Li, Anna M Paradowska","doi":"10.1007/s40964-024-00904-6","DOIUrl":"10.1007/s40964-024-00904-6","url":null,"abstract":"<p><p>Additive friction stir deposition (AFSD) is an emerging solid-state non-fusion additive manufacturing (AM) technology, which produces parts with wrought-like material properties, high deposition rates, and low residual stresses. However, impact of process interruption on defect formation and mechanical properties has not yet been well addressed in the literature. In this study, Al6061 aluminium structure with two final heights and deposition interruption is successfully manufactured via AFSD and characterised. Defect analysis conducted via optical microscopy, electron microscopy, and X-ray computed tomography reveals > 99% relative density with minimal defects in centre of the parts. However, tunnel defects at interface between substrate and deposit as well as kissing bonds are present. Edge of deposit contains tunnel defects due to preference for greater material deposition on advancing side of rotating tool. Virtual machining highlights the ability to remove defects via post-processing, avoiding mechanical performance impact of stress concentrating pores. Electron backscatter diffraction revealed regions with localised shear bands that contain 1-5 µm equivalent circular diameter grains. Kissing bonds are exhibited in areas separated by large grain size difference. Meanwhile, Vickers hardness testing reveals hardness variation with deposit height. This work advances the understanding of complex microstructure development, material flow, and mechanical behaviour of AFSD Al6061 alloy.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s40964-024-00904-6.</p>","PeriodicalId":36643,"journal":{"name":"Progress in Additive Manufacturing","volume":"10 8","pages":"5281-5297"},"PeriodicalIF":4.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12267324/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144676044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The effect of inter- and intra-layer delay time on TPU parts fabricated by laser powder bed fusion.","authors":"Samuel Connor, Ruth Goodridge, Ian Maskery","doi":"10.1007/s40964-024-00933-1","DOIUrl":"10.1007/s40964-024-00933-1","url":null,"abstract":"<p><p>In polymer laser powder bed fusion (PBF-LB-P) techniques, such as laser sintering, the time between scanning a given point in one layer and the same <i>x-y</i> point in the next layer is known as the 'inter-layer delay time'. Multiple parts are normally fabricated in a PBF-LB-P build for efficiency; however, this leads to variation in the inter-layer delay time for individual parts; in this study, we present a specific investigation using a commercially available thermoplastic polyurethane (TPU). Multiple part layouts were used and the resulting parts were subject to tensile testing and fracture surface analysis. The results demonstrate that an increase in inter-layer delay time can lead to a significant reduction in mechanical properties. Fabricating specimens in groups of 5 led to a 10% reduction in ultimate tensile strength, 30% reduction in extension at break, and 15 <math><mo>%</mo></math> reduction in Young's modulus compared to specimens fabricated individually. Fractography suggests this is due to decreased inter-layer bonding and an increase in defects. This has significant implications for the production of multiple parts in a build where consistent mechanical properties are critical. Based on our understanding of this detrimental effect, we put forward a novel build packing approach for PBF-LB-P, based on scanning area equivalence rather than the conventional time minimisation, to mitigate against it.</p>","PeriodicalId":36643,"journal":{"name":"Progress in Additive Manufacturing","volume":"10 8","pages":"5661-5674"},"PeriodicalIF":4.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12267361/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144676045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marina Kühn-Kauffeldt, Marvin Kühn, Christoph Mittermeier, Josef Kiendl
{"title":"Fused filament fabrication of polyetheretherketone in vacuum: the influence of high vacuum on layer adhesion in z-orientation.","authors":"Marina Kühn-Kauffeldt, Marvin Kühn, Christoph Mittermeier, Josef Kiendl","doi":"10.1007/s40964-024-00897-2","DOIUrl":"10.1007/s40964-024-00897-2","url":null,"abstract":"<p><p>The application of fused filament fabrication (FFF) in vacuum changes the heat transfer of the process. This work investigates the influence of the working ambient pressure conditions in FFF-based 3D printing of polyetheretherketone (PEEK) specimens, and its impact on the resulting part strength. Layer adhesion drastically improves with decreasing pressure, maximum layer adhesion is reached for ambient pressure below <math><msup><mn>10</mn> <mrow><mo>-</mo> <mn>3</mn></mrow> </msup> </math> mbar. We show that simple and low-cost vacuum equipment is sufficient to achieve such pressure conditions, making this process interesting for the general processing of high-temperature polymers using FFF.</p>","PeriodicalId":36643,"journal":{"name":"Progress in Additive Manufacturing","volume":"10 8","pages":"5205-5215"},"PeriodicalIF":4.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12267327/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144676043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yunjie Hao, Chuanyung Wu, Yuchuan Su, Jude Curran, James R Henstock, Fangang Tseng
{"title":"A 4D printed self-assembling PEGDA microscaffold fabricated by digital light processing for arthroscopic articular cartilage tissue engineering.","authors":"Yunjie Hao, Chuanyung Wu, Yuchuan Su, Jude Curran, James R Henstock, Fangang Tseng","doi":"10.1007/s40964-022-00360-0","DOIUrl":"10.1007/s40964-022-00360-0","url":null,"abstract":"<p><p>Articular cartilage in synovial joints such as the knee has limited capability to regenerate independently, and most clinical options for focal cartilage repair merely delay total joint replacement. Tissue engineering presents a repair strategy in which an injectable cell-laden scaffold material is used to reconstruct the joint in situ through mechanical stabilisation and cell-mediated regeneration. In this study, we designed and 3D-printed millimetre-scale micro-patterned PEGDA biomaterial microscaffolds which self-assemble through tessellation at a scale relevant for applications in osteochondral cartilage reconstruction. Using simulated chondral lesions in an in vitro model, a series of scaffold designs and viscous delivery solutions were assessed. Hexagonal microscaffolds (750 μm x 300 μm) demonstrated the best coverage of a model cartilage lesion (at 73.3%) when injected with a 1% methyl cellulose solution. When chondrocytes were introduced to the biomaterial via a collagen hydrogel, they successfully engrafted with the printed microscaffolds and survived for at least 14 days in vitro, showing the feasibility of reconstructing stratified cartilaginous tissue using this strategy. Our study demonstrates a promising application of this 4D-printed injectable technique for future clinical applications in osteochondral tissue engineering.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s40964-022-00360-0.</p>","PeriodicalId":36643,"journal":{"name":"Progress in Additive Manufacturing","volume":"9 1","pages":"3-14"},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10851926/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139708103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Impact of printing parameters on in-plane tensile and fracture toughness of fused filament fabricated PEEK","authors":"M. Refat, E. Zappino, A. Pagani","doi":"10.1007/s40964-023-00554-0","DOIUrl":"https://doi.org/10.1007/s40964-023-00554-0","url":null,"abstract":"","PeriodicalId":36643,"journal":{"name":"Progress in Additive Manufacturing","volume":"50 s176","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139145994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Adrianna Staszewska, Deepali P. Patil, Akshatha C. Dixith, R. Neamtu, D. Lados
{"title":"A machine learning methodology for porosity classification and process map prediction in laser powder bed fusion","authors":"Adrianna Staszewska, Deepali P. Patil, Akshatha C. Dixith, R. Neamtu, D. Lados","doi":"10.1007/s40964-023-00544-2","DOIUrl":"https://doi.org/10.1007/s40964-023-00544-2","url":null,"abstract":"","PeriodicalId":36643,"journal":{"name":"Progress in Additive Manufacturing","volume":"76 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139161254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Cortis, Daniela Pilone, G. Broggiato, F. Campana, Danilo Tatananni, D. Orlandi
{"title":"Setting of L-PBF parameters for obtaining high density and mechanical performance of AISI 316L and 16MnCr5 alloys with fine laser spot size","authors":"D. Cortis, Daniela Pilone, G. Broggiato, F. Campana, Danilo Tatananni, D. Orlandi","doi":"10.1007/s40964-023-00556-y","DOIUrl":"https://doi.org/10.1007/s40964-023-00556-y","url":null,"abstract":"","PeriodicalId":36643,"journal":{"name":"Progress in Additive Manufacturing","volume":"8 15","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138944271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"4D printing of shape memory polymer with continuous carbon fiber","authors":"S. S. Kumar, J. Akmal, Mika Salmi","doi":"10.1007/s40964-023-00553-1","DOIUrl":"https://doi.org/10.1007/s40964-023-00553-1","url":null,"abstract":"","PeriodicalId":36643,"journal":{"name":"Progress in Additive Manufacturing","volume":" 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138961846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pedro Rendas, Lígia Figueiredo, Ricardo Cláudio, Catarina Vidal, Bruno A. R. Soares
{"title":"Investigating the effects of printing temperatures and deposition on the compressive properties and density of 3D printed polyetheretherketone","authors":"Pedro Rendas, Lígia Figueiredo, Ricardo Cláudio, Catarina Vidal, Bruno A. R. Soares","doi":"10.1007/s40964-023-00550-4","DOIUrl":"https://doi.org/10.1007/s40964-023-00550-4","url":null,"abstract":"","PeriodicalId":36643,"journal":{"name":"Progress in Additive Manufacturing","volume":"3 s4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138967901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}