3D-printed high-density polyethylene scaffolds with bioactive and antibacterial layer-by-layer modification for auricle reconstruction

[Research progress of three-dimensional bioprinting technology in auricle repair and reconstruction]

Objective

To review the research progress on the application of three-dimensional (3D) bioprinting technology in auricle repair and reconstruction.

Methods

The recent domestic and international research literature on 3D printing and auricle repair and reconstruction was extensively reviewed, and the concept of 3D bioprinting technology and research progress in auricle repair and reconstruction were summarized.

Results

The auricle possesses intricate anatomical structure and functionality, necessitating precise tissue reconstruction and morphological replication. Hence, 3D printing technology holds immense potential in auricle reconstruction. In contrast to conventional 3D printing technology, 3D bioprinting technology not only enables the simulation of auricular outer shape but also facilitates the precise distribution of cells within the scaffold during fabrication by incorporating cells into bioink. This approach mimics the composition and structure of natural tissues, thereby favoring the construction of biologically active auricular tissues and enhancing tissue repair outcomes.

Conclusion

3D bioprinting technology enables the reconstruction of auricular tissues, avoiding potential complications associated with traditional autologous cartilage grafting. The primary challenge in current research lies in identifying bioinks that meet both the mechanical requirements of complex tissues and biological criteria.

The H2O2 Self-Sufficient 3D Printed β-TCP Scaffolds with Synergistic Anti-Tumor Effect and Reinforced Osseointegration

Tumor recurrence and massive bone defects are two critical challenges for postoperative treatment of oral and maxillofacial tumor, posing serious threats to the health of patients. Herein, in order to eliminate residual tumor cells and promote osteogenesis simultaneously, the hydrogen peroxide (H2O2) self-sufficient TCP-PDA-CaO2-CeO2 (TPCC) scaffolds are designed by preparing CaO2 or/and CeO2 nanoparticles (NPs)/chitosan solution and modifying the NPs into polydopamine (PDA)-modified 3D printed TCP scaffolds by rotary coating method. CaO2 NPs loaded on the scaffolds can release Ca2+ and sufficient H2O2 in the acidic tumor microenvironment (TME). The generated H2O2 can further produce hydroxyl radicals (·OH) under catalysis effect by peroxidase (POD) activity of CeO2 NPs, in which the photothermal effect of the PDA coating enhances its POD catalytic effect. Overall, NPs loaded on the scaffold chemically achieve a cascade reaction of H2O2 self-sufficiency and ·OH production, while functionally achieving synergistic effects on anti-tumor and bone promotion. In vitro and in vivo studies show that the scaffolds exhibit effective osteo-inductivity, induced osteoblast differentiation and promote osseointegration. Therefore, the multifunctional composite scaffolds not only validate the concept of chemo-dynamic therapy (CDT) cascade therapy, but also provide a promising clinical strategy for postoperative treatment of oral and maxillofacial tumor.

Recent Development and Applications of Polydopamine in Tissue Repair and Regeneration Biomaterials

The various tissue damages are a severe problem to human health. The limited human tissue regenerate ability requires suitable biomaterials to help damage tissue repair and regeneration. Therefore, many researchers devoted themselves to exploring biomaterials suitable for tissue repair and regeneration. Polydopamine (PDA) as a natural and multifunctional material which is inspired by mussel has been widely applied in different biomaterials. The excellent properties of PDA, such as strong adhesion, photothermal and high drug-loaded capacity, seem to be born for tissue repair and regeneration. Furthermore, PDA combined with different materials can exert unexpected effects. Thus, to inspire researchers, this review summarizes the recent and representative development of PDA biomaterials in tissue repair and regeneration. This article focuses on why apply PDA in these biomaterials and what PDA can do in different tissue injuries.

Engineering Cardiac Tissue for Advanced Heart-On-A-Chip Platforms

Cardiovascular disease is a major cause of mortality worldwide, and current preclinical models including traditional animal models and 2D cell culture models have limitations in replicating human native heart physiology and response to drugs. Heart-on-a-chip (HoC) technology offers a promising solution by combining the advantages of cardiac tissue engineering and microfluidics to create in vitro 3D cardiac models, which can mimic key aspects of human microphysiological systems and provide controllable microenvironments. Herein, recent advances in HoC technologies are introduced, including engineered cardiac microtissue construction in vitro, microfluidic chip fabrication, microenvironmental stimulation, and real-time feedback systems. The development of cardiac tissue engineering methods is focused for 3D microtissue preparation, advanced strategies for HoC fabrication, and current applications of these platforms. Major challenges in HoC fabrication are discussed and the perspective on the potential for these platforms is provided to advance research and clinical applications.

3D Printing Applications for Craniomaxillofacial Reconstruction: A Sweeping Review

The field of craniomaxillofacial (CMF) surgery is rich in pathological diversity and broad in the ages that it treats. Moreover, the CMF skeleton is a complex confluence of sensory organs and hard and soft tissue with load-bearing demands that can change within millimeters. Computer-aided design (CAD) and additive manufacturing (AM) create extraordinary opportunities to repair the infinite array of craniomaxillofacial defects that exist because of the aforementioned circumstances. 3D printed scaffolds have the potential to serve as a comparable if not superior alternative to the "gold standard" autologous graft. In vitro and in vivo studies continue to investigate the optimal 3D printed scaffold design and composition to foster bone regeneration that is suited to the unique biological and mechanical environment of each CMF defect. Furthermore, 3D printed fixation devices serve as a patient-specific alternative to those that are available off-the-shelf with an opportunity to reduce operative time and optimize fit. Similar benefits have been found to apply to 3D printed anatomical models and surgical guides for preoperative or intraoperative use. Creation and implementation of these devices requires extensive preclinical and clinical research, novel manufacturing capabilities, and strict regulatory oversight. Researchers, manufacturers, CMF surgeons, and the United States Food and Drug Administration (FDA) are working in tandem to further the development of such technology within their respective domains, all with a mutual goal to deliver safe, effective, cost-efficient, and patient-specific CMF care. This manuscript reviews FDA regulatory status, 3D printing techniques, biomaterials, and sterilization procedures suitable for 3D printed devices of the craniomaxillofacial skeleton. It also seeks to discuss recent clinical applications, economic feasibility, and future directions of this novel technology. By reviewing the current state of 3D printing in CMF surgery, we hope to gain a better understanding of its impact and in turn identify opportunities to further the development of patient-specific surgical care.

Polymer Multi-Block and Multi-Block+ Strategies for the Upcycling of Mixed Polyolefins and Other Plastics

Due to a continued rise in the production and use of plastic products, their end-of-life pollution has become a pressing global issue. One of the biggest challenges in plastics recycling is the separation of different polymers. Multi-block copolymers (MBCPs) represent an efficient strategy for the upcycling of mixed plastics via induced compatibilization, but this approach is limited by difficulties associated with synthesis and structural modification. In this contribution, several synthetic strategies are explored to prepare MBCPs with tunable microstructures, which were then used as compatibilizer additives to upcycle mixtures of polyolefins with other plastics. A multi-block+ strategy based on a reactive telechelic block copolymer platform was introduced, which enabled block extension during the in situ melt blending of mixed plastics, leading to better compatibilizing properties as well as better 3D printing capability. This strategy was also applicable to more complex ternary plastic blends. The polymer multi-block strategy enabled by versatile MBCPs synthesis and the multi-block+ strategy enabled by in situ block extension show exciting opportunities for the upcycling of mixed plastics.

Photosynthetic Living Fiber Fabrication from Algal-Bacterial Consortia with Controlled Spatial Distribution

Living materials that combine living cells and synthetic matrix materials have become promising research fields in recent years. While multicellular systems present exclusive benefits in developing living materials over single-cell systems, creating artificial multicellular systems can be challenging due to the difficulty in controlling the multicellular assemblies and the complexity of cell-to-cell interactions. Here, we propose a coculture platform capable of isolating and controlling the spatial distribution of algal-bacterial consortia, which can be utilized to construct photosynthetic living fibers. Through coaxial extrusion-based 3D printing, hydrogel fibers containing bacteria or algae can be deposited into designated structures and further processed into materials with precise geometries. In addition, the photosynthetic living fibers demonstrate a significant synergistic catalytic effect resulting from the immobilization of both bacteria and algae, which effectively optimizes sewage treatment for bioremediation purposes. The integration of microbial consortia and 3D printing yields functional living materials with promising applications in biocatalysis, biosensing, and biomedicine. Our approach provides an optimized solution for constructing efficient multicellular systems and opens a new avenue for the development of advanced materials.

Multiscale Anisotropic Scaffold Integrating 3D Printing and Electrospinning Techniques as a Heart-on-a-Chip Platform for Evaluating Drug-Induced Cardiotoxicity

Cardiac safety assessments are significant in drug discovery, as drug-induced cardiotoxicity (DIC) is the primary cause of drug attrition. Despite heart-on-a-chip (HoC) technology becoming an increasingly popular tool for evaluating DIC, its development remains a challenge owing to the anisotropic cardiac structure of the native myocardium. Herein, an anisotropic multiscale cardiac scaffold is presented via a hybrid biofabrication method by combining 3D printing with electrospinning technology, where the 3D-printed micrometer-scale scaffold frames enable mimicking the interwoven myocardium anatomical structure and the branched-aligned electrospun nanofibers network is able to directionally guide cellular arrangements. The in vitro 3D bioengineered cardiac tissues are then fabricated by encapsulating three-layer multiscale scaffolds within a photocurable methacrylated gelatin hydrogel shell. It is demonstrated that such an anisotropic multiscale structure could contribute to enhancing cardiomyocyte maturation and synchronous beating behavior. More attractively, with the integration of 3D bioengineered cardiac tissues and a self-designed microfluidic perfusion system, a 3D anisotropic HoC platform is established for evaluating DIC and cardioprotective efficacy. Collectively, these results indicate that the HoC model developed by integrating the 3D bioengineered cardiac tissues could effectively recapitulate the clinical manifestations, thereby highlighting their efficacy as a valuable preclinical platform for testing drug efficacy and cardiotoxicity.

How 3D scaffolds with different mechanical properties affect the activity of neuronal networks in in vitro models. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023;2023:1-4. [PMID: 38083594 DOI: 10.1109/embc40787.2023.10340624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Three-dimensionality has been proven extensively to be critical in the development of a reliable model for different anatomical compartments and for many diseases. Currently, we can produce implantable structures that help in the regeneration of different tissues such as bone and heart. Different is the situation when we consider the neuronal compartment. As it is still difficult to understand exactly how the brain computes, to conceive how the complex chain of neuronal events can generate conscious behavior, a comprehensive and workable model of neuronal tissue still has to be found. In this perspective, in the present work, we developed and compared different 3D scaffolds to understand the effects produced by the mechanical and material properties of four different scaffolds on a 3D neuronal network. To help in preclinical testing procedure, the scalability and ease-of-use of the different approaches were also taken into consideration.Clinical Relevance- By comparing different 3D scaffolds for the creation of neuronal constructs, the results in this paper move towards understanding the best strategy to develop functional 3D neuronal units for reliable pre-clinical studies.