Biofabrication最新文献

Overcoming the low cell survival rates and insufficient neovascularization associated with tissue engineering of the vagina is crucial for advancing the vaginal reconstruction. In this research, we have developed a unique bioink composed of porcine vaginal extracellular matrix (vECM), gelatin methacrylamide (GelMA), and silk fibroin (SF) to facilitate the bioprinting of a vaginal scaffold. The vECM-GelMA-SF bioink effectively replicates thein vivomicroenvironment, supporting thein vitrocultivation of 3D bioprinted vaginal scaffolds. It promotes stem cell viability and enhances neovascularization by harnessing the mechanical properties of GelMA/SF and the tissue specificity of vECM.In vivoorthotopic studies have demonstrated that the use of 3D bioprinted vaginal scaffolds significantly improves the functionality of reconstructed vaginas, promoting angiogenesis, rapid epithelialization, muscle regeneration, glycogen secretion, and nerve repair. The reconstructed vaginal tissues in the 3D cell-loaded scaffold group closely resemble natural vaginal tissues. Differential proteomics analysis has provided insights into the genetic functions and biological pathways involved in vaginal reconstruction. Our study successfully optimized the composition of the vECM-GelMA-SF bioink, achieving a balance between biocompatibility and printability. This bioink is suitable for constructing 3D bioprinted vaginal scaffolds of various dimensions, transplantablein situin animal models with different degrees of vaginal absence. The bioink may find applications in clinical settings, improving the overall effectiveness and safety ofin vivovaginal reconstruction procedures.

Acoustic bioassembly is recently regarded as a highly efficient biofabrication tool to generate functional tissue mimics. Despite their capacity of directly patterning live cells with close intercellular proximity, most acoustic bioassembly techniques are currently limited to generate some specific simple types of periodic and symmetric patterns, which represents an urgent challenge to emulate geometrically complex cytoarchitecture in human tissue. To address this challenge, we herein demonstrate a soft-lithographically defined acoustic bioassembly (SLAB) technique that enables to assemble live cells into geometrically defined arbitrary multicellular structures. Particularly, we employed a widely accessible soft lithography technique to fabricate a polydimethylsiloxane (PDMS) construct that works as an amplitude modulation template to define the pressure distribution of near-field acoustic waves. We found that zero pressure areas of the near-field acoustic waves at the PDMS surface distribute above the air-filling regions of the PDMS construct when both the PDMS top layer and air layer are approximately one-tenth of the acoustic wavelength. Using this technique, bioparticles can be assembled into symmetrical or asymmetrical patterns. Specifically, we have demonstrated the SLAB of endothelial spheroids and hepatic cells into liver tissue mimics (LTMs). The functional analysis further indicates that the formed LTMs displayed liver-specific functions, including albumin secretion, urea synthesis, glucose metabolism, and lipid storage. We expect this SLAB technique will be broadly used to construct complex functional tissues for tissue engineering and regenerative medicine.

The specific spatiotemporal distribution of diverse components in tumor microenvironment plays a crucial role in the cancer progression.In vitrothree-dimensional (3D) tumor models with polydimethylsiloxane (PDMS) based microfluidic platform have been applied as useful tool to conduct studies from cancer biology to drug screening. However, PDMS has not been welcomed as a standardized commercial application for preclinical screening due to inherent limitations in scale-up production and molecule absorption. Here, we present a novel microfluidic platform to flexibly construct 3D co-culture models with spatiotemporal resolution by using multiple digital manufacturing technologies. The platform, which consist of reduplicative microfluidic chips, is made of biocompatible poly methyl methacrylate by fast laser cutting. Each replica includes a simple microfluidic chamber without internal structures which can be flexibly post-fabricated according to various research requirements. Digital light processing based 3D bioprinting was used to pattern fine hydrogel structures for post-fabrication on-chip. By multi-step bioprinting and automatic image alignment, we show that this approach provides sufficient design flexibility to construct 3D co-culture tumor model with spatiotemporal resolution to replicate microarchitecture of tumor microtissuein situ. And the tumor model has the potential to mimic tumor biology behaviors which can be used for mechanism study and drug test. Our microengineered tumor model may serve as an enabling tool to recapitulate pathophysiological complexity of tumor, and to systematically examine the contribution of the tumor microenvironment to the cancer progression. The proposed strategy can also be applied to help engineer diverse meaningfulin vitromodels for extensive biomedical applications, from physiology and disease study to therapy evaluation.

Bioprinting a resilient yet optically transparent corneal tissue substitute remains a challenge. In this study we introduce an innovative methodology aimed at bolstering the mechanical and optical attributes of silk fibroin (SF) hydrogels, pivotal for the progression of cornea tissue engineering. We devised a unique eosin Y-based photoinitiator system to instigate di-tyrosine linkages within highly concentrated pristine SF solutions under green light exposure. This pioneering technique resulted in SF hydrogels fortified by dityrosine covalent bonds, preserving exceptional transparency and soft elastomeric qualities devoid of spontaneous transitions to stiff, opaque beta-sheet conformations. Furthermore, we synergistically combined SF with decellularized cornea matrix (DCM) hydrogel, leveraging photo-polymerization under green light followed by thermal gelation to establish resilient and stable gel formation. The ensuing dual crosslinked hybrid hydrogels exhibited superior mechanical and thermal resilience in comparison to dual crosslinked DCM hydrogels. The inclusion of SF in DCM further augmented the hydrogel's elasticity and shear recovery, positioning it as an optimal bioink for cornea bioprinting endeavors. During the extrusion printing process, photocrosslinking of the bioink superficially fortified SF and DCM polymer chains via di-tyrosine linkages, furnishing initial stability and mechanical fortitude. Subsequent post-printing thermal gelation further reinforced collagen chains through self-assembly. Notably, the bioprinted cornea constructs, housing human limbal mesenchymal stem cells, manifested transparency, structural integrity, and optimal functionality, underscored by the expression of keratocyte proteoglycans. In summation, our engineered 3D constructs exhibit promising potential forin vivoapplications in cornea tissue engineering, marking a significant stride forward in the field's advancement.

Recombinant collagen holds immense potential in the development of medical functional materials, yet its widespread application remains hindered by the absence of a suitable self-assembly strategy. In this article, we report the discovery that the bacterial-derived collagen-like (CL) protein Scl2 can rapidly self-gelation (∼1 min at pH ∼7) due to properties enabled by metal coordination crosslinking. This was achieved by fusing metal ion chelating peptides to both termini of the protein. Our research further reveals the critical role of electrostatic interaction between globular domains (V domains) of recombinant collagen in the self-assembly process. We show that modifying the negative charge load of the N-terminalα-helix of the V domain enables control over the self-assembly time (from 1 min to 30 min) and strength (from 8 kPa to 26 kPa) of the Scl2 hydrogel. By adjusting the molecular weight of the core CL domain, we have remarkably further enhanced the strength of the Scl2 hydrogel to 78 kPa. Moreover, we innovatively employed electro-oxidized tea polyphenols to enhance the stability of the Scl2 hydrogel, resulting in the formation of a reliable self-assembled metal coordination hydrogel at physiological temperature. This approach not only eliminates the need for toxic chemical crosslinking agents but also confers the material with multiple functionalities, such as adhesion, antibacterial, and antioxidant properties. The novel recombinant Scl2 hydrogel exhibited exceptionalin situself-gelation and injectable properties. This innovative hydrogel not only demonstrates remarkable biological activity but also exhibits remarkable tissue repair-promoting capabilities in full-thickness skin injury models (shorten healing cycle by more than 30%). The convenient and versatile nature of this recombinant collagen hydrogel makes it promising for clinical applications in injury treatment, demonstrating broad applications in the future.

In modern agriculture, nanotechnology was recognized as a potentially transformative innovation. Nanopolymers as coating matrix in nano-biofertilizer has a massive impact on agricultural productivity. The integration of nanotechnology with biofertilizers has led to the creation of nano-biofertilizer formulations that enhance nutrient delivery, improve plant growth, and increase resistance to environmental stress. Nanopolymers, both synthetic and biogenic, including chitosan, cellulose, gelatin, sodium alginate, starch, and polyvinyl alcohol, are utilized as encapsulating materials. They are effective in ensuring controlled nutrient release and shielding beneficial microorganisms from external environmental conditions. Studies indicate that nano-biofertilizers improve soil quality, raise crop yields, and reduce the usage of chemical fertilizers to enhance sustainable agricultural practices. The review also addresses the microbial encapsulation methodology, release kinetics, phytotoxicity, challenges and future prospects of nano-biofertilizer technology, including nanoparticle-bacteria interaction, scalability, and regulatory considerations. This paper elaborates the potential and limitations of nano-biofertilizers, providing insights for future advancements in the agriculture field.

Kidney diseases are among the leading causes of death globally. With the increasing rates of acute kidney injury (AKI) requiring hospitalisation, a better understanding of pathophysiological mechanisms is needed to treat the patients more efficiently. Nephrotoxicity is one of the most common causes of AKI, mainly due to the high availability of over-the-counter drugs and natural supplements, which may interact with prescribed drugs at the level of pharmacokinetics, among other factors. The latter can lead to clinically relevant complications (including AKI), which is even more pronounced given the increasingly ageing population in the Western world and the associated increase in polypharmacy. Drug testing starts at the preclinical level, where a reliable model is needed to predict human response to a tested drug with sufficient accuracy. Recently,in-vitrokidney models of different complexities have been created to study various aspects of kidney diseases. Because the proximal tubule plays a vital role in several mechanisms, many models include proximal tubular epithelial cells (PTECs). Monocultures of PTECs do not representin-vivotissue accurately enough. Therefore, more complex models with more cell types are being built. To our knowledge, this is the first review focusing on co-culture models and cell types used alongside PTECs for studying the nephrotoxicity of drugs and other mechanisms of AKI and chronic kidney disease.

The recent occurrence of the Covid-19 pandemic and frequent wildfires have worsened pulmonary diseases and raised the urgent need for investigating host-pathogen interactions and advancing drug and vaccine therapies. Historically, research and experimental studies have relied on two-dimensional cell culture dishes and/or animal models, which suffer from physiological differences from the human lung. More recently, there has been investigation into the use of lung-on-a-chip models and organoids, while the use of bioprinting technologies has also emerged to fabricate three-dimensional constructs or lung models with enhanced physiological relevance. Concurrently, achievements have also been made to develop biomimetic strategies for simulating thein vivobiomechanical conditions induced by lung breathing, though challenges remain with incorporating these strategies with bioprinted models. Bioprinted models combined with advanced biomimetic strategies would represent a promising approach to advance disease discovery and therapeutic development. As inspired, this article briefly reviews the recent progress of both bioprintedin vitrolung models and biomechanical strategies, with a focus on native lung tissue microstructure and biomechanical properties, bioprinted constructs, and biomimetic strategies to mimic the native environment. This article also urges that the integration of bioprinting advances and biomimetic strategies would be essential to achieve synergistic effects forin vitrolung modelling. Key issues and challenges are also identified and discussed along with recommendations for future research.

Artificial bone graft stands out for avoiding limited source of autograft as well as susceptibility to infection of allograft, which makes it a current research hotspot in the field of bone defect repair. However, traditional design and manufacturing method cannot fabricate bone scaffold that well mimics complicated bone-like shape with interconnected porous structure and multiple properties akin to human natural bone. Additive manufacturing, which can achieve implant's tailored external contour and controllable fabrication of internal microporous structure, is able to form almost any shape of designed bone scaffold via layer-by-layer process. As additive manufacturing is promising in building artificial bone scaffold, only combining excellent structural design with appropriate additive manufacturing process can produce bone scaffold with ideal biological and mechanical properties. In this article, we sum up and analyze state of art design and additive manufacturing methods for bone scaffold to realize shape/properties collaborative intelligent manufacturing. Scaffold design can be mainly classified into design based on unit cells and whole structure, while basic additive manufacturing and 3D bioprinting are the recommended suitable additive manufacturing methods for bone scaffold fabrication. The challenges and future perspectives in additive manufactured bone scaffold are also discussed.

In this present study, we introduce an innovative hybrid 3D bioprinting methodology that integrates fused deposition modeling (FDM) with top-down digital light processing (DLP) for the fabrication of an artificial trachea. Initially, polycaprolactone (PCL) was incorporated using an FDM 3D printer to provide essential mechanical support, replicating the structure of tracheal cartilage. Subsequently, a chondrocyte-laden glycidyl methacrylated silk fibroin hydrogel was introduced via top-down DLP into the PCL scaffold (PCL-Sil scaffold). The mechanical evaluation of PCL-Sil scaffolds showed that they have greater flexibility than PCL scaffolds, with a higher deformation rate (PCL-Sil scaffolds: 140.9% ± 5.37% vs. PCL scaffolds: 124.3% ± 6.25%) and ability to withstand more force before fracturing (3.860 ± 0.140 N for PCL-Sil scaffolds vs. 2.502 ± 0.126 N for PCL scaffolds, ***P< 0.001). Both types of scaffolds showed similar axial compressive strengths (PCL-Sil scaffolds: 4.276 ± 0.127 MPa vs. PCL scaffolds: 4.291 ± 0.135 MPa). Additionally, PCL-Sil scaffolds supported fibroblast proliferation, indicating good biocompatibility.In vivotesting of PCL-Sil scaffolds in a partial tracheal defect rabbit model demonstrated effective tissue regeneration. The scaffolds were pre-cultured in the omentum for two weeks to promote vascularization before transplantation. Eight weeks after transplantation into the animal, bronchoscopy and histological analysis confirmed that the omentum-cultured PCL-Sil scaffolds facilitated rapid tissue regeneration and maintained the luminal diameter at the anastomosis site without signs of stenosis or inflammation. Validation study to assess the feasibility of our hybrid 3D bioprinting technique showed that structures, not only the trachea but also the vertebral bone-disc and trachea-lung complex, were successfully printed.