Bioprinting最新文献

Polylactic acid (PLA)/Magnesium (Mg)-based composites exhibit great potential for applications in bone regeneration and tissue engineering. PLA is a biodegradable and biocompatible polymer, that has the ability to be easily shaped into diverse structures like scaffolds, films, and fibers. However, its inherent low biodegradability limits its applicability for tissue engineering. On the other hand, magnesium, a biocompatible metal known for its good biodegradability and osteoconductivity, is well-suited for bone tissue engineering. In this study, we fabricated and characterized a composite material of Mg/PLA with 5, 10, and 15 wt%Mg alloy (AZ61), which was subsequently 3D printed. The incorporation of Mg particles into PLA matrix offers a solution to overcome the low biodegradation limitations typically associated with the PLA. Moreover, it helps counteract the negative consequences related to the rapid degradation of Mg, such as alkalinization and excessive release of H₂. Additionally, the change in pH values and changes in mass during in vitro degradation indicated that the addition of Mg effectively counteracted the acidic byproducts generated by PLA. Furthermore, X-Ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR) spectroscopy were utilized to investigate the degradation of the scaffolds, while thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used to compare and contrast the thermal properties of the composites. Our findings demonstrate that the addition of Mg significantly influences the thermal properties of PLA and notably accelerates its degradation, in addition to its noticeable influence on cell adhesion.

3D printing first came into existence in the year 1984. Since then, it has found significant use in various fields, including pharmaceutical industries.3D printing is a process of manufacturing products by depositing materials layer by layer. Thus, also called additive manufacturing. Additive manufacturing provides patient-specific formulation, an advantage over conventional drug design methods. 3D printing helps in the designing of complex structures. Since the approval of the first 3D-printed tablet, this field has gained popularity. In this review, various techniques used in 3D printing have been discussed. This article further gives insight into the recent research done on AM technology. There is also some discussion about the formulations made for pediatric patients using AM technology. Different types of drug delivery systems mentioned in this work are oral, vaginal, rectal, oro-mucosal, transdermal, and implant. Further drug testing devices, including 3D-printed organoids and organ-on-chip models, have been discussed. Finally, it gives information about the future direction of this technology.

3D-bioprinting has become a valid technique for tissue and organ regeneration, as the printing of living cells is allowed while the hydrogel-based ink material provides them mechanical and structural support. Self-healing shear-thinning hydrogel inks can be considered most promising ink materials for extrusion-based bioprinting (EBB), because the ink can be extruded due to the decrease in viscosity under shear, and self-healed after removing the shear, which ensures safe printing of cells and shape fidelity after bioprinting. To achieve the best final bioprinting result, some printing technique, ink material and biological aspects of bioprinting need to be considered. In addition, the versatile characterization of pre- and post-printing properties of the inks helps to improve the final bioprinted constructs. However, despite the great advances in 3D-bioprinting, ink related challenges such as opposing characteristics, and lack of controllable micro-environment, or technological challenges such as the need to increase printing speed and print resolution must be resolved. In terms of ink characterization, more standardization is also needed. In addition, the computational modeling would help to improve the performance of the bioprinted construct. Thus, the future of 3D-bioprinting is going towards larger multifunctional tissue/organ constructs with multi-scale vascularization and innervation. Multiple printing techniques are probably combined, but also completely new techniques are needed. Further, multimaterial printing would enable heterogeneity and gradients to the construct. On the other hand, using 4D-bioprinting, the dynamic nature of complex organs could be added to the construct. By combining bioprinting with microphysiological platforms (tissue- or organ-on-a-chip systems) the development of functional tissues and organs intended for implantation would go forward. The translation of EBB into clinical practice is still in the early stages, but EBB has a great potential in regenerative medicine after the challenges, such as biomimicry, reproducibility or up-scaling related issues have been overcome. In this review, the design aspects related to extrusion-based bioprinting technique, the property requirements for ideal bioink, the biological aspects of 3D-bioprinting, and the characterization of the pre- and post-printing properties of bioinks are presented. Also, the challenges and future prospects of 3D-bioprinting are discussed.

In recent years, numerous strategies have emerged to answer the growing demand for graftable tissues. Tissue engineering and in-vitro production are one of them. Among all the engineered tissues, skin is one of the most advanced. Nevertheless, biofabrication of graftable and fully functional skin substitutes is still far from being reached. Skin reconstruction, particularly dermis, necessitates cultivation and maturation for several weeks (>3 weeks) to recover the tissue's composition and functions, which prevent its transfer to clinical applications. Thus, several strategies, including 3D bioprinting, have been explored to accelerate these productions. In the present study, based on the successful application of 3D bioprinting achieved by our group for skin reconstruction in 21 days, we propose to detail the biological behaviors and maturation phases occurring in the bioprinted skin construct thanks to a descriptive approach transferred from the bioprocess field. The aim is to comprehensively characterize dermis construct maturation phases (cell proliferation and ECM secretion) to master later the interdependent and consecutive mechanisms involved in in-vitro production. Thus, standardized quantitative techniques were deployed to describe 3D bioprinted dermis proliferation and maturation phases. Then, in a second step, various parameters potentially impacting the dermis reconstruction phases were evaluated to challenge our methodology and reveal the biological behavior described (fibroblast proliferation and migration, cell death, ECM remodeling with MMP secretion). The parameters studied concern the bioprinting practice including various printed geometries, bioink formulations and cellular physiology in relation with their nutritional supplementation with selected medium additives.

Bioprinting is a cutting-edge technique for creating tissue construction by using cells and biomaterials. This emerging technique created a positive revolution in the field of regenerative medicine. To get tailor-made tissue constructs computer assisted bioprinting technology was in use to get precise results. To improve the precision nanocomposite was used in bio-ink to enhance the performance. A wide variety of nanomaterials were used to create nanocomposites such as to increase functionality. In general, nanomaterials made up of metals, silicon, ceramic, and cellulose carbon were used according to the needs. This study focuses on the current advancements of 3D bioprinting bio-inks made up of varied nanocomposites incorporated with cells with a detailed mention of its fluid resistance, flow, elasticity, shearing stress, fidelity, integrity, strength, printing characteristics, and also its biocompatibility in the biological system. The interaction of biomaterial with cells is examined to elucidate the connections between them. Also, the advantages of each nanocomposite and its uses in the medical field were summarized. The limitations of each nanocomposite were also prospectively reviewed irrespective of their potency to kindle the research towards tailor-made inks according to the needs of the patients with sustainable features in multi-dimensional ways in terms of performance, printability durability, and compatibility.

The assessment of the neo-left ventricular outflow tract (neo-LVOT) area is an essential metric for pre-procedural imaging when screening patients for transcatheter mitral valve replacement (TMVR) eligibility. Indeed, the implantation of transcatheter heart valves for treating failed annuloplasty band ring (ViR), bioprosthesis (ViV) and mitral valve calcification (ViMAC) can lead to a permanent obstruction of the implanted device (namely, LVOT obstruction). In this study, in silico computational modeling and 3D printing were used to quantify the neo-LVOT area and the resulting hemodynamic outcomes of TMVR. We first simulated the deployment of the SAPIEN 3 Ultra device (Edwards Lifesciences, Irvine, CA) and then evaluated the pressure drop near the LVOT obstruction using computational fluid dynamics. The neo-LVOT area was largest in patients with ViR (453.4 ± 58.1 mm²) compared to patients with ViV (246.6 ± 109.5 mm²) and ViMAC (155.6 ± 46.1 mm²). The pressure drop near the LVOT obstruction differed among patients with TMVRs and significantly correlated with the magnitude of the neo-LVOT area (R = −0.761 and P-value = 0.047). The present study highlights the potential of in silico and 3D printed models for planning TMVR procedures and for carrying out a risk evaluation of the device protrusion into the left heart when treating failed mitral valves.

Hydroxyapatite (HA) is a promising support structure for tissue engineering that has considerably gained a lot of interest in recent years due to its potential applications in the biomedical industry and biocompatibility characteristics to make easier proliferation and cellular growth tissue implants in patient. Different materials, notably heterogeneous biomaterials characterized as matrix material and strengthening materials have recently been suggested as materials that can be utilized to produce scaffolds with better bioactive features. Depending on the chemical resemblance of HA with inorganic cultural and biological mineralized structures, considerable innovations have been devoted to hydroxyapatite (HA)-reinforced materials, mainly focusing on bone tissue development. To produce artificial porous bone in structure is challenging with conventional processes. Additive manufacturing (AM) offers a precise, reproductive, and accurate approach to fabricating complex and functional geometry of biomedical materials such as internal microporous structures in a layer-by-layer fashion from three-dimensional models. The present review identified the recent development of AM methods in producing HA-reinforced composite and biocomposites materials such as cellular components. It highlighted and reviewed different AM technologies used in the fabrication of HA and its composite materials and mechanical properties of HA scaffold produced by AM. The reviewed study present a comprehensive overview of the discussed technologies and suggestions for future perspectives to provide a comprehensive view of the techniques explored and complexities in this evolving field.

While being the most extensively used cell type for spheroid-based 3D extrusion bioprinting, mesenchymal stromal cells (MSCs) provide a wide spectrum of biological properties depending on their origin. Understanding the specifics of each heterogeneous MSCs population subgroup would allow one to increase the survivability and functionality of the constructed tissue analogues. To answer this need, this study assessed the survivability, metabolic activity, proliferation, sprouting, migration, and differentiation capacity of MSCs spheroids depending on the cell source (adipose tissue, AT-MSCs/gingiva, G-MSCs) and on the tissue construct's geometry (bioprinted/manually mixed). This study has demonstrated that the cell origin defines the dynamics of spheroid reactivation, resulting in a varying construct's morphology after a 14-days-long cultivation period. AT-MSCs migrate in the hydrogel faster, forming clusters of wide and short sprouts. G-MSCs, oppositely, produce thin, long, and branched sprouts. Hence, AT-MSCs can quickly populate the hydrogel volume, achieving a high cell density, while G-MSCs can cover larger areas, but with a more sprout-like phenotype.

Cartilage regeneration remains a challenge in the field of regenerative medicine. Advances in cartilage regeneration would greatly benefit patients requiring reconstructive surgeries as a result of injury or congenital deformities. Injury can be of the form of trauma or congenital deformities such as microtia, where afflicted children are born with a deformed ear and consequently often experience self-confidence and other psychological issues. Prevalence rates vary among regions but may be as high as 17.4 per 10,000 births. Current treatments for people with this condition are inadequate, with patients requiring multi-stage surgeries or expensive synthetic replacements. There is promise that damaged or missing elastic cartilage could be replaced using biofabrication techniques and technologies. Biofabrication employs cell-laden, tissue compatible and biodegradable scaffolds to then be transplanted into a patient and regenerate the naturally missing tissue that conforms to the defect. Elastin is a highly insoluble structural protein and is found in the extracellular matrix (ECM) of elastic tissues; where it provides the tissues with their elasticity. There is currently no reported literature of direct investigation of the functional role of elastin fibres in auricular cartilage. This review will therefore explore the potential of regenerating auricular cartilage using 3D techniques and technologies with the goal to incorporate or facilitate the production of the elastin content of native cartilage.