High biocompatibility was observed in both ultrashort peptide bioinks, which effectively facilitated chondrogenic differentiation within human mesenchymal stem cells. Gene expression within differentiated stem cells, cultured with ultrashort peptide bioinks, displayed a predilection for articular cartilage extracellular matrix creation. Utilizing the differing mechanical stiffnesses of the two ultra-short peptide bioinks, it is possible to fabricate cartilage tissue exhibiting diverse zones, including the articular and calcified cartilage, which are fundamental for the integration of engineered tissues.
Full-thickness skin defects could potentially be treated with a customized approach utilizing rapidly produced 3D-printed bioactive scaffolds. To enhance wound healing, decellularized extracellular matrices and mesenchymal stem cells have been proven effective. Adipose tissues harvested through liposuction are replete with adipose-derived extracellular matrix (adECM) and adipose-derived stem cells (ADSCs), rendering them a naturally occurring source of bioactive materials for the process of 3D bioprinting. 3D-printed bioactive scaffolds, incorporating ADSC cells and composed of gelatin methacryloyl (GelMA), hyaluronic acid methacryloyl (HAMA), and adECM, were fabricated to exhibit both photocrosslinking capabilities in vitro and thermosensitive crosslinking in vivo. Imlunestrant nmr The bioink, adECM, was crafted from decellularized human lipoaspirate, which was then integrated with GelMA and HAMA as a bioactive component. The adECM-GelMA-HAMA bioink, in contrast to the GelMA-HAMA bioink, exhibited enhanced wettability, degradability, and cytocompatibility. Wound healing in a full-thickness skin defect, observed in a nude mouse model, was augmented by the use of ADSC-laden adECM-GelMA-HAMA scaffolds, demonstrably accelerating neovascularization, collagen secretion, and tissue remodeling. ADSCs and adECM synergistically endowed the bioink with its bioactive properties. This study introduces a novel strategy to improve the biological potency of 3D-bioprinted skin substitutes by the addition of adECM and ADSCs sourced from human lipoaspirate, potentially providing a beneficial therapeutic solution for full-thickness skin losses.
3D-printed products are finding increasing application in medical domains, such as plastic surgery, orthopedics, and dentistry, thanks to the advancements in three-dimensional (3D) printing technology. Shape accuracy in 3D-printed models is becoming a more prominent feature in cardiovascular research. From the perspective of biomechanics, a relatively small number of studies have explored the use of printable materials to accurately represent the human aorta's properties. This study examines the utility of 3D-printed materials in accurately modeling the stiffness found within human aortic tissue. Prior to any further analysis, the biomechanical characteristics of a healthy human aorta were defined as a reference standard. The principal intention of this research was to determine 3D printable materials that share similar properties with the human aorta. colon biopsy culture During their 3D printing, the three synthetic materials, NinjaFlex (Fenner Inc., Manheim, USA), FilasticTM (Filastic Inc., Jardim Paulistano, Brazil), and RGD450+TangoPlus (Stratasys Ltd., Rehovot, Israel), were printed with different thicknesses. To evaluate biomechanical characteristics, encompassing thickness, stress, strain, and stiffness, uniaxial and biaxial tensile tests were undertaken. Employing the composite material RGD450 and TangoPlus, we determined a stiffness akin to a healthy human aorta. Additionally, the 50-shore-hardness RGD450+TangoPlus material demonstrated a similar thickness and stiffness profile as the human aorta.
In several applicative sectors, 3D bioprinting stands as a novel and promising solution for the fabrication of living tissue, showcasing significant potential advantages. However, the creation and integration of sophisticated vascular networks stands as a major constraint in producing complex tissues and growing the bioprinting industry. Within bioprinted constructs, a physics-based computational model is presented to analyze the diffusion and consumption of nutrients. immune suppression Employing the finite element method, the model-A system of partial differential equations describes cell viability and proliferation, adaptable to diverse cell types, densities, biomaterials, and 3D-printed geometries, thereby enabling a pre-assessment of cell viability within the bioprinted structure. Changes in cell viability are predicted by the model, whose accuracy is confirmed through experimental validation on bioprinted samples. The proposed model effectively exemplifies the digital twinning strategy for biofabricated constructs, showcasing its integration potential within the basic tissue bioprinting toolkit.
Wall shear stress, a common consequence of microvalve-based bioprinting, is known to have an adverse effect on the viability of the cells. We posit that the wall shear stress during impingement on the building platform, a factor previously overlooked in microvalve-based bioprinting, may prove more crucial for the viability of the processed cells than the wall shear stress within the nozzle. Numerical simulations of fluid mechanics, employing the finite volume method, were undertaken to validate our hypothesis. Subsequently, two functionally varied cell types, HaCaT cells and primary human umbilical vein endothelial cells (HUVECs), were assessed for their viability within the cell-laden hydrogel after the bioprinting process. Simulation data unveiled that, at low upstream pressures, the kinetic energy was insufficient to triumph over the interfacial forces, thereby preventing droplet formation and detachment. On the contrary, with a pressure that was relatively in the middle of the upstream range, a droplet and a ligament were created; yet, with a stronger upstream pressure, a jet emerged between the nozzle and the platform. When a jet forms, the shear stress caused by impingement may exceed the shear stress along the nozzle's inner wall. A correlation existed between the nozzle-to-platform separation and the amplitude of the impingement shear stress. Cell viability assessments revealed a 10% or less increase when the nozzle-to-platform distance was altered from 0.3 mm to 3 mm, thereby confirming the finding. Ultimately, the shear stress arising from impingement can surpass the wall shear stress within the nozzle during microvalve-based bioprinting. Yet, this essential issue can be resolved by changing the distance between the nozzle and the building's platform. In conclusion, our research underscores the imperative of incorporating impingement-related shear stress as an integral component of bioprinting methods.
Anatomic models are indispensable tools within the medical realm. In contrast, the depiction of the mechanical properties of soft tissues is not completely captured in the construction of mass-produced and 3D-printed models. In this study, a human liver model was printed using a multi-material 3D printer, this model having customized mechanical and radiological properties, for the purpose of contrasting it with its printing material and authentic liver tissue. The main thrust of the endeavor was mechanical realism, with radiological similarity serving as a supporting secondary objective. To achieve tensile properties akin to liver tissue, the materials and internal structure of the printed model were carefully chosen. Printed at a 33% scale and boasting a 40% gyroid infill, the model was crafted from soft silicone rubber, with silicone oil acting as the interstitial fluid. The liver model, having been printed, was subsequently scanned using a CT machine. Given the liver's unsuitable form for tensile testing, specimens were likewise produced via printing. In order to enable a comparison, three liver model replicates, identical in internal structure, were printed, and three more, made of silicone rubber with a complete 100% rectilinear infill, were also produced. In order to compare the elastic moduli and dissipated energy ratios, a four-step cyclic loading test was performed on all specimens. The elastic moduli of the fluid-filled, full-silicone specimens were initially measured as 0.26 MPa and 0.37 MPa, respectively. The dissipated energy ratios, specifically in the second, third, and fourth load cycles, were 0.140, 0.167, and 0.183 for one specimen and 0.118, 0.093, and 0.081 for the other, respectively. In a computed tomography (CT) scan, the liver model exhibited a Hounsfield unit (HU) reading of 225 ± 30. This reading is more indicative of a human liver (70 ± 30 HU) compared to the printing silicone (340 ± 50 HU). Unlike printing solely with silicone rubber, the proposed printing approach enabled the creation of a more realistic liver model in terms of mechanical and radiological characteristics. The demonstration shows that this printing method provides fresh opportunities for personalization in the design of anatomical models.
Devices controlling drug release on demand provide improved patient care. These advanced drug delivery systems allow for the manipulation of drug release schedules, enabling precise control over the release of drugs, thereby increasing the management of drug concentration in the patient. Smart drug delivery devices gain enhanced functionality and broader applications through the incorporation of electronics. 3D-printed electronics, coupled with 3D printing, leads to an appreciable expansion of both the customizability and functionality in such devices. With the evolution of these technologies, the functionality of the devices will be augmented. This review paper investigates the use of 3D-printed electronics and 3D printing in smart drug delivery systems integrated with electronics, in addition to analyzing future developments in such applications.
Intervention is urgently needed for patients with severe burns, causing widespread skin damage, to prevent the life-threatening consequences of hypothermia, infection, and fluid loss. Typical burn treatments involve the surgical removal of the burned skin and its replacement with skin autografts for wound repair.