3D Bioplotter Research Papers

In this work, we synthesized a novel polymeric biomaterial platform with tunable functionalizability for extrusion-based 3D printing. Biodegradable polymers were synthesized using 4-hydroxyphenethyl 2-(4-hydroxyphenyl)acetate (HTy), which is derived from Tyrosol and 2-(4-hydroxyphenyl)acetic acid. p-Phenylenediacetic acid (PDA) was introduced to enhance crystallinity. To enable functionalizability without deteriorating printability, glutamic acid derivatives were introduced into the polymer design, forming copolymers including poly(HTy-co-45%PDA-co-5%Gluhexenamide ester) (HP5GH), poly(HTy-co-45%PDA-co-5%Glupentynamide ester) (HP5GP), and poly(HTy-co-45%PDA-co-5%BocGlu ester) (HP5BG). The resulting polymers have: two melting temperatures (125–131 °C and 141–147 °C), Young’s moduli of 1.9–2.4 GPa, and print temperatures of 170–190 °C. The molecular weight (Mw) loss due to hydrolytic…

Three-dimensional (3D) printing has enabled benchtop fabrication of customized bioengineered constructs with intricate architectures. Various approaches are being explored to enable optimum integration of such constructs into the physiological environment including addition of bioactive fillers. In this work, we incorporated a corticosteroid drug, dexamethasone (Dex), in a low modulus polyester (SC5050) and examined the effect of Dex incorporation on solvent-, initiator-, and monomer-free pneumatic extrusion-based 3D printing of the polymer. Dex–SC5050 interactions were characterized by plotting thermodynamic binary phase diagrams based on the Flory–Huggins theory. The effect of Dex composition on the 3D printability of the SC5050 polyester was examined…

In this work, we present a printing method to fabricate scaffolds consisting of multimaterial segmented fibers. Particularly, we developed a reproducible printing process to create single fibers with multiple discrete compositions and control over the distribution of particulate ceramics—namely hydroxyapatite (HA) and β-tricalcium phosphate (TCP)—within poly(ɛ-caprolactone)-based composite scaffolds. Tensile testing revealed that the mechanical integrity of individual segmented fibers was preserved compared with nonsegmented fibers, and microcomputed tomography and thermal analysis confirmed the homogeneous distribution of ceramics incorporated in the fiber compositions. Moreover, we printed and characterized composite scaffolds containing model inverse radial gradients of HA and TCP that could…

Fast and accurate manufacturing of individually tailored solid dosage forms is one of the main challenges for personalized medicine. The use of 3D printers has recently been studied to determine their suitability for personalized drug manufacturing. In the current work, formulations free of organic solvents were developed for a pressure-assisted microsyringe printing method (PAM). The water soluble polymer polyvinyl alcohol-polyethylene glycol graft copolymer (PVA-PEG) was used as matrix, while levetiracetam (LEV) was used as model drug. Furthermore, the influence of a second polymer, polyvinylpyrrolidone-vinyl acetate copolymer (PVP-PVAc) on the properties of the printed tablets was investigated. Tablets were printed using…

Whereas the rigid nature of standard thermoelectrics limits their use, flexible thermoelectric platforms can find much broader applications, for example, in low-power, wearable energy harvesting for internet-of-things applications. Here we realize continuous, flexible thermoelectric threads via a rapid extrusion of 3D-printable composite inks (Bi2Te3 n- or p-type micrograins within a non-conducting polymer as a binder) followed by compression through a roller-pair, and we demonstrate their applications in flexible, low-power energy harvesting. The thermoelectric power factors of these threads are enhanced up to 7 orders-of-magnitude after lateral compression, principally due to improved conductivity resulting from reduced void volume fraction and partial…

Calcium phosphate (CaPs)-based nanostructures are mostly known to induce osteogenic differentiation of mesenchymal stem cells (MSCs). However, in the current study, doping of carbon quantum dots into calcium phosphate nanorods (C-CaPs) has been observed to affect the differentiation pathway and enhanced the expression of chondrogenic genes instead of osteogenic ones. Here, we report a microwave-assisted single-step synthesis and doping of carbon dot into calcium phosphate nanorods and their ectopic chondrogenicity in a rodent subcutaneous model. High-resolution transmission electron microscopy, X-ray powder diffraction, and X-ray photoelectron spectroscopy studies show that the doping of carbon dots results in p-type semiconductor-like structure formation…

STUDY QUESTION Does the upregulation of the zinc finger E-box binding homeobox 2 (ZEB2) transcription factor in human trophoblast cells lead to alterations in gene expression consistent with an epithelial-mesenchymal transition (EMT) and a consequent increase in invasiveness? SUMMARY ANSWER Overexpression of ZEB2 results in an epithelial-mesenchymal shift in gene expression accompanied by a substantial increase in invasive capacity of human trophoblast cells.

Background: The presence and progression of neuromuscular pathologies, including spasticity, dystrophy and hyperthyroidism, have been correlated with changes in the intrinsic mechanical properties of skeletal muscle tissue. Tools of noninvasively measuring and monitoring these properties, such as Magnetic Resonance Elastography (MRE), could benefit basic research into understanding neuromuscular pathologies, as well as translational research to develop therapies, by providing a means of assessing and tracking their efficacy. While various approaches have been proposed in the literature [1,2], there is not yet an accepted standard for the identification of the mechanical properties of anisotropic and viscoelastic tissues through MRE; advances in…

Gelatin methacryloyl is a promising material in tissue engineering and has been widely studied in three-dimensional bioprinting. Although gelatin methacryloyl possesses excellent biocompatibility and tunable mechanical properties, its poor printability/processability has hindered its further applications. In this study, we report a reversible physical crosslinking strategy for precise deposition of human chondrocyte-laden gelatin methacryloyl bioink at low concentration without any sacrificial material by using extrusive three-dimensional bioprinting. The precise printing temperature was determined by the rheological properties of gelatin methacryloyl with temperature. Ten percent (w/v) gelatin methacryloyl was chosen as the printing formula due to highest biocompatibility in three-dimensional cell cultures…

The direct use of graphene for potential thermoelectric material requires the opening of its bandgap without loss of its high electric conductivity. We herein demonstrate a synchronous reduction and assembly strategy to fabricate large-area reduced graphene oxide films with high electric conductivity and optimized low thermal conductivity assembly. The reduced graphene oxide films have a high electric conductivity and low thermal conductivity, which results from high longitudinal carrier mobility of the lattice domains as well as the enhanced scattering of phonons in the defects and their boundary that substantially reduces the mean phonon free path and the thermal conductivity. Flexible…