3D Bioplotter Research Papers

This work investigated a new 3D-printing methodology to prepare porous scaffolds containing horizontal pore and composition gradients. To achieve that, a multimaterial printing technology developed in our laboratory was adapted to incorporate pore gradients. Fibers were printed by welding segments with unique material compositions and fiber diameters. Particularly, we focused on the preparation of model composite poly(ε-caprolactone)-based scaffolds with radial gradients of particulate hydroxyapatite (HA) content (higher concentrations in the outer region of the scaffold) and porosity (higher in the inner region). The morphology of the scaffolds revealed that the methodology allowed the fabrication of discrete regions with compressive mechanical…

Super-paramagnetic iron oxide nanoparticles (SPIONs) have multiple theranostics applications such as T2 contrast agent in magnetic resonance imaging (MRI) and electromagnetic manipulations in biomedical devices, sensors, and regenerative medicines. However, SPIONs suffer from the limitation of free radical generation, and this has a certain limitation in its applicability in tissue imaging and regeneration applications. In the current study, we developed a simple hydrothermal method to prepare carbon quantum dots (CD) doped SPIONs (FeCD) from easily available precursors. The nanoparticles are observed to be cytocompatible, hemocompatible, and capable of scavenging free radicals in vitro. They also have been observed to be…

Flexible graphene film can be quickly realized by three-dimensional printing (3D printing), which has the potential in functional electronic devices. With a trace of cobalt ions as crosslinker, the graphene oxide sol can be converted into 3D printed ink, overcoming the disadvantage of insufficient viscosity of pure graphene oxide ink. The various graphene architectures were successfully obtained by 3D printing, moreover, graphene/polyaniline composites were obtained by electropolymerization. The specific capacitance of graphene/polyaniline electrode achieved up to 238 F/g at the current density of 0.5 A/g, which was much higher than that of graphene electrode (35 F/g).

Abrasive flow machining (AFM) is a nontraditional surface finishing method that finishes complex surface by pushing the abrasive media flow through the workpiece surface. The entrance effect that the material removal increases at the entrance of changing the cross-sectional flow channel is a difficult problem for AFM. In this paper, the effects of media rheological properties on the entrance effect are discussed. To explore the effects of the media’s viscoelasticity on the entrance effect, two sets of media with different viscoelasticity properties are adopted to study their rheological and machining performances in the designed flow channel with a contraction area….

Three-dimensional (3D) bioprinting is a promising technique used to fabricate scaffolds from hydrogels with living cells. However, the printability of hydrogels in bioprinting has not been adequately studied. The aim of this study was to quantitatively characterize the printability and cell viability of alginate dialdehyde (ADA)-gelatin (Gel) hydrogels for bioprinting. ADA-Gel hydrogels of various concentrations were synthesized and characterized using Fourier transform infrared spectroscopy, along with rheological tests for measuring storage and loss moduli. Scaffolds (with an area of 11 × 11 mm) of 1, 2, and 13 layers were fabricated from ADA-Gel hydrogels using a 3D-bioplotter under printing conditions…

In the present work we have revisited the application of quantitative ultrasound imaging (QUI) to cellular hydrogels, by using the reference phantom method (RPM) in combination with a local attenuation compensation algorithm. The investigated biological samples consisted of cell-laden collagen hydrogels with PC12 neural cells. These cell-laden hydrogels were used to calibrate the integrated backscattering coefficient (IBC) as a function of cell density, which was then used to generate parametric images of local cell density. The image resolution used for QUI and its impact on the relative IBC error was also investigated. Another important contribution of our work was the…

3D printing is used to fabricate tissue scaffolds. The polymer chains in these objects are typically unoriented. The mechanical properties of these scaffolds can be significantly enhanced by proper alignment of the polymer chains. But, post-processing routes to increase orientation can be limited by the geometry of the printed object. Here we show that it is possible to orient the polymer chains during printing by optimizing the printing parameters to take advantage of the flow characteristics of the polymer. This is demonstrated by printing a polymeric scaffold for meniscus regeneration using poly(desaminotyrosyl-tyrosine dodecyl dodecanedioate), poly(DTD DD). Alignment of the polymer…

The fabrication of bone tissue engineering scaffolds with high osteogenic ability and favorable mechanical properties is of huge interest. In this study, a silk fibroin (SF) solution of 30 wt% was extracted from cocoons and combined with mesoporous bioactive glass (MBG) to fabricate MBG/SF composite scaffolds by 3D printing. The porosity, compressive strength, degradation and apatite forming ability were evaluated. The results illustrated that MBG/SF scaffolds had superior compressive strength (ca. 20 MPa) and good biocompatibility, and stimulated bone formation ability compared to mesoporous bioactive glass/polycaprolactone (MBG/PCL) scaffolds. We subcutaneously transplanted hBMSCs-loaded MBG/SF and MBG/PCL scaffolds into the back of nude mice…

Purpose A 3D-Bioplotter® was employed to 3D print (3DP) a humic acid-polyquaternium 10 (HA-PQ10) controlled release fixed dose combination (FDC) tablet comprising of the anti-HIV-1 drugs, efavirenz (EFV), tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC). Methods Chemical interactions, surface morphology and mechanical strength of the FDC were ascertained. In vitro drug release studies were conducted in biorelevant media followed by in vivo study in the large white pigs, in comparison with a market formulation, Atripla®. In vitro-in vivo correlation of results was undertaken. Results EFV, TDF and FTC were successfully entrapped in the 24-layered rectangular prism-shaped 3DP FDC with a…

Lower back pain (LBP), which is strongly associated with intervertebral disc (IVD) degeneration, is one of the most frequently reported age- and work-related disorder in actual society, leading to a huge socio-economic impact worldwide. The current treatments have poor clinical outcomes and do not consider each patient needs. Thus, there is a growing interest in the potential of personalized cell-based tissue engineering (TE) approaches aimed to regenerate the damaged IVD and efficiently restore full disc function. In this work, a bioink composed by silk fibroin (SF) hydrogel combined with elastin was used to bioprint patient-specific substitutes mimicking IVD ultrastructure, in…