Rheological Investigation of Collagen, Fibrinogen, and Thrombin Solutions for Drop-on-Demand 3D Bioprinting

Author(s):  
Hemanth Gudapati ◽  
Daniele Parisi ◽  
Ralph H. Colby ◽  
Ibrahim Ozbolat

<p>Collagen, fibrinogen, and thrombin proteins in aqueous buffer solutions are widely used as precursors of natural biopolymers for three-dimensional (3D) bioprinting applications. The proteins are sourced from animals and their quality may vary from batch to batch, inducing differences in the rheological properties of such solutions. In this work, we investigate the rheological response of collagen, fibrinogen, and thrombin protein solutions in bulk and at the solution/air interface. Interfacial rheological measurements show that fibrous collagen, fibrinogen and globular thrombin proteins adsorb and aggregate at the solution/air interface, forming a viscoelastic solid film at the interface. The viscoelastic film corrupts the bulk rheological measurements in rotational rheometers by contributing to an apparent yield stress, which increases the apparent bulk viscosity up to shear rates as high as 1000 s<sup>-1</sup>. The addition of a non-ionic surfactant, such as polysorbate 80 (PS80) in small amounts between 0.001 and 0.1 v/v%, prevents the formation of the interfacial layer, allowing the estimation of true bulk viscosity and viscoelastic properties of the solutions. The estimation of viscosity not only helps in identifying those protein solutions that are potentially printable with drop-on-demand (DOD) inkjet printing but also detects inconsistencies in flow behavior among the batches.</p>

2020 ◽  
Author(s):  
Hemanth Gudapati ◽  
Daniele Parisi ◽  
Ralph H. Colby ◽  
Ibrahim Ozbolat

<p>Collagen, fibrinogen, and thrombin proteins in aqueous buffer solutions are widely used as precursors of natural biopolymers for three-dimensional (3D) bioprinting applications. The proteins are sourced from animals and their quality may vary from batch to batch, inducing differences in the rheological properties of such solutions. In this work, we investigate the rheological response of collagen, fibrinogen, and thrombin protein solutions in bulk and at the solution/air interface. Interfacial rheological measurements show that fibrous collagen, fibrinogen and globular thrombin proteins adsorb and aggregate at the solution/air interface, forming a viscoelastic solid film at the interface. The viscoelastic film corrupts the bulk rheological measurements in rotational rheometers by contributing to an apparent yield stress, which increases the apparent bulk viscosity up to shear rates as high as 1000 s<sup>-1</sup>. The addition of a non-ionic surfactant, such as polysorbate 80 (PS80) in small amounts between 0.001 and 0.1 v/v%, prevents the formation of the interfacial layer, allowing the estimation of true bulk viscosity and viscoelastic properties of the solutions. The estimation of viscosity not only helps in identifying those protein solutions that are potentially printable with drop-on-demand (DOD) inkjet printing but also detects inconsistencies in flow behavior among the batches.</p>


Soft Matter ◽  
2020 ◽  
Vol 16 (46) ◽  
pp. 10506-10517 ◽  
Author(s):  
Hemanth Gudapati ◽  
Daniele Parisi ◽  
Ralph H. Colby ◽  
Ibrahim T. Ozbolat

Collagen, fibrinogen, and thrombin proteins in aqueous buffer solutions are widely used as precursors of natural biopolymers in three-dimensional (3D) bioprinting applications.


2021 ◽  
Author(s):  
Robert H. Utama ◽  
Vincent T. G. Tan ◽  
Kristel C. Tjandra ◽  
Andrew Sexton ◽  
Duyen H. T. Nguyen ◽  
...  

AbstractIn vitro three-dimensional (3D) cell models have been accepted to better recapitulate aspects of in vivo organ environment than 2D cell culture. Currently, the production of these complex in vitro 3D cell models with multiple cell types and microenvironments remains challenging and prone to human error. Here we report a versatile bioink comprised of a 4-arm PEG based polymer with distal maleimide derivatives as the main ink component and a bis-thiol species as the activator that crosslinks the polymer to form the hydrogel in less than a second. The rapid gelation makes the polymer system compatible with 3D bioprinting. The ink is combined with a drop-on-demand 3D bioprinting platform consisting of eight independently addressable nozzles and high-throughput printing logic for creating complex 3D cell culture models. The combination of multiple nozzles and fast printing logic enables the rapid preparation of many complex 3D structures comprising multiple hydrogel environments in the one structure in a standard 96-well plate format. The platform compatibility for biological applications was validated using pancreatic ductal adenocarcinoma cancer (PDAC) cells with their phenotypic responses controlled by tuning the hydrogel microenvironment.


2021 ◽  
pp. 2100125
Author(s):  
Robert H. Utama ◽  
Vincent T. G. Tan ◽  
Kristel C. Tjandra ◽  
Andrew Sexton ◽  
Duyen H. T. Nguyen ◽  
...  

1998 ◽  
Vol 542 ◽  
Author(s):  
N. Reis ◽  
K. A. M. Seerden ◽  
B. Derby ◽  
J. W. Halloran ◽  
J. R. G. Evans

AbstractIn order to successfully build three-dimensional shapes by hot-melt inkjet deposition it is essential to control the building block characteristics, i.e., the deposit geometry, dimensions and fine feature resolution. The deposit formation is mainly dependent on the material systems and their jetting behaviour. It is therefore crucial to understand how the jet formation is affected by the inks 'rheological properties and how to manipulate the jet-head driving parameters to achieve optimum deposition conditions. This paper reports our investigations with a model jet firing station, about the influence of driving parameters of hot-melt drop-on-demand print-heads (e.g., pulse shape and frequency) on the jet and deposit formation characteristics, for both unfilled and powder loaded vehicles.


2021 ◽  
Vol 7 (2) ◽  
Author(s):  
Wei Long Ng ◽  
Teck Choon Ayi ◽  
Yi-Chun Liu ◽  
Swee Leong Sing ◽  
Wai Yee Yeong ◽  
...  

The global prevalence of respiratory diseases caused by infectious pathogens has resulted in an increased demand for realistic in-vitro alveolar lung models to serve as suitable disease models. This demand has resulted in the fabrication of numerous two-dimensional (2D) and three-dimensional (3D) in-vitro alveolar lung models. The ability to fabricate these 3D in-vitro alveolar lung models in an automated manner with high repeatability and reliability is important for potential scalableproduction. In this study, we reported the fabrication of human triple-layered alveolar lung models comprising of human lung epithelial cells, human endothelial cells, and human lung fibroblasts using the drop-on-demand (DOD) 3D bioprinting technique. The polyvinylpyrrolidone-based bio-inks and the use of a 300 μm nozzle diameter improved the repeatability of the bioprinting process by achieving consistent cell output over time using different human alveolar lung cells. The 3D bioprintedhuman triple-layered alveolar lung models were able to maintain cell viability with relative similar proliferation profile over time as compared to non-printed cells. This DOD 3D bioprinting platform offers an attractive tool for highly repeatable and scalable fabrication of 3D in-vitro human alveolar lung models.


2020 ◽  
Vol 21 (10) ◽  
pp. 3482 ◽  
Author(s):  
Brian E. Grottkau ◽  
Zhixin Hui ◽  
Yonggang Pang

Drop-on-demand (DOD) 3D bioprinting technologies currently hold the greatest promise for generating functional tissues for clinical use and for drug development. However, existing DOD 3D bioprinting technologies have three main limitations: (1) droplet volume inconsistency; (2) the ability to print only bioinks with low cell concentrations and low viscosity; and (3) problems with cell viability when dispensed under high pressure. We report our success developing a novel direct-volumetric DOD (DVDOD) 3D bioprinting technology that overcomes each of these limitations. DVDOD can produce droplets of bioink from <10 nL in volume using a direct-volumetric mechanism with <± 5% volumetric percent accuracy in an accurate spatially controlled manner. DVDOD has the capability of dispensing bioinks with high concentrations of cells and/or high viscosity biomaterials in either low- or high-throughput modes. The cells are subjected to a low pressure during the bioprinting process for a very short period of time that does not negatively impact cell viability. We demonstrated the functions of the bioprinter in two distinct manners: (1) by using a high-throughput drug-delivery model; and (2) by bioprinting micro-tissues using a variety of different cell types, including functional micro-tissues of bone, cancer, and induced pluripotent stem cells. Our DVDOD technology demonstrates a promising platform for generating many types of tissues and drug-delivery models.


Author(s):  
Long Zhao ◽  
Karen Chang Yan ◽  
Rui Yao ◽  
Feng Lin ◽  
Wei Sun

Drop-on-demand (DOD) microdroplet formation and deposition play an important role in additive manufacturing, particularly in printing of three-dimensional (3D) in vitro biological models for pharmacological and pathological studies, for tissue engineering and regenerative medicine applications, and for building of cell-integrated microfluidic devices. In development of a DOD based microdroplet deposition process for 3D cell printing, the droplet formation, controlled on-demand deposition and at the single-cell level, and most importantly, maintaining the viability and functionality of the cells during and after the printing are all remaining to be challenged. This report presents our recent study on developing a novel DOD based microdroplet deposition process for 3D printing by utilization of an alternating viscous and inertial force jetting (AVIFJ) mechanism. The results include an analysis of droplet formation mechanism, the system configuration, and experimental study of the effects of process parameters on microdroplet formation. Sodium alginate solutions are used for microdroplet formation and deposition. Key process parameters include actuation signal waveforms, nozzle dimensional features, and solution viscosity. Sizes of formed microdroplets are examined by measuring the droplet diameter and velocity. Results show that by utilizing a nozzle at a 45 μm diameter, the size of the formed microdroplets is in the range of 52–72 μm in diameter and 0.4–2.0 m/s in jetting speed, respectively. Reproducibility of the system is also examined and the results show that the deviation of the formed microdroplet diameter and the droplet deposition accuracy is within 6% and 6.2 μm range, respectively. Experimental results demonstrate a high controllability and precision for the developed DOD microdroplet deposition system with a potential for precise cell printing.


2021 ◽  
Author(s):  
Sagil James ◽  
Samir Mulgaonkar

Abstract Used mainly for manufacturing operative tissue structures to replace damaged ones, Three-dimensional (3D) Bioprinting is a burgeoning area of medical science with enormous potential. Since the technology is still relatively new, 3D bioprinting heavily relies on the trial-and-error approach for advancement, but the general process currently involves a mixture of various biomaterials in hydrogel form. The quality of the results is affected significantly by the parameters by which the print is made. Even the most seemingly minute details can drastically change the outcome of the print, including temperature, print time, the speed of the occurring print and nozzle diameter, dispensing pressure, and more. The biomaterial used is also of the utmost importance. Based on current results, an ideal biomaterial should include the same or similar chemical, biological, mechanical, and practical properties of the target end structure. It is critical to ascertain the closest parameters available to ensure a quality end resulting print. The proposed studies' goal is to determine and streamline process parameters to the nearest possible degree to optimize the bioprinting process of hybrid bioinks. Using material made from unchanged alginate, alginate with gelatin, and combined amino acids and derivatives with diphenylalanine, the medical properties of each biomaterial were examined, as well as their flow behavior, allowing a certain level of predictability on printing parameters. Printing parameters, as described, are the parameters by which we can predict how well a target structure can be accurately constructed using various bio-inks. Ultimately, the results have indicated that printing parameters primarily hinges on the composition of the hydrogels used and the pressure by which it was distributed. This study also presented a detailed frame of reference to assess amino acids and derivatives with diphenylalanine systematically, which can also be used in other areas of 3D bioprinting.


Author(s):  
Changxue Xu ◽  
Zhengyi Zhang ◽  
Kyle Christensen ◽  
Yong Huang ◽  
Jianzhong Fu ◽  
...  

Organ printing, among different tissue engineering innovations, is a freeform fabrication approach for making three-dimensional (3D) tissue and organ constructs using cellular spheroids or bioinks as building blocks. The capability to fabricate vascular-like tubular constructs is an important indicator of the overall feasibility of envisioned organ printing technology. In this study, vascular-like alginate tubes, which mimic typical vascular constructs, are fabricated both vertically and horizontally using drop-on-demand (DOD) inkjetting. Manufacturing-related challenges are different for the vertical and horizontal printing configurations. In general, the vertical printing configuration has instability or collapse/buckling problems and may experience some difficulty in fabricating complex constructs such as Y- or K-shaped constructs if there is no supporting material. The horizontal printing configuration may easily result in a deformed hollow cross section and may require extra effort to mitigate the undesired deformation. It is envisioned that the combination of vertical and horizontal printing provides an efficient and effective way to fabricate complex tubular constructs with both vertical and horizontal branching features.


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