scholarly journals 3D Printed Microfluidic Spiral Separation Device for Continuous, Pulsation-Free and Controllable CHO Cell Retention

Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1060
Author(s):  
Anton Enders ◽  
John-Alexander Preuss ◽  
Janina Bahnemann

The development of continuous bioprocesses—which require cell retention systems in order to enable longer cultivation durations—is a primary focus in the field of modern process development. The flow environment of microfluidic systems enables the granular manipulation of particles (to allow for greater focusing in specific channel regions), which in turn facilitates the development of small continuous cell separation systems. However, previously published systems did not allow for separation control. Additionally, the focusing effect of these systems requires constant, pulsation-free flow for optimal operation, which cannot be achieved using ordinary peristaltic pumps. As described in this paper, a 3D printed cell separation spiral for CHO-K1 (Chinese hamster ovary) cells was developed and evaluated optically and with cell experiments. It demonstrated a high separation efficiency of over 95% at up to 20 × 106 cells mL−1. Control over inlet and outlet flow rates allowed the operator to adjust the separation efficiency of the device while in use—thereby enabling fine control over cell concentration in the attached bioreactors. In addition, miniaturized 3D printed buffer devices were developed that can be easily attached directly to the separation unit for usage with peristaltic pumps while simultaneously almost eradicating pump pulsations. These custom pulsation dampeners were closely integrated with the separator spiral lowering the overall dead volume of the system. The entire device can be flexibly connected directly to bioreactors, allowing continuous, pulsation-free cell retention and process operation.

Micromachines ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 699
Author(s):  
Rohollah Nasiri ◽  
Amir Shamloo ◽  
Javad Akbari ◽  
Peyton Tebon ◽  
Mehmet R. Dokmeci ◽  
...  

Separation of circulating tumor cells (CTCs) from blood samples and subsequent DNA extraction from these cells play a crucial role in cancer research and drug discovery. Microfluidics is a versatile technology that has been applied to create niche solutions to biomedical applications, such as cell separation and mixing, droplet generation, bioprinting, and organs on a chip. Centrifugal microfluidic biochips created on compact disks show great potential in processing biological samples for point of care diagnostics. This study investigates the design and numerical simulation of an integrated microfluidic device, including a cell separation unit for isolating CTCs from a blood sample and a micromixer unit for cell lysis on a rotating disk platform. For this purpose, an inertial microfluidic device was designed for the separation of target cells by using contraction–expansion microchannel arrays. Additionally, a micromixer was incorporated to mix separated target cells with the cell lysis chemical reagent to dissolve their membranes to facilitate further assays. Our numerical simulation approach was validated for both cell separation and micromixer units and corroborates existing experimental results. In the first compartment of the proposed device (cell separation unit), several simulations were performed at different angular velocities from 500 rpm to 3000 rpm to find the optimum angular velocity for maximum separation efficiency. By using the proposed inertial separation approach, CTCs, were successfully separated from white blood cells (WBCs) with high efficiency (~90%) at an angular velocity of 2000 rpm. Furthermore, a serpentine channel with rectangular obstacles was designed to achieve a highly efficient micromixer unit with high mixing quality (~98%) for isolated CTCs lysis at 2000 rpm.


1992 ◽  
Vol 67 (03) ◽  
pp. 366-370 ◽  
Author(s):  
Katsuhiko Nawa ◽  
Teru Itani ◽  
Mayumi Ono ◽  
Katsu-ichi Sakano ◽  
Yasumasa Marumoto ◽  
...  

SummaryPrevious studies on recombinant human soluble thrombomodulin (rsTM) from Chinese hamster ovary cells revealed that rsTM was expressed as two proteins that differed functionally in vitro due to the presence (rsTMp) or absence (rsTMa) of chondroitin-4-sulfate. The current study evaluates the in vivo behavior of rsTM in rats and in a rat model of tissue factor-induced disseminated intravascular coagulation (DIC). rsTMp was more potent than rsTMa for prolongation of the activated partial thromboplastin time (APTT) and their in vivo half-lives determined by ELISA were 20 min for rsTMp and 5.0 h for rsTMa. Injection of a tissue factor suspension (5 mg/kg) resulted in DIC as judged by decreased platelet counts and fibrinogen concentrations, prolonged APTT, and increased fibrin and fibrinogen degradation products (FDP) levels. A bolus injection of either rsTM (0.2 mg/kg) 1 min before induction of DIC essentially neutralized effects on platelets, fibrinogen, and FDP levels, and had only a moderate effect on APTT prolongation. The dose of anticoagulant to inhibit the drop in platelet counts by 50% (ED50) was 0.2 mg/kg rsTMa, 0.07 mg/kg rsTMp, and 7 U/ kg heparin. The effect of increasing concentrations of rsTM and heparin on bleeding times were compared in experiments involving incision of the rat tail. Doubling of the bleeding times occurred at 5 mg/kg rsTMa, 3 mg/kg rsTMp or 90 U/kg heparin. These values represent a 25-fold increase over the ED50 for rsTMa, 43-fold for rsTMp and 13-fold for heparin. These results suggest that rsTMp is a potent anticoagulant to inhibit the platelet reduction when injected prior to the induction of DIC in rats.


1993 ◽  
Vol 70 (03) ◽  
pp. 418-422 ◽  
Author(s):  
Masaharu Aritomi ◽  
Naoko Watanabe ◽  
Rika Ohishi ◽  
Komakazu Gomi ◽  
Takao Kiyota ◽  
...  

SummaryRecombinant human soluble thrombomodulin (rhs-TM), having no transmembrane domain or chondroitin sulfate, was expressed in Chinese hamster ovary cells. Interactions between rhs-TM, thrombin (Th), protein C (PC) and antithrombin III (ATIII) were studied. Equilibrium between rhs-TM and Th had no detectable time lag in clotting inhibition (K d = 26 nM) or PC activation (K d = 22 nM), while ATIII inhibited Th at a bimolecular rate constant = 5,200 M-1s-1 (K d <0.2 nM). A mixture of ATIII, Th and rhs-TM showed that ATIII reacted with Th slower than rhs-TM, whose presence did not affect the reaction between ATIII and Th. In a mixture of rhs-TM, ATIII and PC, the repeated addition of Th caused the repeated activation of PC; which was consistent with the Simulation based on the assumption that rhs-TM is recycled as a Th cofactor. From these results, we concluded that upon inhibition of the rhs-TM-Th complex by ATIII, rhs-TM is released to recombine with free Th and begins to activate PC, while the Th-ATIII complex does not affect rhs-TM-Th equilibrium.


Pathology ◽  
1993 ◽  
Vol 25 (3) ◽  
pp. 268-276 ◽  
Author(s):  
Wanda B. Mackinnon ◽  
Marlen Dyne ◽  
Rebecca Hancock ◽  
Carolyn E. Mountford ◽  
Adrienne J. Grant ◽  
...  

1988 ◽  
Vol 20 (2) ◽  
pp. 143-152 ◽  
Author(s):  
A. Langi ◽  
M. Priha

The mutagenic properties of pulp and paper mill effluents were studied in three mills: bleached kraft mill with aerated lagoon treatment (Mill 1), bleached kraft mill with activated sludge treatment (Mill 2) and mechanical pulp/paper mill (Mill 3). Both treated and untreated effluents, process streams and molecular fractions were tested for mutagenicity (Ames test. Salmonella typhimurium TA100 and SCE sister chromatid exchange test, Chinese hamster ovary cells). To verify the potential environmental effects the mutagenic activity of concentrated recipient lake water (Mill 2) was also studied. The Ames mutagenicity of the bleached kraft mill effluent (BKME) originated from the first chlorination filtrate, SCE mutagenicity also occurred in the alkali extraction stage filtrate (Mill 1). No Ames mutagenicity was detected in the paper mill effluent, but it was SCE mutagenic. Activated sludge treatment of BKME removed both Ames and SCE mutagenicity, but the aerated lagoon treated BKME was still SCE mutagenic. No mutagenic activity was detected in the recipient water concentrates.


Author(s):  
Shazid Md. Sharker ◽  
Md. Atiqur Rahman

Most of clinical approved protein-based drugs or under in clinical trial have a profound impact in the treatment of critical diseases. The mammalian eukaryotic cells culture approaches, particularly the CHO (Chinese Hamster Ovary) cells are mainly used in the biopharmaceutical industry for the mass-production of therapeutic protein. Recent advances in CHO cell bioprocessing to yield recombinant proteins and monoclonal antibodies have enabled the expression of quality protein. The developments of cell lines are possible to upgrade specific productivity. As a result, it holds an interesting area for academic as well as industrial researchers around the world. This review will concentrate on the recent progress of the mammalian CHO cells culture technology and the future scope of further development for the mass-production of protein therapeutics.


2019 ◽  
Vol 16 (10) ◽  
pp. 837-845
Author(s):  
Sandhya Jonnala ◽  
Bhaskar Nameta ◽  
Murthy Chavali ◽  
Rajashaker Bantu ◽  
Pallavi Choudante ◽  
...  

A class of 1-((benzo[d]thiazol-2-ylamino)(phenyl)methyl)naphthalen-2-ol derivatives (4a-t) has been synthesized in good yields through a three component coupling reaction. The newly synthesized compounds were evaluated for their in vitro antiproliferative activity against five cell lines such as DU145 (human prostate cancer), MDA-MB-B231 (human breast cancer), SKOV3 (human ovarian cancer), B16-F10 (mouse skin melanoma) and CHO-K1 (Chinese hamster ovary cells), a noncancerous cell line. In vitro inhibitory activity indicates that compounds 4a, 4b, 4c, 4d, 4g, 4j, and 4o exhibited potent anti-proliferative behavior. Among them, compounds 4g, 4j and 4o found to be the most active members exhibiting remarkable growth inhibitory activity. Molecular docking facilitates to investigate the probable binding mode and key active site interactions in tubulins α and β proteins. The docking results are complementary to experimental results.


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