Shear sensitivity of three hybridoma cell lines in suspension culture

Smith, Craig G.; Greenfield, P. F.; Randerson, David H.

doi:10.1016/b978-0-408-02732-8.50027-4

Cited by 11 publications

(6 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…First, direct perfusion of engineered cardiac tissue exposes cardiac cells to hydrodynamic shear stresses that were estimated to be 1.0 0.1, 0.30 0.002, and 0.19 0.02 dyn/cm 2 for perfusion rates of 3.0, 1.0, and 0.6 mL/min, respectively (Carrier et al, 2002). Although lower than the shear stresses previously reported to aect the morphology and viability of mammalian cells cultured in vitro (1.6±3.3 dyn/cm 2 ; Smith et al, 1987;Stathopoulos and Hellums, 1985), these stresses are higher than physiological for cardiac cells. Second, the cell density of engineered cardiac tissue is only approximately 20±25% of native cardiac tissue per unit wet weight .…”

Section: Discussioncontrasting

confidence: 55%

Effects of oxygen on engineered cardiac muscle

Rupnick

Langer

Schoen

et al. 2002

Biotech & Bioengineering

130

View full text Add to dashboard Cite

Concentration gradients associated with the in vitro cultivation of engineered tissues that are vascularized in vivo result in the formation of only a thin peripheral tissue-like region (e.g., approximately 100 microm for engineered cardiac muscle) around a relatively cell-free interior. We previously demonstrated that diffusional gradients within engineered cardiac constructs can be minimized by direct perfusion of culture medium through the construct. In the present study, we measured the effects of medium perfusion rate and local oxygen concentration (p(O2)) on the in vitro reconstruction of engineered cardiac muscle. Neonatal rat cardiomyocytes were seeded onto biodegradable polymer scaffolds (fibrous discs, 1.1 cm diameter x 2 mm thick, made of polyglycolic acid, 24 x 10(6) cells per scaffold). The resulting cell-polymer constructs were cultured for a total of 12 days in serially connected cartridges (n = 1-8), each containing one construct directly perfused with culture medium at a flow rate of 0.2-3.0 mL/min. In all groups, oxygen concentration decreased due to cell respiration, and depended on construct position in the series and medium flow rate. Higher perfusion rates and higher p(O2) correlated with more aerobic cell metabolism, and higher DNA and protein contents. Constructs cultured at p(O2) of 160 mm Hg had 50% higher DNA and protein contents, markedly higher expression of sarcomeric alpha-actin, better organized sarcomeres and cell junctions, and 4.5-fold higher rate of cell respiration as compared to constructs cultured at p(O2) of 60 mm Hg. Contraction rates of the corresponding cardiac cell monolayers were 40% higher at p(O2) of 160 than 60 mm Hg. The control of oxygen concentration in cell microenvironment can thus improve the structure and function of engineered cardiac muscle. Experiments of this kind can form a basis for controlled studies of the effects of oxygen on the in vitro development of engineered tissues.

show abstract

Section: Discussioncontrasting

confidence: 55%

Effects of oxygen on engineered cardiac muscle

Rupnick

Langer

Schoen

et al. 2002

Biotech & Bioengineering

130

View full text Add to dashboard Cite

show abstract

“…In the native heart, cardiomyocytes are shielded from direct contact with blood by endothelial cells. When exposed to excessive shear stress cardiomyocytes become rounded and show signs of de‐differentiation 27–31. Recent studies with neonatal cardiomyocytes cultivated in porous alginate scaffolds indicate that the application of interstitial flow at shear stresses higher than 2.4 dyn/cm 2 resulted in p38 activation and initiation of apoptosis 5.…”

Section: Resultsmentioning

confidence: 99%

Pulsatile perfusion bioreactor for cardiac tissue engineering

Brown

Iyer

Radišić

2008

Biotechnology Progress

View full text Add to dashboard Cite

Cardiovascular disease is the number one cause of mortality in North America. Cardiac tissue engineering aims to engineer a contractile patch of physiological thickness to use in surgical repair of diseased heart tissue. We previously reported that perfusion of engineered cardiac constructs resulted in improved tissue assembly. Because heart tissues respond to mechanical stimuli in vitro and experience rhythmic mechanical forces during contraction in vivo, we hypothesized that provision of pulsatile interstitial medium flow to an engineered cardiac patch would result in enhanced tissue assembly by way of mechanical conditioning and improved mass transport. Thus, we constructed a novel perfusion bioreactor capable of providing pulsatile fluid flow at physiologically relevant shear stresses and flow rates. Pulsatile perfusion (PP) was achieved by incorporation of a normally closed solenoid pinch valve into the perfusion loop and was carried out at a frequency of 1 Hz and a flow rate of 1.50 mL/min (PP) or 0.32 mL/min (PP-LF). Nonpulsatile flow at 1.50 mL/min (NP) or 0.32 mL/min (NP-LF) served as controls. Static controls were cultivated in well plates. The main experimental groups were seeded with cells enriched for cardiomyocytes by one preplating step (64% cardiac Troponin I+, 34% prolyl-4-hydroxylase+), whereas pure cardiac fibroblasts and cells enriched for cardiomyocytes by two preplating steps (81% cardiac Troponin I+, 16% prolyl-4-hydroxylase+) served as controls. Cultivation under pulsatile flow had beneficial effects on contractile properties. Specifically, the excitation threshold was significantly lower in the PP condition (pulsatile perfusion at 1.50 mL/min) than in the Static control, and the contraction amplitude was the highest; whereas high maximum capture rate was observed for the PP-LF conditions (pulsatile perfusion at 0.32 mL/min). The enhanced hypertrophy index observed for the PP-LF group was consistent with the highest cellular length and diameter in this group. Within the same cultivation groups (Static, NP-LF, PP-LF, PP, and NP) there were no significant differences in the diameter between fibroblasts and cardiomyocytes, although cardiomyocytes were significantly more elongated than fibroblasts under PP-LF conditions. Cultivation of control cell populations resulted in noncontractile constructs when cardiac fibroblasts were used (as expected) and no overall improvement in functional properties when two steps of preplating were used to enrich for cardiomyocytes in comparison with only one step of preplating.

show abstract

“…22 )) have detrimental effects on cardiac cells including cell death and apoptosis. When exposed to excessive shear stress, CMs round up and show signs of dedifferentiation 5,6,[23][24][25] .…”

Section: Selecting Culture Parametersmentioning

confidence: 99%

Cardiac tissue engineering using perfusion bioreactor systems

et al. 2008

View full text Add to dashboard Cite

This protocol describes tissue engineering of synchronously contractile cardiac constructs by culturing cardiac cell populations on porous scaffolds (in some cases with an array of channels) and bioreactors with perfusion of culture medium (in some cases supplemented with an oxygen carrier). The overall approach is 'biomimetic' in nature as it tends to provide in vivo-like oxygen supply to cultured cells and thereby overcome inherent limitations of diffusional transport in conventional culture systems. In order to mimic the capillary network, cells are cultured on channeled elastomer scaffolds that are perfused with culture medium that can contain oxygen carriers. The overall protocol takes 2-4 weeks, including assembly of the perfusion systems, preparation of scaffolds, cell seeding and cultivation, and on-line and end-point assessment methods. This model is well suited for a wide range of cardiac tissue engineering applications, including the use of human stem cells, and highfidelity models for biological research.

show abstract

Shear sensitivity of three hybridoma cell lines in suspension culture

Cited by 11 publications

References 7 publications

Effects of oxygen on engineered cardiac muscle

Effects of oxygen on engineered cardiac muscle

Pulsatile perfusion bioreactor for cardiac tissue engineering

Cardiac tissue engineering using perfusion bioreactor systems

Contact Info

Product

Resources

About