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Predicting in vivo efficacy of potential restenosis therapies by cell culture studies: species-dependent susceptibility of vascular smooth muscle cells.

Epstein H, Rabinovich L, Banai S, Elazar V, Gao J, Chorny M, Danenebrg HD, Golomb G - Open Cardiovasc Med J (2008)

Bottom Line: Elucidation of different species sensitivity (rat, rabbit, porcine and human) to diverse drugs (tyrphostins, heparin and bisphsophonates) and a delivery system (nanoparticles) could provide a valuable screening tool for further in vivo studies.The anticipated sensitivity ranking from the explant outgrowth model and SMC mitotic rates (porcine>rat>rabbit>human) do not correlate with the observed relative sensitivity of those animals to antiproliferative therapy in restenosis models (rat>/=rabbit>porcine>human).Similarly, the inhibitory profile of the various antirestenotic drugs in SMC cultures (rabbit>porcine>rat>human) do not correlate with animal studies, the rabbit- and porcine-derived SMC being highly sensitive.

View Article: PubMed Central - PubMed

Affiliation: Dept. of Pharmaceutics, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem 91120, Israel.

ABSTRACT
Although drug-eluting stents (DES) are successfully utilized for restenosis therapy, the development of local and systemic therapeutic means including nanoparticles (NP) continues. Lack of correlation between in vitro and in vivo studies is one of the major drawbacks in developing new drug delivery systems. The present study was designed to examine the applicability of the arterial explant outgrowth model, and of smooth muscle cells (SMC) cultures for prescreening of possible drugs. Elucidation of different species sensitivity (rat, rabbit, porcine and human) to diverse drugs (tyrphostins, heparin and bisphsophonates) and a delivery system (nanoparticles) could provide a valuable screening tool for further in vivo studies. The anticipated sensitivity ranking from the explant outgrowth model and SMC mitotic rates (porcine>rat>rabbit>human) do not correlate with the observed relative sensitivity of those animals to antiproliferative therapy in restenosis models (rat>/=rabbit>porcine>human). Similarly, the inhibitory profile of the various antirestenotic drugs in SMC cultures (rabbit>porcine>rat>human) do not correlate with animal studies, the rabbit- and porcine-derived SMC being highly sensitive. The validity of in vitro culture studies for the screening of controlled release delivery systems such as nanoparticles is limited. It is suggested that prescreening studies of possible drug candidates for restenosis therapy should include both SMC cell cultures of rat and human, appropriately designed with a suitable serum.

No MeSH data available.


Related in: MedlinePlus

Uptake of SMC from various species (rat, rabbit, and human) incubated with fluorescently labeled PLGA-NP (Rhodamine) 24hr following treatment. a) Confocal cross-section images of SMC incubated with fluorescent NP. Note the uptake of NP, and the extensive internalization by human SMC. The NP were localized in the cytoplasm. b) Fluorescence intensity histogram of SMC detemined by FACS following application of fluorescent-labeled PLGA-NP with Rhodamin, and PLA-NP with BODIPY, 24hr after incubation. Note that intensity was higher in all species for PLGA-NP (pink) than PLA-NP (green), with extensive uptake of PLGA-NP in human SMC (60%) in comparison to 20% and 10%, rat and rabbit SMC, respectively.
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Figure 8: Uptake of SMC from various species (rat, rabbit, and human) incubated with fluorescently labeled PLGA-NP (Rhodamine) 24hr following treatment. a) Confocal cross-section images of SMC incubated with fluorescent NP. Note the uptake of NP, and the extensive internalization by human SMC. The NP were localized in the cytoplasm. b) Fluorescence intensity histogram of SMC detemined by FACS following application of fluorescent-labeled PLGA-NP with Rhodamin, and PLA-NP with BODIPY, 24hr after incubation. Note that intensity was higher in all species for PLGA-NP (pink) than PLA-NP (green), with extensive uptake of PLGA-NP in human SMC (60%) in comparison to 20% and 10%, rat and rabbit SMC, respectively.

Mentions: In order to elucidate whether cell sensitivity is related to the different capability of the various species' SMC to internalize NP, fluorescent NP were utilized for assessing internalization. Non-labeled particles exhibited a very low fluorescent signal and were determined as background for further analyses. Confocal microscopy cross-sections verified cell internalization and the NP were localized in the cytoplasm 24hr following incubation of fluorescent-labeled PLGA-NP (Fig. 8a). Similar experiments were carried out with PLA-NP (encapsulating tyrphostins), and a lower extent of internalization was observed in comparison to PLGA-NP (encapsulating bisphosphonates). Quantification of the uptake was determined by FACS analysis. The highest uptake of particles was observed in human SMC up to a total of 60% of the cells, and to a lower extent in SMC of rat and rabbit, 30% and 10%, respectively (Fig. 8b). The higher internalization capacity of PLGA-NP in comparison to PLA-NP was observed in all species. The ranking of uptake between the various cell species was determined as, human>rat>rabbit.


Predicting in vivo efficacy of potential restenosis therapies by cell culture studies: species-dependent susceptibility of vascular smooth muscle cells.

Epstein H, Rabinovich L, Banai S, Elazar V, Gao J, Chorny M, Danenebrg HD, Golomb G - Open Cardiovasc Med J (2008)

Uptake of SMC from various species (rat, rabbit, and human) incubated with fluorescently labeled PLGA-NP (Rhodamine) 24hr following treatment. a) Confocal cross-section images of SMC incubated with fluorescent NP. Note the uptake of NP, and the extensive internalization by human SMC. The NP were localized in the cytoplasm. b) Fluorescence intensity histogram of SMC detemined by FACS following application of fluorescent-labeled PLGA-NP with Rhodamin, and PLA-NP with BODIPY, 24hr after incubation. Note that intensity was higher in all species for PLGA-NP (pink) than PLA-NP (green), with extensive uptake of PLGA-NP in human SMC (60%) in comparison to 20% and 10%, rat and rabbit SMC, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2570571&req=5

Figure 8: Uptake of SMC from various species (rat, rabbit, and human) incubated with fluorescently labeled PLGA-NP (Rhodamine) 24hr following treatment. a) Confocal cross-section images of SMC incubated with fluorescent NP. Note the uptake of NP, and the extensive internalization by human SMC. The NP were localized in the cytoplasm. b) Fluorescence intensity histogram of SMC detemined by FACS following application of fluorescent-labeled PLGA-NP with Rhodamin, and PLA-NP with BODIPY, 24hr after incubation. Note that intensity was higher in all species for PLGA-NP (pink) than PLA-NP (green), with extensive uptake of PLGA-NP in human SMC (60%) in comparison to 20% and 10%, rat and rabbit SMC, respectively.
Mentions: In order to elucidate whether cell sensitivity is related to the different capability of the various species' SMC to internalize NP, fluorescent NP were utilized for assessing internalization. Non-labeled particles exhibited a very low fluorescent signal and were determined as background for further analyses. Confocal microscopy cross-sections verified cell internalization and the NP were localized in the cytoplasm 24hr following incubation of fluorescent-labeled PLGA-NP (Fig. 8a). Similar experiments were carried out with PLA-NP (encapsulating tyrphostins), and a lower extent of internalization was observed in comparison to PLGA-NP (encapsulating bisphosphonates). Quantification of the uptake was determined by FACS analysis. The highest uptake of particles was observed in human SMC up to a total of 60% of the cells, and to a lower extent in SMC of rat and rabbit, 30% and 10%, respectively (Fig. 8b). The higher internalization capacity of PLGA-NP in comparison to PLA-NP was observed in all species. The ranking of uptake between the various cell species was determined as, human>rat>rabbit.

Bottom Line: Elucidation of different species sensitivity (rat, rabbit, porcine and human) to diverse drugs (tyrphostins, heparin and bisphsophonates) and a delivery system (nanoparticles) could provide a valuable screening tool for further in vivo studies.The anticipated sensitivity ranking from the explant outgrowth model and SMC mitotic rates (porcine>rat>rabbit>human) do not correlate with the observed relative sensitivity of those animals to antiproliferative therapy in restenosis models (rat>/=rabbit>porcine>human).Similarly, the inhibitory profile of the various antirestenotic drugs in SMC cultures (rabbit>porcine>rat>human) do not correlate with animal studies, the rabbit- and porcine-derived SMC being highly sensitive.

View Article: PubMed Central - PubMed

Affiliation: Dept. of Pharmaceutics, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem 91120, Israel.

ABSTRACT
Although drug-eluting stents (DES) are successfully utilized for restenosis therapy, the development of local and systemic therapeutic means including nanoparticles (NP) continues. Lack of correlation between in vitro and in vivo studies is one of the major drawbacks in developing new drug delivery systems. The present study was designed to examine the applicability of the arterial explant outgrowth model, and of smooth muscle cells (SMC) cultures for prescreening of possible drugs. Elucidation of different species sensitivity (rat, rabbit, porcine and human) to diverse drugs (tyrphostins, heparin and bisphsophonates) and a delivery system (nanoparticles) could provide a valuable screening tool for further in vivo studies. The anticipated sensitivity ranking from the explant outgrowth model and SMC mitotic rates (porcine>rat>rabbit>human) do not correlate with the observed relative sensitivity of those animals to antiproliferative therapy in restenosis models (rat>/=rabbit>porcine>human). Similarly, the inhibitory profile of the various antirestenotic drugs in SMC cultures (rabbit>porcine>rat>human) do not correlate with animal studies, the rabbit- and porcine-derived SMC being highly sensitive. The validity of in vitro culture studies for the screening of controlled release delivery systems such as nanoparticles is limited. It is suggested that prescreening studies of possible drug candidates for restenosis therapy should include both SMC cell cultures of rat and human, appropriately designed with a suitable serum.

No MeSH data available.


Related in: MedlinePlus