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Transient mild hyperthermia induces E-selectin mediated localization of mesoporous silicon vectors in solid tumors.

Kirui DK, Mai J, Palange AL, Qin G, van de Ven AL, Liu X, Shen H, Ferrari M - PLoS ONE (2014)

Bottom Line: We also determined the optimal time window at which maximal accumulation occur.By flow chamber experiments and Western blotting, we established that a temporal increase in E-selectin expression correlated with enhanced particle accumulation.Such enhancement in accumulation could be leveraged to increase therapeutic efficacy and reduce drug dosing in cancer therapy.

View Article: PubMed Central - PubMed

Affiliation: Department of NanoMedicine, Houston Methodist Research Institute, Houston, Texas, United States of America.

ABSTRACT

Background: Hyperthermia treatment has been explored as a strategy to overcome biological barriers that hinder effective drug delivery in solid tumors. Most studies have used mild hyperthermia treatment (MHT) to target the delivery of thermo-sensitive liposomes carriers. Others have studied its application to permeabilize tumor vessels and improve tumor interstitial transport. However, the role of MHT in altering tumor vessel interfacial and adhesion properties and its relationship to improved delivery has not been established. In the present study, we evaluated effects of MHT treatment on tumor vessel flow dynamics and expression of adhesion molecules and assessed enhancement in particle localization using mesoporous silicon vectors (MSVs). We also determined the optimal time window at which maximal accumulation occur.

Results: In this study, using intravital microscopy analyses, we showed that temporal mild hyperthermia (∼1 W/cm(2)) amplified delivery and accumulation of MSVs in orthotopic breast cancer tumors. The number of discoidal MSVs (1000×400 nm) adhering to tumor vasculature increased 6-fold for SUM159 tumors and 3-fold for MCF-7 breast cancer tumors. By flow chamber experiments and Western blotting, we established that a temporal increase in E-selectin expression correlated with enhanced particle accumulation. Furthermore, MHT treatment was shown to increase tumor perfusion in a time-dependent fashion.

Conclusions: Our findings reveal that well-timed mild hyperthermia treatment can transiently elevate tumor transport and alter vascular adhesion properties and thereby provides a means to enhance tumor localization of non-thermally sensitive particles such as MSVs. Such enhancement in accumulation could be leveraged to increase therapeutic efficacy and reduce drug dosing in cancer therapy.

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Flow chamber experimentation revealed increased particle-endothelial cell interactions after MHT treatment.A) representative images demonstrate extent of particle-HUVEC cells binding without treatment (top panel); at 5 h, the number of MSVs attached to HUVECs is significantly increased relative to control but the effect was negated upon incubation with anti-E-selectin; at 24 h, MSV binding is significant compared to control and incubation with anti-ICAM-1 slightly reduced binding while anti-E-selectin caused in insignificant reduced; B) Quantitative analyses demonstrating significant increase in particle adhesion to HUVECs cells with highest increase occurring at 5 h. Pre-incubation with anti-E-selectin reduced cell binding to almost basal levels. MSVs are fluorescent labeled (red) with Alexa Fluor 555 in which video and images are acquired with x20 objective lens. Error bars represent s.d. in 30 field of views (3.2×3.2 mm) from n = 3, with statistical significance denoted by * p<0.021, ** p<0.016, and *** p<0.009.
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pone-0086489-g006: Flow chamber experimentation revealed increased particle-endothelial cell interactions after MHT treatment.A) representative images demonstrate extent of particle-HUVEC cells binding without treatment (top panel); at 5 h, the number of MSVs attached to HUVECs is significantly increased relative to control but the effect was negated upon incubation with anti-E-selectin; at 24 h, MSV binding is significant compared to control and incubation with anti-ICAM-1 slightly reduced binding while anti-E-selectin caused in insignificant reduced; B) Quantitative analyses demonstrating significant increase in particle adhesion to HUVECs cells with highest increase occurring at 5 h. Pre-incubation with anti-E-selectin reduced cell binding to almost basal levels. MSVs are fluorescent labeled (red) with Alexa Fluor 555 in which video and images are acquired with x20 objective lens. Error bars represent s.d. in 30 field of views (3.2×3.2 mm) from n = 3, with statistical significance denoted by * p<0.021, ** p<0.016, and *** p<0.009.

Mentions: We observed that localized MHT treatment increased MSVs accumulation that were primarily lodged on tumor vasculature in low- and well-vascularized tumors, and therefore hypothesized that hyperthermia increases particle-endothelial cell interfacial interactions. In the next set of experiments, we evaluated the interactions between HUVEC cells and MSVs in flow chamber experiments. Endothelial cells grown on fibronectin-coated cover slips were used to study their interaction with MSVs at different time-points after MHT treatment. Figure 6 A show representative images of MSVs (red) attached to the monolayer of endothelial cells at the end of flow experiments. At 1 h after MHT treatment, HUVEC cell-particle interaction remained relatively unchanged as evidenced by slight and insignificant increase in MSV attachment. However, cell-MSVs interactions were maximal at 5 h after treatment, with the highest number of MSVs attaching to HUVEC monolayer. Upon incubation with anti-E-selectin, this effect was almost completely negated while similar treatment with anti-ICAM-1 had minimal effect on particle binding (Figure 6 A). This result suggested that E-selectin plays a role in anchoring MSV particles onto the endothelial lining during flow. At 24 h after MHT, the number of adherent MSVs were reduced compared to enhancements at 5 h (Figure 6 A, (w/o)). Incubation with anti-E-selectin, conversely, did not alter the number of attached MSVs while incubation with anti-ICAM-1 slightly reduced the extent of MSV attachment (Figure 6 A). Quantitative analyses of adherent MSVs over ∼30 FOVs are shown in Figure 6 B. MHT treatment statistically increased the number of adherent MSVs at 5 h time-point while pre-treatment with anti-E-selectin negated this effect. Enhancement obtained from MHT treatment appeared to abate at 24 h where reduction in the number of enumerated MSVs is notable. The effect of anti-ICAM-1 treatment is more pronounced than effect of anti-E-selectin at the 24 h time-point (Figure 6 B). These experiments correlated increased particle-HUVEC cell association to elevated expression of E-selectin adhesion molecules caused by MHT treatment. It demonstrates that MHT heat stimulation can positively affect particle-cell interaction by induction of vascular-associated adhesion molecules that can mediate particle associations along vessel walls.


Transient mild hyperthermia induces E-selectin mediated localization of mesoporous silicon vectors in solid tumors.

Kirui DK, Mai J, Palange AL, Qin G, van de Ven AL, Liu X, Shen H, Ferrari M - PLoS ONE (2014)

Flow chamber experimentation revealed increased particle-endothelial cell interactions after MHT treatment.A) representative images demonstrate extent of particle-HUVEC cells binding without treatment (top panel); at 5 h, the number of MSVs attached to HUVECs is significantly increased relative to control but the effect was negated upon incubation with anti-E-selectin; at 24 h, MSV binding is significant compared to control and incubation with anti-ICAM-1 slightly reduced binding while anti-E-selectin caused in insignificant reduced; B) Quantitative analyses demonstrating significant increase in particle adhesion to HUVECs cells with highest increase occurring at 5 h. Pre-incubation with anti-E-selectin reduced cell binding to almost basal levels. MSVs are fluorescent labeled (red) with Alexa Fluor 555 in which video and images are acquired with x20 objective lens. Error bars represent s.d. in 30 field of views (3.2×3.2 mm) from n = 3, with statistical significance denoted by * p<0.021, ** p<0.016, and *** p<0.009.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC3928046&req=5

pone-0086489-g006: Flow chamber experimentation revealed increased particle-endothelial cell interactions after MHT treatment.A) representative images demonstrate extent of particle-HUVEC cells binding without treatment (top panel); at 5 h, the number of MSVs attached to HUVECs is significantly increased relative to control but the effect was negated upon incubation with anti-E-selectin; at 24 h, MSV binding is significant compared to control and incubation with anti-ICAM-1 slightly reduced binding while anti-E-selectin caused in insignificant reduced; B) Quantitative analyses demonstrating significant increase in particle adhesion to HUVECs cells with highest increase occurring at 5 h. Pre-incubation with anti-E-selectin reduced cell binding to almost basal levels. MSVs are fluorescent labeled (red) with Alexa Fluor 555 in which video and images are acquired with x20 objective lens. Error bars represent s.d. in 30 field of views (3.2×3.2 mm) from n = 3, with statistical significance denoted by * p<0.021, ** p<0.016, and *** p<0.009.
Mentions: We observed that localized MHT treatment increased MSVs accumulation that were primarily lodged on tumor vasculature in low- and well-vascularized tumors, and therefore hypothesized that hyperthermia increases particle-endothelial cell interfacial interactions. In the next set of experiments, we evaluated the interactions between HUVEC cells and MSVs in flow chamber experiments. Endothelial cells grown on fibronectin-coated cover slips were used to study their interaction with MSVs at different time-points after MHT treatment. Figure 6 A show representative images of MSVs (red) attached to the monolayer of endothelial cells at the end of flow experiments. At 1 h after MHT treatment, HUVEC cell-particle interaction remained relatively unchanged as evidenced by slight and insignificant increase in MSV attachment. However, cell-MSVs interactions were maximal at 5 h after treatment, with the highest number of MSVs attaching to HUVEC monolayer. Upon incubation with anti-E-selectin, this effect was almost completely negated while similar treatment with anti-ICAM-1 had minimal effect on particle binding (Figure 6 A). This result suggested that E-selectin plays a role in anchoring MSV particles onto the endothelial lining during flow. At 24 h after MHT, the number of adherent MSVs were reduced compared to enhancements at 5 h (Figure 6 A, (w/o)). Incubation with anti-E-selectin, conversely, did not alter the number of attached MSVs while incubation with anti-ICAM-1 slightly reduced the extent of MSV attachment (Figure 6 A). Quantitative analyses of adherent MSVs over ∼30 FOVs are shown in Figure 6 B. MHT treatment statistically increased the number of adherent MSVs at 5 h time-point while pre-treatment with anti-E-selectin negated this effect. Enhancement obtained from MHT treatment appeared to abate at 24 h where reduction in the number of enumerated MSVs is notable. The effect of anti-ICAM-1 treatment is more pronounced than effect of anti-E-selectin at the 24 h time-point (Figure 6 B). These experiments correlated increased particle-HUVEC cell association to elevated expression of E-selectin adhesion molecules caused by MHT treatment. It demonstrates that MHT heat stimulation can positively affect particle-cell interaction by induction of vascular-associated adhesion molecules that can mediate particle associations along vessel walls.

Bottom Line: We also determined the optimal time window at which maximal accumulation occur.By flow chamber experiments and Western blotting, we established that a temporal increase in E-selectin expression correlated with enhanced particle accumulation.Such enhancement in accumulation could be leveraged to increase therapeutic efficacy and reduce drug dosing in cancer therapy.

View Article: PubMed Central - PubMed

Affiliation: Department of NanoMedicine, Houston Methodist Research Institute, Houston, Texas, United States of America.

ABSTRACT

Background: Hyperthermia treatment has been explored as a strategy to overcome biological barriers that hinder effective drug delivery in solid tumors. Most studies have used mild hyperthermia treatment (MHT) to target the delivery of thermo-sensitive liposomes carriers. Others have studied its application to permeabilize tumor vessels and improve tumor interstitial transport. However, the role of MHT in altering tumor vessel interfacial and adhesion properties and its relationship to improved delivery has not been established. In the present study, we evaluated effects of MHT treatment on tumor vessel flow dynamics and expression of adhesion molecules and assessed enhancement in particle localization using mesoporous silicon vectors (MSVs). We also determined the optimal time window at which maximal accumulation occur.

Results: In this study, using intravital microscopy analyses, we showed that temporal mild hyperthermia (∼1 W/cm(2)) amplified delivery and accumulation of MSVs in orthotopic breast cancer tumors. The number of discoidal MSVs (1000×400 nm) adhering to tumor vasculature increased 6-fold for SUM159 tumors and 3-fold for MCF-7 breast cancer tumors. By flow chamber experiments and Western blotting, we established that a temporal increase in E-selectin expression correlated with enhanced particle accumulation. Furthermore, MHT treatment was shown to increase tumor perfusion in a time-dependent fashion.

Conclusions: Our findings reveal that well-timed mild hyperthermia treatment can transiently elevate tumor transport and alter vascular adhesion properties and thereby provides a means to enhance tumor localization of non-thermally sensitive particles such as MSVs. Such enhancement in accumulation could be leveraged to increase therapeutic efficacy and reduce drug dosing in cancer therapy.

Show MeSH
Related in: MedlinePlus