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BSA Nanoparticles for siRNA Delivery: Coating Effects on Nanoparticle Properties, Plasma Protein Adsorption, and In Vitro siRNA Delivery.

Yogasundaram H, Bahniuk MS, Singh HD, Aliabadi HM, Uludağ H, Unsworth LD - Int J Biomater (2012)

Bottom Line: PEGylated PLL coatings resulted in NPs with ζ-potentials close to neutral.Incubation with platelet-poor plasma showed the composition of the adsorbed proteome was similar for all systems. siRNA was effectively encapsulated and released in a sustained manner from all NPs.The overall results identified a BSA-NP coating structure that provided effective siRNA encapsulation while reducing ζ-potential, protein adsorption, and cytotoxicity, necessary attributes for in vivo application of drug-delivery vehicles.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical and Materials Engineering, Faculty of Engineering, University of Alberta, Edmonton, AB, Canada T6G 2G6.

ABSTRACT
Developing vehicles for the delivery of therapeutic molecules, like siRNA, is an area of active research. Nanoparticles composed of bovine serum albumin, stabilized via the adsorption of poly-L-lysine (PLL), have been shown to be potentially inert drug-delivery vehicles. With the primary goal of reducing nonspecific protein adsorption, the effect of using comb-type structures of poly(ethylene glycol) (1 kDa, PEG) units conjugated to PLL (4.2 and 24 kDa) on BSA-NP properties, apparent siRNA release rate, cell viability, and cell uptake were evaluated. PEGylated PLL coatings resulted in NPs with ζ-potentials close to neutral. Incubation with platelet-poor plasma showed the composition of the adsorbed proteome was similar for all systems. siRNA was effectively encapsulated and released in a sustained manner from all NPs. With 4.2 kDa PLL, cellular uptake was not affected by the presence of PEG, but PEG coating inhibited uptake with 24 kDa PLL NPs. Moreover, 24 kDa PLL systems were cytotoxic and this cytotoxicity was diminished upon PEG incorporation. The overall results identified a BSA-NP coating structure that provided effective siRNA encapsulation while reducing ζ-potential, protein adsorption, and cytotoxicity, necessary attributes for in vivo application of drug-delivery vehicles.

No MeSH data available.


Data summarizing the mean uptake and percent cellular uptake of labeled and unlabeled siRNA. (a) Mean (+1 SD) FAM fluorescence of the cells exposed to NPs without siRNA (□) and with siRNA (■). BSA NPs coated with 24 kDa PLL showed the greatest cellular uptake. (b) Mean (+1 SD) siRNA-positive cells when the cells were exposed to NPs without siRNA (□) and with siRNA (■). BSA NPs coated with 24 kDa PLL showed the greatest value of siRNA-positive cell population. The value in parentheses represents the molecular weight of the PLL in kDa.
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fig4: Data summarizing the mean uptake and percent cellular uptake of labeled and unlabeled siRNA. (a) Mean (+1 SD) FAM fluorescence of the cells exposed to NPs without siRNA (□) and with siRNA (■). BSA NPs coated with 24 kDa PLL showed the greatest cellular uptake. (b) Mean (+1 SD) siRNA-positive cells when the cells were exposed to NPs without siRNA (□) and with siRNA (■). BSA NPs coated with 24 kDa PLL showed the greatest value of siRNA-positive cell population. The value in parentheses represents the molecular weight of the PLL in kDa.

Mentions: The siRNA uptake is summarized in Figure 4 as the mean uptake (Figure 4(a)) or the percentage of cells positive for siRNA (Figure 4(b)). The mean fluorescence of the cells exposed to NPs without FAM-siRNA was not statistically different among the NPs (as expected), and represented the background readings (i.e., normal autofluorescence). Compared to uncoated NPs, cells exposed to coated NPs containing FAM-siRNA all had greater fluorescence than the background (P < 0.01 for NPs coated with 4 kDa PLL, 24 kDa PLL and 4 kDa PEG-PLL), except the NPs coated with 24 kDa PEG-PLL. The latter did not show any evidence of increased uptake based on mean fluorescence of the cells. Although it is unknown why modification of the 24 kDa PLL NPs with PEG resulted in an insignificant amount of uptake (compared to controls), it is possible that the large average diameter of ~800 nm may prohibit cellular uptake. It was clear that the NPs coated with 24 kDa PLL had the highest cellular delivery of FAM-labeled siRNA. This was consistent with toxicity results that indicated highest toxicity (i.e., cell interaction) with this type of NPs. While the presence of PEG did not affect uptake with 4.2 kDa PLL, an apparent dramatic effect of PEG was evident with the 24 kDa PLL. The protein-repellent properties of PEG presumably prevented binding to cell surfaces, which is critical for internalization and siRNA uptake. This result was also in line with toxicity results, where the cells displayed much more tolerance to 24 kDa PEG-PLL coated NPs.


BSA Nanoparticles for siRNA Delivery: Coating Effects on Nanoparticle Properties, Plasma Protein Adsorption, and In Vitro siRNA Delivery.

Yogasundaram H, Bahniuk MS, Singh HD, Aliabadi HM, Uludağ H, Unsworth LD - Int J Biomater (2012)

Data summarizing the mean uptake and percent cellular uptake of labeled and unlabeled siRNA. (a) Mean (+1 SD) FAM fluorescence of the cells exposed to NPs without siRNA (□) and with siRNA (■). BSA NPs coated with 24 kDa PLL showed the greatest cellular uptake. (b) Mean (+1 SD) siRNA-positive cells when the cells were exposed to NPs without siRNA (□) and with siRNA (■). BSA NPs coated with 24 kDa PLL showed the greatest value of siRNA-positive cell population. The value in parentheses represents the molecular weight of the PLL in kDa.
© Copyright Policy - open-access
Related In: Results  -  Collection

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fig4: Data summarizing the mean uptake and percent cellular uptake of labeled and unlabeled siRNA. (a) Mean (+1 SD) FAM fluorescence of the cells exposed to NPs without siRNA (□) and with siRNA (■). BSA NPs coated with 24 kDa PLL showed the greatest cellular uptake. (b) Mean (+1 SD) siRNA-positive cells when the cells were exposed to NPs without siRNA (□) and with siRNA (■). BSA NPs coated with 24 kDa PLL showed the greatest value of siRNA-positive cell population. The value in parentheses represents the molecular weight of the PLL in kDa.
Mentions: The siRNA uptake is summarized in Figure 4 as the mean uptake (Figure 4(a)) or the percentage of cells positive for siRNA (Figure 4(b)). The mean fluorescence of the cells exposed to NPs without FAM-siRNA was not statistically different among the NPs (as expected), and represented the background readings (i.e., normal autofluorescence). Compared to uncoated NPs, cells exposed to coated NPs containing FAM-siRNA all had greater fluorescence than the background (P < 0.01 for NPs coated with 4 kDa PLL, 24 kDa PLL and 4 kDa PEG-PLL), except the NPs coated with 24 kDa PEG-PLL. The latter did not show any evidence of increased uptake based on mean fluorescence of the cells. Although it is unknown why modification of the 24 kDa PLL NPs with PEG resulted in an insignificant amount of uptake (compared to controls), it is possible that the large average diameter of ~800 nm may prohibit cellular uptake. It was clear that the NPs coated with 24 kDa PLL had the highest cellular delivery of FAM-labeled siRNA. This was consistent with toxicity results that indicated highest toxicity (i.e., cell interaction) with this type of NPs. While the presence of PEG did not affect uptake with 4.2 kDa PLL, an apparent dramatic effect of PEG was evident with the 24 kDa PLL. The protein-repellent properties of PEG presumably prevented binding to cell surfaces, which is critical for internalization and siRNA uptake. This result was also in line with toxicity results, where the cells displayed much more tolerance to 24 kDa PEG-PLL coated NPs.

Bottom Line: PEGylated PLL coatings resulted in NPs with ζ-potentials close to neutral.Incubation with platelet-poor plasma showed the composition of the adsorbed proteome was similar for all systems. siRNA was effectively encapsulated and released in a sustained manner from all NPs.The overall results identified a BSA-NP coating structure that provided effective siRNA encapsulation while reducing ζ-potential, protein adsorption, and cytotoxicity, necessary attributes for in vivo application of drug-delivery vehicles.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical and Materials Engineering, Faculty of Engineering, University of Alberta, Edmonton, AB, Canada T6G 2G6.

ABSTRACT
Developing vehicles for the delivery of therapeutic molecules, like siRNA, is an area of active research. Nanoparticles composed of bovine serum albumin, stabilized via the adsorption of poly-L-lysine (PLL), have been shown to be potentially inert drug-delivery vehicles. With the primary goal of reducing nonspecific protein adsorption, the effect of using comb-type structures of poly(ethylene glycol) (1 kDa, PEG) units conjugated to PLL (4.2 and 24 kDa) on BSA-NP properties, apparent siRNA release rate, cell viability, and cell uptake were evaluated. PEGylated PLL coatings resulted in NPs with ζ-potentials close to neutral. Incubation with platelet-poor plasma showed the composition of the adsorbed proteome was similar for all systems. siRNA was effectively encapsulated and released in a sustained manner from all NPs. With 4.2 kDa PLL, cellular uptake was not affected by the presence of PEG, but PEG coating inhibited uptake with 24 kDa PLL NPs. Moreover, 24 kDa PLL systems were cytotoxic and this cytotoxicity was diminished upon PEG incorporation. The overall results identified a BSA-NP coating structure that provided effective siRNA encapsulation while reducing ζ-potential, protein adsorption, and cytotoxicity, necessary attributes for in vivo application of drug-delivery vehicles.

No MeSH data available.