Limits...
Investigation of Fatty Acid Ketohydrazone Modified Liposome's Properties as a Drug Carrier.

Hayashi K, Kiriishi M, Suga K, Okamoto Y, Umakoshi H - J Drug Deliv (2015)

Bottom Line: The interface of the P-KH modified liposome at acidic pH was found to become more hydrophobic and less fluidic as compared with that at neutral pH; that is, P-KH modified liposome became more rigid structure.Therefore, it seems that the P-KH modified liposome could protect encapsulated drugs from the enzymes in the lysosome.This study shows the novel approach about design of pH-responsive liposomes based on the membrane properties.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical Engineering, National Institute of Technology, Nara College, 22 Yata-cho, Yamatokoriyama, Nara 639-1080, Japan.

ABSTRACT
pH-responsive liposomes were prepared by modifying the liposome with acid-cleaving amphiphiles. Palmitic ketohydrazone (P-KH) or stearic ketohydrazone (S-KH), composed of hydrophilic sugar headgroup and hydrophobic acyl chain, was used as a modifier of the DMPC liposome. Because the ketohydrazone group of P-KH or S-KH was cleaved at low pH conditions (

No MeSH data available.


Related in: MedlinePlus

Alteration of membrane properties with dropping pH. Membrane properties were evaluated by membrane fluidity (1/P, anisotropy of DPH fluorescence) and hydrophilic/hydrophobic environment (GP(340) values calculated by Laurdan fluorescence intensity) of liposomal membrane. 2~4 and 5~7 show the physicochemical properties of P-KH liposome and S-KH liposome in PBS, and 2′~4′ and 5′~7′ show that of P-KH liposome and S-KH liposome at pH 5.0.
© Copyright Policy - open-access
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4663332&req=5

fig5: Alteration of membrane properties with dropping pH. Membrane properties were evaluated by membrane fluidity (1/P, anisotropy of DPH fluorescence) and hydrophilic/hydrophobic environment (GP(340) values calculated by Laurdan fluorescence intensity) of liposomal membrane. 2~4 and 5~7 show the physicochemical properties of P-KH liposome and S-KH liposome in PBS, and 2′~4′ and 5′~7′ show that of P-KH liposome and S-KH liposome at pH 5.0.

Mentions: Figure 5 shows pH dependence of the membrane fluidity (1/P value) and hydrophilic/hydrophobic environment (membrane polarity, GP(340) value) of the liposomes. The 1/P values of P-KH liposomes decreased at pH 5, while the GP(340) values of P-KH liposomes increased at pH 5. It has been reported that a hydrazone bond is stable at pH ~7, and it turns out to be cleaved at lower pH less than 5 [22]. Therefore, P-KH was assumed to be cleaved to C-glycoside ketone and palmitic acid hydrazide at pH 5, where the P-KH molecules on the liposomes can be partly altered to palmitic acid. The variation of the P-KH composition on the liposome membrane could induce the alteration of the membrane properties during the pH shift. This type of pH shift is, in general, observed inside the cell during its endocytotic pathway. Although the membrane properties of S-KH liposome did not show significant alteration by pH gradient, it is notable that the membrane fluidities of liposomes increased by modification both with P-KH and with S-KH.


Investigation of Fatty Acid Ketohydrazone Modified Liposome's Properties as a Drug Carrier.

Hayashi K, Kiriishi M, Suga K, Okamoto Y, Umakoshi H - J Drug Deliv (2015)

Alteration of membrane properties with dropping pH. Membrane properties were evaluated by membrane fluidity (1/P, anisotropy of DPH fluorescence) and hydrophilic/hydrophobic environment (GP(340) values calculated by Laurdan fluorescence intensity) of liposomal membrane. 2~4 and 5~7 show the physicochemical properties of P-KH liposome and S-KH liposome in PBS, and 2′~4′ and 5′~7′ show that of P-KH liposome and S-KH liposome at pH 5.0.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4663332&req=5

fig5: Alteration of membrane properties with dropping pH. Membrane properties were evaluated by membrane fluidity (1/P, anisotropy of DPH fluorescence) and hydrophilic/hydrophobic environment (GP(340) values calculated by Laurdan fluorescence intensity) of liposomal membrane. 2~4 and 5~7 show the physicochemical properties of P-KH liposome and S-KH liposome in PBS, and 2′~4′ and 5′~7′ show that of P-KH liposome and S-KH liposome at pH 5.0.
Mentions: Figure 5 shows pH dependence of the membrane fluidity (1/P value) and hydrophilic/hydrophobic environment (membrane polarity, GP(340) value) of the liposomes. The 1/P values of P-KH liposomes decreased at pH 5, while the GP(340) values of P-KH liposomes increased at pH 5. It has been reported that a hydrazone bond is stable at pH ~7, and it turns out to be cleaved at lower pH less than 5 [22]. Therefore, P-KH was assumed to be cleaved to C-glycoside ketone and palmitic acid hydrazide at pH 5, where the P-KH molecules on the liposomes can be partly altered to palmitic acid. The variation of the P-KH composition on the liposome membrane could induce the alteration of the membrane properties during the pH shift. This type of pH shift is, in general, observed inside the cell during its endocytotic pathway. Although the membrane properties of S-KH liposome did not show significant alteration by pH gradient, it is notable that the membrane fluidities of liposomes increased by modification both with P-KH and with S-KH.

Bottom Line: The interface of the P-KH modified liposome at acidic pH was found to become more hydrophobic and less fluidic as compared with that at neutral pH; that is, P-KH modified liposome became more rigid structure.Therefore, it seems that the P-KH modified liposome could protect encapsulated drugs from the enzymes in the lysosome.This study shows the novel approach about design of pH-responsive liposomes based on the membrane properties.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical Engineering, National Institute of Technology, Nara College, 22 Yata-cho, Yamatokoriyama, Nara 639-1080, Japan.

ABSTRACT
pH-responsive liposomes were prepared by modifying the liposome with acid-cleaving amphiphiles. Palmitic ketohydrazone (P-KH) or stearic ketohydrazone (S-KH), composed of hydrophilic sugar headgroup and hydrophobic acyl chain, was used as a modifier of the DMPC liposome. Because the ketohydrazone group of P-KH or S-KH was cleaved at low pH conditions (

No MeSH data available.


Related in: MedlinePlus