Limits...
pH and temperature dual-sensitive liposome gel based on novel cleavable mPEG-Hz-CHEMS polymeric vaginal delivery system.

Chen D, Sun K, Mu H, Tang M, Liang R, Wang A, Zhou S, Sun H, Zhao F, Yao J, Liu W - Int J Nanomedicine (2012)

Bottom Line: A dual-sensitive liposome gel with a high encapsulation efficiency of arctigenin was formed and improved the solubility of arctigenin characterized by Fourier transform infrared spectroscopy and differential scanning calorimetry.In vitro drug release results indicated that dual-sensitive liposome gels showed constant release of arctigenin over 3 days, but showed sustained release of arctigenin in buffers at pH 7.4 and pH 9.0.This research has shed some light on a pH and temperature dual-sensitive liposome gel using a cleavable mPEG-Hz-CHEMS polymer for vaginal delivery.

View Article: PubMed Central - PubMed

Affiliation: School of Pharmacy, Yantai University, Yantai, People’s Republic of China.

ABSTRACT

Background: In this study, a pH and temperature dual-sensitive liposome gel based on a novel cleavable hydrazone-based pH-sensitive methoxy polyethylene glycol 2000-hydrazone-cholesteryl hemisuccinate (mPEG-Hz-CHEMS) polymer was used for vaginal administration.

Methods: The pH-sensitive, cleavable mPEG-Hz-CHEMS was designed as a modified pH-sensitive liposome that would selectively degrade under locally acidic vaginal conditions. The novel pH-sensitive liposome was engineered to form a thermogel at body temperature and to degrade in an acidic environment.

Results: A dual-sensitive liposome gel with a high encapsulation efficiency of arctigenin was formed and improved the solubility of arctigenin characterized by Fourier transform infrared spectroscopy and differential scanning calorimetry. The dual-sensitive liposome gel with a sol-gel transition at body temperature was degraded in a pH-dependent manner, and was stable for a long period of time at neutral and basic pH, but cleavable under acidic conditions (pH 5.0). Arctigenin encapsulated in a dual-sensitive liposome gel was more stable and less toxic than arctigenin loaded into pH-sensitive liposomes. In vitro drug release results indicated that dual-sensitive liposome gels showed constant release of arctigenin over 3 days, but showed sustained release of arctigenin in buffers at pH 7.4 and pH 9.0.

Conclusion: This research has shed some light on a pH and temperature dual-sensitive liposome gel using a cleavable mPEG-Hz-CHEMS polymer for vaginal delivery.

Show MeSH

Related in: MedlinePlus

Cytotoxicity of AC dual-sensitive gels.Notes: Data represent the mean ± SD (n = 6). *P < 0.05, compared with the free AC.Abbreviation: AC, arctigenin.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3368511&req=5

f8-ijn-7-2621: Cytotoxicity of AC dual-sensitive gels.Notes: Data represent the mean ± SD (n = 6). *P < 0.05, compared with the free AC.Abbreviation: AC, arctigenin.

Mentions: The cytotoxicity of free arctigenin and the formulated arctigenin was investigated in HEK293 cells using MTT assays (Figure 8). Liposome gel was prepared by mixing P407 and P188 as described earlier in this paper, and was diluted with phosphate-buffered saline (1:2 and 1:4, v/v), because polymer gels should be diluted with a proper dilution ratio or extracted in medium in the cytotoxicity tests of polymer gels.17 Cell viability (%) in the presence of free arctigenin, arctigenin-loaded pH-sensitive liposomes, arctigenin-loaded dual-sensitive liposome gel, diluted samples of arctigenin-loaded dual-sensitive liposome gel with phosphate-buffered saline (1:2 and 1:4, v/v), and phosphate-buffered saline alone were 46.8 ± 2.6, 68.8 ± 3.7, 58.2 ± 4.1, 72.1 ± 3.6, 78.5 ± 4.0, 73.6 ± 3.8, and 76.3 ± 3.4, respectively. Arctigenin encapsulated in pH-sensitive liposomes or arctigenin-loaded dual-sensitive liposome gel was less toxic than free arctigenin. Furthermore, the cell viability of diluted arctigenin-loaded dual-sensitive liposome gel (1:2 and 1:4, v/v) was higher than for the intact dual-sensitive liposome gel. The cytotoxicity of free arctigenin in diluted gels (1:4 in phosphate-buffered saline) was also lower than for free arctigenin. Intact liposome gel without dilution appears to be somewhat toxic compared with arctigenin loaded into liposomes due to oxygen deficiency produced by the thickness of the gels.


pH and temperature dual-sensitive liposome gel based on novel cleavable mPEG-Hz-CHEMS polymeric vaginal delivery system.

Chen D, Sun K, Mu H, Tang M, Liang R, Wang A, Zhou S, Sun H, Zhao F, Yao J, Liu W - Int J Nanomedicine (2012)

Cytotoxicity of AC dual-sensitive gels.Notes: Data represent the mean ± SD (n = 6). *P < 0.05, compared with the free AC.Abbreviation: AC, arctigenin.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3368511&req=5

f8-ijn-7-2621: Cytotoxicity of AC dual-sensitive gels.Notes: Data represent the mean ± SD (n = 6). *P < 0.05, compared with the free AC.Abbreviation: AC, arctigenin.
Mentions: The cytotoxicity of free arctigenin and the formulated arctigenin was investigated in HEK293 cells using MTT assays (Figure 8). Liposome gel was prepared by mixing P407 and P188 as described earlier in this paper, and was diluted with phosphate-buffered saline (1:2 and 1:4, v/v), because polymer gels should be diluted with a proper dilution ratio or extracted in medium in the cytotoxicity tests of polymer gels.17 Cell viability (%) in the presence of free arctigenin, arctigenin-loaded pH-sensitive liposomes, arctigenin-loaded dual-sensitive liposome gel, diluted samples of arctigenin-loaded dual-sensitive liposome gel with phosphate-buffered saline (1:2 and 1:4, v/v), and phosphate-buffered saline alone were 46.8 ± 2.6, 68.8 ± 3.7, 58.2 ± 4.1, 72.1 ± 3.6, 78.5 ± 4.0, 73.6 ± 3.8, and 76.3 ± 3.4, respectively. Arctigenin encapsulated in pH-sensitive liposomes or arctigenin-loaded dual-sensitive liposome gel was less toxic than free arctigenin. Furthermore, the cell viability of diluted arctigenin-loaded dual-sensitive liposome gel (1:2 and 1:4, v/v) was higher than for the intact dual-sensitive liposome gel. The cytotoxicity of free arctigenin in diluted gels (1:4 in phosphate-buffered saline) was also lower than for free arctigenin. Intact liposome gel without dilution appears to be somewhat toxic compared with arctigenin loaded into liposomes due to oxygen deficiency produced by the thickness of the gels.

Bottom Line: A dual-sensitive liposome gel with a high encapsulation efficiency of arctigenin was formed and improved the solubility of arctigenin characterized by Fourier transform infrared spectroscopy and differential scanning calorimetry.In vitro drug release results indicated that dual-sensitive liposome gels showed constant release of arctigenin over 3 days, but showed sustained release of arctigenin in buffers at pH 7.4 and pH 9.0.This research has shed some light on a pH and temperature dual-sensitive liposome gel using a cleavable mPEG-Hz-CHEMS polymer for vaginal delivery.

View Article: PubMed Central - PubMed

Affiliation: School of Pharmacy, Yantai University, Yantai, People’s Republic of China.

ABSTRACT

Background: In this study, a pH and temperature dual-sensitive liposome gel based on a novel cleavable hydrazone-based pH-sensitive methoxy polyethylene glycol 2000-hydrazone-cholesteryl hemisuccinate (mPEG-Hz-CHEMS) polymer was used for vaginal administration.

Methods: The pH-sensitive, cleavable mPEG-Hz-CHEMS was designed as a modified pH-sensitive liposome that would selectively degrade under locally acidic vaginal conditions. The novel pH-sensitive liposome was engineered to form a thermogel at body temperature and to degrade in an acidic environment.

Results: A dual-sensitive liposome gel with a high encapsulation efficiency of arctigenin was formed and improved the solubility of arctigenin characterized by Fourier transform infrared spectroscopy and differential scanning calorimetry. The dual-sensitive liposome gel with a sol-gel transition at body temperature was degraded in a pH-dependent manner, and was stable for a long period of time at neutral and basic pH, but cleavable under acidic conditions (pH 5.0). Arctigenin encapsulated in a dual-sensitive liposome gel was more stable and less toxic than arctigenin loaded into pH-sensitive liposomes. In vitro drug release results indicated that dual-sensitive liposome gels showed constant release of arctigenin over 3 days, but showed sustained release of arctigenin in buffers at pH 7.4 and pH 9.0.

Conclusion: This research has shed some light on a pH and temperature dual-sensitive liposome gel using a cleavable mPEG-Hz-CHEMS polymer for vaginal delivery.

Show MeSH
Related in: MedlinePlus