Evaluation of a new liposome preparation technique, the freeze-thawing method, using L-asparaginase as a model drug.

Ohsawa, Takashi; Miura, Hiroshi; Harada, Kiyoshi

doi:10.1248/cpb.33.2916

Cited by 20 publications

(5 citation statements)

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“…The concentration of TMX in this solution was determined by measuring the UV absorbance at a wavelength of 254 nm using UV spectrophotometer. The following equations have been used to calculate the percentage of encapsulation efficiency (EE) and loading capacity (LC) of TMX on nanocapsules (Ohsawa et al 1985;Piacentini 2016 temperatures. In order to determine the released TMX concentration, 5 ml of the drug release medium was taken (immediately replaced with 5 mL fresh PBS to maintain sink conditions) at predetermined time intervals and diluted to 10 ml using PBS solution and cumulative drug release profiles were recorded.…”

Section: Tamoxifen Encapsulation Efficiency and Loading Capacity Determinationmentioning

confidence: 99%

Tamoxifen-loaded PLA/DPPE-PEG lipid-polymeric nanocapsules for inhibiting the growth of estrogen-positive human breast cancer cells through cell cycle arrest

2020

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The strategy of drug encapsulation with biocompatible polymeric nanocapsules could be a promising approach to improve the delivery of poorly water-soluble drugs for cancer therapy. The aim of this study was to investigate the drug delivery of tamoxifen from biocompatible nanocapsules made of poly (D,L-lactide) (PLA) c o r e a n d 1 , 2 -d i p a l m i t o y l -s n -g l y c e r o -3phosphoethanolamine-N-[methoxy(polyethyleneglycol)-2000] (DPPE-PEG) shell in the treatment of breast cancer.The analytical techniques such as FTIR, XRD, SEM, and TEM were used to investigate the structure of nanocapsules. Tamoxifen drug encapsulation efficiency and loading percentages as well as release kinetics at different pH values and temperatures were used to confirm the appropriate performance of these novel nanocapsules. The maximum tamoxifen release occurred at 40°C, pH = 4. Based on the SEM and TEM images, the sizes of nanocapsules were between 57 and 159 nm. In order to investigate the anticancer effects and cytotoxicity of encapsulated tamoxifen in PLA/DPPE-PEG nanocapsules, the tetrazolium-based colorimetric (MTT) assay and cell cycle arrest analysis on MCF-7 breast cancer cell were performed. Also, cell cycle-related gene expressions of p53 and p21 in treated MCF-7 cells with tamoxifen-loaded PLA/DPPE-PEG nanocapsules were evaluated. The results of MTT cell proliferation experiments exhibited an increase in the cytotoxicity of tamoxifen nanocapsules on MCF-7 cell line compared with free tamoxifen. The 1.2-fold increase in the G1 stage compared with the control group in the cell cycle arrest protocol as well as the notable overexpression of p53 and p21 genes suggested that these nanocapsules arrested cell cycle in MCF-7 cells.

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Section: Tamoxifen Encapsulation Efficiency and Loading Capacity Determinationmentioning

confidence: 99%

Tamoxifen-loaded PLA/DPPE-PEG lipid-polymeric nanocapsules for inhibiting the growth of estrogen-positive human breast cancer cells through cell cycle arrest

2020

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“…Freezing and thawing method is convenient for increasing the trapped volume of MLV preparations [2][3][4]. The mechanism by which the freeze-thawing process increases the trapped volume is not clear.…”

Section: Introductionmentioning

confidence: 99%

“…However, it likely reflects a physical disruption of lamellar structure, probably due to ice crystals formed during the freezing process [1,5]. While the influences of the freeze-thawing process on the physical properties of the lipid bilayer have been described in many reports [1][2][3][4][5][6][7][8], few studies have attempted to investigate the effect of freeze-thawing on the formation of liposomes containing polyethylene glycol (PEG)-lipid [9][10][11]. The presence of hydrophilic PEG molecules on the surface of the bilayer could affect vesicle structure change during the freezethawing process.…”

Section: Introductionmentioning

confidence: 99%

Effect of Freeze-Thawing Process on the Size and Lamellarity of PEG-Lipid Liposomes

Sriwongsitanont¹,

Ueno

2011

TOCOLLSJ

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The influence of the freeze-thawing process on the size and lamellarity of multilamellar PEG-lipid liposomes prepared from a mixture of egg yolk phosphatidilcholine (EggPC) and distearoyl phosphatidylethanolamine polyethyleneglycol (DSPE-PEG) 2000 was investigated. Trapped volume measurement, quasielastic light scattering (QELS) and freeze-fracture electron microscopy were used to estimate the morphology and lamellarity of liposomes. During the freeze-thawing process, the lamellarity of multilamellar vesicles (MLVs) depended strongly on both PEG-lipid concentration and the number of freeze-thaw cycles. The decrease in the number of lamellae was a function of the number of freeze-thaw cycles. The increase in trapped volume coincided with the decrease in the number of lamellae observed in electron micrographs. After comparing the results obtained from EggPC/DSPE-PEG2000 MLV and from pure EggPC MLV, it was concluded that during the freeze-thawing the liposomes with DSPE-PEG2000 achieved a unilamellar structure more readily than the pure EggPC liposomes.

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“…Hydration was allowed to occur for 30 min at 45 °C with 30 s of vortexing every 5 min. Liposomes were then subjected to 5 freeze–thaw cycles: 3 min in liquid nitrogen followed by 5 min in a 45 °C water bath . Solutions were vortexed for 30 s after each thaw cycle.…”

Section: Methodsmentioning

confidence: 99%

Orthogonal Self-Assembly of Amphiphilic Peptide Hydrogels and Liposomes Results in Composite Materials with Tunable Release Profiles

Swain,

Yang,

Hartgerink

2023

Biomacromolecules

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Self-assembled nanomaterials are promising candidates for drug delivery by providing a higher degree of spatiotemporal control compared to free drugs. However, challenges such as burst release, inadequate targeting, and drugnanomaterial incompatibility leave room for improvement. The combination of orthogonal self-assembling systems can result in more useful materials that improve upon these weaknesses. In this work, we investigate an orthogonal self-assembling system of nanofibrous MultiDomain Peptide (MDP) hydrogels encapsulating liposomes. Both positively charged and negatively charged MDPs were prepared and mixed with positively charged, negatively charged, or zwitterionic liposomes for a total of six composites. We demonstrate that, despite both systems being amphiphilic, they are able to mix while retaining their independent identities. We show that changing the charge of either liposomes or MDPs does not hinder the self-assembly of either system or significantly affect their rheological properties. In all six cases, small molecules encapsulated in liposome-MDP composites resulted in slower release than was possible in MDP hydrogels alone. However, in one case, positively charged MDPs destabilized negatively charged liposomes and resulted in a unique release profile. Finally, we show that MDP hydrogels substantially decrease the release of chemotherapeutic doxorubicin from its liposomal formulation, Doxil, for 24 h. This work demonstrates the chemical compatibility of amphiphilic, orthogonally self-assembled systems and the range of their drug-delivering capabilities.

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Evaluation of a new liposome preparation technique, the freeze-thawing method, using L-asparaginase as a model drug.

Cited by 20 publications

References 0 publications

Tamoxifen-loaded PLA/DPPE-PEG lipid-polymeric nanocapsules for inhibiting the growth of estrogen-positive human breast cancer cells through cell cycle arrest

Tamoxifen-loaded PLA/DPPE-PEG lipid-polymeric nanocapsules for inhibiting the growth of estrogen-positive human breast cancer cells through cell cycle arrest

Effect of Freeze-Thawing Process on the Size and Lamellarity of PEG-Lipid Liposomes

Orthogonal Self-Assembly of Amphiphilic Peptide Hydrogels and Liposomes Results in Composite Materials with Tunable Release Profiles

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