Showing posts with label ultrasound-triggered. Show all posts
Showing posts with label ultrasound-triggered. Show all posts

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Design and evaluation of doxorubicin-containing microbubbles for ultrasound-triggered doxorubicin delivery: cytotoxicity and mechanisms involved.

Mol Ther. 2010 Jan;18(1):101-8

Authors: Lentacker I, Geers B, Demeester J, De Smedt SC, Sanders NN

Drug delivery with microbubbles and ultrasound is gaining more and more attention in the drug delivery field due to its noninvasiveness, local applicability, and proven safety in ultrasonic imaging techniques. In this article, we tried to improve the cytotoxicity of doxorubicin (DOX)-containing liposomes by preparing DOX-liposome-containing microbubbles for drug delivery with therapeutic ultrasound. In this way, the DOX release and uptake can be restricted to ultrasound-treated areas. Compared to DOX-liposomes, DOX-loaded microbubbles killed at least two times more melanoma cells after exposure to ultrasound. After treatment of the melanoma cells with DOX-liposome-loaded microbubbles and ultrasound, DOX was mainly present in the nuclei of the cancer cells, whereas it was mainly detected in the cytoplasm of cells treated with DOX-liposomes. Exposure of cells to DOX-liposome-loaded microbubbles and ultrasound caused an almost instantaneous cellular entry of the DOX. At least two mechanisms were identified that explain the fast uptake of DOX and the superior cell killing of DOX-liposome-loaded microbubbles and ultrasound. First, exposure of DOX-liposome-loaded microbubbles to ultrasound results in the release of free DOX that is more cytotoxic than DOX-liposomes. Second, the cellular entry of the released DOX is facilitated due to sonoporation of the cell membranes. The in vitro results shown in this article indicate that DOX-liposome-loaded microbubbles could be a very interesting tool to obtain an efficient ultrasound-controlled DOX delivery in vivo.

PMID: 19623162 [PubMed - indexed for MEDLINE]

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Comparing encapsulation efficiency and ultrasound-triggered release for protein between phospholipid-based microbubbles and liposomes.

J Microencapsul. 2009 Jun 19;

Authors: Lu CT, Zhao YZ, Gao HS, Tian JL, Zhou ZC, Zhao GT, Tang QQ, Jin Z, Xu YY, Huang PT, Han J, Wang L, Li XK

This work was to compare the encapsulation efficiency and ultrasound-triggered release for protein between microbubbles and liposomes. Bovine serum albumin (BSA) was used as a model. Final ratios between BSA and HPC in microbubbles and liposomes were 1 : 5, 1 : 7 and 1 : 10, respectively. Morphologic characteristics and contrast enhancement of loaded microbubbles and liposomes were measured. Encapsulation efficiency and ultrasound-stimulated release profile were detected. The mean size of loaded microbubbles and liposomes was 3.4 microm and 1.7 microm, respectively. Encapsulation efficiency of microbubbles had an inverse relationship with the ratio between BSA and HPC, while loaded liposomes remained nearly unchanged in the designed range of the ratio between BSA and HPC. Microbubbles resulted in significant enhancement of CnTi images. After ultrasound, more than 90% of the entrapped BSA was released from microbubbles, but less than 5% of BSA released from liposomes. Microbubbles are a promising delivery system for proteins.

PMID: 19538032 [PubMed - as supplied by publisher]

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