title: Ultrasound enhanced matrix metalloproteinase-9 triggered release of contents from echogenic liposomes.
abstract: The extracellular enzyme matrix metalloproteinase-9 (MMP-9) is overexpressed in atherosclerotic plaques and in metastatic cancers. The enzyme is responsible for rupture of the plaques and for the invasion and metastasis of a large number of cancers. The ability of ultrasonic excitation to induce thermal and mechanical effects has been used to release drugs from different carriers. However, the majority of these studies were performed with low frequency ultrasound (LFUS) at kilohertz frequencies. Clinical usage of LFUS excitations will be limited due to harmful biological effects. Herein, we report our results on the release of encapsulated contents from substrate lipopeptide incorporated echogenic liposomes triggered by recombinant human MMP-9. The contents release was further enhanced by the application of diagnostic frequency (3 MHz) ultrasound. The echogenic liposomes were successfully imaged employing a medical ultrasound transducer (4-15 MHz). The conditioned cell culture media from cancer cells (secreting MMP-9) released the encapsulated dye from the liposomes (30-50%), and this release is also increased (50-80%) by applying diagnostic frequency ultrasound (3 MHz) for 3 min. With further developments, these liposomes have the potential to serve as multimodal carriers for triggered release and simultaneous ultrasound imaging.
authors: Department of Pharmaceutical Sciences, North Dakota State University, Fargo, North Dakota 58108, United States.
authors: Rahul
authors: R
authors: Nahire
authors: Shirshendu
authors: S
authors: Paul
authors: Michael D
authors: MD
authors: Scott
authors: Raushan K
authors: RK
authors: Singh
authors: Wallace W
authors: WW
authors: Muhonen
authors: John
authors: J
authors: Shabb
authors: Kara N
authors: KN
authors: Gange
authors: D K
authors: DK
authors: Srivastava
authors: Kausik
authors: K
authors: Sarkar
authors: Sanku
authors: S
authors: Mallik
mesh_terms: D045744:Cell Line, Tumor; D006367:HeLa Cells; D006801:Humans; D008081:Liposomes / Q000737:chemistry* / Q000378:metabolism; D061986:MCF-7 Cells; D020780:Matrix Metalloproteinase 9 / Q000737:chemistry* / Q000378:metabolism; D014465:Ultrasonics / Q000379:methods*
chemical_list: D008081:Liposomes; D020780:Matrix Metalloproteinase 9