Tuesday, April 8, 2014

In-vivo drug delivery to cancer by targeted PLGA-PEG

PolySciTech (www.polyscitech.com) provides a variety of both block copolymers (PEG-PLGA) as well as functional block copolymers (PLGA-PEG-COOH, -NHS, -Mal).  Recently these types of polymers have been used to create a micelle delivery system by conjugating A10 PSMA Aptin to the PEG terminus of the micelle. Read more: Cheng, Jianjun, Benjamin A. Teply, Ines Sherifi, Josephine Sung, Gaurav Luther, Frank X. Gu, Etgar Levy-Nissenbaum, Aleksandar F. Radovic-Moreno, Robert Langer, and Omid C. Farokhzad. "Formulation of functionalized PLGA–PEG nanoparticles for in vivo targeted drug delivery." Biomaterials 28, no. 5 (2007): 869-876. http://dx.doi.org/10.1016/j.biomaterials.2006.09.047


“Abstract:  Nanoparticle (NP) size has been shown to significantly affect the biodistribution of targeted and non-targeted NPs in an organ specific manner. Herein we have developed NPs from carboxy-terminated poly(d,l-lactide–co  –glycolide)–block–  poly(ethylene glycol) (PLGA–b  –PEG–COOH) polymer and studied the effects of altering the following formulation parameters on the size of NPs: (1) polymer concentration, (2) drug loading, (3) water miscibility of solvent, and (4) the ratio of water to solvent. We found that NP mean volumetric size correlates linearly with polymer concentration for NPs between 70 and 250 nm in diameter (linear coefficient=0.99 for NPs formulated with solvents studied). NPs with desirable size, drug loading, and polydispersity were conjugated to the A10 RNA aptamer (Apt) that binds to the prostate specific membrane antigen (PSMA), and NP and NP-Apt biodistribution was evaluated in a LNCaP (PSMA+) xenograft mouse model of prostate cancer. The surface functionalization of NPs with the A10 PSMA Apt significantly enhanced delivery of NPs to tumors vs. equivalent NPs lacking the A10 PSMA Apt (a 3.77-fold increase at 24 h; NP-Apt 0.83%±0.21% vs. NP 0.22%±0.07% of injected dose per gram of tissue; mean±SD, n=4, p=0.002). The ability to control NP size together with targeted delivery may result in favorable biodistribution and development of clinically relevant targeted therapies. Keywords: Drug delivery; Nanoparticle; PLGA; Prostate cancer; Targeting; Aptamer”

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