Tuesday, February 21, 2017

mPEG-PLA from PolySciTech used as part of SPION-methicillin loaded nanoparticle development for eradication of drug-resistant bacterial biofilms

There is increasing prevalence of bacterial resistance towards antibiotics due to genetic as well as structural changes. Notably, certain types of bacteria tend to form into tight biofilms which are surrounded by a protective matrix that reduces antibiotic infiltration. These biofilms can be up to 1000 times more resistant towards conventional antibiotics than loose bacteria and account for up to 60% of all infectious diseases in the western world. Recently, researchers at Northeastern University utilized mPEG-PLA (PolyVivo cat# AK021) from PolySciTech division of Akina, Inc. (www.polyscitech.com) to co-encapsulate iron-oxide particles and methicillin inside polymeric nanoparticles. They discovered that these nanoparticles, under a magnetic field, were able to penetrate deep into staph-bacteria biofilms and kill the bacteria, while having no toxicity towards mammalian cells. This research holds promise for providing advanced treatment options of drug-resistant bacteria and infections at medical implant surfaces. Read more: Geilich, Benjamin M., Ilia Gelfat, Srinivas Sridhar, Anne L. van de Ven, and Thomas J. Webster. "Superparamagnetic iron oxide-encapsulating polymersome nanocarriers for biofilm eradication." Biomaterials 119 (2017): 78-85. http://www.sciencedirect.com/science/article/pii/S0142961216307086

“Abstract: The rising prevalence and severity of antibiotic-resistant biofilm infections poses an alarming threat to public health worldwide. Here, biocompatible multi-compartment nanocarriers were synthesized to contain both hydrophobic superparamagnetic iron oxide nanoparticles (SPIONs) and the hydrophilic antibiotic methicillin for the treatment of medical device-associated infections. SPION co-encapsulation was found to confer unique properties, enhancing both nanocarrier relaxivity and magneticity compared to individual SPIONs. These iron oxide-encapsulating polymersomes (IOPs) penetrated 20 μm thick Staphylococcus epidermidis biofilms with high efficiency following the application of an external magnetic field. Three-dimensional laser scanning confocal microscopy revealed differential bacteria death as a function of drug and SPION loading. Complete eradication of all bacteria throughout the biofilm thickness was achieved using an optimized IOP formulation containing 40 μg/mL SPION and 20 μg/mL of methicillin. Importantly, this formulation was selectively toxic towards methicillin-resistant biofilm cells but not towards mammalian cells. These novel iron oxide-encapsulating polymersomes demonstrate that it is possible to overcome antibiotic-resistant biofilms by controlling the positioning of nanocarriers containing two or more therapeutics. Keywords: Biofilm; Polymersome; SPION; Staphylococcus epidermidis; Antibiotic-resistance; Nanomedicine”

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