Osmotically driven drug delivery through remote-controlled magnetic nanocomposite membranes.
Implantable drug delivery systems can provide long-term reliability, controllability, and biocompatibility, and have been used in many applications, including cancer pain and non-malignant pain treatment. However, many of the available systems are limited to zero-order, inconsistent, or single burst event drug release. To address these limitations, we demonstrate prototypes of a remotely operated drug delivery device that offers controllability of drug release profiles, using osmotic pumping as a pressure source and magnetically triggered membranes as switchable on-demand valves. The membranes are made of either ethyl cellulose, or the proposed stronger cellulose acetate polymer, mixed with thermosensitive poly(N-isopropylacrylamide) hydrogel and superparamagnetic iron oxide particles. The prototype devices' drug diffusion rates are on the order of 0.5-2 μg/h for higher release rate designs, and 12-40 ng/h for lower release rates, with maximum release ratios of 4.2 and 3.2, respectively. The devices exhibit increased drug delivery rates with higher osmotic pumping rates or with magnetically increased membrane porosity. Furthermore, by vapor deposition of a cyanoacrylate layer, a drastic reduction of the drug delivery rate from micrograms down to tens of nanograms per hour is achieved. By utilizing magnetic membranes as the valve-control mechanism, triggered remotely by means of induction heating, the demonstrated drug delivery devices benefit from having the power source external to the system, eliminating the need for a battery. These designs multiply the potential approaches towards increasing the on-demand controllability and customizability of drug delivery profiles in the expanding field of implantable drug delivery systems, with the future possibility of remotely controlling the pressure source.
School of Engineering, University of British Columbia , Kelowna, British Columbia V1V 1V7, Canada.
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Zaher
Smart Hybrid Materials (SHMs) Lab, Advanced Membranes and Porous Materials Center, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955, Saudi Arabia.
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Li
Department of Mechanical Engineering, University of California at Berkeley , California 94720, USA.
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Wolf
Department of Mechanical Engineering, University of California at Berkeley , California 94720, USA.
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Pirmoradi
Computer, Electrical and Mathematical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955, Saudi Arabia.
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Yassine
Department of Mechanical Engineering, University of California at Berkeley , California 94720, USA.
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Lin
Smart Hybrid Materials (SHMs) Lab, Advanced Membranes and Porous Materials Center, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955, Saudi Arabia.
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Khashab
Computer, Electrical and Mathematical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955, Saudi Arabia.
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Kosel