Drug carriers that have high targeting efficiency are often required in drug development. It is crucial to understand how the drug carrier properties can be tailored to avoid immune recognition and improve targeting cell association. Polymer based capsules are of particular interest in drug delivery as their physicochemical properties can be tailored. Interaction of spherical polymeric capsules with cells has been studied extensively, however the effects of carrier shape and their potential to enhance systemic targeting have yet to be fully elucidated.<br/>Herein, we report a templating method for the engineering of functional polymer capsules with different aspect ratios through a novel fabrication method, termed continuous assembly of polymers (CAP). Poly(ethylene glycol) (PEG) is known for its immunologically stealth properties and PEG capsules with different aspect ratios of 1, 8, 15, and 20 were fabricated. A bi-specific antibody which binds to both PEG and epidermal growth factor receptor (EGFR) was added to the PEG capsules. The targeting efficiency of these capsules with tuned antibody concentration and shape was studied <i>in vitro</i>. EGFR positive human breast cancer cell line MDA-MB-468, EGFR negative hamster ovary cell line CHO-K1 and murine macrophage cell line RAW264.7 were tested against capsule association. It was found that capsules with elongated shapes significantly improved positive cellular association while maintaining negligible negative association. With the same surface area, capsules with aspect ratio 20 had 2 folds increase in cancer cell association compared to the spherical counterparts after 1 hour incubation. All of the PEG capsules regardless of shape could achieve up to 98% of targeting if incubating for 5 hours. PEG capsules were further conjugated with anti-cancer drug doxorubicin to allow pH triggered intracellular release of drug. This study will enable a rational selection of capsule design for future development.

Harnessing shape and bi-specific antibodies for improved cell-targeting efficiency of poly(ethylene glycol) capsules

253rd National Meeting (2017)

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