Highly Selective Uptake and Release of Charged Molecules by pH‐Responsive Polydopamine Microcapsules

Abstract

A systematic study of the permeation of small molecules through Pdop microcapsules is reported. The zwitterionic Pdop microcapsules are prepared by oxidative polymerization of dopamine on polystyrene microspheres followed by core removal with THF. Rhodamine 6G, methyl orange and alizarin red are chosen as differently charged probing dyes. The loading amount is affected by pH and dye concentration. Highly selective and unidirectional uptake and release of charged molecules through Pdop microcapsules can be achieved by controlling pH value: at low pH, the Pdop particles incorporate cationic dye (rhodamine 6G); at high pH, they incorporate anionic dyes (methyl orange and alizarin red). In each case, the uptake is highly selective.

Anisotropic polydopamine capsules with an ellipsoidal shape that can tolerate harsh conditions: efficient adsorbents for organic dyes and precursors for ellipsoidal hollow carbon particles

“…Interestingly, while the PS@PDA ellipsoid consists of a uorescent halo and a dark core, uorescent signals also exist in the cavity of the uorescent PDA capsules, suggesting that uorescent molecules can diffuse inside the capsules and label the interior PDA surface. 53 This is a very important property that benets the dye adsorption as will be discussed later.…”

Myoblast Cell Interaction with Polydopamine Coated Liposomes

“…as matrix polymer for molecular imprinting [18], and for life cell encapsulation [19]. PDA capsules have been considered using particles [20][21][22][23] or oil emulsion droplets [24] as templates. Although cargo loading in PDA capsules has been shown, no impact on the cell viability due to the presence of the cargo has been reported and only the absence of inherent cytotoxicity has been demonstrated.…”

Fabricating bio-inspired micro/nano-particles by polydopamine coating and surface interactions with blood platelets

“…1A). In comparison with spectrum of PS microsphere, PDA coating exhibits two adsorption peaks at 1580 cm -1 and 3220 cm -1 , which correspond to the stretching vibration of C-N/C-O and N-H/O-H, respectively [28]. Additionally, new absorption peaks at range from 1680 cm -1 to 1540 cm -1 corresponding to the stretching vibration of amide groups appear in the spectra of PS@PDA-Fib, PS@PDA-BSA, respectively [29].…”