Preparation of Layer‐by‐Layer Films with Remarkably Different pH‐Stability and Release Properties Using Dual Responsive Block Copolymer Micelles

Abstract

Layer‐by‐layer (LbL) films of micelles of poly[2‐(dimethylamino)ethyl methacrylate]‐b‐poly[(2‐(diethylamino)ethyl methacrylate)] (PDMA‐b‐PDEA) and poly(sodium 4‐styrenesulfonate) (PSS) with remarkably different pH‐stability and release properties are obtained via tuning film deposition conditions in a narrow pH and temperature range. Multilayers constructed at pH 8.5/25 °C or pH 8/30 °C completely disintegrate at physiologically related conditions, whereas film deposition at pH 8/25 °C produces stable films under the same conditions. Importantly, despite their stability, pH 8/25 °C multilayers release a considerable amount of pyrene at moderately acidic pH due to disintegration of the micellar cores. The amount of pyrene increases significantly at body temperature due to lower critical solution temperature (LCST)‐type phase behavior of PDMA coronal chains. The difference in properties of multilayers is explained by the extent of association among the layers which can be tuned by film deposition conditions in a narrow pH and temperature range due to dual responsive, that is, pH and temperature behavior of PDMA‐b‐PDEA micelles.

Stimuli-Responsive Polymers Providing New Opportunities for Various Applications

“…The related aggregate structures can reversibly dissolve, swell or shrink depending on the pH of the medium (Figure 4d) [27][28][29][30][31]. When these polymers are used in various surface applications such as films, layerby-layer (LbL) technology, membranes, brushes, many behaviors such as ion selective permeability, surface charge change, wettability, change in pore size and thickening/thinning of the polymer layer are encountered [32][33][34][35][36][37][38][39]. When these polymers are involved in surface applications such as membranes, numerous behaviors such as ion selective permeation and change in pore size are encountered (Figure 4f) [39][40][41][42].…”

Dually Responsive Poly(N-vinylcaprolactam)-b-poly(dimethylsiloxane)-b-poly(N-vinylcaprolactam) Polymersomes for Controlled Delivery

“…Limited tissue selectivity and the lack of targeting of anticancer therapeutics during systemic administration can result in deleterious side effects of anticancer chemotherapy [ 1 , 2 , 3 , 4 ]. To improve the efficacy of anticancer drugs, polymer-drug delivery carriers, including polymer conjugates, nanoparticles, and micelles, have been used to shield the therapeutics and prevent their premature release in healthy tissues [ 2 , 3 , 4 , 5 , 6 , 7 ].…”

“…Limited tissue selectivity and the lack of targeting of anticancer therapeutics during systemic administration can result in deleterious side effects of anticancer chemotherapy [ 1 , 2 , 3 , 4 ]. To improve the efficacy of anticancer drugs, polymer-drug delivery carriers, including polymer conjugates, nanoparticles, and micelles, have been used to shield the therapeutics and prevent their premature release in healthy tissues [ 2 , 3 , 4 , 5 , 6 , 7 ]. Among those, polymer vesicles assembled from block copolymers, i.e., polymersomes, have been recognized as effective nanocarriers because of their cell-mimetic membranes, improved colloidal and mechanical stability, and increased efficiency in drug entrapment, unlike liposomes [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ].…”