Polydopamine-like Coatings as Payload Gatekeepers for Mesoporous Silica Nanoparticles

MORENO-VILLAÉCIJA, MIGUEL-ÁNGEL; SEDÓ-VEGARA, JOSEP; GUISASOLA, EDUARDO; BAEZA, ALEJANDRO; REGÍ, MARÍA VALLET; NADOR, FABIANA; RUIZ-MOLINA, DANIEL

ACS APPLIED MATERIALS & INTERFACES

AMER CHEMICAL SOC

Año: 2017

1944-8244

We report the use of bis-catecholic polymers as candidates for obtaining effective, tunable gatekeeping coatings for mesoporous silica nanoparticles (MSNs) intended for drug release applications. In monomers, catechol rings act as adhesive moieties and reactive sites for polymerization, together with middle linkers which may be chosen to tune the  physicochemical properties of the resulting coating. Stable and low-toxicitycoatings (pNDGA and pBHZ) were prepared from two biscatechols of different polarity (NDGA and BHZ) on MSN carriers previously loaded with rhodamine B (RhB) as a modelpayload, by means of a previously reported synthetic methodology and without any previous surface modification. Coating robustness and payload content were shown to depend significantly on the workup protocol. The release profiles in a model physiological PBS buffer of coated systems (RhB@MSN@pNDGA and RhB@MSN@pBHZ) showed marked differences in the ?gatekeeping? behavior of each coating, which correlatedqualitatively with the chemical nature of their respective linker moieties. While the uncoated system (RhB@MSN) lost its payload almost completely after 2 days, release from RhB@MSN@pNDGA was virtually negligible, likely due to the low polarityof the parent bis-catechol (NDGA). As opposed to these extremes, RhB@MSN@pBHZ presented the most promising behavior, showing an intermediate release of 50% of the payload in the same period of time.