Study of different variables affecting payload control release in pH sensitive Coordination Polymer Particles (CPPs)

F, NADOR; F. NOVIO; D. RUIZ-MOLINA

Barcelona

Workshop; THIRD WORKSHOP ON NANOMEDICINE UAB-CEI; 2014

Coordination Polymers Particles (CPPs), defined as backbones built by metal ions andpolydentated bridging ligands, represent a promising new family of materials [1] withremarkable advantages such as low cost, facile production and compositional and structuraldiversity [2]. By the scaling them down to nanometer area, the scope of CPPs have beenenormously expanding, specifically in the medical applications field as drug deliverysystems, enhancing the permeability and retention of drugs in solid tumours and decreasingthe systemic toxicity [3].Our group has been dedicated during the last years to the synthesis and application ofthe amorphous Coordination Polymer Nanoparticles for the encapsulation and release ofdifferent drugs or active ingredients [4]. Nevertheless most of these reports have tended tofocus on release percentage of the encapsulated substrate rather than the mechanism itselfand the different variables that can play a crucial role. In view of this, the main aim of thisstudy was to understand possible interactions between encapsulated species and CPPs, theeffect of the buffer used to control the pH and the nature of the encapsulated species.In order to achieve that goal different factors were evaluated. Analogous pH and nonpH responsive CPPs that encapsulate dyes with different nature (pKa, solubility, etc) weretested. Moreover, in the course of release process, we also focused into the buffers pH ortheir ionic strength. Preliminary results have shown a logic tendency in the percentage ofrelease based mainly on electrostatic interactions between dyes and CPPs employed. Insummary, the current findings would open substantially a new perspective for the CPPsapplications, due to the prediction of the best combinations of guest (dye, drug, etc) and host(CPPs).