Conducting polymer- hydrogel blends for electrochemically controlled drug release devices

Abstract

Blendas formadas pela polimerização eletroquímica de pirrol em matriz de acrilamida (hidrogel) foram utilizadas, neste trabalho, como dispositivos para a liberação controlada de drogas. A influência de vários parâmetros nesta síntese, como tipo de matriz de hidrogel e condições de polimerização, foi estudada empregando-se planejamento fatorial fracionário. O objetivo final consistiu na obtenção de um material adequado para liberação baseada no controle de potencial. Para os testes de liberação foi utilizada Safranina, como substância modelo. As curvas de liberação demonstram a potencialidade do uso de tais dispositivos. Estes dispositivos foram também caracterizados por espectroscopia Raman e voltametria cíclica.Blends formed by electrochemical polymerization of polypyrrole (PPy) into polyacrylamide (PAAm) hydrogels were used as devices for controlled drug release. The influence of several parameters in the synthesis, such as type of hydrogel matrix and polymerization conditions was studied by using a fractional factorial design. The final goal was to obtain an adequate device for use in controlled release tests, based on electrochemical potential control. For controlled release tests, Safranin was used as model drug and release curves (amount of drug vs. time) have shown that these blends are promising materials for this use. The optimized blends obtained were characterized by cyclic voltammetry and Raman spectroscopy.

Conducting polymer-hydrogels for medical electrode applications

“…A number of drug release profiles have been obtained, which demonstrate that CP-hydrogel materials can be used to deliver biomolecules and drugs to tissues [25,108,111]. Small et al [111] released calcon (solochrome dark blue, MW = 416.38 Da) from a Polyacrylamide-PPy gel, and Barthus et al demonstrated release of safranin (MW = 350.84 Da) from PPy-polyacrylamide [108].…”

“…Small et al [111] released calcon (solochrome dark blue, MW = 416.38 Da) from a Polyacrylamide-PPy gel, and Barthus et al demonstrated release of safranin (MW = 350.84 Da) from PPy-polyacrylamide [108]. Both of these studies showed acute release profiles across 250 and 400 min, respectively and it is likely that longer-term profiles would be required for most chronic implants.…”

Zero-Order Release Profiles from A Multistimuli Responsive Electro-Conductive Hydrogel

“…This experiment is of relevant importance because is a clear indication of the electroactivity of the composite and the possibility of tuning the swelling behavior by the application of an electric field. In order to investigate the release kinetics and the possibility of electrochemical control, safranine was chosen as model molecule due to its size, structure and with the sake of comparison with former works performed in our group involving other composites such as polyacrylamide/PPy and Polycrylamide/PANI [22][23][24] Release profiles can be analyzed by using a molecular model on the light of the Fick's law. Hitger and Peppas [28] proposed a model that describes the solute delivery mechanism from polymeric materials that is represented by the Equation (2):…”

“…As an example, our group has demonstrated the synthesis of a polyaniline-polyacrylamide composite by electropolymerization of conducting polymer inside an insulating hydrogel matrix of different pore sizes. This resulting new material was successfully applied in electrochemical controlled release devices [22][23][24]. A number of examples of synthesis and application of ECHs can be found in a recent review on this topic [20,21].…”

Nature-inspired thermo-responsive multifunctional membrane adaptively hybridized with PNIPAm and PPy

“…Their potential has been demonstrated in a broad range of applications, such as in energy conversion and storage devices, supercapacitors, sensors, bioelectronics and medical electrodes. [20][21][22][23] The incorporation of CPs, such as polypyrrole, polyaniline and polythiophene, with a variety of polymers, metals, membranes and bioactive molecules, has been extensively studied due to their ease of synthesis, processability, and excellent environmental stability. [24][25][26] However, CPs are difficult to further modify after synthesis using post-processing methods, because they are normally non-thermoplastic, mechanically rigid and insoluble.…”