IFISUR   23398
INSTITUTO DE FISICA DEL SUR
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Synthesis and characterization of bentonite/alginate based nanocomposite for drug delivery
Autor/es:
M.M.S. LENCINA; M.D. NINAGO; R.O. DI SANTO; A.E. CIOLINO; M.A. VILLAR
Lugar:
Ciudad Autónoma de Buenos Aires
Reunión:
Conferencia; COMAT 2015 : 6th International Conference on Science and Technology of Composite Materials; 2015
Institución organizadora:
Facultad de Ingeniería, UBA
Resumen:
In drug therapy, it is important to provide therapeutic levels of drug during treatment time. Therefore, it is desirable to minimize temporal variations in drug concentration to avoid periods of over-dosing or under-dosing. New strategies are focused on modifying drug delivery systems (DDS) by means of addition of clay minerals into polymer matrix. Although clay minerals and polymers are frequently used as single drug carriers, in some cases this type of DDS does not meet all desired requirements. Thus, the preparation of polymer layered silicate composites offers the possibility to improve some properties, such as swelling capacity, film forming abilities, and rheological behaviour, among others. Alginate (ALG) is a polysaccharide, biocompatible, biodegradable and widely used in gel formation due to its unique property of forming insoluble calcium alginate (Ca-ALG) gels through ionotropic gelation with Ca2+(ac) ions. Poly(N-isopropylacrylamide) (PNIPAAm) is a thermoresponsive polymer with a lower critical solution temperature (LCST) in aqueous media, close to 30?35°C. PNIPAAm is hydrophilic below LCST, and hydrophobic above it. The use of both polymers in hydrogel formation conduces to thermo-sensitive DDS. Atenolol delivery from hydrogels based on ALG and ALG-g-PNIPAAm were previously studied at 37°C (body temperature). Ca-ALG presented instantaneous release of the drug, reaching the maximum percentage of release after 5 minutes of starting the swelling assay. Addition of PNIPAAm into the matrix improved the drug release profile; obtaining the maximum release after 1 hour. With the intention of obtaining biocompatible DDS with a controlled and sustained release, composites were obtained employing modified bentonite (BN) as filler in hydrogels of ALG and ALG/PNIPAAm crosslinked by Ca2+(ac) ions. BN was modified by pillared process producing the expansion of the interlayer clay space. This feature might improve the compatibility with the polymer. Composites synthesized were structurally characterized and they were used for swelling assays. Drug delivery measurements are being studied.