STUDY OF pH-RESPONSIVE BIOPOLYMER-SILICA COMPOSITES WITH POTENTIAL BIOACTIVITY FOR PERIODONTAL TISSUE REGENERATION WITH ANTIOXIDANT ACTIVITY

CE OLIVETTI; M R ALONSO; MF DESIMONE; ME ALVAREZ ECHAZU; O PERNA; GS ALVAREZ; I PERALTA; C ANESINI

Buenos Aires

Congreso; Reunion conjunta de sociedades de Biociencia; 2017

Sociedad Argentina de farmacología Experimental

STUDY OF pH-RESPONSIVE BIOPOLYMER-SILICA COMPOSITES WITH POTENTIAL BIOACTIVITY FOR PERIODONTAL TISSUE REGENERATION WITH ANTIOXIDANT ACTIVITYTemperature and pH are some of the variables in which materials can respond differently and therefore they are able to modulate their behavior. Particularly, chitosan (Chi) polymer amino groups, carboxylic acid groups from carboxymethylcellulose (CMC) and silanol groups from silica nanoparticles may play a role in the development of pH-responsive composites. We present pH-responsive composites with a differential mucoadhesive profile throughout periodontal disease. Saliva from patients with gingivitis presents a higher pH than saliva from patients with periodontitis. Accordingly, the swelling profile of Chi-SiO2-CMC and Chi-SiO2 composites shows a greater affinity for water at a pH of 7.5 in contrast to a pH of 6.5, encouraging their mucoadhesion. Besides, we performed an EDS-SEM analysis from Chi-SiO2-CMC and Chi-SiO2 composites after soaking in simulated body fluid for 14 days. Results revealed that only Chi-SiO2 composites showed an accumulation of Ca++. Silanol groups could provide an environment for possible biomineralization. The supersaturation of Ca++ near a negative surface could trigger the nucleation of hydroxyapatite. The addition of CMC discouraged Ca++ accumulation. The development of bioactive composites could promote the regeneration of periodontal tissue in periodontitis. Although the mucoadhesion of both composites at pH 6.5 is lower, Chi-SiO2 could possibly be used for regeneration of osseous tissues.We also incorporated Larrea divaricata aqueous extract to the Chi-SiO2-CMC composites and evaluated its release profile at a pH of periodontitis saliva. L. divaricata is a plant with antioxidant and anti-inflammatory activities, thus it can be used in the treatment of periodontal disease. L. divaricata release was measured by HPLC. In parallel, DPPH scavenger activity was assayed in order to evaluate antioxidant activity. The extract was released from the composites for over 48 hs and conserved its antioxidant activity.keywords: chitosan, composite, antioxidant activity