Abstracts Book - IMRC 2018

• SB3-P010
POLY-(BUTYLENE ADIPATE-CO-TEREPHTHALATE) /
POLYPYRROLE/NANO-HYDROXYAPATITE SCAFFOLDS FOR BONE
TISSUE REGENERATION
Conceicao de Maria Vaz Elias 1 , Antonio Luiz Martins Maia Filho 2 , Laryssa Roque Da Silva 2 ,
Danniel Cabral Leão Ferreira 2 , Fernanda Roberta Marciano 1 , Anderson Oliveira Lobo 1
1
Universidade Brasil, Department of Biomedical Engineering, Brazil. 2 Universidade Estadual do
Piauí, Department of Mutagenesis, Brazil.
The combination of poly-(butylene adipate-co-terephthalate)(PBAT) with
polypyrrole(PPy) and nano-hydroxyapatite(nHAp) scaffolds have emerged as an
alternative for bone tissue engineering due to their excellent biodegradability,
biocompatibility, bioactivity, and electric properties. Herein, we electrospun
ultrathin PBAT/PPy/nHAp mats, which were then characterized. Their
genotoxicity was also evaluated in vivo using a micronucleus test. For scaffold
synthesis, 15g of PBAT pellets were first dissolved in 10mL of chloroform under
magnetic stirrer using a closed system. After 20h, 20mg of PPy were added into
2mL of DMF and sonicated for 5min. Next, both solutions were mixed and
electrospun (17kV, 10cm distance, 23G needle) for 40min. The electrolyte
solution used was composed of 0.042 mol L–¹ of Ca(NO3)2·4H2O + 0.025 mol L–¹
of (NH4)2HPO4. The pH was adjusted to 4.7 and the temperature to 70°C. The
nHAp thin films were electrodeposited using a classical three points electrode
(PGSTAT 128N). The mats were coupled to a working electrode (0.25 cm²) and a
platinum mesh was used as counter electrode, while Ag/AgCl (3 M KCl(aq.)) was
used as the reference electrode. The nHAp crystals were produced on PBAT/PPy
scaffolds by applying a constant potential of –3.8 V for 30 min. 4 groups were
used: PBAT/PPy (1) with and (2) without nHAp, (3) cyclophosphamide at the dose
of 50mg / kg intraperitoneally as a positive control, and (4) distilled water as a
negative control. The nanocomposites were implanted into the peritoneum
through a laparotomy. 20 male and adult albino Wistar rats were used (n=5 for
each group). After 45 and 72 hours the animals were anesthetized with ketamine
(1.0 ml/kg) and xylazine (1.1 ml/kg) intramuscularly and their blood was collected
for micronucleus analysis in Polychromatic Erythrocytes (PCEs). The frequency
of micronuclei in 2,000 PCE cells per animal was determined. The PBAT/PPy
nanofibers had a length of 0.074 ± 0.221 um. In the micronucleous test, there
was no significant difference between the membrane-exposed group with nHap
and without nHap. Neither the growth nor the frequency of micronuclei in the
chronic and acute periods were significant, and differences were not observed