Abstracts Book - IMRC 2018

• SB3-P005
BIODEVICE REDUCES INFLAMMATION IN THE HIPPOCAMPUS OF
A MOUSE MODEL OF ALZHEIMER’S DISEASE
Geisa Salles 1,2 , Michele Calió 2 , Cristina Pacheco Soares 3 , Marimelia Porcionatto 2 , Christian
Holscher 4 , Conceicao de Maria Vaz Elias 5 , Anderson Lobo 3,6
1
Uniiversidade do Vale do Paraiba, Institute of Research and Development, Brazil.
2 Universidade Federal de São Paulo, Laboratório de Neurobiologia, Brazil. 3 Universidade do
Vale do Paraiba, Institute of Research and Development, Brazil. 4 Lancaster University, Division
of Biomedical and Life Sciences, United Kingdom, Channel Islands & Isle of Man. 5 Universidade
Brasil, Instituto Ciência e Tecnologia, Brazil. 6 Massachusetts Institute of Technology,
Department of Chemistry, United States.
Poly (lactic acid), PLA, is a greatly used polymer for biomedical purposes. Its main
single monomer and degradation product, lactic acid, has been described as an
important energy provider to the brain under high energy demand
circumstances 1 . Here, PLA was electrospun, covered with a thin layer of gelatin
and characterized by differential scanning calorimetry (DSC) before and after 4
weeks of hydrolytic degradation. Biodevice (0.8 x 0.8 cm) was subcutaneously
implanted in APP/PS1 animals, a mouse model of Alzheimer’s disease (AD). After
4 weeks, animals were deeply anaesthetized and transcardially perfused. Brains
were coronally cryosectioned and hippocampus sections were then prepared
for immunostaining for ionized calcium binding adaptor molecule 1 (Iba-1), for
microglia, and glial fibrillary acidic protein (GFAP), for astrocytes. Samples were
incubated overnight at 4ºC with primary antibodies, then with their respective
secondary antibodies, diluted in blocking solution for 1h at room temperature.
Slides were mounted with DAPI and examined under an inverted confocal laser
scanning microscope. Data 6 animals per group were statistically analysed.
According to the DSC analysis, both glass transition (Tg) and degree of
crystallinity (Xc) of PLA are increased after 4 weeks of hydrolytic incubation,
indicating that PLA is being degraded, releasing bioproducts. Also, the thin layer
of gelatin is demonstrated to be completely degraded after 4 weeks.
Interestingly, Iba-1 and GFAP expressions in the hippocampus were diminished
(p < 0.05 and p < 0.0001, respectively) by the implanted biodevice, comparing
with APP/PS1 saline injected mice. Microglia and astrocytes activation are
involved in the immunological mechanisms in the brain, constituting a
fundamental role in the pathogenesis of AD 2 , since they are activated and
recruited to the area where amyloid protein aggregates in the brain, initiating
an inflammatory process. As both Iba-1 and GFAP expression significantly
decreased, we assume that lactic acid released the biodevice is being