FELIPE ANTUNES SANTOS

FELIPE ANTUNES SANTOS

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CMC and PVA hydrogel containing papain nanoparticles for drug delivery
2020 - LIMA, C.S.; VARCA, G.H.; OLIVEIRA, J.R.; NOGUEIRA, K.M.; SANTOS, F.A.; RIBEIRO, A.H.; LUGAO, A.B.; FREITAS, L.F.; ROGERO, S.O.
Four hydrogel formulations of Carboxymethylcellulose (CMC) and Poly (vinyl alcohol) (PVA) were prepared with native papain (AP and BP) and papain nanoparticles (AN and BN) for drug delivery. The formulations were evaluated for their preliminary stability, protein distribution in the matrix and cytotoxicity. Three methods for sterilization purposes were compared: irradiation by 60Co source, electron-beam and UV light. The preliminary stability test confirmed that the system was stable since there was no precipitation or alteration of the organoleptic properties of the samples in the evaluated period. The distribution of proteins in the hydrogel was very homogeneous in all the formulations. Quantification of the enzymatic activity of papain after contact with the gel showed that native papain maintained its activity high (86% and 93% for AP and BP gels, respectively), whereas there was a considerable drop in the activity of the papain nanoparticles to 60.54% and 69.44% for AP and BP gels, respectively. Such loss of activity is attributed to processing and/or process steps. The cell viability assay showed that the polymer matrix shows no cytotoxicity, corroborating with the literature, since the material is biocompatible. Thus, it is possible to affirm that the developed system presents potential for biomedical application, either as a vehicle of papain itself or for the transport of other drugs through complexation with papain nanoparticles. However, the need for further studies of stability, controlled release capacity and biocompatibility is required.
Vidros biocidas baseados no sistema Nb2O5-SiO-CAO-Na2O
2016 - SILVA, A.C.; MELLO-CASTANHO, S.R.; SANTOS, F.A.; SANTOS, C.
Neste trabalho, foram desenvolvidos vidros com base no sistema de SiO-CaO-Na2O contendo diferentes teores de Nb2O5. Estes vidros foram fundidos a 1500°C por 4 horas seguido de “quenching” em molde metálico e recozimento a 500°C por duas horas e resfriamento natural no forno. Corpos de prova de aço inoxidável 316L e ligas de titânio foram recobertas com os materiais Os ensaios de caracterização utilizaram as técnicas de DRX, FT-IR e análise da expansão térmica. Também realizou-se ensaios de citotoxicidade utilizando a metodologia de absorção de vermelho neutro onde foi indicado o crescimento celular normal, o que permite a sua utilização como biomaterial. A atividade biocida foi avaliada através da incubação de vidro em suspensão bacteriana (E.coli) a 37°C sob agitação. A composição com alto teor de de SiO2 e baixo teor de Nb2O5 apresentou maior atividade biocida e o coeficiente de expansão térmica indicam compatibilidade dos materiais térmica com o aço inoxidável 316L e ligas de titânio.
Coating glass-ceramics bioactive based on Nb2O5-SiOCaO- Na2O system
2016 - MELLO-CASTANHO, SONIA; SANTOS, FELIPE; BARTOLOME, JOSE; SILVA, ANTONIO
The request for biomaterials which interact and provide proper feedback to bodily environment is increasing and so, the need for alternative materials development, from the process or biological feedback points of view, is a necessity. In this context, glass and glassceramic are interesting alternatives due to their chemical and structural characteristics possibilities. The surface coating of a specific implant with bioglass associated to biocide activity can lead to a significant impact on patient life quality, reducing risks associated to prostheses replacement due to infections, which is currently one of the most concerning and important factors in implantology. In this work, glassceramic materials based on SiO-CaO-Na2O system containing different percentages of Nb2O5 were developed. Glasses were melted at 1500°C and thermally treated at 750°C-2h. The materials were characterized by X-Ray Diffraction (XRD), to analyses indicated partial crystallization of glassy matrix. The Fourier Transform Infrared (FTIR) Spectroscopy and Dilatometry also were used to structural and thermal behavior analyses respectively. Citotoxicity tests were performed using neutral red uptake methodology and indicated normal cell growth, which enables the use as biomaterial. Biocide activity was evaluated through glass-ceramic incubation in bacterial suspension (Escherichia coli) at 37°C under shaking. A composition with higher contents of SiO2 and Nb2O5 presented higher biocide activity and coefficient of thermal expansion (CTE) evaluated indicate thermal connection with stainless steel 316L and titanium alloys.
Propriedades de vitrocerâmica do sistema SiO2-Li2O na região de transição entre metassilicato de lítio e dissilicato de lítio
2016 - SANTOS, C.; SIMBA, B.G.; SANTOS, F.A.; RIBEIRO, M.V.; ALVES, M.F.R.P.
Biocide glass based on Nb2O5-SiO-CaO-Na2O system
2016 - SANTOS, FELIPE A.; SILVA, ANTONIO C.; SANTOS, CLAUDINEI; SIMBA, BRUNO G.; BARTOLOME, JOSE F.; DURAN, TERESA; FERNANDEZ-GARCIA, ELISA; ROGERO, SIZUE O.; MELLO-CASTANHO, SONIA R.H.
In this work,glasses based on SiO-CaO-Na2O system containing different Nb2O5 contents were developed. Glasses were melted at 1500 °C and quenched in a metallic mould. Citotoxicity tests were performed using neutral red uptake methodology and indicated normal cell growth, which enables the use as biomaterial. Biocide activity was evaluated through glass incubation in bacterial suspension (Escherichia coli) at 37 °C under shaking. The composition with higher content of SiO2 and lower content of Nb2O5 presented higher biocide activity and the coefficient of thermal expansion indicate thermal compatibility with stainless steel 316L and titanium alloys.
Produção de vidrado a partir de resíduo de rochas ornamentais
2012 - TAGUCHI, S.P.; CUNHA, J.A. da; CUNHA, N.A. da; SANTOS, F.A.; SILVA, A.C.
Crystallization process of a biomaterial, the lithium disilicate, obtained from rice husk silica
2013 - SANTOS, F.A.; FERNANDES, M.H.F.V.; DAVIM, E.; PINATTI, D.G.; LAZAR, D.R.R.; SANTOS, C.
Estudo cinéticos da cristalização da biocerâmica de dissilicato de litio obtida através da silica da casca de arroz
2011 - SANTOS, F.A.; DAVIM, E.; FERNANDES, M.H.F.V.; SANTOS, C.; PINATTI, D.G.; LAZAR, D.R.R.
Estudo cinético da cristalização da biocerâmica de dissilicato de litio obtida através da silica da casca de arroz
2011 - SANTOS, F.A.; DAVIM, E.; FERNANDES, M.H.F.V.; SANTOS, C.; PINATTI, D.G.; LAZAR, D.R.R.
Lithium disilicate bioceramic obtained from alternative silica source the rice husk
2011 - SANTOS, FELIPE A.; SANTOS, CLAUDINEI dos; RODRIGUES JUNIOR, DURVAL; PINATTI, DALTRO G.; DAVIM, ERIKA; FERNANDES, MARIA H.F.V.