Navegando por Assunto "Biomedical Materials"

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    In vitro and in vivo evaluation of rotary-jet-spun poly(ɛ- caprolactone) with high loading of nano-hydroxyapatite
    (Springer) Andrade, Telmo M.; Mello, Daphne de Camargo Reis; Elias, Conceição de Maria Vaz; Abdala, Julia Marinzeck de Alcantara; Silva, Edmundo; Vasconcellos, Luana Marotta Reis de; Tim, Carla Roberta; Marciano, Fernanda Roberta; Lobo, Anderson Oliveira
    Herein, poly(ɛ-caprolactone) (PCL) mats with different amounts of nanohydroxyapatite (nHAp) were produced using rotary- jet spinning (RJS) and evaluated in vitro and in vivo. The mean fiber diameters of the PCL, PCL/nHAp (3%), PCL/nHAp (5%), and PCL/nHAp (20%) scaffolds were 1847±1039, 1817±1044, 1294±4274, and 845±248nm, respectively. Initially, all the scaffolds showed superhydrophobic behavior (contact angle around of 140oC), but decreased to 80° after 30 min. All the produced scaffolds were bioactive after soaking in simulated body fluid, especially PCL/nHAp (20%). The crystallinity of the PCL scaffolds decreased progressively from 46 to 21% after incorporation of 20% nHAp. In vitro and in vivo cytotoxicity were investigated, as well as the mats’ ability to reduce bacteria biofilm formation. In vitro cellular differentiation was evaluated by measuring alkaline phosphatase activity and mineralized nodule formation. Overall, we identified the total ideal amount of nHAp to incorporate in PCL mats, which did not show in vitro or in vivo cytotoxicity and promoted lamellar bone formation independently of the amounts of nHAp. The scaffolds with nHAp showed reduced bacterial proliferation. Alizarin red staining was higher in materials associated with nHAp than in those without nHAp. Overall, this study demonstrates that PCL with nHAp prepared by RJS merits further evaluation for orthopedic applications
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    Retraction Note to: In vitro and in vivo evaluation of rotary-jet-spun poly(ɛ-caprolactone) with high loading of nano-hydroxyapatite
    (Springer) Andrade, Telmo M.; Mello, Daphne de Camargo Reis; Elias, Conceição de Maria Vaz; Abdala, Julia Marinzeck de Alcantara; Silva, Edmundo; Vasconcellos, Luana Marotta Reis de; Tim, Carla Roberta; Marciano, Fernanda Roberta; Lobo, Anderson Oliveira
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    Synthesis and Characterization of Chloroaluminium Phthalocyanine Incorporated in PLA/Gelatin Bionanocomposites for Photodynamic Therapy
    Carvalho, Janicy Arantes; Ambrosio, Jéssica Aparecida Ribeiro; Marcolino, Luciana Maria Cortez; Simioni, Andreza Ribeiro; Ribeirão Preto
    Development delivery systems, such as nanoparticles, represent a growing area in biomedical research. Nanoparticles were prepared using a combination of two methods, the desolvation / emulsion technique using poly (lactic acid) (PLA) and gelatin (nPLA-G) forming a bionanocomposites which are hybrid materials composed of a biodegradable material and a nanodimensional material. Chloroaluminum phthalocyanine (ClAlPc) was chose as photosensitizer (PS). ClAlPc is a second generation of photosensitizer used in photodynamic therapy (PDT). ClAlPc loaded nanoparticles (nPLA-G/ClAlPc) were prepared using the same process. The PLA-gelatin nanoparticles were successfully prepared by the combination of desolvation / emulsion technique. The nanoparticles presented uniform size and spherical shape. The mean nanoparticle size was 655.1 ± 202.8 nm for nPLA-G (PDI = 0.163) and 772.2 ± 239.4 nm for nPLA-G/ClAlPc (PDI = 0.134). The zeta potential for nPLA-G and nPLA-G/ClAlPc revealed an average value of + 10.0 ± 3.15 mV and + 15.9 ± 3.29 mV, respectively. ClAlPc loaded nanoparticles maintain its photophysical behavior after encapsulation. The encapsulation efficiency was of 90.89 ± 7.55%. All the physical–chemical and photophysical measurements performed allow us to reinforce the idea of a new nanoparticle, composed of PLA and gelatin, as drug delivery systems for PDT.