Engenharia Biomédica

URI permanente para esta coleçãohttps://repositorioacademico.universidadebrasil.edu.br/handle/123456789/33

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Comparação da liberação do fármaco Aciclovir carreado em sistemas microestruturados formados a base de Quitosana
(Universidade Brasil, 2022) Silva, Bruno Batista da; Costa, Adriana Pavinatto da
Herpes simplex virus (HSV) infections are caused by two types of viruses, type 1 (HSV 1) and type 2 (HSV-2), being endemic worldwide and a frequent public health concern. For treatment, the drug of first choice is Acyclovir, which acts by inhibiting viral DNA polymerase, however, its topical use in the form of ointments requires frequent application to achieve the desired efficacy, as it has low permeation. In this context, the use of biomaterials as a carrier in the controlled release of drugs is an interesting alternative in the health area, to improve permeation and avoid toxic effects. Among the most used biopolymers, chitosan stands out due to its high potential for applications in several areas and for being a selectively permeable material, being a good candidate for the release of topically administered drugs. In this context, in the present work, different microstructures formed based on chitosan were produced and characterized, namely: membranes, capsules and membrane + capsule for encapsulation and release of the drug Acyclovir. The membranes were produced using the casting technique (solvent evaporation) of thin film formation and the capsules were obtained through ionotropic crosslinking, using Sodium Tripolyphosphate (TPP) as a crosslinking agent. The microstructures and/or the starting materials were characterized by infrared spectroscopy (FTIR-ATR), X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), mass loss and gain through water absorption tests, mechanical stress versus deformation tests and release tests. The microstructures that showed better stability in drug encapsulation were capsules and the system composed of membrane + capsules. As for the release assay, the microstructure that presented the best result was the one composed of membrane + capsules, modulating the release in 1 hour and 20 minutes, with peak concentration at 2 hours. As for the membrane and capsule systems, both had the same conventional release profile, with the entire drug concentration being released between 15 and 20 minutes.
Produção e caracterização de membranas flexíveis a base de quitosana visando o uso como plataforma de sensores e biossensores
(Universidade Brasil, 2021) Pinto, Lidiane da Silva; Maciel, Homero Santiago; Costa, Adriana Pavinatto da
The development of new platforms for (bio) sensors is a growing area of study, as well as the use of new materials in the development of flexible platforms. Among the main characteristics of this type of platform, flexibility, biocompatibility, and non toxicity are desirable, giving the device adaptive potential, allowing it to be used even as wearable sensors. In this context, this research aimed to produce flexible membranes based on chitosan, to be used as a platform for wearable sensors. Membranes were produced using chitosan (Chi) pure or mixed with 10%, 30% and 50% (w/w) of polyethylene glycol (PEG) through the casting technique (solvent evaporation) of film formation. Additionally, a membrane with Chi / 30% PEG and gold nanoparticles (AuNps)was developed, aimingelectric conduction. Membrane characterizations were carried out through infrared absorption spectroscopy (FTIR), resistivity measurements (four points), mechanical tensile testing and thermogravimetric analysis (TGA). The results show that homogeneous and sustainable membranes, with thickness ranging from 20 to 60 µm were obtained. FTIR spectra show the main vibrational bands for Chi, PEG and AuNps chemical groups. Resistivity tests showed that all membranes are resistive to the flow of electric current, and the added concentration of AuNps did not change this property. The use of PEG as a plasticizer improved the mechanical properties of membranes. Tensile strength tests showed that membranes formed by pure chitosan are more resistant to traction and break more easily (less displacement), as those with the addition of 10% (w / w) of PEG (Chi /PEG 10%)were effectively plasticized, proving to be more flexible.TGA curves showed good thermal stability of the membranes, and between 10 and 20% of mass was lost up to a temperature of 200ºC.These results suggest that the membrane produced with Chi/PEG 10% is a promising material for use as a flexible platform.
Produção e caracterização de membranas flexíveis a base de quitosana visando o uso como plataforma de sensores e biossensores
(Universidade Brasil, 2021) Pinto, Lidiane da Silva; Costa, Adriana Pavinatto da; Maciel, Homero Santiago
The development of new platforms for (bio) sensors is a growing area of study, as well as the use of new materials in the development of flexible platforms. Among the main characteristics of this type of platform, flexibility, biocompatibility, and nontoxicity are desirable, giving the device adaptive potential, allowing it to be used even as wearable sensors. In this context, this research aimed to produce flexible membranes based on chitosan, to be used as a platform for wearable sensors. Membranes were produced using chitosan (Chi) pure or mixed with 10%, 30% and 50% (w/w) of polyethylene glycol (PEG) through the casting technique (solvent evaporation) of film formation. Additionally, a membrane with Chi / 30% PEG and gold nanoparticles (AuNps)was developed, aimingelectric conduction. Membrane characterizations were carried out through infrared absorption spectroscopy (FTIR), resistivity measurements (four points), mechanical tensile testing and thermogravimetric analysis (TGA). The results show that homogeneous and sustainable membranes, with thickness ranging from 20 to 60 µm were obtained. FTIR spectra show the main vibrational bands for Chi, PEG and AuNps chemical groups. Resistivity tests showed that all membranes are resistive to the flow of electric current, and the added concentration of AuNps did not change this property. The use of PEG as a plasticizer improved the mechanical properties of membranes. Tensile strength tests showed that membranes formed by pure chitosan are more resistant to traction and break more easily (less displacement), as those with the addition of 10% (w / w) of PEG (Chi /PEG 10%)were effectively plasticized, proving to be more flexible.TGA curves showed good thermal stability of the membranes, and between 10 and 20% of mass was lost up to a temperature of 200ºC.These results suggest that the membrane produced with Chi/PEG 10% is a promising material for use as a flexible platform.
Produção e utilização de membranas à base de quitosana e cúrcuma no processo de reparação tecidual
(Universidade Brasil, 2022) Pacheco, Karoline Maria Lopes; Costa, Adriana Pavinatto da
Tissue repair is a complex and dynamic pathophysiological process that involves distinct overlapping phases. In this context, biopolymers and natural extracts have been widely used in the development of new materials that favor the repair process. Chitosan and turmeric appear as an interesting alternative, as they have repair and antimicrobial properties, respectively. In the present work, membranes based on chitosan and turmeric were produced, characterized, and used for in vivo experiments with potential application for skin repair. The membranes were produced through the casting technique (evaporation of the solvent) of film formation, being produced membranes of chitosan 1% (m/v), chitosan mixed with glycerol 30% (m/m in relation to the mass of chitosan) and chitosan mixed with 30% glycerol + 1.5% turmeric (m/m in relation to chitosan mass). The characterizations of the physicochemical and mechanical properties of the membranes were made through measurements of absorption spectroscopy in the infrared region (FTIR), contact angle, thickness measurements and mechanical tests. Sustainable, homogeneous, and flexible membranes were obtained from all materials tested. The FTIR spectra show the main vibrational bands for chitosan and glycerol chemical groups, no band referring to turmeric was seen. Mechanical tests have shown that membranes containing glycerol are more flexible than those formed with pure chitosan. Membranes formed with glycerol and glycerol + turmeric are more hydrophilic compared to the membrane formed by pure chitosan. The results of the in vivo experiments show that the group that received the membrane of chitosan/glycerol 30%/turmeric 1.5% showed a statistically greater reduction in the injured area, as well as better results in the histological analysis, compared to the other experimental groups. The material developed here, from a natural source, low cost and easy to apply, capable of accelerating the process of repairing skin lesions, constitutes a contribution in the current literature.