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298 results on '"Fajardo, André R."'

15. First report of electrospun cellulose acetate nanofibers mats with chitin and chitosan nanowhiskers: Fabrication, characterization, and antibacterial activity

Author

Pereira, Antonio GB, Fajardo, André R, Gerola, Adriana P, Rodrigues, Jean HS, Nakamura, Celso V, Muniz, Edvani C, and Hsieh, You-Lo

Subjects
Engineering, Biomedical Engineering, Nanotechnology, Bioengineering, Animals, Anti-Bacterial Agents, Biocompatible Materials, Cellulose, Chitin, Chitosan, Chlorocebus aethiops, Escherichia coli, Nanofibers, Vero Cells, 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide, Cellulose acetate, Chitin nanowhiskers, Chitosan nanowhiskers, Electrospun nanofibers mats, Hydrochloric acid, Physical adsorption, Sodium hydroxide, Macromolecular and Materials Chemistry, Organic Chemistry, Food Sciences, Polymers, Food sciences, Biochemistry and cell biology, Chemical engineering
Abstract

Physical adsorption has shown to be facile and highly effective to deposit chitosan nanowhiskers (CsNWs, 60 % deacetylated, length: 247 nm, thickness: 4-12 nm, width:15 nm) on electrospun cellulose acetate nanofibers (CANFs, 560 nm) to effect complete surface charge reversal from negatively charged CANFs (-40 mV) to positively charged CsNWs-adsorbed CANFs (+8 mV). The CsNWs coverage did not alter the smooth and homogeneous morphology of fibers, as observed from SEM images. Biological assays showed the CsNWs covered nanofibers were effective against the Gram-negative bacterium E. coli, reducing 99 % of colony forming units (CFU) in 24 h and atoxic to healthy Vero cells. The use of CsNWs to modify cellulose fiber surfaces has been proved to be efficient and may be applied to a broad scope of fields, especially as biomaterials and biomedical applications.

Published
2020

29. Enhancement of Cashew (Anacardium occidentaleL.) Seedlings Growth in Semiarid Regions Using a Superabsorbent Hydrogel Composite

Author

de Albuquerque, Haroldo P., Irineu, Toni H. S., Costa, James N., Lima, Joilson S., Pinheiro Neto, Luis G., Fajardo, André R., and Rodrigues, Francisco H. A.

Abstract

In arid and semiarid regions, agricultural producers, including cashew growers, grapple with the challenges of cultivating crops in harsh environmental conditions. To address this issue, conditioning materials capable of maintaining soil moisture levels even during droughts presents a promising solution. Herein, we synthesized a superabsorbent hydrogel composite comprised of starch-grafted-poly(sodium acrylate) embedded with 20% (w/w) kaolin (KAO), designed to enhance the quality of cashew seedlings. Characterization of the composite through Fourier transform infrared (FTIR) and X-ray diffraction (XRD) analyses confirmed its successful synthesis. The incorporation of KAO influenced the thermal, morphological, and swelling properties of the composite, as a result of the interaction between the clay and starch. Moreover, the composite exhibited improved water absorption capacity and kinetics, demonstrating a superabsorbent behavior. Our findings demonstrated that the addition of just 1% (w/w) of the composite effectively enhanced soil moisture retention. Notably, the placement of the composite within the soil column proved critical in extending the interval between irrigation cycles. Field experiments revealed that cashew seedlings cultivated in soil conditioned with the composite positioned deeper in the pot exhibited notable improvements in morphological parameters such as plant height, stem diameter, and leaf count, especially over prolonged cultivation periods. Besides, these seedlings displayed increased vigor and overall quality, essential for the establishment of robust and healthy cashew orchards. Overall, this study underscores the potential of this composite as a promising and cost-effective soil conditioning material for enhancing cashews and other crop yields in arid and semiarid regions with limited water availability.

Published
2024
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30. Controlled Release of Curcumin from Hydrogels: Biomedical Applications with a Focus on Neurodegenerative Diseases

Author

Universidad de Sevilla. Departamento de Química Analítica, de Andrade, Ângela G. L. L., Sangaletti, Patrícia, Ricken, Yara S., da Costa, Juliê S., de Lima, Idglan S., Parize, Alexandre L., Marin, Camila F. F., Gerola, Adriana P., Fajardo, André R., da Silva Filho, Edson C., Orta Cuevas, María del Mar, Muniz, Edvani C., Universidad de Sevilla. Departamento de Química Analítica, de Andrade, Ângela G. L. L., Sangaletti, Patrícia, Ricken, Yara S., da Costa, Juliê S., de Lima, Idglan S., Parize, Alexandre L., Marin, Camila F. F., Gerola, Adriana P., Fajardo, André R., da Silva Filho, Edson C., Orta Cuevas, María del Mar, and Muniz, Edvani C.

Abstract

A lot of works have shown Curcumin (Cur) as a potential candidate in the treatment of neurodegenerative diseases (NDDs) such as atherosclerosis, stroke, Huntington’s, Alzheimer’s, and Parkinson’s. The therapeutic potential of Cur in NDDs has been linked to its antioxidant, anti-inflammatory, and anti-protein aggregation effects. However, one of the main factors that have limited the application of Cur is the scarcity of clinical trials to evaluate its therapeutic efficacy due to its extremely low aqueous solubility, instability, low oral bioavailability associated with the low aqueous solubility, rapid metabolism, and elimination from the bloodstream. Hydrogel matrixes are an interesting way for Cur carrying, mainly to protect the Cur against instability and enhance the low bioavailability. The encapsulation of Cur in polymeric micelles and hydrogels is an example of an important strategy to facilitate its delivery and release in the human body to protect against several diseases, including in NDDs. Therefore, 3D matrices of hydrogels, made up of polymers, are materials with characteristics and requirements suitable for applications such as drug delivery systems (DDS). This chapter centers around the neuroprotective properties of Cur and its utilization in both the treatment and prevention of NDDs. Almost 180 references are cited ca. 120 of them published in the last 5 years.

Published
2024

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