ABSTRACT
Significant problems have arisen in recent years, such as global warming and hunger. These complications are related to the depletion and exploitation of natural resources, as well as environmental pollution. In this context, bioprocesses and biorefinery can be used to manage agro-industrial wastes for obtaining high-value-added products. A large number of by-products are composed of lignin and cellulose, having the potential to be exploited sustainably for chemical and biological conversion. The biorefinery of agro-industrial wastes has applications in many fields, such as pharmaceuticals, medicine, material engineering, and environmental remediation. A comprehensive approach has been developed toward the agro-industrial management of avocado (Persea americana) biomass waste, which can be transformed into high-value-added products to mitigate global warming, save non-renewable energy, and contribute to health and science. Therefore, this work presents a comprehensive review on avocado fruit waste biorefinery and its possible applications as biofuel, as drugs, as bioplastics, in the environmental field, and in emerging nanotechnological opportunities for economic and scientific growth.
ABSTRACT
Innate and adaptive immune responses lead to wound healing by regulating a complex series of events promoting cellular cross-talk. An inflammatory response is presented with its characteristic clinical symptoms: heat, pain, redness, and swelling. Some smart thermo-responsive polymers like chitosan, polyvinylpyrrolidone, alginate, and poly(ε-caprolactone) can be used to create biocompatible and biodegradable scaffolds. These processed thermo-responsive biomaterials possess 3D architectures similar to human structures, providing physical support for cell growth and tissue regeneration. Furthermore, these structures are used as novel drug delivery systems. Locally heated tumors above the polymer lower the critical solution temperature and can induce its conversion into a hydrophobic form by an entropy-driven process, enhancing drug release. When the thermal stimulus is gone, drug release is reduced due to the swelling of the material. As a result, these systems can contribute to the wound healing process in accelerating tissue healing, avoiding large scar tissue, regulating the inflammatory response, and protecting from bacterial infections. This paper integrates the relevant reported contributions of bioengineered scaffolds composed of smart thermo-responsive polymers for drug delivery applications in wound healing. Therefore, we present a comprehensive review that aims to demonstrate these systems' capacity to provide spatially and temporally controlled release strategies for one or more drugs used in wound healing. In this sense, the novel manufacturing techniques of 3D printing and electrospinning are explored for the tuning of their physicochemical properties to adjust therapies according to patient convenience and reduce drug toxicity and side effects.
Subject(s)
Biocompatible Materials/chemistry , Delayed-Action Preparations/administration & dosage , Drug Delivery Systems/methods , Polymers/chemistry , Wound Healing/drug effects , Animals , Biomedical Engineering/methods , Bioprinting/methods , Delayed-Action Preparations/pharmacokinetics , Disease Models, Animal , Drug Liberation , Hot Temperature , Humans , Hydrogels/chemistry , Hydrophobic and Hydrophilic Interactions , Printing, Three-DimensionalABSTRACT
Biosensors are measurement devices that can sense several biomolecules, and are widely used for the detection of relevant clinical pathogens such as bacteria and viruses, showing outstanding results. Because of the latent existing risk of facing another pandemic like the one we are living through due to COVID-19, researchers are constantly looking forward to developing new technologies for diagnosis and treatment of infections caused by different bacteria and viruses. Regarding that, nanotechnology has improved biosensors' design and performance through the development of materials and nanoparticles that enhance their affinity, selectivity, and efficacy in detecting these pathogens, such as employing nanoparticles, graphene quantum dots, and electrospun nanofibers. Therefore, this work aims to present a comprehensive review that exposes how biosensors work in terms of bacterial and viral detection, and the nanotechnological features that are contributing to achieving a faster yet still efficient COVID-19 diagnosis at the point-of-care.
Subject(s)
Bacteria/genetics , Biosensing Techniques/methods , Viruses/genetics , Animals , COVID-19/diagnosis , COVID-19/virology , Humans , Nanotechnology/methods , Pandemics/prevention & control , SARS-CoV-2/geneticsABSTRACT
En este estudio se prepararon y caracterizaron microcápsulas híbridas del conjugado de polifenoles derivados de la lignina proveniente de la cáscara de piña, y el quitosano obtenido a partir de la quitina de la cáscara del camarón; ambos materiales fueron obtenidos como residuos de la industria agropecuaria y pesquería de camarón de Costa Rica. Con el objetivo de preparar compuestos fenólicos derivados de la lignina, y utilizarlos en la síntesis de las microcápsulas, se realizó la hidrólisis enzimática de la misma en un reactor a presión atmosférica a un pH de 6.8, en buffer de citrato 1 M, durante 6 h a 37ºC. Las enzimas utilizadas fueron extraídas de los cultivos de hongos de Gloeophyllum trabeum (Pers.) Murrill y Phanerochae chrysosporiumin Burdsall. Para la obtención del quitosano se realizó la desacetilación alcalina a partir de exoesqueletos del camarón Heterocarpus vicarius Fazon. Para la preparación de las microcápsulas se empleó una disolución de quitosano en ácido acético, el cual fue mezclado con una disolución acuosa del producto obtenido de la hidrólisis de la lignina y luego añadido a una disolución de vaselina para microemulsionar. Posteriormente, se agregó el glutaraldehído como agente entrecruzante. Se obtuvieron microcápsulas con tamaños entre 5 y 10 µm. Estas microcápsulas son un material promisorio ya que, mediante la formación del complejo, se puede aumentar la solubilidad del quitosano y estabilizar los polifenoles, manteniendo así sus propiedades antioxidantes. Los resultados preliminares obtenidos en esta investigación, muestran el potencial de este material para el encapsulamiento de fármacos y pesticidas.
Hybrid microcapsules of the conjugate of polyphenols derived from lignin were prepared and characterized. They were obtained from pineapple peel and chitin from shrimp shell from agroindustry or shrimp fishery of Costa Rica. The phenolic compounds were obtained by hydrolysis of lignin, using the enzyme derivatives from the fungus culture of Gloeophyllum trabeum (Pers.) Murrill and Phanerochaete chrysosporium Burdsall. The reaction was carried out in a reactor with atmospheric pressure, pH 6.8, with a citrate buffer of 1M, for 6 hours at 37°C. The chitosan was obtained by alkaline deacetylation of the Heterocarpus vicarious Fazon, shrimp exoskeletons. Microcapsules were prepared mixing a solution of chitosan dissolved in acetic acid and a solution of polyphenol derivatives from lignin. Afterwards, they were added to a vaseline aqueous solution for the microemulsion formation and glutaraldehyde was added as a crosslinking agent. Microcapsules with sizes between 5 to 10 µm were obtained. These microcapsules are a promising material to increase chitosan solubility and for preventing the oxidation of polyphenols. The preliminary results obtained in this research show the potential of this material for the encapsulation of drugs and pesticides.