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1.
Nat Commun ; 10(1): 2566, 2019 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-31189915

RESUMO

There is clinical and scientific interest in developing local anesthetics with prolonged durations of effect from single injections. The need for such is highlighted by the current opioid epidemic. Site 1 sodium channel blockers such as tetrodotoxin (TTX) are extremely potent, and can provide very long nerve blocks but the duration is limited by the associated systemic toxicity. Here we report a system where slow release of TTX conjugated to a biocompatible and biodegradable polymer, poly(triol dicarboxylic acid)-co-poly(ethylene glycol) (TDP), is achieved by hydrolysis of ester linkages. Nerve block by the released TTX is enhanced by administration in a carrier with chemical permeation enhancer (CPE) properties. TTX release can be adjusted by tuning the hydrophilicity of the TDP polymer backbone. In vivo, 1.0-80.0 µg of TTX released from these polymers produced a range of durations of nerve block, from several hours to 3 days, with minimal systemic or local toxicity.


Assuntos
Anestésicos Locais/administração & dosagem , Portadores de Fármacos/química , Bloqueio Nervoso/métodos , Bloqueadores dos Canais de Sódio/administração & dosagem , Tetrodotoxina/administração & dosagem , Anestesia Local/métodos , Anestésicos Locais/farmacocinética , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/toxicidade , Plásticos Biodegradáveis/química , Plásticos Biodegradáveis/toxicidade , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Preparações de Ação Retardada/administração & dosagem , Portadores de Fármacos/toxicidade , Composição de Medicamentos/métodos , Avaliação Pré-Clínica de Medicamentos , Liberação Controlada de Fármacos , Masculino , Camundongos , Permeabilidade , Ratos , Ratos Sprague-Dawley , Nervo Isquiático/efeitos dos fármacos , Bloqueadores dos Canais de Sódio/farmacocinética , Tetrodotoxina/farmacocinética , Fatores de Tempo , Resultado do Tratamento
2.
Mar Pollut Bull ; 142: 15-24, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31232288

RESUMO

There is a reasonably extensive body of literature recording mass loss of polyhydroxyalkanoates (PHAs) (a class of biodegradable plastics) in the natural marine environment. However, to date, this research has been very disparate. Thus, it remains unclear what the timeframe for the biodegradation of such marine biodegradable plastics actually is. The aim of this work was to determine the rate of biodegradation of PHA in the marine environment and apply this to the lifetime estimation of PHA products. This provides the clarification required as to what 'marine biodegradation of PHA' means in practicality and allows the risks and benefits of using PHA to be transparently discussed. It was determined that the mean rate of biodegradation of PHA in the marine environment is 0.04-0.09 mg·day-1·cm-2 (p = 0.05) and that, for example, a PHA water bottle could be expected to take between 1.5 and 3.5 years to completely biodegrade.


Assuntos
Plásticos Biodegradáveis/química , Biodegradação Ambiental , Poli-Hidroxialcanoatos/química , Oceanos e Mares
3.
J Sci Food Agric ; 99(12): 5508-5515, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31099416

RESUMO

BACKGROUND: Biodegradable films from basil seed mucilage (BSM) were formed and modified with several di-carboxylic acid crosslinkers; i.e. tartaric acid (TA), malic acid (MA) and succinic acid (SA) with varying acidity and chemical structures, to enhance mechanical properties and water barrier ability. Basil seeds have a reasonable mucilage content and valuable properties; thus, it has the potential to develop valuable new biodegradable films. RESULT: We characterized BSM films with the three crosslinkers using Fourier-transform infrared (FTIR) spectra and observed a 1730 cm-1 CO stretching peak, which confirmed ester linkage between the mucilage and crosslinkers. The crosslinked films showed higher gel fraction than native films. The crosslinked films showed better swelling and water vapor permeability with SA than with TA and MA. Crosslinking led to significant improvement in strain at maximum load. Further, the stress maximum load was comparable to that of commercial low-density polyethylene (LDPE) film. Crosslinked films showed additional homogeneous morphology and an increase in thermal degradation temperatures. CONCLUSION: Crosslinking with dicarboxylic acids improved all the key properties of BSM films, including excellent stress and strain at maximum load, improved barrier capability and thermal properties. Thus, these films showed good potential as biodegradable films, especially for food packaging. © 2019 Society of Chemical Industry.


Assuntos
Embalagem de Alimentos/instrumentação , Ocimum basilicum/química , Extratos Vegetais/química , Mucilagem Vegetal/química , Plásticos Biodegradáveis/química , Permeabilidade , Sementes/química , Temperatura Ambiente
4.
Carbohydr Polym ; 216: 189-196, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31047056

RESUMO

In this study, the composite of carboxymethyl cellulose (CMC) film modified with gelatin and TiO2-Ag nanoparticles (CMC/Gel/TiO2-Ag) was prepared and some properties of synthesized film including physicochemical and photocatalytic properties were investigated. FT-IR results showed that new interactions between the film components were created. Scanning electron microscopy (SEM) results showed that the TiO2-Ag particles with 50-100 nm distributed in the CMC/Gelatin film. The results of the mechanical test showed that the TiO2-Ag nanoparticles at low concentrations increased tensile strength (TS) and decreased strain to break (STB), but with increasing nanoparticles concentrations, TS decreased and STB increased. Photocatalytic study showed that the prepared CMC/Gel/TiO2-Ag film has good photocatalytic property. Gas chromatography was used to study photocatalytic effects of film. Increasing TiO2-Ag nano particles on the film increases the photocatalytic activity of films against NH3, ethanol and benzene.


Assuntos
Plásticos Biodegradáveis/química , Carboximetilcelulose Sódica/química , Gelatina/química , Nanopartículas Metálicas/química , Prata/química , Titânio/química , Amônia/química , Benzeno/química , Plásticos Biodegradáveis/síntese química , Plásticos Biodegradáveis/efeitos da radiação , Carboximetilcelulose Sódica/síntese química , Carboximetilcelulose Sódica/efeitos da radiação , Catálise , Módulo de Elasticidade , Etanol/química , Gelatina/síntese química , Gelatina/efeitos da radiação , Luz , Membranas Artificiais , Nanopartículas Metálicas/efeitos da radiação , Nanocompostos/química , Nanocompostos/efeitos da radiação , Permeabilidade , Prata/efeitos da radiação , Vapor , Resistência à Tração , Titânio/efeitos da radiação , Água/química
5.
Carbohydr Polym ; 216: 54-62, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31047082

RESUMO

Biodegradable, antimicrobial, and semiconducting cellulosic composite was synthesized by in-situ polymerization of polyaniline in the presence of cellulose. The cobalt ferrite nanoparticles (CFO-NPs) were added during the polymerization process to acquire this composite magnetic property. The CFO-NPs were prepared by sol-gel method with average particles size less than 50 nm. The nanocomposites were characterized by Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX). In addition, their magnetic, dielectric constant, dielectric loss, and conductivity behaviors were studied. The magnetization (Ms) and conductivity increased up to 3.7 emu/g and 3.5 × 10-3 S/cm, respectively, with increasing CFO-NPs content. The prepared electromagnetic nanocomposite exhibits highly efficient biodegradability and antimicrobial activity against Escherichia coli, Bacillus subtilis, and Candida albicans. The antimicrobial activity increased with increasing CFO-NPs while the biodegradability decreased.


Assuntos
Compostos de Anilina/farmacologia , Celulose/farmacologia , Cobalto/farmacologia , Compostos Férricos/farmacologia , Nanocompostos/química , Nanopartículas/química , Compostos de Anilina/síntese química , Compostos de Anilina/química , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Antifúngicos/síntese química , Antifúngicos/química , Antifúngicos/farmacologia , Bacillus subtilis/efeitos dos fármacos , Plásticos Biodegradáveis/síntese química , Plásticos Biodegradáveis/química , Plásticos Biodegradáveis/farmacologia , Candida albicans/efeitos dos fármacos , Celulose/análogos & derivados , Celulose/síntese química , Cobalto/química , Condutividade Elétrica , Escherichia coli/efeitos dos fármacos , Compostos Férricos/síntese química , Compostos Férricos/química , Fenômenos Magnéticos , Tamanho da Partícula
6.
J Sci Food Agric ; 99(10): 4825-4832, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-30977138

RESUMO

BACKGROUND: The use of superabsorbent materials in horticulture has spread recently. These materials, which can retain water and release it as crops need it, have strong advantages such as the efficient use of water in periods of drought. However, these materials are made of synthetic polymers, which present problems of degradability and, sometimes, toxicity. For this reason, the main objective of this work is the development of biodegradable superabsorbent bioplastic (SAB) matrices using a soy protein isolate (SPI) as raw material. Zinc is also incorporated into these bioplastic matrices as an essential micronutrient for plants, to increase their added value. RESULTS: The incorporation of zinc chelated with 2,2',2″,2‴-(Ethene-1,2-diyldinitrilo)tetraacetic acid (Zn EDTA) (a salt with which the micronutrient is incorporated) into soy protein-based bioplastic matrices improved their superabsorbent capacity and provided a controlled release of water and nutrients to the crops. CONCLUSIONS: The results show the strong potential for the use of these bioplastic matrices in horticulture as superabsorbent materials that can release nutrients in a controlled manner. © 2019 Society of Chemical Industry.


Assuntos
Plásticos Biodegradáveis/química , Proteínas de Soja/química , Zinco/química , Adsorção , Plásticos Biodegradáveis/síntese química , Biotecnologia , Jardins , Micronutrientes/química , Água/química
7.
ACS Appl Mater Interfaces ; 11(19): 17270-17282, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30977624

RESUMO

Transdermal administration via skin appendages enables both localized and systemic drug delivery, as well as minimizes incidental toxicity. However, the design of an appropriate effective method for clinical use remains challenging. Here, we introduce calcium carbonate-based carriers for the transdermal transportation of bioactive substances. The proposed system presents easily manufacturable biodegradable particles with a large surface area enabling a high payload ability. Topical application of submicron porous CaCO3 particles in rats followed by the therapeutic ultrasound treatment results in their deep penetration through the skin along with plentiful filling of the hair follicles. Exploiting the loading capacity of the porous particles, we demonstrate efficient transportation of a fluorescent marker along the entire depth of the hair follicle down the bulb region. In vivo monitoring of the carrier degradation reveals the active dissolution/recrystallization of CaCO3 particles, resulting in their total resorption within 12 days. The proposed particulate system serves as an intrafollicular depot for drug storage and prolonged in situ release over this period. The urinary excretion profile proves the systemic absorption of the fluorescent marker. Hence, the elaborated transdermal delivery system looks promising for medical applications. The drug delivery to different target regions of the hair follicle may contribute to regenerative medicine, immunomodulation, and treatment of various skin disorders. In the meantime, the systemic uptake of the transported drug opens an avenue for prospective delivery routes beyond the scope of dermatology.


Assuntos
Plásticos Biodegradáveis/farmacologia , Carbonato de Cálcio/farmacologia , Portadores de Fármacos/farmacologia , Sistemas de Liberação de Medicamentos , Administração Cutânea , Animais , Plásticos Biodegradáveis/química , Carbonato de Cálcio/química , Portadores de Fármacos/química , Folículo Piloso/efeitos dos fármacos , Humanos , Ratos , Pele/efeitos dos fármacos
8.
Int J Pharm ; 561: 244-264, 2019 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-30851391

RESUMO

Nanomedicines are now considered as the new-generation medication in the current era mainly because of their features related to nano size. The efficacy of many drugs in their micro/macro formulations is shown to have poor bioavailability and pharmacokinetics after oral administration. To overcome this predicament, use of natural/synthetic biodegradable polymeric nanoparticles (NPs) have gained prominence in the field of nanomedicine for targeted drug delivery to improve biocompatibility, bioavailability, safety, enhanced permeability, better retention time and lower toxicity. For drug delivery, it is essential to have biodegradable nanoparticle formulations for safe and efficient transport and release of drug at the intended site. Moreover, depending on the target organ, a suitable biodegradable polymer can be selected as the drug-carrier for target specific as well as for sustained drug delivery. The aim of this review is to present the current status and scope of natural biodegradable polymers as well as some emerging polymers with special characteristics as suitable carriers for drug delivery applications. The most widely preferred preparation methods are discussed along with their characterization using different analytical techniques. Further, the review highlights significant features of methods developed using natural polymers for drug entrapment and release studies.


Assuntos
Plásticos Biodegradáveis/química , Sistemas de Liberação de Medicamentos/métodos , Nanopartículas/química , Polímeros/química
9.
Int J Pharm ; 561: 236-243, 2019 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-30853484

RESUMO

While vascular endothelial growth factor (VEGF) is an acknowledged potent pro-angiogenic agent there is a need to deliver it at an appropriate concentration for several days to achieve angiogenesis. The aim of this study was to produce microspheres of biodegradable polylactic-co-glycolic acid (PLGA) tailored to achieve sustained release of VEGF at an appropriate concentration over seven days, avoiding excessive unregulated release of VEGF that has been associated with the formation of leaky blood vessels. Several formulations were examined to produce microspheres loaded with both human serum albumin (HSA) and VEGF to achieve release of VEGF between 3 and 10 ng per ml for seven days to match the therapeutic window desired for angiogenesis. In vitro experiments showed an increase in endothelial cell proliferation in response to microspheres bearing VEGF. Similarly, when microspheres containing VEGF were added to the chorionic membrane of fertilised chicken eggs, there was an increase in the development of blood vessels over seven days in response, which was significant for microspheres bearing VEGF and HSA, but not VEGF alone. There was an increase in both blood vessel density and branching - both signs of proangiogenic activity. Further, there was clearly migration of cells to the VEGF loaded microspheres. In summary, we describe the development of an injectable delivery vehicle to achieve spatiotemporal release of physiologically relevant levels of VEGF for several days and demonstrate the angiogenic response to this. We propose that such a treatment vehicle would be suitable for the treatment of ischemic tissue or wounds.


Assuntos
Liberação Controlada de Fármacos , Microesferas , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Albumina Sérica/química , Fator A de Crescimento do Endotélio Vascular/química , Animais , Plásticos Biodegradáveis/química , Proliferação de Células/fisiologia , Galinhas , Córion/irrigação sanguínea , Preparações de Ação Retardada/química , Composição de Medicamentos/métodos , Células Endoteliais/fisiologia , Humanos , Neovascularização Fisiológica/efeitos dos fármacos , Fator A de Crescimento do Endotélio Vascular/farmacologia
10.
Eur J Pharm Biopharm ; 139: 142-152, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30902733

RESUMO

Nifedipine and nicardipine loaded PLGA extrudates have a great potential to prevent cerebral vasospasms after subarachnoid hemorrhage or surgical clipping of aneurysm. A constant release over approx. two weeks is desired. Although in vivo studies on humans have been reported, there is limited knowledge about the release kinetics and the underlying mechanisms. Therefore, nifedipine and nicardipine loaded PLGA implants with different drug loads were manufactured by extrusion and investigated. In addition to the measurements of the release kinetics, GPC, DSC, X-ray diffraction and light microscopic investigations were performed for a detailed characterization. The water uptake and polymer erosion studies showed an initial lag phase of 5-7 days and an acceleration of both processes thereafter. With 5% loaded implants a higher drug release compared to 10% drug loaded polymers could be achieved and not only the relative amount of drug release (% of loaded drug), but surprisingly also the absolute amount of the released drug increased. The drugs were initially in an amorphous state. For nifedipine, formation of drug crystals with time has been observed by light microscopy and X-ray diffraction. The analysis of the drug content in the degrading polymer showed a very large increase from 10% to about 20% (nifedipine) and over 50% (nicardipine). In contrast, no or only a moderate increase of the drug content occurred for initially 5% loaded polymer implants. We postulate that water penetration and polymer degradation induced changes of the microenvironment lead to supersaturated systems. A supersaturated state is faster reached for polymers with higher drug load and therefore, drug precipitation takes place at earlier time points. As a result, drug release might be incomplete for poorly soluble drugs and paradoxically, the total amount of drug release might be higher for systems with a lower drug load. Drug release is initially controlled by the PLGA matrix, but later by the dissolution kinetics of the precipitated drug which are very slow for poorly soluble drugs according to the Noyes-Whitney equation.


Assuntos
Bloqueadores dos Canais de Cálcio/farmacocinética , Portadores de Fármacos/química , Implantes de Medicamento/farmacocinética , Liberação Controlada de Fármacos , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Plásticos Biodegradáveis/química , Bloqueadores dos Canais de Cálcio/administração & dosagem , Varredura Diferencial de Calorimetria , Composição de Medicamentos/métodos , Implantes de Medicamento/administração & dosagem , Humanos , Nicardipino/administração & dosagem , Nicardipino/farmacocinética , Nifedipino/administração & dosagem , Nifedipino/farmacocinética , Solubilidade , Difração de Raios X
11.
Eur J Pharm Biopharm ; 139: 115-122, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30905777

RESUMO

Characterization of controlled release formulations used for intra-articular (IA) drug administration is challenging. Bio-relevant synovial fluids (BSF), containing physiologically relevant amounts of hyaluronic acid, phospholipids and proteins, were recently proposed to simulate healthy and osteoarthritic conditions. This work aims to evaluate the performance of different controlled release formulations of methylprednisolone (MP) for IA administration, under healthy and disease states simulated conditions. Microspheres differed in grade of poly(lactide-co-glycolide) and in the theoretical drug content (i.e. 23 or 30% w/w). Their performance was compared with the commercially available suspension of MP acetate (MPA). Under osteoarthritic state simulated condition, proteins increased the MPA release and reduced the MPA hydrolysis rate, over 48 h. Regarding microspheres, the release patterns over 40 days were significantly influenced by the composition of BSF. The pattern of the release mechanism and the amount released was affected by the presence of proteins. Protein concentration affected the release and the concentration used is critical, particularly given the relevance of the concentrations to target patient populations, i.e. patients with osteoarthritis.


Assuntos
Portadores de Fármacos/química , Liberação Controlada de Fármacos , Glucocorticoides/farmacocinética , Metilprednisolona/farmacocinética , Líquido Sinovial/metabolismo , Plásticos Biodegradáveis/química , Preparações de Ação Retardada/administração & dosagem , Preparações de Ação Retardada/farmacocinética , Glucocorticoides/administração & dosagem , Humanos , Injeções Intra-Articulares , Metilprednisolona/administração & dosagem , Microesferas , Osteoartrite/tratamento farmacológico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química
12.
Carbohydr Polym ; 207: 180-190, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30599998

RESUMO

Tissue adhesion is one of the most common complications after surgery (especially after abdominal surgery), causing notable influences after the damaged tissue has healed. A physical barrier placed between the wound site and the adjacent tissues is a convenient and highly effective technique to minimize or prevent abdominal adhesions. In this work, the N, O-carboxymethyl chitosan/oxidized regenerated cellulose (N, O-CS/ORC) composite gauze was prepared. The N, O-CS/ORC composite gauze is degradable; in addition, the gauze exhibits excellent antimicrobial functionality against S. aureus and E. coli bacteria. Moreover, the notable hemostatic efficacy of the N, O-CS/ORC composite gauze was confirmed in rabbit livers/ears as models. The results showed that the N, O-CS/ORC composite gauze is nontoxic toward normal cells and can restrain the adhesion of fibroblast cells, thereby indicating its potential use in preventing tissue adhesion. In addition, the rat models for abdominal defect-cecum abrasion were used to evaluate the efficacy of N, O-CS/ORC composite gauze in preventing tissue adhesions after surgery. The results indicated that the N, O-CS/ORC composite gauze can significantly prevent postsurgical peritoneal adhesions. Finally, the potential anti-adhesion mechanism of the N, O-CS/ORC composite gauze, which may attribute to the combination of barrier function and instinct activity of N, O-CS and ORC, was investigated.


Assuntos
Antibacterianos/farmacologia , Plásticos Biodegradáveis/farmacologia , Celulose/farmacologia , Quitosana/farmacologia , Hemostáticos/farmacologia , Implantes Absorvíveis , Animais , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/toxicidade , Bandagens , Plásticos Biodegradáveis/síntese química , Plásticos Biodegradáveis/química , Plásticos Biodegradáveis/toxicidade , Celulose/síntese química , Celulose/química , Celulose/toxicidade , Quitosana/síntese química , Quitosana/química , Quitosana/toxicidade , Escherichia coli/efeitos dos fármacos , Feminino , Hemostáticos/síntese química , Hemostáticos/química , Hemostáticos/toxicidade , Células Endoteliais da Veia Umbilical Humana , Humanos , Masculino , Camundongos , Células NIH 3T3 , Coelhos , Ratos Sprague-Dawley , Staphylococcus aureus/efeitos dos fármacos , Aderências Teciduais/prevenção & controle
13.
Carbohydr Polym ; 207: 447-459, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30600028

RESUMO

With the increasing consumption of global fossil energy and environmental pollution, the development of green renewable energy and efficient energy storage technology become an urgent problem to solve. Supercapacitors have drawn a great interest for use in wearable electronic devices due to their portability and stable performance. The electrode is very important when preparing a high-performance flexible supercapacitor, which requires good electrochemical performance and flexibility. Graphene and nanocellulose are excellent flexible electrode material for supercapacitors, and nanocellulose is often used as a substrate material for electronic devices because of its good biodegradability, mechanical flexibility and chemical reactivity. In this work, the structure design and assembly method of the nanocellulose-graphene composite materials used for flexible supercapacitors are reviewed. The mechanical flexibility, specific capacitance, electrochemical performance, cyclic stability, renewability and biodegradability are taken into account, so as to evaluate the performance of the composite materials and to better assess the merits of this material with respect to real applications.


Assuntos
Celulose/química , Grafite/química , Nanocompostos/química , Nanopartículas/química , Plásticos Biodegradáveis/química , Capacitância Elétrica , Fontes de Energia Elétrica , Desenho de Equipamento , Hidrogéis/química , Maleabilidade
14.
ACS Appl Mater Interfaces ; 11(10): 9786-9793, 2019 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-30689338

RESUMO

Although biodegradable membranes are essential for effective bone repair, severe loss of mechanical stability because of rapid biodegradation, soft tissue invasion, and excessive immune response remain intrinsically problematic. Inspired by the exoskeleton-reinforcing strategy found in nature, we have produced a Ti-infiltrated chitin nanofibrous membrane. The membrane employs vapor-phase infiltration of metals, which often occurs during metal oxide atomic layer deposition (ALD) on organic substrates. This metal infiltration manifests anomalous mechanical improvement and stable integration with chitin without cytotoxicity and immunogenicity. The membrane exhibits both impressive toughness (∼13.3 MJ·m-3) and high tensile strength (∼55.6 MPa), properties that are often mutually exclusive. More importantly, the membrane demonstrates notably enhanced resistance to biodegradation, remaining intact over the course of 12 weeks. It exhibits excellent osteointegrative performance and suppresses the immune response to pathogen-associated molecular pattern molecules indicated by IL-1ß, IL-6, and granulocyte-macrophage colony-stimulating factor expression. We believe the excellent chemico-biological properties achieved with ALD treatment can provide insight for synergistic utilization of the polymers and ALD in medical applications.


Assuntos
Plásticos Biodegradáveis/química , Quitina/química , Nanofibras/química , Titânio/química , Plásticos Biodegradáveis/uso terapêutico , Regeneração Óssea/efeitos dos fármacos , Quitina/uso terapêutico , Humanos , Imunidade Celular/efeitos dos fármacos , Teste de Materiais , Membranas Artificiais , Nanofibras/uso terapêutico , Óxidos/química , Óxidos/uso terapêutico , Resistência à Tração , Titânio/uso terapêutico
15.
Biopolymers ; 110(5): e23250, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30589085

RESUMO

In this study proteins extracted from prepupae of Hermetia illucens, also known as black soldier fly, are investigated as promising base for a new type of bioplastics for agricultural purposes. Design of experiments techniques are employed to perform a rational study on the effects of different combination of glycerol as plasticizer, citric acid as cross-linking agent and distilled water as solvent on the capability of proteins to form a free-standing film through casting technique, keeping as fixed the quantity of proteins. Glycerol shows interesting properties as plasticizer contributing to the formation of homogenous and free-standing film. Moreover, mechanical and thermal characterizations are performed to estimate the effect of increasing amounts of proteins on the final properties and thickness of the specimens. Proteins derived from H. illucens can be successfully employed as base for bioplastics to be employed for agricultural purposes.


Assuntos
Plásticos Biodegradáveis , Dípteros/química , Proteínas de Insetos/química , Membranas Artificiais , Animais , Plásticos Biodegradáveis/síntese química , Plásticos Biodegradáveis/química , Pupa/química
16.
J Sci Food Agric ; 99(6): 3134-3141, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30536769

RESUMO

BACKGROUND: Starch is an alternative material for the production of biodegradable plastics; however, native starches have drawbacks due to their hydrophilic nature. Chemical modifications such as acetylation and crosslinking are used to broaden the potential end-uses of starch. Dual modification of starches increases their functionality compared to that of starches with similar single modifications. In this study, a dual-modified potato starch (acetylated and crosslinked) was used to produce films by casting. RESULTS: Changes in the arrangement of the amylopectin double helices of dual-modified starch were evident from X-ray diffraction patterns, pasting profiles and thermal properties. The degree of substitution for acetyl groups was low (0.058 ± 0.006) because crosslinking dominated acetylation. Modified starch film had higher elongation percentage (82.81%) than its native counterpart (57.4%), but lower tensile strength (3.51 MPa for native and 2.17 MPa for dual-modified) and lower crystallinity in fresh and stored films. The sorption isotherms indicated that the dual modification decreased the number of reactive sites for binding water, resulting in a reduction in the monolayer value and a decrease in the solubility and water vapor permeability. CONCLUSIONS: Dual modification of starch may be a feasible option for improving the properties of biodegradable starch films. © 2018 Society of Chemical Industry.


Assuntos
Plásticos Biodegradáveis/química , Extratos Vegetais/química , Solanum tuberosum/química , Amido/química , Acetilação , Reagentes para Ligações Cruzadas/química , Permeabilidade , Solubilidade , Resistência à Tração , Difração de Raios X
17.
Int J Biol Macromol ; 125: 999-1007, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30572052

RESUMO

Two polysaccharides (PS), gum arabic (GA) and sodium alginate (SA), and whey protein concentrate (WPC) were used to design bio-based films at two ratios (RPS:WPC, 1:2 and 1:3). The effects of PS, RPS:WPC and WPC thermal treatment (unheated vs. aggregate) were determined on films characteristics. Film-forming dispersions were tested using different complementary techniques: UV-Vis spectroscopy, electrophoretic mobility, bulk rheology and confocal microscopy. PS exhibited weak associations with proteins. However, this behavior was more significative in SA/WPC systems. Rheological and optical characteristics of filmogenic suspensions were influenced by PS, RPS:WPC and WPC heat treatment. Apparent viscosity values for SA/WPC systems were 80-250 times higher than the ones obtained for GA/WPC systems. Furthermore, thickness, moisture absorption, contact angle and mechanical properties were also affected by the film design factors. GA/WPC-aggregates films showed lesser moisture absorption; however, they have higher surface polarity than those made with SA/WPC-aggregates. Moreover, SA/WPC-aggregates systems provided stronger films in comparison with the GA/WPC-aggregates ones. In addition, mechanical properties were also affected by RPS:WPC and WPC treatment. It was observed that denatured WPC and 1:3 RPS:WPC produced weaker mechanical features. Results provide useful information for the design of bio-based mixed films with tailor-made properties.


Assuntos
Alginatos/química , Plásticos Biodegradáveis/química , Goma Arábica/química , Proteínas do Soro do Leite/química , Armazenamento de Alimentos/instrumentação , Humanos , Teste de Materiais , Membranas Artificiais , Reologia , Viscosidade , Molhabilidade
18.
ACS Appl Mater Interfaces ; 11(3): 2782-2789, 2019 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-30584767

RESUMO

Simplifying synthesis and administration process, improving photothermal agents' accumulation in tumors, and ensuring excellent biocompatibility and biodegradability are keys to promoting the clinical application of photothermal therapy. However, current photothermal agents have great difficulties in meeting the requirements of clinic drugs from synthesis to administration. Herein, we reported the in situ formation of a Ca2+/Mg2+ stimuli-responsive ICG-alginate hydrogel in vivo for localized tumor photothermal therapy. An ICG-alginate hydrogel can form by the simple introduction of Ca2+/Mg2+ into ICG-alginate solution in vitro, and the widely distributed divalent cations in organization in vivo enabled the in situ fabrication of the ICG-alginate hydrogel without the leakage of any agents by simple injection of ICG-alginate solution into the body of mice. The as-prepared ICG-alginate hydrogel not only owns good photothermal therapy efficacy and excellent biocompatibility but also exhibits strong ICG fixation ability, greatly benefiting the high photothermal agents' accumulation and minimizing the potential side effects induced by the diffusion of ICG to surrounding tissues. The in situ-fabricated ICG-alginate hydrogel was applied successfully in highly efficient PTT in vivo without obvious side effects. Besides, the precursor of the hydrogel, ICG and alginate, can be stored in a stable solid form, and only simple mixing and noninvasive injection are needed to achieve PTT in vivo. The proposed in situ gelation strategy using biocompatible components lays down a simple and mild way for the fabrication of high-performance PTT agents with the superiors in the aspects of synthesis, storage, transportation, and clinic administration.


Assuntos
Verde de Indocianina/uso terapêutico , Nanopartículas/química , Neoplasias/terapia , Fototerapia , Alginatos/química , Alginatos/farmacologia , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/uso terapêutico , Plásticos Biodegradáveis/síntese química , Plásticos Biodegradáveis/química , Plásticos Biodegradáveis/uso terapêutico , Corantes/química , Humanos , Hidrogel de Polietilenoglicol-Dimetacrilato/síntese química , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Verde de Indocianina/síntese química , Verde de Indocianina/química , Raios Infravermelhos , Nanopartículas/uso terapêutico , Neoplasias/patologia , Nanomedicina Teranóstica
19.
ACS Appl Mater Interfaces ; 11(3): 2768-2781, 2019 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-30589254

RESUMO

In this work, we reported the synthesis of an engineered novel nanocarrier composed of biodegradable charged polyester vectors (BCPVs) and graphene quantum dots (GQDs) for pancreatic cancer (MiaPaCa-2 cells) therapy applications. Such a nanocarrier was utilized to co-load doxorubicin (DOX) and small interfering ribonucleic acid (siRNA), resulting in the formation of GQD/DOX/BCPV/siRNA nanocomplexes. The resulting nanocomplexes have demonstrated high stability in physiologically mimicking media, excellent K-ras downregulation activity, and effective bioactivity inhibition for MiaPaCa-2 cells. More importantly, laser light was used to generate heat for the nanocomplexes via the photothermal effect to damage the cells, which was further employed to trigger the release of payloads from the nanocomplexes. Such triggered release function greatly enhanced the anticancer activity of the nanocomplexes. Preliminary colony formation study also suggested that GQD/DOX/BCPV/siRNA nanocomplexes are qualified carrier candidates in subsequent in vivo tests.


Assuntos
Grafite/química , Nanopartículas/química , Neoplasias Pancreáticas/terapia , Fototerapia , Plásticos Biodegradáveis/química , Plásticos Biodegradáveis/uso terapêutico , Sobrevivência Celular/efeitos dos fármacos , Doxorrubicina/química , Doxorrubicina/farmacologia , Grafite/uso terapêutico , Humanos , Luz , Neoplasias Pancreáticas/patologia , Polímeros/química , Pontos Quânticos/química , Pontos Quânticos/uso terapêutico
20.
Int J Mol Sci ; 19(8)2018 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-30042300

RESUMO

Polymer-based piezoelectric biomaterials have already proven their relevance for tissue engineering applications. Furthermore, the morphology of the scaffolds plays also an important role in cell proliferation and differentiation. The present work reports on poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV), a biocompatible, biodegradable, and piezoelectric biopolymer that has been processed in different morphologies, including films, fibers, microspheres, and 3D scaffolds. The corresponding magnetically active PHBV-based composites were also produced. The effect of the morphology on physico-chemical, thermal, magnetic, and mechanical properties of pristine and composite samples was evaluated, as well as their cytotoxicity. It was observed that the morphology does not strongly affect the properties of the pristine samples but the introduction of cobalt ferrites induces changes in the degree of crystallinity that could affect the applicability of prepared biomaterials. Young's modulus is dependent of the morphology and also increases with the addition of cobalt ferrites. Both pristine and PHBV/cobalt ferrite composite samples are not cytotoxic, indicating their suitability for tissue engineering applications.


Assuntos
Plásticos Biodegradáveis/química , Plásticos Biodegradáveis/farmacologia , Técnicas Eletroquímicas , Poliésteres/química , Engenharia Tecidual , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Fenômenos Químicos , Cobalto/química , Compostos Férricos/química , Humanos , Interações Hidrofóbicas e Hidrofílicas , Imãs , Teste de Materiais , Nanopartículas Metálicas/química , Camundongos , Osteoblastos , Porosidade , Tecidos Suporte
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