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2.
Molecules ; 29(12)2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38930901

RESUMO

This study presents fibers based on methacrylic acid-methyl methacrylate (Eudragit L100) as Cu(II) adsorbents, resulting in antimicrobial complexes. Eudragit L100, an anionic copolymer synthesized by radical polymerization, was electrospun in dimethylformamide (DMF) and ethanol (EtOH). The electrospinning process was optimized through a 22-factorial design, with independent variables (copolymer concentration and EtOH/DMF volume ratio) and three repetitions at the central point. The smallest average fiber diameter (259 ± 53 nm) was obtained at 14% w/v Eudragit L100 and 80/20 EtOH/DMF volume ratio. The fibers were characterized using scanning electron microscopy (SEM), infrared spectroscopy in attenuated total reflectance mode (FTIR-ATR), and differential scanning calorimetry (DSC). The pseudo-second-order mechanism explained the kinetic adsorption toward Cu(II). The fibers exhibited a maximum adsorption capacity (qe) of 43.70 mg/g. The DSC analysis confirmed the Cu(II) absorption, indicating complexation between metallic ions and copolymer networks. The complexed fibers showed a lower degree of swelling than the non-complexed fibers. The complexed fibers exhibited bacteriostatic activity against Gram-negative (Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus) bacteria. This study successfully optimized the electrospinning process to produce thin fibers based on Eudragit L100 for potential applications as adsorbents for Cu(II) ions in aqueous media and for controlling bacterial growth.


Assuntos
Cobre , Ácidos Polimetacrílicos , Cobre/química , Ácidos Polimetacrílicos/química , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Adsorção , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus/efeitos dos fármacos , Metacrilatos/química , Cinética , Varredura Diferencial de Calorimetria , Testes de Sensibilidade Microbiana
3.
Int J Biol Macromol ; 257(Pt 1): 128461, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38042320

RESUMO

Environmental pollution caused by non-biodegradable plastic pollutants adversely affects various ecosystems. This study proposes the development of novel functional and biodegradable films based on corn starch (CST) and pectin (PEC) containing zinc oxide nanoparticles (ZnONPs) from the casting method. The films exhibited processability, transparency, low water vapor permeation, and desirable mechanical properties for food packaging and coating applications. The ZnONPs acted as a plasticizer, enhancing the film elongation at the break, increasing the pec25-1 (PEC 25 wt% and ZnONPs 1 wt%) elongation from 79.85 to 162.32 %. The improved film elasticity supported by ZnONPs reduced the material stiffness. However, the films still demonstrated an average tensile strength (0.69 MPa) 17-fold higher than the tensile strength (0.04 MPa) of the non-biodegradable commercial film based on poly(vinyl chloride). Furthermore, the ZnONPs enhanced the UV-blocking capabilities of the films, leading to wettable materials with water contact angles lower than 90°. The films showed high biodegradation rates under natural disposal conditions. The results indicated that the pec25-1/ZnONPs film is a promising eco-friendly coating in food preservation due to its biodegradability, suitable mechanical properties, low water vapor permeability, and UV-blocking properties.


Assuntos
Nanopartículas , Óxido de Zinco , Pectinas , Vapor , Ecossistema , Embalagem de Alimentos/métodos , Amido
4.
J Funct Biomater ; 14(11)2023 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-37998123

RESUMO

Bacterial infections are a common mode of failure for medical implants. This study aims to develop antibacterial polyelectrolyte multilayer (PEM) coatings that contain a plant-derived condensed tannin polymer (Tanfloc, TAN) with inherent antimicrobial activity. Tanfloc is amphoteric, and herein we show that it can be used as either a polyanion or a polycation in PEMs, thereby expanding the possibility of its use in PEM coatings. PEMs are ordinarily formed using a polycation and a polyanion, in which the functional (ionic) groups of the two polymers are complexed to each other. However, using the amphoteric polymer Tanfloc with weakly basic amine and weakly acidic catechol and pyrogallol groups enables PEM formation using only one or the other of its functional groups, leaving the other functional group available to impart antibacterial activity. This work demonstrates Tanfloc-containing PEMs using multiple counter-polyelectrolytes including three polyanionic glycosaminoglycans of varying charge density, and the polycations N,N,N-trimethyl chitosan and polyethyleneimine. The layer-by-layer (LbL) assembly of PEMs was monitored using in situ Fourier-transform surface plasmon resonance (FT-SPR), confirming a stable LbL assembly. X-ray photoelectron spectroscopy (XPS) was used to evaluate surface chemistry, and atomic force microscopy (AFM) was used to determine the surface roughness. The LDH release levels from cells cultured on the Tanfloc-containing PEMs were not statistically different from those on the negative control (p > 0.05), confirming their non-cytotoxicity, while exhibiting remarkable antiadhesive and bactericidal properties against Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus), respectively. The antibacterial effects were attributed to electrostatic interactions and Tanfloc's polyphenolic nature. This work underscores the potential of Tanfloc as a versatile biomaterial for combating infections on surfaces.

5.
Int J Biol Macromol ; 253(Pt 5): 127087, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37769774

RESUMO

Given the environmental issues caused by the extensive use of conventional petroleum-based packaging, this work proposes functional films based on commercial κ-carrageenan (κc), poly(vinyl alcohol) (PVA), and gallic acid (GA) prepared by the "casting" method. Metallic ions in the κc composition stabilized the films, supporting processability and suitable mechanical properties. However, the incorporated GA amount (6.25 and 10 wt%) in the films created from an aqueous κc solution at 3.0 % wt/v (κc3) prevented crystalline domains in the resulting materials. The κc3/GA6.25 and κc3/GA10 films had less tensile strength (8.50 ± 0.61 and 10.28 ± 0.65 MPa) and high elongation at break (2.36 ± 0.16 and 1.19 ± 0.17 %) compared to the other samples, respectively. Low κc contents (κc2.5/GA6.25 and κc2.5/GA10) promoted stiff films and less permeability to water vapor (5.36 ± 0.51 and 3.76 ± 0.02 [×10-12 g(Pa × m × s)-1], respectively. The κc/GA weight ratio also influenced the film wettability, indicating water contact angles (WCAs) between 55 and 74°. The surface wettability implies a low oil permeability and high water swelling capacity of up to 1600 %. The κc/GA also played an essential role in the film's antimicrobial action against Staphylococcus aureus and Escherichia coli. Thus, the κc3/GA10 film showed suitable physical, chemical, and biological properties, having the potential to be applied as food coatings.


Assuntos
Ácido Gálico , Álcool de Polivinil , Carragenina/química , Álcool de Polivinil/química , Resistência à Tração , Permeabilidade , Escherichia coli , Embalagem de Alimentos/métodos
6.
Int J Biol Macromol ; 241: 124497, 2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37080405

RESUMO

Carboxymethylcellulose (CMC) and keratin nanoparticle (KNP) hydrogels were obtained, characterized, and applied as drug delivery systems (DDSs) for the first time. Lyophilized CMC/KNP mixtures containing 10, 25, and 50 wt% of KNPs were kept at 170 °C for 90 min to crosslink CMC chains through a solid-state reaction with the KNPs. The hydrogels were characterized by infrared spectroscopy, thermal analyses, X-ray diffraction, mechanical measurements, and scanning electron microscopy. The infrared spectra indicated the formation of ester and amide linkages between crosslinked CMC and KNPs. The elastic modulus of the hydrogel containing 10 wt% KNPs was 2-fold higher than that of the hydrogel containing 50 wt% KNPs. The mechanical properties influenced the hydrogel stability and water uptake. The anti-inflammatory prednisolone (PRED) drug was incorporated into the hydrogels, and the release mechanism was investigated. The hydrogels supported PRED release by drug desorption for approximately 360 h. A sustained release mechanism was achieved. The CMC/KNP and CMC/KNP/PRED hydrogels were cytocompatible toward mammalian cells. The CMC/KNP/PRED set imparted the highest cell viability after 7 days of incubation. This study showed a straightforward procedure to create DDSs (chemically crosslinked) based on polysaccharides and proteins for efficient PRED delivery.


Assuntos
Hidrogéis , Nanopartículas , Animais , Hidrogéis/química , Queratinas , Carboximetilcelulose Sódica/química , Prednisolona/farmacologia , Anti-Inflamatórios , Mamíferos
7.
Front Pharmacol ; 13: 854859, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35462891

RESUMO

Polymer-based nanocarriers require extensive knowledge of their chemistries to learn functionalization strategies and understand the nature of interactions that they establish with biological entities. In this research, the poly (ß-amino ester) (PßAE-447) was synthesized and characterized, aimed to identify the influence of some key parameters in the formulation process. Initially; PßAE-447 was characterized for aqueous solubility, swelling capacity, proton buffering ability, and cytotoxicity study before nanoparticles formulation. Interestingly, the polymer-supported higher cell viability than the Polyethylenimine (PEI) at 100 µg/ml. PßAE-447 complexed with GFP encoded plasmid DNA (pGFP) generated nanocarriers of 184 nm hydrodynamic radius (+7.42 mV Zeta potential) for cell transfection. Transfection assays performed with PEGylated and lyophilized PßAE-447/pDNA complexes on HEK-293, BEAS-2B, and A549 cell lines showed better transfection than PEI. The outcomes toward A549 cells (above 66%) showed the highest transfection efficiency compared to the other cell lines. Altogether, these results suggested that characterizing physicochemical properties pave the way to design a new generation of PßAE-447 for gene delivery.

8.
Int J Biol Macromol ; 193(Pt B): 1813-1822, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34774866

RESUMO

Biodegradable and eco-friendly adsorbents composed of natural carbohydrates have been used to replace carbon-based materials. This study presents a natural carbohydrate-based chitosan/pectin (CS/Pec) hydrogel adsorbent to remove Pb(II) from aqueous solutions. The physical CS/Pec hydrogel was prepared by blending aqueous CS and Pec solutions at 65 °C, preventing the use of toxic chemistries (crosslinking agents). The thermosensitive CS/Pec hydrogel was quickly created by cooling CS/Pec blend at room temperature. The used strategy created stable CS/Pec hydrogel against disintegration and water dissolution. The as-prepared hydrogel was characterized by infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The adsorbent had 1.688 mmol -COO- for each gram. These ionized sites bind Pb(II) ions, promoting their adsorption. The adsorption kinetic and equilibrium studies indicated that the Elovich and pseudo-second-order models adjusted well to the experimental data, respectively. The maximum removal capacities (qm) predicted by the Langmuir and Sips isotherms achieved 108.2 and 97.55 mg/g at 0.83 g/L adsorbent dosage (pH 4.0). The hydrogel/Pb(II) pair was characterized by scanning electron microscopy (SEM), X-ray dispersive energy (EDS), and differential scanning calorimetry (DSC). The chemisorption seems to play an essential role in the Pb(II) adsorption. Therefore, the adsorbent was not recovered, showing low potential for reusability.


Assuntos
Quitosana/química , Chumbo/química , Pectinas/química , Poluentes Químicos da Água/química , Purificação da Água
9.
Molecules ; 26(15)2021 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-34361681

RESUMO

Gelatin (GE), amino-functionalized polyphenolic tannin derivative (TN), and graphene oxide (GO) were associated to yield thermo- and pH-responsive hydrogels for the first time. Durable hydrogel assemblies for drug delivery purposes were developed using the photosensitizer methylene blue (MB) as a drug model. The cooling GE/TN blends provide brittle physical assemblies. To overcome this disadvantage, different GO contents (between 0.31% and 1.02% wt/wt) were added to the GE/TN blend at 89.7/10.3 wt/wt. FTIR and RAMAN spectroscopy analyses characterized the materials, indicating GO presence in the hydrogels. Incorporation studies revealed a total MB (0.50 mg/mL) incorporation into the GE/TN-GO hydrogel matrices. Additionally, the proposed systems present a mechanical behavior similar to gel. The GO presence in the hydrogel matrices increased the elastic modulus from 516 to 1650 Pa. SEM revealed that hydrogels containing MB present higher porosity with interconnected pores. Dissolution and swelling degree studies revealed less stability of the GE/TN-GO-MB hydrogels in SGF medium (pH 1.2) than SIF (pH 6.8). The degradation increased in SIF with the GO content, making the polymeric matrices more hydrophilic. MB release studies revealed a process controlled by Fickian diffusion. Our results point out the pH-responsible behavior of mechanically reinforced GE/TN-GO-MB hydrogels for drug delivery systems purposes.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Gelatina/química , Grafite/química , Hidrogéis/química , Azul de Metileno/administração & dosagem , Taninos/química , Temperatura de Transição , Materiais Biocompatíveis/química , Difusão , Liberação Controlada de Fármacos , Módulo de Elasticidade , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Transição de Fase , Porosidade
10.
Pharmaceutics ; 13(5)2021 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-33925380

RESUMO

Polysaccharide-based materials created by physical processes have received considerable attention for biomedical applications. These structures are often made by associating charged polyelectrolytes in aqueous solutions, avoiding toxic chemistries (crosslinking agents). We review the principal polysaccharides (glycosaminoglycans, marine polysaccharides, and derivatives) containing ionizable groups in their structures and cellulose (neutral polysaccharide). Physical materials with high stability in aqueous media can be developed depending on the selected strategy. We review strategies, including coacervation, ionotropic gelation, electrospinning, layer-by-layer coating, gelation of polymer blends, solvent evaporation, and freezing-thawing methods, that create polysaccharide-based assemblies via in situ (one-step) methods for biomedical applications. We focus on materials used for growth factor (GFs) delivery, scaffolds, antimicrobial coatings, and wound dressings.

11.
Int J Biol Macromol ; 183: 727-742, 2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-33915214

RESUMO

In this work free-standing gels formed from gellan gum (GG) by solvent evaporation are coated with polysaccharide-based polyelectrolyte multilayers, using the layer-by-layer approach. We show that PEMs composed of iota-carrageenan (CAR) and three different natural polycationic polymers have composition-dependent antimicrobial properties, and support mammalian cell growth. Cationic polymers (chitosan (CHT), N,N,N-trimethyl chitosan (TMC), and an amino-functionalized tannin derivative (TN)) are individually assembled with the anionic iota-carrageenan (CAR) at pH 5.0. PEMs (15-layers) are alternately deposited on the GG film. The GG film and coated GG films with PEMs are characterized by infrared spectroscopy with attenuated total reflectance (FTIR-ATR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and water contact angle (WCA) measurements. The TN/CAR coating provides a hydrophobic (WCA = 127°) and rough surface (Rq = 243 ± 48 nm), and the TMC/CAR coating provides a hydrophilic surface (WCA = 78°) with the lowest roughness (Rq = 97 ± 12 nm). Polymer coatings promote stability and durability of the GG film, and introduce antimicrobial properties against Gram-negative (Salmonella enteritidis) and Gram-positive (Staphylococcus aureus) bacteria. The films are also cytocompatible. Therefore, they have properties that can be further developed as wound dressings and food packaging.


Assuntos
Anti-Infecciosos/síntese química , Materiais Biocompatíveis/síntese química , Carragenina/química , Quitosana/química , Polissacarídeos Bacterianos/química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Embalagem de Alimentos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Interações Hidrofóbicas e Hidrofílicas , Microscopia de Força Atômica , Espectroscopia Fotoeletrônica , Polieletrólitos , Cicatrização
12.
Carbohydr Res ; 499: 108194, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33234262

RESUMO

Strategies for incorporating water-insoluble photosensitisers (PS) in drug delivery systems have been extensively studied. In this work, we evaluate the formation, characterisation, drug sorption studies, and cytotoxicity of chitosan (CHT)/chondroitin sulphate (CS) polyelectrolyte complexes (PECs) coated with polystyrene-block-poly(acrylic acid) (PS-b-PAA) nanoparticles (NPs) loaded with chloroaluminum phthalocyanine (AlClPc). The PECs were characterised by infrared spectroscopy (FTIR), differential scanning calorimetric (DSC), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The PS-b-PAA NPs on the PEC surface was confirmed by scanning electron microscopy (SEM). Additionally, optical images distinguished the PEC structures containing PS-b-PAA or PS-b-PAA/AlClPc from the unloaded PEC. Kinetic and equilibrium studies investigate the sorption capacity of the PEC/PS-b-PAA toward AlClPc. The encapsulation efficiency reached 95% at 190 µg mL-1 AlClPc after only 15 min. The Brunauer-Emmett-Teller (BET) isotherm and pseudo-second-order kinetic fitted well to the experimental data. The PS-b-PAA NPs on the PEC surfaces increase the AlClPc bioavailability and the PEC structure stabilizes the PS-b-PAA/AlClPc nanostructures. The materials were cytocompatible upon healthy VERO (kidney epithelial cells), and cytotoxic against colorectal cancerous cells (HT-29 cells). For the first time, we associate PS-b-PAA/AlClPc with a hydrophilic and cytocompatible polysaccharide matrix. We suggest the use of these materials in strategies to treat cancer by using photodynamic therapy.


Assuntos
Antineoplásicos/farmacologia , Materiais Biocompatíveis/farmacologia , Neoplasias Colorretais/tratamento farmacológico , Polieletrólitos/farmacologia , Polissacarídeos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Configuração de Carboidratos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Neoplasias Colorretais/patologia , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Tamanho da Partícula , Polieletrólitos/síntese química , Polieletrólitos/química , Polissacarídeos/síntese química , Polissacarídeos/química
13.
Carbohydr Polym ; 251: 117079, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33142622

RESUMO

In this study, a surface modification strategy using natural biopolymers on titanium is proposed to improve bone healing and promote rapid and successful osseointegration of orthopedic implants. Titania nanotubes were fabricated via an anodization process and the surfaces were further modified with polyelectrolyte multilayers (PEMs) based on Tanfloc (a cationic tannin derivative) and glycosaminoglycans (heparin and hyaluronic acid). Scanning electron microscopy (SEM), water contact angle measurements, and X-ray photoelectron spectroscopy were used to characterize the surfaces. Adipose-derived stem cells (ADSCs) were seeded on the surfaces, and the cell viability, adhesion, and proliferation were investigated. Osteogenesis was induced and osteogenic differentiation of human ADSCs on the surfaces was evaluated via mineralization and protein expression assays, immunofluorescent staining, and SEM. The Tanfloc/heparin PEMs on titania nanotubes improved the rate of osteogenic differentiation of ADSCs as well as the bone mineral deposition, and is therefore a promising approach for use in orthopedic implants.


Assuntos
Tecido Adiposo/citologia , Heparina/química , Nanotubos/química , Polieletrólitos/química , Células-Tronco/citologia , Taninos/química , Titânio/química , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/metabolismo , Anticoagulantes/química , Anticoagulantes/farmacologia , Adesão Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Heparina/farmacologia , Humanos , Ácido Hialurônico/química , Osteogênese , Polieletrólitos/farmacologia , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo , Propriedades de Superfície , Taninos/farmacologia
14.
Int J Mol Sci ; 21(22)2020 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-33212884

RESUMO

Pectin and chitosan films containing glycerol (Gly) at 5, 10, 15, 20, 30, and 40 wt % were prepared in an aqueous HCl solution (0.10 M) by the solvent evaporation method. The unwashed film (UF) containing 40 wt % Gly (UF40) had elongation at break (ε, %) of 19%. Washed films (WFs) had high tensile strength (σ > 46 MPa) and low elongation at break (ε, <5.0%), enabling their use in food packaging applications. The polymers' self-assembling occurred during the washing, increasing the stiffness. The XPS analysis suggests that some HCl is lost during the drying process, resulting in a low acid content on the UF surfaces. The UF40 (at 5.0 mg/mL) exhibits cytocompatibility toward mammalian cells and antimicrobial and anti-adhesive properties against Escherichia coli. The remaining HCl in the UF40 can be a disadvantage for food packaging applications; the UF40 (∅ = 8.5 mm; 55 µm thickness) releases H3O+/HCl, reducing the pH to approximately 3.0 when kept in 200 mL distilled water for approximately 30 min. Therefore, we propose the use of UF40 to coat commercial food packaging. The UF40 has low permeability to water vapor and oxygen and works as a barrier against ultraviolet light. The UF40 is also colorless and completely transparent. The UF40 maintained tomatoes' structural integrity for 18 days at room temperature with no oxidation or microorganism contamination. This paper presents a critical viewpoint concerning chitosan-based films with antimicrobial activities.


Assuntos
Antibacterianos/química , Quitosana/química , Materiais Revestidos Biocompatíveis/química , Escherichia coli/crescimento & desenvolvimento , Embalagem de Alimentos , Glicerol/química , Membranas Artificiais , Pectinas/química
15.
Int J Biol Macromol ; 165(Pt A): 582-590, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32991902

RESUMO

Biodegradable films have been a great alternative compared to non-renewable sources because of their cytocompatibility, biodegradability, and antimicrobial features. These properties may raise the foodstuff shelf life, reducing costs and economic losses. Indeed, biodegradable films can also reduce the environmental pollution promoted by non-biodegradable conventional packs. For the first time, biodegradable films were produced by casting commercials kappa-carrageenan (κ-car) and cassava starch at different κ-carrageenan/cassava starch weight ratios. Physical, thermal, and mechanical properties were evaluated. Apparent opacity and color analyses suggest that the films present high transparency. The sample 0κ-c supported a film with high water solubility (39.22%) and a low swelling degree (391.6%). The lowest water vapor permeability (WVP) was observed for 50κ-c (3.01×10-8g (Pams)-1). The oil permeability varied from 0.0033 to 0.0043mmm2 d-1. The 100κ-c and 75κ-c films (with high κ-carrageenan contents) had higher stiffness (19.23 and 25.88MPa, respectively) than the 25κ-c and 0κ-c films with elongation at break (ε) of 21.60 and 67.65%, respectively. The thermal stability increased as the starch concentration raised in the blend. We produced low-cost biodegradable films from commercial polysaccharides. These films can be used as food packs.


Assuntos
Carragenina/química , Embalagem de Alimentos , Manihot/química , Membranas Artificiais , Amido/química , Carragenina/economia , Manihot/economia
16.
Int J Biol Macromol ; 161: 977-998, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32553969

RESUMO

Conventional strategies (Turkevich's, and modified Turkevich's methods) often synthesize gold nanoparticles (AuNPs). These pathways produce AuNPs using toxic chemistries to reduce Au(III) and stabilize Au(0) atoms upon the AuNP surfaces. To overcome the disadvantages of conventional approaches, chitosan and chitosan-based materials associate with Au(III) to produce composites. Chitosan and derivatives reduce Au(III) and stabilize AuNPs, promoting biocompatibility to the composites, following approaches in-situ. In this review, we report methods to develop chitosan/AuNPs-based composites. The main criticism is about the mechanism of composite formation. Also, we highlight applications of chitosan/AuNPs-based devices in the biomedical arena. We report the synthesis of biosensors, drug delivery devices, scaffolds, antimicrobial coatings, and others. The major criticism is concerning the material design and the lack of data regarding the composite biocompatibility. We support a critical viewpoint.


Assuntos
Materiais Biocompatíveis/química , Quitosana/química , Ouro/química , Nanopartículas Metálicas/química , Animais , Pesquisa Biomédica/métodos , Humanos
17.
Mater Sci Eng C Mater Biol Appl ; 112: 110919, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32409070

RESUMO

To develop hemocompatible surfaces, a cationic tannin derivate (TN) was used to prepare polyelectrolyte multilayers (PEMs) with the glycosaminoglycans heparin (HEP) and chondroitin sulfate (CS). The surface chemistry of the PEMs was characterized using X-ray photoelectron spectroscopy and water contact angle measurements. PEMs assembled with chitosan (CHI) and HEP or CS were used as controls. We investigate the hemocompatibility of PEMs by analyzing the adsorption of key blood serum proteins, adhesion and activation of platelets, and blood clotting kinetics. TN- and CHI-based PEMs adsorb similar amounts of albumin, whereas fibrinogen adsorption was more pronounced on TN-based PEMs, due to strong association with catechol groups. However, TN-based PEMs significantly reduce both platelet adhesion and platelet activation, while CHI-based PEMs promote platelet adhesion and activation. The whole-blood clotting kinetics assay also shows lower blood coagulation on TN-based PEMs. TN is an amphoteric, cationic, condensed tannin derivative with resonance structures. It also contains catechol groups, which are similar to those in mussel adhesive protein. These chemical features enable strong association with fibrinogen, which promotes the platelet-repelling effect. This study provides a new perspective for understanding platelet adhesion and activation on biomaterial surfaces, toward the development of new blood-compatible surfaces using a tannin derivative-based polymer.


Assuntos
Materiais Biocompatíveis/química , Plaquetas/metabolismo , Proteínas Sanguíneas/química , Polieletrólitos/química , Taninos/química , Adsorção , Materiais Biocompatíveis/farmacologia , Coagulação Sanguínea/efeitos dos fármacos , Plaquetas/citologia , Plaquetas/efeitos dos fármacos , Quitosana/química , Sulfatos de Condroitina/química , Heparina/química , Humanos , Ativação Plaquetária/efeitos dos fármacos , Adesividade Plaquetária/efeitos dos fármacos , Polifenóis/química , Propriedades de Superfície , Molhabilidade
18.
Int J Biol Macromol ; 152: 77-89, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32092423

RESUMO

To obtain pectin-based films is challenging due to the aqueous instability of polyelectrolyte mixtures. We overcome this issue by blending chitosan to pectin of high O-methoxylation degree (56%), followed by solvent evaporation. A durable film containing 74 wt% pectin content was produced and used as an adsorbent material toward Cu(II) ions. Kinetic and adsorption equilibrium studies showed that the pseudo-second-order and Sips isotherm models adjusted well to the experimental data, respectively. Langmuir isotherm indicated a maximum adsorption capacity (qm) for Cu(II) removal of 29.20 mg g-1. Differential scanning calorimetry, contact angle measurements, and X-ray photoelectron spectroscopy confirm the adsorption. The chemisorption plays an essential role in the process; thereby, the film reusability is low. After adsorption, the cytocompatible film/Cu(II) pair prevents the proliferation of Escherichia coli.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Cobre/química , Cobre/isolamento & purificação , Pectinas/química , Pectinas/farmacologia , Água/química , Adsorção , Quitosana/química , Escherichia coli/efeitos dos fármacos , Cinética , Teste de Materiais , Metilação , Soluções
19.
J Biomed Mater Res A ; 108(4): 992-1005, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31909867

RESUMO

Biomaterial-associated thrombus formation and bacterial infection remain major challenges for blood-contacting devices. For decades, titanium-based implants have been largely used for different medical applications. However, titanium can neither suppress blood coagulation, nor prevent bacterial infections. To address these challenges, tanfloc/heparin polyelectrolyte multilayers on titania nanotubes array surfaces (NT) were developed. The surfaces were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and water contact angle measurements. To evaluate the hemocompatibility of the surfaces, fibrinogen adsorption, Factor XII activation, and platelet adhesion and activation were analyzed. The antibacterial activity was investigated against Gram-negative P. aeruginosa and Gram-positive S. aureus. Bacterial adhesion and morphology, as well as biofilm formation, were analyzed using fluorescence microscopy and SEM. The anti-thrombogenic properties of the surfaces were demonstrated by significant decreases in fibrinogen adsorption, Factor XII activation, and platelet adhesion and activation. Modifying NT with tanfloc/heparin also reduces the adhesion and proliferation of P. aeruginosa and S. aureus bacteria after 24 hr of incubation, with no biofilm formation. The modified NT surfaces with tanfloc/heparin polyelectrolyte multilayers are a promising biomaterial for use on implant surfaces because of their enhanced blood biocompatibility and antibacterial properties.


Assuntos
Antibacterianos/farmacologia , Materiais Biocompatíveis/farmacologia , Heparina/farmacologia , Nanotubos/química , Polieletrólitos/farmacologia , Titânio/farmacologia , Adsorção , Fator XII/metabolismo , Fibrinogênio/metabolismo , Humanos , Testes de Sensibilidade Microbiana , Nanotubos/ultraestrutura , Nitrogênio/química , Espectroscopia Fotoeletrônica , Adesividade Plaquetária/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/ultraestrutura , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/ultraestrutura , Propriedades de Superfície , Água/química
20.
Int J Biol Macromol ; 147: 138-149, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31923518

RESUMO

Studies report the production of gold nanoparticles (AuNPs) and polysaccharides-based composites. However, there are few reports about AuNPs synthesis in-situ followed by the formation of hydrogel composites. Here, we show AuNPs synthesis in-situ into the pectin solutions to yield cytocompatible pectin-capped AuNPs/chitosan hydrogel composites. Visible spectroscopy and dynamic light scattering measurements confirm the AuNPs synthesis. The hydrodynamic radius of the pectin-capped AuNPs ranges from approximately 510 to 721 nm, while the Zeta potential is around -43 mV. Scanning electron microscopy shows that the composites present compact structures. Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy characterize the composites as well. Hydrogels (with or without AuNPs) containing the highest pectin content (at 4.12 pectin/chitosan weight ratio) have low stability (disintegrates approximately 60% after 14 days in phosphate buffer). Composites obtained at 3.75 pectin/chitosan weight ratio disintegrate between 25 and 30% after 14 days in phosphate buffer (physiological condition = pH 7.4). The AuNPs reinforce the hydrogel structures, increasing the elastic modulus (from 3.5 to 7.6 Pa) and decreasing the water uptake from 4465 to 2976%. 3.75 PT/CS weight ratio and 3.0 × 10-4 M Au(III) content provide a durable, cytocompatible, and superabsorbent hydrogel composite. These properties can support materials for drug delivery purposes.


Assuntos
Absorção Fisico-Química , Quitosana/química , Ouro/química , Hidrogéis/química , Nanopartículas Metálicas/química , Pectinas/química , Tecido Adiposo/citologia , Animais , Morte Celular , Sobrevivência Celular , Espectroscopia Fotoeletrônica , Polieletrólitos/química , Espectrofotometria Ultravioleta , Células-Tronco/citologia
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