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1.
Acta Odontol Latinoam ; 37(2): 151-161, 2024 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-39484748

RESUMO

This study analyzed a recently developed bone substitute biomaterial made of chitosan-xanthanhydroxyapatite-graphene oxide (CXHAG). The CXHAG particles underwent in vitro structural and morphological characterization, and in vivo testing with or without osteogenic conditioned medium from mesenchymal stem cells. Aim: The aim of this study was to determine whether the CXHAG novel biomaterial, supplemented with conditioned medium from mesenchymal stem cells, could be useful for bone regeneration. Materials and Method: For the in vitro study, cells were incubated with 20mg of CXHAG granules for 24 hours and a MTT assay was performed to tests for cytotoxicity. For the in vivo study, critical size calvarial bone defects were created in twenty-five rats. One animal had the defect unfilled (Control Group-CG) and was euthanized after 42 days. Twelve rats received the CXHAG particles (Group 1-G1) and the other twelve received the CXHAG particles supplemented with the conditioned medium (Group 2-G2). All G1/G2 grafts were covered with a CXHAG membrane. G1/G2 animals were euthanized after 14 days (T1) or 42 days (T2). The specimens were processed and histologically evaluated. Results: SEM analysis of the CXHAG particles showed granules of 300-400µm, with a rough irregular surface. They were not cytotoxic to dental pulp stem cells in vitro. The CG specimen showed loose immature connective tissue and no bone formation at the center of the defect. G1 and G2 presented remnant biomaterial particles at both time points, but only G2 had bone formation at the enter of the defect. Conclusions: The conditioned medium had a positive effect on bone regeneration in rat calvarial critical size defects when associated with the novel bone substitute biomaterial.


Este estudo analisou um biomaterial substituto ósseo recentemente desenvolvido feito de óxido de quitosana-xantana-hidroxiapatita-grafeno (CXHAG). As partículas CXHAG observaram caracterização estrutural e morfológica in vitro. Foi testado in vivo, com ou sem meio condicionado osteogênico de células-tronco mesenquimais. Objetivo: O objetivo deste estudo foi determinar se o novo biomaterial CXHAG, suplementado com meio condicionado de células-tronco mesenquimais, poderia ser útil para a regeneração óssea. Materiais e Método: Para o estudo in vitro, as células foram incubadas com 20mg de grânulos de CXHAG por 24 horas e foi realizado ensaio de MTT para verificar a citotoxicidade. Para o estudo in vivo, foram criados defeitos ósseos de tamanho crítico na calvária em vinte e cinco ratos. Um animal teve o defeito não preenchido (Grupo Controle ­ GC) e foi eutanasiado após 42 dias. Doze ratos receberam as partículas CXHAG (Grupo 1 ­ G1) e os outros doze receberam as partículas CXHAG suplementadas com o meio condicionado (Grupo 2 ­ G2). Todos os enxertos G1/G2 foram cobertos com membrana CXHAG. Os animais do G1/G2 foram eutanasiados após 14 dias (T1) ou 42 dias (T2). Os espécimes foram processados e avaliados histologicamente. Resultados: A análise SEM das partículas CXHAG mostrou grânulos de 300-400µm, com superfície áspera e irregular. Eles não foram citotóxicos para células-tronco da polpa dentária in vitro. As amostras CG mostraram tecido conjuntivo imaturo frouxo e nenhuma formação óssea no centro do defeito. G1 e G2 apresentaram partículas remanescentes de biomateriais em ambos os momentos, mas apenas G2 apresentou formação óssea no centro do defeito. Conclusões: O meio condicionado teve repercussões positivas na regeneração óssea em defeitos críticos de calvária de ratos quando associado ao novo biomaterial substituto ósseo.


Assuntos
Regeneração Óssea , Substitutos Ósseos , Quitosana , Durapatita , Grafite , Células-Tronco Mesenquimais , Polissacarídeos Bacterianos , Ratos Wistar , Regeneração Óssea/efeitos dos fármacos , Animais , Quitosana/farmacologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Ratos , Meios de Cultivo Condicionados , Substitutos Ósseos/farmacologia , Polissacarídeos Bacterianos/farmacologia , Masculino , Materiais Biocompatíveis/farmacologia
2.
Curr Microbiol ; 81(12): 445, 2024 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-39499308

RESUMO

Colletotrichum fungus complex affects several crops and tropical products, which suffer significant losses due to anthracnose. The use of chitosan nanoparticles (CNPs), alone or in combination with bioactive compounds, has been recommend for agronomic applications. However, there is very little information on their phytotoxicity, and there is no information about the effect on microorganisms with low susceptibility to chitosan. This work aims to compare their antifungal effect against isolates of C. fructicola with low susceptibility to chitosan and to study the toxicological effects of CNPs on the germination of lettuce (Lactuca sativa) and radish (Raphanus sativus) seeds. Levels of phytotoxicity of high-to-very high and moderate-to-very high were observed for lettuce and radish seeds, respectively, with greater detrimental effects on the radicle elongation after exposure to CNPs concentrations of 4-5 g L-1. For the three C. fructicola isolates, the CNPs did not inhibit the fungal growth; however, the cell viability decreased as the CNPs concentration increased, and a complete inhibition of the viability was found for H4-1 and 003 isolates at a CNPs concentration of 5 g L-1. Morphometric alterations characterized by a reduction in the average length of the terminal hyphae, distortion, and a higher number of branches in the hyphae, were observed. To our knowledge, this is the first report where the effect of nanochitosan particles in Colletotrichum fructicola, with experimentally proven low sensitivity to chitosan, was studied.


Assuntos
Antifúngicos , Quitosana , Colletotrichum , Lactuca , Nanopartículas , Doenças das Plantas , Raphanus , Quitosana/farmacologia , Colletotrichum/efeitos dos fármacos , Colletotrichum/crescimento & desenvolvimento , Nanopartículas/química , Raphanus/microbiologia , Raphanus/efeitos dos fármacos , Antifúngicos/farmacologia , Antifúngicos/química , Lactuca/microbiologia , Lactuca/efeitos dos fármacos , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Germinação/efeitos dos fármacos , Sementes/microbiologia , Sementes/efeitos dos fármacos
3.
Braz J Med Biol Res ; 57: e14129, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39504069

RESUMO

Epithelial cancers, such as epidermoid cancer and some adenocarcinomas, affect surface areas that are generally more accessible to various treatments. However, this group of tumor cells has an aggressive behavior, leading to a high annual mortality rate. The development of a biomaterial that is non-invasive, can kill tumor cells, and prevent opportunistic infections is the basis for the treatment for this type of cancer. Therefore, the objective of this study was to develop a biomaterial from chitosan and A. oleracea extracts that exhibits cytotoxic action against the HEp-2 tumor cell line. Dried crude 90% ethanol extracts were obtained through ultrasound-assisted maceration, followed by liquid-liquid extraction to yield the butanol fraction. From these extracts, chitosan membranes were developed and evaluated for their antitumor activity against HEp-2 using viability tests with crystal violet and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, in addition to a wound healing test. The cytotoxic assays indicated a significant reduction in cell density and mitochondrial activity, especially at the concentration of 1000 µg/mL of crude extract. The butanol fraction had minimal effects on mitochondrial activity. The wound healing test demonstrated that the biomaterial and extract prevented closure of the wound created in the cell monolayer within 48 h of incubation and caused changes in cell morphology. In view of this, we concluded that a chitosan membrane associated with a 90% ethanol extract of Acmella oleracea exhibited cytotoxic activity is a potential alternative treatment for superficial cancers.


Assuntos
Quitosana , Extratos Vegetais , Extratos Vegetais/farmacologia , Humanos , Linhagem Celular Tumoral , Quitosana/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Antineoplásicos Fitogênicos/farmacologia , Asteraceae/química
4.
Int J Biol Macromol ; 281(Pt 1): 136180, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39357715

RESUMO

CD44 is a cell receptor glycoprotein overexpressed in circulating tumor cells (CTCs), with levels linked to an increase in metastatic capacity of several tumors. Hyaluronic acid (HA), the natural ligand of CD44, has primarily been investigated for tumor cell interaction in self-assembled polyelectrolyte multilayer films, with little attention given to the complementary polycation. In this study, we screened sixteen different polyelectrolyte multilayer assemblies of HA and chitosan (CHI) to identify key assembly parameters and surface properties that control and govern CTCs adhesion. Statistics analysis revealed a major role of CHI molecular weight in the adhesion, followed by its combinatorial response either with HA ionization degree or ionic strength. PM-IRRAS analysis demonstrated a correlation between the orientation of HA carboxyl groups on the film surface and CTCs adhesion, directly impacted by CHI molecular weight. Overall, although CTCs binding onto the surface of multilayer films is primarily driven by HA-CD44 interaction, both chitosan properties and film assembly conditions modulate this interaction. These findings illustrate an alternative to modifying the performance of biomaterials with minimal changes in the composition of multilayer films.


Assuntos
Adesão Celular , Quitosana , Ácido Hialurônico , Peso Molecular , Células Neoplásicas Circulantes , Ácido Hialurônico/química , Ácido Hialurônico/farmacologia , Quitosana/química , Quitosana/farmacologia , Humanos , Células Neoplásicas Circulantes/efeitos dos fármacos , Células Neoplásicas Circulantes/patologia , Adesão Celular/efeitos dos fármacos , Receptores de Hialuronatos/metabolismo , Propriedades de Superfície , Linhagem Celular Tumoral , Polieletrólitos/química
5.
Int J Mol Sci ; 25(20)2024 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-39456681

RESUMO

Fungi (Neolentinus lepideus, Nl, and Trametes versicolor, Tv) impart wood rot, leading to economic and environmental issues. To overcome this issue, toxic chemicals are commonly employed for wood preservation, impacting the environment and human health. Surface coatings based on antimicrobial chitosan (CS) of high molar mass (145 × 105 Da) were tested as wood preservation agents using an innovative strategy involving ultra-pressurizing CS solutions to deposit organic coatings on wood samples. Before coating deposition, the antifungal activity of CS in diluted acetic acid (AcOOH) solutions was evaluated against the rot fungi models Neolentinus lepideus (Nl) and Trametes versicolor (Tv). CS effectively inhibited fungal growth, particularly in solutions with concentrations equal to or higher than 0.125 mg/mL. Wood samples (Eucalyptus sp. and Pinus sp.) were then coated with CS under ultra-pressurization at 70 bar. The polymeric coating deposition on wood was confirmed through X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM) images, and water contact angle measurements. Infrared spectroscopy (FTIR) spectra of the uncoated and coated samples suggested that CS does not penetrate the bulk of the wood samples due to its high molar mass but penetrates in the surface pores, leading to its impregnation in wood samples. Coated and uncoated wood samples were exposed to fungi (Tv and Nl) for 12 weeks. In vivo testing revealed that Tv and Nl fungi did not grow on wood samples coated with CS, whereas the fungi proliferated on uncoated samples. CS of high molar mass has film-forming properties, leading to a thin hydrophobic film on the wood surface (water contact angle of 118°). This effect is mainly attributed to the high molar mass of CS and the hydrogen bonding interactions established between CS chains and cellulose. This hydrophobic film prevents water interaction, resulting in a stable coating with insignificant leaching of CS after the stability test. The CS coating can offer a sustainable strategy to prevent wood degradation, overcoming the disadvantages of toxic chemicals often used as wood preservative agents.


Assuntos
Quitosana , Interações Hidrofóbicas e Hidrofílicas , Madeira , Quitosana/química , Quitosana/farmacologia , Madeira/química , Madeira/microbiologia , Antifúngicos/farmacologia , Antifúngicos/química , Propriedades de Superfície , Polyporaceae
6.
J Biomed Mater Res B Appl Biomater ; 112(10): e35485, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39324392

RESUMO

The development of new wound dressings made from biomaterials, which offer a better cost-benefit ratio and accelerate the healing process, is increasing nowadays. Various biopolymers can be electrospun to form functional membranes for wound healing. Therefore, in this study, chitosan and nanochitosan membranes with or without hyaluronic acid were prepared using the electrospinning technique, characterized and evaluated in the healing of skin wounds in rats. Chitosan and nanochitosan solutions, with or without hyaluronic acid, were prepared at concentrations of 1%-4% using PEO (polyethylene oxide) and subjected to the electrospinning process to obtain membranes characterized by scanning electron microscopy (SEM), mechanical tests, and antimicrobial activity. The healing effect of the membranes was evaluated by monitoring the area of the lesions, contraction of the wounds, histologic analysis, and induction of pro-inflammatory cytokine (IL-1 α and TNF-α) production in rats. The nanochitosan and nanochitosan membranes with hyaluronic acid achieved greater fiber diameter and uniformity, resistance, elasticity, and thermal stability, in addition to good adhesion to the wound bed and permeation capacity. Despite not presenting antimicrobial activity in vitro, they contributed to the production of pro-inflammatory interleukins in the animals tested, provided physical protection, reduced the wound area more markedly until the seventh day of the evaluation, with an acceleration of the healing process and especially when functionalized with hyaluronic acid. These results indicate that the membranes may be promising for accelerating the healing process of chronic wounds in humans.


Assuntos
Quitosana , Ácido Hialurônico , Membranas Artificiais , Pele , Cicatrização , Quitosana/química , Quitosana/farmacologia , Animais , Ácido Hialurônico/química , Ácido Hialurônico/farmacologia , Cicatrização/efeitos dos fármacos , Ratos , Pele/lesões , Pele/metabolismo , Masculino , Ratos Wistar , Bandagens
7.
Int J Biol Macromol ; 280(Pt 4): 135995, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39326592

RESUMO

In this work, chitosan/collagen-based membranes loaded with 2,3-dihydrobenzofuran (2,3-DHB) were developed through a simple solvent-casting procedure for use in the treatment of cutaneous Leishmaniasis. The obtained membranes were characterized by elemental analysis, FTIR, TG, DSC, and XRD. Porosity, swelling, mechanical properties, hydrophilicity, and antioxidant activity were analyzed. In addition, assessment to the biocompatibility, through fibroblasts/keratinocytes and in vitro wound healing essays were performed. The obtained results show that the new 2,3-DHB loaded chitosan/collagen membrane presented high porosity and swelling capacity as well as maximum strength, hydrophilicity, and antioxidant activity higher in relation to the control. The tests of antileishmanial activity and the AFM images demonstrate great efficacy of inhibition growth of the parasite, superior to those from the standard therapeutic agent that is currently used: Amphotericin B. The new membranes are biocompatible and stimulated the proliferation of keratinocytes. SEM images clearly demonstrate that fibroblasts were able to adhere, maintained their characteristic morphology. The healing test evidenced that the membranes have adequate environment for promoting cell proliferation and growth. As the conventional treatments often use drugs with high toxicity, the as-developed new membranes proved to be excellent candidate to treat cutaneous Leishmaniasis and can be clearly indicated for further advanced studies in vivo.


Assuntos
Benzofuranos , Quitosana , Colágeno , Leishmaniose Cutânea , Quitosana/química , Quitosana/farmacologia , Leishmaniose Cutânea/tratamento farmacológico , Leishmaniose Cutânea/parasitologia , Benzofuranos/farmacologia , Benzofuranos/química , Colágeno/química , Humanos , Membranas Artificiais , Antiprotozoários/farmacologia , Antiprotozoários/química , Fibroblastos/efeitos dos fármacos , Porosidade , Animais , Cicatrização/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Antioxidantes/farmacologia , Antioxidantes/química , Queratinócitos/efeitos dos fármacos
8.
Int J Mol Sci ; 25(18)2024 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-39337380

RESUMO

The rapid resistance developed by pathogenic microorganisms against the current antimicrobial pool represents a serious global public health problem, leading to the search for new antibiotic agents. The scorpion Tityus stigmurus, an abundant species in Northeastern Brazil, presents a rich arsenal of bioactive molecules in its venom, with high potential for biotechnological applications. However, venom cytotoxicity constitutes a barrier to the therapeutic application of its different components. The objective of this study was to produce T. stigmurus-venom-loaded cross-linked chitosan nanoparticles (Tsv/CN) at concentrations of 0.5% and 1.0% to improve their biological antimicrobial activity. Polymeric nanoparticles were formed with a homogeneous particle size and spherical shape. Experimental formulation parameters were verified in relation to mean size (<180 nm), zeta potential, polydispersity index and encapsulation efficiency (>78%). Tsv/CN 1.0% demonstrated an ability to increase the antimicrobial venom effect against Staphylococcus aureus bacteria, exhibiting an MIC value of 44.6 µg/mL. It also inhibited different yeast species of the Candida genus, and Tsv/CN 0.5% and 1.0% led to a greater inhibitory effect of C. tropicalis and C. parapsilosis strains, presenting MIC values between 22.2 and 5.5 µg/mL, respectively. These data demonstrate the biotechnological potential of these nanosystems to obtain a new therapeutic agent with potential antimicrobial activity.


Assuntos
Quitosana , Testes de Sensibilidade Microbiana , Nanopartículas , Venenos de Escorpião , Escorpiões , Quitosana/química , Quitosana/farmacologia , Nanopartículas/química , Animais , Venenos de Escorpião/química , Venenos de Escorpião/farmacologia , Escorpiões/química , Staphylococcus aureus/efeitos dos fármacos , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Candida/efeitos dos fármacos , Tamanho da Partícula , Antibacterianos/farmacologia , Antibacterianos/química , Animais Peçonhentos
9.
Carbohydr Polym ; 344: 122496, 2024 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-39218539

RESUMO

Chitosan is a promising natural polymer for coatings, it combines intrinsic antibacterial and pro-osteoblastic properties, but the literature still has a gap from the development to behavior of these coatings, so this systematic review aimed to answer, "What is the relationship between the physical and chemical properties of polymeric chitosan coatings on titanium implants on antibacterial activity and osteoblast viability?". PRISMA guidelines was followed, the search was applied into 4 databases and grey literature, without the restriction of time and language. The selection process occurred in 2 blinded steps by the authors. The criteria of eligibility were in vitro studies that evaluated the physical, chemical, microbiological, and biological properties of chitosan coatings on titanium surfaces. The risk of bias was analyzed by the specific tool. Of 734 potential articles 10 were included; all had low risk of bias. The coating was assessed according to the technique of fabrication, FT-IR, thickness, adhesion, roughness, wettability, antibacterial activity, and osteoblast viability. The analyzed coatings showed efficacy on antibacterial activity and cytocompatibility dependent on the class of material incorporated. Thus, this review motivates the development of time-dependent studies to optimize manufacturing and allow for an increase in patents and availability on the market.


Assuntos
Antibacterianos , Quitosana , Materiais Revestidos Biocompatíveis , Osteoblastos , Titânio , Quitosana/química , Quitosana/farmacologia , Titânio/química , Titânio/farmacologia , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Humanos , Antibacterianos/farmacologia , Antibacterianos/química , Osteoblastos/efeitos dos fármacos , Osteoblastos/citologia , Propriedades de Superfície , Próteses e Implantes , Animais , Sobrevivência Celular/efeitos dos fármacos
10.
Int J Biol Macromol ; 279(Pt 3): 135327, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39236955

RESUMO

The immunoregulatory cation channel TMEM176B plays a dual role in tumor immunity. On the one hand, TMEM176B promotes antigen cross-presentation to CD8+ T cells by regulating phagosomal pH in dendritic cells (DCs). On the other hand, it inhibits NLRP3 inflammasome activation through ionic mechanisms in DCs, monocytes and macrophages. We speculated that formulating BayK8644 in PEGylated chitosan nanoparticles (NP-PEG-BayK8644) should slowly release the compound and by that mean avoid cross-presentation inhibition (which happens with a fast 30 min kinetics) while still triggering inflammasome activation. Chitosan nanocarriers were successfully obtained, exhibiting a particle size within the range of 200 nm; they had a high positive surface charge and a 99 % encapsulation efficiency. In in vitro studies, NP-PEG-BayK8644 did not inhibit antigen cross-presentation by DCs, unlike the free compound. The NP-PEG-BayK8644 activated the inflammasome in a Tmem176b-dependent manner in DCs. We administered either empty (eNP-PEG) or NP-PEG-BayK8644 to mice with established tumors. NP-PEG-BayK8644 significantly controlled tumor growth and improved mice survival compared to both eNP-PEG and free BayK8644 in melanoma and lymphoma models. This effect was associated with enhanced inflammasome activation by DCs in the tumor-draining lymph node and infiltration of the tumor by CD8+ T cells. Thus, encapsulation of BayK8644 in chitosan NPs improves the anti-tumoral properties of the compound by avoiding inhibition of antigen cross-presentation.


Assuntos
Imunidade Adaptativa , Quitosana , Células Dendríticas , Imunidade Inata , Nanopartículas , Quitosana/química , Quitosana/farmacologia , Animais , Nanopartículas/química , Camundongos , Imunidade Adaptativa/efeitos dos fármacos , Células Dendríticas/imunologia , Células Dendríticas/efeitos dos fármacos , Imunidade Inata/efeitos dos fármacos , Proteínas de Membrana/imunologia , Inflamassomos/metabolismo , Linhagem Celular Tumoral , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Melanoma Experimental/imunologia , Melanoma Experimental/patologia , Melanoma Experimental/tratamento farmacológico , Polietilenoglicóis/química , Polietilenoglicóis/farmacologia
11.
Mar Environ Res ; 202: 106747, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39293272

RESUMO

Microplastics (MP) are omnipresent in aquaculture and can induce several toxic effects, mainly oxidative stress. Therefore, alternatives to minimize these effects are welcome. In this study, chitosan (1 and 3 g/kg) was supplemented through the feed of farmed shrimp P. vannamei for 30 days. After this period, the shrimp were exposed to MP (0.5 mg/L) for 7 days. The results showed the presence of MP in hepatopancreas, gills and muscle. Hepatopancreas morphological alterations, as well as lipid peroxidation, a decrease in GSH level, and an increase in SOD activity indicated an oxidative stress that was reversed by chitosan. The muscle was also affected by MP, showing decreased CAT activity and increased SOD activity, though no lipid peroxidation was observed. In muscle, chitosan reversed the SOD increase to basal activity. The results obtained showed that chitosan was more effective against oxidative stress than in preventing accumulation and histological damage.


Assuntos
Antioxidantes , Aquicultura , Quitosana , Microplásticos , Estresse Oxidativo , Penaeidae , Poluentes Químicos da Água , Animais , Quitosana/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Penaeidae/efeitos dos fármacos , Penaeidae/fisiologia , Antioxidantes/metabolismo , Poluentes Químicos da Água/toxicidade , Microplásticos/toxicidade , Ração Animal/análise , Peroxidação de Lipídeos/efeitos dos fármacos , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Superóxido Dismutase/metabolismo , Hepatopâncreas/efeitos dos fármacos
12.
Int J Biol Macromol ; 279(Pt 4): 135423, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39251000

RESUMO

Herein, four different grafted chitosans were synthesized by covalent attachment of glycine, L-arginine, L-glutamic acid, or L-cysteine to the chitosan chains. All products were subsequently permethylated to obtain their corresponding quaternary ammonium salts to enhance the inherent antimicrobial properties of native chitosan. In all cases, transparent hydrogels with the following remarkable characteristics were obtained: i) high-water absorption capacity (32-44 g H2O per g of polymer), ii) viscoelastic behavior at low deformations, iii) flexibility when subjected to deformations and iv) stability over long time scales. All the permethylated derivatives successfully inhibited 100 % of the growth of S. aureus. They also exhibited higher antimicrobial activity against E. coli than native chitosan. The structure of the chemically crosslinked products was more stable under external perturbations than that of the physically crosslinked ones. Between the chemically crosslinked products, the permethylated glutamic acid-grafted chitosan exhibited a noteworthy higher water absorption capacity with respect to that modified with cysteine, which makes it the most promising material for various industrial applications, including biomedical and food industries. Regarding biomedical applications, this derivative met the required physicochemical criteria for wound dressings, which encourages the pursuit of biological studies necessary to ensure the safety of its use for this application.


Assuntos
Bandagens , Quitosana , Hidrogéis , Quitosana/química , Quitosana/farmacologia , Hidrogéis/química , Hidrogéis/farmacologia , Hidrogéis/síntese química , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Antibacterianos/farmacologia , Antibacterianos/química , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Água/química , Cicatrização/efeitos dos fármacos , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia
13.
Carbohydr Polym ; 346: 122640, 2024 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-39245504

RESUMO

Chitosan chemical functionalization is a powerful tool to provide novel materials for additive manufacturing strategies. The main aim of this study was the employment of computer-aided wet spinning (CAWS) for the first time to design and fabricate carboxymethyl chitosan (CMCS) scaffolds. For this purpose, the synthesis of a chitosan derivative with a high degree of O-substitution (1.07) and water soluble in a large pH range allowed the fabrication of scaffolds with a 3D interconnected porous structure. In particular, the developed scaffolds were composed of CMCS fibers with a small diameter (< 60 µm) and a hollow structure due to a fast non solvent-induced coagulation. Zn2+ ionotropic crosslinking endowed the CMCS scaffolds with stability in aqueous solutions, pH-sensitive water uptake capability, and antimicrobial activity against Escherichia coli and Staphylococcus aureus. In addition, post-printing functionalization through collagen grafting resulted in a decreased stiffness (1.6 ± 0.3 kPa) and a higher elongation at break (101 ± 9 %) of CMCS scaffolds, as well as in their improved ability to support in vitro fibroblast viability and wound healing process. The obtained results encourage therefore further investigation of the developed scaffolds as antimicrobial wound dressing hydrogels for skin regeneration.


Assuntos
Antibacterianos , Bandagens , Quitosana , Escherichia coli , Staphylococcus aureus , Alicerces Teciduais , Cicatrização , Quitosana/química , Quitosana/análogos & derivados , Quitosana/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Alicerces Teciduais/química , Antibacterianos/farmacologia , Antibacterianos/química , Animais , Camundongos , Fibroblastos/efeitos dos fármacos , Porosidade , Sobrevivência Celular/efeitos dos fármacos , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/síntese química , Reagentes de Ligações Cruzadas/química , Humanos
14.
Int J Biol Macromol ; 278(Pt 3): 134861, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39163960

RESUMO

This work reports the virucidal properties of nonwoven fibers developed via electrospinning with polycaprolactone (PCL) and chitosan quaternized with phosphonium salt (NPCS), emphasizing the influence of NPCS concentration on the structure of fibers and their performance against the MHV-3 coronavirus. The addition of NPCS enhances solutions conductivity and viscosity, leading to fibers containing a finer porous structure with a more hydrophilic and smoother surface, thereby making them a potent barrier against respiratory particles, which is a key factor for protective face masks. In terms of degradation, NPCS paced-up the process, suggesting potential environmental benefits. PCL/NPCS (90/10) fibers exhibit a 99 % coronavirus inhibition within a five-minute exposure without cellular toxicity, while also meeting breathability standards for medical masks. These findings suggest the use of NPCS as a promising strategy to design materials with remarkable virucidal performance and physical characteristics that reinforce their use in the field of biomaterials engineering.


Assuntos
Antivirais , Quitosana , Poliésteres , Quitosana/química , Quitosana/farmacologia , Poliésteres/química , Antivirais/química , Antivirais/farmacologia , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Humanos
15.
J Dent ; 149: 105316, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39159744

RESUMO

OBJECTIVES: This study assessed the effect of NaF/Chit suspensions on enamel and on S. mutans biofilm, simulating application of a mouthrinse. METHODS: The NaF/Chit particle suspensions were prepared at molar ratio [NaF]/Chitmon]≈0.68 at nominal concentrations of 0.2 % and 0.05 % NaF and characterized by Fourier transform infrared spectroscopy (FTIR), dynamic light scattering and zeta potential. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were measured. The S. mutans biofilm was formed for 7 days on eighty human enamel blocks that were divided into eight groups (n = 10/group): i) 0.05 % NaF solution; ii) 0.31 % Chit solution; iii) NaF/Chit(R=0.68) suspension at 0.05 % NaF; iv) 1.0 % HAc solution (Control); v) 0.2 % NaF solution; vi) 1.25 % Chit solution; vii) NaF/Chit(R=0.68) suspension at 0.2 % NaF; viii) 0.12 % chlorhexidine digluconate. The substances were applied daily for 90 s. S. mutans cell counts (CFU/mL) were performed, and the Knoop microhardness (KHN) of enamel samples were measured before and after biofilm formation. The KHN and CFU/mL data were analyzed by repeated measure ANOVA and Tukey's test (α = 0.05). RESULTS: Interactions between NaF and Chit were evidenced in solid state by FTIR spectra. The NaF/Chit complexes showed spontaneous microparticle formation and colloidal stability. The MIC and MBC ranged from 0.65 to 1.31 mg/mL. The NaF/Chit(R=0.68) suspension at 0.2 %NaF Group showed lower CFU/mL values than other groups. The NaF/Chit(R=0.68) suspensions Groups had the highest KHN values after biofilm formation. CONCLUSIONS: The NaF/Chit(R=0.68) complexes exhibited an antibacterial effect against S. mutans biofilm and reduced the enamel hardness loss. CLINICAL SIGNIFICANCE: The NaF/Chit(R=0.68) suspensions showed potential to be used as a mouthrinse for caries prevention.


Assuntos
Antibacterianos , Biofilmes , Quitosana , Esmalte Dentário , Testes de Sensibilidade Microbiana , Fluoreto de Sódio , Streptococcus mutans , Biofilmes/efeitos dos fármacos , Streptococcus mutans/efeitos dos fármacos , Esmalte Dentário/efeitos dos fármacos , Esmalte Dentário/microbiologia , Humanos , Antibacterianos/farmacologia , Fluoreto de Sódio/farmacologia , Quitosana/farmacologia , Quitosana/química , Espectroscopia de Infravermelho com Transformada de Fourier , Antissépticos Bucais/farmacologia , Antissépticos Bucais/química , Coloides , Cariostáticos/farmacologia , Cariostáticos/química
16.
Pest Manag Sci ; 80(12): 6096-6106, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39092877

RESUMO

BACKGROUND: Growing concerns about sustainability have driven the search for eco-friendly pest management solutions. Combining natural and synthetic compounds within controlled release systems is a promising strategy. This study investigated the co-encapsulation of the natural compound citral (Cit) and the synthetic antifungal cyproconazole (CPZ) using two water-based nanocarriers: solid lipid nanoparticles (SLNs) and chitosan nanoparticles (CSNPs). RESULTS: Both CSNPs and SLNs loaded with Cit + CPZ displayed superior antifungal activity against Botrytis cinerea compared to free compounds. Notably, CSNPs with a 2:1 Cit:CPZ ratio exhibited the highest efficacy, achieving a minimum inhibitory concentration (MIC100) of < 1.56 µg mL-1, lower than the 12.5 µg mL-1 of non-encapsulated compounds. This formulation significantly reduced the required synthetic CPZ while maintaining efficacy, highlighting its potential for environmentally friendly pest control. CONCLUSION: The successful co-encapsulation of Cit + CPZ within CSNPs, particularly at a 2:1 ratio, demonstrates a promising approach for developing effective and sustainable antifungal formulations against B. cinerea. © 2024 Society of Chemical Industry.


Assuntos
Monoterpenos Acíclicos , Botrytis , Fungicidas Industriais , Nanopartículas , Botrytis/efeitos dos fármacos , Monoterpenos Acíclicos/farmacologia , Nanopartículas/química , Fungicidas Industriais/farmacologia , Fungicidas Industriais/química , Triazóis/farmacologia , Triazóis/química , Testes de Sensibilidade Microbiana , Quitosana/farmacologia , Quitosana/química , Portadores de Fármacos/química , Antifúngicos/farmacologia , Antifúngicos/química , Lipídeos/química , Composição de Medicamentos , Doenças das Plantas/prevenção & controle , Doenças das Plantas/microbiologia
17.
ACS Appl Bio Mater ; 7(7): 4642-4653, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38967050

RESUMO

Titanium-based implants have long been studied and used for applications in bone tissue engineering, thanks to their outstanding mechanical properties and appropriate biocompatibility. However, many implants struggle with osseointegration and attachment and can be vulnerable to the development of infections. In this work, we have developed a composite coating via electrophoretic deposition, which is both bioactive and antibacterial. Mesoporous bioactive glass particles with gentamicin were electrophoretically deposited onto a titanium substrate. In order to validate the hypothesis that the quantity of particles in the coatings is sufficiently high and uniform in each deposition process, an easy-to-use image processing algorithm was designed to minimize human dependence and ensure reproducible results. The addition of loaded mesoporous particles did not affect the good adhesion of the coating to the substrate although roughness was clearly enhanced. After 7 days of immersion, the composite coatings were almost dissolved and released, but phosphate-related compounds started to nucleate at the surface. With a simple and low-cost technique like electrophoretic deposition, and optimized stir and suspension times, we were able to synthesize a hemocompatible coating that significantly improves the antibacterial activity when compared to the bare substrate for both Gram-positive and Gram-negative bacteria.


Assuntos
Antibacterianos , Quitosana , Eletroforese , Gentamicinas , Vidro , Teste de Materiais , Nanopartículas , Tamanho da Partícula , Propriedades de Superfície , Titânio , Gentamicinas/farmacologia , Gentamicinas/química , Titânio/química , Titânio/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Vidro/química , Nanopartículas/química , Quitosana/química , Quitosana/farmacologia , Porosidade , Testes de Sensibilidade Microbiana , Humanos , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Próteses e Implantes , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia
18.
Nitric Oxide ; 150: 37-46, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39038732

RESUMO

The combination of nitric oxide (NO) donors with nanomaterials has emerged as a promising approach to reduce postharvest losses. The encapsulation of NO donors provides protection from rapid degradation and controlled release, enhancing the NO effectiveness in postharvest treatments. Moreover, the application method can also influence postharvest responses. In this study, two application methods were evaluated, spraying and immersion, using S-nitrosoglutathione (GSNO, a NO donor) in free and encapsulated forms on papaya fruit. Our hypothesis was that GSNO encapsulated in chitosan nanoparticles would outperform the free form in delaying fruit senescence. In addition, this study marks the pioneering characterization of chitosan nanoparticles containing GSNO within the framework of a postharvest investigation. Overall, our findings indicate that applying encapsulated GSNO (GSNO-NP-S) through spraying preserves the quality of papaya fruit during storage. This method not only minimizes weight loss, ethylene production, and softening, but also stimulates antioxidant responses, thereby mitigating oxidative damage. Consequently, it stands out as the promising technique for delaying papaya fruit senescence. This innovative approach holds the potential to enhance postharvest practices and advance sustainable agriculture.


Assuntos
Carica , Quitosana , Frutas , Doadores de Óxido Nítrico , S-Nitrosoglutationa , Carica/química , Doadores de Óxido Nítrico/farmacologia , Doadores de Óxido Nítrico/química , Frutas/química , S-Nitrosoglutationa/farmacologia , S-Nitrosoglutationa/química , Quitosana/química , Quitosana/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Nanopartículas/química , Conservação de Alimentos/métodos
19.
Lasers Med Sci ; 39(1): 184, 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39020076

RESUMO

PURPOSE: This study aimed to investigate the efficiency of antimicrobial photodynamic therapy (aPDT) on Streptococcus mutans biofilm in the oral cavity using the photosensitizer chloroaluminum phthalocyanine encapsulated in chitosan nanoparticles (ClAlPc/Ch) at three preirradiation times. METHODS: Biofilms of Streptococcus mutans strains (ATCC 25,175) were cultivated on bovine tooth blocks and exposed to a 10% sucrose solution three times a day for 1 min over three consecutive days. The samples were randomly distributed into five treatment groups (n = 5): (I) aPDT with ClAlPc/Ch with a preirradiation time of 5 min (F5), (II) aPDT with ClAlPc/Ch with a preirradiation time of 15 min (F15), (III) aPDT with ClAlPc/Ch with a preirradiation time of 30 min (F30), (IV) 0.12% chlorhexidine digluconate (CHX), and (V) 0.9% saline solution (NaCl). After treatment, the S. mutans biofilms formed on each specimen were collected to determine the number of viable bacteria (colony-forming units (CFU)/mL). Data were analyzed for normality using the Shapiro-Wilk test and the analysis of variance (ANOVA) and Tukey HSD tests to analyze the number of viable bacteria (α = 0.05). RESULTS: The one-way ANOVA showed a difference between the groups (p = 0.0003), and the Tukey HSD posttest showed that CHX had the highest microbial reduction of S. mutans, not statistically different from the F5 and F15 groups, whereas the NaCl group had the lowest microbial reduction statistically similar to the F30 group. CONCLUSION: The results demonstrate that aPDT mediated by ClAlPc/Ch when used at preirradiation times of 5-15 min can be an effective approach in controlling cariogenic biofilm of S. mutans, being an alternative to 0.12% CHX.


Assuntos
Biofilmes , Quitosana , Nanopartículas , Fotoquimioterapia , Fármacos Fotossensibilizantes , Streptococcus mutans , Streptococcus mutans/efeitos dos fármacos , Streptococcus mutans/efeitos da radiação , Streptococcus mutans/fisiologia , Fotoquimioterapia/métodos , Quitosana/farmacologia , Quitosana/química , Nanopartículas/química , Biofilmes/efeitos dos fármacos , Biofilmes/efeitos da radiação , Animais , Bovinos , Fármacos Fotossensibilizantes/farmacologia , Técnicas In Vitro , Indóis/farmacologia , Boca/microbiologia , Clorexidina/farmacologia , Clorexidina/análogos & derivados , Viabilidade Microbiana/efeitos dos fármacos , Viabilidade Microbiana/efeitos da radiação , Compostos Organometálicos
20.
Carbohydr Res ; 543: 109220, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39038396

RESUMO

Chitin is a polymer of N-acetylglucosamine and an essential component of the fungal cell wall. Chitosan is the deacetylated form of chitin and is also important for maintaining the integrity of this structure. Both polysaccharides are widely distributed in nature and have been shown to have a variety of applications in biomedicine, including their potential in immune sensing and as potential antifungal agents. In addition, chitin has been reported to play an important role in the pathogen-host interaction, involving innate and adaptive immune responses. This paper will explore the role of chitin and chitosan when incorporated into nanobiocomposites to improve their efficacy in detecting fungi of medical interest and inhibiting their growth. Potential applications in diagnostic and therapeutic medicine will be discussed, highlighting their promise in the development of more sensitive and effective tools for the early diagnosis of fungal infections. This review aims to highlight the importance of the convergence of nanotechnology and biology in addressing public health challenges.


Assuntos
Antifúngicos , Quitina , Quitosana , Fungos , Quitina/química , Quitina/farmacologia , Quitosana/química , Quitosana/farmacologia , Antifúngicos/farmacologia , Antifúngicos/química , Fungos/efeitos dos fármacos , Fungos/química , Humanos , Nanocompostos/química , Micoses/imunologia , Micoses/tratamento farmacológico , Micoses/diagnóstico
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