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1.
Food Res Int ; 200: 115431, 2025 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-39779077

RESUMO

Layer-by-Layer (LbL) self-assembly encapsulation is a promising technology for the protection and delivery of lactic acid bacteria. However, laboratory-scale encapsulation is often time-consuming, involves intensive protocols tailored for small-scale operations, requires substantial amounts of energy and water, and results in a low yield of encapsulated biomass. Scaling-up this process to a bench-bioreactor scale is not simply a matter of increasing culture volume as different key parameters (not particularly relevant at lab scale) become critical, including biomass production, the number of polymer layers, and the biomass-to-polymer mass ratio. To our knowledge, this work is the first to address the optimization of each stage of the encapsulation process for Lactiplantibacillus plantarum WCFS1. These stages include biomass production, handling of encapsulation polymers [chitosan (Chi) and alginate (Alg)], critical LbL parameters (e.g., biomass concentration, washing steps). The encapsulation efficiency was assessed by plate-counting microorganisms before and after coating with the polymers layers, followed by spray- and freeze-drying dehydration using fructo-oligosaccharides (FOS) and maltodextrin as carriers. Once dehydrated, microorganisms were either exposed to gastrointestinal conditions or stored for 30 days at 25 and 30 °C. Supplementing culture media with glucose, controlling pH, and harvesting at the early stationary phase during biomass production increased the bacterial recovery after LbL encapsulation (decrease < 1 log unit) compared to bacteria grown under non-controlled conditions (decrease of 4 log units). Coating bacteria (B) with up to two polymer layers (B|Chi or B|Chi|Alg) did not significantly affect bacterial culturability, unlike adding further layers. Zeta-potential measurements enabled the determination of the optimal biomass-to-polymer mass ratio. Using up to a 10:1 bacterial-to-polymer ratio did not change the z-potential for B|Chi or B|Chi|Alg samples. After drying, a synergistic effect between the LbL coating and carrier compounds (FOS and maltodextrin) was observed in terms of culturability. LbL encapsulation mitigated thermal and acidic stresses during spray-drying and gastrointestinal exposure. These findings support scaling-up LbL encapsulation for delivering sensitive lactic acid bacteria strains to the gut.


Assuntos
Biomassa , Alginatos/química , Quitosana/química , Polissacarídeos/química , Liofilização , Lactobacillus plantarum/crescimento & desenvolvimento , Lactobacillus plantarum/metabolismo , Probióticos , Oligossacarídeos/química
2.
Toxins (Basel) ; 17(1)2025 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-39852979

RESUMO

Significant agro-industrial waste is produced during the winemaking process, including grape stalks, which are a rich source of the valuable biopolymer holocellulose that can be utilized for biotechnological processes. The purpose of this study was to delignify grape stalks in order to extract holocellulose. Then Lactobacillus plantarum (LP) was immobilized in the interstitial spaces of holocellulose and then coated with natural polymers (chitosan, Ch; and alginate, Al) to create the Holo-LP/Ch/Al complex. A physicochemical analysis of the system revealed strong bacterial immobilization and stability. The efficiency of the complex in adsorbing ochratoxin A (OTA) from wine model solutions was assessed using a Box-Behnken design under various pH, time, and concentration conditions. The results showed that at pH 3.0, 75.39 min, and a complex concentration of 43.82 mg mL-1, the best OTA removal (53.68%) took place. Because of its physicochemical interactions, the complex showed improved OTA adsorption in acidic environments. This study demonstrates the potential of biopolymeric systems based on holocellulose for reducing mycotoxin contamination in beverages and stabilizing bacterial cells. These results offer a viable way to increase food safety and value winemaking by-products.


Assuntos
Ocratoxinas , Vinho , Ocratoxinas/química , Vinho/análise , Adsorção , Lactobacillus plantarum/metabolismo , Células Imobilizadas/metabolismo , Celulose/química , Vitis/química , Vitis/microbiologia , Concentração de Íons de Hidrogênio , Biopolímeros/química , Alginatos/química , Quitosana/química , Contaminação de Alimentos/análise , Contaminação de Alimentos/prevenção & controle
3.
J Biomed Mater Res B Appl Biomater ; 113(2): e35536, 2025 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-39888107

RESUMO

In the present study, chitosan microspheres (MSCH) loaded with different concentrations of simvastatin (2%, 5%, and 10%) were synthesized as a biomaterial for dentin tissue engineering. The microspheres were prepared by emulsion crosslinking method, and simvastatin was incorporated during the process. The microspheres were then physicochemically and morphologically characterized. Scanning electron microscopy and infrared spectroscopy confirmed the spherical morphology of synthesized microspheres and the chemical incorporation of simvastatin into MSCH, respectively. UV-visible absorption confirmed the controlled and continuous release pattern of the drug. To mimic the clinical application in vitro, the microspheres were applied onto three-dimensional (3D) cultures of human dental pulp cells (HDPCs). Cell viability, proliferation, and in situ-mineralized matrix deposition were evaluated. The results indicated no cytotoxic effects for all 3D cultures for all tested biomaterials, with cells being able to proliferate significantly over time. HDPCs showed a significant increase in the deposition of mineralization nodules when 3D cultures were in direct contact with chitosan microspheres in comparison to control; nevertheless, the highest expression was observed for MSCH encapsulated with 5% and 10% simvastatin, which was significantly higher than plain MSCH. Therefore, chitosan microsphere systems loaded with 5%-10% simvastatin provided the development of a controlled release system in bioactive dosages for dentin tissue engineering.


Assuntos
Quitosana , Polpa Dentária , Dentina , Microesferas , Sinvastatina , Engenharia Tecidual , Sinvastatina/química , Sinvastatina/farmacologia , Quitosana/química , Humanos , Polpa Dentária/citologia , Polpa Dentária/metabolismo , Dentina/química , Dentina/metabolismo , Materiais Biocompatíveis/química , Células Cultivadas , Sobrevivência Celular/efeitos dos fármacos
4.
Clin Oral Investig ; 29(1): 70, 2025 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-39833560

RESUMO

OBJECTIVES: This study aimed to determine whether incorporating nanostructured additives into bleaching agents enhances efficacy and reduces side effects while identifying gaps for further investigation. METHODS: A comprehensive search was conducted in electronic databases, including PubMed/Medline, Embase, Scopus, and ISI Web of Science. Two reviewers independently screened articles based on predefined criteria, resolving discrepancies through discussion or consultation with a third reviewer. Data extraction focused on key details, including study design, interventions, and outcomes. RESULTS: Twenty-one articles were reviewed, consisting of nine clinical studies, one in vivo/in situ study, and 11 in vitro studies on tooth bleaching protocols. Hydrogen peroxide was the most commonly used bleaching agent. The primary nanostructured additives studied were titanium dioxide nanoparticles, polymeric carbamide peroxide nanoparticles, chitosan nanoparticles, nano-hydroxyapatite, SiO2/MgO/Fe2O3 nanocomposite spheres, and nano-bioactive glass. Most studies demonstrated an enhanced bleaching effect, reduced bleaching sensitivity, decreased cytotoxicity, reduced hydrogen peroxide penetration into the pulp chamber, and protection of the tooth surface against mineral and structural loss when nanostructured additives were incorporated into the bleaching agent. CONCLUSIONS: Incorporating nanostructured additives into tooth-bleaching agents improved efficacy and reduced side effects, especially with titanium oxide nanoparticles. Further clinical studies and systematic reviews are needed to establish strong evidence for safe clinical practice. CLINICAL RELEVANCE: Including nanostructured additives in bleaching agents, such as titanium oxide nanoparticles, might be a valuable approach to enhancing the bleaching potential while reducing bleaching sensitivity and cytotoxicity, offering safer alternatives for clinical protocols.


Assuntos
Peróxido de Hidrogênio , Nanoestruturas , Clareadores Dentários , Clareamento Dental , Humanos , Clareadores Dentários/química , Clareamento Dental/métodos , Titânio/química , Peróxido de Carbamida , Nanopartículas/química , Quitosana/química
5.
Molecules ; 30(2)2025 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-39860146

RESUMO

Scaffolds for regenerative therapy can be made from natural or synthetic polymers, each offering distinct benefits. Natural biopolymers like chitosan (CS) are biocompatible and biodegradable, supporting cell interactions, but lack mechanical strength. Synthetic polymers like polyvinyl alcohol (PVA) provide superior mechanical strength and cost efficiency but are not biodegradable or supportive of cell adhesion. Combining these polymers optimizes their advantages while adding metal oxide nanoparticles like calcium oxide (CaO NPs) enhances antimicrobial properties by damaging bacterial membranes. In this study, we obtained the formation of CaO NPs by calcinating eggshells, which were mixed in a polymeric network of CS and PVA to obtain four different membrane formulations for subdermal tissue regeneration. The spherical nanoparticles measured 13.43 ± 0.46 nm in size. Their incorporation into the membranes broadened the hydroxyl bands in the Fourier transform infrared (FTIR) analysis at 3331 cm⁻1. X-ray diffraction (XRD) analysis showed changes in the crystalline structure, with new diffraction peaks at 2θ values of 7.2° for formulations F2, F3, and F4, likely due to the increased amorphous nature and concentration of CaO NPs. Additionally, higher CaO NPs concentrations led to a reduction in thermal properties and crystallinity. Scanning electron microscopy (SEM) revealed a heterogeneous morphology with needle-like structures on the surface, resulting from the uniform dispersion of CaO NPs among the polymer chains and the solvent evaporation process. A histological examination of the implanted membranes after 60 days indicated their biocompatibility and biodegradability, facilitated by incorporating CaO NPs. During the degradation process, the material fragmented and was absorbed by inflammatory cells, which promoted the proliferation of collagen fibers and blood vessels. These findings highlight the potential of incorporating CaO NPs in soft tissue regeneration scaffolds.


Assuntos
Compostos de Cálcio , Quitosana , Nanopartículas , Óxidos , Álcool de Polivinil , Alicerces Teciduais , Quitosana/química , Álcool de Polivinil/química , Compostos de Cálcio/química , Alicerces Teciduais/química , Animais , Óxidos/química , Nanopartículas/química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier , Engenharia Tecidual/métodos , Difração de Raios X
6.
Biomacromolecules ; 26(2): 981-991, 2025 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-39814587

RESUMO

Polyamide (PA) has notable physical and chemical properties and is one of the most versatile synthetic materials in the industrial sector. However, its hydrophobicity creates significant challenges in its beneficiation and modification. Modifications of PA with chitosan nanoparticles (CNPs) can improve its undesired properties but are rarely found in the literature due to the weak interaction between the chemical groups of both structures. Surface hydrolysis mediated by enzymes can mildly improve the PA properties and create reactive sites. These sites can react with CNPs to confer enhanced properties to the fabrics, such as antimicrobial activity and flame retardancy. This study investigated the action of 14 hydrolases in the surface hydrolysis of 100% polyamide 6 (PA 6) fabric. Such an extensive study applying several enzymes for this process is uncommon. Under the optimum conditions, the hydrolyzed fabric was covalently bonded to the CNPs, generating material with reduced bacterial proliferation and flame retardancy properties. The uncommon covalent bond attachment achieved high material durability, even after five washing cycles.


Assuntos
Caprolactama , Quitosana , Nanopartículas , Quitosana/química , Hidrólise , Nanopartículas/química , Caprolactama/química , Caprolactama/análogos & derivados , Propriedades de Superfície , Polímeros/química , Interações Hidrofóbicas e Hidrofílicas , Têxteis , Nylons/química
7.
J Environ Manage ; 375: 124265, 2025 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-39884206

RESUMO

A hybrid composite (inorganic-organic) based on chitosan-functionalized hydrogen titanate nanotubes (TiCH) was synthesized by the hydrothermal method assisted by microwave, during 5h at 150 °C. The in-silico analysis determined the possible chitosan chemical adsorption models after calculating the Gibbs energies of their HOMO-LUMO orbitals. The TGA analysis confirmed the stability and helped to obtain the real functionalization degrees for the 3TiCH (2.22 %) and 5TiCH (4.33 %) samples, respectively. SEM images revealed that the 3TiCH and 5TiCH composites present tubular morphology that seemed covered with chitosan. The XRD patterns of 3TiCH and 5TiCH presented chitosan peaks, confirming their functionalization with chitosan anchored on the titanate surface. The photocatalytic degradation of ciprofloxacin antibiotic reached 93 % using the 3TiCH sample under 365-UV irradiation for 240 min. The photocatalytic performance of 3TiCH was 14.71 % more efficient than that of unfunctionalized TiNS after four reuses. The incorporation of the chitosan into the titanate improved the photocatalytic performance of the titanate, because it reduced its bandgap value, increasing the surface area, and boosting the adsorption capacity. A biopolymer such as chitosan in low concentrations can tailor the photoactivity of the inorganic nanomaterial to eliminate emerging contaminants contained in water bodies.


Assuntos
Quitosana , Ciprofloxacina , Fotólise , Quitosana/química , Ciprofloxacina/química , Adsorção , Titânio/química , Catálise
8.
J Agric Food Chem ; 73(2): 1097-1111, 2025 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-39748152

RESUMO

Polymer-based herbicide nanocarriers have shown potential for increasing the herbicide efficacy and environmental safety. This study aimed to develop, characterize, and evaluate toxicity to target and nontarget organisms of natural-based polymeric nanosystems for glyphosate. Polymers such as chitosan (CS), zein (ZN), and lignin (LG) were used in the synthesis. Nanosystem size, surface charge, polydispersity index, encapsulation efficiency, toxicity to weed species (Amaranthus hybridus, Ipomoea grandifolia, and Eleusine indica), and Roundup Ready (RR) crops, soil respiration, and enzyme activity were evaluated. The most stable system was the combination of ZN with the cross-linker poloxamer (PL), with higher weed control efficacy (90-96%) for A. hybridus, compared to commercial glyphosate (40%). No improvement was observed for I. grandifolia and E. indica. No glyphosate toxicity was observed in RR crops, soil respiration, or soil enzymes, indicating no toxic effects of the nanoformulation in these models. ZN-PL systems can be a promising alternative for glyphosate delivery, using environmentally friendly materials, with improved efficiency for weed control in agriculture.


Assuntos
Portadores de Fármacos , Glicina , Glifosato , Herbicidas , Glicina/análogos & derivados , Glicina/química , Glicina/toxicidade , Glicina/farmacologia , Herbicidas/química , Herbicidas/farmacologia , Portadores de Fármacos/química , Amaranthus/efeitos dos fármacos , Amaranthus/química , Controle de Plantas Daninhas , Eleusine/química , Eleusine/efeitos dos fármacos , Agricultura , Plantas Daninhas/efeitos dos fármacos , Polímeros/química , Quitosana/química , Nanopartículas/química , Zeína/química , Lignina/química
9.
Ciênc. rural (Online) ; 55(3): e20230164, 2025. tab, graf
Artigo em Inglês | VETINDEX | ID: biblio-1582077

RESUMO

Ensilage of rehydrated corn kernels (RC) has been used to improve nutritional value and facilitate on-farm storage. This study evaluated the effects of chitosan and lactic acid microbial inoculants on rehydrated corn silage microbiology, fermentation profile and losses, chemical composition, in vitro degradation, and aerobic stability. Forty experimental silos were used in a completely random design to evaluate the following treatments: 1) Control (CON): RC silage without additives; 2) Chitosan (CHI): RC silage with 6 g/kg dry matter (DM) of chitosan; 3) Lactobacillus buchneri (LB): RC ensiled with 5 × 105 colony forming units (CFU) of L. buchneri per gram fresh weight; and 4) Lactobacillus plantarum and Pediococcus acidilactici (LPPA): RC ensiled 1.6 × 105 of L. plantarum and 1.6 × 105 P. acidilactici per gram fresh weight. Additives increased lactic acid bacteria and concentration of lactic and propionic acid, decreased mold and yeast count and gas and fermentative losses, and improved DM recovery. The CHI-silos had lower silage pH, Ammonia-N concentration, fermentative losses, and higher acetic acid concentration compared to microbial inoculated-silos. In addition, CHI and LB decreased silage pH and temperature after aerobic exposure. Although, treatments showed slight effects on the nutritional value of RC, CHI improved aerobic stability and decreaseds fermentation losses.


A ensilagem de grãos de milho reidratados (RC) tem sido usada para melhorar o valor nutricional e facilitar o armazenamento na fazenda. Este estudo teve como objetivo avaliar os efeitos de inoculantes microbianos de quitosana e ácido lático na microbiologia de silagem de milho reidratada, perfil e perdas de fermentação, composição química, degradação in vitro e estabilidade aeróbia. Quarenta silos experimentais foram utilizados em delineamento inteiramente casualizado para avaliar os seguintes tratamentos: 1) Controle (CON): silagem RC sem aditivos; 2) Quitosana (CHI): silagem de RC com 6 g/kg de matéria seca (MS) de quitosana; 3) Lactobacillus buchneri (LB): RC ensilados com 5 × 105 unidades formadoras de colônias (UFC) de L. buchneri por grama na alimentação; e 4) Lactobacillus plantarum e Pediococcus acidilactici (LPPA): RC ensilado 1,6 × 105 de L. plantarum e 1,6 × 105 P. acidilactici por grama na alimentação. Os aditivos aumentaram as bactérias láticas e a concentração de ácido lático e propiônico, diminuíram a contagem de fungos e leveduras e as perdas gasosas e fermentativas e melhoraram a recuperação da MS. Os silos CHI apresentaram menores pH da silagem, concentração de N amoniacal, perdas fermentativas e maior concentração de ácido acético em comparação com silos inoculados microbianos. Além disso, CHI e LB reduziram pH e temperatura da silagem após a exposição ao ar. Embora os tratamentos mostrem pequenos efeitos sobre o valor nutricional do RC, a CHI melhoroua a estabilidade aeróbia e diminui as perdas por fermentação.


Assuntos
Silagem , Zea mays , Quitosana , Fermentação
10.
J Appl Microbiol ; 136(1)2025 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-39706671

RESUMO

AIMS: In this study, we report the use of two novel lytic polyvalent phages as a cocktail in in planta assays and their efficacy in the control of bacterial halo blight (BHB) caused by Pseudomonas coronafaciens pv. garcae (Pcg) in coffee plants. METHODS AND RESULTS: Phages were isolated from samples of coffee plant leaves collected at two different locations in Brazil. Both phages belong to the class Caudoviricetes and present myovirus-like morphotypes, and both exhibited specificity to their host, Pcg strain IBSBF-158. The two phages were encapsulated in chitosan-coated Ca-alginate nanoparticles, which demonstrated promising performance, promoting reductions in disease severity ranging from 66.83% to 83.37%, depending on the timing of application relative to infection. Both phages were somewhat susceptible to the effects of abiotic factors when in free form, with solar radiation seriously negatively impacting their lytic activity. However, nanoencapsulation of both phages as a lytic cocktail within chitosan-coated Ca-alginate nanoparticles proved successful in fully stabilizing both phages from the deleterious action of UV radiation. CONCLUSIONS: Application of such lytic nanoparticles in pre- and post-inoculated coffee seedlings in in planta greenhouse assays proved successful in controlling the phytopathogen responsible for BHB of coffee, Pcg, with a significant decrease in the progression of the disease. The results suggest that lytic nanoparticles may become an effective and sustainable strategy for coffee BHB control, as an alternative to conventional approaches relying on chemical (copper hydroxide or oxychloride or kasugamycin hydrochloride) or biological agents, but more studies are needed in the field to confirm this. The phage protection system developed represents a potential alternative treatment for bacterial plant diseases with minimum damage to the environment.


Assuntos
Nanopartículas , Doenças das Plantas , Pseudomonas , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Pseudomonas/virologia , Coffea/microbiologia , Quitosana , Bacteriófagos/fisiologia , Brasil , Folhas de Planta/microbiologia , Alginatos
11.
Biomed Mater ; 20(1)2024 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-39662035

RESUMO

Chitosan (CS) is a promising polymeric biomaterial for use in scaffolds forin vitroskin models and wound dressings, owing to its non-antigenic and antimicrobial properties. However, CS often exhibits insufficient physicochemical properties, mechanical strength, and bioactivity, limiting its efficacy in demanding applications. To address these challenges, cotton cellulose nanofibers (CNFs) represent a promising nanomaterial for enhancing CS-based scaffolds in tissue engineering. CNF offers superior stiffness, and mechanical properties that enhance cellular adhesion and proliferation, both crucial for effective tissue regeneration and healing. This study aimed to develop and characterize a scaffold combining cotton CNF and CS, focusing on its cytocompatibility with human fibroblasts and keratinocytes. The cotton CNF/CS scaffold was fabricated using the casting technique, and its physicochemical properties and cellular compatibility were assessedin vitro. The results demonstrated that incorporating cotton CNF significantly enhanced the stability of the CS matrix. The CS scaffold with 1000 µg ml-1of cotton CNF exhibited increased roughness and reduced rupture strain compared to the pure CS scaffold. The cotton CNF/CS scaffold effectively promoted the adhesion, viability, proliferation, migration, and collagen synthesis of skin cells. Notably, increased cell viability was observed in human fibroblasts cultured on scaffolds with higher concentrations of cotton CNF (100 and 1000 µg ml-1). Based on the findings, the cotton CNF/CS scaffold demonstrates enhanced physicochemical properties and bioactivity, making it a promising candidate for the development ofin vitrohuman skin models and wound healing dressings.


Assuntos
Materiais Biocompatíveis , Adesão Celular , Proliferação de Células , Sobrevivência Celular , Celulose , Quitosana , Fibroblastos , Queratinócitos , Nanofibras , Pele , Engenharia Tecidual , Alicerces Teciduais , Cicatrização , Quitosana/química , Cicatrização/efeitos dos fármacos , Humanos , Nanofibras/química , Engenharia Tecidual/métodos , Alicerces Teciduais/química , Fibroblastos/citologia , Celulose/química , Materiais Biocompatíveis/química , Queratinócitos/citologia , Teste de Materiais , Fibra de Algodão , Bandagens , Resistência à Tração , Colágeno/química
12.
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
13.
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
14.
J Food Sci ; 89(12): 8524-8538, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39495587

RESUMO

Peptides in black bean protein hydrolysates (BPHs) exert antioxidant capacity. However, peptides are prone to degradation during processing and digestion. Chitosan (Ch) can protect them and provide a delayed release. This work develops and compares two drying methods producing porous structured Ch microparticles (MPs) as carriers for antioxidant BPH. Ch gels were obtained by ionic gelation and dried by supercritical CO2 solvent displacement or fast-freeze-drying methods. The resulting aerogels and fast-freeze-dried MPs were structurally characterized, and their swelling and release profiles were obtained at pH 1.2 and 7.4. The antioxidant capacity of systems was determined by 2,2'-azino-bis(3-ethyl-benzthiazoline-6-sulphonic acid) (ABTS) and superoxide radical assays. The results showed BPH-Ch best complexation conditions occurring at a pH of 4.5 and a 4:1 BPH/Ch ratio. The particle size of the complex was 1047.6 nm, and the entrapment efficiency and loading capacity were 28.2% and 54.3%, respectively. At pH 1.2 and 7.4, the release rate of BPH was lower in aerogel than in fast-freeze-dried MPs. Besides, entrapment BPH in Ch significantly reduced the ABTS antioxidant activity IC50 from 35.1 µM Trolox equivalents (TE)/mg to 250.7 and 406.2 µM TE/mg for Ch fast-freeze-dried and aerogels, respectively. Superoxide radical inhibition IC50 ranged from 74.6 to 92.9 mM ascorbic acid equivalents/mg in the different samples. BPH-loaded aerogels presented lower specific surface area (94.7 vs. 138.6 m2/g, p < 0.05) and higher average pore size (26.4 vs. 19.8 nm) than Ch aerogels. Ch aerogel is a promising carrier for delaying the release of common bean antioxidant peptides useful for developing functional foods. PRACTICAL APPLICATION: This novel system could act as an ingredient to incorporate antioxidant compounds in different formats to develop delayed-release nutraceuticals and functional foods, such as bakery, dairy products, or beverages. Along, antioxidant peptide-loaded aerogels could be used as a slow-release system for compounds acting as natural preserving antioxidants for food applications such as raw meat products or high-fat foods.


Assuntos
Antioxidantes , Quitosana , Tamanho da Partícula , Hidrolisados de Proteína , Quitosana/química , Antioxidantes/farmacologia , Antioxidantes/química , Hidrolisados de Proteína/química , Proteínas de Plantas/química , Phaseolus/química , Liofilização , Concentração de Íons de Hidrogênio , Géis/química
15.
Int J Biol Macromol ; 283(Pt 4): 137749, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39577532

RESUMO

Proteases are a large group of enzymes in high demand due to their wide and different biotechnological applications mainly in the biomedical field. Ultrasound (US) has been used successfully in several Bioprocesses in biotechnology, such as in the upregulation of enzymatic hydrolysis (biocatalysis). The objective of this work was to purify an enzyme from Streptomyces parvulus and to characterize it through physic-chemical applications including ultrasound effect. The purified protease has a molecular weight of 78.0 KDa, a yield of 31 % and 11.8-fold, it was stable between pH 4-9, optimum pH at 7.5, temperature of 0-45 °C, and showed optimum temperature at 45 °C, exhibited enhanced activity with Ca2+ and Mg2+, and was inhibited by PMSF. US in the treatment or pre-treatment of enzymatic reactions showed to be favorable and increase the activity around 85 % for the optimum temperature 45 °C. Also, in circular dichroism spectra it was shown a significant change in enzyme structure under US effect enhancing the real activity. Besides, the US improved the enzyme reactions for all assays. The purified enzyme was successfully immobilized in chitosan film. Thus, the present work demonstrated the promising results of a protease with collagenolytic activity in the field of Biotechnology by proving the positive effect induced by ultrasound.


Assuntos
Fermentação , Peptídeo Hidrolases , Streptomyces , Temperatura , Streptomyces/enzimologia , Concentração de Íons de Hidrogênio , Peptídeo Hidrolases/isolamento & purificação , Peptídeo Hidrolases/química , Peptídeo Hidrolases/metabolismo , Estabilidade Enzimática , Ondas Ultrassônicas , Colágeno/química , Colágeno/metabolismo , Peso Molecular , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Quitosana/química , Hidrólise , Cinética
16.
ACS Appl Bio Mater ; 7(12): 8261-8271, 2024 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-39558637

RESUMO

Cationic lipid-based carriers are recognized for their ability to complex with mRNA and effectively deliver the mRNA for vaccination and therapeutic purposes. However, the significant cytotoxicity of these carriers often restricts their practical application. In the present study, polymer-lipid hybrid nanoparticles, termed chitosomes, incorporating chitosan-N-arginine (CSA) with the DOTAP cationic lipid and the DOPE helper lipid, were synthesized and evaluated. The addition of CSA to the lipid formulations improved their physicochemical stability and enhanced mRNA complexation, resulting in high transfection rates in the HeLa and HEK293T cell lines. However, the transfection efficiency was low in the NIH-3T3 cell line, indicating a cell type-specific response to chitosomes. Importantly, CSA significantly reduced the cytotoxicity typically associated with DOTAP. Overall, the present study indicated that optimizing the ratio of CSA to DOTAP is crucial for developing mRNA nanocarriers to achieve high transfection efficiency and reduce cytotoxicity across different cell lines.


Assuntos
Arginina , Materiais Biocompatíveis , Sobrevivência Celular , Quitosana , Teste de Materiais , Tamanho da Partícula , RNA Mensageiro , Quitosana/química , Humanos , Sobrevivência Celular/efeitos dos fármacos , RNA Mensageiro/metabolismo , Camundongos , Arginina/química , Arginina/farmacologia , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/síntese química , Animais , Células HEK293 , Células HeLa , Células NIH 3T3 , Nanopartículas/química , Transfecção , Estrutura Molecular
17.
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
18.
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
19.
Environ Sci Pollut Res Int ; 31(54): 62930-62949, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39466532

RESUMO

Due to its widespread use and incomplete breakdown in the human body, amoxicillin has been detected in receiving water bodies. This raises significant concerns, like the promotion of antibiotic resistance, toxicity towards aquatic life, disruption of the natural balance of microbial communities within these water bodies, and the struggle of effectively removal by the traditional wastewater treatment plants. Consequently, exploring new processes to complement the existing methods is crucial. Adsorption, a promising highly efficient, selective, and versatile technique, can effectively remove contaminants, making it useful in various industries such as water treatment, pharmaceuticals, and environmental remediation. Several adsorbents are documented in the literature for drug adsorption; however, their fabrication often involves more complex steps and substances compared to chitosan and alginate, which are natural polymers that are biocompatible, non-toxic, and biodegradable. Their tunable properties and ease of modification enhance their efficacy in environmental remediation. Therefore, the novelty of this article is to understand the interaction of amoxicillin with chitosan and alginate adsorbents easily synthetized using the dripping technique. This approach allows us to explore basic principles that can be applied to more complex systems in future studies. The optimal pH for both beads was found to be 4, with adsorption capacities of 74.2 ± 0.3 mg g-1 for alginate and 80.4 ± 0.2 mg g-1 for chitosan, using 1 g of adsorbent. Kinetics studies indicated that external diffusion governs adsorption for alginate, while internal diffusion governs adsorption for chitosan. This approach underscores the potential of chitosan and alginate beads as effective adsorbents for mitigating antibiotic contamination in water systems, offering a sustainable complement to traditional treatment methods.


Assuntos
Alginatos , Amoxicilina , Quitosana , Poluentes Químicos da Água , Quitosana/química , Amoxicilina/química , Alginatos/química , Adsorção , Biopolímeros/química , Poluentes Químicos da Água/química , Purificação da Água/métodos
20.
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
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