Complexos polieletrólitos de quitosana e xantana carregados com ativos naturais e sintéticos: estudo físico/químico e microbiológico para aplicação de drug delivery / Polyelectrolyte complexes of chitosan and xanthan loaded with natural and synthetic actives: physicochemical and microbiological study for drug delivery application

A eficácia dos implantes osseointegrados é amplamente reconhecida na literatura científica. Contudo, infiltrações bacterianas na junção implante-pilar podem desencadear inflamação nos tecidos circundantes, contribuindo para a evolução de condições mais sérias, como a peri-implantite. O objetivo desse estudo foi produzir complexos polieletrólitos (PECs) de quitosana (Q) e xantana (X) em forma de membranas, carregá-las com ativos naturais e sintéticos antimicrobianos, caracterizálas estruturalmente e avaliá-las frente a degradação enzimática, cinética de liberação e ações antimicrobianas com finalidade de aplicação para drug delivery. Membranas de QX a 1% (m/v) foram produzidas em três proporções, totalizando doze grupos experimentais: QX (1:1); QX (1:2), QX (2:1), QX-P (com própolis) (1:1); QX-P (1:2); QX-P (2:1); QX-C (com canela) (1:1); QX-C (1:2); QX-C (2:1) e CLX (com clorexidina 0,2%) (1:1); CLX (1:2); CLX (2:1). Para os estudos de caracterização foram feitas análises da espessura em estado seco; análises morfológicas superficial e transversal em Microscopia Eletrônica de Varredura (MEV); análise estrutural de espectroscopia de infravermelho por transformada de Fourier (FTIR); análise de degradação por perda de massa sob ação da enzima lisozima; e análise da cinética de liberação dos ativos em saliva artificial. Para os testes microbiológicos, análises de verificação de halo de inibição e ação antibiofilme foram feitas contra cepas de Staphylococcus aureus (S. aureus) e Escherichia coli (E. coli). Os resultados demonstraram que a espessura das membranas variou conforme a proporção, sendo que o grupo QX (1:2) apresentou a maior média de 1,022 mm ± 0,2, seguida respectivamente do QX (1:1) com 0,641 mm ± 0,1 e QX (2:1) com 0,249 mm ± 0,1. Nas imagens de MEV é possível observar uma maior presença de fibras, rugosidade e porosidade nos grupos QX (1:2) e QX (1:1) respectivamente, e, no QX (2:1) uma superfície mais lisa, uniforme e fina. No FTIR foram confirmados os picos característicos dos materiais isoladamente, além de observar as ligações iônicas que ocorreram para formação dos PECs. Na análise de degradação, os grupos com ativos naturais adicionados tiveram melhores taxas de sobrevida do que os grupos QX. No teste de liberação, os grupos QX-P tiveram uma cinética mais lenta que os QX-C, cuja liberação acumulada de 100% foi feita em 24 h. Já nos testes do halo inibitório, somente os grupos CLX tiveram ação sobre as duas cepas, e os QX-P tiveram sobre S. aureus. Nas análises antibiofilme, os grupos CLX apresentaram as maiores taxas de redução metabólica nas duas cepas (± 79%); os grupos QX-P apresentaram taxas de redução similares em ambas as cepas, porém com percentual um pouco maior para E. coli (60- 80%) e os grupos QX-C tiveram grande discrepância entre as duas cepas: de 35 a 70% para S. aureus e 14 a 19% para E. coli. Pode-se concluir que, frente as análises feitas, o comportamento do material foi afetado diretamente pelos ativos adicionados a matriz polimérica. As proporções de Q ou X afetaram somente a espessura final. Quanto a aplicação proposta de drug delivery, os dispositivos apresentaram grande potencial, principalmente os grupos CLX e QX-P. (AU)

The effectiveness of osseointegrated implants is widely recognized in scientific literature. However, bacterial infiltrations at the implant-abutment interface may trigger inflammation in surrounding tissues, contributing to the development of more serious conditions, such as peri-implantitis. The aim of this study was to produce chitosan (Q) and xanthan (X) polyelectrolyte complexes (PECs) in the form of membranes, load and evaluate them for enzymatic degradation, release kinetics, and antimicrobial actions for drug delivery applications. QX membranes at 1% (w/v) were produced in three proportions, totaling twelve experimental groups: QX (1:1), QX (1:2), QX (2:1), QX-P (with propolis) (1:1), QX-P (1:2), QX-P (2:1), QX-C (with cinnamon) (1:1), QX-C (1:2), QX-C (2:1), and CLX (with 0.2% chlorhexidine) (1:1), CLX (1:2), CLX (2:1). Characterization studies included analyses of dry state thickness, surface and crosssectional morphology using Scanning Electron Microscopy (SEM), structural analysis by Fourier Transform Infrared (FTIR) spectroscopy, mass loss degradation analysis under lysozyme action, and active release kinetics analysis in artificial saliva. Microbiological tests included verification analyses of inhibition halos and antibiofilm action against strains of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Results showed that membrane thickness varied according to proportion, with group QX (1:2) presenting the highest average of 1.022 mm ± 0.2, followed by QX (1:1) with 0.641 mm ± 0.1, and QX (2:1) with 0.249 mm ± 0.1. SEM images showed greater presence of fibers, roughness, and porosity in groups QX (1:2) and QX (1:1) respectively, while QX (2:1) exhibited a smoother, more uniform, and thinner surface. FTIR confirmed characteristic peaks of the materials individually, besides showing ionic bonds formed for PECs. Degradation analysis revealed that groups with added natural actives had better survival rates than QX groups. In release tests, QX-P groups exhibited slower kinetics than QX-C, with 100% cumulative release achieved in 24 h. inhibitory halo tests, only CLX groups exhibited action against both strains, while QX-P acted against S. aureus. Antibiofilm analyses showed CLX groups with the highest metabolic reduction rates in both strains (± 79%); QX-P groups showed similar reduction rates in both strains, slightly higher for E. coli (60-80%), and QX-C groups had a significant discrepancy between strains: 35-70% for S. aureus and 14-19% for E. coli. In conclusion, material behavior was directly affected by added actives to the polymeric matrix. Proportions of Q or X only affected final thickness. Regarding proposed drug delivery applications, the devices showed great potential, especially CLX and QX-P groups.(AU)

Study on injectable chitosan hydrogel with tendon-derived stem cells for enhancing rotator cuff tendon-to-bone healing / 中国修复重建外科杂志

OBJECTIVE@#To explore the effect of chitosan (CS) hydrogel loaded with tendon-derived stem cells (TDSCs; hereinafter referred to as TDSCs/CS hydrogel) on tendon-to-bone healing after rotator cuff repair in rabbits.@*METHODS@#TDSCs were isolated from the rotator cuff tissue of 3 adult New Zealand white rabbits by Henderson step-by-step enzymatic digestion method and identified by multidirectional differentiation and flow cytometry. The 3rd generation TDSCs were encapsulated in CS to construct TDSCs/CS hydrogel. The cell counting kit 8 (CCK-8) assay was used to detect the proliferation of TDSCs in the hydrogel after 1-5 days of culture in vitro, and cell compatibility of TDSCs/CS hydrogel was evaluated by using TDSCs alone as control. Another 36 adult New Zealand white rabbits were randomly divided into 3 groups ( n=12): rotator cuff repair group (control group), rotator cuff repair+CS hydrogel injection group (CS group), and rotator cuff repair+TDSCs/CS hydrogel injection group (TDSCs/CS group). After establishing the rotator cuff repair models, the corresponding hydrogel was injected into the tendon-to-bone interface in the CS group and TDSCs/CS group, and no other treatment was performed in the control group. The general condition of the animals was observed after operation. At 4 and 8 weeks, real-time quantitative PCR (qPCR) was used to detect the relative expressions of tendon forming related genes (tenomodulin, scleraxis), chondrogenesis related genes (aggrecan, sex determining region Y-related high mobility group-box gene 9), and osteogenesis related genes (alkaline phosphatase, Runt-related transcription factor 2) at the tendon-to-bone interface. At 8 weeks, HE and Masson staining were used to observe the histological changes, and the biomechanical test was used to evaluate the ultimate load and the failure site of the repaired rotator cuff to evaluate the tendon-to-bone healing and biomechanical properties.@*RESULTS@#CCK-8 assay showed that the CS hydrogel could promote the proliferation of TDSCs ( P<0.05). qPCR results showed that the expressions of tendon-to-bone interface related genes were significantly higher in the TDSCs/CS group than in the CS group and control group at 4 and 8 weeks after operation ( P<0.05). Moreover, the expressions of tendon-to-bone interface related genes at 8 weeks after operation were significantly higher than those at 4 weeks after operation in the TDSCs/CS group ( P<0.05). Histological staining showed the clear cartilage tissue and dense and orderly collagen formation at the tendon-to-bone interface in the TDSCs/CS group. The results of semi-quantitative analysis showed that compared with the control group, the number of cells, the proportion of collagen fiber orientation, and the histological score in the TDSCs/CS group increased, the vascularity decreased, showing significant differences ( P<0.05); compared with the CS group, the proportion of collagen fiber orientation and the histological score in the TDSCs/CS group significantly increased ( P<0.05), while there was no significant difference in the number of cells and vascularity ( P>0.05). All samples in biomechanical testing failed at the repair site during the testing process. The ultimate load of the TDSCs/CS group was significantly higher than that of the control group ( P<0.05), but there was no significant difference compared to the CS group ( P>0.05).@*CONCLUSION@#TDSCs/CS hydrogel can induce cartilage regeneration to promote rotator cuff tendon-to-bone healing.

Research progress of chitosan and quaternized chitosan as vaccine adjuvant / 中国生物制品学杂志

@#Adjuvant is the key factor for many new vaccines to play a protective role. The addition of adjuvant can not only reduce the amount of antigen,but also increase the immunogenicity of its antigen,and stimulate the strong immune response of body. Chitosan,as the product of natural polysaccharide chitin removing part of acetyl group,has the characteristics of adhesion,permeability,biocompatibility and so on,and has been widely studied and applied as a vaccine adjuvant. As a novel adjuvant,it can not only help to induce cellular and humoral immunity,but also activate mucosal immunity. This review discussed the recent progress of chitosan and quaternized chitosan as vaccine adjuvants and the related mechanism.

Development of chitosan based microencapsulated spray dried powder of tuna fish oil: oil load impact and oxidative stability

Abstract The impact of fish oil concentration on the oxidative stability of microcapsules through the spray drying process using chitosan and maltodextrin as wall material was studied. Emulsions were prepared with different Tuna fish oil (TFO) content (TFO-10%, TFO20%, TF030% TF0-40%) while wall material concentration was kept constant. Microencapsulated powder resulting from emulsion prepared with high fish oil load have high moisture content, wettability, total oil and low encapsulation efficiency, hygroscopicity and bulk tapped density. Oxidative stability was evaluated periodically by placing microcapsules at room temperature. Microcapsules prepared with TFO-10% presented high oxidative stability in terms of peroxide value (2.94±0.04) and anisidine value (1.54±0.02) after 30 days of storage. It was concluded that optimal amounts of fish oil for microencapsulation are 10% and 20% using chitosan and maltodextrin that extended its shelf life during study period.

Resumo Foi estudado o impacto da concentração de óleo de peixe na estabilidade oxidativa de microcápsulas por meio do processo de secagem por atomização, utilizando quitosana e maltodextrina como material de parede. As emulsões foram preparadas com diferentes teores de óleo de atum (TFO) (TFO-10%, TFO20%, TF030% TF0-40%), enquanto a concentração de material de parede foi mantida constante. O pó microencapsulado resultante da emulsão preparada com alta carga de óleo de peixe tem alto teor de umidade, molhabilidade e óleo total e baixa eficiência de encapsulação, higroscopicidade e densidade extraída a granel. A estabilidade oxidativa foi avaliada periodicamente colocando microcápsulas à temperatura ambiente. As microcápsulas preparadas com TFO-10% apresentaram alta estabilidade oxidativa em termos de valor de peróxido (2,94 ± 0,04) e valor de anisidina (1,54 ± 0,02) após 30 dias de armazenamento. Concluiu-se que as quantidades ideais de óleo de peixe para microencapsulação são de 10% e 20% usando quitosana e maltodextrina que prolongaram sua vida útil durante o período de estudo.

Development of chitosan based microencapsulated spray dried powder of tuna fish oil: oil load impact and oxidative stability / Desenvolvimento de pó microencapsulado por pulverização de óleo de atum à base de quitosana: impacto da carga de óleo e estabilidade oxidativa

Abstract The impact of fish oil concentration on the oxidative stability of microcapsules through the spray drying process using chitosan and maltodextrin as wall material was studied. Emulsions were prepared with different Tuna fish oil (TFO) content (TFO-10%, TFO20%, TF030% TF0-40%) while wall material concentration was kept constant. Microencapsulated powder resulting from emulsion prepared with high fish oil load have high moisture content, wettability, total oil and low encapsulation efficiency, hygroscopicity and bulk tapped density. Oxidative stability was evaluated periodically by placing microcapsules at room temperature. Microcapsules prepared with TFO-10% presented high oxidative stability in terms of peroxide value (2.94±0.04) and anisidine value (1.54±0.02) after 30 days of storage. It was concluded that optimal amounts of fish oil for microencapsulation are 10% and 20% using chitosan and maltodextrin that extended its shelf life during study period.

Resumo Foi estudado o impacto da concentração de óleo de peixe na estabilidade oxidativa de microcápsulas por meio do processo de secagem por atomização, utilizando quitosana e maltodextrina como material de parede. As emulsões foram preparadas com diferentes teores de óleo de atum (TFO) (TFO-10%, TFO20%, TF030% TF0-40%), enquanto a concentração de material de parede foi mantida constante. O pó microencapsulado resultante da emulsão preparada com alta carga de óleo de peixe tem alto teor de umidade, molhabilidade e óleo total e baixa eficiência de encapsulação, higroscopicidade e densidade extraída a granel. A estabilidade oxidativa foi avaliada periodicamente colocando microcápsulas à temperatura ambiente. As microcápsulas preparadas com TFO-10% apresentaram alta estabilidade oxidativa em termos de valor de peróxido (2,94 ± 0,04) e valor de anisidina (1,54 ± 0,02) após 30 dias de armazenamento. Concluiu-se que as quantidades ideais de óleo de peixe para microencapsulação são de 10% e 20% usando quitosana e maltodextrina que prolongaram sua vida útil durante o período de estudo.

Vestibuloplastia con láser de Er Cr:YSGG y nanotransportador biomolécula EPX: un nuevo cicatrizante periodontal / Vestibuloplasty with Er Cr:YSGG laser and EPX biomolecule nanocarrier: a new periodontal healing agent

La resorción ósea alveolar suele dar lugar a que las inserciones de la mucosa interfieran para la construcción, estabilidad y retención de una prótesis removible, una opción que permite modificar este tejido se obtiene por medio de una vestibuloplastia. Actualmente se puede favorecer la cicatrización de heridas utilizando láser de alta potencia aplicado a procedimientos quirúrgicos orales. Se realiza reporte de caso en paciente femenino a la que se realizó procedimiento de vestibuloplastia con láser de Er,Cr:YSGG, utilizando de forma postoperatoria gel de quitosano en nanotransportador biomolécula EPX. Se observa una cicatrización rápida y favorable al combinar ambas terapéuticas, además al utilizar productos con quitosano se disminuye el riesgo de la necrosis de fibroblastos gingivales humanos como recientemente se reportó en el uso de colutorios de clorhexidina (AU)

Alveolar bone resorption often results in mucosal insertions interfering with the construction, stability and retention of a removable prosthesis, an option to modify this tissue is obtained by means of vestibuloplasty. Currently, wound healing can be promoted by using high power laser applied to oral surgical procedures. A case report of a female patient who underwent a vestibuloplasty procedure with laser Er,Cr:YSGG, using chitosan gel with EPX biomolecule nanocarriers postoperatively. A fast and favorable healing is observed when combining both therapeutics, besides, when using products with chitosan, the risk of necrosis of human gingival fibroblasts is reduced, as recently reported in the use of chlorhexidine mouthwashes (AU)

Estudio de biocompatibilidad de matrices poliméricas combinadas, responsivas al pH, con aplicación en Ingeniería de Tejido Óseo / Biocompatibility study of combined pH-responsive polymeric matrices with application in Bone Tissue Engineering

El presente trabajo muestra la obtención de un material a partir de un polímero sintético (TerP) y otro natural, mediante entrecruzamiento físico y su caracterización fisicoquímica y biológica, con el fin de emplearlos para regeneración de tejido óseo. Las membranas fueron obtenidas por la técnica de evaporación del solvente y caracterizadas por espectroscopia FTIR, ensayos de hinchamiento, medidas de ángulo de contacto y microscopia electrónica de barrido (SEM). Se encontró que la compatibilidad entre los polímeros que la constituyen es estable a pH fisiológico y que, al incorporar mayor cantidad del TerP a la matriz, esta se vuelve más hidrofóbica y porosa. Además, teniendo en cuenta la aplicación prevista para dichos materiales, se realizaron estudios de biocompatibilidad y citotoxicidad con células progenitoras de médula ósea (CPMO) y células RAW264.7, respectivamente. Se evaluó la proliferación celular, la producción y liberación de óxido nítrico (NO) al medio de cultivo durante 24 y 48 horas y la expresión de citoquinas proinflamatorias IL-1ß y TNF-α de las células crecidas sobre los biomateriales variando la cantidad del polímero sintético. Se encontró mayor proliferación celular y menor producción de NO sobre las matrices que contienen menos proporción del TerP, además de poseer una mejor biocompatibilidad. Los resultados de este estudio muestran que el terpolímero obtenido y su combinación con un polímero natural es una estrategia muy interesante para obtener un biomaterial con posibles aplicaciones en medicina regenerativa y que podría extenderse a otros sistemas estructuralmente relacionados. (AU)

In the present work, the preparation of a biomaterial from a synthetic terpolymer (TerP) and a natural polymer, physically crosslinked, is shown. In order to evaluate the new material for bone tissue regeneration, physicochemical and biological characterizations were performed. The membranes were obtained by solvent casting and characterized using FTIR spectroscopy, swelling tests, contact angle measurements, and scanning electron microscopy (SEM). It was found that the compatibility between the polymers is stable at physiological pH and the incorporation of a higher amount of TerP into the matrix increases hydrophobicity and porosity.Furthermore, considering the intended application of these materials, studies of biocompatibility and cytotoxicity were conducted with Bone Marrow Progenitor Cells (BMPCs) and RAW264.7 cells, respectively. Cell proliferation, NO production and release into the culture medium for 24 and 48 hours, and proinflammatory cytokine expression of IL-1ß and TNF-α from cells grown on the biomaterials while varying the amount of the synthetic polymer were evaluated. Greater cell proliferation and lower NO production were found on matrices containing a lower proportion of TerP, in addition to better biocompatibility. The results of this study demonstrate that the obtained terpolymer and its combination with a natural polymer is a highly interesting strategy for biomaterial preparation with potential applications in regenerative medicine. This approach could be extended to other structurally related systems. (AU)

Electrochemical Studies of Magnesium Coated with Modified Chitosan and Electrosprayed as an Anticorrosive Protection Method in Bone Repair / Estudios Electroquímicos del Magnesio Recubierto con Quitosano Modificado y Electrorociado como Proceso de Protección Anticorrosiva en la Reparación de Hueso

ABSTRACT Magnesium (Mg) is essential for the metabolic reactions of the human body and is known for its biocompatibility, its mechanical and physical properties are similar to human bone, which is why it is considered to have high potential in biomedical applications such as temporary and resorbable implants. Through surface modifications, the high tendency to corrosion of Mg could be controlled, such as biodegradable membranes that prevent the passage of chloride ions present in the human organism. To prepare the membrane, solutions of chitosan modified with gelatin and/or glutaraldehyde are used and by means of the electrospray method applied to protect the Mg. To simulate body fluid conditions a Kokubo saline solution (BFK) was prepared. The study focuses on evaluating the corrosion rate of Mg with a coating made of a chitosan electrosprayed membrane, applying electrochemical measurements of electrochemical impedance spectroscopy and linear polarization resistance. The key additive to improve the behavior of the membranes was observed with the use of gelatin, where the membrane with the best results lowing corrosion rates is the Mg CH+GE+GL system, which it was observed with very good physical integrity in the images of morphological analyzes of the surface after 30 days of exposure.

RESUMEN El magnesio (Mg) es esencial para las reacciones metabólicas del cuerpo humano y es conocido por su biocompatibilidad, sus propiedades mecánicas y físicas son similares a las del hueso humano, por lo que se considera que tiene un alto potencial en aplicaciones biomédicas como implantes temporales y reabsorbibles. Mediante modificaciones superficiales se podría controlar la alta tendencia a la corrosión del Mg, como por ejemplo membranas biodegradables que impidan el paso de iones cloruro presentes en el organismo humano. Para preparar la membrana se utilizan soluciones de quitosano modificado con grenetina y/o glutaraldehído y mediante el método de electrorociado se aplican para proteger el Mg. Para simular las condiciones de los fluidos corporales se preparó una solución salina de Kokubo. El estudio se enfoca en evaluar la velocidad de corrosión del Mg con un recubrimiento hecho de una membrana electrorociada con quitosano, aplicando técnicas electroquímicas de espectroscopia de impedancia electroquímica y resistencia de polarización lineal. El aditivo clave para mejorar el comportamiento de las membranas se observó con el uso de gelatina, donde la membrana con mejores resultados bajando los índices de corrosión es el sistema Mg CH+GR+GL, el cual se observó con muy buena integridad física en las imágenes de análisis morfológicos de la superficie después de 30 días de exposición.

Recubrimiento biodegradable antifúngico a base de quitosano y aceite esencial de cítricos para la conservación de papaya (Carica papaya L.) en poscosecha / Biodegradable antifungal coating based on chitosan and citrus essential oil for the conservation of papaya (Carica papaya L.) in postharvest

RESUMEN La papaya es una fruta climatérica altamente perecedera. La antracnosis, enfermedad provocada por hongos, es una de las principales causas de pérdida poscosecha. La actividad de extractos vegetales ha permitido la inhibición del desarrollo de microorganismos, en particular se ha reportado la actividad antifúngica de aceites esenciales. El objetivo de la presente investigación fue evaluar el efecto de un recubrimiento biodegradable a base de quitosano con aceite esencial de cítricos, aplicado en etapa poscosecha, en las propiedades físicoquímicas, fisiológicas e inhibición del crecimiento del hongo Colletotrichum gloeosporioides en frutos de papaya (Carica papaya L.). El recubrimiento se preparó con quitosano, glicerol, ácido acético, aceite esencial de Citrus reticulata (0.5 %, 1.0 % y 1.5 %) y Tween® 80. La solución se aplicó con una brocha en la epidermis de los frutos de papaya y se almacenaron a temperatura ambiente (24 °C ± 2 °C) por 10 d, junto con los frutos testigo. Las variables evaluadas en los frutos fueron color, pH, sólidos solubles totales (SST), firmeza, pérdida de peso, producción de CO2, de etileno y daño por antracnosis. Se utilizó un modelo estadístico completamente al azar. Los datos se sometieron al análisis de varianza (ANOVA) y comparación de medias por la prueba de Tukey (P < 0.05). El recubrimiento aplicado retrasó el cambio de color de la epidermis de los frutos de papaya, la pérdida de peso, firmeza y SST respecto a los frutos testigo. Los cambios estuvieron asociados a la modificación de la tasa de respiración y de producción de etileno de los frutos con recubrimiento. La matriz del quitosano conteniendo aceites escenciales, usada como recubrimiento, mejoró significativamente la vida de anaquel de la papaya y disminuyó más del 80 % el daño por antracnosis.

ABSTRACT Papaya is a highly perishable climacteric fruit. Anthracnose, a disease provoked by fungus, is one of the main causes of postharvest losses. The activity of plant extracts has allowed the inhibition of the development of microorganisms; in particular, the antifungal activity of essential oils has been reported. The aim of this research was to evaluate the effect of a biodegradable antifungal coating based on chitosan with citrus essential oil in the physicochemical and physiological properties and the antifungal activity of postharvest papaya (Carica papaya L.). The coating was prepared with chitosan, glycerol, acetic acid, essential oil of Citrus reticulata (0.5 %, 1.0 % and 1.5 %) and Tween® 80. The solution was applied with a brush to the epidermis of the postharvest papaya fruits and stored at room temperature (24 °C ± 2 °C) for 10 d. The variables evaluated in the fruits were color, pH, °Brix, firmness, weight loss, production of CO2 and ethylene and anthracnose damage. An analysis of variance (ANOVA) was performed under a completely randomized design and a comparison of Tukey means (P < 0.05). The coating applied delayed the color change of the epidermis of the papaya fruits, these maintained the high firmness values with respect to the control fruits. The changes were associated with the modification of the respiration rate and ethylene production of the coated fruits. The chitosan matrix containing essential oils used as a coating significantly improved shelf life of papaya and decreased anthracnose damage by 80 %.

Formulation and evaluation of Buccal mucoadhesive tablets of diclofenac sodium using 23 factorial designs

Buccal tablets

Diclofenac sodium

Drug release

Mucoadhesion

Mucoadhesive tablets

Release kinetics

Effects of Chitosan Nanoparticles with Long Synthetic siRNAs Targeting VEGF in Triple-Negative Breast Cancer Cells

Abstract Vascular endothelial growth factor (VEGF) is an essential angiogenic factor in breast cancer development and metastasis. Small interfering RNAs (siRNAs) can specifically silence genes via the RNA interference pathway, therefore were investigated as cancer therapeutics. In this study, we investigated the effects of siRNAs longer than 30 base pairs (bp) loaded into chitosan nanoparticles in triple-negative breast cancer cells, compared with conventional siRNAs. 35 bp long synthetic siRNAs inhibited VEGF gene expression by 51.2% and increased apoptosis level by 1.75-fold in MDA-MB-231 cell lines. Furthermore, blank and siRNA-loaded chitosan nanoparticles induced expression of IFN-γ in breast cancer cells. These results suggest that long synthetic siRNAs can be as effective as conventional siRNAs, when introduced into cells with chitosan nanoparticles

Chitosan microparticles loaded with essential oils inhibit duo-biofilms of Candida albicans and Streptococcus mutans

Abstract Oral candidiasis is a common fungal infection that affects the oral mucosa, and happens when Candida albicans interacts with bacteria in the oral microbiota, such as Streptococcus mutans, causing severe early childhood caries. C. albicans and S. mutans mixed biofilms are challenging to treat with conventional antimicrobial therapies, thus, new anti-infective drugs are required. Objective This study aimed to test a drug delivery system based on chitosan microparticles loaded with geranium and lemongrass essential oils to inhibit C. albicans and S. mutans mixed biofilms. Methodology Chitosan microparticles loaded with essential oils (CM-EOs) were obtained by spray-drying. Susceptibility of planktonic were performed according CLSI at 4 to 2,048 µg/mL. Mixed biofilms were incubated at 37ºC for 48 h and exposed to CM-EOs at 256 to 4,096 µg/mL. The antimicrobial effect was evaluated using the MTT assay, with biofilm architectural changes analyzed by scanning electron microscopy. RAW 264.7 cell was used to evaluate compound cytotoxicity. Results CM-EOs had better planktonic activity against C. albicans than S. mutans. All samples reduced the metabolic activity of mixed C. albicans and S. mutans biofilms, with encapsulated oils showing better activity than raw chitosan or oils. The microparticles reduced the biofilm on the slides. The essential oils showed cytotoxic effects against RAW 264.7 cells, but encapsulation into chitosan microparticles decreased their toxicity. Conclusion This study demonstrates that chitosan loaded with essential oils may provide an alternative method for treating diseases caused by C. albicans and S. mutans mixed biofilm, such as dental caries.

Novo sistema de liberação de drogas ­ filme de fibroína de seda carregado ou não com insulina para reparo de feridas em mucosa palatina: estudo in vitro e clínico randomizado / A new drug delivery system ­ silk fibroin film loaded or not with insulin on palatal mucosa wound healing: in vitro study and a randomized clinical trial

Several types of periodontal and peri-implant soft tissue defects require surgical treatment to reestablish function and aesthetics. However, local, and systemic factors can jeopardize tissue repair leading to unexpected outcomes and postoperative discomfort. In order to overcome this problem, new devices have been developed to improve surgical procedures outcomes and patient experience. The aim of the present study was to develop a new silk fibroin (SF)/chitosan (CH) film loaded with insulin as a drug delivery system to improve palatal donor area healing after free gingival graft harvesting for ridge preservation. For this, biomaterial development, characterization and in vitro assessment were performed to evaluate the new delivery system. In addition, 3- months outcomes from palatal wound healing following the use of the proposed delivery system were assessed through clinical, patient centered parameters, immunological, microbiological, and histological evaluations. Sixty-nine patients with indication of tooth extraction were enrolled into 3 groups: Control Group (C) (n=23): open wound on palatal mucosa followed by spontaneous healing; SF/CH Film (F) (n=23): open wound on palatal mucosa and silk fibroin film as dressing; Insulin-loaded SF/CH film (IF) (n=23): open wound on palatal mucosa and an insulin- loaded silk fibroin film as a delivery system. : It was verified some characteristics that are favorable to the oral environment, such as mechanical properties, swelling and permeability to water vapor. The biomaterial presented a standard of a controlled release system through diffusion with delivery stability in human saliva, along with an excellent biocompatibility with the absence of cytotoxicity and genotoxicity increasing cell viability in lineage cells (HaCat). F and IF promoted accelerated palatal wound closure on day 7 and 14 after surgery, as well as an early epithelialization, compared to the C group. Both films were capable to reduce pro-inflammatory cytokines (IL-6, TNF-α, IL-1ß) and modulate biomarkers correlated to tissue degradation/remodeling. Spontaneous healing microbiome reported higher genus/species with pathogenic role in the oral mucosa with reduction in health species following this profile until de end of the follow-up. A tendency of eubiosis was observed in F and IF groups throughout healing process. It seems that this new device has a promising application in oral cavity and positively influence wound healing. (AU)

Diversos tipos de defeitos mucogengivais requerem abordagem cirúrgica para o reestabelecimento funcional e estético. Porém, alterações locais e sistêmicas podem prejudicar o processo de reparo gerando resultados inesperados e desconforto ao paciente. Biomateriais vem sendo desenvolvidos para melhorar os resultados dos procedimentos cirúrgicos e a experiência clínica do paciente. O objetivo do presente estudo foi desenvolver um filme de fibroína de seda (FS) e quitosana (QT) carregado com insulina (INS), atuando como um sistema de liberação, para acelerar a cicatrização de feridas na área doadora palatina após procedimento de preservação de rebordo com uso de enxerto gengival livre. Para isso, foi executado o desenvolvimento, caracterização e avaliação in vitro do biomaterial. Ademais, o resultado de 3 meses do reparo das feridas palatinas foi verificado por meio de avaliações clínicas, imunológica, microbiológica, histológica, bem como parâmetros centrados no paciente. Sessenta e nove pacientes foram alocados aleatoriamente nos grupos Controle (C) (n=23): ferida aberta em palato seguido de cicatrização espontânea; Filme de FS/QT (F) (n=23): ferida aberta em palato associada ao filme na área doadora; Filme de FS/QT carregado com INS (IF) (n=23): ferida aberta em palato associada ao filme carregado com INS na área doadora. Verificou-se propriedades mecânicas, bem como de entumecimento e permeabilidade ao vapor de água, favoráveis ao meio bucal sem nenhuma alteração com a inclusão da INS. O dispositivo apresentou liberação controlada por meio de difusão com estabilidade em saliva humana. Excelente biocompatibilidade com ausência de cito e genotoxicidade foi observada em diversos tipos celulares aumentando a viabilidade celular em células de linhagem (HaCat). F e IF favoreceram um fechamento acelerado da ferida palatina aos 7 e 14 dias pós-injuria, assim como uma epitelização precoce destes comparado ao grupo C. F e IF reduziram citocinas pró-inflamatórias (IL6, TNF-α, IL-1ß) além de apresentarem função modulatória na quantificação de biomarcadores relacionados a degradação tecidual. O Grupo C apresentou gênero/espécies com potencial patogênico e redução de microrganismos relacionados a saúde mantendo este perfil aos 14 e 30 dias. Enquanto isso, uma tendência a eubiose foi observado em F e IF ao longo do processo de cicatrização. Deste modo, verifica-se a aplicação promissora do novo dispositivo na cavidade oral bem como capacidade de influenciar positivamente o reparo da mucosa oral. (AU)

Longitudinal analyses of composite resin restoration on erosive lesions: effect of dentin treatment with a chitosan nanoformulation containing green tea

Aim To evaluate the influence of the biomodification of erosive lesions with a chitosan nanoformulation containing green tea (NanoCsQ) on the clinical performance of a composite resin. Methods The study was performed in a split-mouth, randomized and double-blinded model with 20 patients with 40 erosive lesions. The patient's teeth were randomized into two groups (n=20) according to the surface treatment: 1) Without biomodification (control), and 2) Biomodification with NanoCsQ solution (experimental). The lesions were restored with adhesive (Tetric N-bond, Ivoclar) and composite resin (IPS Empress Direct, Ivoclar). The restorations were polished and 7 days (baseline), 6 months, and 12 months later were evaluated according to the United States Public Health Service (USPHS) modified criteria, using clinical exam and photographics. Data were analyzed by Friedman's and Wilcoxon signed-rank tests. Results No significant differences were found between the control and experimental groups (p=0.423), and also among the follow-up periods (baseline, six months, and 12 months) (p=0.50). Regarding the retention criteria, 90% of the restoration had an alpha score in the control group. Only 10% of the restorations without biomodification (control) had a score charlie at the 12-month follow-up. None of the patients reported post-operatory sensitivity. Conclusion The NanoCsQ solution did not negatively affect the performance of the composite resin restorations after 12 months.

Assessment of the regenerative potential of macro-porous chitosan-calcium simvastatin scaffolds on bone cells

Abstract This study evaluated the bioactive potential of a macro-porous chitosan scaffold incorporated with calcium hydroxide (CH-Ca) and functionalized with bioactive doses of simvastatin (SV) for bone tissue regeneration. Initially, the bioactive dose of SV in osteoblastic cells (SAOS-2) was determined. For the direct contact experiment, SAOS-2 cells were plated on scaffolds to assess cell viability and osteogenic differentiation. The second assay was performed at a distance using extracts from scaffolds incubated in culture medium to assess the effect of conditioned medium on viability and osteogenic differentiation. The initial screening showed that 1 μM SV presented the best biostimulating effects, and this dose was selected for incorporation into the CH-Ca and pure chitosan (CH) scaffolds. The cells remained viable throughout the direct contact experiment, with the greatest cell density in the CH-Ca and CH-Ca-SV scaffolds because of their higher porosity. The CH-Ca-SV scaffold showed the most intense bio-stimulating effect in assays in the presence and absence of osteogenic medium, leading to an increased deposition of mineralized matrix. There was an increase in the viability of cells exposed to the extracts for CH-Ca, CH-SV, and CH-Ca-SV during the one-day period. There was an increase in ALP activity in the CH-Ca and CH-Ca-SV; however, the CH-Ca-SV scaffold resulted in an intense increase in the deposition of mineralized nodules, approximately 56.4% at 7 days and 117% at 14 days, compared with CH (control). In conclusion, functionalization of the CH-Ca scaffold with SV promoted an increase in bioactivity, presenting a promising option for bone tissue regeneration.

An experimental study on the biological characteristics of SDF-1/CS/β-GP composite bio-membrane in vitro / 口腔医学

Objective@#To prepare a composite membrane by chitosan/β-sodium glycerophosphate(CS/β-GP) thermosensitive hydrogel combined with stromal cell derived factor-1(SDF-1) and observe its biological characteristics in vitro.@*Methods@#Different doses of SDF-1 were added into CS/β-GP solution and then the thermosensitive gel time was measured. The SDF-1/CS/β-GP solution was membrane paved and dried to prepare composite membranes. The morphological characteristics were observed by scanning electron microscope(SEM). Composite membranes were placed into cell culture medium, and the supernatant(n=3) was extracted after standing at 6, 12, 24, 36, 48, 60 h, respectively. The concentration of SDF-1 in the solution was measured. Bone mesenchymal stem cells(BMSCs) were cultured in the Transwell room, and the composite membranes containing different concentrations of SDF-1 were placed in the lower chamber. There were four groups(n=3): Group M0 used CS/β-GP membrane(control group), Group M1, M2, M3 used SDF-1/CS/β-GP membrane(SDF-1 was 100, 200, 400 ng/mL respectively). After culture for 6, 12 and 24 h, the cells under the membrane were preserved and Giemsa stained and counted. The absorbance(OD) value was measured by MTT method to calculate the cell proliferation rate. SPSS 19.0 was used for multi-factor analysis of variance.@*Results @#After adding a certain amount of SDF-1 into CS/β-GP solution, the gel time did not change significantly(P>0.05). The SDF-1/CS/β-GP membrane was translucent and porous at 37 ℃. In this experiment, the volumic mass of SDF-1 released by SDF-1/CS/β-GP composite membrane increased gradually with the experimental time(P<0.01). Transwell cell chemotaxis test showed that the number of BMSCs cells with directional migration increased with the prolongation of observation time(P<0.01) and the increase of SDF-1 volumic mass(P<0.01). In MTT test, the OD value of migration cell solution increased with the prolongation of time(P<0.01) and the increase of SDF-1 volumic mass(P<0.01). @*Conclusion@# The SDF-1/CS/β-GP composite membrane has a porous structure and biological activity of chemotactic BMSCs directional migration. It is a potential membrane for guided tissue regeneration.

Applicatoin of chitosan-based hydrogel in oral tissue engineering / 中南大学学报(医学版)

Pulpitis, periodontitis, jaw bone defect, and temporomandibular joint damage are common oral and maxillofacial diseases in clinic, but traditional treatments are unable to restore the structure and function of the injured tissues. Due to their good biocompatibility, biodegradability, antioxidant effect, anti-inflammatory activity, and broad-spectrum antimicrobial property, chitosan-based hydrogels have shown broad applicable prospects in the field of oral tissue engineering. Quaternization, carboxymethylation, and sulfonation are common chemical modification strategies to improve the physicochemical properties and biological functions of chitosan-based hydrogels, while the construction of hydrogel composite systems via carrying porous microspheres or nanoparticles can achieve local sequential delivery of diverse drugs or bioactive factors, laying a solid foundation for the well-organized regeneration of defective tissues. Chemical cross-linking is commonly employed to fabricate irreversible permanent chitosan gels, and physical cross-linking enables the formation of reversible gel networks. Representing suitable scaffold biomaterials, several chitosan-based hydrogels transplanted with stem cells, growth factors or exosomes have been used in an attempt to regenerate oral soft and hard tissues. Currently, remarkable advances have been made in promoting the regeneration of pulp-dentin complex, cementum-periodontium-alveolar bone complex, jaw bone, and cartilage. However, the clinical translation of chitosan-based hydrogels still encounters multiple challenges. In future, more in vivo clinical exploration under the conditions of oral complex microenvironments should be performed, and the combined application of chitosan-based hydrogels and a variety of bioactive factors, biomaterials, and state-of-the-art biotechnologies can be pursued in order to realize multifaceted complete regeneration of oral tissue.

Evaluation of immune effect of diphtheria toxoid vaccine with chitosan as adjuvant on mice / 中国生物制品学杂志

@#Objective To evaluate the immune effect of the diphtheria toxoid(DT)vaccine using chitosan as adjuvant on mice,so as to provide an experimental basis for the preparation of novel adjuvant vaccines of DT.Methods A total of 30 male C57BL/6 mice were divided into mucosal immunization group and humoral immunization group,and each group was randomly divided into 6 groups:negative control group(PBS),positive control group(DT),aluminum adjuvant group,chitosan adjuvant group(final solution with 0.5% chitosan),aluminum adjuvant vaccine group and chitosan adjuvant vaccine group,with 5 mice in each group. Mucosal immunization group and humoral immunization group were inoculated with 500 μL PBS buffer,10 μg DT,500 μg aluminum adjuvant and 500 μL chitosan adjuvant per mouse by nasal drip and intraperitoneal injection respectively. The mice were observed for the status,collected for the eyeball serum before inoculation(0 d)and 7,21,35 d after inoculation,and collected for the nasal lotion simultaneously. The levels of IgG antibody in serum and sIgA antibody in nasal lotion were detected by ELISA.Results After intraperitoneal injection and nasal drip of chitosan adjuvant vaccine,the mental and behavioral state of mice was normal. Chitosan adjuvant vaccine effectively induced the IgG antibody against diphtheria in mice with not significant difference,compared with the classic aluminum adjuvant vaccine group(F = 127.926 > F_(0.05(1,8)),P > 0.05);It also induced the production of sIgA in mice,which was significantly higher than that in the classical aluminum adjuvant vaccine group 21 d after immunization(F =127.926 > F_(0.05(1,8)),P < 0.05).Conclusion Chitosan adjuvant DT vaccine can effectively stimulate the mucosal immunity and humoral immunity in mice with good safety,and has the potential to be an alternative to aluminum adjuvant for vaccine preparation,which can be considered as nasal drop vaccines.

Preparation and performance evaluation on chitosan/gelatin hydrogel hemostatic material containing Panax notoginseng / 国际生物医学工程杂志

Objective:To prepare chitosan/gelatin hydrogel composite hemostatic materials loaded with Panax notoginseng (PN/CMC/GMs) and evaluate their performance. Methods:PN/CMC/GMs hydrogel composite hemostatic material were prepared by the freeze-drying method, and their morphology was observed by scanning electron microscopy. Their rheological properties were observed by a rheometer. Their water absorption rate was tested by dissolution. Their biocompatibility was detected by a cytotoxicity assay. Their rapid hemostatic effect was tested using a SD rat liver hemorrhage model.Results:PN/CMC/GMs composite hemostatic materials were prepared in a lattice-like structure with certain porosity. With the increase in Panax notoginseng powder content, the modulus of PN/CMC/GMs increased accordingly, and the mechanical strength increased. PN/CMC/GMs have better water absorption and expansion functions, which can form compression hemostasis and concentrated blood to achieve rapid hemostasis, and have good biocompatibility. Hemostasis experiments showed that the hemostatic time and hemostatic effect of PN, CMC/GMs hemostatic materials on liver injury in rats were better than those of the blank control group. Conclusions:PN/CMC/GMs have good hemostatic effect and biocompatibility and have the potential for further research and clinical application.

Preparation of chitosan hydrochloride stabilized emulsion and its immunostimulatory effect / 生物工程学报

In order to increase the ability of oil-emulsion adjuvant to stimulate cellular immunity, chitosan hydrochloride with positive charge was selected to stabilize oil-in-water emulsion (CHE). In this paper, model antigen ovalbumin was selected to prepare vaccines with emulsion adjuvant, commercial adjuvant or no adjuvant. The emulsion was characterized by measuring the particle size, electric potential and antigen adsorption rate. BALB/c mice were immunized by intramuscular injection. Serum antibody levels, the numbers of IL-4-secreting cells in splenocytes, cytotoxic T lymphocyte (CTL) response, and the expression of central memory T cells were measured to evaluate the immunostimulatory effect. The results showed that chitosan hydrochloride can effectively stabilize the emulsion. The emulsion size is about 600 nm, and the antigen adsorption rate is more than 90%. After immunization, CHE could increase serum antibodies levels and increase IL-4 secretion. Expression of CTL surface activation molecules was also increased to stimulate CTL response further and to increase the CD44+CD62L+ in T cells proportion. CHE as adjuvant can stimulate humoral and cellular immunity more efficiently, and is expected to extend the duration of protection.