Efektivitas antibakteri gel chitosan dengan berat molekul berbeda terhadap jumlah koloni bakteri Streptococcus mutans pada permukaan email sekitar braket ortodonti Antibacterial effectiveness of chitosan gel with different molecular weights on the number of Streptococcus mutans colonies in the enamel surface around orthodontic bracket

Pendahuluan: Chitosan merupakan bahan alami, bersifat antibakteri, dan dapat dibentuk menjadi gel sehingga berpotensi sebagai agen profilaksis terhadap Streptococcus mutans, penyebab demineralisasi email. Lesi white spot merupakan salah satu risiko penggunaan alat ortodonti cekat. Berat molekul merupakan salah satu faktor yang memengaruhi efektivitas antibakteri chitosan, namun hubungannya masih memberikan hasil yang inkonsisten. Penelitian ini bertujuan menganalisis perbedaan efektivitas gel chitosan dengan berat molekul berbeda terhadap jumlah koloni bakteri Streptococcus mutans pada permukaan email sekitar braket ortodonti. Metode: Penelitian ini menggunakan metode eksperimen laboratoy dengan menggunakan 24 sampel gigi dengan braket dioles gel chitosan A (50-80 kDa), gel chitosan B (50-150 kDa), gel chitosan C (190-310 kDa), dan gel kontrol klorheksidin diglukonat 0,2% (CHX) masing-masing 6 sampel. Seluruh sampel diinkubasi dalam biakan Streptococcus mutans secara bertahap, 10 μl suspensi dari plak yang terbentuk pada sampel dibiakkan untuk memperoleh koloni pada biakan agar. Data dianalisis dengan uji one-way ANOVA dan Least Significant Difference (LSD). Hasil: Jumlah koloni bakteri Streptococcus mutans setelah aplikasi gel chitosan A, B, C, dan gel klorheksidin diglukonat 0,2% (CHX) didapatkan sebesar 10,05x106 CFU/ml; 9,72x106 CFU/ml; 10,96x106 CFU/ml; dan 4,35x106 CFU/ml sehingga tidak terdapat perbedaan bermakna jumlah koloni bakteri Streptococcus mutans antara ketiga kelompok gel chitosan (p>0,05) dan terdapat perbedaan jumlah koloni bakteri Streptococcus mutans yang bermakna antara ketiga gel chitosan dengan gel kontrol (p<0,05). Simpulan: Efektivitas antibakteri gel chitosan dengan berat molekul berbeda terhadap jumlah koloni bakteri Streptococcus mutans pada permukaan email sekitar braket ortodonti adalah sama besar, namun lebih rendah daripada efektivitas antibakteri gel klorheksidin diglukonat 0,2% pada studi ini.Kata kunci: berat molekul; braket ortodontik; kitosan; email; Streptococcus mutans ABSTRACTIntroduction: Chitosan is a natural ingredient, antibacterial, and can be formed into a gel so that it has the potential as a prophylactic agent against Streptococcus mutans, the cause of enamel demineralization. White spot lesions are one of the risks of using fixed orthodontic appliances. Molecular weight is one factor that affects the antibacterial effectiveness of chitosan, but the relationship still gives inconsistent results. This study aimed to analyze the differences in the effectiveness of chitosan gels with different molecular weights on the number of Streptococcus mutans bacteria colonies on the enamel surface around orthodontic brackets. Methods: This study used an experimental laboratory method using 24 dental samples with brackets smeared with chitosan A gel (50-80 kDa), chitosan B gel (50-150 kDa), chitosan C gel (190-310 kDa), and chlorhexidine control gel. digluconate 0.2% (CHX) each of 6 samples. All samples were incubated in Streptococcus mutans culture in stages, 10 l suspension of the plaque formed on the samples was cultured to obtain colonies on agar cultures. Data were analyzed by one-way ANOVA and Least Significant Difference (LSD). Results: The number of Streptococcus mutans colonies after application of chitosan gel A, B, C, and 0.2% chlorhexidine digluconate (CHX) gel was 10.05x106 CFU/ml; 9.72x106 CFU/ml; 10.96x106 CFU/ml; and 4.35x106 CFU/ml, so that there was no significant difference in the number of Streptococcus mutans colonies between the three chitosan gel groups (p>0.05) and there was a significant difference in the number of Streptococcus mutans bacteria colonies between the three chitosan gels and the control gel (p<0.05). Conclusions: The antibacterial effectiveness of chitosan gel with different molecular weights on the number of Streptococcus mutans bacterial colonies on the enamel surface around orthodontic brackets was simi-lar but lower than the antibacterial effectiveness of 0.2% chlorhexidine digluconate gel.Keywords: molecular weight; orthodontic bracket; chitosan; enamel; Streptococcus mutans

Study of the supramolecularly ordered layered structure of chitosan gel films

Structural and morphological features of chitosan gel films with a radially periodic structure, obtained by neutralizing the salt form of the polymer with sodium hydroxide or triethanolamine, were visualized by scanning electron microscopy. The formation of such supramolecularly ordered layered structures was found to obey diffusion kinetics and the regularities of Liesegang periodic precipitation. The revealed dependence of the morphostructure of our chitosan gel films on the neutralizing reagent used is due to differences in the diffusion rate of inorganic and organic substance, as well as some spatio-temporal features of the mass transfer process.

Polymeric Nanoparticles and Chitosan Gel Loading Ketorolac Tromethamine to Alleviate Pain Associated with Condyloma Acuminata during the Pre- and Post-Ablation

This study describes the preparation and evaluation of two formulations, a hydrogel and a nanostructured system, containing ketorolac tromethamine as an anti-inflammatory agent for the local therapy against the inflammatory process derived from the surgical excision of Condyloma acuminata. Both formulations were physicochemically characterized.In vitrorelease profiles show that the nanoparticles release 92%±2.3 of the total ketorolac tromethamine encapsulated, while the chitosan gel releases 18.6%±0.2. Theex vivo permeation and distribution through human skin were also assayed and was observed how the main amount of ketorolac tromethamine is retained in the epidermis. In vivo studies were accomplished to evaluate the anti-inflammatory efficacy in mice which also involved the histological analysis to confirm thein vivoresults. The nanoparticles present a significantly higher anti-inflammatory efficacy than chitosan gel. The tolerability of developedformulations was assessed by monitoring the biomechanical properties of the skin before and after application of both formulations. No statistical differences in trans-epidermal water loss and skin hydration with respect to the basal values were observed and the formulations exhibited higher anti-inflammatory activity compared to a reference ketotorlac tromethamine solution. Therefore, it can be concluded that both formulations can be proposed as outstanding candidates for offering a local anti-inflammatory therapeutical toolwith potential clinical application.

IMMOBILIZATION OF CELLULASES ON CHITOSAN: APPLICATION FOR SUGARCANE BAGASSE HYDROLYSIS

In this work, a commercial cellulolytic cocktail was immobilized on glutaraldehyde activated chitosan gel. The chitosan concentration in the gel preparation, pH, immobilization time and enzymatic loading were evaluated. Immobilized cellulases showed better hydrolysis performance when an enzyme loading of 134 mg protein/g carrier was used for immobilization at pH 9.0 for 30 minutes. Hydrolysates with a glucose content of 13.43 and 10.35 g/L were obtained when Avicel and pretreated sugarcane bagasse were used as substrate, respectively. Immobilized cellulase lost 60% of its hydrolysis performance after 8 cycles using Avicel, and 75% after 6 cycles for sugarcane bagasse. The hydrolysis performance associated with the reuse of the immobilized cellulases indicates that an improvement in the immobilization of cellulases, coupled with an improvement in the pretreatment of lignocellulosic biomass, will allow the development of a continuous hydrolysis system with the enzyme retained in the reactor.

Estudio Estudio Sobre la Aplicación de Quitosano para la Cura de Lesiones y Heridas de la Piel

En la presente investigación, se evaluó el quitosano aplicado en la piel. Se estudiaron sus bondades terapéuticas cicatrizantes en pacientes con lesiones y ulceraciones en la piel, agudas y crónicas, en un hospital público de la localidad de Puerto Cabello- Estado Carabobo, Venezuela. Se hizo una evaluación continúa tomando en cuenta la gravedad de las lesiones. Se utilizó un material en presentación de apósito (composición acetato de D-glucosamina al 1%) y gel tópico, aplicado a una población de nueve pacientes para evaluar su porcentaje en efectividad, en un número de semanas, de acuerdo a patologías médicas variadas. También se estudió el quitosano (gel, apósito) frente a semanas de tratamiento, llegando a la resolución de las lesiones a un 98.9%, en una duración de 2 a 5 semanas, con 100% de cura de tejido cicatricial y un 98% de resolución completa, aplicando 60% de gel de quitosano y 40% quitosano en apósito. Palabra clave: Quitosano, Lesiones, Heridas de Piel. Abstract In the present investigation, the chitosan applied to the skin was evaluated. Its therapeutic benefits were studied in patients with acute and chronic skin lesions, in a public hospital in the town of Puerto Cabello- Carabobo State, Venezuela. A continuous evaluation was made taking into account the severity of the lesions, a dressing presentation material (1% D-glucosamine acetate composition) and topical gel were used. It was applied to a population of nine (9) patients to evaluate their percentage (%) of effectiveness, in several weeks, according to various medical pathologies, chitosan (gel, dressing) was also studied, compared to weeks of treatment, resolving the lesions 98.9%, in duration from 2 to 5 weeks, with 100% healing of scar tissue and 98% complete resolution, applying 60% chitosan gel and 40% chitosan in dressing. Keywords: Chitosan, Skin Lesions, and Wounds.

3 D printing technology and experimental study of chitosan gel using atomized solidification liquid-assisted extrusion molding

Purpose This paper aims to propose a suitable atomizing solidification chitosan (CS) gel liquid extrusion molding technology for the three dimensional (3D) printing method, and experiments verify the feasibility of this method. Design/methodology/approach This paper mainly uses experimental means, combined with theoretical research. The preparation method, solidification forming method and 3D printing method of CS gel solution were studied. The CS gel printing mechanism and printing error sources are analyzed on the basis of the CS gel ink printing results, printing performance with different ratios of components by constructing a gel print prototype, experiments evaluating the CS gel printing technology and the effects of the process parameters on the scaffold formation. Findings CS printing ink was prepared; the optimal formula was found; the 3 D printing experiment of CS was completed; the optimal printing parameters were obtained; and the reliability of the forming prototype, printing ink and gel printing process was verified, which allowed for the possibility to apply the 3 D printing technology to the manufacturing of a CS gel structure. Originality/value This study can provide theoretical and technical support for the potential application of CS 3 D printed gels in tissue engineering.

Green Chitosan:Thiourea Dioxide Cleaning Gel for Manganese Stains on Granite and Glass Substrates

The cleaning or removal of manganese stains on Cultural Heritage has not been much tested or successful so far. The aim of this article was to assess a new green cleaning gel for Mn-rich black-blue stains on different substrates. The black-blue stains were characterized at optical and chemical level through RGB data, colorimetry, optical microscope, FTIR, XRF and XPS. Mn-stained granite found on historical churches at Vila Real (North of Portugal) and glass jars of Leclanché cells, belonging to the ISEP’s Museum (Portugal) collection, were the ideal case studies to test the efficiency of Chitosan:Thiourea Dioxide (TD) cleaning gel. TD proved to be the best candidate to reduce insoluble manganese oxides, over Hydroxylamine Hydrochloride and Hydroxymethanesulfinic Acid. Cleaning assays performed on stained granite samples collected at a historical quarry and in situ application on stained granite churches showed the complete removal of the stains. Similar results were obtained on stained glass jars. This article presents an innovative, feasible and green Chitosan gel embedded with TD and phosphoric acid, applied to the cleaning of Mn-stained granite and glass substrates.

Swallowing Gel for Patients with Dysphagia: A Novel Application of Chitosan

Dysphagia refers to difficulty swallowing certain foods, liquids, or pills. It is common among the elderly with chronic diseases who need to take drugs for long periods. Therefore, dysphagia might reduce compliance with oral drug administration in the aging population. Many pharmaceutical companies search for new products to serve as swallowing aids. Existing products are expensive and do not suit all geriatric patients. Therefore, this study aimed to develop and investigate pill swallowing aid gels prepared from carboxymethyl cellulose and chitosan. We formulated gels by dissolving different concentrations of carboxymethyl cellulose and low or high molecular weight chitosan in solvents to find appropriate gel rheology properties. We then added several portions of glycerin as the glidant of the formulation. We found that the optimized gel formulation was 6.25% (w/w) chitosan with a molecular weight of 80–120 kDa dissolved in 1.2% acetic acid and 4% (w/w) glycerin. The developed pill swallowing gel’s rheology was pseudoplastic with a viscosity of 73.74 ± 3.20 Pa⸱s. The developed chitosan gel had enhanced flow ability; it allowed the pill to cross a 300 mm tube within 6 s, while the reference product took 3 s. Even though the reference product could carry the pill in the tube faster, the chitosan gel better covered the pill, making it more convenient to use. Finally, using a theophylline tablet as a model tablet dosage form, we assessed the gel’s effect on drug disintegration and dissolution. The chitosan gel delayed the tablet disintegration time by about 3–7 min and slightly affected the theophylline dissolution rate. Lastly, all gels were physically stable after a month of storage in the stress condition. These results show the feasibility of manufacturing a chitosan gel usable as a pill swallowing gel for patients with dysphagia.