Potential Alendronate Sodium drug carrier by preparation and characterization of sodium alginate cross-linked Montmorillonite

Abstract In drug therapy, it is important to provide therapeutic levels of drug to the site of action and maintain them during the treatment. This work describes the in vitro release of alendronate from sodium alginate cross-linked Montmorillonite (MMT) composite beads. Effect of crosslinking cation, concentration of montmorillonite and media on encapsulation efficiencies, and release profiles of alendronate were studied. Beads were characterized using equilibrium swelling ability study, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Energy-dispersive x-ray spectroscopy (EDX) and scanning electron microscopy (SEM). Results indicate that addition of montmorillonite increases the encapsulation efficiencies and slows down the release rates significantly.

The osteogenesis of Ginsenoside Rb1 incorporated silk/micro-nano hydroxyapatite/sodium alginate composite scaffolds for calvarial defect / 国际口腔科学杂志·英文版

Ginsenoside Rb1, the effective constituent of ginseng, has been demonstrated to play favorable roles in improving the immunity system. However, there is little study on the osteogenesis and angiogenesis effect of Ginsenoside Rb1. Moreover, how to establish a delivery system of Ginsenoside Rb1 and its repairment ability in bone defect remains elusive. In this study, the role of Ginsenoside Rb1 in cell viability, proliferation, apoptosis, osteogenic genes expression, ALP activity of rat BMSCs were evaluated firstly. Then, micro-nano HAp granules combined with silk were prepared to establish a delivery system of Ginsenoside Rb1, and the osteogenic and angiogenic effect of Ginsenoside Rb1 loaded on micro-nano HAp/silk in rat calvarial defect models were assessed by sequential fluorescence labeling, and histology analysis, respectively. It revealed that Ginsenoside Rb1 could maintain cell viability, significantly increased ALP activity, osteogenic and angiogenic genes expression. Meanwhile, micro-nano HAp granules combined with silk were fabricated smoothly and were a delivery carrier for Ginsenoside Rb1. Significantly, Ginsenoside Rb1 loaded on micro-nano HAp/silk could facilitate osteogenesis and angiogenesis. All the outcomes hint that Ginsenoside Rb1 could reinforce the osteogenesis differentiation and angiogenesis factor's expression of BMSCs. Moreover, micro-nano HAp combined with silk could act as a carrier for Ginsenoside Rb1 to repair bone defect.

Evaluation of wound healing effect of alginate film containing Aloe vera gel and cross-linked with zinc chloride

Abstract Purpose To develop a new wound dressing composed of alginate and Aloe vera gel and cross-linked with zinc ions. Methods The aloe-alginate film was characterized using scanning electron microscopy (SEM), swelling profile, mechanical properties, polysaccharide content and X-ray diffraction (XRD). Thirty Wistar rats were divided in two groups a) treated with aloe-alginate film and b) control (treated with sterile gauze). Wound contraction measurements and hystological analysis were performed on 7th, 14th and 21st days after wound surgery. Results The aloe-alginate film presented adequated mechanical resistance and malleability for application as wound dressing. There was no statistical difference in wound contraction between two groups. Histological assay demonstrated that aloe-alginate film presented anti-inflammatory activity, stimulated angiogenesis on proliferative phase and a more significant increased in collagen type I fibers and decreased type III fibers which promoted a mature scar formation when compared to control. Conclusions The aloe-alginate film showed adequate physicochemical characteristics for wound dressing applications. The in vivo assay demonstrated that aloe-alginate film enhanced the healing process of incisional skin wounds.

Alveolar bone repair with strontium- containing nanostructured carbonated hydroxyapatite

ABSTRACT Objective: This study aimed to evaluate bone repair in rat dental sockets after implanting nanostructured carbonated hydroxyapatite/sodium alginate (CHA) and nanostructured carbonated hydroxyapatite/sodium alginate containing 5% strontium microspheres (SrCHA) as bone substitute materials. Methods: Twenty male Wistar rats were randomly divided into two experimental groups: CHA and SrCHA (n=5/period/group). After one and 6 weeks of extraction of the right maxillary central incisor and biomaterial implantation, 5 μm bone blocks were obtained for histomorphometric evaluation. The parameters evaluated were remaining biomaterial, loose connective tissue and newly formed bone in a standard area. Statistical analysis was performed by Mann-Withney and and Wilcoxon tests at 95% level of significance. Results: The histomorphometric results showed that the microspheres showed similar fragmentation and bio-absorbation (p>0.05). We observed the formation of new bones in both groups during the same experimental periods; however, the new bone formation differed significantly between the weeks 1 and 6 (p=0.0039) in both groups. Conclusion: The CHA and SrCHA biomaterials were biocompatible, osteoconductive and bioabsorbable, indicating their great potential for clinical use as bone substitutes.

Cytocompatibility and biocompatibility of nanostructured carbonated hydroxyapatite spheres for bone repair

ABSTRACT Objective The aim of this study was to investigate the in vitro and in vivo biological responses to nanostructured carbonated hydroxyapatite/calcium alginate (CHA) microspheres used for alveolar bone repair, compared to sintered hydroxyapatite (HA). Material and Methods The maxillary central incisors of 45 Wistar rats were extracted, and the dental sockets were filled with HA, CHA, and blood clot (control group) (n=5/period/group). After 7, 21 and 42 days, the samples of bone with the biomaterials were obtained for histological and histomorphometric analysis, and the plasma levels of RANKL and OPG were determined via immunoassay. Statistical analysis was performed by Two-Way ANOVA with post-hoc Tukey test at 95% level of significance. Results The CHA and HA microspheres were cytocompatible with both human and murine cells on an in vitro assay. Histological analysis showed the time-dependent increase of newly formed bone in control group characterized by an intense osteoblast activity. In HA and CHA groups, the presence of a slight granulation reaction around the spheres was observed after seven days, which was reduced by the 42nd day. A considerable amount of newly formed bone was observed surrounding the CHA spheres and the biomaterials particles at 42-day time point compared with HA. Histomorphometric analysis showed a significant increase of newly formed bone in CHA group compared with HA after 21 and 42 days from surgery, moreover, CHA showed almost 2-fold greater biosorption than HA at 42 days (two-way ANOVA, p<0.05) indicating greater biosorption. An increase in the RANKL/OPG ratio was observed in the CHA group on the 7th day. Conclusion CHA spheres were osteoconductive and presented earlier biosorption, inducing early increases in the levels of proteins involved in resorption.

Optimization of Gabapentin Release and Targeting Absorption, Through Incorporation into Alginate Beads.

Aims: 1) To study the effect of some formulation variables on drug load, encapsulation efficiency, swelling ratio, mucoadhesion and drug release. 2) Optimize the mucoadhesion capabilities for targeting drug absorption and release-controlling capabilities of alginate beads. Methodology: Alginate beads were prepared by dripping sodium alginate gel into calcium chloride solution and then dried overnight at ambient temperature. The effects of alginate concentration, cross linker concentration, cross linking time, volume of cross linking solution and drug/polymer ratio on drug load, encapsulation efficiency, swelling ratio, mucoadhesion and drug release were investigated. Formulae containing sodium lauryl sulfate (SLS), gabapentin-ethylcellulose solid dispersion, mixture of free drug and solid dispersion were prepared for modifying the drug release rate. Results: Mucoadhesion of alginate beads was shown to be decreased upon adding SLS (30% after 8 hrs). Drug release was so fast (92.46% after 2 hrs). The incorporation of solid dispersion has led to well accepted mucoadhesion (74.44% after 8 hrs) as well as release properties (93.35% after 10 hrs) Beads containing mixtures of drug and ethylcellulose-drug solid dispersion showed acceptable mucoadhesion (74.44% after 8 hrs) and control of gabapentin release (93.35% after 10 hrs). Statistical analysis of variance between groups was performed using the one-way layout ANOVA with duplication. Significant differences in mean values were evaluated by Student's unpaired t test (P < 0.05). Conclusion: A finally optimized formula was suggested by incorporating a combination of solid dispersion and free gabapentin in alginate system to achieve burst release of gabapentin and hence fast effect (33.417% was released during the first 30 minutes in fasting-simulated conditions) and controlled release (91.217% after 6 hrs).

Formulation and evaluation of cosmeceutical preparations loaded with triclosan beads

The present study aims at sustainment of the antibacterial action of Triclosan when applied to the scalp or the skin by Preparation of Triclosan-alginate beads in different concentration of sodium alginate beads, different ratios of drug-sodium alginate and with different concentrations of calcium chloride. The prepared beads were subjected to the drug entrapment efficiency. Incorporation of beads[4: 1 of drug: sodium alginate in 0.5% w/v] in cosmoceuticals preparations viz., cold cream, carbopol 934 gel, sodium carboxymethyl cellulose gel and Texapon N70 shampoo were subjected to determination of pH of different cosmoceuticals preparations before and after incorporation of beads, release studies of triclosan beads with and without drug beads, then Invitro release studies of cosmoceuticals preparation containing 1% in beads and 1% of free triclosan and 2% beads was determined using Franz-type diffusion cell in phosphate buffer of pH 5.8. Rheology of triclosan beads with and without free triclosan in pharmaceutical preparations were done in comparison with plain ones. The results reveled that, the highest rate and extent of Triclosan-l%in beads and 1%of free drug was given by CMC gel base which exhibited plastic thixotropic flow curve, the drug lowest release was exhibited by Texapon N70 shampoo .Pertaining to the release of Triclosan 2% beads, it was evident that the highest release was from CMC gel base which exhibited plastic thixotropic flow curve, while the least release rate was from Texapon N70 shampoo exhibited plastic thixotropic flow curve with smaller extent

In vitro antimicrobial activity of irreversible hydrocolloid impressions against 12 oral microorganisms

This study evaluated in vitro the antimicrobial activity of irreversible hydrocolloids (one containing an antimicrobial agent) prepared with water or with a 0.2 percent chlorhexidine digluconate solution against 12 strains of the oral microbiota. Twenty specimens (0.5 x 1.0 cm) for each group (1. Jeltrate mixed with water; 2. Jeltrate mixed with 0.2 percent chlorhexidine digluconate solution; 3. Greengel mixed with water; 4. Greengel mixed with 0.2 percent chlorhexidine digluconate solution) were prepared under sterile conditions and placed in culture media inoculated with the indicator strains. After incubation in aerobiosis or microaerophilia, inhibition of the microbial growth was measured and the results were interpreted. The normal adherence curve revealed a non-normal distribution of the data, so the non-parametric Friedman Test was performed (p < 0.05). The antimicrobial activity of the groups was classified in the following order: 1, 3, 4, and 2. The results suggest that the method of preparing irreversible hydrocolloids with a 0.2 percent digluconate chlorhexidine solution is more effective than the incorporation of an antimicrobial agent in the powder to reduce cross-contamination caused by impressions.

Este trabalho avaliou in vitro a atividade antimicrobiana de alginatos (um deles contendo agente antimicrobiano) manipulados com água ou solução de digluconato de clorexidina a 0,2 por cento contra 12 cepas da microbiota oral. Vinte espécimes (0,5 x 1,0 cm) para cada grupo (1. Jeltrate manipulado com água, 2. Jeltrate manipulado com solução de digluconato de clorexidina a 0,2 por cento; 3. Greengel manipulado com água; 4. Greengel manipulado com solução de digluconato de clorexidina a 0,2 por cento) foram confeccionados sob condições estéreis e semeados em meios de cultura inoculados com as cepas indicadoras. Após incubação em aerobiose ou microaerofilia, a inibição do crescimento microbiano foi medida e os resultados foram interpretados. A curva normal de aderência revelou uma distribuição não-normal dos dados, então o teste não paramétrico de Friedman (p < 0,05) foi realizado. A atividade antimicrobiana dos grupos foi classificada na seguinte ordem crescente: 1, 3, 4 e 2. Os resultados sugerem que a manipulação de alginatos com solução de digluconato de clorexidina a 0,2 por cento é um método efetivo para reduzir a contaminação-cruzada causada pelos moldes, mais que a incorporação do agente antimicrobiano no pó.

Determination of calcium by atomic absorption spectrophometry applied to the preparation of alginate: chitosan complexes

Polysaccharides, as alginate and chitosan, have been used to obtain modified release dosage forms. Alginate, due to its porperty of building gels during complex formation with calcium ions, allows the building of capsules containing a core constituted by calcium alginate. This work had for objective to determine the appropriate calcium concentration for the preparation of alginate-chitosan capsules, by means of calcium quantification using atomic absorption spectrophotometry. The methodology of calcium quantification was validated through analysis of the limit of detection, precision, accuracy and recovery of the method. The capsules, containing or not the drug, were prepared by the complex coacervation/ionotropic gelification method. Calcium was quantified after samples mineralization and dilution in lantanium solution. The results showed that the amount of calcium incorporated into the capsules depends on the amount of calcium added to the medium, and this ratio increases until the concentration of 1,5% of initial calcium chloride and above this concentration there is a decrease in the proportion of calcium bonded. It was observed that the proportion of calcium that links to the polymer is inversely proportional to the amount of calcium added. The calcium amount incorporated depends on the concentration of the polymeeric dispersions used as well as on the between the two polymers

Estudo da abrasividade de formulaçöes básicas de dentifrícios / Study of abrasivity of dentifrices basic formulations

O estudo da abrasividade de formulaçöes básicas de dentifrícios envolvendo vários tipos de espessantes e abrasivos, demonstrou uma dependência da interaçäo desses componentes, fundamentais nesse tipo de produto. As diferentes associaçöes estudadas tornaram possível a estruturaçäo de índices de abrasividade específicos a cada uma delas.

The effect of alginic matrix on cadmium uptake by an immobilized green microalgae

Este trabalho descreve alguns estudos de absorçäo de cádmio por células de Chlorella homosphaera livres e imobilizadas em alginato, bem como a absorçäo devida à matriz polimérica isenta de células em soluçöes de cádmio na faixa de concentraçöes de 8,7 a 45,0 mg/l. A captaçäo do metal foi mais efetiva com o uso de células livres até a concentraçäo de 26,8 mg/l do metal. Os resultados obtidos com emprego do alginato e células aprisionadas em alginato estäo provavelmente associados à porosidade da matriz e à densidade celular dentro das partículas de alginato