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.

Effects of pH and temperature of coprecipitation and thermal treatment on some physicochemical, surface and catalytic properties of nano-sized zinc ferrite

Zinc ferrite nanoparticles were prepared via thermal treatment of zinc-iron mixed hydroxides at 400-600 [degree sign] C. The mixed hydroxides were coprecipitated from their nitrates solutions using NaOH as precipitating agent. The effects of pH and temperature of coprecipitation and calcination temperature on some physicochemical, surface and catalytic properties of the prepared ferrites were studied. The prepared systems were characterized using TG, DTG, DTA, chemical analysis, atomic absorption spectroscopy [AAS], X-ray diffraction [XRD], energy dispersive X-ray [EDX] as well as texture properties based on nitrogen adsorption-desorption isotherms. The results revealed that solid- solid interaction between ZnO and Fe[2]O[3] took place at temperature starting from 400[degree sign] C to produce ZnFe[2]O[3] phase. The surface and catalytic properties of the produced ferrite phase were strongly dependent on coprecipitation conditions of the mixed hydroxides and on their calcinations temperature

Zinc-steel polarity reversal. I. Effect of bicarbonate concentration and temperature

The open circuit potentials of 2 types of zinc and mild steel were followed with time in different NaHCO3 solutions [10-5-10-1 M] at different temperatures [25-80 degree]. No potential reversal of polarity was observed between zinc and mild steel at room temperature. At higher temperatures, passivation of zinc and mild steel would preferentially occur, and potential reversal was manifested, particularly for pure zinc. Impurities, even in minute amounts, enhanced the activation of zinc, as well as sodium hydroxide at adequate concentration even in presence of the bicarbonate. AES survey analysis of the electrode surface gave more insight on the corrosion products

Preparation and structural investigations of titanium substituted Li-Zn ferriets

The mixed ferrites Li0.35 Zn0.30 Tix Fe2.35-x O4 [where x 0.0 to 1.0] were prepared using standard ceramic methods and were sintered at 1150 in static air atmosphere. The formation of ferrite spinel structure was investigated using X-ray diffraction and IR techniques. It was found, that samples with Ti content [x <0.2] have a spinel cubic structure. With increasing titanium content, bulk density and diameter shrinkage were found to decrease, while apparent porosity and grain size increased. Samples with x >0.2 were found to have more than one structural phase

Some electrical and dielectric properties of titanium substituted Li-Zn ferrites

The mixed ferrites used have the stoichiometry Li0.35 Zn0.30 Tix Fe2.35-x O4 [where x=0.0 to 0.25 in steps of 0.05] prepared by a ceramic method and sintered at 1150. The a.c. electrical conductivity, the dielectric constant [epsilon '], and dielectric loss factor [epsilon "] of the prepared specimens were measured within the frequency range 105 to 107 Hz and the temperature range 20 to 60. The electronic conductance mechanism was considered involving electronic exchange between Ti4+ and Fe3+, beside ionic conduction, as influenced by parameters such as temperature and frequency