Biomass of the macrophyte remedies and detoxifies Cd(II) and Pb(II) in aqueous solution.

Aquatic plants are considered to be important remedial agents in aquatic environments contaminated by metals. The Salvinia biloba macrophyte was evaluated in relation to its removal kinetics, adsorption capacity, and toxicology, aiming at its application in the removal of Cd+2 and Pb+2 ions from aqueous solutions. A batch-type system was used, in which the plants were cultivated in microcosms containing nutritive solution and metallic ions, stored in a controlled environment (pH, temperature, and luminosity). The removal kinetics consisted in the analysis of efficiency, varying the concentrations of the metals, and time of cultivation of plants in solution. To describe the process, adsorption isotherms were constructed with the equilibrium data, which were later adjusted to Langmuir and Freundlich models. The toxicological trial was performed by sub-acute exposure test of Caenorhabditis elegans nematode to phytoremediated solutions. The results highlight the remedial effect of the plant in solutions contaminated with both metals. The kinetic study demonstrated that the plant responds differently to metals, and physical-chemical and biological processes can be attributed to the removal of metals from the solution by the plant. The equilibrium time obtained was 48 h for both metals, and the adsorption capacity was higher for Cd2+. The toxicological evaluation indicates that there was a reduction in toxicity after the remediation of the solutions by S. biloba, for all times and concentrations evaluated. Salvinia biloba was efficient for the removal of Cd2+ and Pb2+ metals from aqueous solution. The plant is a low-cost metal biosorbent and can be considered promising for phytoremediation strategies in liquid effluents and water bodies.

Assessment of the Cu(II) and Pb(II) removal efficiency of aqueous solutions by the dry biomass Aguapé: kinetics of adsorption.

Plant-based materials are promising adsorbents for treating liquid effluents. This study describes the kinetic and equilibrium parameters that best represent the copper(II) and lead(II) removal process by Eichhornia crassipes (Aguapé) dry biomass from aqueous solution, using a batch adsorption system. The plants were washed, dried, and reduced to small particles. The adsorption kinetics were assessed by varying the metal concentrations in 5, 10, and 20 mg L-1 and a control treatment (without metals) with a mixture contact time of between 5 and 720 min. Equilibrium data were fitted to the Langmuir and Freundlich models. Kinetic assay revealed fast adsorption: kinetic equilibrium was attained within 2 h with a removal efficiency of ~ 60%. The results demonstrated a fast recovery cycle of metals using the biosorbent. The biomass of E. crassipes is low cost with potential for use as a biosorbent to remove metals from solutions.

A Prospective, Descriptive Study to Assess the Clinical Benefits of Using Calendula officinalis Hydroglycolic Extract for the Topical Treatment of Diabetic Foot Ulcers.

Diabetic foot ulcers (DFUs) have a significant impact on patient quality of life. A prospective, descriptive pilot study was conducted between May 2012 and December 2013 through the dermatology outpatient unit in a Brazilian hospital to evaluate the clinical benefits of using Calendula officinalis hydroglycolic extract in the treatment of DFUs. Patients diagnosed with a stable neuropathic ulcer of >3 months' duration; ranging in size from 0.5-40 cm(2); without osteomyelitis, gangrene, bone exposure, cancer, or deep tissue infection; ages 18-90 years; with adequate glycemic control and no history of an allergy to C. officinalis were enrolled. Patients provided demographic and diabetes-related information and were evaluated biweekly for 30 weeks or until healing (ie, full epithelialization with no wound drainage). DFUs were measured and clinically examined for microbiological flora and presence of odor, tissue type (eg, granulation, fibrin sloth, necrosis), exudate, and retraction rate using planimetry images. Patients' blood tests and neuropathic pain assessment (the latter by clinician-directed questionnaire) were performed at baseline and the end of treatment; pain also was assessed during dressing changes using a 10-point rating scale. Patients' ulcers were treated twice daily with C. officinalis hydroglycolic extract spray solution and covered with saline-moistened, sterile, nonadherent gauze and bandages followed by foot offloading with adequate protective footwear. Patients received their first treatment in the clinic then performed care at home. From a potential population of 109 patients, 25 did not meet the inclusion criteria. Of the remaining 84 participants enrolled, 43 withdrew before study completion; cited reasons included lost to follow-up (16), medical judgment (2), failure to attend >3 scheduled visits (17), protocol violation (5), and death (3). Forty-one (41) - 17 women, average age 62 years (range 44-82 years), average glycemic level 153 mg/dL (range 82-395 mg/dL), most (34) with Wagner type 1 ulcers--completed the study. The proportions of patients who achieved complete wound closure after 11, 20, and 30 weeks of treatment was 54%, 68%, and 78%, respectively; mean healing time was 15.5 ± 6.7 weeks. When individual weekly healing rates (the percentage reduction in wound area per week) were corrected for variability in initial DFU area, the values were nearly 6-fold higher for complete wound closure (7.8% ± 3.6%) than for incomplete wound closure (1.4% ± 0.7%) (Student t-test; P = 0.001). After 30 weeks of treatment, the number of colonized wounds decreased from 29 at baseline to 5, and the number of odorous wounds decreased from 19 to 1. Ulcer bed planimetry data showed a significant reduction in the amount of exudate, fibrin slough, and necrotic tissue after the treatment with C. officinalis hydroglycolic extract (χ(2) test; P = 0.001). No adverse events were observed during treatment. The study findings suggest C. officinalis extract is safe and has a beneficial effect on DFU healing. Randomized, controlled studies using C. officinalis hydroglycolic extract are warranted to confirm its safety and establish its clinical efficacy and effectiveness for the topical treatment of DFUs.