Green isolation of cellulosic materials from recycled pulp and paper sludge: a Box-Behnken design optimization.

Cellulose was isolated from recycled pulp and paper sludge and used to synthesize cellulose nanocrystals. Response surface methodology and Box-Behnken design model were used to predict, improve, and optimize the cellulose isolation process. The optimal conditions were a reaction temperature of 87.5 °C, 180 min with 4% sodium hydroxide. SEM and TEM results revealed that the isolated cellulose had long rod-like structures of different dimensions than CNCs with short rod-like structures. The crystallinity index from XRD significantly increased from 41.33%, 63.7%, and 75.6% for Kimberly mill pulp sludge (KMRPPS), chemically purified cellulose and cellulose nanocrystals, respectively. The TGA/DTG analysis showed that the isolated cellulosic materials possessed higher thermal stability. FTIR analysis suggested that the chemical structures of cellulose and CNCs were modified by chemical treatment. The cellulose surface was highly hydrophilic compared to the CNCs based on the high water holding capacity of 65.31 ± 0.98% and 83.14 ± 1.22%, respectively. The synthesized cellulosic materials portrayed excellent properties for high-end industrial applications like biomedical engineering, advanced materials, nanotechnology, sustainable packaging, personal care products, environmental remediation, additive manufacturing, etc.

Development, characterization and antimalarial efficacy of dihydroartemisinin loaded solid lipid nanoparticles.

Effective use of dihydroartemisinin (DHA) is limited by poor water-solubility, poor pharmacokinetic profile and unsatisfactory clinical outcome especially in monotherapy. To reduce such limitations, we reformulated DHA into solid lipid nanoparticles (SLNs) as a nanomedicine drug delivery system. DHA-SLNs were characterized for physical parameters and evaluated for in vitro and in vivo antimalarial efficacy. DHA-SLNs showed desirable particle characteristics including particle size (240.7 nm), particle surface charge (+17.0 mV), drug loadings (13.9 wt %), encapsulation efficacy (62.3%), polydispersity index (0.16) and a spherical appearance. Storage stability up to 90 days and sustained release of drug over 20 h was achieved. Enhanced in vitro (IC50 0.25 ng/ml) and in vivo (97.24% chemosuppression at 2mg/kg/day) antimalarial activity was observed. Enhancement in efficacy was 24% when compared to free DHA. These encouraging results show potential of using the described formulation for DHA drug delivery for clinical application. FROM THE CLINICAL EDITOR: Malaria still poses a significant problem worldwide. One of the current drugs, artemisinin has been shown to be effective, but has poor water-solubility. The authors here described their formulation of making dihydroartemisinin (DHA) into solid lipid nanoparticles, with subsequent enhancement in efficacy. These results would have massive potential in the clinical setting.

Excessive Copper(II) and Zinc(II) Levels in Drinkable Water Sources in Areas Along the Lake Victoria Shorelines in Siaya County, Kenya.

Copper(II) and zinc(II) levels in drinkable water sources in the alluvium areas of the Lake Victoria Basin in Siaya County of Kenya were evaluated to assess the risk posed to resident communities by hydrogeological accumulation of toxic residues in the sedimentary regions of the lake basin. The levels of the metals in water were analyzed by atomic absorption spectroscopy. Metal concentrations ranged from 0.11 to 4.29 mg/L for Cu(II) and 0.03 to 1.62 mg/L for Zn(II), which were both higher than those normally recorded in natural waters. The Cu(II) levels also exceeded WHO guidelines for drinking water in 27% of the samples. The highest prevalence of excessive Cu(II) was found among dams and open pans (38%), piped water (33%) and spring water (25%). It was estimated that 18.2% of the resident communities in the current study area are exposed to potentially toxic levels of Cu(II) through their drinking water.