CONTROLLED RELEASE OF FERTILIZER MICROCAPSULES USING ETHYLENE VINYL ACETATE POLYMER TO ENHANCE MICRONUTRIENT AND WATER USE EFFICIENCY

There have as yet been no detailed studies of micronutrient release from polymer coated fertilizers (PCFs). In this research, slow release microcapsules containing iron fertilizer was made and its release pattern evaluated. Three polymers ethyl cellulose (EC), glycerol mono stearate (GMS) and Compritol 888 ATO, were mixed with avicel and lactose and the microcaopsules were made by extrusion/spheronization method. The dissolution test carried out to determine the Fe release rate versus time. The results showed that, microcaopsules containing Compritol 888 ATO, released iron ions slower than that of EC and GMS. The release rate reached 85% after 7 days. In order to reduce the release rate, these microcaopsules were coated with ethylene vinyl acetate (EVA) polymer by dip coating method. It is concluded that the combination of matrix type formulation and the coating with EVA polymer caused a significant decrease in the release rate of iron.     

Effect of heat stress on the growth,root sugars,acid invertase and protein profile of pepper seedlings following transplanting

The development of pepper transplants is sensitive to the prevailing temperature in the field. High temperatures immediately after transplanting pepper seedlings delay their development in the field. During nine days of post-transplanting heat stress (30/25°C or 35/25°C, day/night temperature regimes), root and shoot growth were inhibited compared to the control transplants (25/18°C) with a significant decline in total protein and soluble acid invertase activity in the roots of the heat stressed plants. Acid invertase activity was less sensitive to the heat stress in the leaves than in the roots. A significant reduction in the root invertase activity occurred as early as two days after the beginning of the stress. Transplanting caused a 72% inhibition in the carbon allocation to the roots, compared with the non-transplanted seedlings. Exposure to heat after transplanting did not further reduce carbon allocation to the roots. The protein profile on SDS-PAGE from leaves shows that during the heat stress, some heat related proteins were synthesized concomitant with the reduction in the synthesis of constitutive proteins. In the roots, the synthesis of heat related proteins was barely detectable with no visible changes in the protein profile. The results suggest that roots are more sensitive to heat stress than leaves, possibly because they are less able to synthesize heat related proteins. The causal relationship between protein synthesis during heat stress and the performance of the transplants is not well understood.     

Montelukast incorporated poly(methyl vinyl ether-co-maleic acid)/poly(lactic-co-glycolic acid) electrospun nanofibers for wound dressing

The aim of the present study was to prepare nanofibers loaded with montelukast, a cysteinyl leukotrienes (CysLTs) inhibitor, with anti-inflammatory properties effective on wound healing. Polymeric nanofibers containing montelukast were spun by electrospinning method using different ratios of the blend of two biodegradable polymers of poly(methyl vinyl etherco-maleic acid) (PMVEMA) and poly(lactic-co-glycolic acid) (PLGA) at the total polymer concentration of 37 %, the distance of the needle to rotating screen of 19 cm, the voltage of 12 Kv and the rate of injection of 0.2 ml/h. The ratio of two polymers in the blend and the concentration of montelukast were optimized based on the diameter of the nanofibers, drug loading percent and release efficiency by a full factorial design. The morphology, diameter and diameter distribution of the nanofibers were studied by scanning electron microscopy (SEM). Drug loading percent in the nanofibers was determined by extracting the loaded drug from a specific surface of the nanofibers which was subsequently analyzed spectrophotometrically. The drug release rate from the nanofibers was studied in phosphate buffer solution (pH 7.4) containing 0.5 % Tween 20 at predetermined time intervals until 10 days. The cytotoxicity of the designed nanofibers was evaluated on mouse fibroblast cells using trypan blue method, their platelet adherence property was quantified by measuring the lactate dehydrogenase (LDH) activity and confirmed by SEM micrographs. The optimized ratio of PLGA/PMVEMA was 3:1 with the total concentration of polymers as 37 % loaded with 30 % of montelukast produced nanofibers with a diameter of 157.6 nm, drug loading percent of 43.7 % and release efficiency of 75 % after 10 days. The cell viability was similar in nanofibers and the negative control group. The platelets adhesion to the nanofibers was more than the negative control group (p<0.05).     

Alteration in the Expression of Proteins in Unexplained Recurrent Pregnancy Loss Compared with in the Normal Placenta

The placenta is a unique pregnancy-related tissue and plays a key role in occurrence of unexplained recurrent pregnancy loss (URPL). Abnormal placentation might play a key role in occurrence of URPL. Therefore, the purpose of this study was to compare the human placental proteome between URPL placentas and normal placental matched for gestational week. Total placental proteins were extracted, and the two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) technique was used for separation of the placental proteomes. Protein spots differentially expressed between URPL and normal placentas were selected and identified by the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF/TOF) technique after being digested in the gel. Moreover, quantitative real-time PCR and Western blot techniques were used to confirm the differential expression mass results for some differentially expressed proteins. The results indicated that at least 19 protein spots were differentially expressed between URPL and normal placentas (P < 0.05), and twelve of them were successfully identified. While only two proteins were downregulated (calumenin and enolase 1), the remaining ten spots (actin gamma 1 propeptide, cathepsin D prepropeptide, heat shock protein gp96, tubulin beta, tubulin alpha 1, glutathione S-transferase, vitamin D binding protein, prohibitin, actin beta, apolipoprotein A-I) showed increased expression in URPL cases in comparison with normal placentas. Real-time PCR also confirmed the downregulation of calumenin and upregulation of prohibitin and apolipoprotein A-I at the mRNA levels. In conclusion, the results of the present study showed that alteration in the expression of proteins involved in proliferation and migration of endothelial cells as well as control of coagulation by these cells might play an important role in the pathogenesis of URPL.