Reaction Pattern and Mechanistic Aspects of Iodine and Iodine-Based Reagents in Selenylation of Aliphatic, Aromatic, and (Hetero)Cyclic Systems.

Organoselenium compounds have been the subject of extensive research since the discovery of the biologically active compound ebselen. Ebselen has recently been found to show activity against the main protease of the virus responsible for COVID-19. Other organoselenium compounds are also well-known for their diverse biological activities, with such compounds exhibiting interesting physical properties relevant to the fields of electronics, materials, and polymer chemistry. In addition, the incorporation of selenium into various organic molecules has garnered significant attention due to the potential of selenium to enhance the biological activity of these molecules, particularly in conjunction with bioactive heterocycles. Iodine and iodine-based reagents play a prominent role in the synthesis of organoselenium compounds, being valued for their cost-effectiveness, non-toxicity, and ease of handling. These reagents efficiently selenylate a broad range of organic substrates, encompassing alkenes, alkynes, and cyclic, aromatic, and heterocyclic molecules. They serve as catalysts, additives, inducers, and oxidizing agents, facilitating the introduction of different functional groups at alternate positions in the molecules, thereby allowing for regioselective and stereoselective approaches. Specific iodine reagents and their combinations can be tailored to follow the desired reaction pathways. Here, we present a comprehensive review of the progress in the selenylation of organic molecules using iodine reagents over the past decade, with a focus on reaction patterns, solvent effects, heating, microwave, and ultrasonic conditions. Detailed discussions on mechanistic aspects, such as electrophilic, nucleophilic, radical, electrochemical, and ring expansion reactions via selenylation, multiselenylation, and difunctionalization, are included. The review also highlights the formation of various cyclic, heterocyclic, and heteroarenes resulting from the in situ generation of selenium intermediates, encompassing cyclic ketones, cyclic ethers, cyclic lactones, selenophenes, chromones, pyrazolines, pyrrolidines, piperidines, indolines, oxazolines, isooxazolines, lactones, dihydrofurans, and isoxazolidines. To enhance the reader's interest, the review is structured into different sections covering the selenylation of aliphatic sp2/sp carbon and cyclic sp2 carbon, and then is further subdivided into various heterocyclic molecules.

Intermolecular C-H Aminocyanation of Indoles via Copper-iodine Cocatalyzed Tandem C-N/C-C Bond Formation.

An efficient copper-iodine cocatalyzed intermolecular C-H aminocyanation of indoles with a broad substrate scope has been developed for the first time. This method enables highly step-economic access to 2-amino-3-cyanoindoles in moderate to good yields and provides a complementary strategy for the regioselective difunctionalization of carbon═carbon double bonds of interest in organic synthesis and related areas. Mechanistic studies suggest that these transformations are initiated by iodine-mediated C2-H amination with azoles, followed by copper-catalyzed C3-H cyanation with ethyl cyanoformate.

Climate changes modulated the history of Arctic iodine during the Last Glacial Cycle.

Iodine has a significant impact on promoting the formation of new ultrafine aerosol particles and accelerating tropospheric ozone loss, thereby affecting radiative forcing and climate. Therefore, understanding the long-term natural evolution of iodine, and its coupling with climate variability, is key to adequately assess its effect on climate on centennial to millennial timescales. Here, using two Greenland ice cores (NEEM and RECAP), we report the Arctic iodine variability during the last 127,000 years. We find the highest and lowest iodine levels recorded during interglacial and glacial periods, respectively, modulated by ocean bioproductivity and sea ice dynamics. Our sub-decadal resolution measurements reveal that high frequency iodine emission variability occurred in pace with Dansgaard/Oeschger events, highlighting the rapid Arctic ocean-ice-atmosphere iodine exchange response to abrupt climate changes. Finally, we discuss if iodine levels during past warmer-than-present climate phases can serve as analogues of future scenarios under an expected ice-free Arctic Ocean. We argue that the combination of natural biogenic ocean iodine release (boosted by ongoing Arctic warming and sea ice retreat) and anthropogenic ozone-induced iodine emissions may lead to a near future scenario with the highest iodine levels of the last 127,000 years.

Comparative Protective Effect of Nigella sativa Oil and Vitis vinifera Seed Oil in an Experimental Model of Isoproterenol-Induced Acute Myocardial Ischemia in Rats.

The study's aim was to characterize the composition of Nigella sativa seed (NSO) and grape seed (GSO) oils, and to evaluate their cardioprotective and anti-inflammatory effect on isoproterenol (ISO)-induced ischemia in rats. Materials and Methods: NSO and GSO supplements were physicochemically characterized. Liquid chromatography-mass spectrometry (HPLC-MS), Fourier-transform infrared spectroscopy (FTIR), and gas chromatography-mass spectrometry (GC-MS) analyses were used to determine the phytochemical composition in the oils. Total polyphenol content (TPC) and in vitro antioxidant activity were also determined. Pretreatment with 4 mL/kg/day NSO or GSO was administered to rats for 14 days. The experimental ischemia was induced by a single administration of ISO 45 mg/kg after 14 days. An electrocardiogram (ECG) was performed initially and 24 h after ISO. Biological evaluation was done at the end of experiment. Results: The HPLC-MS, GC-MS, and FTIR analyses showed that both NSO and GSO are important sources of bioactive compounds, especially catechin and phenolic acids in GSO, while NSO was enriched in flavonoids and thymol derivatives. Pretreatment with GSO and NSO significantly reduced ventricular conduction, prevented the cardiotoxic effect of ISO in ventricular myocardium, and reduced the level of proinflammatory cytokines and CK-Mb. Conclusion: Both NSO and GSO were shown to have an anti-inflammatory and cardioprotective effect in ISO-induced ischemia.

Potato starch modified by Streptococcus thermophilus GtfB enzyme has low viscoelastic and slowly digestible properties.

Potato starch with high viscosity and digestibility cannot be added into some foods. To address this issue, a novel starch-acting enzyme 4,6-α-glucosyltransferase from Streptococcus thermophilus (StGtfB) was used. StGtfB decreased the iodine affinity and the molecular weight, but increased the degree of branching of starch at a mode quite different from glycogen 1,4-α-glucan branching enzyme (GBE). StGtfB at 5 U/g substrate mainly introduced DP 1-7 into amylose (AMY) or DP 1-12 branches into amylopectin (AMP), and increased the ratio of short- to long-branches from 0.32 to 2.22 or from 0.41 to 2.50. The DP 3 branch chain was the most abundant in both StGtfB-modified AMY and StGtfB-modified AMP. The DP < 6 branch chain contents in StGtfB-modified AMY were 42.68%, much higher than those of GBE-modified AMY. StGtfB significantly decreased viscoelasticity but still kept pseudoplasticity of starch. The modifications also slowed down the glucose generation rate of products at the mammalian mucosal α-glucosidase level. The slowly digestible fraction in potato starch increased from 34.29% to 53.22% using StGtfB of 5 U/g starch. This low viscoelastic and slowly digestible potato starch had great potential with respect to low and stable postprandial blood glucose.

Preparation of cross-linked enzyme aggregates of lipase from Aspergillus niger: process optimization, characterization, stability, and application for epoxidation of lemongrass oil.

Cross-linked enzyme aggregates (CLEAs) of lipase were prepared after fractional precipitation with 40-50% ammonium sulfate and then cross-linking with glutaraldehyde. The process variables for the preparation of lipase-CLEAs such as glutaraldehyde concentration, cross-linking period, and initial pH of medium were optimized. The optimized conditions for the preparation of lipase-CLEAs were 25 mM/80 min/pH 7.0, and 31.62 mM/90 min/pH 6.0 with one factor at a time approach and numerical optimization with central composite design, respectively. Lipase-CLEAs were characterized by particle size analysis, SEM, and FTIR. Cross-linking not only shifted the optimal pH and temperature from 7.0 to 7.5 and 40-45 to 45-50 °C, but also altered the secondary structure. Lipase-CLEAs showed an increase in Km by 7.70%, and a decrease in Vmax by 16.63%. Lipase-CLEAs presented better thermostability than free lipase as evident from thermal inactivation constants (t1/2, D and Ed value), and thermodynamic parameters (Ed, ΔH°, ΔG°, and ΔS°) in the range of 50-70 °C. Lipase-CLEAs retained more than 65% activity up to four cycles and showed good storage stability for 12 days when stored at 4 ± 2 °C. They were successfully utilized for the epoxidation of lemongrass oil which was confirmed by changes in iodine value, epoxide value, and FTIR spectra.

Soy oil conjugated linoleic acid production with solar light photoisomerization.

The objectives were (1) to produce soy oil conjugated linoleic acid (CLA) triacylglycerides in large quantities with solar light photoisomerization, utilizing iodine as a photosensitizer, (2) to study the temperature variation in the photoisomerized oil during various hours of the day, and (3) to study the variations in solar light intensity during various hours of the day. A 0.5% iodine containing soy oil in glass box with a glass lid was photoisomerized, under natural solar light for 0, 11, and 27 days, and CLA isomers were determined with gas chromatography with flame ionization detector. After 27 days of solar light photoisomerization, the cis-9, trans-11 CLA; other cis, trans CLA; trans-10, cis-12 CLA; trans, trans CLA, and total CLA were found to be 0.62 ± 0.05%, 1.04 ± 0.09%, 0.54 ± 0.11%, 6.16 ± 0.68%, and 8.37 ± 0.90%, respectively. The concentration of CLA isomers between 0 and 11 days was significantly different (p < .05), and the concentration of CLA isomers between 0 and 27 days was also significantly different (p < .05). There is no significant difference (p > .05) in CLA concentration between 11 and 27 days treatment. The CLA was not found in control soy oil samples. The CLA isomers were measured with GDFID in 45 min instead of 120min. The temperature of the edible oil in glass boxes ranged from 26 °C (8 a.m.) to 56 °C (1 p.m.). The light intensity ranged from 4,146 lux (7 p.m.) to 95,490 lux (12 p.m.). Glass lid on the glass box affected light transmission to a small but statistically significant extent (p < .05). The CLA isomers could be energy efficiently and inexpensively produced in soy oil by solar light photoisomerization, at low temperature and without needing expensive reactor vessels or catalysts. PRACTICAL APPLICATION: CLA was produced effectively with the iodine sensitized solar light photoisomerization. CLA is produced in large quantities, inexpensively, for possible food additive applications. Produced CLA is in the form of stable triacylglycerides.

Dibromopinocembrin and Dibromopinostrobin Are Potential Anti-Dengue Leads with Mild Animal Toxicity.

Dengue infection is one of the most deleterious public health concerns for two-billion world population being at risk. Plasma leakage, hemorrhage, and shock in severe cases were caused by immunological derangement from secondary heterotypic infection. Flavanone, commonly found in medicinal plants, previously showed potential as anti-dengue inhibitors for its direct antiviral effects and suppressing the pro-inflammatory cytokine from dengue immunopathogenesis. Here, we chemically modified flavanones, pinocembrin and pinostrobin, by halogenation and characterized them as potential dengue 2 inhibitors and performed toxicity tests in human-derived cells and in vivo animal model. Dibromopinocembrin and dibromopinostrobin inhibited dengue serotype 2 at the EC50s of 2.0640 ± 0.7537 and 5.8567 ± 0.5074 µM with at the CC50s of 67.2082 ± 0.9731 and >100 µM, respectively. Both of the compounds also showed minimal toxicity against adult C57BL/6 mice assessed by ALT and Cr levels in day one, three, and eight post-intravenous administration. Computational studies suggested the potential target be likely the NS5 methyltransferase at SAM-binding pocket. Taken together, these two brominated flavanones are potential leads for further drug discovery investigation.

Recovery of motor function after traumatic spinal cord injury by using plasma-synthesized polypyrrole/iodine application in combination with a mixed rehabilitation scheme.

Traumatic spinal cord injury (TSCI) can cause paralysis and permanent disability. Rehabilitation (RB) is currently the only accepted treatment, although its beneficial effect is limited. The development of biomaterials has provided therapeutic possibilities for TSCI, where our research group previously showed that the plasma-synthesized polypyrrole/iodine (PPy/I), a biopolymer with different physicochemical characteristics than those of the PPy synthesized by conventional methods, promotes recovery of motor function after TSCI. The present study evaluated if the plasma-synthesized PPy/I applied in combination with RB could increase its beneficial effects and the mechanisms involved. Adult rats with TSCI were divided into no treatment (control); biopolymer (PPy/I); mixed RB by swimming and enriched environment (SW/EE); and combined treatment (PPy/I + SW/EE) groups. Eight weeks after TSCI, the general health of the animals that received any of the treatments was better than the control animals. Functional recovery evaluated by two scales was better and was achieved in less time with the PPy/I + SW/EE combination. All treatments significantly increased ßIII-tubulin (nerve plasticity) expression, but only PPy/I increased GAP-43 (nerve regeneration) and MBP (myelination) expression when were analyzed by immunohistochemistry. The expression of GFAP (glial scar) decreased in treated groups when determined by histochemistry, while morphometric analysis showed that tissue was better preserved when PPy/I and PPy/I + SW/EE were administered. The application of PPy/I + SW/EE, promotes the preservation of nervous tissue, and the expression of molecules related to plasticity as ßIII-tubulin, reduces the glial scar, improves general health and allows the recovery of motor function after TSCI. The implant of the biomaterial polypyrrole/iodine (PPy/I) synthesized by plasma (an unconventional synthesis method), in combination with a mixed rehabilitation scheme with swimming and enriched environment applied after a traumatic spinal cord injury, promotes expression of GAP-43 and ßIII-tubulin (molecules related to plasticity and nerve regeneration) and reduces the expression of GFAP (molecule related to the formation of the glial scar). Both effects together allow the formation of nerve fibers, the reconnection of the spinal cord in the area of injury and the recovery of lost motor function. The figure shows the colocalization (yellow) of ßIII-tubilin (red) and GAP-43 (green) in fibers crossing the epicenter of the injury (arrowheads) that reconnect the rostral and caudal ends of the injured spinal cord and allowed recovery of motor function.

Powerful, transferable representations for molecules through intelligent task selection in deep multitask networks.

Chemical representations derived from deep learning are emerging as a powerful tool in areas such as drug discovery and materials innovation. Currently, this methodology has three major limitations - the cost of representation generation, risk of inherited bias, and the requirement for large amounts of data. We propose the use of multi-task learning in tandem with transfer learning to address these limitations directly. In order to avoid introducing unknown bias into multi-task learning through the task selection itself, we calculate task similarity through pairwise task affinity, and use this measure to programmatically select tasks. We test this methodology on several real-world data sets to demonstrate its potential for execution in complex and low-data environments. Finally, we utilise the task similarity to further probe the expressiveness of the learned representation through a comparison to a commonly used cheminformatics fingerprint, and show that the deep representation is able to capture more expressive task-based information.

Feed-derived iodine overrides environmental contribution to cow milk.

Diets worldwide are deficient in iodine, leading to a range of undesirable health effects at the population level. Dairy products are a primary source of iodine in diets for those populations in which iodized salt is not systematically used or available. However, the flows of iodine through dairy agroecosystems are not well understood. The aim of this research was to investigate iodine flows though the dairy agroecosystem, including the influence of atmospheric depositional inputs, environmental variables, season, husbandry, and diet. Three farm-based sampling campaigns were carried out in this investigation, with milk, soil, silage, grass, and feed iodine determined by inductively coupled plasma mass spectroscopy, and nonparametric statistical analysis tests were conducted on data sets obtained. Natural iodine inputs into the environment are dominated by atmospheric deposition, which mainly from sea spray, and thus the location of farms relative to the coast and prevailing wind direction. Herbage and silage produced from grass-based systems strongly correlated with soil iodine, yet there was a strong disconnect between soil, forage, and feed and the milk that results. This was due to the levels of iodine in supplemental feeds being approximately 10-fold higher than those in forage-derived feeds. The practice of feed supplementation, accentuated by summer housing of cows, led to elevated milk iodine.

Iodine deficiency in pregnant women in Sweden: a national cross-sectional study.

PURPOSE: Voluntary salt iodization at 50 mg/kg salt ensures adequate iodine nutrition in Swedish school-aged children, but iodine status in pregnant women is uncertain. METHODS: We conducted a cross-sectional national study of 743 pregnant women, at median gestational age of 23 weeks (IQR 9, 38), recruited from maternal health care centers. We measured: urinary iodine concentration (UIC) and urinary creatinine concentration in spot urine samples; thyroglobulin (Tg), thyroid-stimulating hormone (TSH), and total thyroxine (tT4) on dried blood spots (DBS); and thyreoperoxidase antibodies in serum samples. Data on dietary supplement use were obtained, and women were classified as supplement users (consuming multivitamins containing ≥ 150 µg iodine/day) and non-supplement users (no supplements or < 150 µg iodine/day from supplements). RESULTS: Overall median UIC [bootstrapped 95% confidence interval (CI)] was 101 µg/L (95, 108; n = 737): 149 µg/L (132, 164) in supplement users (n = 253) and 85 µg/L (79, 92) in non-supplement users (n = 440) (p < 0.001). Overall geometric mean DBS-Tg (95% CI) was 22.1 µg/L (20.8, 23.5; n = 675) and the prevalence of elevated DBS-Tg was 19%. DBS-Tg was lower in supplement users (n = 229) than in non-supplement users (n = 405) (19.1 vs 24.4 µg/L, p < 0.001). DBS-TSH, DBS-tT4, and S-TPOab positivity did not differ between the two groups. CONCLUSIONS: Pregnant women in Sweden have inadequate iodine nutrition. Women not taking iodine supplements containing ≥ 150 µg iodine/day are affected by mild iodine deficiency and are at higher risk for increased thyroid activity, while maintaining euthyroidism. Iodine intake should be improved in women both before and after conception by promotion of iodized salt instead of non-iodized salt. We urge regular monitoring of iodine status in the general Swedish population, as well as in risk groups.

[Osteoprotective effect of bread enriched with protein, dietary fiber, calcium, iron and iodine in hypoestrogen-induced osteoporosis among rats].

The search for new strategies for the prevention and control of osteoporosis is an urgent task. Functional foodstuffs and their components are of particular interest in this regard. The aim was to study the effect of bread enriched with protein, dietary fiber, calcium, iron and iodine on the state of the bone tissue of rats in a model of postmenopausal osteoporosis. Material and methods. The experiment was performed on sexually mature female Wistar rats divided into groups: K - control (sham-operated rats, not ovariectomized); О30 - osteoporosis model (animals were sacrificed 30 days after ovariectomy); groups О120 and О120+ - a model of osteoporosis (rats were sacrificed 120 days after ovariectomy). All animals were fed a standard vivary diet. For rats of the О120+ group, from the 40th to the 120th day, enriched bread was included in the diet in an amount of 6 g per 100 g of body weight per day. The bread was fortified with protein (whey protein, blood plasma proteins from farm animals), dietary fiber, calcium (eggshell), iron (purified hemoglobin) and iodized whey protein. Animals of groups K and О120 received unfortified bread in the same amount. Blood levels of total calcium (by colorimetric method), gonadotropins, testosterone, and estradiol (by enzyme-linked immunosorbent assay) were analyzed. Microtomographic evaluation of the architecture and mineral density of the trabecular part of the femur and lumbar vertebrae was performed. Histomorphological analysis of the uterus and femur of animals was performed. Results and discussion. In animals of the О120+ group, in comparison with the О120 sample, there was a decrease in blood testosterone and a marked compensatory release of follicle-stimulating hormone, while no changes were detected in the concentration of estradiol and the state of the uterus atrophied against the background of ovariectomy. There was an increase in the trabecular mineral density of the femur and lumbar vertebrae. The proportion of bone trabeculae in the total volume of the femoral metaphysis (BV/TV) in animals of the О120+ sample was 12.5±0.66% compared to 10.4±0.52% in the О120 group. The values of the structural model index (SMI) reflecting the loss of bone strength and the trabecularity coefficient (TbPf) in О120+ rats (1.44±0.07 and 5.96±0.29 1/mm) were significantly lower than these parameters in the О120 group (1.74±0.08; 9.13±0.46 1/mm, р<0.05). The micro-architectural structure of the femur in the О120+ group of rats was close to that of the О30 sample, which serves as a model of the early stage of osteoporosis (SMI 1.42±0.07; TbPf 5.55±0.28 1/mm). The percentage of bone resorption perimeter and the number of osteoclasts in the О120+ femoral trabeculae were lower than in the О120 group. In the О120+ group, active osteoblasts were observed in a significant part of the resorption cavities. Cell differentiation more was observed in the osteogenic direction than in the adipogenic direction. Conclusion. Bread enriched with protein, fiber, calcium, iron and iodine, effectively weakens osteoporosis induced by ovariectomy in rats. Its inclusion in the diet may be beneficial for the prevention and treatment of systemic postmenopausal osteoporosis.

Technology for Triple Fortification of Salt with Folic Acid, Iron, and Iodine.

As many of the maternal and child health complications result from folic acid, iron, and iodine deficiencies; it makes sense to combat these simultaneously. We have developed cost-effective technology to deliver these three micronutrients simultaneously through salt. Our goal was to retain at least 70% of the micronutrients during 6 months of storage. The fortified salt was formulated by spraying a solution that contained 2% iodine and 0.5% or 1% folic acid onto salt and adding encapsulated ferrous fumarate. The formulated triple fortified salt contained 1,000 ppm iron, 50 ppm iodine, and 12.5 or 25 ppm folic acid. The spray solution and the salt were stored for 2 and 6 months respectively at 25, 35, and 45 °C 60 to 70% relative humidity. Even at 45 °C, over 70% of both iodine and folic acid were retained in the salt. The best formulation based on the color of the salt and stability of iodine and folic acid contained 12.5 ppm folic acid, 50 ppm iodine, and 1,000 ppm iron. These results indicate that iron, iodine, and folic acid can be simultaneously delivered to a vulnerable population through salt using the technology described. Also, the quality control of the process can be developed around pteroic acid that was detected as a primary degradation product of folic acid. PRACTICAL APPLICATION: The technology developed is already transferred to India for industrial scale up. When fully operational, the technology will simultaneously solve iron, iodine, and folic acid deficiencies in vulnerable populations at a very low cost.

Improvement of sea fennel (Crithmum maritimum L.) nutritional value through iodine biofortification in a hydroponic floating system.

Sea fennel is an herbaceous aromatic and edible halophyte, naturally occurring in coastal areas of the Mediterranean basin. Besides its scientific interest as a salt-tolerant species it exhibits considerable nutritional value and economical potential. As sea fennel is distributed in maritime areas, where natural iodine is available in high concentrations, the aim of this study was to evaluate whether sea fennel has the potential to accumulate elevated iodine concentrations under cultivation. A biofortification experiment in a hydroponic system applying two forms of iodine, KI and KIO3 in different concentrations was set up and monitored using sophisticated targeted elementary and metabolite analysis. The biofortification potential and possible effects on nutritional value were investigated. This study revealed that both iodine forms increased the iodine content of sea fennel tissues. Nutritional and health promoting components, biomass production but also antioxidant potential were stable or even improved under the iodine treatments.

Enhanced Z-isomerization of tomato lycopene through the optimal combination of food ingredients.

In tomatoes, most lycopene is present in the all-E-configuration and shows very low bioavailability, whereas the Z-isomers show higher bioavailability. Hence, for health reasons, it is expected that the ingestion of lycopene Z-isomers is preferable. Very recently, it was reported that onion and possibly garlic promoted thermal Z-isomerization of (all-E)-lycopene but there are no reports for other food ingredients. Here we show new food ingredients that enhance thermal Z-isomerization of lycopene in tomatoes and from the results, we guessed some causative components having the Z-isomerization promoting effect. A comprehensive investigation of food ingredients revealed that some vegetables (Allium sp., Brassica sp., and Raphanus sp.), shiitake mushroom (Lentinus edodes), and some edible seaweeds (Saccharina sp. and Ecklonia sp.) markedly promoted Z-isomerization of (all-E)-lycopene in tomato puree with heating at 80 °C for 1 h. Moreover, it was revealed that polysulfides, isothiocyanates, carbon disulfide, and iodine, which were commonly contained in the above food ingredients in considerable quantity, enhanced thermal Z-isomerization of (all-E)-lycopene. Our findings on the food ingredients and the food-derived catalysts having a carotenoid Z-isomerization promoting effect are important, not only for the food, drink, and dietary supplement manufacturing industries, but also for daily home cooking.

Rational Design of Modified Oxobacteriochlorins as Potential Photodynamic Therapy Photosensitizers.

The modulation of the photophysical properties of a series of recently synthetized oxobacteriochlorins with the introduction of heavy atoms in the macrocycles, was investigated at density functional level of theory and by means of the time-dependent TDDFT formulation. Absorption frequencies, singlet-triplet energy gaps and spin-orbit coupling (SOC) constants values were computed for all the investigated compounds. Results show how the sulfur- selenium- and iodine-substituted compounds possess improved properties that make them suitable for application in photodynamic therapy (PDT).

Preparation of hydroxylated lecithin complexed iodine/carboxymethyl chitosan/sodium alginate composite membrane by microwave drying and its applications in infected burn wound treatment.

Improving the antibacterial properties of membrane wound dressings of natural polymers is crucial. Iodine is an important safe inorganic antibacterial agent, but was confined in the composition with polymer membranes due to the challenges of homogeneity and stability during drying. In the present work, iodine was complexed with hydroxylated lecithin (HL) to improve its stability and complexing efficiency for the composition with carboxymethly chitosan/sodium alginate. With the aid of microwave drying, hydroxylated lecithin complexed iodine/carboxymethly chitosan/sodium alginate (HLI/CMCS/SA) composite membranes with homogeneously distributions of HLI, high contents of activated iodine, good mechanical and swelling properties, proper water vapor permeability, pH controllable iodine release and excellent antibacterial properties were prepared. The composite membranes exhibited high repairing efficiencies for the infection of a rat model of the seawater immersed wound infection of deep partial-thickness burns. This novel antibacterial composite membrane can be potentially used as a high performance wound dressing for treating and repairing open trauma infections.

Immunomodulatory activity of marine natural products: Synthesis, spectral characterization and toxicity assessment of natural and related synthetic iodinated tyramides.

The toxicity of natural marine iodoarenes or their synthetic counterparts is widely unknown despite the fact that triiodothyronine and thyroxine are members of this class. In this work we aimed to expand such knowledge on iodinated marine natural products and tested an ascidian (Didemnum rubeum) metabolite, N-(3,5-diiodo-4-methoxyphenethyl)benzamide, together with closely related synthetic iodinated tyramides: N-(2,5-diiodo-4-methoxyphenethyl)benzamide, N-(3-iodo-4-methoxyphenethyl)benzamide, N-(4-methoxyphenethyl)benzamide, and N-(3-iodo-4-methoxyphenethyl)formamide, for their effect on the viability of rat macrophages, as well as acute toxicity on Artemia salina. The tested tyramides exerted a varying degree of toxicity towards brine shrimps, but in certain cases, the determined lethal concentrations were even lower than those of known toxicants (e.g. strychnine sulfate, SDS). The toxicity was highly dependent on the structure of these mutually related compounds, while the natural one was shown to be the most toxic. In the case of macrophage cultures, the tested tyramides exerted much less toxicity but were found to have an effect on the functioning of these normal immune cells. The samples of the tyramides were obtained by synthesis, and were fully structurally and spectrally characterized, which also provided corroboration of the proposed structure of the natural product originally isolated in minute amounts.

Magnetite- and Iodine-Containing Nanoemulsion as a Dual Modal Contrast Agent for X-ray/Magnetic Resonance Imaging.

Noninvasive diagnostic by imaging combined with a contrast agent (CA) is by now the most used technique to get insight into human bodies. X-ray and magnetic resonance imaging (MRI) are widely used technologies providing complementary results. Nowadays, it seems clear that bimodal CAs could be an emerging approach to increase the patient compliance, accessing different imaging modalities with a single CA injection. Owing to versatile designs, targeting properties, and high payload capacity, nanocarriers are considered as a viable solution to reach this goal. In this study, we investigated efficient superparamagnetic iron oxide nanoparticle (SPION)-loaded iodinated nano-emulsions (NEs) as dual modal injectable CAs for X-ray imaging and MRI. The strength of this new CA lies not only in its dual modal contrasting properties and biocompatibility, but also in the simplicity of the nanoparticulate assembling: iodinated oily core was synthesized by the triiodo-benzene group grafting on vitamin E (41.7% of iodine) via esterification, and SPIONs were produced by thermal decomposition during 2, 4, and 6 h to generate SPIONs with different morphologies and magnetic properties. SPIONs with most anisotropic shape and characterized by the highest r2/ r1 ratio once encapsulated into iodinated NE were used for animal experimentation. The in vivo investigation showed an excellent contrast modification because of the presence of the selected NEs, for both imaging techniques explored, that is, MRI and X-ray imaging. This work provides the description and in vivo application of a simple and efficient nanoparticulate system capable of enhancing contrast for both preclinical imaging modalities, MRI, and computed tomography.