Hydrophilic Vitamin Research Articles

Diffusion mechanism and release profile of a multivitamin from TiO2 hollow particles

The present study aimed to control the release rate profile of a multivitamin that has hydrophilic and hydrophobic properties and to investigate its diffusion rate from titanium dioxide (TiO2) hollow particles. The TiO2 hollow particles encapsulating the vitamins C and E were prepared via a sol-gel process using an inkjet nozzle. The obtained particles were evaluated by scanning electron microscopy and energy dispersive X-ray spectroscopy. The sustained release rate was estimated by the dialysis bag method. Additionally, a diffusion mechanism for the multivitamin from the TiO2 hollow particles was proposed.TiO2 particles prepared by this method exhibited spherical porous structures. The TiO2 hollow particles were successful in encapsulating both the hydrophilic vitamin C and the hydrophobic vitamin E, resulting in a sustained release profile for these two components from the TiO2 hollow particles. The release behavior of the multivitamin was quite different from that of each single vitamin. This is related to the adsorption state of each vitamin on the TiO2 particle surface. The effective diffusion coefficient of VC derivative (8.403 × 10−13 cm2/s) was faster than that of VE derivative (1.671 × 10−13 cm2/s). This tendency may be attributed to the difference between hydrophilic and hydrophobic properties. Additionally, the value of effective diffusion coefficient in multi-component was always larger than that in single component. The value of Knudsen diffusion coefficient in VC and VE derivative was 2.684 × 10−3 and 2.264 × 10−3 cm2/s, respectively. In all samples, Knudsen diffusion coefficient was larger than molecular diffusion coefficient. The diffusion mechanism of the active ingredients likely depends on the pore size of TiO2 and the molecular size of the active ingredients.

The effect of chronic vitamin deficiency and long term very low dose exposure to 6 pesticides mixture on neurological outcomes – A real-life risk simulation approach

We investigate the long-term effect of very-low dose exposure to a mixture of six pesticides associated with hydrophilic vitamin deficiency on the neurobehavioral outcomes of rats. Two hundred Wistar rats were divided into four groups, two control groups, a vitamin sufficient control group and a vitamin deficiency control group and 2 test groups, a vitamin sufficient test group, and a vitamin deficiency group. The test groups were exposed for 9 months to a mixture of diquat, imazamox, imazethapyr, tepraloxydin, bentazone and acifluorfen in doses of 0.01xNOAEL (mg/kg bw/day). After 9 months of exposure, the behavior changes were evaluated by open field test and elevated plus maze test and the memory was assessed by passive avoidance test. Chronic vitamin deficiency decreased locomotor and special orientation activity and increased anxiety-like behavior in rats. Exposure to very low doses of a mixture of 6 pesticides caused central nervous effects, manifested as decreased locomotor activity, and increased anxiety levels. Vitamin deficiency and low dose chronic pesticides mixture exposure thus affected the central nervous system, especially long-term memory.

Hydrophilic and salt responsive polymers promote depletion aggregation of bacteria

Stimuli responsive, smart materials are extensively used as drug delivery carriers, antifouling surfaces, and as sensing and actuation devices. Among these materials; hydrophilic, neutral and biocompatible polymers are especially interesting for their strong water absorption properties, which makes them useful for a variety of applications in biotechnology and biomedicines. One example of neutral, hydrophilic and stimuli responsive polymer is poly(ethylene glycol) (PEG), which exhibits excellent antifouling and salt-responsive properties in solution. Herein, we present the synthesis and stimuli responsive properties of PEG-like hydrophilic polymers, and the study of their antibacterial and antifouling properties. The synthesis of novel hydrophilic vitamin B5 analogous polymers, namely poly(B5AMA), of different molecular weights and cross-linking densities is achieved by free radical polymerization method. The neutral polymers of different sizes and cross-linking densities prepared are then evaluated for their salt-responsive, antifouling and biocompatible properties in vitro.

Encapsulation of vitamin B12 into nanoengineered capsules and soft matter nanosystems for targeted delivery

Targeted delivery of vitamins to a desirable area is an active branch in a modern pharmacology. The most important and difficult delivery of vitamin B12 is that to bone marrow and nerve cells. Herein we present a first step towards the development of two types of smart carriers, polymer capsules and lyotropic liquid-crystalline nanosystems, for vitamin B12 targeted delivery and induced release. A vitamin B12 encapsulation technique into nanoengineered polymeric capsules produced by layer-by-layer assembling of polymeric shells on CaCO3 templates has been developed. The effectiveness of the process was demonstrated by optical absorption spectroscopy, transmission electron microscopy (TEM), atomic force microscopy (AFM) and small-angle X-ray diffraction. TEM and AFM analyses performed on capsules after their drying, confirmed the presence of the vitamin B12 inside the capsules in the form of crystalline nanoaggregates, 50–300 nm in diameter. Soft lipid nanovectors consisting of amphiphilic phytantriol molecules, which in water excess spontaneously self-assembly in 3D well-ordered inverse bicontinuous cubic bulk phase, were used as alternative carriers for vitamin B12. It was shown that about 30% of the vitamin added in the preparation of the soft lipid system was actually encapsulated in cubosomes and that no structural changes occurred upon loading. The Vitamin stabilizes the lipid system playing the role of its structure-forming element. The biocompatible nature, the stability and the feasibility of these systems make them good candidates as carriers for hydrophilic vitamins.

Tailoring the surface chemistry of SiO2-based monoliths to enhance the selectivity of SALDI-MS analysis of small molecules

Due to their 3D geometry, surface chemistry, high porosity and large surface area, SiO2-based monoliths were explored as novel surface-assisted laser desorption/ionization-mass spectrometry (SALDI-MS) substrates for the sensitive and selective detection of small molecules of varying polarities. For this purpose, the surface of a hydrophilic SiO2 monolith was functionalized with moderately hydrophobic C-8 and more hydrophobic C-18 groups to form C8-SiO2 and C18-SiO2 monoliths, respectively. These monoliths were characterized using N2 adsorption-desorption, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). All of the monoliths displayed V isotherms and H1-type hysteresis loops, and they had surface areas of no less than 400 m2 g−1. The presence of bands at 2853 and 2927 cm−1 in the FTIR spectra of the respective C8-SiO2 and C18-SiO2 monoliths demonstrated that they contained alkyl chains on their surfaces. A proof-of-concept study was conducted to assess the ability of the SiO2-based monoliths to serve as substrates for SALDI-MS analysis of small molecules, including hydrophilic vitamin C, moderately hydrophobic caffeine and hydrophobic carbazole. When the hydrophilic SiO2 monolith was used as the SALDI substrate, the spectrum of vitamin C showed a large molecular ion signal, while that of carbazole exhibited only an insignificant ion signal. By contrast, the use of the hydrophobic monolith C18-SiO2 led to a high intensity molecular ion signal in the SALDI spectrum of nonpolar carbazole, while the spectrum of vitamin C showed a minimal ion signal. The observed selectivities appear to be a consequence of strong interactions occurring between the substrates and analytes of matching polarities that prevent early laser irradiation-induced analyte desorption. Furthermore, the studies showed that the more hydrophobic monolith C18-SiO2 displayed higher selectivity toward enhancing the SALDI signal of the longer chain fatty acid arachidic acid (C20), while the hydrophilic SiO2 monolith was highly selective in promoting shorter chain myristic acid (C14). In addition, the feasibility of using the C18-SiO2 monolith for SALDI detection of the hydrophobic antidepressant drugs desipramine and trimipramine in carbonated malt beverages was also evaluated. The results showed that this monolith enabled the detection of the protonated forms of these drugs, with respective limits of detection (LODs) of 10 µg mL−1 and 1 ng mL−1. This proof-of-principle study demonstrates that SiO2-based monoliths are potentially important SALDI substrates for the selective enhancement of SALDI signals of a vast range of small molecule analytes.

A comparative study of monoaxial and coaxial PCL/gelatin/Poloxamer 188 scaffolds for bone tissue engineering

Structure of fibrous scaffolds varies depending on the electrospinning method and parameters which will define cell fate. In this study, monoaxial and coaxial electrospun PCL/gelatin/P-188 scaffolds were characterized in terms of morphology, chemistry, mechanical property, water retention, weight loss, porosity and release properties. Coaxial fibers supported duel release of model hydrophilic protein (Beta-lactoglobulin) and hydrophobic agent vitamin K2. Novel PCL/P-188(Shell):Gelatin/P-188(Core) coaxial scaffold had superior stability, average weight loss, no swelling behavior, controlled release of Beta-lactoglobulin and vitamin K2, enhanced Saos-2 cell viability and ALP activity and could be a good candidate as a bone tissue scaffold.

The content of selected vitamins and iodine in mare’s milk

The aim of the study was to contribute to scarce literature data on the content of selected vitamins and iodine in mare’s milk. The study focused on the content of selected lipophilic vitamins (A, E), hydrophilic vitamins B1, B2, B6) and iodine in milk samples obtained from 8 mares during 6 months of lactation. The content of micronutrients was evaluated according to the stage of lactation. Vitamins B2 and B6 were determined using ion-pair reversed phase high performance liquid chromatography with fluorescence detection, vitamin B1 by fluorescence detection by reversed-phase liquid chromatography, vitamins A and E by the ultra-high performance liquid chromatography method with ultraviolet and fluorescence detection and iodine by the spectrophotometric method. Mean concentrations of vitamins A (0.06 ± 0.08 mg/l), E (0.083 ± 0.14 mg/l), B1 (256.24 ± 44.19 µg/l), B2 (111.40 ± 81.88 µg/l), B6 (0.30 ± 0.12 mg/l) reached lower values in mare’s milk compared to cow’s milk. The mean value of iodine in mare’s milk reached 44.48 ± 54.45 µg/l. Lactation stage proved to be a significant factor for vitamin B6 and iodine.

An innovative method for synthesis of imprinted polymer nanomaterial holding thiamine (vitamin B1) selective sites and its application for thiamine determination in food samples

Thiamine is a highly hydrophilic vitamin which is insoluble in common organic solvents, utilized traditionally for synthesis of molecularly imprinted polymer. In this work a simple strategy is introduced to overcome the insolubility problem of thiamine and prepare an efficient MIP in chloroform. Thiamine, as a cationic agent, involved in an ion-pair complex with anionic species of trimethylsilyl-propane sulfonate (TPS). The ion-pair was then transferred effectively to apolar solvent of chloroform where the polymerization reaction was conducted to produce nano-sized thiamine imprinted polymer. The experimental conditions such as pH, ionic strength and carrier agent/thiamine mole ratio were optimized to maximize the thiamine amount, transported to chloroform. The characteristics of the polymer were investigated by FT-IR, SEM and Zeta potential analysis techniques. The experimental adsorption isotherms of thiamine onto MIP and non-imprinted polymer (NIP) were determined and well fitted by Langmuir-Freundlich model. Maximum binding capacities of the MIP and NIP materials were obtained as 106.1 and 35.7 μmol g−1, respectively. After investigation and fixing of the experimental conditions on thiamine extraction by the MIP, it was successfully utilized for thiamine extraction from food samples and its determination by fluorimetric method.

A novel multi-tiered experimental approach unfolding the mechanisms behind cyclodextrin-vitamin inclusion complexes for enhanced vitamin solubility and stability

This study was conducted to provide a mechanistic account for understanding the synthesis, characterization and solubility phenomena of vitamin complexes with cyclodextrins (CD) for enhanced solubility and stability employing experimental and in silico molecular modeling strategies. New geometric, molecular and energetic analyses were pursued to explicate experimentally derived cholecalciferol complexes. Various CD molecules (α-, β-, γ-, and hydroxypropyl β-) were complexed with three vitamins: cholecalciferol, ascorbic acid and α-tocopherol. The Inclusion Efficiency (IE%) was computed for each CD-vitamin complex. The highest IE% achieved for a cholecalciferol complex was for ‘βCDD3-8’, after utilizing a unique CD:cholecalciferol molar synthesis ratio of 2.5:1, never before reported as successful. 2HPβCD-cholecalciferol, γCD-cholecalciferol and α-tocopherol inclusion complexes (IC's) reached maximal IE% with a CD:vitamin molar ratio of 5:1. The results demonstrate that IE%, thermal stability, concentration, carrier solubility, molecular mechanics and intended release profile are key factors to consider when synthesizing vitamin-CD complexes. Phase-solubility data provided insights into the design of formulations with IC's that may provide analogous oral vitamin release profiles even when hydrophobic and hydrophilic vitamins are co-incorporated. Static lattice atomistic simulations were able to validate experimentally derived cholecalciferol IE phenomena and are invaluable parameters when approaching formulation strategies using CD's for improved solubility and efficacy of vitamins.

Characterization and Evaluation of Skin Permeation of Tocopheryl Phosphoric Acid-loaded Phospholipid Nanoparticles.

Tocopheryl phosphoric acid (TPA, a hydrophilic vitamin E derivative) loaded liposome and glycerin containing phospholipid nanoparticles (GPLNP) were prepared using the film rehydration and extrusion method. Nanoparticle formulations were evaluated for size, zeta potential, and in vitro permeation across hairless mouse skin, and 31P NMR spectral analysis was performed. The prepared formulations were stable for 2 weeks, and their mean nanoparticle size varied between 90 and 140 nm. Although glycerin did not affect the particle size of the empty (no TPA) system, TPA-loading resulted in the reduction of particle size and conferred a negative charge. The 31P NMR spectral analysis showed that the presence of glycerin in the formulation changed the nanoparticle structure from a bilayer to a nonbilayer. Moreover, it was suggested that TPA molecules interacted with phospholipid by entrapping nanoparticles in the formulations. TPA did not permeate across the hairless mouse skin after 48 h. However, the TPA concentration in the hairless mouse skin after permeation study increased in the nanoparticle systems and the 30% GPLNP formulation was the best formulation for the accelerated TPA permeation in the hairless mouse skin. These results demonstrate that 30% GPLNP improved TPA permeation in the hairless mouse skin model. And it was strongly suggested that glycerin has an important role for changing the structure of nanoparticles and enhancing the skin permeation of TPA.

The Optimum Conditions of Carboxymethyl Chitosan Synthesis on Drug Delivery Application and Its Release of Kinetics Study

In this paper, carboxymethyl chitosan (CMC) was synthesized and studied as a carrier to encapsulate vitamin (as drug model) and controlled release. Chitosan (CS) is a polycationic derivated from chitin, which suitable for active substance carrier system on biomedical function. CS has good properties such as non-toxic, biodegradable, and biocompatible. However, CS insoluble in an aqueous solvent so CS was modified chemically into CMC. CMC was formed by reacting CS and monochloroacetic acid with sodium hydroxide (NaOH) as a catalyst. Optimation was performed by varying the NaOH concentration during alkalizing the CS and the temperature reaction. The functional group and crystallinity of CS and CMC were estimated by FTIR and XRD. The degree substitution of carboxymethylation has an average value of 0.60. The results show optimum temperature reaction and NaOH concentration were 60 °C and 40% (w/v). The nicotinamide (NA), a hydrophilic vitamin, was loaded within CMC matrix system through in vitro precipitation method. To confirm the encapsulation of NA in CMC and the release kinetics of NA from CMC in distilled water was studied through UV-Vis spectrophotometry. The release profile of NA from CMC matrix system carried out for 3 h and 12 h. The rate of NA release from CMC increases with increasing time and the follows a zero order, Higuchi, and Korsmeyer-Peppas kinetics rules.

The effects of pH, pepsin, exchange cation, and vitamins on aflatoxin adsorption on smectite in simulated gastric fluids

Aflatoxins are toxic secondary fungal metabolites that are present in a variety of crops. Adding bentonites to aflatoxin contaminated feed could reduce the toxicity to animals, yet a complete toxicity protection has not been achieved. The aflatoxin (AfB1) adsorption by bentonite in the gastrointestinal tract could be hindered by the competition of proteins and other nutrients. The objectives of this study were to evaluate 1) the effect of simulated gastric fluid protein (pepsin) and pH on aflatoxin adsorption by smectite, 2) the influence of the exchangeable cation of smectite on the aflatoxin adsorption in simulated gastric conditions, 3) the competition of vitamins with aflatoxin molecules for adsorption sites on the smectite, and 4) the aflatoxin adsorption in the presence of vitamin B1 in the simulated fluid.Aflatoxin adsorption isotherms were performed in water and simulated gastric fluids for smectites saturated with Na, Ca and Ba. The intercalation of pepsin in the smectite was confirmed with XRD and FTIR. The vitamin (B1, D and E) interaction was quantified with adsorption isotherms, too. Aflatoxin adsorption on smectite was reduced in the simulated gastric solution, due to the intercalation of pepsin onto the smectite. The exchangeable cation showed low or negligible effect on the aflatoxin adsorption in the simulated GF. Vitamin B1 was adsorbed by the clay.Proteins and hydrophilic vitamins competed with aflatoxin molecules for adsorption sites on smectite. In the interlayer space of smectite, large molecules as pepsin could block the hydrophobic sites required for aflatoxins. Yet, vitamin B1 could compete with proteins and enhance the adsorption of aflatoxin by yielding the hydrophobic domains on smectite surface.

Characterization of partitioning behavior of vitamins in micellar systems using affinity capillary electrophoresis

Introduction: Micellar Electrokinetic Chromatography, sometimes referred as Affinity Capillary Electrophoresis, is a useful tool to the characterization of the drug partitioning in different vehicle systems such as micelles and microemulsions using the capacity factor as hydrophobicity parameter. Bile acids, because of their important role in biological systems, are applied widely in ACE method to characterization of partition properties of solutes. In this paper the interaction of some hydrophilic and lipophilic vitamins with micellar systems consisted of bile salts and phospholipids was considered using ACE. Material and Methods: Three mixed micelles and one microemulsion were employed. The samples were filtered through a 0.45 μm filter. 13 vitamins, consist of 4 lipophilic and 9 hydrophilic vitamins were investigated. Each vitamin was solved in different micellar systems (0.1 mg/ml). Then, using ACE, the electropherogram of samples was obtained under certain run conditions. The capacity factor for each sample was calculated according the migration times in the electropherogram. DMSO and Sudan red were used as EOF tracer and micelle tracer respectively. All experiments were carried out with certain instrumental conditions. Results and Discussion: The results show that the migration times of lipophilic vitamins are equal to migration time of micellar tracer and consequently the capacity factor of all of them tends to infinity. In fact these vitamins, concerning the hydrocarbonic chain in their chemical structure, are incorporated in the inner oil core of mixed micelle or microemulsion and moved with it. Four hydrophilic vitamins (niacinamid, pyridoxine, D-panthenol and cyanocobalamin) have different affinity to Micellar systems. But for each vitamin the affinity to different system is almost same. K′ zero means that vitamin has not any affinity to micelle, remains in aqueous phase and moves with EOF. Five hydrophilic vitamins (ascorbic acid, folic acid, riboflavin, biotin and thiamin) had charged behavior. The electrophoretic mobility of all these vitamins was negative, except thiamin which has positive mobility. Two important parameters that may influence these migration behaviors of charged solutes are pH and micelle concentration. Distribution properties of molecules mostly change depending to pH value of the media because of the effect of pH on the chemical interaction. In the other hand, it might be that the negative charge of bile salt's micelle increases by mixing with phospholipids, and causes to stronger repulsion between negative charged micelle and anion analyte. So the electrophoretic mobility of anionic vitamins in presence of micelle would be reduced. Conclusion: The MEKC technique as a method of ACE was employed to determination partitioning pattern of various kinds of vitamins in a micellar solutions. The affinity of both hydrophilic and lypophilic vitamins to micellar system was investigated by calculation the capacity factor. This value for lypophilic vitamins is infinite, because they incorporate with micelle compositions and moved with them. In contrast hydrophilic vitamins exhibited different partitioning behaviour in micellar solution. The negative value obtained for anionic hydrophilic vitamins can be corrected by change some condition like micellar concentration and the pH of media.

Stability of hydrophilic vitamins mixtures in the presence of electrolytes and trace elements for parenteral nutrition: A nuclear magnetic resonance spectroscopy investigation

In total parenteral nutrition (TPN), especially in the case of preterm infants, simultaneous administration of vitamins and trace elements is still a problematic issue: guidelines put in evidence the lack of specific documentation. In this work NMR spectroscopy was applied to the study of vitamins (pyridoxine hydrochloride, thiamine nitrate, riboflavin-5′-phosphate and nicotinamide) stability in presence of salts and trace elements. Vitamins in D2O were first analyzed by 1H NMR spectroscopy in absence of salts and trace elements; changes in chemical shifts or in diffusion coefficients, measured by NMR DOSY technique, were analyzed. The effects of salts and trace elements on single vitamins and on their admixtures were then investigated by performing quantitative analyses during 48h. Selected vitamins are subject to intermolecular interactions. No degradative effects were observed in presence of salts and trace elements. Only riboflavin-5′-phosphate is subject to precipitation in presence of divalent cations; however, at low concentration and in presence of other vitamins this effect was not observed. Solutions analyzed, in the condition of this study, are stable for at least 48h and vitamins and trace elements can be administered together in TPN.

Some Phytochemicals and Hydrophilic Vitamins of Anacardium occidentale

Some Phytochemicals and Hydrophilic Vitamins of Anacardium occidentale

Comparative study of encapsulation of vitamins with native and modified soy protein

Microencapsulation of hydrophobic (α-tocopherol) and hydrophilic (ascorbic acid) vitamins by native (non-modified) and modified soy protein isolate (SPI) was carried out using a spray-drying technique. Proteins' functional properties were modified by acylation and cationization reactions in aqueous alkaline media. The results obtained demonstrated that SPI modification resulted in decreased emulsion droplet size and viscosity. All preparations with ascorbic acid (AA) had lower viscosity and microparticle size than those with α-tocopherol (T). Moreover, grafting of fatty acid chains to SPI by acylation improved its amphiphilic character and affinity with hydrophobic substances. Thus, the microencapsulation efficiency of T was increased from 79.7% to 94.8% and the microencapsulation efficiency of AA was reduced from 91.8% to 57.3% compared to native SPI. Conversely, attachment of quaternary ammonium cationic groups to proteinic chains by cationization, increased SPI solubility and favored the AA microencapsulation. This study illustrated that an appropriate modification of SPI can improve the microencapsulation efficiency of suitable active cores.

FOLICation: Engineering approved drugs as potential p53–MDM2 interaction inhibitors for cancer therapy

Cancer is characterized by uncontrolled growth of abnormal cells leading to the formation of tumors. Normally, the pro-apoptotic p53 protein plays a central role in protecting cells against carcinogenesis. In almost 50% human tumor cells, however, the p53 protein is dysregulated by direct interaction with its negative regulator, the Murine Double Minute 2 (MDM2) protein. Therefore, blocking the p53-binding pocket on MDM2, leading to the activation of tumor suppressor p53 presents a novel therapeutic strategy against several types of cancers. The published crystal structure of MDM2 bound with the p53 binding domain has revealed that three key hydrophobic residues of p53 are buried deep into the binding cavity of MDM2 and thus are central to p53–MDM2 binding. Accordingly, several low-molecular-weight compounds have been developed that mimic these three hydrophobic residues and thus bind to the MDM2 pocket, leading in turn to inhibition of the deleterious p53–MDM2 interaction. It is noteworthy that these inhibitors also possess an additional hydrophilic group that is shown to be necessary as a “cover” protecting the hydrophobic interaction surface between inhibitor and MDM2 from surrounding solvent. In comparison, several FDA-approved drugs possess the three key hydrophobic features necessary for binding to MDM2, but lack the fourth hydrophilic moiety, thus possibly hindering their ability as potential p53–MDM2 interaction inhibitors. Therefore, we hypothesize that conjugation of hydrophilic vitamin folic acid or its analogs to these drugs (termed “FOLICation”) may provide them with the much-needed hydrophilic cover and make them suitable for investigation as potentially novel p53–MDM2 inhibitors. We also anticipate that FOLICation of these drugs may further lead to their enhanced and selective uptake by cancer cells, owing to the significantly higher expression of folic acid receptors on cancer cells compared to normal cells.

Thin-layer chromatography with stationary phase gradient as a method for separation of water-soluble vitamins

The group of hydrophilic vitamins play an important role in human health, and their lack or excess produces specific diseases. Therefore, the analysis of these compounds is indispensable for monitoring their content in pharmaceuticals and food in order to prevent some human diseases. TLC was successfully applied in the analysis of hydrophilic vitamins, but the most difficult problem in the simultaneous analysis of all these compounds is to find an optimum stationary phase-mobile phase system due to different chemical characteristics of analytes. Unfortunately structural analogues are difficult to separate in one chromatographic run, and this is the case in hydrophilic vitamins investigations. TLC gives the possibility to perform two-dimensional separations by using stationary phase gradient achieving the highest resolution by combining two systems with different selectivity. The goal of this work was to develop a method of analysis enabling separation of hydrophilic vitamins using TLC with adsorbent gradient. The developed method was used for identifying the water-soluble vitamins in alcoholic extracts of Hippophae rhamnoides and of Ribes nigrum.

Effect of size on the cellular endocytosis and controlled release of mesoporous silica nanoparticles for intracellular delivery

Due to the unique physicochemical properties and membrane-permeable capacity, mesoporous silica nanoparticles (MSNs) are considered as an ideal carrier for intracellular delivery. Herein, we endeavored to address the size effect of MSNs on the cellular uptake, endosomal escape and controlled release, the key steps for the intracellular delivery. The well-ordered MSNs in the range from 55-nm to 440-nm with similar pore texture were prepared by modified base-catalyzed sol-gel method. With MC3T3-E1 model cell line, the in vitro results indicated that after 12h cultivation, MSNs within 55 ~ 440nm could all be internalized into the cells, and further escaped out of the endosomal compartment. The efficiency of the cellular uptake and endosomal escape strongly depended on the particle size, with the best efficiencies from 100-nm MSNs. Furthermore, the MTT results indicated that these MSNs materials were all biocompatible. The controlled release experiments with hydrophobic dexamethasone and hydrophilic vitamin C as models showed that for these small-molecular drugs, the loading amount all mainly determined by the surface area of the MSNs, and the subsequent release of the drug dramatically decreased with the increasing of the particle size. By contrast, the release rate of vitamin C was much quicker than that of the dexamethasone. These findings presented here could provide new means to tailor the size of MSNs and thus to guide the design of MSNs-based intracellular delivery system. Due to the good cell biocompatibility, high cellular uptake and endosomal escape, we conjectured that the 100-nm MSNs are more favorable for the intracellular delivery of drugs in live cells.

Milk and Dairy Products: A Unique Micronutrient Combination

Milk and dairy products contain micronutrients such as minerals and vitamins, which contribute to multiple and different vital functions in the organism. The mineral fraction is composed of macroelements (Ca, Mg, Na, K, P, and Cl) and oligoelements (Fe, Cu, Zn, and Se). From a physicochemical point of view, the chemical forms, the associations with other ions or organic molecules, and the location of macroelements such as Ca, Mg, Na, K, P, and Cl in milk are relatively well described and understood. Thus, it is admitted that these macroelements are differently distributed into aqueous and micellar phases of milk, depending on their nature. K, Na, and Cl ions are essentially in the aqueous phase, whereas Ca, P, and Mg are partly bound to the casein micelles. About one third of the Ca, half of the P, and two thirds of the Mg are located in the aqueous phase of milk. Dairy products are more or less rich in these different minerals. In cheeses, mineral content depends mainly on their processing. The Ca content is strongly related to the acidification step. Moreover, if acidification is associated with the draining step, the Ca content in the cheese will be reduced. Thus, the Ca content varies in the following increasing order: milks/fermented milks/fresh cheeses < soft cheeses < semi-hard cheeses < hard cheeses. The chemical forms and associations are less described than those present in milk. Concerning Ca, the formation of insoluble calcium phosphate, carbonate, and lactate is reported in some ripened cheeses. The NaCl content in cheeses depends on the salting of the curd. From a nutritional point of view, it is largely admitted that milk and dairy products are important sources of Ca, Mg, Zn, and Se. The vitamin fraction of milk and dairy products is composed of lipophilic (A, D, E, and K) and hydrophilic (B1, B2, B3, B5, B6, B8, B9, B12, and C) vitamins. Because of their hydrophobic properties, the lipophilic vitamins are mainly in the milk fat fraction (cream, butter). The hydrophilic vitamins are in the aqueous phase of milk. For one part of these vitamins, the concentrations described in the literature are not always homogenous and sometimes not in accordance between them; these discrepancies are due to the difficulty of the sample preparation and the use of appropriate methods for their quantification. However, there is no doubt of the significant contribution of milk and dairy products to the intake of vitamins. Milk and dairy are considered essential sources for vitamins.Key teaching points • Milk and dairy products are unique micronutrient combinations with recognized health benefits.• The concentration, chemical forms, and location of different minerals are relatively well known and described. For example, Ca is present in dairy products in different forms: free, associated with citrate, inorganic and organic phosphates, and free fatty acids.• Milk and dairy products are excellent sources of Ca, P, Mg, Zn, and Se.• The concentration of vitamins in milk and dairy products is variable and depends on several factors such as biosynthesis, animal feeding, physicochemical conditions (heat, light, O2, oxidant agents), and analytical methods for their determinations.• Vitamins A, D, E, and K are mainly located in the lipid phase and vitamins of group B and C in the aqueous phase.• Milk and dairy products are excellent sources of vitamins A, B1, B2, and B12.