Drug nanoparticle formulation using ascorbic Acid derivatives

Safety Assessment of Ascorbyl Glucoside and Sodium Ascorbyl Glucoside as Used in Cosmetics

The Expert Panel for Cosmetic Ingredient Safety (Panel) reviewed the safety of Ascorbyl Glucoside and Sodium Ascorbyl Glucoside in cosmetic products. These ingredients are reported to have the following functions in cosmetics: antioxidant, and skin-conditioning agent-miscellaneous. The Panel reviewed data relevant to the safety of these ingredients in cosmetic formulations, and concluded that Ascorbyl Glucoside and Sodium Ascorbyl Glucoside are safe in cosmetics in the present practices of use and concentration described in this safety assessment.

Incorporation of ascorbic acid-2-glucoside into ulvan microneedles to enhance its permeation for anti-aging and whitening treatment

For anti-aging and whitening treatment, ascorbic acid-2-glucoside (AA2G) was incorporated into a 4.0 % (w/v) ulvan solution at three concentrations (0.5 %, 1.0 %, and 2.0 % w/v) to fabricate ulvan-based microneedles (UMNs) using a spin-casting method, aimed at enhancing AA2G permeation. The in vitro skin insertion study demonstrated that incorporating AA2G into the UMNs improved their insertion capability, increasing from 86.3 % for neat UMNs to 98 % for AA2G-UMNs. Furthermore, in vitro drug permeation profiles revealed that dissolving UMNs significantly enhanced the cumulative permeation of AA2G, achieving 80-90 % within 3 h. In addition to showing good biocompatibility with HaCaT and NIH3T3 cells, AA2G-UMNs exhibited antioxidant activity and protected HaCaT cells from H2O2-induced oxidative stress. Their anti-aging activity was demonstrated by their ability to inhibit elastase and collagenase activity. Moreover, whitening efficacy was confirmed through the inhibition of melanin production and tyrosinase activity. Among the formulations, 2.0 % AA2G-UMNs achieved the greatest reduction in melanin content in B16F10 cells, with a 54.2 % reduction intracellularly and a 61.3 % reduction extracellularly. Tyrosinase activity inhibition by AA2G-UMNs ranged from 42.6 % to 53.4 %. These results suggest that AA2G-UMNs hold significant promise for applications in the pharmaceutical and cosmeceutical industries.

Antioxidant and Antidiabetic Properties of a Thinned-Nectarine-Based Nanoformulation in a Pancreatic β-Cell Line

Pancreatic β-cells play a crucial role in maintaining glucose homeostasis, although they are susceptible to oxidative damage, which can ultimately impair their functionality. Thinned nectarines (TNs) have gained increasing interest due to their high polyphenol and abscisic acid (ABA) content, both of which possess antidiabetic properties. Nevertheless, the efficacy of these bioactive compounds may be compromised by limited stability and bioavailability in vivo. This study aimed to develop nanoformulations (NFs) containing pure ABA or a TN extract (TNE) at an equivalent ABA concentration. Subsequently, the insulinotropic and antioxidant potential of the NFs and their unformulated (free) forms were compared in MIN-6 pancreatic cells exposed to varying glucose (5.5 mM and 20 mM) and iron (100 µM) concentrations. NF-TNE treatment exhibited enhanced antioxidant activity compared to free TNE, while ABA-based groups showed no significant antioxidant activity. Moreover, MIN6 cells incubated with both high glucose and iron levels demonstrated significantly higher insulin AUC levels after treatment with all samples, with NF-TNE displaying the most pronounced effect. In conclusion, these results highlight the additional beneficial potential of TNE due to the synergistic combination of bioactive compounds and demonstrate the significant advantage of using a nanoformulation approach to further increase the benefits of this and similar phytobioactive molecules.

Synthesis of nanostructured silica particles for controlled release of ascorbic acid: Microstructure features and In Vitro scratch wound assay

To date, the long term stability of ascorbic acid (AA) under physiological conditions represents a major issue for wound healing and tissue regeneration applications. In this study, ascorbyl phosphate (AP) was loaded into silica nanoparticles (SiNPs) through a simple one-step procedure, in which spherical shaped porous SiNPs were obtained via hydrolysis/condensation of tetraethylorthosilicate (TEOS) in the presence of bicarbonate salt and ammonia. The as-prepared SiNPs were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM) and Fourier Transformer Infrared Spectrophotometer (FTIR). Incorporation of bicarbonate salt resulted in the formation of spherical SiNPs with an average diameter of 460 ± 89 nm, while further increase of bicarbonate salt led to the formation of silica sheet-like structures. The AP-loaded SiNPs exhibited high loading efficiency from 92.3- 81.5%, according to AP content and sustained release over 3 days. According to cell viability assay, the obtained AP-enriched SiNPS showed no toxicity and supportive effect to the proliferation of human skin fibroblast cells (HSF) at a concentration less than 200 μg/mL. Moreover, it was observed that the wound closure percentage (%) after 24 h was also shown to increase to 74.1 ± 3.1% for 20AP-loaded SiNPs compared to control samples (50.1 ± 1.8%). The obtained results clearly demonstrated that the developed SiNPs formulation exhibits optimal microstructure features to maintain a sustained release of AA at wound bed for the healing of skin tissue, including acute and chronic wounds. This article is protected by copyright. All rights reserved.

Enzyme-responsive biomimetic solid lipid nanoparticles for antibiotic delivery against hyaluronidase-secreting bacteria

In this work, a potent hyaluronidase inhibitor (ascorbyl stearate (AS)) was successfully employed to design vancomycin-loaded solid lipid nanoparticles (VCM-AS-SLNs) with biomimetic and enzyme-responsive features, to enhance the antibacterial efficacy of vancomycin against bacterial-induced sepsis. The VCM-AS-SLNs prepared were biocompatible and had appropriate physicochemical parameters. The VCM-AS-SLNs showed an excellent binding affinity to the bacterial lipase. The in vitro drug release study showed that the release of the loaded vancomycin was significantly accelerated by the bacterial lipase. The in silico simulations and MST studies confirmed the strong binding affinity of AS and VCM-AS-SLNs to bacterial hyaluronidase compared to its natural substrate. This binding superiority indicates that AS and VCM-AS-SLNs could competitively inhibit the effect of hyaluronidase enzyme, and thus block its virulence action. This hypothesis was further confirmed using the hyaluronidase inhibition assay. The in vitro antibacterial studies against sensitive and resistant Staphylococcus aureus revealed that the VCM-AS-SLNs had a 2-fold lower minimum inhibitory concentration, and a 5-fold MRSA biofilm elimination compared to the free vancomycin. Furthermore, the bactericidal-kinetic showed a 100% bacterial clearance rate within 12 hours of treatment with VCM-AS-SLNs, and less than 50 % eradication after 24 hours for the bare VCM. Therefore, the VCM-AS-SLN shows potential as an innovative multi-functional nanosystem for effective and targeted delivery of antibiotics.

Improvement of ascorbic acid delivery into human skin via hyaluronic acid-coated niosomes

Hyaluronic acid (HA) as a covering agent was incorporated into the ascorbic acid (AA)-niosomes to improve the performance of AA delivery systems into the skin. The preparation method: Thin film hydration. Characterisation tests: Field emission scanning electron microscopy, fourier transform infra-red spectroscopy, dynamic light scattering, UV-Visible, zeta potential, Franz diffusion cell, and flowcytometry. The niosomes with 10% w/w HA possessed the largest mean particle diameter of 341.0 ± 48.09 nm with PDI value of 0.29 ± 0.05, and the lowest zeta potential of -38.70 ± 0.27 mv. The drug encapsulation efficiency of this sample was 56.55 ± 0.99%, and in-vitro drug release test showed AA released in two slow and fast phases. Moreover, the highest amount of drug penetration and accumulation was related to this sample, recorded 116.55 ± 7.54 and 134.8 ± 10.04 µg/cm², respectively. Niosomes coated with 10% w/w HA showed the greatest potential for improving the antioxidant activity of AA penetration into the skin.

Chemical Permeation Enhancers for Topically-Applied Vitamin C and Its Derivatives: A Systematic Review

This paper reports the permeation-enhancing properties and safety of different chemical permeation enhancers (CPEs) on the topical delivery of vitamin C (VC) and its derivatives. A literature search using search keywords or phrases was done in PubMed®, ScienceDirect, and MEDLINE databases. The calculated Log P (cLog P) values were referenced from PubChem and the dermal LD50 values were referenced from safety data sheets. Thirteen studies described the permeation-enhancing activity of 18 identified CPEs in the topical delivery of VC. Correlation analysis between ER and cLog P values for porcine (r = 0.114) and rabbit (r = 0.471) showed weak and moderate positive correlation, while mouse (r = −0.135), and reconstructed human epidermis (r = −0.438) had a negative correlation. The majority (n = 17) of the CPEs belonged to Category 5 of the Globally Harmonized System of Classification or low toxicity hazard. CPEs alone or in combination enhanced permeation (ER = 0.198–106.57) of VC in topical formulations. The combination of isopropyl myristate, sorbitan monolaurate, and polyoxyethylene 80 as CPEs for VC resulted in the highest permeation enhancement ratio.

Assessment of antifungal efficacy of itraconazole loaded aspasomal cream: comparative clinical study

Topical conveyance of antifungal agents like itraconazole ITZ has been giving good grounds for expecting felicitous antifungal medicines. The defiance of topical delivery of this poorly water soluble and high-molecular-weight drug, however, mightily entail an adequate vehiculation. ITZ aspasomes, newer antioxidant generation of liposomes, have been designed and enclosed in a cream to ameliorate skin deposition. The proposed creams containing non-formulated ITZ or encapsulated in aspasomes (0.1% or 0.5%) were topically applied in patients with diagnosed diaper dermatitis complicated by candidiasis, tinea corporis (TC), and tinea versicolor (TVC). Placebos (void aspasomal cream and cream base) were also utilized. The obtained results for diaper rash revealed that aspasomal cream (0.5% ITZ) was eminent with respect to complete cure and negative candida culture after 10-day therapy relative to counterparts containing 0.1% ITZ aspasomes or non-formulated ITZ (0.1% and 0.5%). For tinea, the same trend was manifested in terms of ‘cleared’ clinical response in 90% of patients and absence of fungal elements after 4-week treatment. Relative to non-formulated ITZ, ITZ aspasomal cream was endorsed to be auspicious especially when ITZ concentration was lowered to half commercially available cream concentration (1%), pushing further exploitation in other dermal fungal infections.

Synthesis and In Vitro Characterization of Ascorbyl Palmitate-Loaded Solid Lipid Nanoparticles

Antitumor applications of ascorbic acid (AA) and its oxidized form dehydroascorbic acid (DHA) can be quite challenging due to their instability and sensitivity to degradation in aqueous media. To overcome this obstacle, we have synthesized solid lipid nanoparticles loaded with ascorbyl palmitate (SLN-AP) with variations in proportions of the polymer Pluronic F-68. SLNs were synthesized using the hot homogenization method, characterized by measuring the particle size, polydispersity, zeta potential and visualized by TEM. To investigate the cellular uptake of the SLN, we have incorporated coumarin-6 into the same SLN formulation and followed their successful uptake for 48 h. We have tested the cytotoxicity of the SLN formulations and free ascorbate forms, AA and DHA, on HEK 293 and U2OS cell lines by MTT assay. The SLN-AP in both formulations have a cytotoxic effect at lower concentrations when compared to ascorbate applied the form of AA or DHA. Better selectivity for targeting tumor cell line was observed with 3% Pluronic F-68. The antioxidative effect of the SLN-AP was observed as early as 1 h after the treatment with a small dose of ascorbate applied (5 µM). SLN-AP formulation with 3% Pluronic F-68 needs to be further optimized as an ascorbate carrier due to its intrinsic cytotoxicity.

Biomimetic pH/lipase dual responsive vitamin-based solid lipid nanoparticles for on-demand delivery of vancomycin

In this study, ascorbyl tocopherol succinate (ATS) was designed, synthesized and characterized via FT-IR, HR-MS, H¹ NMR and C¹³ NMR, to simultaneously confer biomimetic and dual responsive properties of an antibiotic nanosystem to enhance their antibacterial efficacy and reduce antimicrobial resistance. Therefore, an in silico-aided design (to mimic the natural substrate of bacterial lipase) was employed to demonstrate the binding potential of ATS to lipase (-32.93 kcal/mol binding free energy (ΔG_bind) and bacterial efflux pumps blocking potential (NorA ΔG_bind: -37.10 kcal/mol, NorB ΔG_bind: -34.46 kcal/mol). ATS bound stronger to lipase than the natural substrate (35 times lower Kd value). The vancomycin loaded solid lipid nanoparticles (VM-ATS-SLN) had a hydrodynamic diameter, zeta potential, polydispersity index and entrapment efficiency of 106.9 ± 1.4 nm, -16.5 ± 0.93 mV, 0.11 ± 0.012 and 61.9 ± 1.31%, respectively. In vitro biocompatibility studies revealed VM-ATS-SLN biosafety and non-haemolytic activity. Significant enhancement in VM release was achieved in response to acidified pH and lipase enzyme, compared to controls. VM-ATS-SLN showed enhanced sustained in vitro antibacterial activity for 5 days, 2-fold greater MRSA biofilm growth inhibition and 3.44-fold reduction in bacterial burden in skin infected mice model compared to bare VM. Therefore, ATS shows potential as a novel multifunctional adjuvant for effective and targeted delivery of antibiotics.

Vitamin C and Cardiovascular Disease: An Update

The potential beneficial effects of the antioxidant properties of vitamin C have been investigated in a number of pathological conditions. In this review, we assess both clinical and preclinical studies evaluating the role of vitamin C in cardiac and vascular disorders, including coronary heart disease, heart failure, hypertension, and cerebrovascular diseases. Pitfalls and controversies in investigations on vitamin C and cardiovascular disorders are also discussed.

Nanoparticle-directed and ionically forced polyphosphate coacervation: a versatile and reversible core-shell system for drug delivery

A drug encapsulation/delivery system using a novel principle is described that is based on an intra-particle migration of calcium ions between a central Ca²⁺-enriched nanoparticle core and the surrounding shell compartment. The supply of Ca²⁺ is needed for the formation of a coacervate shell around the nanoparticles, acting as the core of drug-loadable core–shell particles, using the physiological inorganic polymer polyphosphate (polyP). This polyanion has the unique property to form, at an alkaline pH and in the presence of a stoichiometric surplus of calcium ions, water-insoluble and stabile amorphous nanoparticles. At neutral pH a coacervate, the biologically active form of the polymer, is obtained that is composed of polyP and Ca²⁺. The drug-loaded core–shell particles, built from the Ca–polyP core and the surrounding Ca–polyP shell, were fabricated in two successive steps. First, the formation of the nanoparticle core at pH 10 and a superstoichiometric 2:1 molar ratio between CaCl₂ and Na–polyP into which dexamethasone, as a phosphate derivative, was incorporated. Second, the preparation of the coacervate shell, loaded with ascorbic acid, by exposure of the Ca–polyP core to soluble Na–polyP and L-ascorbate (calcium salt). EDX analysis revealed that during this step the Ca²⁺ ions required for coacervate formation migrate from the Ca–polyP core (with a high Ca:P ratio) to the shell. Electron microscopy of the particles show an electron-dense 150–200 nm sized core surrounded by a less sharply delimited electron-sparse shell. The core–shell particles exhibited strong osteogenic activity in vitro, based on the combined action of polyP and of dexamethasone and ascorbic acid, which reversibly bind to the anionic polyP via ionic Ca²⁺ bonds. Drug release from the particles occurs after contact with a peptide/protein-containing serum, a process which is almost complete after 10 days and accompanied by the conversion of the nanoparticles into a coacervate. Human osteosarcoma SaOS-2 cells cultivated onto or within an alginate hydrogel matrix showed increased growth/viability and mineralization when the hybrid particles containing dexamethasone and ascorbic acid were embedded in the matrix. The polyP-based core–shell particles have the potential to become a suitable, pH-responsive drug encapsulation/release system, especially for bone, cartilage and wound healing.

Constituents Leached by Tomato Seeds Regulate the Behavior of Root-Knot Nematodes and Their Antifungal Effects against Seed-Borne Fungi

Germinating seeds can release diverse phytochemicals that repel, inhibit, or kill pathogens such as root-knot nematodes and seed-borne fungi. However, little is known about the composition of these phytochemicals and their effects on pathogens. In this study, we demonstrated that tomato seed exudates can attract the nematode Meloidogyne incognita using a dual-choice assay. Eighteen compounds were then isolated and identified from the exudates. Of these, esters (1-3), fatty acids (4-6), and phenolic acids (10-12) were proven to be the signaling molecules that facilitated the host-seeking process of second-stage juveniles (J2s) of nematodes, while alkaloids (17 and 18) disrupted J2s in locating their host. Furthermore, some phenolic acids and alkaloids showed antifungal effects against seed-borne fungi. In particular, ferulic acid (12) showed obvious activity against Aspergillus flavus (minimum inhibitory concentration (MIC), 32 μg/mL), while dihydrocapsaicin (17) showed noticeable activity against Fusarium oxysporum (MIC, 16 μg/mL). Overall, this study presents the first evidence that M. incognita can be attracted to or deterred by various compounds in seed exudates through identification of the structures of the compounds in the exudates and analysis of their effects on nematodes. Furthermore, some antifungal compounds were also found. The findings of this work suggest that seed exudates are new source for finding insights into the development of plant protective substances with nematocidal and antifungal effects.

The role of the intestinal-protein corona on the mucodiffusion behaviour of new nanoemulsions stabilised by ascorbyl derivatives

Nanoemulsions are vesicular systems with great potential for the delivery of drugs, which significantly depends on the appropriate selection of the components that constitute them. In this sense, the use of materials with adequate toxicity profiles for the oral route provides additional advantages in terms of safety concerns avoidance. This work describes the formulation of novel two-component nanoemulsions constituted by α-tocopherol and ascorbyl-palmitate derivatives. Among them, ascorbyl-dipalmitate allowed the formation of nanoemulsions with size values around 170 nm and negative charge; additionally, they showed strong antioxidant capacity. These nanoemulsions are proposed to the oral route, so their behaviour in intestinal conditions was evaluated by incubating the nanoemulsion in simulated intestinal fluid. This process led to the formation of an intestinal-protein corona (I-PC) at the colloidal surface that determined the interaction with the mucus barrier. The I-PC displaced the immobile-hindered particles towards a subdiffusive-diffusive population. These studies report for the first time the effect of the I-PC on the mucodiffusion behaviour of vesicular systems, a finding that may help to comprehend the performance of nanocarriers under intestinal conditions.

Ascorbic Acid Derivatives as Potential Substitutes for Ascorbic Acid To Reduce Color Degradation of Drinks Containing Ascorbic Acid and Anthocyanins from Natural Extracts

Ascorbic acid is widely used in the food industry as a source of vitamin C or as antioxidant. However, it degrades quickly in beverages at acidic pH and can accelerate the degradation of anthocyanins, natural dyes used in beverages, leading to a loss of color. In this work, we investigated the possibility to replace ascorbic acid by ascorbic acid derivatives to prevent its degradation effect on anthocyanins from natural extracts (black carrot, grape juice, and purple sweet potato). For this, the thermal and photolytic stabilities under air and under N₂ of ascorbic acid (as reference) and of some ascorbic acid derivatives (3-O-ethyl-l-ascorbic acid, 2-O-α-d-glucopyranosyl-l-ascorbic acid, l-ascorbic acid 2-phosphate sesquimagnesium salt hydrate, l-ascorbyl 2,6-dibutyrate, glyceryl ascorbate, (+)-5,6-O-isopropylidene-l-ascorbic acid), soluble in aqueous model beverages, were studied alone and in the presence of anthocyanins from the natural extracts in citrate buffer at pH 3. The stability was followed by UV-visible spectrometry. To extend the investigation, some properties of the ascorbic acid derivatives (pK_a, oxidation potential, bond dissociation energy, ionization potential) were also determined. Moreover, the addition of chlorogenic acid was examined to further stabilize the mixture of anthocyanins with 2-O-α-d-glucopyranosyl-l-ascorbic acid, a promising ascorbic acid derivative.

Ascorbic acid derivative-loaded modified aspasomes: formulation, in vitro, ex vivo and clinical evaluation for melasma treatment

Vitamin C (L-Ascorbic acid) has many favourable effects on the skin such as antioxidant, anti-aging and whitening effects. Its instability and low permeability limit its pharmaceutical use in cosmetic and dermatological products. Instead, Mg ascorbyl phosphate (MAP), an ascorbic acid derivative, has the same effect with higher stability is being used. In this work, a vesicular system, aspasomes, containing MAP was developed and evaluated. Aspasomes are multilayered vesicles formed by amphiphiles molecules, Ascorbyl palmitate (ASP), in combination with cholesterol and charged lipids for drug encapsulation. Here, we investigated the use of lecithin instead of the charged lipid dicetyl phosphate for aspasomes development. Nine formulations were prepared and evaluated for their entrapment efficiency, particle size, polydispersity index (PDI) and zeta potential. Their entrapment efficiency ranged from 33.00 ± 2.27 to 95.18 ± 1.06, while their particle size was from 373.34 ± 60.85 to 464.37 ± 93.46 nm with acceptable PDI (from 0.212 ± 0.068 to 0.351 ± 0.061) and zeta potential (from -37.52 ± 2.42 to -50.36 ± 1.82). Three formulations were selected and evaluated for their drug release, permeation and retention into skin. One formulation was selected to be formulated as aspasomal topical cream and gel. The aspasomal cream was found to have enhanced drug permeation and skin retention over the aspasomal gel as well as the aspasomes formulation. MAP aspasomal cream was evaluated clinically as an effective treatment for melasma against 15% trichloroacetic acid (TCA) and the results recorded that the aspasomal cream showed the greatest degree of improvement regarding the hemi-MASI scores with 35% of patients rating it as excellent treatment. The study showed that MAP aspasomal cream can be considered a novel treatment of melasma which is free of side effects. Its efficacy as a monotherapy is superior to that of chemical peeling using 15% TCA.

Methotrexate Aspasomes Against Rheumatoid Arthritis: Optimized Hydrogel Loaded Liposomal Formulation with In Vivo Evaluation in Wistar Rats

Aspasomes of methotrexate with antioxidant, ascorbyl palmitate, were developed and optimized using factorial design by varying parameters such as lipid molar ratio, drug to lipid molar ratio, and type of hydration buffer for transdermal delivery for disease modifying activity in rheumatoid arthritis (RA). Aspasomes were characterized by drug-excipients interaction, particle size analysis, determination of zeta potential, entrapment efficiency, and surface properties. The best formulation was loaded into hydrogel for evaluation of in vitro drug release and tested in vivo against adjuvant induced arthritis model in wistar rats, by assessing various physiological, biochemical, hematological, and histopathological parameters. Optimized aspasome formulation exhibited smooth surface with particle size 386.8 nm, high drug loading (19.41%), negative surface potential, and controlled drug release in vitro over 24 h with a steady permeation rate. Transdermal application of methotrexate-loaded aspasome hydrogel for 12 days reduced rat paw diameter (21.25%), SGOT (40.43%), SGPT (54.75%), TNFα (33.99%), IL β (34.79%), cartilage damage (84.41%), inflammation (82.37%), panus formation (84.38%), and bone resorption (80.52%) as compared to arthritic control rats. Free methotrexate-treated group showed intermediate effects. However, drug-free aspasome treatment did not show any effect. The experimental results indicate a positive outcome in development of drug-loaded therapeutically active carrier system which presents a non-invasive controlled release transdermal formulation with good drug loading, drug permeation rate, and having better disease modifications against RA than the free drug, thereby providing a more attractive therapeutic strategy for rheumatoid disease management.

Process optimization and photostability of silymarin nanostructured lipid carriers: effect on UV-irradiated rat skin and SK-MEL 2 cell line

The objective of the present work was to formulate a novel stable delivery system which would not only overcome the solubility issue of silymarin, but also help to increase the therapeutic value by better permeation, anticancer action and reduced toxicity. This was envisaged through the recent developments in nanotechnology, combined with the activity of the phytoconstituent silymarin. A 2(3) full factorial design based on three independent variables was used for process optimization of nanostructured lipid carriers (NLC). Developed formulations were evaluated on the basis of particle size, morphology, in vitro drug release, photostability and cell line studies. Optimized silymarin-NLC was incorporated into carbopol gel and further assessed for rheological parameters. Stable behaviour in presence of light was proven by photostability testing of formulation. Permeability parameters were significantly higher in NLC as compared to marketed phytosome formulation. The NLC based gel described in this study showed faster onset, and prolonged activity up to 24 h and better action against edema as compared to marketed formulation. In case of anticancer activity of silymarin-NLC against SK-MEL 2 cell lines, silymarin-NLC proved to possess anticancer activity in a dose-dependent manner (10-80 μM) and induced apoptosis at 80 μM in SK-MEL 2 cancer cells. This work documents for the first time that silymarin can be formulated into nanostructured lipoidal carrier system for enhanced permeation, greater stability as well as anticancer activity for skin.

Enzymatic Production of Ascorbic Acid-2-phosphate by Recombinant Acid Phosphatase

In this study, an environmentally friendly and efficient enzymatic method for the synthesis of l-ascorbic acid-2-phosphate (AsA-2P) from l-ascorbic acid (AsA) was developed. The Pseudomonas aeruginosa acid phosphatase (PaAPase) was expressed in Escherichia coli BL21. The optimal temperature, optimal pH, K_m, k_cat, and catalytic efficiency of recombinant PaAPase were 50 °C, 5.0, 93 mM, 4.2 s^-1, and 2.7 mM^-1 min^-1, respectively. The maximal dry cell weight and PaAPase phosphorylating activity reached 8.5 g/L and 1127.7 U/L, respectively. The highest AsA-2P concentration (50.0 g/L) and the maximal conversion (39.2%) were obtained by incubating 75 g/L intact cells with 88 g/L AsA and 160 g/L sodium pyrophosphate under optimal conditions (0.1 mM Ca²⁺, pH 4.0, 30 °C) for 10 h; the average AsA-2P production rate was 5.0 g/L/h, and the AsA-2P production system was successfully scaled up to a 7.5 L fermenter. Therefore, the enzymatic process showed great potential for production of AsA-2P in industry.

Nanocurcumin Prevents Hypoxia Induced Stress in Primary Human Ventricular Cardiomyocytes by Maintaining Mitochondrial Homeostasis

Hypoxia induced oxidative stress incurs pathophysiological changes in hypertrophied cardiomyocytes by promoting translocation of p53 to mitochondria. Here, we investigate the cardio-protective efficacy of nanocurcumin in protecting primary human ventricular cardiomyocytes (HVCM) from hypoxia induced damages. Hypoxia induced hypertrophy was confirmed by FITC-phenylalanine uptake assay, atrial natriuretic factor (ANF) levels and cell size measurements. Hypoxia induced translocation of p53 was investigated by using mitochondrial membrane permeability transition pore blocker cyclosporin A (blocks entry of p53 to mitochondria) and confirmed by western blot and immunofluorescence. Mitochondrial damage in hypertrophied HVCM cells was evaluated by analysing bio-energetic, anti-oxidant and metabolic function and substrate switching form lipids to glucose. Nanocurcumin prevented translocation of p53 to mitochondria by stabilizing mitochondrial membrane potential and de-stressed hypertrophied HVCM cells by significant restoration in lactate, acetyl-coenzyme A, pyruvate and glucose content along with lactate dehydrogenase (LDH) and 5' adenosine monophosphate-activated protein kinase (AMPKα) activity. Significant restoration in glucose and modulation of GLUT-1 and GLUT-4 levels confirmed that nanocurcumin mediated prevention of substrate switching. Nanocurcumin prevented of mitochondrial stress as confirmed by c-fos/c-jun/p53 signalling. The data indicates decrease in p-300 histone acetyl transferase (HAT) mediated histone acetylation and GATA-4 activation as pharmacological targets of nanocurcumin in preventing hypoxia induced hypertrophy. The study provides an insight into propitious therapeutic effects of nanocurcumin in cardio-protection and usability in clinical applications.

Kinetics and Mechanism of Oxidation of L-Ascorbic Acid by Pt(IV)(aq) in Aqueous Hydrochloric Acid Medium

Reduction of [PtCl6]2− by L-ascorbic acid (H2ASc) in 0.1 M aqueous acid medium has been investigated spectrophotometrically under pseudo-first order condition at [PtCl6]2− = 0.005–0.007 mol dm−3, 0.05 ≤ [H2ASc]/mol dm−3 ≤ 0.3, 298 K ≤ T ≤ 308 K, [H+] = 0.14 mol dm−3, I=0.5 mol dm−3. The redox reaction follows the rate law: d[Pt(IV)]/dt = k[H2ASc][Pt(IV)], where k is the second-order rate constant and [H2ASc] is the total concentration of ascorbic acid. Electron transfer from [H2ASc] to Pt(IV) center leading to the release of two halide ions and formation of the reaction products, square planner Pt(II) halide complex, and dehydrated ascorbic acid is suggested. This redox reaction follows an outersphere mechanism as Pt(IV) complex is substituted inert. Activation parameters were calculated corresponding to rate of electron transfer reaction k. Activation parameters favor the electron transfer reaction.

Lipoidal soft hybrid biocarriers of supramolecular construction for drug delivery

Lipid-based innovations have achieved new heights during the last few years as an essential component of drug development. The current challenge of drug delivery is liberation of drug agents at the right time in a safe and reproducible manner to a specific target site. A number of novel drug delivery systems has emerged encompassing various routes of administration, to achieve controlled and targeted drug delivery. Microparticulate lipoidal vesicular system represents a unique technology platform suitable for the oral and systemic administration of a wide variety of molecules with important therapeutic biological activities, including drugs, genes, and vaccine antigens. The success of liposomes as drug carriers has been reflected in a number of liposome-based formulations, which are commercially available or are currently undergoing clinical trials. Also, novel lipid carrier-mediated vesicular systems are originated. This paper has focused on the lipid-based supramolecular vesicular carriers that are used in various drug delivery and drug targeting systems.

Lipoidal soft hybrid biocarriers of supramolecular construction for drug delivery

Lipid-based innovations have achieved new heights during the last few years as an essential component of drug development. The current challenge of drug delivery is liberation of drug agents at the right time in a safe and reproducible manner to a specific target site. A number of novel drug delivery systems has emerged encompassing various routes of administration, to achieve controlled and targeted drug delivery. Microparticulate lipoidal vesicular system represents a unique technology platform suitable for the oral and systemic administration of a wide variety of molecules with important therapeutic biological activities, including drugs, genes, and vaccine antigens. The success of liposomes as drug carriers has been reflected in a number of liposome-based formulations, which are commercially available or are currently undergoing clinical trials. Also, novel lipid carrier-mediated vesicular systems are originated. This paper has focused on the lipid-based supramolecular vesicular carriers that are used in various drug delivery and drug targeting systems.