Liposomal delivery systems for anti-cancer analogues of vitamin E

Enhancing breast cancer treatment: Comprehensive study of gefitinib-loaded poloxamer 407/TPGS mixed micelles through design, development, in-silico modelling, In-Vitro testing, and Ex-Vivo characterization

Breast cancer continues to pose a substantial global health challenge, emphasizing the critical need for the advancement of novel therapeutic approaches. Key players in the regulation of apoptosis, a fundamental process in cell death, are the B-cell lymphoma 2 (Bcl-2) family proteins, namely Bcl-2 and Bax. These proteins have garnered attention as highly promising targets for the treatment of breast cancer. Targeting the overexpressed anti-apoptotic Bcl-2 protein in breast cancer, Gefitinib (GEF), an EGFR (Epidermal Growth Factor Receptor) inhibitor, emerges as a potential solution. This study focuses on designing Gefitinib-loaded polymeric mixed micelles (GPMM) using poloxamer 407 and TPGS (D-alpha tocopherol PEG1000 succinate) for breast cancer therapy. In silico analyses unveil strong interactions between GEF- Bcl-2 and TPGS-Pgp-2 receptors, indicating efficacy against breast cancer. Molecular dynamics simulations offer insights into GEF and TPGS interactions within the micelles. Formulation optimization via Design of Experiment ensures particle size and entrapment efficiency within acceptable ranges. Characterization tools such as zeta sizer, ATR-FTIR, XRD, TEM, AFM, NMR, TGA, and DSC confirms particle size, structure, functional groups, and thermodynamic events. The optimized micelles exhibit a particle size of 22.34 ± 0.18 nm, PDI of 0.038 ± 0.009, and zeta potential of -0.772 ± 0.12 mV. HPLC determines 95.67 ± 0.34% entrapment efficiency and 1.05 ± 0.12% drug loading capacity. In-vitro studies with MDA-MB-231 cell lines demonstrate enhanced cytotoxicity of GPMM compared to free GEF, suggesting its potential in breast cancer therapy. Cell cycle analysis reveals apoptosis induction through key apoptotic proteins. Western blot results confirm GPMM's ability to trigger apoptosis in MDA-MB-231 cells by activating caspase-3, Bax, Bcl-2, and Parp. In conclusion, these polymeric mixed micelles show promise in selectively targeting cancer cells, warranting future in-vivo studies for optimized clinical application against breast cancer.

Leaching of chemicals from microplastics: A review of chemical types, leaching mechanisms and influencing factors

It is widely known that microplastics are present everywhere and they pose certain risks to the ecosystem and humans which are partly attributed to the leaching of additives and chemicals from them. However, the leaching mechanisms remain insufficiently understood. This review paper aims to comprehensively and critically illustrate the leaching mechanisms in biotic and abiotic environments. It analyzes and synthesizes the factors influencing the leaching processes. It achieves the aims by reviewing >165 relevant scholarly papers published mainly in the past 10 years. According to this review, flame retardants, plasticizers and antioxidants are the three main groups of additives in microplastics with the potentials to disrupt endocrine functions, reproduction, brain development and kidney functions. Upon ingestion, the MPs are exposed to digestive fluids containing enzymes and acids which facilitate their degradation and leaching of chemicals. Fats and oils in the digestive tracts also aid the leaching and transport of these chemicals particularly the fat-soluble ones. Leaching is highly variable depending on chemical properties and bisphenols leach to a larger extent than other endocrine disrupting chemicals. However, the rates of leaching remain poorly understood, owing probably to multiple factors at play. Diffusion and partitioning are two main mechanisms of leaching in biotic and abiotic environments. Photodegradation is more predominant in the latter, generating reactive oxygen species which cause microplastic aging and leaching with minimal destruction of the chemicals leached. Effects of microplastic sizes on leaching are governed by Sherwood number, thickness of aqueous boundary layer and desorption half-life. This review contributes to better understanding of leaching of chemicals from microplastics which affect their ecotoxicities and human toxicity.

Nanocarrier of α-Tocopheryl Succinate Based on a Copolymer Derivative of (4,7-dichloroquinolin-2-yl)methanol and Its Cytotoxicity against a Breast Cancer Cell Line

In order to improve the water solubility and, therefore, bioavailability and therapeutic activity of anticancer hydrophobic drug α-tocopherol succinate (α-TOS), in this work, copolymers were synthesized via free radicals from QMES (1-[4,7-dichloroquinolin-2-ylmethyl]-4-methacryloyloxyethyl succinate) and VP (N-vinyl-2-pirrolidone) using different molar ratios, and were used to nanoencapsulate and deliver α-TOS into cancer cells MCF-7. QMES monomer was chosen because the QMES pendant group in the polymer tends to hydrolyze to form free 4,7-dichloro-2-quinolinemethanol (QOH), which also, like α-TOS, exhibit anti-proliferative effects on cancerous cells. From the QMES-VP 30:70 (QMES-30) and 40:60 (QMES-40) copolymers obtained, it was possible to prepare aqueous suspensions of empty nanoparticles (NPs) loaded with α-TOS by nanoprecipitation. The diameter and encapsulation efficiency (%EE) of the QMES-30 NPs loaded with α-TOS were 128.6 nm and 52%; while for the QMES-40 NPs loaded with α-TOS, they were 148.8 nm and 65%. The results of the AlamarBlue assay at 72 h of treatment show that empty QMES-30 NPs (without α-TOS) produced a marked cytotoxic effect on MCF-7 breast cancer cells, corresponding to an IC50 value of 0.043 mg mL-1, and importantly, they did not exhibit cytotoxicity against healthy HUVEC cells. Furthermore, NP-QMES-40 loaded with α-TOS were cytotoxic with an IC50 value of 0.076 mg mL-1, demonstrating a progressive release of α-TOS; however, the latter nanoparticles were also cytotoxic to healthy cells in the range of the assayed concentrations. These results contribute to the search for a new polymeric nanocarrier of QOH, α-TOS or other hydrophobic drugs for the treatment of cancer or others diseases treatable with these drugs.

Cellular Membrane-Engineered Nanovesicles as a Three-Stage Booster to Target the Lesion Core

The lesion core is the area with the most serious injury and vigorous repair. Existing nanocarriers are difficult to break through the targeted delivery to the lesion core for precise treatment in the intracellular and extracellular microenvironment. Herein, a cellular membrane-engineered nanovesicle (CMEV) with a hierarchical structure is constructed using the double emulsion-extrusion method by integrating a neutrophil membrane, functional antibody, and gelled drug-loaded core as a three-stage booster to target the lesion core and deliver catestatin (CST), a small therapeutic peptide, for ischemic cardiomyopathy therapy. By coating the neutrophil membrane outside the shell, CMEV is endowed with the function of neutrophil-like migration to achieve the first stage of tissue targeting. Based on the specific anchoring to injured myocardium, a myosin light chain 3 (MLC3) antibody is embedded to fulfill the second stage of CMEV accumulation in the lesion core. The gelled core containing CST-sodium alginate (NaAlg) with a pH-responsive shell is prepared by ionic cross-linking to accomplish the third stage of precise CST administration. Triggered by the microenvironment, NaAlg electrostatically adheres to the lesion core for sustained release, enhancing the efficacy of CST in improving cardiomyocyte apoptosis, excessive fibrosis, macrophage polarization, and angiogenesis. Thus, the "three-stage booster" nanovesicle significantly ameliorates cardiac function and adverse remodeling to treat ischemic cardiomyopathy.

Recent Advances in Doxorubicin Formulation to Enhance Pharmacokinetics and Tumor Targeting

Doxorubicin (DOX), a widely used drug in cancer chemotherapy, induces cell death via multiple intracellular interactions, generating reactive oxygen species and DNA-adducted configurations that induce apoptosis, topoisomerase II inhibition, and histone eviction. Despite its wide therapeutic efficacy in solid tumors, DOX often induces drug resistance and cardiotoxicity. It shows limited intestinal absorption because of low paracellular permeability and P-glycoprotein (P-gp)-mediated efflux. We reviewed various parenteral DOX formulations, such as liposomes, polymeric micelles, polymeric nanoparticles, and polymer-drug conjugates, under clinical use or trials to increase its therapeutic efficacy. To improve the bioavailability of DOX in intravenous and oral cancer treatment, studies have proposed a pH- or redox-sensitive and receptor-targeted system for overcoming DOX resistance and increasing therapeutic efficacy without causing DOX-induced toxicity. Multifunctional formulations of DOX with mucoadhesiveness and increased intestinal permeability through tight-junction modulation and P-gp inhibition have also been used as orally bioavailable DOX in the preclinical stage. The increasing trends of developing oral formulations from intravenous formulations, the application of mucoadhesive technology, permeation-enhancing technology, and pharmacokinetic modulation with functional excipients might facilitate the further development of oral DOX.

TPGS Decorated Liposomes as Multifunctional Nano-Delivery Systems

Liposomes are sphere-shaped vesicles that can capture therapeutics either in the outer phospholipid bilayer or inner aqueous core. Liposomes, especially when surface-modified with functional materials, have been used to achieve many benefits in drug delivery, including improving drug solubility, oral bioavailability, pharmacokinetics, and delivery to disease target sites such as cancers. Among the functional materials used to modify the surface of liposomes, the FDA-approved non-ionic surfactant D-alpha-tocopheryl polyethylene glycol succinate (TPGS) is increasingly being applied due to its biocompatibility, lack of toxicity, applicability to various administration routes and ability to enhance solubilization, stability, penetration and overall pharmacokinetics. TPGS decorated liposomes are emerging as a promising drug delivery system for various diseases and are expected to enter the market in the coming years. In this review article, we focus on the multifunctional properties of TPGS-coated liposomes and their beneficial therapeutic applications, including for oral drug delivery, vaccine delivery, ocular administration, and the treatment of various cancers. We also suggest future directions to optimise the manufacture and performance of TPGS liposomes and, thus, the delivery and effect of encapsulated diagnostics and therapeutics.

A Review of Bioactive Compounds and Antioxidant Activity Properties of Piper Species

Antioxidants are compounds that are able to inhibit the negative effects that come from free radicals. The phenomenon of imbalanced antioxidant production and the accumulation of free radicals in cells and tissues can cause oxidative stress. Excessive free radicals that enter the body cannot be warded off by endogenous antioxidant compounds so that the required antioxidant compounds can come from the outside, which helps in the performance of endogenous antioxidants. Antioxidants that come from outside consist of synthetic and natural antioxidants; however, synthetic antioxidants are not an option because they have toxic and carcinogenic effects. Therefore, the use of natural ingredients is an alternative method that is needed to create a new natural antioxidant compound. Piper species are being considered as possible medicinal plants for the development of new sources of antioxidants. Several studies have been carried out starting from the extract levels, fractions, and compounds of the Piper species, which showed good antioxidant activity. Currently, some of these plants are being used as ingredients in traditional medicines to treat allergies, toothaches, and coughs. This review examines the distribution, botanical data, pharmacology, especially antioxidant activity, and the compounds contained in five Piper species, namely Piper amalago L., Piper betle L., Piper hispidum Sw., Piper longum L., and Piper umbellatum L.

Development of a novel tocopheryl ester for suppression of lipid accumulation without cytotoxicity by optimization of dicarboxylic ester moiety

Tocopheryl succinate (Tsuc) is a succinic acid ester of the well-known antioxidant α-tocopherol (T). Tsuc exhibits various biological activities, including tumor growth suppression via activation of cell signaling and prevention of lipid accumulation in mouse adipocyte 3T3-L1 cells. The latter findings suggest that Tsuc may be a drug candidate for the treatment of obesity. However, Tsuc was found to induce apoptosis of normal cells (in addition to cancer cells), demonstrating the need to reduce the cytotoxicity of Tsuc without losing the suppression effect on lipid accumulation. Based on our previous findings, we focused on the ester structure of Tsuc for controlling cytotoxicity. Herein, we examined the cytotoxicity and lipid accumulation suppression effect of various T ester derivatives. We found that the terminal carboxylic group is necessary for suppression of lipid accumulation. We synthesized tocopheryl glutarate (Tglu) and tocopheryl adipate (Tadi) by elongation of carbon atoms 1 and 2 of the dicarboxylic moiety, respectively. Tglu and Tadi did not show any cytotoxicity, and both esters suppressed lipid accumulation, although their suppression activities were weaker than that of Tsuc. Tadi showed a more potent lipid accumulation inhibitory effect than Tglu. Although Tadi inhibited lipogenesis and promoted lipolysis, lipolysis was induced at lower concentrations than inhibition of lipogenesis, suggesting that Tadi mainly affects lipolysis. Taken together, we succeeded in the reduction of cytotoxicity, without loss of the suppression effect on lipid accumulation, by elongation of the dicarboxylic moiety of Tsuc. Tadi may be a promising candidate as an anti-obesity drug.

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Successful development of a novel tocopheryl ester as an anti-obesity drug candidate.

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Reduction of cytotoxicity by elongation of dicarboxylic moiety of tocopheryl esters.

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A novel tocopheryl ester mainly induces lipolysis of accumulated lipids.

Skin cancer, including related pathways and therapy and the role of luteolin derivatives as potential therapeutics

Cutaneous malignant melanoma is the fastest growing and the most aggressive form of skin cancer that is diagnosed. However, its incidence is relatively scarce compared to the highest mortality rate of all skin cancers. The much more common skin cancers include nonmelanoma malignant skin cancers. Moreover, over the past several decades, the frequency of all skin cancers has increased much more dynamically than that of almost any other type of cancer. Among the available therapeutic options for skin cancers, chemotherapy used immediately after the surgical intervention has been an essential element. Unfortunately, the main problem with conventional chemopreventive regimens involves the lack of response to treatment and the associated side effects. Hence, there is a need for much more effective anticancer drugs. Correspondingly, the targeted alternatives have involved phytochemicals, which are safer chemotherapeutic agents and exhibit competitive anticancer activity with high therapeutic efficacy. Among polyphenolic compounds, some flavonoids and their derivatives, which are mostly found in medicinal plants, have been demonstrated to influence the modulation of signaling pathways at each stage of the carcinogenesis process, which is also important in the context of skin cancers. Hence, this review focuses on an exhaustive overview of the therapeutic effects of luteolin and its derivatives in the treatment and prevention of skin cancers. The bioavailability and structure–activity relationships of luteolin derivatives are also discussed. This review is the first such complete account of all of the scientific reports concerning this particular group of natural compounds that target a specific area of neoplastic diseases.

Fat-Soluble Vitamin Supplementation Using Liposomes, Cyclodextrins, or Medium-Chain Triglycerides in Cystic Fibrosis: A Randomized Controlled Trial

Fat-soluble vitamin deficiency remains a challenge in cystic fibrosis (CF), chronic pancreatitis, and biliary atresia. Liposomes and cyclodextrins can enhance their bioavailability, thus this multi-center randomized placebo-controlled trial compared three-month supplementation of fat-soluble vitamins in the form of liposomes or cyclodextrins to medium-chain triglycerides (MCT) in pancreatic-insufficient CF patients. The daily doses were as follows: 2000 IU of retinyl palmitate, 4000 IU of vitamin D3, 200 IU of RRR-α-tocopherol, and 200 µg of vitamin K2 as menaquinone-7, with vitamin E given in soybean oil instead of liposomes. All participants received 4 mg of β-carotene and 1.07 mg of vitamin K1 to ensure compliance with the guidelines. The primary outcome was the change from the baseline of all-trans-retinol and 25-hydroxyvitamin D3 concentrations and the percentage of undercarboxylated osteocalcin. Out of 75 randomized patients (n = 28 liposomes, n = 22 cyclodextrins, and n = 25 MCT), 67 completed the trial (89%; n = 26 liposomes, n = 18 cyclodextrins, and n = 23 MCT) and had a median age of 22 years (IQR 19–28), body mass index of 20.6 kg/m² [18.4–22.0], and forced expiratory volume in 1 s of 65% (44–84%). The liposomal formulation of vitamin A was associated with the improved evolution of serum all-trans-retinol compared to the control (median +1.7 ng/mL (IQR −44.3–86.1) vs. −38.8 ng/mL (−71.2–6.8), p = 0.028). Cyclodextrins enhanced the bioavailability of vitamin D3 (+9.0 ng/mL (1.0–17.0) vs. +3.0 ng/mL (−4.0–7.0), p = 0.012) and vitamin E (+4.34 µg/mL (0.33–6.52) vs. −0.34 µg/mL (−1.71–2.15), p = 0.010). Liposomes may augment the bioavailability of vitamin A and cyclodextrins may strengthen the supplementation of vitamins D3 and E relative to MCT in pancreatic-insufficient CF but further studies are required to assess liposomal vitamin E (German Clinical Trial Register number DRKS00014295, funded from EU and Norsa Pharma).

Synthesis and antioxidant activity of the inulin derivative bearing 1,2,3-triazole and diphenyl phosphate

In this paper, the inulin derivative (3) bearing 1,2,3-triazole and diphenyl phosphate was successfully synthesized by CuAAC Click chemistry. Detailed structural characterization was determined using FTIR spectroscopy, ¹H NMR spectroscopy, ¹³C NMR spectroscopy, and elemental analysis. The antioxidant activities against hydroxyl radicals, superoxide radicals, and DPPH radicals were estimated in vitro respectively. The results showed that the antioxidant activity of the inulin derivative (3) was significantly enhanced compared with inulin. The inulin derivative (3) exhibited stronger radical scavenging abilities, especially against hydroxyl radicals and superoxide radicals. The scavenging values of the inulin derivative (3) were 98.2% and 95.4% at 1.6 mg/mL against hydroxyl radicals and superoxide radicals respectively. Besides, the scavenging value of the inulin derivative (3) increased by about 40% to scavenge DPPH radicals at 1.6 mg/mL than inulin. The results showed that the inulin derivative (3) bearing 1,2,3-triazole and diphenyl phosphate exhibited tremendously enhanced antioxidant activity compared with inulin. The synthetic strategy might provide an effective way to prepare novel inulin antioxidant biomaterials.

Vitamin E succinate with multiple functions: A versatile agent in nanomedicine-based cancer therapy and its delivery strategies

Vitamin E succinate (VES), a succinic acid ester of vitamin E, is one of the most effective anticancer compounds of the vitamin E family. VES can inhibit tumor growth by multiple pathways mainly involve tumor proliferation inhibition, apoptosis induction, and metastasis prevention. More importantly, the mitochondrial targeting and damaging property of VES endows it with great potential in exhibiting synergetic effect with conventional chemotherapeutic drugs and overcoming multidrug resistance (MDR). Given the lipophilicity of VES that hinders its bioavailability and therapeutic activity, nanotechnology with multiple advantages has been widely explored to deliver VES and opened up new avenues for its in vivo application. This review aims to introduce the anticancer mechanisms of VES and summarize its delivery strategies using nano-drug delivery systems. Specifically, VES-based combination therapy for synergetic anticancer effect, MDR-reversal, and oral chemotherapy improvement are highlighted. Finally, the challenges and perspectives are discussed.

The pH-Induced Specific Area Changes of Unsaturated Lipids Deposited onto a Bubble Interface

In this work, we used an original experimental setup to examine the behavior of insoluble monolayers made with pH-sensitive lipids. Two kinds of unsaturated lipids were chosen: a cationic one (lipid 1) bearing an ammonium headgroup and an anionic one (lipid 2) terminated with an acidic phenol group. The lipids were deposited onto an air bubble interface maintained in an aqueous phase and, after stabilization, were subjected to a series of compressions performed at different pH values. These experiments disclosed a gradual increase in the specific area per molecule when lipids were neutralized. Imposing a pH variation at constant bubble volume also provided surface pressure profiles that confirmed this molecular behavior. As complementary characterization, dilatational rheology disclosed a phase transition from a purely elastic monophasic system to a viscoelastic two-phase system. We hypothesized that this unexpected increase in the specific area with lipid neutralization is related to the presence of unsaturations in each of the two branches of the hydrophobic tails that induce disorder, thereby increasing the molecular area at the interface. Application of the two-dimensional Volmer equation of state allowed the generation of quantitative values for the specific areas that showed variations with pH. It also allowed the determination of apparent pK_a values, which are affected by both the electrostatic potential within the monolayer and the affinity of the lipid polar head for the aqueous phase.

Poly(ester-thioether) microspheres co-loaded with erlotinib and α-tocopheryl succinate for combinational therapy of non-small cell lung cancer

Polymer microspheres are attracting wide attention in localized cancer therapy owing to the excellent biocompatibility and drug loading capacity, controllable biodegradation speeds, and minimized systemic toxicity. Herein, we presented poly(ester-thioether) microspheres, porous and nonporous, as drug depots for localized therapy of non-small cell lung cancer (NSCLC). Specifically, erlotinib and α-tocopheryl succinate (α-TOS), which are respectively an epidermal growth factor receptor (EGFR) inhibitor and mitochondria destabilizer, were efficiently loaded into porous and nonporous poly(ester-thioether) microspheres for the treatment of EGFR-overexpressing NSCLC (A549 cells). The poly(ester-thioether) microspheres significantly improved the bioavailability of both erlotinib and α-TOS in comparison to the free drug combination, realizing synergistic inhibition of A549 cells both in vitro and in vivo. The porous microspheres displayed faster degradation and drug release than the nonporous counterpart, thereby showing better anticancer efficacy. Overall, our study reported a new anticancer strategy of erlotinib and α-TOS combination for therapy of NSCLC, and established that poly(ester-thioether) microspheres could be a robust and biodegradable reservoir for drug delivery and localized cancer therapy.

Mitochondria-Targeted Antioxidants: A Step towards Disease Treatment

Mitochondria are the main organelles that produce adenosine 5′-triphosphate (ATP) and reactive oxygen species (ROS) in eukaryotic cells and meanwhile susceptible to oxidative damage. The irreversible oxidative damage in mitochondria has been implicated in various human diseases. Increasing evidence indicates the therapeutic potential of mitochondria-targeted antioxidants (MTAs) for oxidative damage-associated diseases. In this article, we introduce the advantageous properties of MTAs compared with the conventional (nontargeted) ones, review different mitochondria-targeted delivery systems and antioxidants, and summarize their experimental results for various disease treatments in different animal models and clinical trials. The combined evidence demonstrates that mitochondrial redox homeostasis is a potential target for disease treatment. Meanwhile, the limitations and prospects for exploiting MTAs are discussed, which might pave ways for further trial design and drug development.

Cancer cell metabolism: Rewiring the mitochondrial hub

To adapt to tumoral environment conditions or even to escape chemotherapy, cells rapidly reprogram their metabolism to handle adversities and survive. Given the rapid rise of studies uncovering novel insights and therapeutic opportunities based on the role of mitochondria in tumor metabolic programing and therapeutics, this review summarizes most significant developments in the field. Taking in mind the key role of mitochondria on carcinogenesis and tumor progression due to their involvement on tumor plasticity, metabolic remodeling, and signaling re-wiring, those organelles are also potential therapeutic targets. Among other topics, we address the recent data intersecting mitochondria as of prognostic value and staging in cancer, by mitochondrial DNA (mtDNA) determination, and current inhibitors developments targeting mtDNA, OXPHOS machinery and metabolic pathways. We contribute for a holistic view of the role of mitochondria metabolism and directed therapeutics to understand tumor metabolism, to circumvent therapy resistance, and to control tumor development.

Tocopheryl Succinate-Induced Structural Changes in DPPC Liposomes: DSC and ANS Fluorescence Studies

Recent studies show that alpha-tocopheryl succinate (TS) exhibits selective toxicity against cancer cells. In this study, we investigated the effect of TS's presence on the physico-chemical and structural properties of DPPC liposomes using fluorescence parameters (intensity, lifetime, and position of emission maximum) of 1-anilino-8-naphtalene sulphonate (ANS), differential scanning calorimetry (DSC) and zeta potential methods. Increasing the TS presence in the DPPC gel phase produced ANS fluorescence enhancement with a hypsochromic shift of the maximum. The zeta potential measurements show an increase in the negative surface charge and confirmed that this process is connected with the hydrophobic properties of dye, which becomes located deeper into the interphase region with a progressing membrane disorder. Temperature dependence studies showed that an increase in temperature increases the ANS fluorescence and shifts the ANS maximum emission from 464 to 475 nm indicating a shift from hydrophobic to a more aqueous environment. In the liquid crystalline phase, the quenching of ANS fluorescence occurs due to the increased accessibility of water to the ANS located in the glycerol region. The DSC results revealed that increasing the presence of TS led to the formation of multicomponent DSC traces, indicating the formation of intermediate structures during melting. The present results confirmed that TS embedded into the DPPC membrane led to its disruption due to destabilisation of its structure, which confirmed the measured biophysical parameters of the membrane.

Antioxidants and antioxidant methods: an updated overview

Antioxidants had a growing interest owing to their protective roles in food and pharmaceutical products against oxidative deterioration and in the body and against oxidative stress-mediated pathological processes. Screening of antioxidant properties of plants and plant-derived compounds requires appropriate methods, which address the mechanism of antioxidant activity and focus on the kinetics of the reactions including the antioxidants. Many studies evaluating the antioxidant activity of various samples of research interest using different methods in food and human health have been conducted. These methods are classified, described, and discussed in this review. Methods based on inhibited autoxidation are the most suited for termination-enhancing antioxidants and for chain-breaking antioxidants, while different specific studies are needed for preventive antioxidants. For this purpose, the most common methods used in vitro determination of antioxidant capacity of food constituents were examined. Also, a selection of chemical testing methods was critically reviewed and highlighted. In addition, their advantages, disadvantages, limitations and usefulness were discussed and investigated for pure molecules and raw extracts. The effect and influence of the reaction medium on the performance of antioxidants are also addressed. Hence, this overview provides a basis and rationale for developing standardized antioxidant methods for the food, nutraceuticals, and dietary supplement industries. In addition, the most important advantages and shortcomings of each method were detected and highlighted. The chemical principles of these methods are outlined and critically discussed. The chemical principles of methods of 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulphonate) radical (ABTS^·+) scavenging, 1,1-diphenyl-2-picrylhydrazyl (DPPH·) radical scavenging, Fe³⁺-Fe²⁺ transformation assay, ferric reducing antioxidant power (FRAP) assay, cupric ions (Cu²⁺) reducing power assay (Cuprac), Folin-Ciocalteu reducing capacity (FCR assay), peroxyl radical (ROO·), superoxide radical anion (O₂^·-), hydrogen peroxide (H₂O₂) scavenging assay, hydroxyl radical (OH·) scavenging assay, singlet oxygen (¹O₂) quenching assay, nitric oxide radical (NO·) scavenging assay and chemiluminescence assay are outlined and critically discussed. Also, the general antioxidant aspects of main food components were discussed by a number of methods, which are currently used for the detection of antioxidant properties of food components. This review consists of two main sections. The first section is devoted to the main components in the food and pharmaceutical applications. The second general section comprises some definitions of the main antioxidant methods commonly used for the determination of the antioxidant activity of components. In addition, some chemical, mechanistic and kinetic basis, and technical details of the used methods are given.

Mixed Oleic Acid-Erucic Acid Liposomes as a Carrier for Anticancer Drugs

BACKGROUND

Liposomes are mostly known to be prepared from phospholipids and lipids and have a remarkable capacity to encapsulate both lipophobic and lipophilic molecules. However, there is little research on developing fatty acid liposomes for chemotherapy.

OBJECTIVE

We have successfully prepared mixed fatty acid liposomes from two monounsaturated fatty acids, namely oleic acid and erucic acid, which stabilised by DOPEPEG2000. The Critical Vesicular Concentration (CVC) of liposomes was found to be within 0.09 to 0.21 mmol dm^-3, with an average particle size of 400 nm.

METHODS

Encapsulation of various anticancer drugs such as folinic acid, methotrexate, doxorubicin, or irinotecan resulted in Encapsulation Efficiency (%EE) of up to 90%. Using a 3-(4, 5-dimethylthiazol-2- yl)-2,5-diphenyltetrazolium bromide (MTT) assay, the median Inhibitory Concentration (IC₅₀) values of mixed oleic acid-erucic acid encapsulating hydrophilic drugs was remarkably reduced at the end of 24 hours of incubation with the human lung carcinoma cell line A549.

RESULTS

The results suggest that mixed oleic acid-erucic acid liposomes are a potential new approach to further develop as an alternative vehicle of various drugs for cancer treatment.

Antioxidants in Cancer Therapy: Recent Trends in Application of Nanotechnology for Enhanced Delivery

Recently, the occurrence of cancer has significantly increased; it represents the second-most frequent cause of death after cardiovascular diseases. Many dietary antioxidants have shown large impact as effective agents for cancer prevention by reducing oxidative stress, which has been a part in the development of many diseases, including cancer. One of the obstacles in the delivery of antioxidant therapies into the required domain lies in the inadequate delivery of these agents to their intended site of action. Using nanotechnology in delivery of antioxidants leads to increased therapeutic index and higher drug concentration in tumor tissues, thus enhancing anticancer treatment. In this review, we discuss the role of different antioxidants in cancer therapy and their improved therapeutic effect through their formulation using nanotechnology.

Prolonged retention of liposomes in the pleural cavity of normal mice and high tumor distribution in mice with malignant pleural effusion, after intrapleural injection

Background: Intrapleural administration of compounds is a lung targeted, innovative therapeutic strategy for mesothelioma, which can be refined as a route for drug delivery that minimizes the potential for systemic toxicity. However, little is currently known about the retention of liposomal drugs at the site, after such topical administration. Purpose: To evaluate the retention of liposomes in lungs following intrapleural injection, and how this might be modulated by liposome properties and disease progression. Methods: DiR-incorporating liposomes with various lipid compositions and sizes were prepared, characterized (for size distribution and zeta potential) and injected intrapleurally in normal mice and mice with malignant pleural effusion (MPE). DiR retention in pleural cavity was followed by biofluorescence imaging. Results: Experimental results demonstrate that liposome size and PEG-coating, have a significant effect on residence time in the pleural cavity; negative surface charge does not. More than 20% liposomal-DiR is retained 24 d post-injection (in some cases), indicating the high potential towards localized diseases. Ex-vivo liposomal-DiR signal in tumors of MPE mice was similar to signal in liver, suggesting high tumor targeting potential of intrapleurally injected liposomes. Finally, no difference was noticed in liposomal-DiR retention between tumor-inoculated (MPE) and healthy mice, indicating the stability of liposomes in the presence of effusion (in MPE mice). Conclusion: The current study provides novel insights for using liposomes by intrapleural administration for the treatment of lung diseases.

Preparation and Evaluation of Liposomes Co-Loaded with Doxorubicin, Phospholipase D Inhibitor 5-Fluoro-2-Indolyl Deschlorohalopemide (FIPI) and D-Alpha Tocopheryl Acid Succinate (α-TOS) for Anti-Metastasis

Tumor metastasis has become a key obstacle to cancer treatment, which causes high mortality. Nowadays, it involves multiple complex pathways, and conventional treatments are not effective due to fewer targets. The aims of the present study were to construct a novel liposome delivery system co-loading a specific PLD inhibitor 5-fluoro-2-indolyldes-chlorohalopemide (FIPI) in combination with antitumor drug doxorubicin (DOX) and functional excipient D-alpha tocopheryl acid succinate (α-TOS) for anti-metastasis. In this study, the liposomes containing three components (DFT-Lip) with different physicochemical properties were successfully prepared by film dispersion method combined with pH-gradient method. Physicochemical parameters such as particles size, potential, encapsulation efficiency, stability, and release profiles were investigated. In vitro and in vivo anti-metastasis effectiveness against highly metastatic breast cancer MDA-MB-231 cell line was evaluated. The liposomes showed uniform particle size (approximately 119 nm), high drug encapsulation efficiency (> 90%), slow release characteristics and stability. In vitro anti-tumor cell metastasis study demonstrated DFT-Lip could greatly inhibit motility, migration and invasion of MDA-MB-231 cells compared to other liposomes, predicting a synergistic anti-tumor metastasis effect between FIPI with α-TOS in liposomes. In vivo anti-metastasis study showed that DFT-Lip prevented the initiation and the progression of metastasis of high metastatic breast cancer. These results suggested that the liposomes containing DOX, FIPI, and α-TOS might be a promising strategy for metastatic tumor therapy in clinics.

Contribution of Molecular Structure to Self-Assembling and Biological Properties of Bifunctional Lipid-Like 4-(N-Alkylpyridinium)-1,4-Dihydropyridines

The design of nanoparticle delivery materials possessing biological activities is an attractive strategy for the development of various therapies. In this study, 11 cationic amphiphilic 4-(N-alkylpyridinium)-1,4-dihydropyridine (1,4-DHP) derivatives differing in alkyl chain length and propargyl moiety/ties number and position were selected for the study of their self-assembling properties, evaluation of their cytotoxicity in vitro and toxicity on microorganisms, and the characterisation of their interaction with phospholipids. These lipid-like 1,4-DHPs have been earlier proposed as promising nanocarriers for DNA delivery. We have revealed that the mean diameter of freshly prepared nanoparticles varied from 58 to 513 nm, depending upon the 4-(N-alkylpyridinium)-1,4-DHP structure. Additionally, we have confirmed that only nanoparticles formed by 4-(N-dodecylpyridinium)-1,4-DHP derivatives 3 and 6, and by 4-(N-hexadecylpyridinium)-1,4-DHP derivatives 10 and 11 were stable after two weeks of storage. The nanoparticles of these compounds were found to be homogenous in size distribution, ranging from 124 to 221 nm. The polydispersity index (PDI) values of 1,4-DHPs samples 3, 6, 10, and 11 were in the range of 0.10 to 0.37. We also demonstrated that the nanoparticles formed by 4-(N-dodecylpyridinium)-1,4-DHP derivatives 3, 6, and 9, and 4-(N-hexadecylpyridinium)-1,4-DHP derivatives 10 and 11 had zeta-potentials from +26.07 mV (compound 6) to +62.80 mV (compound 11), indicating a strongly positive surface charge and confirming the relative electrostatic stability of these nanoparticle solutions. Transmission electron microscopy (TEM) images of nanoaggregates formed by 1,4-DHPs 3 and 11 confirmed liposome-like structures with diameters around 70 to 170 nm. The critical aggregation concentration (CAC) value interval for 4-(N-alkylpyridinium)-1,4-DHP was from 7.6 µM (compound 11) to 43.3 µM (compound 6). The tested 4-(N-alkylpyridinium)-1,4-DHP derivatives were able to quench the fluorescence of the binary 1,6-diphenyl-1,3,5-hexatriene (DPH)—1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) system, demonstrating hydrophobic interactions of 1,4-DHPs with phospholipids. Thus, 4-(N-dodecylpyridinium)-1,4-DHP derivative 3 quenched the fluorescence of the DPH–DPPC system more efficiently than the other 4-(N-alkylpyridinium)-1,4-DHP derivatives. Likewise the compound 3, also 4-(N-dodecylpyridinium)-1,4-DHP derivative 9 interacted with the phospholipids. Moreover, we have established that increasing the length of the alkyl chain at the quaternised nitrogen of the 4-(N-alkylpyridinium)-1,4-DHP molecule or the introduction of propargyl moieties in the 1,4-DHP molecule significantly influences the cytotoxicity on HT-1080 (human fibrosarcoma) and MH-22A (mouse hepatocarcinoma) cell lines, as well as the estimated basal cytotoxicity. Additionally, it was demonstrated that the toxicity of the 4-(N-alkylpyridinium)-1,4-DHP derivatives on the Gram-positive and Gram-negative bacteria species and eukaryotic microorganism depended on the presence of the alkyl chain length at the N-alkyl pyridinium moiety, as well as the number of propargyl groups. These lipid-like compounds may be proposed for the further development of drug formulations to be used in cancer treatment.

Delivery of docetaxel using pH-sensitive liposomes based on D-α-tocopheryl poly(2-ethyl-2-oxazoline) succinate: Comparison with PEGylated liposomes

This study aimed to investigate the ability of the novel materials D-α-tocopheryl poly(2-ethyl-2-oxazoline) succinate (TPOS) to construct pH-sensitive liposomes. TPOS was initially synthesized and characterized by TLC, FTIR, and ¹H-NMR. The buffering capacity of polyethylene glycol- distearoyl phosphatidylethanolamine (PEG-DSPE) and TPOS was determined by acid-base titration, and TPOS displayed a slower downtrend and gentler slope of titration curve than PEG-DSPE within pH 7.4–5.0. Studies on the in vitro drug release demonstrated that TPOS modified docetaxel (DOC) liposomes (TPOS-DOC-L) had a slower drug-release rate at pH 7.4 similar to PEGylated-DOC liposomes (PEG-DOC-L), whereas the release rate reached approximately 86.92% ± 1.69% at pH 6.4. In vitro cellular uptake assays by microplate reader, and flow cytometry revealed that TPOS modified coumarin 6 liposomes (TPOS-C6-L) had stronger cellular uptake at pH 6.4 than that at pH 7.4 (P < 0.01). Conversely, for PEGylated C6 liposomes (PEG-C6-L) and conventional C6 liposomes (C6-L), very similar cellular uptakes were exhibited at different pH values. Confocal laser scanning microscopy images showed that PEG-C6-L and C6-L were mainly located in lysosomes. By contrast, TPOS-C6-L showed broader cytoplasmic release and distribution at 4 h. MTT assay showed that the cytotoxicity of TPOS-DOC-L was similar to that of PEG-DOC-L and conventional DOC liposomes (DOC-L) at the same DOC concentration and at pH 7.4, but was much lower than those at pH 6.4 after 48 h of incubation. The apoptosis of PEG-DOC-L and DOC-L had no remarkable improvement with decreased pH from 7.4 to 6.4. Meanwhile, TPOS-DOC-L significantly induced the apoptosis of HeLa cells with decreased pH. Therefore, TPOS can be a biomaterial for the construction of a pH-sensitive drug delivery system.

A Nanomicellar Prodrug Carrier Based on Ibuprofen-Conjugated Polymer for Co-delivery of Doxorubicin

Ibuprofen (IBU) is a non-steroidal anti-inflammatory drug (NSAID), which is widely used to reduce fever and treat inflammation and acute pain. Recently, its application in cancer treatment is also being explored. In this work, we synthesized a well-defined IBU-based amphiphilic diblock copolymer via reversible addition fragmentation transfer (RAFT) polymerization of IBU-based vinyl monomer. The amphiphilic copolymer POEG-b-PVBIBU (denoted as POVI) was composed of a hydrophilic poly(oligo(ethylene glycol)) block and a hydrophobic IBU-bearing prodrug block, which was able to self-assemble into prodrug nanomicelles. In addition, it could serve as a carrier to co-load other drugs including doxorubicin (DOX), paclitaxel (PTX), and docetaxel (DTX). By using DOX as a model anti-cancer drug, the delivery function of POVI carrier, including the drug release, in vitro cytotoxicity, cellular uptake, and in vivo antitumor activity, was evaluated. DOX-loaded POVI micelles exhibited sustained release of DOX. Besides, DOX/POVI micelles were effectively taken up by tumor cells with an efficiency comparable to that of free DOX. Moreover, in vivo studies showed that POVI carrier itself had modest antitumor activity. After loading DOX, the antitumor activity was significantly increased, which was significantly higher than that of free DOX. Our results suggest that POVI polymer represents a simple and effective dual-functional carrier for co-delivery of IBU and DOX to improve the anticancer activity.

Nanodesign of new self-assembling core-shell gellan-transfersomes loading baicalin and in vivo evaluation of repair response in skin

Gellan nanohydrogel and phospholipid vesicles were combined to incorporate baicalin in new self-assembling core-shell gellan-transfersomes obtained by an easy, scalable method. The vesicles were small in size (~107 nm) and monodispersed (P.I. ≤ 0.24), forming a viscous system (~24 mPa/s) as compared to transfersomes (~1.6 mPa/s), as confirmed by rheological studies. Gellan was anchored to the bilayer domains through cholesterol, and the polymer chains were distributed onto the outer surface of the bilayer, thus forming a core-shell structure, as suggested by SAXS analyses. The optimal carrier ability of core-shell gellan-transfersomes was established by the high deposition of baicalin in the skin (~11% in the whole skin), especially in the deeper tissue (~8% in the dermis). Moreover, their ability to improve baicalin efficacy in anti-inflammatory and skin repair tests was confirmed in vivo in mice, providing the complete skin restoration and inhibiting all the studied inflammatory markers.

Liposome encapsulated luteolin showed enhanced antitumor efficacy to colorectal carcinoma

Luteolin is a falconoid compound that is present in various types of plants and possesses remarkable potential as a chemopreventive agent. However, the poor aqueous solubility of luteolin limits its clinical application. In the present study, an approach towards chemoprevention was explored using liposomes to deliver luteolin, and the antitumor efficacy was investigated in colorectal carcinoma. The present findings demonstrated that luteolin was efficiently encapsulated into liposomes with an encapsulation efficiency as high as 90%. The particle size of the liposomal luteolin (Lipo-Lut) and ζ-potential were optimized. In vitro studies demonstrated that, Lipo-Lut had a significant inhibitory effect on the growth on the CT26 colorectal carcinoma cell line compared with free luteolin (Free-Lut). The in vivo study indicated that Lipo-Lut could achieve superior antitumor effects against CT26 tumor compared with luteolin alone. The present results suggested that liposome delivery of luteolin improved solubility, bioavailability and may have potential applications in chemoprevention in clinical settings.

A nanoliposome-based photoactivable drug delivery system for enhanced cancer therapy and overcoming treatment resistance

Recently, stimuli-responsive drug delivery systems (DDSs) with high spatial/temporal resolution bring many benefits to cancer treatment. However, cancer cells always develop ways to resist and evade treatment, ultimately limit the treatment efficacy of the DDSs. Here, we introduce photo-activated nanoliposomes (PNLs) that impart light-induced cytotoxicity and reversal of drug resistance in synchrony with a photoinitiated and rapid release of antitumor drug. The PNLs consist of a nanoliposome doped with a photosensitizer (hematoporphyrin monomethyl ether [HMME]) in the lipid bilayer and an antitumor drug doxorubicin (DOX) encapsulated inside. PNLs have several distinctive capabilities: 1) carrying high loadings of DOX and HMME and releasing the payloads in a photo-cleavage manner with high spatial/temporal resolution at the site of actions via photocatalysis; 2) reducing drug efflux in MCF-7/multidrug resistance cells via decreasing the level of P-glycoprotein induced by photodynamic therapy (PDT); 3) accumulating in tumor site taking advantage of the enhanced permeability and retention effect; and 4) combining effective chemotherapy and PDT to exert much enhanced anticancer effect and achieving significant tumor regression in a drug-resistant tumor model with little side effects.

Evaluation of mesoporous silica nanoparticles for oral drug delivery - current status and perspective of MSNs drug carriers

The oral pathway is considered as the most common method for drug administration, although many drugs, especially the highly pH- and/or enzymatic biodegradable peptide drugs, are very difficult to formulate and achieve a good intestinal absorption. Efficient systematic absorption of an active substance, delivered via oral ingestion, is only achievable if the drug (1) is substantially present as a solution in the gastrointestinal tract, (2) is able to penetrate through the intestinal mucus, (3) overcomes the different gastrointestinal barriers, and (4) provides an effective therapeutic dose. Therefore, optimization of oral bioavailability of poorly-soluble drugs still remains a significant challenge for the pharmaceutical industry. Even though numerous conventional drug carriers have successfully solved some of the issues related to oral delivery of poorly-soluble drugs, only few of them met commercialization requirements. These drawbacks have led the scientific world to reconsider its approaches toward targeted drug delivery systems and researchers started looking for alternative vectorized carriers. In this area, nanoparticle-based materials have several significant advantages over free and non-formulated drugs. For example, nanosized porous silica carriers allow for more sustained and controlled drug release or improved oral bioavailability. Thus, in the present review, we will highlight the most important features of nanostructured silica drug carriers, such as particle size, particle shape, surface roughness or surface functionalization, and underline the key advantages of these nanosupports. In particular, this article will discuss recent progress and challenges in the area of mesoporous silica nanocarriers used for oral drug delivery. Additional emphasis will be set on the biological and chemical features of the gastrointestinal tract as well as currently tested nanoformulations and strategies to avoid drug degradation in the gastrointestinal environment.

Multifunctional decoration of alpha-tocopheryl succinate-based NP for cancer treatment: effect of TPP and LTVSPWY peptide

Active targeting not only of a specific cell but also a specific organelle maximizes the therapeutic activity minimizing adverse side effects in healthy tissues. The present work describes the synthesis, characterization, and in vitro biological activity of active targeting nanoparticles (NP) for cancer therapy based on α-tocopheryl succinate (α-TOS), a well-known mitocan, that selectively induces apoptosis of cancer cells and proliferalting endothelial cells. Human epidermal growth factor receptor 2 (HER2) targeting peptide LTVSPWY (PEP) and triphenylphosphonium lipophilic cation (TPP) were conjugated to a previously optimized RAFT block copolymer that formed self-assembled NP of appropriate size for this application and low polydispersity by self-organized precipitation method. PEP and TPP were included in order to target not only HER2 positive cancer cells, but also the mitochondria of these cancer cells, respectively. The in vitro experiments demonstrated the faster incorporation of the active-targeting NP and the higher accumulation of TPP-bearing NP in the mitochondria of MDA-MB-453 HER2 positive cancer cells compared to non-decorated NP. Moreover, the encapsulation of additional α-TOS in the hydrophobic core of the NP was achieved with high efficiencies. The loaded NP presented higher cytotoxicity than unloaded NP but preserved their selectivity against cancer cells in a range of tested concentrations.

Co-delivery nanocarriers targeting folate receptor and encapsulating 2-deoxyglucose and α-tocopheryl succinate enhance anti-tumor effect in vivo

A combination administration of chemical agents was highlighted to treat tumors. Recently, tumor cell has been found to be different from normal cell in metabolic manner. Most of cancer cells prefer aerobic glycolysis to mitochondrial oxidative phosphorylation (OXPHOS) to satisfy energy and biomass synthesis requirement to survive, grow and proliferate, which provides novel and potential therapeutic targets for chemotherapy. Here, 2-deoxy-d-glucose (2-DG), a potent inhibitor of glucose metabolism, was used to inhibit glycolysis of tumor cells; α-tocopheryl succinate (α-TOS), a water-insoluble vitamin E derivative, was chosen to suppress OXPHOS. Our data demonstrated that the combination treatment of 2-DG and α-TOS could significantly promote the anti-tumor efficiency in vitro compared with administration of the single drug. In order to maximize therapeutic activity and minimize negative side effects, a co-delivery nanocarrier targeting folate receptor (FR) was developed to encapsulate 2-DG and α-TOS simultaneously based on our previous work. Transmission electron microscope, dynamic light scattering method and UV-visible spectrophotometers were used to investigate morphology, size distribution and loading efficiency of the α-TOS-2-DG-loaded and FR-targeted nanoparticles (TDF NPs). The TDF NPs were found to possess a layer-by-layer shape, and the dynamic size was <100 nm. The final encapsulation efficiencies of α-TOS and 2-DG in TDF NPs were 94.3%±1.3% and 61.7%±7.7% with respect to drug-loading capacities of 8.9%±0.8% and 13.2%±2.6%, respectively. Almost no α-TOS release was found within 80 h, and release of 2-DG was sustained and slow within 72 h. The results of FR binding assay and fluorescence biodistribution revealed that TDF NPs could target FR highly expressed on tumor cell in vitro and in vivo. Further, in vivo anti-tumor experiments showed that TDF NPs had an improved biological function with less toxicity. Thus, our work indicates that the co-delivery TDF NPs have a great potential in tumor therapy.

Tocotrienols: the unsaturated sidekick shifting new paradigms in vitamin E therapeutics

Vitamin E family members: tocotrienols and tocopherols are widely known for their health benefits. Decades of research on tocotrienols have shown they have diverse biological activities such as antioxidant, anti-inflammatory, anticancer, neuroprotective and skin protection benefits, as well as improved cognition, bone health, longevity and reduction of cholesterol levels in plasma. Tocotrienols also modulate several intracellular molecular targets and, most importantly, have been shown to improve lipid profiles, reduce total cholesterol and reduce the volume of white matter lesions in human clinical trials. This review provides a comprehensive update on the little-known therapeutic potentials of tocotrienols, which tocopherols lack in a variety of inflammation-driven diseases.

Toxicity evaluation of methoxy poly(ethylene oxide)-block-poly(ε-caprolactone) polymeric micelles following multiple oral and intraperitoneal administration to rats

Methoxy poly(ethylene oxide)-block-poly(ɛ-caprolactone) (PEO-b-PCL) copolymers are amphiphilic and biodegradable copolymers designed to deliver a variety of drugs and diagnostic agents. The aim of this study was to synthesize PEO-b-PCL block copolymers and assess the toxic effects of drug-free PEO-b-PCL micelles after multiple-dose administrations via oral or intraperitoneal (ip) administration in rats. Assembly of block copolymers was achieved by co-solvent evaporation method. To investigate the toxicity profile of PEO-b-PCL micelles, sixty animals were divided into two major groups: The first group received PEO-b-PCL micelles (100 mg/kg) by oral gavage daily for seven days, while the other group received the same dose of micelles by ip injections daily for seven days. Twenty-four hours following the last dose, half of the animals from each group were sacrificed and blood and organs (lung, liver, kidneys, heart and spleen) were collected. Remaining animals were observed for further 14 days and was sacrificed at the end of the third week, and blood and organs were collected. None of the polymeric micelles administered caused any significant effects on relative organ weight, animal body weight, leucocytes count, % lymphocytes, liver and kidney toxicity markers and organs histology. Although the dose of copolymers used in this study is much higher than those used for drug delivery, it did not cause any significant toxic effects in rats. Histological examination of all the organs confirmed the nontoxic nature of the micelles.

Enhanced Bioactivity of α-Tocopheryl Succinate Based Block Copolymer Nanoparticles by Reduced Hydrophobicity

Well-structured amphiphilic copolymers are necessary to obtain self-assembled nanoparticles (NPs) based on synthetic polymers. Highly homogeneous and monodispersed macromolecules obtained by controlled polymerization have successfully been used for this purpose. However, disaggregation of the organized macromolecules is desired when a bioactive element, such as α-tocopheryl succinate, is introduced in self-assembled NPs and this element must be exposed or released to exert its action. The aim of this work is to demonstrate that the bioactivity of synthetic NPs based on defined reversible addition-fragmentation chain transfer polymerization copolymers can be enhanced by the introduction of hydrophilic comonomers in the hydrophobic segment. The amphiphilic terpolymers are based on poly(ethylene glycol) (PEG) as hydrophilic block, and a hydrophobic block based on a methacrylic derivative of α-tocopheryl succinate (MTOS) and small amounts of 2-hydroxyethyl methacrylate (HEMA) (PEG-b-poly(MTOS-co-HEMA)). The introduction of HEMA reduces hydrophobicity and introduces "disorder" both in the homogeneous blocks and the compact core of the corresponding NPs. These NPs are able to encapsulate additional α-tocopheryl succinate (α-TOS) with high efficiency and their biological activity is much higher than that described for the unmodified copolymers, proposedly due to more efficient degradation and release of α-TOS, demonstrating the importance of the hydrophilic-hydrophobic balance.

Mitochondrially Targeted Nanoparticles Based on α-TOS for the Selective Cancer Treatment

The aim of this work is the preparation of an active nanovehicle for the effective administration of α-tocopheryl succinate (α-TOS). α-TOS is loaded in the core of nanoparticles (NPs) based on amphiphilic pseudo-block copolymers of N-vinyl pyrrolidone and a methacrylic derivative of α-TOS. These well-defined spherical NPs have sizes below 165 nm and high encapsulation efficiencies. In vitro activity of NPs is tested in hypopharynx squamous carcinoma (FaDu) cells and nonmalignant epithelial cells, demonstrating that the presence of additional α-TOS significantly enhances its antiproliferative activity; however, a range of selective concentrations is observed. These NPs induce apoptosis of FaDu cells by activating the mitochondria death pathway (via caspase-9). Both loaded and unloaded NPs act via complex II and produce high levels of reactive oxygen species that trigger apoptosis. Additionally, these NPs effectively suppress the vascular endothelial growth factor (VEGF) expression of human umbilical vein endothelial cells (HUVECs). These results open the possibility to use this promising nanoformulation as an α-TOS delivery system for the effective cancer treatment, effectively resolving the current limitations of free α-TOS administration.

Enhanced antioxidation via encapsulation of isooctyl p-methoxycinnamate with sodium deoxycholate-mediated liposome endocytosis

Isooctyl p-methoxycinnamate(OMC) is a commonly used chemical ultraviolet B sunscreen that suffers rapid degradation with current delivery systems following sun exposure. In this study, deoxycholate-mediated liposome (DOC-LS) endocytosis was employed to improve the antioxidation effects of OMC following topical administration, and the in vitro cell uptake was investigated to understand the enhanced cutaneous absorption of the drug via this nanocarrier. Following topical application, structural changes in the stratum corneum were identified. With the increase of DOC content, the drug deposition in skin decreased; from this, a DOC-LS formulation was selected that showed significantly more drug delivery in skin than did the other preparations (P<0.05). DOC-LS decreased skin resistance, suggesting its ability to induce skin barrier disruption. In vitro HaCaT keratinocyte cell uptake of coumarin-6 incorporated in the two types of phosphatidylcholine (PC) vesicles (i.e., LS or DOC-LS) yielded similar fluorescence intensities following incubation for different periods (P<0.05). However, CCC-ESF-1 embryonic fibroblast cell uptake of the fluorescence revealed time-dependence, and the emitted light from DOC-LS incubated cells was stronger than that from cells incubated with LS (P<0.05). These findings might be associated with the endocytic pathway of HaCaT, which mainly exhibited adsorption or physical adhesion of the fluorescent vesicles, whereas CCC-ESF-1 markedly internalized the PC vesicles via the lysosomes, as shown by intracellular fluorescence co-location studies. Following loading with the same amount of OMC, the DOC-LS vesicles exhibited superior skin tissue antioxidative capacity among the preparations tested, corroborating the in vivo skin drug deposition results. Thus, our results suggest that DOC-LS is a promising system for OMC dermal delivery without promoting skin irritation, which is quite advantageous for therapeutic purposes.

Reducing the cytotoxicity while improving the anti-cancer activity of silver nanoparticles through α-tocopherol succinate modification

α-TOS modified Ag NPs could reduce the cytotoxicity while improving the anti-cancer activity of Ag NPs.