Recent approaches and success of liposome-based nanodrug carriers for the treatment of brain tumor

: Brain tumors are nothing but a collection of neoplasms originated either from areas within the brain or from systemic metastasized tumors of other organs that have spread to the brain. It is a leading cause of death worldwide. The presence of the blood-brain barrier (BBB), blood-brain tumor barrier (BBTB), and some other factors may limit the entry of many potential therapeutics into the brain tissues in tumor area at the therapeutic concentration required for satisfying effectiveness. Liposomes are taking an active role in delivering many drugs through the BBB into the tumor due to their nanosize and their physiological compatibility. Further, this colloidal carrier can encapsulate both lipophilic and hydrophilic drugs due to its unique structure. The surface of the liposomes can be modified with various ligands that are very specific to the numerous receptors overexpressed onto the BBB as well as onto the diseased tumor surface site (i.e., BBTB) to deliver selective drugs into the tumor site. Moreover, the enhanced permeability and retention (EPR) effect can be an added advantage for nanosize liposomes to concentrate into the tumor microenvironment through relatively leaky vasculature of solid tumor in the brain where no restriction of penetration applies compared to normal BBB. Here in this review, we have tried to compilethe recent advancement along with the associated challenges of liposomes containing different anticancer chemotherapeutics across the BBB/BBTB for the treatment of gliomas that will be very helpful for the readers for better understanding of different trends of brain tumor targeted liposomes-based drug delivery and for pursuing fruitful research on the similar research domain.

Formulation and Toxicity Evaluation of Nanostructured Lipid Carriers for the Treatment of Acne

Background: Acne vulgarise is an inflammatory disease involving the pathological alteration of the sebaceous glands of the body. It is not a life-threatening disease but has a great influence on lifestyle. Topical combination therapy of vitamin A and antibacterial drugs is an effective treatment for acne. Materials and Methods: The current work investigates the nanostructure lipid colloidal carrier system of Tretinoin and Clindamycin phosphate. Nanostructured lipid carriers (NLCs) were prepared by highspeed homogenization-sonication technique and characterized for physicochemical properties, permeation, in vivo anti-acne and toxicity (acute 2000 mg/Kg, repeat 1000 mg/kg) in Wistar rats. Results: The prepared system was found to be stable, homogenous with more site retention of drugs having non-irritation and toxicity potential. The formulation showed a size of 283 nm, polydispersity index (PDI) 0.43 and Zeta potential (ZP) -37.9 mV with drug entrapment 92.0% and 66.15% for tretinoin and clindamycin respectively. Observed permeation was 18 % and 45% for Tretinoin and Clindamycin less than marketed formulation which is more focused on dermal retention of drug. No significant abnormalities and toxicological symptoms were observed for acute and repeat dose toxicity study for histopathology and haematological examinations of organs. Conclusion: Prepared NLC formulation was aimed at epidermal targeting. Based on obtained results it is concluded that developed lipid-based nanocarrier system of selected drugs showed the targeting potential for effective acne treatment.

Case studies of enhanced pharmacodynamic activity of poorly oral bioavailable drugs via solid lipid nanoparticles

Solid lipid nanoparticles (SLNs) considered as an alternative vehicle for the enhanced oral absorption of drugs, and also to enhance therapeutic effectiveness after oral administration. Pharmacodynamic activity of drug is mainly describes the pharmacological and therapeutic activity of drug to the biological system. Lipid nanoparticles especially SLNs made of physiological inert lipid molecules and helps the lymphatic transport. Numerous literatures is available on the effect of SLNs and other colloidal carrier systems on the pharmacokinetic activity of poorly bioavailable drugs, to improve their oral absorption and also respective mechanisms for the improved oral bioavailability. However, very few literatures is reported on the pharmacodynamic activity and the effect of dose on the pharmacodynamic activity. Therefore, the current review is mainly dealing with the effect of SLNs on the pharmacodynamic activity discussed. Keywords: Oral absorption, solid lipid nanoparticles, lymphatic transport, pharmacokinetics, pharmacodynamics.

Influence of Solid Lipid Nanoparticles on Pharmaco-dynamic Activity of Poorly Oral Bioavailable Drugs

In the recent scenario, lipid nanoparticles gain much attention on the oral absorption of drugs to enhance therapeutic effectiveness after oral administration. Pharmacodynamic activity of drug mainly describes the pharmacological and therapeutic activity of drug to the biological system. Lipid nanoparticles especially solid lipid nanoparticles are made of physiological inert lipid molecules and promotes the lymphatic transport. Abundant literature is available on the effect of lipid nanoparticles and other colloidal carrier systems on the pharmacokinetic parameters of poorly bioavailable drugs, to improve their oral absorption and also respective mechanisms for the improved oral bioavailability. However, little literature is reported on the pharmacodynamic activity and the effect of dose on the pharmacodynamic activity. It is of paramount importance to assess the influence of lipid nanoparticles on pharmacotherapeutic actions of specific drug classes. Therefore, current review is mainly focused on the role of solid lipid nanoparticles on the pharmacodynamic action and advantages of the developed delivery systems with respect to pharmacodynamic activity.

Influence of pH on the formation of organic and mineral colloïds and the associated release of various elements from surface sludge deposits of vertical flow constructed wetlands.

<p>In the treatment of raw domestic wastewaters in vertical flow constructed wetlands (VFCW), a sludge layer is formed at the surface of the first-stage filters by the retention of wastewater’s suspended solids. The deposits constituting this layer is now known to accumulate and degrade a large variety of contaminants during regular conditions of operation. The potential release of the contaminants from the sludge deposits under disturbed conditions or during off-site sludge reuse is therefore a major concern. This study investigated the influence of organic colloids on the mobilization of major and trace elements bound to VFCW surface sludge deposits.   </p><p>Although the role of organic and/or mineral colloidal carrier phases in the transport of elements in natural systems has been extensively studied, little is known in contrast on the production of colloidal carrier phases from anthropic materials and media such as the sludge deposits considered here.</p><p>The acid/base neutralizing capacity (environmental assessment procedure ANC/BNC) (CEN/TS 14429) was carried out to assess the release at different pHs. Samples of sludge deposits were contacted with solutions in a wide pH range and the suspensions filtered through 0.45 µm acetate cellulose filters were subsequently analyzed. In addition, the suspensions were also treated by ultrafiltration using successively membranes of decreasing pore size (30 kDa, 10 kDa and 3 kDa). The leached organic molecules were thereby divided into three groups: (i) large colloids (30 kDa-0.45 µm), (ii) small colloids (10 kDa-3 kDa) and (iii) truly dissolved fraction (< 3 kda). The permeates were analyzed for major and trace elements and organic particles. UV-vis spectra were also recorded to evaluate organic matter aromaticity.  </p><p>Results showed that the molecular weight of the organic matter released was pH-dependent. Under very acidic conditions, the release of dissolved and poorly aromatic organic matter was mostly observed. At natural pH, close to neutrality, the sludge deposits released mostly large organic colloids. At higher pHs, the release of larger organic colloids was observed associated with an increase in the aromaticity of organic molecules.</p><p>The major and trace mineral elements released were found in the different fractions analyzed, depending on  their affinity with the organic colloidal carrier phases described previously. A first group of elements (As, P, B, V, Na, K) were mostly found in solution, and therefore poorly affected by colloidal transport regardless of pH conditions.  A second group (Co, Cu, Ni, Cd, Zn) was found to be relatively uniformly distributed in the fractions associated with the large and small colloids as well as in the dissolved fraction. A third group (Cr, Ba, Mn, Ca, Li, Mg, Sr) was mostly associated to large organic and/or mineral colloids.  </p><p>The results obtained in this study are a contribution to a better description of colloidal production and the release of associated elements and contaminants from VFCW sludge deposits. This is a key issue in the assessment of environmental risks related to the operation of the treatment plants or the reuse of the sludge material.</p>

Nanoliposomes and Tocosomes as Multifunctional Nanocarriers for the Encapsulation of Nutraceutical and Dietary Molecules

Nanoscale lipid bilayers, or nanoliposomes, are generally spherical vesicles formed by the dispersion of phospholipid molecules in a water-based medium by energy input. The other nanoscale object discussed in this entry, i.e., tocosome, is a recently introduced bioactive carrier made mainly from tocopheryl phosphates. Due to their bi-compartmental structure, which consists of lipidic and aqueous compartments, these nanocarriers are capable of carrying hydrophilic and hydrophobic material separately or simultaneously. Nanoliposomes and tocosomes are able to provide protection and release of sensitive food-grade bioactive materials in a sustained manner. They are being utilized for the encapsulation of different types of bioactive materials (such as drugs, vaccines, antimicrobials, antioxidants, minerals and preservatives), for the enrichment and fortification of different food and nutraceutical formulations and manufacturing of functional products. However, a number of issues unique to the nutraceutical and food industry must first be resolved before these applications can completely become a reality. Considering the potentials and promises of these colloidal carrier systems, the present article reviews various aspects of nanoliposomes, in comparison with tocosomes, including the ingredients used in their manufacture, formation mechanisms and issues pertaining to their application in the formulation of health promoting dietary supplements and functional food products.

Lipid Nanoparticles and Active Natural Compounds: A Perfect Combination for Pharmaceutical Applications

Phytochemicals represent an important class of bioactive compounds characterized by significant health benefits. Notwithstanding these important features, their potential therapeutic properties suffer from poor water solubility and membrane permeability limiting their approach to nutraceutical and pharmaceutical applications. Lipid nanoparticles are well known carrier systems endowed with high biodegradation and an extraordinary biocompatible chemical nature, successfully used as platform for advanced delivery of many active compounds, including the oral, topical and systemic routes. This article is aimed at reviewing the last ten years of studies about the application of lipid nanoparticles in active natural compounds reporting examples and advantages of these colloidal carrier systems.