The role of high-resolution imaging in the evaluation of nanosystems for bioactive encapsulation and targeted nanotherapy

Lipid nanoparticle mediated small interfering RNA delivery as a potential therapy for Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative condition that exhibits a gradual decline in cognitive function and is prevalent among a significant number of individuals globally. The use of small interfering RNA (siRNA) molecules in RNA interference (RNAi) presents a promising therapeutic strategy for AD. Lipid nanoparticles (LNPs) have been developed as a delivery vehicle for siRNA, which can selectively suppress target genes, by enhancing cellular uptake and safeguarding siRNA from degradation. Numerous research studies have exhibited the effectiveness of LNP-mediated siRNA delivery in reducing amyloid beta (Aβ) levels and enhancing cognitive function in animal models of AD. The feasibility of employing LNP-mediated siRNA delivery as a therapeutic approach for AD is emphasized by the encouraging outcomes reported in clinical studies for other medical conditions. The use of LNP-mediated siRNA delivery has emerged as a promising strategy to slow down or even reverse the progression of AD by targeting the synthesis of tau phosphorylation and other genes linked to the condition. Improvement of the delivery mechanism and determination of the most suitable siRNA targets are crucial for the efficacious management of AD. This review focuses on the delivery of siRNA through LNPs as a promising therapeutic strategy for AD, based on the available literature.

Liposome vesicle cannot be formed in non-aqueous phase

In the February of 2023, Yang et al., report a paper to unreal mechanisms of protein and lipid oxidation in mayonnaise with claim of liposome formation in Mayonaise. As bilayer liposome has spherical or oval like structure composed bilayers separated by aqueous region, there is doubt for formation possibility of liposome in non-aqueous phase. In this bilayer vesicle a hydrophobic layer has been replaced between two outer and inner hydrophilic molecules, so regarding thermodynamic rules for tendency to a minimum enthalpy formation of bilayer vesicle with a hydrophobic outer layer in Mayonaise matrix is not possible. It seems more likely the micelle structure instead of liposome. The images in the article is indeed hard to see a liposomal bilayer structure. In other case, more explanation and evidences are required to clarify ambiguous points in this claim. So, arrangement of self-assembling of water soluble phospholipid may occur just in aqueous phase liposome formation is not possible. Also no document exists for bilayer of vesicles. So, those formed vesicle could be reverse micelle not liposome which usually form following dispersion of phospholipids in aqueous phase.

Biocompatible Nanomaterials in Food Science, Technology, and Nutrient Drug Delivery: Recent Developments and Applications

Nanomaterials exist as potential biocompatible materials in nature and are being synthesized to provide extraordinary characteristics in various food industry sectors. Synthesis of biocompatible nanomaterials requires modification in the shape, density, and size of nanomaterials. Biocompatible nanomaterials are synthesized to reduce toxicity, decrease adverse effects in the gastrointestinal tract, and enhance immune response. Nanomaterials can target organs and tissues. Nanomaterials are found to be effectively compatible by interacting with functional foods and nutraceuticals. Applications of these nanomaterials are novel strategies in food industries such as food safety, food processing, food quality, food packaging, and food labeling. Various functions like detection of toxins and pathogens; production of biocompatible packaging; enhancement in color, flavor, and aroma; processing edible film, and sensing authenticity of food product are being accomplished with no toxicity. This review provides a systematic study on the biocompatibility of nanomaterials. It highlights the synthesis of biocompatible nanomaterials and advanced functions of these nanomaterials in the production area, processing industry, safety improvement, quality control, edible packaging films, biocompatibility, current developments, legislations and regulations for Nano-products, health and safety concerns, toxicity and public perceptions for use of nanomaterials.

Advanced nanomedicine approaches applied for treatment of skin carcinoma

Skin-cancer is the commonest malignancy affecting huge proportion of the population, reaching heights in terms of morbidity. The treatment strategies are presently focusing on surgery, radiation and chemotherapy, which eventually cause destruction to unaffected cells. To overcome this limitation, wide range of nanoscaled materials have been recognized as potential carriers for delivering selective response to cancerous cells and neoplasms. Nanotechnological approach has been tremendously exploited in several areas, owing to their functional nanometric dimensions. The alarming incidence of skin cancer engenders burdensome effects worldwide, which is further awakening innovational medicinal approaches, accompanying target specific drug delivery tools for coveted benefits to provide reduced toxicity and tackle proliferative episodes of skin cancer. The developed nanosystems for anti-cancer agents include liposomes, ethosomes, nanofibers, solid lipid nanoparticles and metallic nanoparticles, which exhibit pronounced outcomes for skin carcinoma. In this review, skin cancer with its sub-types is explained in nutshell, followed by compendium of specific nanotechnological tools presented, in addition to therapeutic applications of drug-loaded nano systems for skin cancer.

Formulation of pH responsive multilamellar vesicles for targeted delivery of hydrophilic antibiotics

Fight against antimicrobial resistance calls for innovative strategies that can target infection sites and enhance activity of antibiotics. Herein is a pH responsive multilamellar vesicles (MLVs) for targeting bacterial infection sites. The vancomycin (VCM) loaded MLVs had 62.25 ± 8.7 nm, 0.15 ± 0.01 and -5.55 ± 2.76 mV size, PDI and zeta potential, respectively at pH 7.4. The MLVs had a negative ZP at pH 7.4 that switched to a positive charge and faster release of the drug at acidic pH. The encapsulation efficiency was found to be 46.34 ± 3.88 %. In silico studies of the lipids, interaction suggested an energetically stable system. Studies to determine the minimum inhibitory concentration studies (MIC) showed the MLVs had 2-times and 8-times MIC against Staphylococcus aureus (SA) and Methicillin resistance SA respectively at physiological pH. While at pH 6.0 there was 8 times reduction in MICs for the formulation against SA and MRSA in comparison to the bare drug. Fluorescence-activated Cell Sorting (FACS) studies demonstrated that even with 8-times lower MIC, MLVs had a similar elimination ability of MRSA cells when compared to the bare drug. Fluorescence microscopy showed MLVs had the ability to clear biofilms while the bare drug could not. Mice skin infection models studies showed that the colony finding units (CFUs) of MRSA recovered from groups treated with MLVs was 4,050 and 525-fold lower than the untreated and bare VCM treated groups, respectively. This study demonstrated pH-responsive multilamellar vesicles as effective system for targeting and enhancing antibacterial agents.

Protective Effects of Liposomal Curcumin on Oxidative Stress/Antioxidant Imbalance, Metalloproteinases 2 and -9, Histological Changes and Renal Function in Experimental Nephrotoxicity Induced by Gentamicin

BACKGROUND

Our study aimed to assess the efficiency of Curcumin nanoformulation (LCC) on experimental nephrotoxicity induced by Gentamicin in rats.

METHODS

Six groups of seven rats were used: C-(control group) received saline solution i.p. (i.p. = intraperitoneal), G-gentamicin (G, 80 mg/kg body weight (b.w.)), GCC1 and GCC2-with G and CC solution (single dose of 10 mg/kg b.w.-CC1, or 20 mg/kg b.w.-CC2), GLCC1 (10 mg/kg b.w.) and GLCC2 (20 mg/kg b.w.) with G and LCC administration. Oxidative stress parameters (NOx = nitric oxide, MDA = malondialdehyde, TOS = total oxidative stress), antioxidant parameters (CAT = catalase, TAC = total antioxidant capacity), matrix metalloproteinases (MMP-2 and MMP-9), and renal function parameters (creatinine, blood urea nitrogen, and urea) were measured. Kidneys histopathologic examination was made for each group.

RESULTS

Pretreatment with CC and LCC in both doses had significantly alleviating effects on assessed parameters (NOx, MDA, TOS, CAT, TAC, MMP-2, and -9) as compared with the untreated group (p < 0.006). Histopathological aspect and renal function were significantly improved in CC and LCC groups. Liposomal formulation (LCC) showed higher efficiency on all examined parameters compared to CC (p < 0.006).

CONCLUSIONS

Our results demonstrated improving renal function and kidney cytoarchitecture, oxidative stress/antioxidant/balance, and MMPs plasma concentrations with better dose-related efficacity of LCC than CC.

Nanoparticle-mediated approaches for Alzheimer's disease pathogenesis, diagnosis, and therapeutics

Alzheimer's disease (AD) is an irreversible and progressive neurodegenerative disorder manifested by memory loss and cognitive impairment. Deposition of the amyloid β plaques has been identified as the most common AD pathology; however, the excessive accumulation of phosphorylated or total tau proteins, reactive oxygen species, and higher acetylcholinesterase activity are also strongly associated with Alzheimer's dementia. Several therapeutic approaches targeting these pathogenic mechanisms have failed in clinical or preclinical trials, partly due to the limited bioavailability, poor cell, and blood-brain barrier penetration, and low drug half-life of current regimens. The nanoparticles (NPs)-mediated drug delivery systems improve drug solubility and bioavailability, thus renders as superior alternatives. Moreover, NPs-mediated approaches facilitate multiple drug loading and targeted drug delivery, thereby increasing drug efficacy. However, certain NPs can cause acute toxicity damaging cellular and tissue architecture, therefore, NP material should be carefully selected. In this review, we summarize the recent NPs-mediated studies that exploit various pathologic mechanisms of AD by labeling, identifying, and treating the affected brain pathologies. The disadvantages of the select NP-based deliveries and the future aspects will also be discussed.

Ultrasound-assisted preparation of different nanocarriers loaded with food bioactive ingredients

Developing green and facile approaches to produce nanostructures suitable for bioactives, nanoencapsulation faces some challenges in the nutraceutical and food bioactive industries due to potential risks arising from nanomaterials fabrication and consumption. High-intensity ultrasound is an effective technology to generate different bio-based structures in sub-micron or nanometer scale. This technique owing to some intrinsic advantages such as safety, straightforward operation, energy efficiency, and scale-up potential, as well as, ability to control over size and morpHology has stood out among various nanosynthetic routes. Ultrasonically-provided energy is mainly transferred to the droplets and particles via acoustic cavitation (which is formation, growth, and implosive collapse of bubbles in solvent). This review provides an outlook on the fundamentals of ultrasonication and some applicable setups in nanoencapsulation. Different kinds of nanostructures based on surfactants, lipids, proteins and carbohydrates formed by sonication, along with their advantages and disadvantages are assessed from the viewpoint of stability, particle size, and process impacts on some functionalities. The gastrointestinal fate and safety issues of ultrasonically prepared nanostructures are also discussed. Sonication, itself or in combination with other encapsulation approaches, alongside biopolymers generate nano-engineered carriers with enough stability, small particle sizes, and a low polydispersity. The nano-sized systems improve techno-functional activities of encapsulated bioactive agents including stability, solubility, dissolution, availability, controlled and targeted release profile in vitro and in vivo plus other bioactive properties such as antioxidant and antimicrobial capacities. Ultrasonically prepared nanocarriers show a great potential in fortifying food products with desired bioactive components, especially for the industrial applications.

In vitro and in vivo evaluation of colon cancer targeted epichlorohydrin crosslinked Portulaca-alginate beads

The aim of this study was to formulate a novel dual crosslinked hydrogel bead using Portulaca mucilage for colon-targeted delivery of 5-fluorouracil (5-FU) and evaluate its safety, specificity and efficacy. The ionotropic gelation technique was employed to prepare the hydrogel beads of Portulaca mucilage. For this, the mucilage was initially crosslinked with alginate and calcium ions. Epichlorohydrin was employed as a crosslinker in the second crosslinking step. The formulation was subjected to in vitro and in vivo studies to evaluate morphology, size, cytotoxicity, and organ distribution. Human HT-29 colon cancer cell-line was used for in vitro assays and in vivo studies were performed in Wistar rats to assess the usefulness and effectiveness of the formulation for colon cancer therapy. Microsphere sizes ranged from 930 to 977μm and possessed a high level of drug encapsulation efficiency (ca. 78% w/w). Compared with 5-FU solution (Tmax = 1.2 h, mean resident time: MRT = 3.3h) the dual crosslinked Portulaca microspheres exhibited sustained drug release after oral administration to rats (Tmax = 16h, MRT = 14h). The relative bioavailability of 5-FU solution and the microspheres were 100 and 93.6% respectively. Tissue distribution studies indicated high concentration of 5-FU in colon. In-vitro anticancer assay demonstrated IC50 value of 11.50 μg/ml against HT-29 colon cancer cell line. The epichlorohydrin cross-linked Portulaca microspheres prepared in this study provided sustained release of 5-FU up to 16h in the colonic region and enhanced the antitumor activity of the neoplastic drug. The formulation is hence an ideal carrier system for colon-targeted drug delivery.

Probing nanoliposomes using single particle analytical techniques: effect of excipients, solvents, phase transition and zeta potential

There has been a steady increase in the interest towards employing nanoliposomes as colloidal drug delivery systems, particularly in the last few years. Their biocompatibility nature along with the possibility of encapsulation of lipid-soluble, water-soluble and amphipathic molecules and compounds are among the advantages of employing these lipidic nanocarriers. A challenge in the successful formulation of nanoliposomal systems is to control the critical physicochemical properties, which impact their in vivo performance, and validating analytical techniques that can adequately characterize these nanostructures. Of particular interest are the chemical composition of nanoliposomes, their phase transition temperature, state of the encapsulated material, encapsulation efficiency, particle size distribution, morphology, internal structure, lamellarity, surface charge, and drug release pattern. These attributes are highly important in revealing the supramolecular arrangement of nanoliposomes and incorporated drugs and ensuring the stability of the formulation as well as consistent drug delivery to target tissues. In this article, we present characterization of nanoliposomal formulations as an example to illustrate identification of key in vitro characteristics of a typical nanotherapeutic agent. Corresponding analytical techniques are discussed within the context of nanoliposome assessment, single particle analysis and ensuring uniform manufacture of therapeutic formulations with batch-to-batch consistency.

Impact of Particle Size and Polydispersity Index on the Clinical Applications of Lipidic Nanocarrier Systems

Lipid-based drug delivery systems, or lipidic carriers, are being extensively employed to enhance the bioavailability of poorly-soluble drugs. They have the ability to incorporate both lipophilic and hydrophilic molecules and protecting them against degradation in vitro and in vivo. There is a number of physical attributes of lipid-based nanocarriers that determine their safety, stability, efficacy, as well as their in vitro and in vivo behaviour. These include average particle size/diameter and the polydispersity index (PDI), which is an indication of their quality with respect to the size distribution. The suitability of nanocarrier formulations for a particular route of drug administration depends on their average diameter, PDI and size stability, among other parameters. Controlling and validating these parameters are of key importance for the effective clinical applications of nanocarrier formulations. This review highlights the significance of size and PDI in the successful design, formulation and development of nanosystems for pharmaceutical, nutraceutical and other applications. Liposomes, nanoliposomes, vesicular phospholipid gels, solid lipid nanoparticles, transfersomes and tocosomes are presented as frequently-used lipidic drug carriers. The advantages and limitations of a range of available analytical techniques used to characterize lipidic nanocarrier formulations are also covered.

Chitosan films incorporated with nettle (Urtica Dioica L.) extract-loaded nanoliposomes: II. Antioxidant activity and release properties

Chitosan films were loaded with NE nettle (Urtica dioica L.) extract (NE) at concentrations of 0, 0.5, 1 and 1.5%w/w in the free or nanoliposomal form to obtain active and nanoactive films, respectively. The antioxidant potential of the films containing NE-loaded nanoliposomes was decreased in comparison of free NE incorporated films. Diffusion of NE to soybean oil was enough to delay the induction of the oxidation of soybean oil stored for 60 days in contact with chitosan based films. Release studies indicated that the release rate of NE in 95% ethanol simulant significantly decreased by the nanoencapsulation of NE. The diffusion coefficient (D) for chitosan films containing 1.5%w/w of free and encapsulated NE at 25 °C was 18.80 and 3.68 × 10^-7 cm² s^-1, respectively. Moreover, the formation of nanoliposomes diminished the increasing effect of temperature on the release rate as when storage temperature increased from 4 °C to 40 °C.

Nanotechnology: a future tool to improve quality and safety in meat industry

Nanotechnology refers to the new aspect of science modifies its physical, chemical and biological properties leading to new applications or enhanced utility. Keeping the pace with other industries, the meat industry has adopted the new technology in a range of applications to improve the quality and safety of products. The potential applications include the improvement in the tastes, texture, flavor, production of low fat and salt products, enhanced nutrient absorption, improved packaging techniques and better pathogen detection system. However some safety issues need to be addressed before taking a ride on the technology at the full throttle.

Overview of the role of nanotechnological innovations in the detection and treatment of solid tumors

Nanotechnology, although still in its infantile stages, has the potential to revolutionize the diagnosis, treatment, and monitoring of disease progression and success of therapy for numerous diseases and conditions, not least of which is cancer. As it is a leading cause of mortality worldwide, early cancer detection, as well as safe and efficacious therapeutic intervention, will be indispensable in improving the prognosis related to cancers and overall survival rate, as well as health-related quality of life of patients diagnosed with cancer. The development of a relatively new field of nanomedicine, which combines various domains and technologies including nanotechnology, medicine, biology, pharmacology, mathematics, physics, and chemistry, has yielded different approaches to addressing these challenges. Of particular relevance in cancer, nanosystems have shown appreciable success in the realm of diagnosis and treatment. Characteristics attributable to these systems on account of the nanoscale size range allow for individualization of therapy, passive targeting, the attachment of targeting moieties for more specific targeting, minimally invasive procedures, and real-time imaging and monitoring of in vivo processes. Furthermore, incorporation into nanosystems may have the potential to reintroduce into clinical practice drugs that are no longer used because of various shortfalls, as well as aid in the registration of new, potent drugs with suboptimal pharmacokinetic profiles. Research into the development of nanosystems for cancer diagnosis and therapy is thus a rapidly emerging and viable field of study.

The encapsulation of flavourzyme in nanoliposome by heating method

The main objective of this study was to use heating method (HM) to prepare liposome without employing any chemical solvent or detergent. Plackett-Burman design (PBD) was applied for the screening of significant process variables including the lecithin proportion, the cholesterol/lecithin ratio, the pH of solution for liposome preparation, the enzyme/lecithin ratio, the stirring time, the process temperature, the speed of stirrer, the ratio of stirrer to the tank diameter, the application of homogenization, the method of adding enzyme and centrifugation conditions on the encapsulation efficiency (EE %) of liposome and the activity of liposomal Flavourzyme (LAPU(-1)) (P < 0.05). Then, the response surface methodology based on the central composite design (CCD) was applied for the evaluation of the impacts of the significant mentioned variables on the EE (%) and the activity of the liposomal Flavourzyme. The results indicated that the lecithin proportion and the stirring time were the major influential variables for both responses. The most suitable formulation of the Flavourzyme-loaded liposome is 4.5 % lecithin, 45 °C temperature, 5 % Flavourzyme/lecithin ratio, 30 min stirring time and medium pH of 6. Under suitable operating conditions, the EE of liposome and the activity of the liposomal Flavourzyme were achieved as 26.5 % and 9.96 LAPU ml(-1), respectively. AFM technique and size distribution clearly showed the diameter of 189 nm for the spherical shape of the Flavourzyme- loaded nanoliposome.

The potent in vitro skin permeation of archaeosome made from lipids extracted of Sulfolobus acidocaldarius

Archaeosomes are a new generation of liposomes that exhibit higher stabilities under different conditions, such as high temperatures, alkaline or acidic pH, and presence of bile salts in comparison with liposomes, and can be used in biotechnology including drug, gene, and vaccine delivery. The objective of this study was to prepare archaeosomes using lipid extracted from Sulfolobus acidocaldarius and evaluate their physicochemical properties. The lipids were extracted from S. acidocaldarius and assayed by High Performance Thin-Layer Chromatography (HPTLC). Archaeosomes were prepared using film method and methylene blue was used as drug model. They were characterized for their vesicle size and Differential Scanning Calorimetry (DSC) was used to investigate changes in their thermal behavior. The released amount of methylene blue was determined using a dialysis membrane and rat skin. HPTLC analysis of the extracted lipids showed that glycerol ether may be the major lipid with more than 78 percent probability. Results of particle size determination showed a mean size of 158.33 nm and the results of DSC indicated the possible interaction of methylene blue with lipids during the preparation of archaeosome. The addition of cholesterol significantly improved the encapsulation of methylene blue in the archaeosome so that the encapsulation efficiency was 61.66 ± 2.88%. The result of in vitro skin permeation showed that methylene blue could pass through skin model according to Peppas model and there was about 41.66% release after 6 h, whereas no release was observed through dialysis membrane. According to the results of the study, it is concluded that archaeosome may be successfully used as drug delivery system.

Self-assembly of a peptide amphiphile containing L-carnosine and its mixtures with a multilamellar vesicle forming lipid

The self-assembly of the peptide amphiphile (PA) hexadecyl-(β-alanine-histidine) is examined in aqueous solution, along with its mixtures with multilamellar vesicles formed by DPPC (dipalmitoyl phosphatidylcholine). This PA, denoted C(16)-βAH, contains a dipeptide headgroup corresponding to the bioactive molecule L-carnosine. It is found to self-assemble into nanotapes based on stacked layers of molecules. Bilayers are found to coexist with monolayers in which the PA molecules pack with alternating up-down arrangement so that the headgroups decorate both surfaces. The bilayers become dehydrated as PA concentration increases and the number of layers in the stack decreases to produce ultrathin nanotapes comprised of 2-3 bilayers. Addition of the PA to DPPC multilamellar vesicles leads to a transition to well-defined unilamellar vesicles. The unique ability to modulate the stacking of this PA as a function of concentration, combined with its ability to induce a multilamellar to unilamellar thinning of DPPC vesicles, may be useful in biomaterials applications where the presentation of the peptide function at the surface of self-assembled nanostructures is crucial.

The applications of nanotechnology in food industry

Nanotechnology has the potential of application in the food industry and processing as new tools for pathogen detection, disease treatment delivery systems, food packaging, and delivery of bioactive compounds to target sites. The application of nanotechnology in food systems will provide new methods to improve safety and the nutritional value of food products. This article will review the current advances of applications of nanotechnology in food science and technology. Also, it describes new current food laws for nanofood and novel articles in the field of risk assessment of using nanotechnology in the food industry.

Nanomaterials: applications in cancer imaging and therapy

The application of nanomaterials (NMs) in biomedicine is increasing rapidly and offers excellent prospects for the development of new non-invasive strategies for the diagnosis and treatment of cancer. In this review, we provide a brief description of cancer pathology and the characteristics that are important for tumor-targeted NM design, followed by an overview of the different types of NMs explored to date, covering synthetic aspects and approaches explored for their application in unimodal and multimodal imaging, diagnosis and therapy. Significant synthetic advances now allow for the preparation of NMs with highly controlled geometry, surface charge, physicochemical properties, and the decoration of their surfaces with polymers and bioactive molecules in order to improve biocompatibility and to achieve active targeting. This is stimulating the development of a diverse range of nanometer-sized objects that can recognize cancer tissue, enabling visualization of tumors, delivery of anti-cancer drugs and/or the destruction of tumors by different therapeutic techniques.

Active food packaging evolution: transformation from micro- to nanotechnology

Predicting which attributes consumers are willing to pay extra for has become straightforward in recent years. The demands for the prime necessity of food of natural quality, elevated safety, minimally processed, ready-to-eat, and longer shelf-life have turned out to be matters of paramount importance. The increased awareness of environmental conservation and the escalating rate of foodborne illnesses have driven the food industry to implement a more innovative solution, i.e. bioactive packaging. Owing to nanotechnology application in eco-favorable coatings and encapsulation systems, the probabilities of enhancing food quality, safety, stability, and efficiency have been augmented. In this review article, the collective results highlight the food nanotechnology potentials with special focus on its application in active packaging, novel nano- and microencapsulation techniques, regulatory issues, and socio-ethical scepticism between nano-technophiles and nano-technophobes. No one has yet indicated the comparison of data concerning food nano- versus micro-technology; therefore noteworthy results of recent investigations are interpreted in the context of bioactive packaging. The next technological revolution in the domain of food science and nutrition would be the 3-BIOS concept enabling a controlled release of active agents through bioactive, biodegradable, and bionanocomposite combined strategy.

Role of nanocarrier systems in cancer nanotherapy

Cancer continues to be a major cause of morbidity and mortality worldwide. While discovery of new drugs and cancer chemotherapy opened a new era for the treatment of tumors, optimized concentration of drug at the target site is only possible at the expense of severe side effects. Nanoscale carrier systems have the potential to limit drug toxicity and achieve tumor localization. When linked with tumor-targeting moieties, such as tumor-specific ligands or monoclonal antibodies, the nanocarriers can be used to target cancer-specific receptors, tumor antigens, and tumor vasculatures with high affinity and precision. This article is an overview of advances and prospects in the applications of nanocarrier technology in cancer therapy. Applications of nanoliposomes, dendrimers, and nanoparticles in cancer therapy are explained, along with their preparation methods and targeting strategies.

Nanoliposomes: preparation and analysis

Nanoliposome, or submicron bilayer lipid vesicle, is a new technology for the encapsulation and delivery of bioactive agents. The list of bioactive material that can be incorporated to nanoliposomes is immense, ranging from pharmaceuticals to cosmetics and nutraceuticals. Because of their biocompatibility and biodegradability, along with their nanosize, nanoliposomes have potential applications in a vast range of fields, including nanotherapy (e.g. diagnosis, cancer therapy, gene delivery), cosmetics, food technology and agriculture. Nanoliposomes are able to enhance the performance of bioactive agents by improving their solubility and bioavailability, in vitro and in vivo stability, as well as preventing their unwanted interactions with other molecules. Another advantage of nanoliposomes is cell-specific targeting, which is a prerequisite to attain drug concentrations required for optimum therapeutic efficacy in the target site while minimising adverse effects on healthy cells and tissues. This chapter covers nanoliposomes, particularly with respect to their properties, preparation methods and analysis.

Effect of nanovesicle-encapsulated nisin on growth of Listeria monocytogenes in milk

Commercial nisin was encapsulated in nanovesicles (mean diameter 140 nm) prepared from partially purified soy lecithin. Nisin-loaded liposomes and unencapsulated (free) nisin were initially tested in BHI medium and skim milk inoculated with Listeria monocytogenes and incubated for 48 h at 30 degrees C. At such abuse temperature conditions, free nisin showed better inhibitory than the liposomal counterparts. Subsequently, the effect of encapsulated or free nisin was evaluated in combination with refrigeration (7 +/- 1 degrees C) in both whole (3.25% fat) and skim (0% fat) milk for up to 14 day. A decrease of 3-4 log cycles in L. monocytogenes counts was observed for free and encapsulated nisin at 0.5 mg/ml concentration. Liposome encapsulation of antimicrobial peptides may be important to overcome stability issues and interaction with food components. The utilization of nanovesicle-encapsulated nisin in combination with low temperatures appeared to be effective to control L. monocytogenes in milk, emphasizing the importance of hurdle technology to assure food safety.

Iontophoresis-driven penetration of nanovesicles through microneedle-induced skin microchannels for enhancing transdermal delivery of insulin

The transdsermal delivery of insulin remains a significant challenge due to low permeation rates at therapeutically useful rates. We report unilamellar nanovesicles with membrane thickness of 3-5 nm and entrapment efficiency of 89.05+/-0.91%, which can be driven by iontophoresis for enhancing transdermal delivery of insulin through microneedle-induced skin microchannels. The permeation rates of insulin from positive nanovesicles driven by iontophoresis through skins with microneedle-induced microchannels were 713.3 times higher than that of its passive diffusion. The in vivo studies show that the blood glucose levels of diabetic rats induced by the positive nanovesicles driven by iontophoresis through skins with microneedle-induced microchannels are 33.3% and 28.3% of the initial levels at 4 and 6 h, which are comparable to those induced by subcutaneous injection of insulin. The fluorescence imaging validated the penetration of insulin from the nanovesicles driven by iontophoresis through skins with microchannels. The nanovesicles with charges show significant permeation ability with the assistance of physical devices including microneedles and iontophoresis. This approach offers a new strategy for non-invasive delivery of peptides with large molecular weights using nanovesicles.