Lipid Liposomes Research Articles

Detection of Bacterial Rhamnolipid Toxin by Redox Liposome Single Impact Electrochemistry.

The detection of Rhamnolipid virulence factor produced by Pseudomonas aeruginosa involved in nosocomial infections is reported by using the redox liposome single impact electrochemistry. Redox liposomes based on 1,2-dimyristoyl-sn-glycero-3-phosphocholine as a pure phospholipid and potassium ferrocyanide as an encapsulated redox content are designed for using the interaction of the target toxin with the lipid membrane as a sensing strategy. The electrochemical sensing principle is based on the weakening of the liposomes lipid membrane upon interaction with Rhamnolipid toxin which leads upon impact at an ultramicroelectrode to the breakdown of the liposomes and the release/electrolysis of its encapsulated redox probe. We present as a proof of concept the sensitive and fast sensing of a submicromolar concentration of Rhamnolipid which is detected after less than 30 minutes of incubation with the liposomes, by the appearing of current spikes in the chronoamperometry measurement.

Synthesis and Evaluation of High Functionality and Quality Cell-penetrating Peptide Conjugated Lipid for Octaarginine Modified PEGylated Liposomes In U251 and U87 Glioma Cells

The use of peptide ligand modified PEGylated liposomes has been widely investigated for tumor targeting. Peptides are mainly inserted in the liposomal lipid bilayer using PEG2K-lipid spacer (Peptide-PEG2K-DSPE). However, a lower cellular uptake from longer nonlinear PEG2K spacer was reported, we here synthesized a high functionality and quality (HFQ) lipid with a short, linear serine-glycine repeated peptide [(SG)5] spacer. The objective of the current study is to develop novel octaarginine (R8) peptide-HFQ lipid grafted PEGylated liposomes for glioma cells targeting. In vitro liposomes characterization showed that the mean particle size of all liposomal formulations was in the nano-scale range < 120 nm, with a small PDI value (i.e. ∼0.2) and had a spherical shape under Transmission Electron Microscope, indicating a homogenous particle size distribution. The flow cytometry in vitro cellular association data with U251 MG and U87 cells revealed that 1.5% R8-(SG)5-lipid-PEGylated liposomes exhibited significantly higher cellular association of ∼15.87 and 7.59-fold than the conventional R8-PEG2K-lipid-PEGylated liposomes (10.4 and 6.19-fold), respectively, relative to the unmodified PEGylated liposomes. Moreover, intracellular distribution studies using confocal laser scanning microscopy (CLSM) corroborated the results of the in vitro cell association. The use of ligand-HFQ-lipid liposomes could be a potential alternative to ligand-PEG2K-lipid-modified liposomes as a drug delivery system for tumor targeting.

Nano-Drug Delivery Systems: Possible End to the Rising Threats of Tuberculosis.

Tuberculosis (TB) is still one of the deadliest disease across the globe caused by Mycobacterium tuberculosis (Mtb). Mtb invades host macrophages and other immune cells, modifies their lysosome trafficking proteins, prevents phagolysosomes formation, and inhibits the TNF receptor-dependent apoptosis in macrophages and monocytes. Tuberculosis (TB) killed 1.4 million people worldwide in the year 2019. Despite the advancements in tuberculosis (TB) treatments, multidrugresistant tuberculosis (MDR-TB) remains a severe threat to human health. The complications are further compounded by the emergence of MDR/XDR strains and the failure of conventional drug regimens to eradicate the resistant bacterial strains. Thus, new therapeutic approaches aim to ensure cure without relapse, to prevent the occurrence of deaths and emergence of drug-resistant strains. In this context, this review article summarises the essential nanotechnology-related research outcomes in the treatment of tuberculosis (TB), including drug-susceptible and drug-resistant strains of Mtb. The novel anti-tuberculosis drug delivery systems are also being detailed. This article highlights recent advances in tuberculosis (TB) treatments, including the use of novel drug delivery technologies such as solid lipid nanoparticles, liposomes, polymeric micelles, nano-suspensions, nano-emulsion, niosomes, liposomes, polymeric nanoparticles and microparticles for the delivery of anti-TB drugs and hence eradication and control of both drug-susceptible as well as drug-resistant strains of Mtb.

Delivery of synthetic mRNAs for tissue regeneration.

In recent years, nucleic acid-based therapeutics have gained increasing importance as novel treatment options for disease prevention and treatment. Synthetic messenger RNAs (mRNAs) are promising nucleic acid-based drugs to transiently express desired proteins that are missing or defective. Recently, synthetic mRNA-based vaccines encoding viral proteins have been approved for emergency use against COVID-19. Various types of vehicles, such as lipid nanoparticles (LNPs) and liposomes, are being investigated to enable the efficient uptake of mRNA molecules into desired cells. In addition, the introduction of novel chemical modifications into mRNAs increased the stability, enabled the modulation of nucleic acid-based drugs, and increased the efficiency of mRNA-based therapeutic approaches. In this review, novel and innovative strategies for the delivery of synthetic mRNA-based therapeutics for tissue regeneration are discussed. Moreover, with this review, we aim to highlight the versatility of synthetic mRNA molecules for various applications in the field of regenerative medicine and also discuss translational challenges and required improvements for mRNA-based drugs.

Nanoformulations of α-Mangostin for Cancer Drug Delivery System.

Natural compounds are emerging as effective agents for the treatment of malignant diseases. The active constituent of α-mangostin from the pericarp of Garcinia mangostana L. has earned significant interest as a plant base compound with anticancer properties. Despite α-mangostin’s superior properties as an anticancer agent, its applications are limited due to its poor solubility and physicochemical stability, rapid systemic clearance, and low cellular uptake. Our review aimed to summarize and discuss the nanoparticle formulations of α-mangostin for cancer drug delivery systems from published papers recorded in Scopus, PubMed, and Google Scholar. We investigated various types of α-mangostin nanoformulations to improve its anticancer efficacy by improving bioavailability, cellular uptake, and localization to specific areas These nanoformulations include nanofibers, lipid carrier nanostructures, solid lipid nanoparticles, polymeric nanoparticles, nanomicelles, liposomes, and gold nanoparticles. Notably, polymeric nanoparticles and nanomicelles can increase the accumulation of α-mangostin into tumors and inhibit tumor growth in vivo. In addition, polymeric nanoparticles with the addition of target ligands can increase the cellular uptake of α-mangostin. In conclusion, nanoformulations of α-mangostin are a promising tool to enhance the cellular uptake, accumulation in cancer cells, and the efficacy of α-mangostin as a candidate for anticancer drugs.

Efficient Treatment of Fish Intestinal Parasites Applying a Membrane-Penetrating Oral Drug Delivery Nanoparticle.

Nanodelivery of drugs aims to ensure drug stability in the face of adverse biochemical conditions in the course of administration, concomitant with appropriate pharmacological action provided by delivery at the targeted site. In this study, the application potential of a nanoparticle produced with biopolymers chitosan-N-arginine and alginate as an oral drug delivery material is evaluated. Both macromolecules being weak polyelectrolytes, the nanoparticle presents strong thermodynamic interactions with a biological model membrane consisting of a charged lipid liposome bilayer, leading to membrane disruption and membrane penetration of the nanoparticles in ideal conditions of pH corresponding to the oral route. The powder form of the nanoparticle was obtained by lyophilization and with a high percentage of entrapment of the anthelmintic drug praziquantel. In vivo studies were conducted with oral administration to Corydoras schwartzi fish with high intensity of intestinal parasites infection. The in vivo experiments confirmed the mucoadhesive and revealed membrane-penetrating properties of the nanoparticle by translocating the parasite cyst, which provided target drug release and reduction of over 97% of the fish intestinal parasites. Thus, it was evidenced that the nanoparticle was effective in transporting and releasing the drug to the target, providing an efficient treatment.

Lipid Nanocarriers for Hyperproliferative Skin Diseases.

Simple SummaryDifferent drugs, including antiproliferative and corticosteroids in general, are recommended for the treatment of hyperproliferative skin diseases (HSD). The effectiveness of many of these drugs is limited due to their low solubility in water and low penetration in the skin. The loading of these drugs in lipid nanocarriers, such as lipid nanoparticles and liposomes, has been considered as a successful solution to improve the drug bioavailability through the skin, to control their release kinetics and thus reduce the risk of potential side effects. In this work, we discuss the use of lipid nanocarriers loading drugs against HSD.Hyperproliferative skin diseases (HSD) are a group of diseases that include cancers, pre-cancerous lesions and diseases of unknown etiology that present different skin manifestations in terms of the degree and distribution of the injuries. Anti-proliferative agents used to treat these diseases are so diverse, including 5-aminolevulinic acid, 5-fluorouracil, imiquimod, methotrexate, paclitaxel, podophyllotoxin, realgar, and corticosteroids in general. These drugs usually have low aqueous solubility, which consequently decreases skin permeation. Thus, their incorporation in lipid nanocarriers has been proposed with the main objective to increase the effectiveness of topical treatment and reduce side effects. This manuscript aims to describe the advantages of using lipid nanoparticles and liposomes that can be used to load diversity of chemically different drugs for the treatment of HSD.

The Two Sweet Sides of Janus Lectin Drive Crosslinking of Liposomes to Cancer Cells and Material Uptake.

A chimeric, bispecific Janus lectin has recently been engineered with different, rationally oriented recognition sites. It can bind simultaneously to sialylated and fucosylated glycoconjugates. Because of its multivalent architecture, this lectin reaches nanomolar avidities for sialic acid and fucose. The lectin was designed to detect hypersialylation—a dysregulation in physiological glycosylation patterns, which promotes the tumor growth and progression of several cancer types. In this study, the characteristic properties of this bispecific Janus lectin were investigated on human cells by flow cytometry and confocal microscopy in order to understand the fundamentals of its interactions. We evaluated its potential in targeted drug delivery, precisely leading to the cellular uptake of liposomal content in human epithelial cancer cells. We successfully demonstrated that Janus lectin mediates crosslinking of glyco-decorated giant unilamellar vesicles (GUVs) and H1299 lung epithelial cells. Strikingly, the Janus lectin induced the internalization of liposomal lipids and also of complete GUVs. Our findings serve as a solid proof of concept for lectin-mediated targeted drug delivery using glyco-decorated liposomes as possible drug carriers to cells of interest. The use of Janus lectin for tumor recognition certainly broadens the possibilities for engineering diverse tailor-made lectin constructs, specifically targeting extracellular structures of high significance in pathological conditions.

Impact of formulation on the quality and stability of freeze-dried nanoparticles

Freeze-drying is an effective approach to improve the long-term stability of nanomedicines. Lyoprotectants are generally considered as requisite excipients to ensure that the quality of nanoparticles is maintained throughout the freeze-drying process. However, depending on the type of nanoparticles, the needs for lyoprotectants or the challenges they face during freeze-drying may be different. In this study, we compared and identified the impact of freeze-drying on key characteristics of three types of nanoparticles: solid lipid nanoparticles (SLNs), polymeric nanoparticles (PNs), and liposomes. Sucrose, trehalose, and mannitol were added to nanoparticle suspensions before freeze-drying. The same conservative freeze-drying conditions with controlled ice nucleation at −8 °C were employed for all formulations. The collapse temperatures of nanoparticle formulations were found to be the same as those of the lyoprotectant added, except PN formulation. Likely the poly(vinyl alcohol) (PVA) in the formulation induced a higher collapse temperature and retardation of drying of PNs. Freeze-drying of both SLNs and liposomes without lyoprotectants increased particle size and polydispersity, which was resolved by adding amorphous disaccharides. Regardless of the addition of lyoprotectants, freeze-drying did not alter the size of PNs possibly due to the protection from PVA. However, lyoprotectants were still necessary to shorten the reconstitution time and reduce the residual moisture. In conclusion, different types of nanoparticles face distinct challenges for freeze-drying, and lyoprotectants differentially affect various stability and quality attributes of freeze-dried nanoparticles.

Deciphering the role of nanoparticles for management of bacterial meningitis: an update on recent studies.

Meningitis is an inflammation of the protective membranes called meninges and fluid adjacent the brain and spinal cord. The inflammatory progression expands all through subarachnoid space of the brain and spinal cord and occupies the ventricles. The pathogens like bacteria, fungi, viruses, or parasites are main sources of infection causing meningitis. Bacterial meningitis is a life-threatening health problem that which needs instantaneous apprehension and treatment. Nesseria meningitidis, Streptococcus pneumoniae, and Haemophilus flu are major widespread factors causing bacterial meningitis. The conventional drug delivery approaches encounter difficulty in crossing this blood-brain barrier (BBB) and therefore are insufficient to elicit the desired pharmacological effect as required for treatment of meningitis. Therefore, application of nanoparticle-based drug delivery systems has become imperative for successful dealing with this deadly disease. The nanoparticles have ability to across BBB via four important transport mechanisms, i.e., paracellular transport, transcellular (transcytosis), endocytosis (adsorptive transcytosis), and receptor-mediated transcytosis. In this review, we reminisce distinctive symptoms of meningitis, and provide an overview of various types of bacterial meningitis, with a focus on its epidemiology, pathogenesis, and pathophysiology. This review describes conventional therapeutic approaches for treatment of meningitis and the problems encountered by them while transmitting across tight junctions of BBB. The nanotechnology approaches like functionalized polymeric nanoparticles, solid lipid nanoparticles, nanostructured lipid carrier, nanoemulsion, liposomes, transferosomes, and carbon nanotubes which have been recently evaluated for treatment or detection of bacterial meningitis have been focused. This review has also briefly summarized the recent patents and clinical status of therapeutic modalities for meningitis.

Non-invasive gene delivery across the blood-brain barrier: present and future perspectives.

Non-invasive gene delivery across the blood-brain barrier: present and future perspectives.

Dopamine-loaded lipid based nanocarriers for intranasal administration of the neurotransmitter: A comparative study

Both dopamine (DA) loaded Solid Lipid Nanoparticles (SLN) and liposomes (Lip), designed for intranasal administration of the neurotransmitter as an innovative Parkinson disease treatment, were already characterized in vitro in some extent by us (Trapani et al., 2018a and Cometa et al., 2020, respectively). Herein, to gain insight into the structure of SLN, X-ray Photoelectron Spectroscopy Analysis was carried out and DA-SLN (SLN 1) were found to exhibit high amounts of the neurotransmitter on the surface, whereas the external side of Glycol Chitosan (GCS) containing SLN (SLN 2) possessed only few amounts. However, SLN 2 were characterized by the highest encapsulation DA efficiency (i.e., 81%). Furthermore, in view of intranasal administration, mucoadhesion tests in vitro were also conducted for SLN and Lip formulations, evidencing high muchoadesive effect exerted by SLN 2. Concerning ex-vivo studies, SLN and Lip were found to be safe for Olfactory Ensheathing Cells and fluorescent SLN 2 were taken up in a dose-dependent manner reaching the 100% of positive cells, while Lip 2 (chitosan-glutathione-coated) were internalised by 70% OECs with six-times more lipid concentration. Hence, SLN 2 formulation containing DA and GCS may constitute interesting formulations for further studies and promising dosage form for non-invasive nose-to-brain neurotransmitter delivery.

Inhalable Spray Dried Pro-Liposome Powder Containing Budesonide for Pulmonary Delivery

Budesonide is an anti-asthmatic agent which is used to control the symptoms of asthma like bronchospasm, oedema. Drug delivered to lung through inhalation will provide systemic and local drug delivery at lower dose in chronic and acute diseases. Dry powder inhalers are the best choice for targeting the anti-asthmatic drugs through pulmonary route. The objective of the present study is to prepare inhalable lipid coated budesonide microparticles by spray drying method so effective delivery of budesonide to the lungs can be achieved. The microparticles in the form of dry powder were obtained by either spray drying liposomal drug suspension or lipid drug suspension. The liposomes were initially prepared by solvent evaporation method using Hydrogenated Soyabean Phosphatidylcholine and Cholesterol (1:1, 1:2, 2:1) as lipid carrier and then spray dried later with mannitol as bulking agent at different lipid to diluent ratio (1:1.25, 1:2.5 &amp; 1:5). The liposomes and liposomal dry powder were evaluated for vesicle size, % entrapment efficiency, in vitro drug release studies, powder characteristics, aerosol performance and stability studies. The liposomes prepared showed vesicle size (2-8 µm), Entrapment efficiency (92.22%) at lipid: drug ratio of (2.5:1) and observed 80.41 % drug release in 24 hrs. Pro-liposomes prepared by spray drying of liposomal drug suspension (LSD1) showed emitted dose, mean mass aerodynamic diameter, geometric standard deviation and fine particle fraction of 99.01%, 3.12 µm, 1.78 and 43.5% along with good powder properties. The spray dried powder was found to be stable at 4 ± 2 °C &amp; 65% ± 5 % RH. The inhalable microparticles containing Budesonide containing lipid dry powder was successfully prepared by spray drying method that showed good aerodynamic properties and stability with mannitol as diluent. The microparticles produced with this novel approach could deliver drug on target via inhalation route and also ease manufacture process at large scale in fewer production steps.

Optimization of Encapsulation Using Milk Polar Lipid Liposomes with S-Layer Protein and Transport Study of the ACE-Inhibitory Peptide RLSFNP.

The purpose of this study is to develop a new type of nanodrug delivery material by modifying milk polar lipid (MPL) liposomes with the S-layer protein. LIP-RLSFNP (MPL liposomes encapsulating RLSFNP (Arg-Leu-Ser-Phe-Asn-Pro)) and SLP-LIP-RLSFNP (S-layer protein-modified LIP-RLSFNP) were prepared and characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, confocal laser scanning microscopy, surface plasmon resonance, and mastersizer dynamic light scattering measurements. The results showed that the S-layer protein could modify the surface of MPL liposomes, stabilize the shape of the vesicles, and improve the resistance to external interference. Furthermore, SLP-LIP-RLSFNP showed better performance in in vitro and in vivo experiments compared with LIP-RLSFNP in terms of promoting absorption and delayed release. The findings suggested that MPL liposomes modified with the S-layer protein have potential for use as an effective delivery system for therapeutic proteins and peptides.

Action Mechanisms of Curcumin in Alzheimer's Disease and Its Brain Targeted Delivery.

AD is a chronic neurodegenerative disease. Many different signaling pathways, such as Wnt/β-catenin, Notch, ROS/JNK, and PI3K/Akt/mTOR are involved in Alzheimer’s disease and crosstalk between themselves. A promising treatment involves the uses of flavonoids, and one of the most promising is curcumin; however, because it has difficulty permeating the blood–brain barrier (BBB), it must be encapsulated by a drug carrier. Some of the most frequently studied are lipid nanocarriers, liposomes, micelles and PLGA. These carriers are further conjugated with brain-targeting agents such as lactoferrin and transferrin. In this review paper, curcumin and its therapeutic effects, which have been examined in vivo, are analyzed and then the delivery systems to the brain are addressed. Overall, the analysis of the literature revealed great potential for curcumin in treating AD and indicated the challenges that require further research.

Preparation of Artificial Red Blood Cells (Hemoglobin Vesicles) Using the Rotation-Revolution Mixer for High Encapsulation Efficiency.

Hemoglobin vesicles (Hb-V) are artificial red blood cells encapsulating highly concentrated hemoglobin (Hb) in liposomes comprising phospholipids, cholesterol, negatively charged lipids, and polyethylene glycol (PEG)-conjugated phospholipids. Safety and efficacy of Hb-V as a transfusion alternative have been extensively studied. For this study, we prepared Hb-V using the kneading method with a rotation-revolution mixer as an alternative to the conventional extrusion method. We optimized the kneading operation parameters to obtain Hb-V with a high yield. Results show that the Hb encapsulation efficiency was increased dramatically up to 74.2%, which is higher than that of the extrusion method (20%) because the kneading method enabled mixing of a highly concentrated carbonylhemoglobin (HbCO) solution (40 g/dL) and a considerably large amount of powdered lipids in only 10 min. The high viscosity of the Hb-lipid mixture paste (ca. 103-105 cP) favorably induces frictional heat by kneading and increases the paste temperature (ca. 60 °C), which facilitates lipid dispersion and liposome formation. During the kneading operation using a thermostable HbCO solution, Hb denaturation was prevented. Hb-V prepared using this method showed no marked changes in particle sizes, Hb denaturation, or Hb leakage from liposomes during two years of long-term storage-stability tests. Collectively, these results demonstrate that the kneading method using a rotation-revolution mixer shows good potential as a new method to produce Hb-V.

Singlet Oxygen Generation in Dark‐Hypoxia by Catalytic Microenvironment‐Tailored Nanoreactors for NIR‐II Fluorescence‐Monitored Chemodynamic Therapy

AbstractSinglet oxygen (1O2) has a potent anticancer effect, but photosensitized generation of1O2is inhibited by tumor hypoxia and limited light penetration depth. Despite the potential of chemodynamic therapy (CDT) to circumvent these issues by exploration of1O2‐producing catalysts, engineering efficient CDT agents is still a formidable challenge since most catalysts require specific pH to function and become inactivated upon chelation by glutathione (GSH). Herein, we present a catalytic microenvironment‐tailored nanoreactor (CMTN), constructed by encapsulating MoO42−catalyst and alkaline sodium carbonate within liposomes, which offers a favorable pH condition for MoO42−‐catalyzed generation of1O2from H2O2and protects MoO42−from GSH chelation owing to the impermeability of liposomal lipid membrane to ions and GSH. H2O2and1O2can freely cross the liposomal membrane, allowing CMTN with a built‐in NIR‐II ratiometric fluorescent1O2sensor to achieve monitored tumor CDT.

Singlet Oxygen Generation in Dark-Hypoxia by Catalytic Microenvironment-Tailored Nanoreactors for NIR-II Fluorescence-Monitored Chemodynamic Therapy.

Singlet oxygen (1 O2 ) has a potent anticancer effect, but photosensitized generation of 1 O2 is inhibited by tumor hypoxia and limited light penetration depth. Despite the potential of chemodynamic therapy (CDT) to circumvent these issues by exploration of 1 O2 -producing catalysts, engineering efficient CDT agents is still a formidable challenge since most catalysts require specific pH to function and become inactivated upon chelation by glutathione (GSH). Herein, we present a catalytic microenvironment-tailored nanoreactor (CMTN), constructed by encapsulating MoO42- catalyst and alkaline sodium carbonate within liposomes, which offers a favorable pH condition for MoO42- -catalyzed generation of 1 O2 from H2 O2 and protects MoO42- from GSH chelation owing to the impermeability of liposomal lipid membrane to ions and GSH. H2 O2 and 1 O2 can freely cross the liposomal membrane, allowing CMTN with a built-in NIR-II ratiometric fluorescent 1 O2 sensor to achieve monitored tumor CDT.

HPLC-DAD-CAD-based approach for the simultaneous analysis of hydrophobic drugs and lipid compounds in liposomes and for cyclodextrin/drug inclusion complexes

In recent decades liposomes have become attractive carriers for hydrophobic drugs to enhance their solubility and improve their therapeutic application. For liposomal drug products, both drug and lipid quantification are required by regulatory authorities, making the implementation of precise quantification methods a step of crucial importance in formulation development and quality control. Therefore, the present study is focused on the development and validation of a simple and time-saving method for the simultaneous analysis of hydrophobic drugs and conventional liposomal components. The new HPLC method was established with a combined detection by a diode array detector (DAD) and a corona charged aerosol detector (CAD). As a wide calibration range of the liposomal components can be achieved (10−1000 μg/mL), the analysis of samples with different drug to lipid ratios is enabled. Moreover, an excellent precision including repeatability and low limits of detection (≤ 1.8 μg/mL) and limits of quantification (≤ 5.9 μg/mL) were accomplished for all analytes. The method was successfully applied to liposomes incorporating mitotane. Everolimus was additionally analyzed as hydrophobic model drug. Furthermore, cyclodextrin/mitotane inclusion complexes were investigated to proof a broad range of applications for the developed method.

Spectroscopy of model-membrane liposome-protein systems: complementarity of linear dichroism, circular dichroism, fluorescence and SERS.

A range of membrane models have been developed to study components of cellular systems. Lipid vesicles or liposomes are one such artificial membrane model which mimics many properties of the biological system: they are lipid bilayers composed of one or more lipids to which other molecules can associate. Liposomes are thus ideal to study the roles of cellular lipids and their interactions with other membrane components to understand a wide range of cellular processes including membrane disruption, membrane transport and catalytic activity. Although liposomes are much simpler than cellular membranes, they are still challenging to study and a variety of complementary techniques are needed. In this review article, we consider several currently used analytical methods for spectroscopic measurements of unilamellar liposomes and their interaction with proteins and peptides. Among the variety of spectroscopic techniques seeing increasing application, we have chosen to discuss: fluorescence based techniques such as FRET (fluorescence resonance energy transfer) and FRAP (fluorescence recovery after photobleaching), that are used to identify localisation and dynamics of molecules in the membrane; circular dichroism (CD) and linear dichroism (LD) for conformational and orientation changes of proteins on membrane binding; and SERS (Surface Enhanced Raman Spectroscopy) as a rapidly developing ultrasensitive technique for site-selective molecular characterisation. The review contains brief theoretical basics of the listed techniques and recent examples of their successful applications for membrane studies.