Lipidic Nanoparticles, Extracellular Vesicles and Hybrid Platforms as Advanced Medicinal Products: Future Therapeutic Prospects for Neurodegenerative Diseases.

Neurodegenerative diseases, such as Alzheimer's and Parkinson's, affect a wide variety of the population and pose significant challenges with progressive and irreversible neural cell loss. The limitations of brain-targeting therapies and the unclear molecular mechanisms driving neurodegeneration hamper the possibility of developing successful treatment options. Thus, nanoscale drug delivery platforms offer a promising solution. This paper explores and compares lipidic nanoparticles, extracellular vesicles (EVs), and hybrid liposomal-EV nanoplatforms as advanced approaches for targeted delivery to combat neurodegeneration. Lipidic nanoparticles are well-characterized platforms that allow multi-drug loading and scalable production. Conversely, EVs offer the ability of selectively targeting specific tissues and high biocompatibility. The combination of these two platforms in one could lead to promising results in the treatment of neurodegeneration. However, many issues, such as the regulatory framework, remain to be solved before these novel products are translated into clinical practice.

Exosome-like genistein-loaded nanoparticles developed by thin-film hydration and 3D-printed Tesla microfluidic chip: A comparative study.

Exosomes are naturally derived information carriers that present interest as drug delivery systems. However, their vague cargo and isolation difficulties hinder their use in clinical practice. To overcome these limitations, we developed exosome-like nanoparticles, consisted of the main lipids of exosomes, using two distinct methods: thin-film hydration and 3D-printed microfluidics. Our novel microfluidic device, fabricated through digital light processing printing, demonstrated a favorable architecture to produce exosome-like nanoparticles. We compared these two techniques by analyzing the physicochemical characteristics (size, size distribution, and ζ-potential) of both unloaded and genistein-loaded exosome-like nanoparticles, using dynamic and electrophoretic light scattering. Our findings revealed that the presence of small lipophilic molecules, cholesterol and/or genistein, influenced the characteristics of the final formulations differently based on the development approach. Regardless of the initial differences of the formulations, all exosome-like nanoparticles, whether loaded with genistein or not, exhibited remarkable colloidal stability over time. Furthermore, an encapsulation efficiency of over 87% for genistein was achieved in all cases. Additionally, thermal analysis uncovered the presence of metastable phases within the membranes, which could impact the drug delivery efficiency. In summary, this study provides a comprehensive comparison between conventional and innovative methods for producing complex liposomal nanosystems, exemplified by exosome-like nanoparticles.

Preclinical evaluation of modified carbon nanohorns and their complexation with insulin.

The current study emphasizes the minimal toxicity observed in vitro and in vivo for carbon nanohorns (CNHs) modified with third generation polyamidoamine (PAMAM) dendrimers. Initially, we investigated the interactions between CNH-PAMAM and lipid bilayers, which were utilized as representative models of cellular membranes for the evaluation of their toxicity in vitro. We found that the majority of those interactions occur between the modified CNHs and the polar groups of phospholipids, meaning that CNH-PAMAM does not incorporate into the lipid chains, and thus, disruption of the lipid bilayer structure is avoided. This outcome is a very important observation for further evaluation of CNH-PAPAM in cell lines and in animal models. Next, we demonstrated the potential of CNH-PAMAM for complexation with insulin, as a proof of concept for its employment as a delivery platform. Importantly, our study provides comprehensive evidence of low toxicity for CNH-PAMAM both in vitro and in vivo. The assessment of cellular toxicity revealed that the modified CNHs exhibited minimal toxicity, with concentrations of 151 µg mL-1 and 349 µg mL-1, showing negligible harm to EO771 cells and mouse embryonic fibroblasts (MEFs), respectively. Moreover, the histological analysis of the mouse livers demonstrated no evidence of tissue necrosis and inflammation, or any visible signs of severe toxicity. These findings collectively indicate the safe profile of CNH-PAMAM and further contribute to the growing body of knowledge on the safe and efficient utilization of CNH-based nanomaterials in drug and protein delivery applications.

The Regulatory Landscape of New Health Technologies and Nanotechnologies: The Role of Complexity of Nanosystems.

Herein we present the modern issue of new health technologies that emerge in Medicine and Therapeutics, with regard to their development, regulatory framework, approval, and post-approval monitoring. The European law and legislation distinguish the various subcategories of health technologies in medicinal products, medical devices, biotechnological products, advanced therapy medicinal products, and nanomedicinal products. Each of these categories presents its own distinctive characteristics, based on principles that regard the development technology and intended therapeutic use, and, as a result, is defined by a unique regulatory framework inside the European legislation environment. New health technologies are a key of twenty-first-century knowledge, science, and economy and a part of society growth and economic development, while at the same time they present significant challenges, mainly through matters that regard their safety, efficacy, and value for the public. In this environment, the concept of complexity of living and artificial systems arises, as part of their nature, but also as a perspective that will give answers regarding their dynamic behavior, evolution, and overall quality.

Development of Liposomal and Liquid Crystalline Lipidic Nanoparticles with Non-Ionic Surfactants for Quercetin Incorporation.

The aim of the present study is the development, physicochemical characterization, and in vitro cytotoxicity evaluation of both empty and quercetin-loaded HSPC (hydrogenated soy phosphatidylcholine) liposomes, GMO (glyceryl monooleate) liquid crystalline nanoparticles, and PHYT (phytantriol) liquid crystalline nanoparticles. Specifically, HSPC phospholipids were mixed with different non-ionic surfactant molecules (Tween 80 and/or Span 80) for liposomal formulations, whereas both GMO and PHYT lipids were mixed with Span 80 and Tween 80 as alternative stabilizers, as well as with Poloxamer P407 in different ratios for liquid crystalline formulations. Subsequently, their physicochemical properties, such as size, size distribution, and ζ-potential were assessed by the dynamic and electrophoretic light scattering (DLS/ELS) techniques in both aqueous and biological medium with serum proteins. The in vitro biological evaluation of the empty nanosystems was performed by using the MTT cell viability and proliferation assay. Finally, the entrapment efficiency of quercetin was calculated and the differences between the two different categories of lipidic nanoparticles were highlighted. According to the results, the incorporation of the non-ionic surfactants yields a successful stabilization and physicochemical stability of both liposomal and liquid crystalline nanoparticles. Moreover, in combination with an appropriate biosafety in vitro profile, increased encapsulation efficiency of quercetin was achieved. Overall, the addition of surfactants improved the nanosystem's stealth properties. In conclusion, the results indicate that the physicochemical properties were strictly affected by the formulation parameters, such as the type of surfactant.

Interaction of Rhus typhina Tannin with Lipid Nanoparticles: Implication for the Formulation of a Tannin-Liposome Hybrid Biomaterial with Antibacterial Activity.

Tannins are natural plant origin polyphenols that are promising compounds for pharmacological applications due to their strong and different biological activities, including antibacterial activity. Our previous studies demonstrated that sumac tannin, i.e., 3,6-bis-O-di-O-galloyl-1,2,4-tri-O-galloyl-ß-D-glucose (isolated from Rhus typhina L.), possesses strong antibacterial activity against different bacterial strains. One of the crucial factors of the pharmacological activity of tannins is their ability to interact with biomembranes, which may result in the penetration of these compounds into cells or the realization of their activity on the surface. The aim of the current work was to study the interactions of sumac tannin with liposomes as a simple model of the cellular membrane, which is widely used in studies focused on the explanation of the physicochemical nature of molecule-membrane interactions. Additionally, these lipid nanovesicles are very often investigated as nanocarriers for different types of biologically active molecules, such as antibiotics. In the frame of our study, using differential scanning calorimetry, zeta-potential, and fluorescence analysis, we have shown that 3,6-bis-O-di-O-galloyl-1,2,4-tri-O-galloyl-ß-D-glucose interacts strongly with liposomes and can be encapsulated inside them. A formulated sumac-liposome hybrid nanocomplex demonstrated much stronger antibacterial activity in comparison with pure tannin. Overall, by using the high affinity of sumac tannin to liposomes, new, functional nanobiomaterials with strong antibacterial activity against Gram-positive strains, such as S. aureus, S. epidermitis, and B. cereus, can be formulated.

Concomitant delivery of doxorubicin and cisplatin through liposome-based thermosensitive nanoparticles: perspective in the treatment of cancer in animal models.

The temperature sensitive liposomal formulations are a promising tool to improve the therapeutic index of the drugs with minimal toxicity. The aim of this study was to investigate the potential of concomitant delivery of cisplatin (Cis) and doxorubicin (Dox) containing thermosensitive liposomes (TSLs) with mild hyperthermia against cancer in vitro and in vivo. The polyethylene glycol coated DPPC/DSPC, thermosensitive and DSPC, non-thermosensitive liposomes incorporating Cis and Dox were prepared and characterized. A conventional Differential Scanning Calorimetry (DSC) technique and Fourier Transform Infrared Spectroscopy (FT-IR) were applied to study drug-phospholipid interaction and compatibility. The chemotherapeutic efficacy of these formulations was evaluated in benzo[a]pyrene (BaP) induced fibrosarcoma under hyperthermic condition. The size diameter of prepared thermosensitive liposomes was measured to be 120 ± 10 nm. The DSC data exhibited the changes in the curves of DSPC + Dox and DSPC + Cis while comparing the pure DSPC and drugs. However, the FITR showed same spectrum of phospholipids and drugs individually and in the mixture as well. The data showed higher efficacy of Cis-Dox-TSL as 84% inhibition in tumor growth was recorded in this group of animals in hyperthermic condition. The Kaplan-Meir curve revealed, 100% and 80% survival of the animals in the groups treated with Cis-Dox-TSL under hyperthermia and Cis-Dox-NTSL without hyperthermia, respectively. However, Cis-TSL as well as Dox-TSL exhibited 50% survival, while only 20% survival was recorded in the groups of animals treated with Dox-NTSL and Cis-NTSL. The flow cytometry analysis revealed that Cis-Dox-NTSL augments the induction of apoptosis in the tumor cells which was recorded as 18%. As expected, Cis-Dox-TSL showed great potential as 39% of cells were measured as apoptotic cells, significantly very high in comparison to Cis-Dox-NTSL, Dox-TSL and Cis-TSL as well. The apoptotic analysis of the cells by flow cytometry clearly indicated the effect of hyperthermia during the treatment while Cis-Dox-TSL formulation was administered. Finally, the immunohistochemical analysis of the tumor tissues by confocal microscopy exhibited several fold increases in the expression of pAkt in the animals treated with vehicles in Sham-NTSL as well as Sham-TSL. However, Cis-Dox-TSL showed great reduction in the expression of Akt, as it declined by 11-fold. The results of the present study directed the role of concomitant delivery doxorubicin and cisplatin containing thermosensitive liposomes under hyperthermic conditions for the development of a novel therapeutic strategy for the treatment of cancer.

A mini review for lipid-based nanovaccines: from their design to their applications.

Nanovaccines have shown to be effective, and this is the reason they are preferred than conventional vaccines. The scope of this review is to describe the role, mechanisms, and advantages of nano vaccines based on lipids, and present the most important types, their physicochemical characteristics, as well as their challenges. The most important categories of lipid nano-vaccines are liposomal nano vaccines and (virus-lipid nanoparticles (NPs)/virosomes. Examples of vaccine formulations from each category are presented and analyzed below, focusing on their structure and physicochemical characteristics. In all cases, a nanoscale platform is used, enriched with adjuvants, antigens, and other helping agents to trigger immune response process and achieve cell targeting, and eventually immunity against the desired disease. The exact mechanism of action of each vaccine is not always completely known or understood. Physicochemical characteristics, such as particle size, morphology/shape, and zeta potential are also mentioned as they seem to affect the properties and mechanism of action of the vaccine formulation.

Method of Simultaneous Analysis of Liposome Components Using HPTLC/FID.

Liposomes are composed of different kinds of lipids or lipophilic substances and are used as carriers of bioactive molecules. The characterization of the prepared liposomes consists of the calculation of the drug-to-lipid-molar ratio by measuring the lipids and the encapsulated molecule.The present work describes an analytical methodology for the simultaneous determination of all the lipid ingredients of liposome formulation using thin-layer chromatography coupled with a flame ionization detector (TLC/FID), employing the least possible sample quantity. The method consists of the chromatographic separation of the liposomal ingredients on silica gel scintillated on quartz rods and the subsequent detection of the ingredients by scanning the rods through hydrogen flame. The produced ions are detected by a flame ionization detector, and the signal is converted to a chromatogram.This method may be applied at every step of the liposome preparation for examining the quality of the raw materials, tracking possible errors in the preparation procedure, and finally analyzing the content of the final liposomal composition.

Synthesis and Testing of Analogs of the Tuberculosis Drug Candidate SQ109 against Bacteria and Protozoa: Identification of Lead Compounds against Mycobacterium abscessus and Malaria Parasites.

SQ109 is a tuberculosis drug candidate that has high potency against Mycobacterium tuberculosis and is thought to function at least in part by blocking cell wall biosynthesis by inhibiting the MmpL3 transporter. It also has activity against bacteria and protozoan parasites that lack MmpL3, where it can act as an uncoupler, targeting lipid membranes and Ca2+ homeostasis. Here, we synthesized 18 analogs of SQ109 and tested them against M. smegmatis, M. tuberculosis, M. abscessus, Bacillus subtilis, and Escherichia coli, as well as against the protozoan parasites Trypanosoma brucei, T. cruzi, Leishmania donovani, L. mexicana, and Plasmodium falciparum. Activity against the mycobacteria was generally less than with SQ109 and was reduced by increasing the size of the alkyl adduct, but two analogs were ∼4-8-fold more active than SQ109 against M. abscessus, including a highly drug-resistant strain harboring an A309P mutation in MmpL3. There was also better activity than found with SQ109 with other bacteria and protozoa. Of particular interest, we found that the adamantyl C-2 ethyl, butyl, phenyl, and benzyl analogs had 4-10× increased activity against P. falciparum asexual blood stages, together with low toxicity to a human HepG2 cell line, making them of interest as new antimalarial drug leads. We also used surface plasmon resonance to investigate the binding of inhibitors to MmpL3 and differential scanning calorimetry to investigate binding to lipid membranes. There was no correlation between MmpL3 binding and M. tuberculosis or M. smegmatis cell activity, suggesting that MmpL3 is not a major target in mycobacteria. However, some of the more active species decreased lipid phase transition temperatures, indicating increased accumulation in membranes, which is expected to lead to enhanced uncoupler activity.

Development of stimuli-responsive lyotropic liquid crystalline nanoparticles targeting lysosomes: Physicochemical, morphological and drug release studies.

The abilities of sub-cellular targeting and stimuli-responsiveness are critical challenges in pharmaceutical nanotechnology. In the present study, glyceryl monooleate (GMO)-based non-lamellar lyotropic liquid crystalline nanoparticles were stabilized by the poly(2-(dimethylamino)ethyl methacrylate)-b-poly(lauryl methacrylate) block copolymer carrying tri-phenyl-phosphine cations (TPP-QPDMAEMA-b-PLMA), either used alone or in combination with other polymers as co-stabilizers. The systems were designed to perform simultaneously sub-cellular targeting, stimuli-responsiveness and to exhibit stealthiness. The physicochemical characteristics and fractal dimensions of the resultant nanosystems were obtained from light scattering techniques, while their micropolarity and microfluidity from fluorescence spectroscopy. Their morphology was assessed by cryo-TEM, while their thermal behavior by microcalorimetry and high-resolution ultrasound spectroscopy. The analyzed properties, including the responsiveness to pH and temperature, were found to be dependent on the combination of the polymeric stabilizers. The subcellular localization was monitored by confocal microscopy, revealing targeting to lysosomes. Subsequently, resveratrol was loaded into the nanosystems, the entrapment efficiency was investigated and in vitro release studies were carried out at different conditions, in which a stimuli-triggered drug release profile was achieved. In conclusion, the proposed multi-functional nanosystems can be considered as potentially stealth, stimuli-responsive drug delivery nanocarriers, with targeting ability to lysosomes and presenting a stimuli-triggered drug release profile.

Protein-liposome interactions: the impact of surface charge and fluidisation effect on protein binding.

At the dawn of a new nanotechnological era in the pharmaceutical field, it is very important to examine and understand all the aspects that influence in vivo behaviour of nanoparticles. In this point of view, the interactions between serum proteins and liposomes with incorporated anionic, cationic, and/or PEGylated lipids were investigated to elucidate the role of surface charge and bilayer fluidity in protein corona's formation. 1,2-dipalmitoyl-sn-glycero-3- phosphocholine (DPPC), hydrogenated soybean phosphatidylcholine (HSPC), and 1,2-dioctadecanoyl-sn-glycero-3-phosphocholine (DSPC) liposomes with the presence or absence of 1,2-dipalmitoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (sodium salt) (DPPG), 1,2-di-(9Z-octadecenoyl)-3-trimethylammonium-propane (chloride salt) (DOTAP), and/or 1,2-dipalmitoylsn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-5000] (DPPE-PEG 5000) lipids were prepared by the thin-film hydration method. The evaluation of their biophysical characteristics was enabled by differential scanning calorimetry and dynamic and electrophoretic light scattering. The physicochemical characteristics of mixed liposomes were compared before and after exposure to foetal bovine serum (FBS) and were correlated to calorimetric data. Our results indicate protein binding to all liposomal formulations. However, it is highlighted the importance of surface charge and fluidisation effect to the extent of protein adsorption. Additionally, considering the extensive use of cationic lipids for innovative delivery platforms, we deem PEGylation a key parameter, because even in a small proportion can reduce protein binding, and thus fast clearance and extreme toxicity without affecting positive charge. This study is a continuation of our previous work about protein-liposome interactions and fraction of stealthiness (Fs) parameter, and hopefully a design road map for drug and gene delivery.

Amphiphilic Copolymer-Lipid Chimeric Nanosystems as DNA Vectors.

Lipid-polymer chimeric (hybrid) nanosystems are promising platforms for the design of effective gene delivery vectors. In this regard, we developed DNA nanocarriers comprised of a novel poly[(stearyl methacrylate-co-oligo(ethylene glycol) methyl ether methacrylate] [P(SMA-co-OEGMA)] amphiphilic random copolymer, the cationic 1,2-dioleoyl-3-(trimethylammonium) propane (DOTAP), and the zwitterionic L-α-phosphatidylcholine, hydrogenated soybean (soy) (HSPC) lipids. Chimeric HSPC:DOTAP:P[(SMA-co-OEGMA)] nanosystems, and pure lipid nanosystems as reference, were prepared in several molar ratios of the components. The colloidal dispersions obtained presented well-defined physicochemical characteristics and were further utilized for the formation of lipoplexes with a model DNA of linear topology containing 113 base pairs. Nanosized complexes were formed through the electrostatic interaction of the cationic lipid and phosphate groups of DNA, as observed by dynamic, static, and electrophoretic light scattering techniques. Ultraviolet-visible (UV-Vis) and fluorescence spectroscopy disclosed the strong binding affinity of the chimeric and also the pure lipid nanosystems to DNA. Colloidally stable chimeric/lipid complexes were formed, whose physicochemical characteristics depend on the N/P ratio and on the molar ratio of the building components. Cryogenic transmission electron microscopy (Cryo-TEM) revealed the formation of nanosystems with vesicular morphology. The results suggest the successful fabrication of these novel chimeric nanosystems with well-defined physicochemical characteristics, which can form stable lipoplexes.

Development of Ulvan-Containing Liposomes as Antibacterial Drug Delivery Platforms.

Liposomes, due to their safety profile and targeting ability, are among the most studied nanocarriers as antimicrobial delivery systems. However, due to lack of stability and the non-specific interaction of liposomes with cells and proteins, their use is relatively limited. Aiming to overcome these drawbacks, it was envisaged that incorporation of ulvan, a bioactive marine sulfated polysaccharide isolated from green algae, in liposomes could improve their physicochemical properties and overall stability. Thus, we initially studied the interactions of ulvan with neutral, negatively, and positively charged lipids using Differential Scanning Calorimetry and subsequently, based on the obtained results, we prepared the respective ulvan-containing neutral and charged liposomes, where ulvan interacts with both lipid chains and polar groups in the liposomal bilayer. In a further step, we entrapped in the liposomes fusidic acid, used as a model antibacterial drug, and proceeded with the evaluation of their antibacterial activity against Staphylococcus aureus. The physicochemical properties (size and ζ-potential), stability, morphology, and entrapment efficiency of the prepared liposomal formulations were determined.

Lipid-based nanoparticles and RNA as innovative neuro-therapeutics.

RNA-delivery is a promising tool to develop therapies for difficult to treat diseases such as neurological disorders, by silencing pathological genes or expressing therapeutic proteins. However, in many cases RNA delivery requires a vesicle that could effectively protect the molecule from bio-degradation, bypass barriers i.e., the blood brain barrier, transfer it to a targeted tissue and efficiently release the RNA inside the cells. Many vesicles such as viral vectors, and polymeric nanoparticles have been mentioned in literature. In this review, we focus in the discussion of lipid-based advanced RNA-delivery platforms. Liposomes and lipoplexes, solid lipid nanoparticles and lipid nanoparticles are the main categories of lipidic platforms for RNA-delivery to the central nervous systems (CNS). A variety of surface particles' modifications and routes of administration have been studied to target CNS providing encouraging results in vivo. It is concluded that lipid-based nanoplatforms will play a key role in the development of RNA neuro-therapies.

In vitro and in vivo activity of thermosensitive liposomes loaded with doxorubicin and cisplatin.

Thermosensitive liposomes loaded with cisplatin and doxorubicin composed of DPPC, DSPC, and DPPE-PEG5000 with different ratios were prepared by thin film hydration method. The Differential Scanning Calorimetry (DSC) curves showed that the liposomes composed of DPPC-DSPC-DPPE-PEG5000 with phospholipid ratio 95:5:0.05 w/w were a suitable formulation as thermosensitive liposomes with a DSC peak at 42.1 °C. The effect of doxorubicin and cisplatin encapsulated non-thermosensitive and thermosensitive liposomes on cellular proliferation and IC50 in SKBR3 & MDA-MB-231 breast cancer and PC-3 & LNcaP prostate cancer cell lines was investigated. The results showed that doxorubicin loaded into thermosensitive liposomes showed 20-fold decrease in the IC50 at 42 °C while comparing it with the same at 37 °C. Also, the results showed a more than 35-fold and 12-fold decrease in the IC50 of cisplatin thermosensitive liposomes at 42 °C, while compared with free cisplatin and cisplatin thermosensitive liposomes at any temperature. The in vivo results showed that the effect of doxorubicin encapsulated thermosensitive liposomes at hyperthermic conditions during the treatment as the tumor growth inhibition was measured 1.5-fold higher than any of the liposomal formulations of doxorubicin. It was also noticed that the tumor volume reduced to 150 mm3 in doxorubicin thermosensitive liposomes (G8) after 3 weeks during the treatment, but increased to 196 mm3 after 4 weeks. The Kaplan-Meir curve showed the 100% survival of the animals from G8 (thermosensitive liposomes containing doxorubicin plus hyperthermia) after 12 weeks. The flow cytometry data revealed more than 25% apoptotic cells and 6.25% necrotic cells in the tumor cells from the tissues of the G8 group of the animals. The results clearly indicate the superior efficacy of doxorubicin and cisplatin containing thermosensitive liposomes treatment during hyperthermia.

Aqueous Heat Method for the Preparation of Hybrid Lipid-Polymer Structures: From Preformulation Studies to Protein Delivery.

Liposomes with adjuvant properties are utilized to carry biomolecules, such as proteins, that are often sensitive to the stressful conditions of liposomal preparation processes. The aim of the present study is to use the aqueous heat method for the preparation of polymer-grafted hybrid liposomes without any additional technique for size reduction. Towards this scope, liposomes were prepared through the combination of two different lipids with adjuvant properties, namely dimethyldioctadecylammonium (DDA) and D-(+)-trehalose 6,6'-dibehenate (TDB) and the amphiphilic block copolymer poly(2-(dimethylamino)ethyl methacrylate)-b-poly(lauryl methacrylate) (PLMA-b-PDMAEMA). For comparison purposes, PAMAM dendrimer generation 4 (PAMAM G4) was also used. Preformulation studies were carried out by differential scanning calorimetry (DSC). The physicochemical characteristics of the prepared hybrid liposomes were evaluated by light scattering and their morphology was evaluated by cryo-TEM. Subsequently, in vitro nanotoxicity studies were performed. Protein-loading studies with bovine serum albumin were carried out to evaluate their encapsulation efficiency. According to the results, PDMAEMA-b-PLMA was successfully incorporated in the lipid bilayer, providing improved physicochemical and morphological characteristics and the ability to carry higher cargos of protein, compared to pure DDA:TDB liposomes, without affecting the biocompatibility profile. In conclusion, the aqueous heat method can be applied in polymer-grafted hybrid liposomes for protein delivery without further size-reduction processes.

Lyotropic Liquid Crystalline Nanostructures as Drug Delivery Systems and Vaccine Platforms.

Lyotropic liquid crystals result from the self-assembly process of amphiphilic molecules, such as lipids, into water, being organized in different mesophases. The non-lamellar formed mesophases, such as bicontinuous cubic (cubosomes) and inverse hexagonal (hexosomes), attract great scientific interest in the field of pharmaceutical nanotechnology. In the present review, an overview of the engineering and characterization of non-lamellar lyotropic liquid crystalline nanosystems (LLCN) is provided, focusing on their advantages as drug delivery nanocarriers and innovative vaccine platforms. It is described that non-lamellar LLCN can be utilized as drug delivery nanosystems, as well as for protein, peptide, and nucleic acid delivery. They exhibit major advantages, including stimuli-responsive properties for the "on demand" drug release delivery and the ability for controlled release by manipulating their internal conformation properties and their administration by different routes. Moreover, non-lamellar LLCN exhibit unique adjuvant properties to activate the immune system, being ideal for the development of novel vaccines. This review outlines the recent advances in lipid-based liquid crystalline technology and highlights the unique features of such systems, with a hopeful scope to contribute to the rational design of future nanosystems.

Losartan Interactions with 2-Hydroxypropyl-ß-CD.

Losartan potassium salt (LSR) is a well-known antihypertensive drug with proven beneficial effects on human health. Its formulation with the non-toxic 2-hydroxypropyl-ß-cyclodextrin (2-HP-ß-CD) could improve its pharmacological profile. Thus, its molecular interactions are studied using a combination of Differential Scanning Calorimetry (DSC), Nuclear Magnetic Resonance (NMR) and Molecular Dynamics (MD). First, its complexation is shown through Differential Scanning Calorimetry as lyophilization provided distinct thermal properties in comparison to the mixture. The complexation is further proved by utilizing the chemical shift changes in the complexation and T1 values. Furthermore, the reversible favorable complexation was shown by MD calculations. Such physical chemical properties provide evidence that this formulation must be further explored through biological experiments.

Hydrophilic Random Cationic Copolymers as Polyplex-Formation Vectors for DNA.

Research on the improvement and fabrication of polymeric systems as non-viral gene delivery carriers is required for their implementation in gene therapy. Random copolymers have not been extensively utilized for these purposes. In this regard, double hydrophilic poly[(2-(dimethylamino) ethyl methacrylate)-co-(oligo(ethylene glycol) methyl ether methacrylate] [P(DMAEMA-co-OEGMA)] random copolymers were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. The copolymers were further modified by quaternization of DMAEMA tertiary amine, producing the cationic P(QDMAEMA-co-OEGMA) derivatives. Fluorescence and ultraviolet-visible (UV-vis) spectroscopy revealed the efficient interaction of copolymers aggregates with linear DNAs of different lengths, forming polyplexes, with the quaternized copolymer aggregates exhibiting stronger binding affinity. Light scattering techniques evidenced the formation of polyplexes whose size, molar mass, and surface charge strongly depend on the N/P ratio (nitrogen (N) of the amine group of DMAEMA/QDMAEMA over phosphate (P) groups of DNA), DNA length, and length of the OEGMA chain. Polyplexes presented colloidal stability under physiological ionic strength as shown by dynamic light scattering. In vitro cytotoxicity of the empty nanocarriers was evaluated on HEK293 as a control cell line. P(DMAEMA-co-OEGMA) copolymer aggregates were further assessed for their biocompatibility on 4T1, MDA-MB-231, MCF-7, and T47D breast cancer cell lines presenting high cell viability rates.