One-step rapid tracking and isolation of senescent cells in cellular systems, tissues, or animal models via GLF16

Identification and isolation of senescent cells is challenging, rendering their detailed analysis an unmet need. We describe a precise one-step protocol to fluorescently label senescent cells, for flow cytometry and fluorescence microscopy, implementing a fluorophore-conjugated Sudan Black-B analog, GLF16. Also, a micelle-based approach allows identification of senescent cells in vivo and in vitro, enabling live-cell sorting for downstream analyses and live in vivo tracking. Our protocols are applicable to cellular systems, tissues, or animal models where senescence is present. For complete details on the use and execution of this protocol, please refer to Magkouta et al.1.

Functionalized ZnO-Based Nanocomposites for Diverse Biological Applications: Current Trends and Future Perspectives

The wide array of structures and characteristics found in ZnO-based nanostructures offers them a versatile range of uses. Over the past decade, significant attention has been drawn to the possible applications of these materials in the biomedical field, owing to their distinctive electronic, optical, catalytic, and antimicrobial attributes, alongside their exceptional biocompatibility and surface chemistry. With environmental degradation and an aging population contributing to escalating healthcare needs and costs, particularly in developing nations, there's a growing demand for more effective and affordable biomedical devices with innovative functionalities. This review delves into particular essential facets of different synthetic approaches (chemical and green) that contribute to the production of effective multifunctional nano-ZnO particles for biomedical applications. Outlining the conjugation of ZnO nanoparticles highlights the enhancement of biomedical capacity while lowering toxicity. Additionally, recent progress in the study of ZnO-based nano-biomaterials tailored for biomedical purposes is explored, including biosensing, bioimaging, tissue regeneration, drug delivery, as well as vaccines and immunotherapy. The final section focuses on nano-ZnO particles' toxicity mechanism with special emphasis to their neurotoxic potential, as well as the primary toxicity pathways, providing an overall review of the up-to-date development and future perspectives of nano-ZnO particles in the biomedicine field.

Structure-Based Evaluation of Hybrid Lipid-Polymer Nanoparticles: The Role of the Polymeric Guest

The combination of phospholipids and block-copolymers yields advanced hybrid nanoparticles through the self-assembly process in an aqueous environment. The physicochemical features of the lipid/polymer components, like the lipid-polymer molar ratio, the macromolecular architecture of the block copolymer, the main transition temperature of the phospholipid, as well as the formulation and preparation protocol parameters, are some of the most crucial parameters for the formation of hybrid lipid/polymer vesicles and for the differentiation of their morphology. The morphology, along with other physicochemical nanoparticle characteristics are strictly correlated with the nanoparticle's later biological behavior after being administered, affecting interactions with cells, biodistribution, uptake, toxicity, drug release, etc. In the present study, a structural evaluation of hybrid lipid-polymer nanoparticles based on cryo-TEM studies was undertaken. Different kinds of hybrid lipid-polymer nanoparticles were designed and developed using phospholipids and block copolymers with different preparation protocols. The structures obtained ranged from spherical vesicles to rod-shaped structures, worm-like micelles, and irregular morphologies. The obtained morphologies were correlated with the formulation and preparation parameters and especially the type of lipid, the polymeric guest, and their ratio.

Fabricating Polymer/Surfactant/Cyclodextrin Hybrid Particles for Possible Nose-to-Brain Delivery of Ropinirole Hydrochloride: In Vitro and Ex Vivo Evaluation

Ropinirole is a non-ergolinic dopamine agonist used to manage Parkinson's disease and it is characterized by poor oral bioavailability. This study aimed to design and develop advanced drug delivery systems composed of poloxamer 407, a non-ionic surfactant (Tween 80), and cyclodextrins (methyl-β-CD or hydroxy-propyl-β-CD) for possible brain targeting of ropinirole after nasal administration for the treatment of Parkinson's disease. The hybrid systems were formed by the thin-film hydration method, followed by an extensive physicochemical and morphological characterization. The in vitro cytotoxicity of the systems on HEK293 cell lines was also tested. In vitro release and ex vivo mucosal permeation of ropinirole were assessed using Franz cells at 34 °C and with phosphate buffer solution at pH 5.6 in the donor compartment, simulating the conditions of the nasal cavity. The results indicated that the diffusion-controlled drug release exhibited a progressive increase throughout the experiment, while a proof-of-concept experiment on ex vivo permeation through rabbit nasal mucosa revealed a better performance of the prepared hybrid systems in comparison to ropinirole solution. The encouraging results in drug release and mucosal permeation indicate that these hybrid systems can serve as attractive platforms for effective and targeted nose-to-brain delivery of ropinirole with a possible application in Parkinson's disease. Further ex vivo and in vivo studies to support the results of the present work are ongoing.

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.

A fluorophore-conjugated reagent enabling rapid detection, isolation and live tracking of senescent cells

Cellular senescence is a stress-response mechanism implicated in various physiological processes, diseases, and aging. Current detection approaches have partially addressed the issue of senescent cell identification in clinical specimens. Effective methodologies enabling precise isolation or live tracking of senescent cells are still lacking. In-depth analysis of truly senescent cells is, therefore, an extremely challenging task. We report (1) the synthesis and validation of a fluorophore-conjugated, Sudan Black-B analog (GLF16), suitable for in vivo and in vitro analysis of senescence by fluorescence microscopy and flow cytometry and (2) the development and application of a GLF16-carrying micelle vector facilitating GLF16 uptake by living senescent cells in vivo and in vitro. The compound and the applied methodology render isolation of senescent cells an easy, rapid, and precise process. Straightforward nanocarrier-mediated GLF16 delivery in live senescent cells comprises a unique tool for characterization of senescence at an unprecedented depth.

Marine-Originated Materials and Their Potential Use in Biomedicine

Aquatic habitats cover almost 70% of the Earth, containing several species contributing to marine biodiversity. Marine and aquatic organisms are rich in chemical compounds that can be widely used in biomedicine (dentistry, pharmacy, cosmetology, etc.) as alternative raw biomaterials or in food supplements. Their structural characteristics make them promising candidates for tissue engineering approaches in regenerative medicine. Thus, seaweeds, marine sponges, arthropods, cnidaria, mollusks, and the biomaterials provided by them, such as alginate, vitamins, laminarin, collagen, chitin, chitosan, gelatin, hydroxyapatite, biosilica, etc., are going to be discussed focusing on the biomedical applications of these marine-originated biomaterials. The ultimate goal is to highlight the sustainability of the use of these biomaterials instead of conventional ones, mainly due to the antimicrobial, anti-inflammatory, anti-aging and anticancer effect.

The Use of Crystalline Carbon-Based Nanomaterials (CBNs) in Various Biomedical Applications

This review study aims to present, in a condensed manner, the significance of the use of crystalline carbon-based nanomaterials in biomedical applications. Crystalline carbon-based nanomaterials, encompassing graphene, graphene oxide, reduced graphene oxide, carbon nanotubes, and graphene quantum dots, have emerged as promising materials for the development of medical devices in various biomedical applications. These materials possess inorganic semiconducting attributes combined with organic π-π stacking features, allowing them to efficiently interact with biomolecules and present enhanced light responses. By harnessing these unique properties, carbon-based nanomaterials offer promising opportunities for future advancements in biomedicine. Recent studies have focused on the development of these nanomaterials for targeted drug delivery, cancer treatment, and biosensors. The conjugation and modification of carbon-based nanomaterials have led to significant advancements in a plethora of therapies and have addressed limitations in preclinical biomedical applications. Furthermore, the wide-ranging therapeutic advantages of carbon nanotubes have been thoroughly examined in the context of biomedical applications.

Functional MOF-Based Materials for Environmental and Biomedical Applications: A Critical Review

Over the last ten years, there has been a growing interest in metal-organic frameworks (MOFs), which are a unique category of porous materials that combine organic and inorganic components. MOFs have garnered significant attention due to their highly favorable characteristics, such as environmentally friendly nature, enhanced surface area and pore volume, hierarchical arrangements, and adjustable properties, as well as their versatile applications in fields such as chemical engineering, materials science, and the environmental and biomedical sectors. This article centers on examining the advancements in using MOFs for environmental remediation purposes. Additionally, it discusses the latest developments in employing MOFs as potential tools for disease diagnosis and drug delivery across various ailments, including cancer, diabetes, neurological disorders, and ocular diseases. Firstly, a concise overview of MOF evolution and the synthetic techniques employed for creating MOFs are provided, presenting their advantages and limitations. Subsequently, the challenges, potential avenues, and perspectives for future advancements in the utilization of MOFs in the respective application domains are addressed. Lastly, a comprehensive comparison of the materials presently employed in these applications is conducted.

Chitosan-Based Nanoparticles for Nucleic Acid Delivery: Technological Aspects, Applications, and Future Perspectives

Chitosan is a naturally occurring polymer derived from the deacetylation of chitin, which is an abundant carbohydrate found mainly in the shells of various marine and terrestrial (micro)organisms. Chitosan has been extensively used to construct nanoparticles (NPs), which are biocompatible, biodegradable, non-toxic, easy to prepare, and can function as effective drug delivery systems. Moreover, chitosan NPs have been employed in gene and vaccine delivery, as well as advanced cancer therapy, and they can also serve as new therapeutic tools against viral infections. In this review, we summarize the most recent developments in the field of chitosan-based NPs intended as nucleic acid delivery vehicles and gene therapy vectors. Special attention is given to the technological aspects of chitosan complexes for nucleic acid delivery.

Design and Development of Low- and Medium-Viscosity Alginate Beads Loaded with Pluronic® F-127 Nanomicelles

The anionic polymer sodium alginate, a linear copolymer of guluronic and mannuronic acids, is primarily present in brown algae. Copolymers are used in the sodium alginate preparation process to confer on the material strength and flexibility. Micelles and other polymeric nanoparticles are frequently made using the triblock copolymer Pluronic^® F-127. The purpose of the present study is to determine the effect of sodium alginate's viscosity (low and medium) and the presence of Pluronic^® F-127 micelles on the swelling behavior of the prepared pure beads and those loaded with Pluronic^® F-127 micelles. The Pluronic^® F-127 nanomicelles have a size of 120 nm. The swelling studies were carried out at pH = 1.2 (simulated gastric fluid-SGF) for two hours and at pH = 6.8 (simulated intestinal fluid-SIF) for four more hours. The swelling of both low- and medium-viscosity alginate beads was minor at pH = 1.2, irrespective of the use of Pluronic^® F-127 nanomicelles. At pH = 6.8, without Pluronic^® F-127, the beads showed an enhanced swelling ratio for the first four hours, which was even higher in the medium-viscosity alginate beads. With the addition of Pluronic^® F-127, the beads were dissolved in the first and second hour, in the case of the low- and medium-alginate's viscosity, respectively. In other words, the behavior of the mixed hydrogels was the same during the swelling experiments. Therefore, the presence of Pluronic^® F-127 nanomicelles and medium-viscosity sodium alginate leads to a higher swelling ratio. A model drug, acetyl salicylic acid (ASA), was also encapsulated in the mixed beads and ASA's release studies were performed. In conclusion, the prepared systems, which are well characterized, show potential as delivery platforms for the oral delivery of active pharmaceutical ingredients and biopharmaceuticals.

Recent Advances in Nanoformulations for Quercetin Delivery

Quercetin (QUE) is a flavonol that has recently received great attention from the research community due to its important pharmacological properties. However, QUE's low solubility and extended first-pass metabolism limit its oral administration. This review aims to present the potential of various nanoformulations in the development of QUE dosage forms for bioavailability enhancement. Advanced drug delivery nanosystems can be used for more efficient encapsulation, targeting, and controlled release of QUE. An overview of the primary nanosystem categories, formulation processes, and characterization techniques are described. In particular, lipid-based nanocarriers, such as liposomes, nanostructured-lipid carries, and solid-lipid nanoparticles, are widely used to improve QUE's oral absorption and targeting, increase its antioxidant activity, and ensure sustained release. Moreover, polymer-based nanocarriers exhibit unique properties for the improvement of the Absorption, Distribution, Metabolism, Excretion, and Toxicology (ADME(T)) profile. Namely, micelles and hydrogels composed of natural or synthetic polymers have been applied in QUE formulations. Furthermore, cyclodextrin, niosomes, and nanoemulsions are proposed as formulation alternatives for administration via different routes. This comprehensive review provides insight into the role of advanced drug delivery nanosystems for the formulation and delivery of QUE.

The Role of Nano-Sensors in Breath Analysis for Early and Non-Invasive Disease Diagnosis

Early-stage, precise disease diagnosis and treatment has been a crucial topic of scientific discussion since time immemorial. When these factors are combined with experience and scientific knowledge, they can benefit not only the patient, but also, by extension, the entire health system. The development of rapidly growing novel technologies allows for accurate diagnosis and treatment of disease. Nanomedicine can contribute to exhaled breath analysis (EBA) for disease diagnosis, providing nanomaterials and improving sensing performance and detection sensitivity. Through EBA, gas-based nano-sensors might be applied for the detection of various essential diseases, since some of their metabolic products are detectable and measurable in the exhaled breath. The design and development of innovative nanomaterial-based sensor devices for the detection of specific biomarkers in breath samples has emerged as a promising research field for the non-invasive accurate diagnosis of several diseases. EBA would be an inexpensive and widely available commercial tool that could also be used as a disease self-test kit. Thus, it could guide patients to the proper specialty, bypassing those expensive tests, resulting, hence, in earlier diagnosis, treatment, and thus a better quality of life. In this review, some of the most prevalent types of sensors used in breath-sample analysis are presented in parallel with the common diseases that might be diagnosed through EBA, highlighting the impact of incorporating new technological achievements in the clinical routine.

Development of Hybrid DSPC:DOPC:P(OEGMA950-DIPAEMA) Nanostructures: The Random Architecture of Polymeric Guest as a Key Design Parameter

Hybrid nanoparticles have gained a lot of attention due to their advantageous properties and versatility in pharmaceutical applications. In this perspective, the formation of novel systems and the exploration of their characteristics not only from a physicochemical but also from a biophysical perspective could promote the development of new nanoplatforms with well-defined features. In the current work, lipid/copolymer bilayers were formed in different lipid to copolymer ratios and examined via differential scanning calorimetry as a preformulation study to decipher the interactions between the biomaterials, followed by nanostructure preparation by the thin-film hydration method. Physicochemical and toxicological evaluations were conducted utilizing light scattering techniques, fluorescence spectroscopy, and MTS assay. 1,2-dioctadecanoyl-sn-glycero-3-phosphocholine (DSPC) and 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) in different weight ratios were the chosen lipids, while a linear random copolymer with pH- and thermoresponsive properties comprised of oligo (ethylene glycol) methyl ether methacrylate (OEGMA) and 2-(diisopropylamino) ethyl methacrylate (DIPAEMA) in different ratios was used. According to our results, non-toxic hybrid nanosystems with stimuli-responsive properties were successfully formulated, and the main parameters influencing their overall performance were the hydrophilic/hydrophobic balance, lipid to polymer ratio, and more importantly the random copolymer topology. Hopefully, this investigation can promote a better understanding of the factors affecting the behavior of hybrid systems.

Recent Advances on PEO-PCL Block and Graft Copolymers as Nanocarriers for Drug Delivery Applications

Poly(ethylene oxide)-poly(ε-caprolactone) (PEO-PCL) is a family of block (or graft) copolymers with several biomedical applications. These types of copolymers are well-known for their good biocompatibility and biodegradability properties, being ideal for biomedical applications and for the formation of a variety of nanosystems intended for controlled drug release. The aim of this review is to present the applications and the properties of different nanocarriers derived from PEO-PCL block and graft copolymers. Micelles, polymeric nanoparticles, drug conjugates, nanocapsules, and hybrid polymer-lipid nanoparticles, such as hybrid liposomes, are the main categories of PEO-PCL based nanocarriers loaded with different active ingredients. The advantages and the limitations in preclinical studies are also discussed in depth. PEO-PCL based nanocarriers could be the next generation of delivery systems with fast clinical translation. Finally, current challenges and future perspectives of the PEO-PCL based nanocarriers are highlighted.

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.

Composite Nanoarchitectonics of Photoactivated Titania-Based Materials with Anticancer Properties

The synthesis of titania-based composite materials with anticancer potential under visible-light irradiation is the aim of this study. In specific, titanium dioxide (TiO₂) nanoparticles (NPs) chemically modified with silver were embedded in a stimuli-responsive microgel (a crosslinked interpenetrating network (IP) network that was synthesized by poly (N-Isopropylacrylamide) and linear chains of polyacrylic acid sodium salt, forming composite particles. The ultimate goal of this research, and for our future plans, is to develop a drug-delivery system that uses optical fibers that could efficiently photoactivate NPs, targeting cancer cells. The produced Ag-TiO₂ NPs, the microgel and the composite materials were characterized through X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), micro-Raman spectroscopy, ultraviolet-visible spectroscopy (UV-Vis), dynamic light scattering (DLS) and transmission electron microscopy (TEM). Our results indicated that Ag-TiO₂ NPs were successfully embedded within the thermoresponsive microgel. Either Ag-TiO₂ NPs or the composite materials exhibited high photocatalytic degradation efficiency on the pollutant rhodamine B and significant anticancer potential under visible-light irradiation.

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.

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.

Ag/Au Bimetallic Nanoparticles Trigger Different Cell Death Pathways and Affect Damage Associated Molecular Pattern Release in Human Cell Lines

Simple Summary

Apoptosis is the goal of several therapeutic strategies for cancer. However, the apoptotic pathway is not always functional in many cancers and thus, alternative ways to destroy cancer cells are required. In this context, we investigated whether nanoparticles composed of a gold and silver alloy (AgAu NPs) can induce other programmed cell death pathways. These include necroptosis and pyroptosis, while their effects on the release of molecules that serve as danger signals, the damage associated molecular patterns (DAMPs) were also investigated. Our findings suggest that MDA-MB-231 cells, one of the cancer cell lines tested, experience mixed cell death (several cell death pathways are activated), while a second cell line, HCT116 cells, releases DAMPS. This is important, since necroptosis and pyroptosis have promising anticancer effects, while DAMPs trigger inflammation and current knowledge suggests a rather beneficial role in cancer.

Abstract

Apoptosis induction is a common therapeutic approach. However, many cancer cells are resistant to apoptotic death and alternative cell death pathways including pyroptosis and necroptosis need to be triggered. At the same time, danger signals that include HMGB1 and HSP70 can be secreted/released by damaged cancer cells that boost antitumor immunity. We studied the cytotoxic effects of AgAu NPs, Ag NPs and Au NPs with regard to the programmed cell death (apoptosis, necroptosis, pyroptosis) and the secretion/release of HSP70 and HMGB1. Cancer cell lines were incubated with 30, 40 and 50 μg/mL of AgAu NPs, Ag NPs and Au NPs. Cytotoxicity was estimated using the MTS assay, and mRNA fold change of CASP1, CASP3, BCL-2, ZPB1, HMGB1, HSP70, CXCL8, CSF1, CCL20, NLRP3, IL-1β and IL-18 was used to investigate the associated programmed cell death. Extracellular levels of HMGB1 and IL-1β were investigated using the ELISA technique. The nanoparticles showed a dose dependent toxicity. Pyroptosis was triggered for LNCaP and MDA-MB-231 cells, and necroptosis for MDA-MB-231 cells. HCT116 cells experience apoptotic death and show increased levels of extracellular HMGB1. Our results suggest that in a manner dependent of the cellular microenvironment, AgAu NPs trigger mixed programmed cell death in P53 deficient MDA-MB-231 cells, while they also trigger IL-1β release in MDA-MB-231 and LNCaP cells and release of HMGB1 in HCT116 cells.

The technology of transdermal delivery nanosystems: from design and development to preclinical studies

Transdermal administration has gained much attention due to the remarkable advantages such as patient compliance, drug escape from first-pass elimination, favorable pharmacokinetic profile and prolonged release properties. However, the major limitation of these systems is the limited skin penetration of the stratum corneum, the skin's most important barrier, which protects the body from the insertion of substances from the environment. Transdermal drug delivery systems are aiming to the disruption of the stratum corneum in order for the active pharmaceutical ingredients to enter successfully the circulation. Therefore, nanoparticles are holding a great promise because they can act as effective penetration enhancers due to their small size and other physicochemical properties that will be analyzed thoroughly in this report. Apart from the investigation of the physicochemical parameters, a comparison between the different types of nanoparticles will be performed. The complexity of skin anatomy and the unclear mechanisms of penetration should be taken into consideration to reach some realistic conclusions regarding the way that the described parameters affect the skin permeability. To the best of the authors knowledge, this is among the few reports on the literature describing the technology of transdermal delivery systems and how this technology affects the biological activity.

Thermoresponsive chimeric nanocarriers as drug delivery systems

Chimeric or mixed nanosystems belong to the class of advanced therapeutics. Their distinctive characteristic compared with other types of nanoparticles is that they combine two or more different classes of biomaterials. These platforms have created a promising and versatile field of nanomedicine, incorporating materials that are biocompatible, such as lipids, but also functional, such as stimuli-responsive polymers. In the present work, thermoresponsive chimeric nanocarriers composed of l-α-phosphatidylcholine (Egg, Chicken) (EPC) phospholipids and poly(N-isopropylacrylamide)-b-poly(lauryl acrylate) (PNIPAM-b-PLA) block copolymers were designed and developed. Initially, model lipid bilayers with incorporated polymers and drug molecule TRAM-34 were built and studied for their thermodynamics, in order to assess the stability and functionality of the systems. Chimeric nanoparticles of EPC and PNIPAM-b-PLA were then developed and evaluated for their physicochemical properties in different medium conditions, as well as for their morphology. Polymer incorporation led to alterations in the properties and morphology of the nanoparticles, while interactions with serum proteins were absent. TRAM-34 was also incorporated inside the developed nanocarriers, followed by incorporation and release studies, which revealed the functionality of the system in elevated temperature conditions. Finally, in vitro studies on normal cells suggest the biocompatibility of these nanosystems. The proposed platforms are promising for further studies and applications in vitro and in vivo.

Chimeric Stimuli-Responsive Liposomes as Nanocarriers for the Delivery of the Anti-Glioma Agent TRAM-34

Nanocarriers are delivery platforms of drugs, peptides, nucleic acids and other therapeutic molecules that are indicated for severe human diseases. Gliomas are the most frequent type of brain tumor, with glioblastoma being the most common and malignant type. The current state of glioma treatment requires innovative approaches that will lead to efficient and safe therapies. Advanced nanosystems and stimuli-responsive materials are available and well-studied technologies that may contribute to this effort. The present study deals with the development of functional chimeric nanocarriers composed of a phospholipid and a diblock copolymer, for the incorporation, delivery and pH-responsive release of the antiglioma agent TRAM-34 inside glioblastoma cells. Nanocarrier analysis included light scattering, protein incubation and electron microscopy, and fluorescence anisotropy and thermal analysis techniques were also applied. Biological assays were carried out in order to evaluate the nanocarrier nanotoxicity in vitro and in vivo, as well as to evaluate antiglioma activity. The nanosystems were able to successfully manifest functional properties under pH conditions, and their biocompatibility and cellular internalization were also evident. The chimeric nanoplatforms presented herein have shown promise for biomedical applications so far and should be further studied in terms of their ability to deliver TRAM-34 and other therapeutic molecules to glioblastoma cells.

Lamellarity and size distributions in mixed DPPC/amphiphilic poly(2-oxazoline) gradient copolymer vesicles and their temperature response

Mixed liposomes of dipalmitoylphosphatidylcholine (DPPC) and gradient (pseudodiblock) poly(2-methyl-2-oxazoline)-grad-poly(2-phenyl-2-oxazoline) (MPOx) copolymers are investigated by small angle neutron scattering (SANS). All experimental data, from different phospholipid-copolymer compositions, concentrations and temperatures are fitted with one model. This model allows the determination of the separate contributions from vesicular populations of different lamellarity and size. MPOx copolymers are proved to modify both the size and lamellarity of DPPC liposomes. The gradient copolymer with higher hydrophilic content induces shrinkage of the uni- and bi-lamellar DPPC vesicles. The copolymer with lower hydrophilic content causes dramatic changes on the lamellarity of DPPC vesicles by the formation of hexa-lamellar vesicles. The tendency of multi-lamellar vesicles to transform into uni-lamellar ones as temperature increases is more pronounced in the presence of the copolymers. These findings may have direct implications on the drug loading and release properties of liposomes and their interactions with cells.

A Novel, Nontoxic and Scalable Process to Produce Lipidic Vehicles

Lipidic vehicles are novel industrial products, utilized as components for pharmaceutical, cosmeceutical and nutraceutical formulations. The present study concerns a newly invented method to produce lipidic vehicles in the nanoscale that is simple, nontoxic, versatile, time-efficient, low-cost and easy to scale up. The process is a modification of the heating method (MHM) and comprises (i) providing a mixture of an amphiphilic lipid and a charged lipid and/or a fluidity regulator in a liquid medium composed of water and a liquid polyol, (ii) stirring and heating the mixture in two heating steps, wherein the temperature of the second step is higher than the temperature of the first step and (iii) allowing the mixture to cool down to room temperature. The process leads to the self-assembly of nanoparticles of small size and good homogeneity, compared with conventional approaches that require additional size reduction steps. In addition, the incorporation of bioactive molecules, such as drugs, inside the nanoparticles is possible, while lyophilization of the products provides long-term stability. Most importantly, the absence of toxic solvents and the simplicity guarantee the safety and scalability of the process, distinguishing it from most prior art processes to produce of lipidic vehicles.

Nanomedicines and Nanosimilars: Looking for a New and Dynamic Regulatory "Astrolabe" Inspired System

The application of the nanotechnology in medicine and pharmaceutics opens new horizons in therapeutics. Several nanomedicines are in the market and an increasing number is in clinical trials. But which is the advantage of the medicines in nanoscale? The scientists and the regulatory authorities agree that the size and consequently the physiochemical/biological properties of nanomaterials play a key role in their safety and effectiveness. Additionally, all of them agree that a new scientific-based regulatory landscape is required for the establishment of nanomedicines in the market. The aim of this review is to investigate the parameters that the scientists and the regulatory authorities should take into account in order to build up a dynamic regulatory landscape for nanomedicines. For this reason, we propose an "astrolabe-like system" as the guide for establishing the regulatory approval process. Its function is based on the different physicochemical/biological properties in comparison to low molecular weight drugs.

Preparation and physicochemical characterization of elastic liposomes: a road-map library for their design

Elastic liposomes consist of phospholipids and of surfactants, could be considered as promising nanotechnological platforms for skin drug delivery. The aim of the present study was the formation of elastic liposomes by thin film hydration method, using different phospholipids and surfactants, in order to determine the effect of the components on their physical characteristics and on their physical stability. Physical properties of elastic liposomes were evaluated using dynamic light scattering (DLS)method. The particle size at the day of their preparation, was ranged between small and large unilamellar vesicles (SUVs and LUVs), dependent on the hydrophilicity of the surfactant used, while their PDI (Poly Dispersity Index) value was close to zero, indicating monodispersed systems. Physical stability study involved the measure of particle size, as a quantifiable physical property, at selected times over a 30-days period, at storage conditions: (i) 4 °C, (ii) 25 °C, iii) 45 °C, suggested that refrigerated conditions promote physical stability, while high temperatures induce aggregation. According to the physical stability study elastic liposomes composed ofTween80 were found to bemore stable than those composed of Span80, at ambient conditions. The goal of our investigation was centred to the development and evaluation of a well know liposomal category i.e. elastic liposomes, by modified their composition with common surfactants (i.e. Span and/or Tween), creating, a new liposomal class namely, elastic lipo-niosomes. To the best of knowledge this the first time that these hybrid vesicles appeared in the literature exhibiting the aforementioned category lipid/surfactants and molar ratios.

Stimuli-Responsive Lyotropic Liquid Crystalline Nanosystems with Incorporated Poly(2-Dimethylamino Ethyl Methacrylate)-b-Poly(Lauryl Methacrylate) Amphiphilic Block Copolymer

There is an emerging need to evolve the conventional lyotropic liquid crystalline nanoparticles to advanced stimuli-responsive, therapeutic nanosystems with upgraded functionality. Towards this effort, typically used stabilizers, such as Pluronics^®, can be combined or replaced by smart, stimuli-responsive block copolymers. The aim of this study is to incorporate the stimuli-responsive amphiphilic block copolymer poly(2-(dimethylamino)ethyl methacrylate)-b-poly(lauryl methacrylate) (PDMAEMA-b-PLMA) as a stabilizer in lipidic liquid crystalline nanoparticles, in order to provide steric stabilization and simultaneous stimuli-responsiveness. The physicochemical and morphological characteristics of the prepared nanosystems were investigated by light scattering techniques, cryogenic-transmission electron microscopy (cryo-TEM), X-ray diffraction (XRD) and fluorescence spectroscopy. The PDMAEMA-b-PLMA, either individually or combined with Poloxamer 407, exhibited different modes of stabilization depending on the lipid used. Due to the protonation ability of PDMAEMA blocks in acidic pH, the nanoparticles exhibited high positive charge, as well as pH-responsive charge conversion, which can be exploited towards pharmaceutical applications. The ionic strength, temperature and serum proteins influenced the physicochemical behavior of the nanoparticles, while the polymer concentration differentiated their morphology; their micropolarity and microfluidity were also evaluated. The proposed liquid crystalline nanosystems can be considered as novel and attractive pH-responsive drug and gene delivery nanocarriers due to their polycationic content.

Carbon nanohorn/liposome systems: Preformulation, design and in vitro toxicity studies

In the present work, the convergence of two different drug delivery systems is investigated, namely the combination of carbon nanohorns (CNHs) and liposomes. Our effort initially included the synthesis of two conversely charged carbon nanohorns and their subsequent analysis through various methods. The study of their effect on the thermotropic behavior of artificial membranes provided an essential assistance for the upcoming liposome preparation, which were estimated for their physicochemical properties. The presence of CNHs alters the calorimetric parameters of the lipids. We also prepared CNHs:liposome systems. The characteristic morphology and secondary spherical superstructure of CNHs is retained in the chimeric materials, suggesting that the interactions with the liposomes do not alter the dahlia-flower-like aggregation of CNHs. Both CNHs-liposome systems exhibit a relatively small cellular cytotoxicity in vitro, tested in mouse embryonic fibroblasts. To summarize, we developed CNHs:liposome platforms with a complete knowledge of their thermotropic, physicochemical, morphological and nanotoxicological characteristics.

Incorporation of PEGylated δ-decalactone into lipid bilayers: thermodynamic study and chimeric liposomes development

Liposomes have been on the market as drug delivery systems for over 25 years. Their success comes from the ability to carry toxic drug molecules to the appropriate site of action through passive accumulation, thus reducing their severe side effects. However, the need for enhanced circulation time and site and time-specific drug delivery turned research focus on other systems, such as polymers. In this context, novel composites that combine the flexibility of polymeric nanosystems with the properties of liposomes gained a lot of interest. In the present work a mixed/chimeric liposomal system, composed of phospholipids and block copolymers, was developed and evaluated in regards with its feasibility as a drug delivery system. These innovative nano-platforms combine advantages from both classes of biomaterials. Thermal analysis was performed in order to offers an insight into the interactions between these materials and consequently into their physicochemical characteristics. In addition, colloidal stability was assessed by monitoring z-potential and size distribution over time. Finally, their suitability as carriers for biomedical applications was evaluated by carrying out in vitro toxicity studies.

PEO-b-PCL grafted niosomes: The cooperativilty of amphiphilic components and their properties in vitro and in vivo

Niosomes belong to drug delivery systems and consist mainly of non-ionic surfactants and cholesterol. In this study, we designed and developed systems composed of non-ionic surfactants i.e. Tween 80, Span 80 and cholesterol with and without poly(ethylene oxide)-b-poly(ε-caprolactone) (PEO-b-PCL) block copolymer, using different molar ratios of the above components. The nanosystems were formed by the thin-film hydration method with purified water as dispersion medium. Several physicochemical techniques were utilized in order to study the physicochemical and morphological characteristics of the prepared assemblies. The results showed that the presence of the block copolymer alters significantly the size and morphology of neat surfactant/cholesterol niosomes. The ageing studies also revealed that the stability is strongly dependent on the nature and the molar ratios of the components. Moreover, neither of the studied nanosystems exhibited elevated signs of cellular toxicity in vitro nor acute systemic toxicity in vivo short-term experiments. This investigation covers a new field of drug delivery platforms those of niosomes composed by different biomaterials i.e. surfactants and block copolymers.

Development and Evaluation of Stimuli-Responsive Chimeric Nanostructures

Chimeric/mixed stimuli-responsive nanocarriers are promising agents for therapeutic and diagnostic applications, as well as in the combinatorial field of theranostics. Herein, we designed chimeric nanosystems, composed of natural phospholipid and pH-sensitive amphiphilic diblock copolymer, in different molar ratios and assessed the polymer lyotropic effect on their properties. Initially, polymer-grafted bilayers were evaluated for their thermotropic behavior by thermal analysis. Chimeric liposomes were prepared through thin-film hydration and the obtained vesicles were studied by light scattering techniques, to measure their physicochemical characteristics and colloidal stability, as well as by imaging techniques, to elucidate their global and membrane morphology. Finally, in vitro screening of the systems' toxicity was held. The copolymer effect on the membrane phase transition strongly depended on the pH of the surrounding environment. Chimeric nanoparticles were around and above 100 nm, while electron microscopy revealed occasional morphology diversity, probably affecting the toxicity of the systems. The latter was assessed to be tolerable, while dependent on the nanosystems' material concentration, polymer concentration, and polymer composition. All experiments suggested that the thermodynamic and biophysical properties of the nanosystems are copolymer-composition- and concentration-dependent, since different amounts of incorporated polymer would produce divergent effects on the lyotropic liquid crystal membrane. Certain chimeric systems can be exploited as advanced drug delivery nanosystems, based on their overall promising profiles.

Cubic lyotropic liquid crystals as drug delivery carriers: Physicochemical and morphological studies

The self-assembly process of amphiphilic molecules into solvents results in different mesophases, such as inverse cubic and hexagonal that both belong to the wider category of lyotropic liquid crystals. The above mesophases can be further exploited upon the formation of liquid crystalline nanoparticles, cubosomes and hexosomes respectively, which may be utilized as drug delivery nanosystems, exhibiting major advantages. In the present study, liquid crystalline nanoparticles were prepared and evaluated in terms of morphology and physicochemical behavior. The goal of this study is to examine the effect of the different formulation parameters, as well as the effect of the different microenvironmental factors (temperature, ionic strength, pH, serum proteins presence) on their behavior. The physicochemical behavior and the morphology of the systems were investigated by X-Ray Diffraction (XRD), cryogenic-Transmission Electron Microscopy (cryo-TEM), fluorescence spectroscopy and a gamut of light scattering techniques. The formulation process was proved to influence strictly the physicochemical behavior of the prepared nanosystems. They presented colloidal stability over time and upon ionic strength increase, but they were affected by the presence of proteins and presented reversible structure alterations upon temperature increase. Their morphological structure and internal microenvironment, reflected by micropolarity and microfluidity, were also influenced by the formulation parameters.

Marine sulfated polysaccharides as versatile polyelectrolytes for the development of drug delivery nanoplatforms: Complexation of ulvan with lysozyme

Ulvan, a marine sulfated polysaccharide isolated from green algae, has been recently recognized as a natural biopolymer of biomedical interest. A series of lysozyme/ulvan complexes prepared under various charge ratios at physiological pH were studied. The resulting complexes were examined with light scattering techniques in order to characterize the size, the distribution and the ζ-potential of the nanocarriers, which were found to depend on the charge ratio employed. Increased complexation efficiency of lysozyme was observed for certain charge ratios, while ATR-FTIR data suggested that the protein structure after complexation was retained. Bacterial growth studies showed that lysozyme once complexed with ulvan not only retains its antibacterial activity against the Gram positive strain Staphylococcus aureus, but actually exhibits increased levels of activity. In this model study, the results highlight the potential of ulvan as a promising nanocarrier for positively charged bioactive molecules.

Polymer Self-Assembled Nanostructures as Innovative Drug Nanocarrier Platforms

BACKGROUND

Polymer self-assembled nanostructures are used in pharmaceutical sciences as bioactive molecules' delivery systems for therapeutic and diagnostic purposes. Micelles, polyelectrolyte complexes, polymersomes, polymeric nanoparticles, nanogels and polymer grafted liposomes represent delivery vehicles that are marketed and/or under clinical development, as drug formulations.

METHODS

In this mini-review, these, recently appeared in the literature, innovative polymer drug nanocarrier platforms are discussed, starting from their technological development in the laboratory to their potential clinical use, through studies of their biophysics, thermodynamics, physical behavior, morphology, bio-mimicry, therapeutic efficacy and safety. The properties of an ideal drug delivery system are the structural control over size and shape of drug or imaging agent cargo/domain, biocompatibility, nontoxic polymer/ pendant functionality and the precise, nanoscale container and/or scaffolding properties with high drug or imaging agent capacity features. Self-assembled polymer nanostructures exhibit all these properties and could be considered as ideal drug nanocarriers through control of their size, structure and morphology, with the aid of a large variety of parameters, in vitro and in vivo. These modern trends reside at the interface of soft matter self-assembly and pharmaceutical sciences and the technologies for health.

CONCLUSION

Great advantages related to basic science and applications are expected by understanding the self-assembly behavior of these polymeric nanotechnological drug delivery systems, created through bio-inspiration and biomimicry and have potential utilization into clinical applications.

Liposomes in Polymersomes: Multicompartment System with Temperature-Triggered Release

Multicompartmentalization is a key feature of eukaryotic cells, allowing separation and protection of species within the membrane walls. During the last years, several methods have been reported to afford synthetic multicompartment lipidic or polymeric vesicles that mimic biological cells and that allow cascade chemical or enzymatic reactions within their lumen. We hereby report on the preparation and study of liposomes in polymersomes (LiPs) systems. We discuss on the loading and coloading of lipidic nanovesicles made of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), 1,2-dipentadecanoyl-sn-glycero-3-phosphocholine (diC15-PC), or 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) inside the lumen of giant poly(butadiene)-b-poly(ethylene oxide) (PBut-b-PEO) polymersomes. These LiPs systems were characterized by confocal microscopy and UV-visible spectroscopy. We further demonstrate that we can achieve controlled sequential release of dyes from diC15-PC and DPPC liposomes at defined temperatures inside the giant PBut-b-PEO polymersomes. This controlled release could be used as a means to initiate cascade reactions on demand in confined microreactors.

Design and development of pH-responsive HSPC:C12H25-PAA chimeric liposomes

The application of stimuli-responsive medical practices has emerged, in which pH-sensitive liposomes figure prominently. This study investigates the impact of the incorporation of different amounts of pH-sensitive polymer, C12H25-PAA (poly(acrylic acid) with a hydrophobic end group) in l-α-phosphatidylcholine, hydrogenated (Soy) (HSPC) phospholipidic bilayers, with respect to biomimicry and functionality. PAA is a poly(carboxylic acid) molecule, classified as a pH-sensitive polymer, whose pH-sensitivity is attributed to its regulative -COOH groups, which are protonated under acidic pH (pKa ∼4.2). Our concern was to fully characterize, in a biophysical and thermodynamical manner, the mixed nanoassemblies arising from the combination of the two biomaterials. At first, we quantified the physicochemical characteristics and physical stability of the prepared chimeric nanosystems. Then, we studied their thermotropic behavior, through measurement of thermodynamical parameters, using Differential Scanning Calorimetry (DSC). Finally, the loading and release of indomethacin (IND) were evaluated, as well as the physicochemical properties and stability of the nanocarriers incorporating it. As expected, thermodynamical findings are in line with physicochemical results and also explain the loading and release profiles of IND. The novelty of this investigation is the utilization of these pH-sensitive chimeric advanced Drug Delivery nano Systems (aDDnSs) in targeted drug delivery which relies entirely on the biophysics and thermodynamics between such designs and the physiological membranes and environment of living organisms.

Efficacy of a New Heparan Sulfate Mimetic Dressing in the Healing of Foot and Lower Extremity Ulcerations in Type 2 Diabetes: A Case Series

A novel heparan sulfate glycosaminoglycan mimetic product for local application to promote wound healing (CACIPLIQ) has recently become available. It is a biophysical therapeutic product comprising a polysaccharide as an innovative biomaterial to accomplish mechanical tissue engineering and skin regeneration in the site of ulceration. We present a series of 12 patients with type 2 diabetes (4 men and 8 women; age 53-87 years; diabetes duration 8-25 years) having chronic resistance to therapy for foot and lower extremity ulcerations. CACIPLIQ was locally applied twice per week after careful debridement. Complete ulcer healing was accomplished in all patients after a mean treatment duration of 4.92 months (range = 2-12 months). The product was very well tolerated. In conclusion, these results, although preliminary, are encouraging and suggest adequate efficacy and safety of the new product in difficult-to-heal foot and lower extremity ulcerations in type 2 diabetes.