Self-Assembled Polymersomes Conjugated with Lactoferrin as Novel Drug Carrier for Brain Delivery

Ring-opening polymerization of emulsion-templated deep eutectic system monomer for macroporous polyesters with controlled degradability

Biodegradable polyesters with interconnected macroporosity, such as poly(l-lactide) (PLLA) and poly(ε-caprolactone) (PCL), have gained significant importance in the fields of tissue engineering and separation. This study introduces functional macroinitiators, specifically polycaprolactone triol (PCLT) and polyethylene glycol (PEG), both OH-terminated, in the solventless ring-opening polymerization (ROP) of a liquid deep eutectic system monomer (DESm) composed of LLA and CL at a 30 : 70 molar ratio, respectively. The macroinitiators selectively initiate the organocatalyzed ROP of LLA in the DESm during the first polymerization stage, thereby modifying the PLLA architecture. This results in the formation of either branched or linear PLLA copolymers depending on the macroinitiator, PCLT and PEG, respectively. In the second stage, the ROP of the CL, which is a counterpart of the DESm, produces PCL that blends with the previously formed PLLA. The insights gained into the PLLA architectures during the first stage of the DESm ROP, along with the overall molecular weight and hydrophobicity of the resulting PLLA/PCL blend in bulk, were advantageously used to design polymerizable high internal phase emulsions (HIPEs) oil-in-DESm. By incorporating a liquid mixture of DESm and macroinitiators (PCLT or PEG), stable HIPE formulations were achieved. These emulsions sustained the efficient organocatalyzed ROP of the continuous phase at 37 °C with high conversions. The resulting polymer replicas of the HIPEs, characterized by macroporous and interconnected structures, were subjected to a degradation assay in PBS at pH 7.4 and 37 °C and remained mechanically stable for at least 30 days. Notably, they exhibited the capability to sorb crude oil in a proof-of-concept test, with a rate of 2 g g-1. The macroporous and interconnected features of the polyHIPEs, combined with their inherent degradation properties, position them as promising degradable polymeric sorbents for efficient separation of hydrophobic fluids from water.

Development of lactoferrin-coated multifunctional copolymer micelles to cross the blood-brain barrier

The blood-brain barrier (BBB) prevents pathogens and toxins in the bloodstream from reaching the brain, but also inhibits the delivery of agents intended to treat central nervous system disorders, such as Alzheimer's disease (AD). In this study, we prepared and evaluated a novel nano-delivery vehicle system composed of lactoferrin-conjugated (Lf-PIC@Se) micelles. We used a COOH-PEG-PAsp-PV@Se synthesis-based method to prepare the micelles, which involved self-assembly followed by EDC-NHS coupling. Using glutaminyl cyclase inhibitor 8 as a model encapsulated chemical, Lf-PIC@Se micelles achieved a good loading capacity. In vitro analysis demonstrated that Lf-PIC@Se/8 micelles were stable in both neutral and acidic pH solutions in the presence or absence of H2O2, and confirmed their biosafety and compatibility in PC12 and bEND.3 cells. Notably, the cell uptake of Lf-PIC@Se/C6 micelles was much higher than that of PIC@Se micelles, and occurred through LfR-mediated endocytosis. The presence of Se meant that Lf-PIC@Se micelles acted as ROS scavengers in PC12 cells under H2O2-induced oxidative stress, which inhibited oxidative damage and increased mitochondrial membrane potential. Hemolysis assays further demonstrated that Lf-PIC@Se represent a biocompatible carrier. Finally, in vivo experiments in mice suggested that Lf-PIC@Se micelles successfully crossed the BBB, confirming their potential as vehicles for drug delivery when treating AD and other central nervous system disorders.

Biomaterials-based anti-inflammatory treatment strategies for Alzheimer's disease

The current therapeutic drugs for Alzheimer's disease only improve symptoms, they do not delay disease progression. Therefore, there is an urgent need for new effective drugs. The underlying pathogenic factors of Alzheimer's disease are not clear, but neuroinflammation can link various hypotheses of Alzheimer's disease; hence, targeting neuroinflammation may be a new hope for Alzheimer's disease treatment. Inhibiting inflammation can restore neuronal function, promote neuroregeneration, reduce the pathological burden of Alzheimer's disease, and improve or even reverse symptoms of Alzheimer's disease. This review focuses on the relationship between inflammation and various pathological hypotheses of Alzheimer's disease; reports the mechanisms and characteristics of small-molecule drugs (e.g., nonsteroidal anti-inflammatory drugs, neurosteroids, and plant extracts); macromolecule drugs (e.g., peptides, proteins, and gene therapeutics); and nanocarriers (e.g., lipid-based nanoparticles, polymeric nanoparticles, nanoemulsions, and inorganic nanoparticles) in the treatment of Alzheimer's disease. The review also makes recommendations for the prospective development of anti-inflammatory strategies based on nanocarriers for the treatment of Alzheimer's disease.

Enhancing paracellular and transcellular permeability using nanotechnological approaches for the treatment of brain and retinal diseases

Paracellular permeability across epithelial and endothelial cells is, in large part, regulated by apical intercellular junctions also referred to as tight junctions (TJs). These junctions contribute to the spatial definition of different tissue compartments within organisms, separating them from the outside world as well as from inner compartments, with their primary physiological role of maintaining tissue homeostasis. TJs restrict the free, passive diffusion of ions and hydrophilic small molecules through paracellular clefts and are important for appropriate cell polarization and transporter protein localisation, supporting the controlled transcellular diffusion of smaller and larger hydrophilic as well as hydrophobic substances. This traditional diffusion barrier concept of TJs has been challenged lately, owing to a better understanding of the components that are associated with TJs. It is now well-established that mutations in TJ proteins are associated with a range of human diseases and that a change in the membrane fluidity of neighbouring cells can open possibilities for therapeutics to cross intercellular junctions. Nanotechnological approaches, exploiting ultrasound or hyperosmotic agents and permeation enhancers, are the paradigm for achieving enhanced paracellular diffusion. The other widely used transport route of drugs is via transcellular transport, allowing the passage of a variety of pro-drugs and nanoparticle-encapsulated drugs via different mechanisms based on receptors and others. For a long time, there was an expectation that lipidic nanocarriers and polymeric nanostructures could revolutionize the field for the delivery of RNA and protein-based therapeutics across different biological barriers equipped with TJs (e.g., blood-brain barrier (BBB), retina-blood barrier (RBB), corneal TJs, etc.). However, only a limited increase in therapeutic efficiency has been reported for most systems until now. The purpose of this review is to explore the reasons behind the current failures and to examine the emergence of synthetic and cell-derived nanomaterials and nanotechnological approaches as potential game-changers in enhancing drug delivery to target locations both at and across TJs using innovative concepts. Specifically, we will focus on recent advancements in various nanotechnological strategies enabling the bypassing or temporally opening of TJs to the brain and to the retina, and discuss their advantages and limitations.

Neuroprotective Action of Humanin and Humanin Analogues: Research Findings and Perspectives

Humanin is a 24-mer peptide first reported in the early 2000s as a new neuroprotective/cytoprotective factor rescuing neuronal cells from death induced by various Alzheimer's disease-associated insults. Nowadays it is known that humanin belongs to the novel class of the so-called mitochondrial-derived peptides (which are encoded by mitochondrial DNA) and has been shown to exert beneficial cytoprotective effects in a series of in vitro and/or in vivo experimental models of human diseases, including not only neurodegenerative disorders but other human diseases as well (e.g., age-related macular degeneration, cardiovascular diseases, or diabetes mellitus). This review article is focused on the presentation of recent in vitro and in vivo research results associated with the neuroprotective action of humanin as well as of various, mainly synthetic, analogues of the peptide; moreover, the main mode(s)/mechanism(s) through which humanin and humanin analogues may exert in vitro and in vivo regarding neuroprotection have been reported. The prospects of humanin and humanin analogues to be further investigated in the frame of future research endeavors against neurodegenerative/neural diseases have also been briefly discussed.

Intracerebral Nanoparticle Transport Facilitated by Alzheimer Pathology and Age

Nanoparticles have emerged as potential transporters of drugs targeting Alzheimer's disease (AD), but their design should consider the blood-brain barrier (BBB) integrity and neuroinflammation of the AD brain. This study presents that aging is a significant factor for the brain localization and retention of nanoparticles, which we engineered to bind with reactive astrocytes and activated microglia. We assembled 200 nm-diameter particles using a block copolymer of poly(lactic-co-glycolic acid) (PLGA) and CD44-binding hyaluronic acid (HA). The resulting PLGA-b-HA nanoparticles displayed increased binding to CD44-expressing reactive astrocytes and activated microglia. Upon intravascular injection, nanoparticles were localized to the hippocampi of both APP/PS1 AD model mice and their control littermates at 13-16 months of age due to enhanced transvascular transport through the leaky BBB. No particles were found in the hippocampi of young adult mice. These findings demonstrate the brain localization of nanoparticles due to aging-induced BBB breakdown regardless of AD pathology.

Preparation and Catalytic Properties of Carbonic Anhydrase Conjugated to Liposomes through a Bis-Aryl Hydrazone Bond

Liposomes (lipid vesicles) with sizes of about 100-200 nm carrying surface-bound (immobilized) water-soluble enzymes are functionalized molecular compartment systems for possible applications, for example, as therapeutic materials or as catalytic reaction units for running reactions in aqueous media in vitro. One way of covalently attaching enzyme molecules under mild conditions in a controlled way to the surface of preformed liposomes is to apply the spectrophotometrically traceable bis-aryl hydrazone (BAH) bond between the liposome and the enzyme molecules of interest. Using bovine carbonic anhydrase (BCA), an aqueous dispersion of liposome-BAH-BCA - conjugates of defined composition was prepared. The liposomes used consisted of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), N-(methylpolyoxyethylene oxycarbonyl)-1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE-PEG), and N-(aminopropylpolyoxyethylene oxycarbonyl)-1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE-PEG-NH₂). The amino group of some of the DSPE-PEG-NH₂ molecules present in the liposomes were converted into an aromatic aldehyde, which (after purification) reacted with (purified) BCA molecules that had on their surface on average one acetone protected aromatic hydrazine. After purification of the liposome-BAH-BCA conjugate dispersion obtained, it was characterized in terms of (i) BCA activity, (ii) overall BCA structure, and (iii) storage stability. For an average liposome of 138 nm diameter, about 1200 BCA molecules were attached to the outer liposome surface. Liposomally bound BCA was found to exhibit (i) similar catalytic activity at 25 °C and (ii) similar storage stability when stored in a dispersed state in aqueous solution at 4 °C as free BCA. Measurements at 5 °C clearly showed that liposome-BAH-BCA is able to catalyze the hydration of carbon dioxide to hydrogen carbonate.

Lactoferrin as a Component of Pharmaceutical Preparations: An Experimental Focus

Lactoferrin is an 80 kDa monomeric glycoprotein that exhibits multitask activities. Lactoferrin properties are of interest in the pharmaceutical field for the design of products with therapeutic potential, including nanoparticles and liposomes, among many others. In antimicrobial preparations, lactoferrin has been included either as a main bioactive component or as an enhancer of the activity and potency of first-line antibiotics. In some proposals based on nanoparticles, lactoferrin has been included in delivery systems to transport and protect drugs from enzymatic degradation in the intestine, favoring the bioavailability for the treatment of inflammatory bowel disease and colon cancer. Moreover, nanoparticles loaded with lactoferrin have been formulated as delivery systems to transport drugs for neurodegenerative diseases, which cannot cross the blood-brain barrier to enter the central nervous system. This manuscript is focused on pharmaceutical products either containing lactoferrin as the bioactive component or formulated with lactoferrin as the carrier considering its interaction with receptors expressed in tissues as targets of drugs delivered via parenteral or mucosal administration. We hope that this manuscript provides insights about the therapeutic possibilities of pharmaceutical Lf preparations with a sustainable approach that contributes to decreasing the resistance of antimicrobials and enhancing the bioavailability of first-line drugs for intestinal chronic inflammation and neurodegenerative diseases.

Polymersome-based protein drug delivery - quo vadis?

Protein-based therapeutics are an attractive alternative to established therapeutic approaches and represent one of the fastest growing families of drugs. While many of these proteins can be delivered using established formulations, the intrinsic sensitivity of proteins to denaturation sometimes calls for a protective carrier to allow administration. Historically, lipid-based self-assembled structures, notably liposomes, have performed this function. After the discovery of polymersome-based targeted drug-delivery systems, which offer manifold advantages over lipid-based structures, the scientific community expected that such systems would take the therapeutic world by storm. However, no polymersome formulations have been commercialised. In this review article, we discuss key obstacles for the sluggish translation of polymersome-based protein nanocarriers into approved pharmaceuticals, which include limitations imparted by the use of non-degradable polymers, the intricacies of polymersome production methods, and the complexity of the in vivo journey of polymersomes across various biological barriers. Considering this complex subject from a polymer chemist's point of view, we highlight key areas that are worthy to explore in order to advance polymersomes to a level at which clinical trials become worthwhile and translation into pharmaceutical and nanomedical applications is realistic.

Brain drug delivery and neurodegenerative diseases: Polymeric PLGA-based nanoparticles as a forefront platform

The discovery of effective drugs for the treatment of neurodegenerative disorders (NDs) is a deadlock. Due to their complex etiology and high heterogeneity, progresses in the development of novel NDs therapies have been slow, raising social/economic and medical concerns. Nanotechnology and nanomedicine evolved exponentially in recent years and presented a panoply of tools projected to improve diagnosis and treatment. Drug-loaded nanosystems, particularly nanoparticles (NPs), were successfully used to address numerous drug glitches, such as efficacy, bioavailability and safety. Polymeric nanoparticles (PNPs), mainly based on polylactic-co-glycolic acid (PLGA), have been already validated and approved for the treatment of cancer, neurologic dysfunctions and hormonal-related diseases. Despite promising no PNPs-based therapy for neurodegenerative disorders is available up to date. To stimulate the research in the area the studies performed so far with polylactic-co-glycolic acid (PLGA) nanoparticles as well as the techniques aimed to improve PNPs BBB permeability and drug targeting were revised. Bearing in mind NDs pharmacological therapy landscape huge efforts must be done in finding new therapeutic solutions along with the translation of the most promising results to the clinic, which hopefully will converge in the development of effective drugs in a foreseeable future.

Liposome based drug delivery as a potential treatment option for Alzheimer's disease

Alzheimer's disease is a neurodegenerative condition leading to atrophy of the brain and robbing nearly 5.8 million individuals in the United States age 65 and older of their cognitive functions. Alzheimer's disease is associated with dementia and a progressive decline in memory, thinking, and social skills, eventually leading to a point that the individual can no longer perform daily activities independently. Currently available drugs on the market temporarily alleviate the symptoms, however, they are not successful in slowing down the progression of Alzheimer's disease. Treatment and cures have been constricted due to the difficulty of drug delivery to the blood-brain barrier. Several studies have led to identification of vesicles to transport the necessary drugs through the blood-brain barrier that would typically not achieve the targeted area through systemic delivered medications. Recently, liposomes have emerged as a viable drug delivery agent to transport drugs that are not able to cross the blood-brain barrier. Liposomes are being used as a component of nanoparticle drug delivery; due to their biocompatible nature; and possessing the capability to carry both lipophilic and hydrophilic therapeutic agents across the blood brain barrier into the brain cells. Studies indicate the importance of liposomal based drug delivery in treatment of neurodegenerative disorders. The idea is to encapsulate the drugs inside the properly engineered liposome to generate a response of treatment. Liposomes are engineered to target specific diseased moieties and also several surface modifications of liposomes are under research to create a clinical path to the management of Alzheimer's disease. This review deals with Alzheimer's disease and emphasize on challenges associated with drug delivery to the brain, and how liposomal drug delivery can play an important role as a drug delivery method for the treatment of Alzheimer's disease. This review also sheds some light on variation of liposomes. Additionally, it emphasizes on the liposomal formulations which are currently researched or used for treatment of Alzheimer's disease and also discusses the future prospect of liposomal based drug delivery in Alzheimer's disease.

Multifunctional icariin and tanshinone IIA co-delivery liposomes with potential application for Alzheimer's disease

The blood-brain barrier (BBB) is a protective barrier for brain safety, but it is also a major obstacle to the delivery of drugs to the cerebral parenchyma such as the hippocampus, hindering the treatment of central nervous system diseases such as Alzheimer's disease (AD). In this work, an anti-AD brain-targeted nanodrug delivery system by co-loading icariin (ICA) and tanshinone IIA (TSIIA) into Aniopep-2-modified long-circulating (Ang2-ICA/TSIIA) liposomes was developed. Low-density lipoprotein receptor-related protein-1 (LRP1) was a receptor overexpressed on the BBB. Angiopep-2, a specific ligand of LRP1, exhibited a high binding efficiency with LRP1. Additionally, ICA and TSIIA, drugs with neuroprotective effects are loaded into the liposomes, so that the liposomes not only have an effective BBB penetration effect, but also have a potential anti-AD effect. The prepared Ang2-ICA/TSIIA liposomes appeared narrow dispersity and good stability with a diameter of 110 nm, and a round morphology. Cell uptake observations, BBB models in vitro, and imaging analysis in vivo showed that Ang2-ICA/TSIIA liposomes not only penetrate the BBB through endocytosis, but also accumulate in N2a cells or brain tissue. The pharmacodynamic analysis in vivo demonstrated that Ang2-ICA/TSIIA liposomes could improve AD-like pathological features in APP/PS1 mice, including inhibiting neuroinflammation and oxidative stress, reducing apoptosis, protecting neurons, and improving cognitive function. Therefore, Ang2-ICA/TSIIA liposomes are considered a potentially effective therapeutic strategy for AD.

Block copolymers in Alzheimer's disease therapy: A perceptive to revolutionize biomaterials

Alzheimer's disease is a fatal illness associated with two persistent problems in treatment i. ineffective drug transportation across the bio-membranes and ii. on-site targeting. Such problems originate from the combinational factors for non-specific targets, physicochemical limitations in the delivery of the active agents and insignificant permeability across blood-brain-barrier. In this context, block copolymers such as PLGA-PEG, PEG-PLA, Poloxamers, PLGA-PEG-PLGA triblock copolymers, etc. present interesting potential in the development of nano-sized carrier systems like polymerosomes, polymeric micelles, etc. for the management and treatment of Alzheimer's disease. Modifications of block copolymers display improvement in solubility and reduction in toxicity due to the process of complexation, functionalization, dose reduction and modification of kinetics for the rate of release. This review article focuses on new insights into different copolymers and their superiority over conventional polymers in Alzheimer's disease for long-term therapy in the body. Association of block copolymers to therapy of Alzheimer's disease overcome the limitations of drug delivery by offering attributes such as smaller molecular size (less than 150 nm), higher solubility owing to hydrophilic interactions between polymeric components and systemic environment, better entrapment efficiency (above 80%) due to large effective surface area and long-term stability for sensitive actives such as peptides, monoclonal antibodies, curcumin, resveratrol, catechins, etc. With such multifunctional features, block copolymers actively permeate the bio-membrane as polymeric nanoparticles, nanomicelles and polymerosomes using different mechanisms such as transcellular- and receptor-mediated transportation to reach target neural network as well as extra-neuronal amyloid-β plaques for anti-Alzheimer's disease activity with neuroprotective action. These polymers emerge as important components for personalized therapy with potential applications in biosensing, drug delivery, theranostics, etc. for qualitative and quantitative predictions in the detection and treatment of Alzheimer's disease.

Nanotechnology-Based Drug Delivery Strategies to Repair the Mitochondrial Function in Neuroinflammatory and Neurodegenerative Diseases

Mitochondria are vital organelles in eukaryotic cells that control diverse physiological processes related to energy production, calcium homeostasis, the generation of reactive oxygen species, and cell death. Several studies have demonstrated that structural and functional mitochondrial disturbances are involved in the development of different neuroinflammatory (NI) and neurodegenerative (ND) diseases (NI&NDDs) such as multiple sclerosis, Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. Remarkably, counteracting mitochondrial impairment by genetic or pharmacologic treatment ameliorates neurodegeneration and clinical disability in animal models of these diseases. Therefore, the development of nanosystems enabling the sustained and selective delivery of mitochondria-targeted drugs is a novel and effective strategy to tackle NI&NDDs. In this review, we outline the impact of mitochondrial dysfunction associated with unbalanced mitochondrial dynamics, altered mitophagy, oxidative stress, energy deficit, and proteinopathies in NI&NDDs. In addition, we review different strategies for selective mitochondria-specific ligand targeting and discuss novel nanomaterials, nanozymes, and drug-loaded nanosystems developed to repair mitochondrial function and their therapeutic benefits protecting against oxidative stress, restoring cell energy production, preventing cell death, inhibiting protein aggregates, and improving motor and cognitive disability in cellular and animal models of different NI&NDDs.

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.

PLGA Nanoparticle-Based Formulations to Cross the Blood-Brain Barrier for Drug Delivery: From R&D to cGMP

The blood–brain barrier (BBB) is a natural obstacle for drug delivery into the human brain, hindering treatment of central nervous system (CNS) disorders such as acute ischemic stroke, brain tumors, and human immunodeficiency virus (HIV)-1-associated neurocognitive disorders. Poly(lactic-co-glycolic acid) (PLGA) is a biocompatible polymer that is used in Food and Drug Administration (FDA)-approved pharmaceutical products and medical devices. PLGA nanoparticles (NPs) have been reported to improve drug penetration across the BBB both in vitro and in vivo. Poly(ethylene glycol) (PEG), poly(vinyl alcohol) (PVA), and poloxamer (Pluronic) are widely used as excipients to further improve the stability and effectiveness of PLGA formulations. Peptides and other linkers can be attached on the surface of PLGA to provide targeting delivery. With the newly published guidance from the FDA and the progress of current Good Manufacturing Practice (cGMP) technologies, manufacturing PLGA NP-based drug products can be achieved with higher efficiency, larger quantity, and better quality. The translation from bench to bed is feasible with proper research, concurrent development, quality control, and regulatory assurance.

Lactoferrin, a multi-functional glycoprotein: Active therapeutic, drug nanocarrier & targeting ligand

Recent progress in protein-based nanomedicine, inspired by the success of Abraxane® albumin-paclitaxel nanoparticles, have resulted in novel therapeutics used for treatment of challenging diseases like cancer and viral infections. However, absence of specific drug targeting, poor pharmacokinetics, premature drug release, and off-target toxicity are still formidable challenges in the clinic. Therefore, alternative protein-based nanomedicines were developed to overcome those challenges. In this regard, lactoferrin (Lf), a glycoprotein of transferrin family, offers a promising biodegradable well tolerated material that could be exploited both as an active therapeutic and drug nanocarrier. This review highlights the major pharmacological actions of Lf including anti-cancer, antiviral, and immunomodulatory actions. Delivery technologies of Lf to improve its pries and enhance its efficacy were also reviewed. Moreover, different nano-engineering strategies used for fabrication of drug-loaded Lf nanocarriers were discussed. In addition, the use of Lf for functionalization of drug nanocarriers with emphasis on tumor-targeted drug delivery was illustrated. Besides its wide application in oncology nano-therapeutics, we discussed the recent advances of Lf-based nanocarriers as efficient platforms for delivery of anti-parkinsonian, anti-Alzheimer, anti-viral drugs, immunomodulatory and bone engineering applications.

Indocyanine Green J Aggregates in Polymersomes for Near-Infrared Photoacoustic Imaging

Clinical translation of photoacoustic imaging (PAI) has been limited by the lack of near-infrared (NIR) contrast agents with low toxicity required for regulatory approval. Herein, J aggregates of indocyanine green (ICG) with strong NIR absorbance were encapsulated at high loadings within small 77 nm polymersomes (nanocapsules) composed of poly(lactide-co-glycolide-b-poly(ethylene glycol)) (PLGA-b-PEG) bilayers, thus enabling PAI of of breast and ovarian cancer cells with high specificity and a sensitivity at the level of ∼100 total cells. All of the major components of the polymersomes are FDA approved and used in the clinic. During formation of polymersomes with a water-in-oil-in-water double emulsion process, loss of ICG from the ICG J aggregates was minimized by coating them with a layer of branched polyethylenimine and by providing excess "sacrificial" ICG to adsorb at the oil-water interfaces. The encapsulated J aggregates were protected against dissociation by the polymersome shell for 24 h in 100% fetal bovine serum, after which the polymersomes biodegraded and the J aggregates dissociated to ICG monomers.

Nanomaterial-based blood-brain-barrier (BBB) crossing strategies

Increasing attention has been paid to the diseases of central nervous system (CNS). The penetration efficiency of most CNS drugs into the brain parenchyma is rather limited due to the existence of blood-brain barrier (BBB). Thus, BBB crossing for drug delivery to CNS remains a significant challenge in the development of neurological therapeutics. Because of the advantageous properties (e.g., relatively high drug loading content, controllable drug release, excellent passive and active targeting, good stability, biodegradability, biocompatibility, and low toxicity), nanomaterials with BBB-crossability have been widely developed for the treatment of CNS diseases. This review summarizes the current understanding of the physiological structure of BBB, and provides various nanomaterial-based BBB-crossing strategies for brain delivery of theranostic agents, including intranasal delivery, temporary disruption of BBB, local delivery, cell penetrating peptide (CPP) mediated BBB-crossing, receptor mediated BBB-crossing, shuttle peptide mediated BBB-crossing, and cells mediated BBB-crossing. Clinicians, biologists, material scientists and chemists are expected to be interested in this review.

Protein-functionalized nanoparticles derived from end-functional polymers and polymer prodrugs for crossing the blood-brain barrier

Nanoparticles may provide a viable way for neuroprotective drugs to cross the blood-brain barrier (BBB), which limits the passage of most drugs from the peripheral circulation to the brain. Heterotelechelic polymer prodrugs comprising a neuroprotective model drug (adenosine) and a maleimide functionality were synthesized by the "drug-initiated" approach and subsequent nitroxide exchange reaction. Nanoparticles were obtained by nanoprecipitation and exhibited high colloidal stability with diameters in the 162-185 nm range and narrow size distributions. Nanoparticles were then covalently surface-conjugated to different proteins (albumin, α2-macroglobulin and fetuin A) to test their capability of enhancing BBB translocation. Their performances in terms of endothelial permeability and cellular uptake in an in vitro BBB model were compared to that of similar nanoparticles with surface-adsorbed proteins, functionalized or not with the drug. It was shown that bare NPs (i.e., NPs not surface-functionalized with proteins) without the drug exhibited significant permeability and cellular uptake, which were further enhanced by NP surface functionalization with α2-macroglobulin. However, the presence of the drug at the polymer chain-end prevented efficient passage of all types of NPs through the BBB model, likely due to adecrease in the hydrophobicity of the nanoparticle surface and alteration of the protein binding/coupling, respectively. These results established a new and facile synthetic approach for the surface-functionalization of polymer nanoparticles for brain delivery purposes.

Enhanced uptake in 2D- and 3D- lung cancer cell models of redox responsive PEGylated nanoparticles with sensitivity to reducing extra- and intracellular environments

In the treatment of lung cancer, there is an urgent need of innovative medicines to optimize pharmacological responses of conventional chemotherapeutics while attenuating side effects. Here, we have exploited some relatively unexplored subtle differences in reduction potential, associated with cancer cell microenvironments in addition to the well-known changes in intracellular redox environment. We report the synthesis and application of novel redox-responsive PLGA (poly(lactic-co-glycolic acid)) -PEG (polyethylene glycol) nanoparticles (RR-NPs) programmed to change surface properties when entering tumor microenvironments, thus enhancing cell internalization of the particles and their drug cargo. The new co-polymers, in which PEG and PLGA were linked by 'anchiomeric effector' dithiylethanoate esters, were synthesized by a combination of ring-opening polymerization and Michael addition reactions and employed to prepare NPs. Non redox-responsive nanoparticles (nRR-NPs) based on related PLGA-PEG copolymers were also prepared as comparators. Spherical NPs of around 120 nm diameter with a low polydispersity index and negative zeta potential as well as good drug loading of docetaxel were obtained. The NPs showed prolonged stability in relevant simulated biological fluids and a high ability to penetrate an artificial mucus layer due to the presence of the external PEG coating. Stability, FRET and drug release studies in conditions simulating intracellular reductive environments demonstrated a fast disassembly of the external shell of the NPs, thus triggering on-demand drug release. FACS measurements and confocal microscopy showed increased and faster uptake of RR-NPs in both 2D- and 3D- cell culture models of lung cancer compared to nRR-NPs. In particular, the 'designed-in' reductive instability of RR-NPs in conditioned cell media, the fast PEG release in the extracellular compartment, as well as a diminution of uptake rate in control experiments where extracellular thiols were neutralized, suggested a partial extracellular release of the PEG fringe that promoted rapid internalization of the residual NPs into cells. Taken together, these results provide further evidence of the effectiveness of PEGylated reducible nanocarriers to permeate mucus layer barriers, and establish a new means to enhance cancer cell uptake of drug carriers by extra-and intra-cellular cleavage of protein- and cell-shielding hydrophilic blocks.

Lactoferrin functionalized PEG-PLGA nanoparticles of shikonin for brain targeting therapy of glioma

Shikonin (SHK) is a highly liposoluble naphthoquinone pigment has recently been investigated as a potential antiglioma agent. However, shikonin shows several limitations like poor aqueous solubility, short half-life and non-selective biodistribution. Herein, we have developed a nanoparticles (NPs) prepared from PEG-PLGA using an emulsion solvent evaporation method. Nanoparticle surfaces were modified by coating with lactoferrin (Lf) to improve the crossing of the blood brain barrier and targeting of glioma cells via receptor-mediated path-ways. X-ray powder diffraction and differential scanning calorimetry analysis revealed the amorphous nature of SHK encapsulated within the NPs. Moreover, the drug-loaded NPs exhibit narrow size distribution and high encapsulation efficiency. The in vitro release experiments of the NPs exhibited sustained release for more than 72h. When compared to free SHK and SHK/NPs, in vivo study demonstrated higher brain concentration of SHK, indicating a significant effect of Lf coated NPs on brain targeting. Accordingly, these findings provide evidence for the potential of Lf-modified NPs as a targeted delivery system for brain glioblastomas treatment.

Angiopep-2-conjugated poly(ethylene glycol)-co- poly(ε-caprolactone) polymersomes for dual-targeting drug delivery to glioma in rats

The blood–brain barrier is a formidable obstacle for glioma chemotherapy due to its compact structure and drug efflux ability. In this study, a dual-targeting drug delivery system involving Angiopep-2-conjugated biodegradable polymersomes loaded with doxorubicin (Ang-PS-DOX) was developed to exploit transport by the low-density lipoprotein receptor-related protein 1 (LRP1), which is overexpressed in both blood–brain barrier and glioma cells. The polymersomes (PS) were prepared using a thin-film hydration method. The PS were loaded with doxorubicin using the pH gradient method (Ang-PS-DOX). The resulting PS were uniformly spherical, with diameters of ~135 nm and with ~159.9 Angiopep-2 molecules on the surface of each PS. The drug-loading capacity and the encapsulation efficiency for doxorubicin were 7.94%±0.17% and 95.0%±1.6%, respectively. Permeability tests demonstrated that the proton diffusion coefficient across the PS membrane was far slower than that across the liposome membrane, and the common logarithm value was linearly dependent on the dioxane content in the external phase. Compared with PS-DOX, Ang-PS-DOX demonstrated significantly higher cellular uptake and stronger cytotoxicity in C6 cells. In vivo pharmacokinetics and brain distribution experiments revealed that Ang-PS-DOX achieved a more extensive distribution and more abundant accumulation in glioma cells than PS-DOX. Moreover, the survival time of glioma-bearing rats treated with Ang-PS-DOX was significantly prolonged compared with those treated with PS-DOX or a solution of free doxorubicin. These results suggested that Ang-PS-DOX can target glioma cells and enhance chemotherapeutic efficacy.

Research and development on lactoferrin and its derivatives in China from 2011–2015

Lactoferrin (Lf), a multifunctional glycoprotein, is an important antimicrobial and immune regulatory protein present in neutrophils and most exocrine secretions of mammals. Lactoferricin (Lfcin) is located in the N-terminal region of this protein. In this review, the current state of research into Lf and Lfcin in China is described. Searching with HistCite software in Web Sci located 118 papers published by Chinese researchers from 2011–2015, making China one of the top 3 producers of Lf research and development in the world. The biological functions of Lf and Lfcin are discussed, including antibacterial, antiviral, antifungal, anticarcinogenic, and anti-inflammatory activities; targeted drug delivery, induction of neurocyte, osteoblast, and tenocyte growth, and possible mechanisms of action. The preparation and heterologous expression of Lf in animals, bacteria, and yeast are discussed in detail. Five Lf-related food additive factories and 9 Lf-related health food production companies are certified by the China Food and Drug Administration (CFDA). The latest progress in the generation of transgenic livestock in China, the safety of the use of transgenic animals, and future prospects for the uses of Lf and Lfcin are also covered.

A dual brain-targeting curcumin-loaded polymersomes ameliorated cognitive dysfunction in intrahippocampal amyloid-β1-42-injected mice

Due to the impermeability of the blood–brain barrier and the nonselective distribution of drugs in the brain, the therapeutic access to intractable neurological disorders is challenging. In this study, dual brain-targeting polymersomes (POs) functionalized by transferrin and Tet-1 peptide (Tf/Tet-1-POs) promoted the transportation of curcumin into the brain and provided neuroprotection. The modification of the ligands that bind to the surface of POs was revealed by X-ray photoelectron spectroscopy analysis. The cell uptake of a coculture model of mouse brain capillary endothelial cells with neurons showed that the Tf/Tet-1-POs had significant transportation properties and possessed affinity for neurons. The pharmacokinetic analysis showed that the blood–brain barrier permeability–surface efficiency of the Tf/Tet-1-POs was 0.28 mL/h/g and that the brain tissue uptake rate (% ID/g) was 0.08, which were significant compared with the controls (P<0.05). The curcumin-encapsulated Tf/Tet-1-POs provided neuroprotection and ameliorated cognitive dysfunction in intrahippocampal amyloid-β_1–42-injected mice. These results suggest that the dual brain-targeting POs are more capable of drug delivery to the brain that can be exploited as a multiple noninvasive vehicle for targeting therapeutics.

Nano carriers for drug transport across the blood-brain barrier

Effective therapy lies in achieving a therapeutic amount of drug to the proper site in the body and then maintaining the desired drug concentration for a sufficient time interval to be clinically effective for treatment. The blood-brain barrier (BBB) hinders most drugs from entering the central nervous system (CNS) from the blood stream, leading to the difficulty of delivering drugs to the brain via the circulatory system for the treatment, diagnosis and prevention of brain diseases. Several brain drug delivery approaches have been developed, such as intracerebral and intracerebroventricular administration, intranasal delivery and blood-to-brain delivery, as a result of transient BBB disruption induced by biological, chemical or physical stimuli such as zonula occludens toxin, mannitol, magnetic heating and ultrasound, but these approaches showed disadvantages of being dangerous, high cost and unsuitability for most brain diseases and drugs. The strategy of vector-mediated blood-to-brain delivery, which involves improving BBB permeability of the drug-carrier conjugate, can minimize side effects, such as being submicrometre objects that behave as a whole unit in terms of their transport and properties, nanomaterials, are promising carrier vehicles for direct drug transport across the intact BBB as a result of their potential to enter the brain capillary endothelial cells by means of normal endocytosis and transcytosis due to their small size, as well as their possibility of being functionalized with multiple copies of the drug molecule of interest. This review provids a concise discussion of nano carriers for drug transport across the intact BBB, various forms of nanomaterials including inorganic/solid lipid/polymeric nanoparticles, nanoemulsions, quantum dots, nanogels, liposomes, micelles, dendrimers, polymersomes and exosomes are critically evaluated, their mechanisms for drug transport across the BBB are reviewed, and the future directions of this area are fully discussed.

Translocation of LRP1 targeted carbon nanotubes of different diameters across the blood-brain barrier in vitro and in vivo

Brain glioblastoma and neurodegenerative diseases are still largely untreated due to the inability of most drugs to cross the blood-brain barrier (BBB). Nanoparticles have emerged as promising tools for drug delivery applications to the brain; in particular carbon nanotubes (CNTs) that have shown an intrinsic ability to cross the BBB in vitro and in vivo. Angiopep-2 (ANG), a ligand for the low-density lipoprotein receptor-related protein-1 (LRP1), has also shown promising results as a targeting ligand for brain delivery using nanoparticles (NPs). Here, we investigate the ability of ANG-targeted chemically-functionalised multi-walled carbon nanotubes (f-MWNTs) to cross the BBB in vitro and in vivo. ANG was conjugated to wide and thin f-MWNTs creating w-MWNT-ANG and t-MWNT-ANG, respectively. All f-MWNTs were radiolabelled to facilitate quantitative analyses by γ-scintigraphy. ANG conjugation to f-MWNTs enhanced BBB transport of w- and t-MWNTs-ANG compared to their non-targeted equivalents using an in vitro co-cultured BBB model consisting of primary porcine brain endothelial cells (PBEC) and primary rat astrocytes. Additionally, following intravenous administration w-MWNTs-ANG showed significantly higher whole brain uptake than the non-targeted w-MWNT in vivo reaching ~2% injected dose per g of brain (%ID/g) within the first hour post-injection. Furthermore, using a syngeneic glioma model, w-MWNT-ANG showed enhanced uptake in glioma brain compared to normal brain at 24h post-injection. t-MWNTs-ANG, on the other hand, showed higher brain accumulation than w-MWNTs. However, no significant differences were observed between t-MWNT and t-MWNT-ANG indicating the importance of f-MWNTs diameter towards their brain accumulation. The inherent brain accumulation ability of f-MWNTs coupled with improved brain-targeting by ANG favours the future clinical applications of f-MWNT-ANG to deliver active therapeutics for brain glioma therapy.

Strategies of polymeric nanoparticles for enhanced internalization in cancer therapy

In order to achieve long circulation time and high drug accumulation in the tumor sites via the EPR effects, anticancer drugs have to be protected by non-fouling polymers such as poly(ethylene glycol) (PEG), poly(ethylene oxide) (PEO), dextran, and poly(acrylic acid) (PAA). However, the dense layer of stealth polymer also prohibits efficient uptake of anticancer drugs by target cancer cells. For cancer therapy, it is often more desirable to accomplish rapid cellular uptake after anticancer drugs arriving at the pathological site, which could on one hand maximize the therapeutic efficacy and on the other hand reduce probability of drug resistance in cells. In this review, special attention will be focused on the recent potential strategies that can enable drug-loaded polymeric nanoparticles to rapidly recognize cancer cells, leading to enhanced internalization.

Extracellular vesicles and their synthetic analogues in aging and age-associated brain diseases

Multicellular organisms rely upon diverse and complex intercellular communications networks for a myriad of physiological processes. Disruption of these processes is implicated in the onset and propagation of disease and disorder, including the mechanisms of senescence at both cellular and organismal levels. In recent years, secreted extracellular vesicles (EVs) have been identified as a particularly novel vector by which cell-to-cell communications are enacted. EVs actively and specifically traffic bioactive proteins, nucleic acids, and metabolites between cells at local and systemic levels, modulating cellular responses in a bidirectional manner under both homeostatic and pathological conditions. EVs are being implicated not only in the generic aging process, but also as vehicles of pathology in a number of age-related diseases, including cancer and neurodegenerative and disease. Thus, circulating EVs-or specific EV cargoes-are being utilised as putative biomarkers of disease. On the other hand, EVs, as targeted intercellular shuttles of multipotent bioactive payloads, have demonstrated promising therapeutic properties, which can potentially be modulated and enhanced through cellular engineering. Furthermore, there is considerable interest in employing nanomedicinal approaches to mimic the putative therapeutic properties of EVs by employing synthetic analogues for targeted drug delivery. Herein we describe what is known about the origin and nature of EVs and subsequently review their putative roles in biology and medicine (including the use of synthetic EV analogues), with a particular focus on their role in aging and age-related brain diseases.

Nanomedicine for the treatment of Alzheimer's disease

Alzheimer's disease affects more than 35 million people worldwide and this number is presumed to double by the year 2050. Currently, there is no efficient therapy for this disorder but a promising approach is represented by nanotechnology, easily multifunctionalizable devices with size in the order of billionth of meter. This review provides a concise survey on the nano-based strategies for Alzheimer's disease treatment, aiming at carrying drugs across the blood–brain barrier, in particular to target the metabolism of β-amyloid peptide, a pivotal player in this pathology.

The effect of sex on humanin levels in healthy adults and patients with uncomplicated type 1 diabetes mellitus

Diabetes mellitus (DM) is associated with a loss of renal and vascular protection in women compared with men, but the responsible mechanisms are unclear. Recent experimental work implicated humanin (HN) as a novel cytoprotective hormone in DM. Our goal was to measure sex-related differences in HN levels in uncomplicated type 1 DM patients (T1D) and healthy controls (HC), as well as the interaction between HN, circulating neurohormones, and vascular function. Plasma HN, cGMP and aldosterone, blood pressure (BP), glomerular filtration rate, and effective renal plasma flow (inulin and para-aminohippurate) were measured in HC (11 men, 10 women) and T1D (23 men and 18 women) during clamped euglycemia (4-6 mmol·L(-1)). Plasma HN levels were generally lower in HC men by comparison with the women, but the differences were not statistically significant. In contrast, levels in the T1D men were higher compared with the T1D women (p = 0.026) and HC men (p < 0.0001). In the HC men, but not the women, HN correlated negatively with BP, but not with renal function, cGMP, or aldosterone. In the T1D men, HN negatively correlated with plasma cGMP. In the T1D women, HN did not correlate with neurohormones or vascular function. Future work should determine the role of HN in the pathogenesis of sex-related vascular function differences in DM.

Novel formulations for antimicrobial peptides

Peptides in general hold much promise as a major ingredient in novel supramolecular assemblies. They may become essential in vaccine design, antimicrobial chemotherapy, cancer immunotherapy, food preservation, organs transplants, design of novel materials for dentistry, formulations against diabetes and other important strategical applications. This review discusses how novel formulations may improve the therapeutic index of antimicrobial peptides by protecting their activity and improving their bioavailability. The diversity of novel formulations using lipids, liposomes, nanoparticles, polymers, micelles, etc., within the limits of nanotechnology may also provide novel applications going beyond antimicrobial chemotherapy.

Agile delivery of protein therapeutics to CNS

A variety of therapeutic proteins have shown potential to treat central nervous system (CNS) disorders. Challenge to deliver these protein molecules to the brain is well known. Proteins administered through parenteral routes are often excluded from the brain because of their poor bioavailability and the existence of the blood-brain barrier (BBB). Barriers also exist to proteins administered through non-parenteral routes that bypass the BBB. Several strategies have shown promise in delivering proteins to the brain. This review, first, describes the physiology and pathology of the BBB that underscore the rationale and needs of each strategy to be applied. Second, major classes of protein therapeutics along with some key factors that affect their delivery outcomes are presented. Third, different routes of protein administration (parenteral, central intracerebroventricular and intraparenchymal, intranasal and intrathecal) are discussed along with key barriers to CNS delivery associated with each route. Finally, current delivery strategies involving chemical modification of proteins and use of particle-based carriers are overviewed using examples from literature and our own work. Whereas most of these studies are in the early stage, some provide proof of mechanism of increased protein delivery to the brain in relevant models of CNS diseases, while in few cases proof of concept had been attained in clinical studies. This review will be useful to broad audience of students, academicians and industry professionals who consider critical issues of protein delivery to the brain and aim developing and studying effective brain delivery systems for protein therapeutics.

The proton permeability of self-assembled polymersomes and their neuroprotection by enhancing a neuroprotective peptide across the blood-brain barrier after modification with lactoferrin

Biotherapeutics such as peptides possess strong potential for the treatment of intractable neurological disorders. However, because of their low stability and the impermeability of the blood-brain barrier (BBB), biotherapeutics are difficult to transport into brain parenchyma via intravenous injection. Herein, we present a novel poly(ethylene glycol)-poly(d,l-lactic-co-glycolic acid) polymersome-based nanomedicine with self-assembled bilayers, which was functionalized with lactoferrin (Lf-POS) to facilitate the transport of a neuroprotective peptide into the brain. The apparent diffusion coefficient (D*) of H(+) through the polymersome membrane was 5.659 × 10(-26) cm(2) s(-1), while that of liposomes was 1.017 × 10(-24) cm(2) s(-1). The stability of the polymersome membrane was much higher than that of liposomes. The uptake of polymersomes by mouse brain capillary endothelial cells proved that the optimal density of lactoferrin was 101 molecules per polymersome. Fluorescence imaging indicated that Lf101-POS was effectively transferred into the brain. In pharmacokinetics, compared with transferrin-modified polymersomes and cationic bovine serum albumin-modified polymersomes, Lf-POS obtained the greatest BBB permeability surface area and percentage of injected dose per gram (%ID per g). Furthermore, Lf-POS holding S14G-humanin protected against learning and memory impairment induced by amyloid-β25-35 in rats. Western blotting revealed that the nanomedicine provided neuroprotection against over-expression of apoptotic proteins exhibiting neurofibrillary tangle pathology in neurons. The results indicated that polymersomes can be exploited as a promising non-invasive nanomedicine capable of mediating peptide therapeutic delivery and controlling the release of drugs to the central nervous system.

Targeted delivery of the RGD-labeled biodegradable polymersomes loaded with the hydrophilic drug oxymatrine on cultured hepatic stellate cells and liver fibrosis in rats

Oxymatrine (OM) is an alkaloid extracted from a Chinese herb that has been found to possess an anti-hepatic fibrosis effect, although its anti-fibrotic potential is limited due to a lack of targeting specificity, a short half-life and adverse effects. Polymersomes (PM) assembled from amphiphilic block copolymers represent promising vesicles for applications that include drug delivery and surface functionalization. The aim of this study was to develop a novel drug carrier based on PM modified with the peptide RGD and evaluate its therapeutic effect on liver fibrosis. A series of PM based on poly(ethylene glycol)-b-poly(ε-caprolactone) (PEG-b-PCL) were prepared and characterized. OM was loaded into PM by a pH-gradient method then the OM-loaded PM was modified with RGD peptide to obtain RGD-PM-OM. The average drug loading of RGD-PM-OM, with a size of 95 nm, was 6.8%. The targeting effects of the system were determined in cultured hepatic stellate cells (HSCs) and bile duct-ligated rats (BLD). RGD-PM-OM displayed better suppression of HSCs proliferation and significantly reduced the expression of the genes for α-SMA and collagen lα1 in cultured HSCs. Furthermore, RGD-PM-OM exhibited markedly superior anti-fibrosis activity by reducing the levels of PC-III and IV-C in serum and connective tissue deposition in BLD compared with PM-OM and OM. These results indicate that targeted RGD-PM-OM markedly attenuates the effects of hepatic fibrosis.

Lactoferrin inhibits dexamethasone-induced chondrocyte impairment from osteoarthritic cartilage through up-regulation of extracellular signal-regulated kinase 1/2 and suppression of FASL, FAS, and Caspase 3

Dexamethasone (Dex) is commonly used for osteoarthritis (OA) with excellent anti-inflammatory and analgesic effect. However, Dex also has many side effects following repeated use over prolonged periods mainly through increasing apoptosis and inhibiting proliferation. Lactoferrin (LF) exerts significantly anabolic effect on many cells and little is known about its effect on OA chondrocytes. Therefore, the aim of this study is to investigate whether LF can inhibit Dex-induced OA chondrocytes apoptosis and explore its possible molecular mechanism involved in. MTT assay was used to determine the optimal concentration of Dex and recombinant human LF (rhLF) on chondrocytes at different time and dose points. Chondrocytes were then stimulated with Dex in the absence or presence of optimal concentration of rhLF. Cell proliferation and viability were evaluated using MTT and LIVE/DEAD assay, respectively. Cell apoptosis was evaluated by multi-parameter apoptosis assay kit using both confocal microscopy and flow cytometry, respectively. The expression of extracellular signal-regulated kinase (ERK), FAS, FASL, and Caspase-3 (CASP3) at the mRNA and protein levels were examined by real-time polymerase chain reaction (PCR) and immunocytochemistry, respectively. The optimal concentration of Dex (25 μg/ml) and rhLF (200 μg/ml) were chosen for the following experiments. rhLF significantly reversed the detrimental effect of Dex on chondrocytes proliferation, viability, and apoptosis. In addition, rhLF significantly prevented Dex-induced down-regulation of ERK and up-regulation of FAS, FASL, and CASP3. These findings demonstrated that rhLF acts as an anabolic effect on chondrocytes through significantly reversing Dex-induced chondrocytes apoptosis. This study may contribute to further investigating the clinical application of LF on OA.

Novel insights into appropriate encapsulation methods for bioactive compounds into polymers: a study with peptides and HDAC inhibitors

The use of different nanoparticles (NPs) for successful encapsulation of bioactive substances is discussed. The inclusion efficiency into liposomes, acetalated dextran (Ac-Dex), and variants of poly[(lactic acid)-co-(glycolic acid)] (PLGA) NPs is analyzed after chemical degradation. Efficient inclusion of SIRT1 inhibitor Ex527 in liposomes, Ac-Dex- and PLGA-NPs is observed for all procedures used. Activity of Ex527 is demonstrated by monitoring the acetylation status of SIRT1-target p53. In contrast, small peptides are only incorporated into acid-terminated PLGA-NPs and marginally into Ac-Dex-NPs. The yield depends on peptide sequence and terminal modifications. Activity is exemplified for angiotensin II using the dynamic mass redistribution technology.