In Vitro Biocompatibility and Endothelial Permeability of Branched Polyglycidols Generated by Ring-Opening Polymerization of Glycidol with B(C6F5)3 under Dry and Wet Conditions.

Polyglycidol or polyglycerol (PG), a polyether widely used in biomedical applications, has not been extensively studied in its branched cyclic form (bcPG), despite extensive research on hyperbranched PG (HPG). This study explores the biomedical promise of bcPG, particularly its ability to cross the blood-brain barrier (BBB). We evaluate in vitro biocompatibility, endothelial permeability, and formation of branched linear PG (blPG) as topological impurities in the presence of water. Small angle X-ray scattering in solution revealed a fractal dimension of approximately two for bcPG and the mixture bc+blPG, suggesting random branching. Comparisons of cytotoxicity and endothelial permeability between bcPG, bc+blPG, and HPG in a BBB model using hCMEC/D3 cells showed different biocompatibility profiles and higher endothelial permeability for HPG. bcPG showed a tendency to accumulate around cell nuclei, in contrast to the behavior of HPG. This study contributes to the understanding of the influence of polymer topology on biological behavior.

Givinostat-Liposomes: Anti-Tumor Effect on 2D and 3D Glioblastoma Models and Pharmacokinetics.

Glioblastoma is the most common and aggressive brain tumor, associated with poor prognosis and survival, representing a challenging medical issue for neurooncologists. Dysregulation of histone-modifying enzymes (HDACs) is commonly identified in many tumors and has been linked to cancer proliferation, changes in metabolism, and drug resistance. These findings led to the development of HDAC inhibitors, which are limited by their narrow therapeutic index. In this work, we provide the proof of concept for a delivery system that can improve the in vivo half-life and increase the brain delivery of Givinostat, a pan-HDAC inhibitor. Here, 150-nm-sized liposomes composed of cholesterol and sphingomyelin with or without surface decoration with mApoE peptide, inhibited human glioblastoma cell growth in 2D and 3D models by inducing a time- and dose-dependent reduction in cell viability, reduction in the receptors involved in cholesterol metabolism (from -25% to -75% of protein levels), and reduction in HDAC activity (-25% within 30 min). In addition, liposome-Givinostat formulations showed a 2.5-fold increase in the drug half-life in the bloodstream and a 6-fold increase in the amount of drug entering the brain in healthy mice, without any signs of overt toxicity. These features make liposomes loaded with Givinostat valuable as potential candidates for glioblastoma therapy.

The 3.0 Cell Communication: New Insights in the Usefulness of Tunneling Nanotubes for Glioblastoma Treatment.

Glioblastoma (GBM) is a particularly challenging brain tumor characterized by a heterogeneous, complex, and multicellular microenvironment, which represents a strategic network for treatment escape. Furthermore, the presence of GBM stem cells (GSCs) seems to contribute to GBM recurrence after surgery, and chemo- and/or radiotherapy. In this context, intercellular communication modalities play key roles in driving GBM therapy resistance. The presence of tunneling nanotubes (TNTs), long membranous open-ended channels connecting distant cells, has been observed in several types of cancer, where they emerge to steer a more malignant phenotype. Here, we discuss the current knowledge about the formation of TNTs between different cellular types in the GBM microenvironment and their potential role in tumor progression and recurrence. Particularly, we highlight two prospective strategies targeting TNTs as possible therapeutics: (i) the inhibition of TNT formation and (ii) a boost in drug delivery between cells through these channels. The latter may require future studies to design drug delivery systems that are exchangeable through TNTs, thus allowing for access to distant tumor niches that are involved in tumor immune escape, maintenance of GSC plasticity, and increases in metastatic potential.

Reduced Levels of ABCA1 Transporter Are Responsible for the Cholesterol Efflux Impairment in ß-Amyloid-Induced Reactive Astrocytes: Potential Rescue from Biomimetic HDLs.

The cerebral synthesis of cholesterol is mainly handled by astrocytes, which are also responsible for apoproteins' synthesis and lipoproteins' assembly required for the cholesterol transport in the brain parenchyma. In Alzheimer disease (AD), these processes are impaired, likely because of the astrogliosis, a process characterized by morphological and functional changes in astrocytes. Several ATP-binding cassette transporters expressed by brain cells are involved in the formation of nascent discoidal lipoproteins, but the effect of beta-amyloid (Aß) assemblies on this process is not fully understood. In this study, we investigated how of Aß1-42-induced astrogliosis affects the metabolism of cholesterol in vitro. We detected an impairment in the cholesterol efflux of reactive astrocytes attributable to reduced levels of ABCA1 transporters that could explain the decreased lipoproteins' levels detected in AD patients. To approach this issue, we designed biomimetic HDLs and evaluated their performance as cholesterol acceptors. The results demonstrated the ability of apoA-I nanodiscs to cross the blood-brain barrier in vitro and to promote the cholesterol efflux from astrocytes, making them suitable as a potential supportive treatment for AD to compensate the depletion of cerebral HDLs.

Therapeutic applications and delivery systems for triptolide.

Triptolide (TPL) is a natural compound and active component of Tripterygium wilfordii Hook F., an Asian native woody vine widely used for over 200 years in Chinese medicine. Hot water, ethanol-ethyl acetate, and chloroform-methanol extracts are the first reported TPL preparations in the literature, and since then, several studies for application in inflammation processes and cancer are described due to the antitumor, anti-inflammatory, and immunosuppressive characteristics of the molecule. However, physicochemical properties such as poor solubility and bioavailability are the main concerns regarding the TPL safety and efficacy in clinical studies since trials have reported adverse side effects alongside the excellent TPL therapeutic effects. Here, we review the main TPL applications and issues related to the drug usage, and a comprehensive summary of diseases is provided. Special emphasis is given to drug delivery systems designed to overcome the TPL physicochemical characteristics such as poor drug solubility, and how to increase efficacy and obtain a safe drug profile. Graphical abstract.

Nanotechnology approaches in the current therapy of skin cancer.

Skin cancer is a high burden disease with a high impact on global health. Conventional therapies have several drawbacks; thus, the development of effective therapies is required. In this context, nanotechnology approaches are an attractive strategy for cancer therapy because they enable the efficient delivery of drugs and other bioactive molecules to target tissues with low toxic effects. In this review, nanotechnological tools for skin cancer will be summarized and discussed. First, pathology and conventional therapies will be presented, followed by the challenges of skin cancer therapy. Then, the main features of developing efficient nanosystems will be discussed, and next, the most commonly used nanoparticles (NPs) described in the literature for skin cancer therapy will be presented. Subsequently, the use of NPs to deliver chemotherapeutics, immune and vaccine molecules and nucleic acids will be reviewed and discussed as will the combination of physical methods and NPs. Finally, multifunctional delivery systems to codeliver anticancer therapeutic agents containing or not surface functionalization will be summarized.

Nanostructured lipid carrier co-delivering tacrolimus and TNF-α siRNA as an innovate approach to psoriasis.

Since psoriasis is an immuno-mediated skin disease, long-term therapies are necessary for its treatment. In clinical investigations, tacrolimus (TAC), a macrolide immunosuppressive inhibitor of calcineurin, arises as an alternative for the treatment of psoriasis, acting in some cytokines involved in the pathogenesis of the disease. Here, we aim to study the psoriasis treatment with TAC and siRNA for one of most cytokines expressed in psoriasis, the TNF-α. A multifunctional nanostructure lipid carrier (NLC) was developed to co-delivery TAC and siRNA. Results showed that the particle size and zeta potential were around 230 nm and + 10 mV, respectively. The release study demonstrated a controlled release of TAC, and the permeation and retention profile in the skin tissue show to be promising for topical application. The cell viability and uptake in murine fibroblast presented low toxicity associated to uptake of NLC in 4 h, and finally, the in vivo animal model demonstrates the efficiency of the NLC multifunctional, exhibiting a reduction of the cytokine TNF-α expression about 7-fold and presenting a synergic effect between the TAC and TNF-α siRNA. The developed system was successfully to treat in vivo psoriatic animal model induced by imiquimod and the synergic combination was reported here for the first time. Graphical abstract.

Influence of Alkyl Chains of Modified Polysuccinimide-Based Polycationic Polymers on Polyplex Formation and Transfection.

The development of polymers with low toxicity and efficient gene delivery remains a significant barrier of nonviral gene therapy. Modification and tuning of chemical structures of carriers is an attractive strategy for efficient nucleic acid delivery. Here, polyplexes consisting of plasmid DNA (pDNA) and dodecylated or non-dodecylated polysuccinimide (PSI)-based polycations are designed, and their transfection ability into HeLa cells is investigated by green fluorescent protein (GFP) expressing cells quantification. All cationic polymers show lower cytotoxicity than those of branched polyethyleneimine (bPEI). PSI and bPEI-based polyplexes have comparable physicochemical properties such as size and charge. Interestingly, a strong interaction between dodecylated polycations and pDNA caused by the hydrophobic moiety is observed in dodecylated PSI derivatives. Moreover, the decrease of GFP expression is associated with lower dissociation of pDNA from polyplexes according to the heparin displacement assay. Besides, a hydrophobization of PSI cationic derivatives with dodecyl side chains can modulate the integrity of polyplexes by hydrophobic interactions, increasing the binding between the polymer and the DNA. These results provide useful information for designing polyplexes with lower toxicity and greater stability and transfection performance.

Current Non-viral siRNA Delivery Systems as a Promising Treatment of Skin Diseases.

BACKGROUND: Gene therapy is a new approach to discover and treat many diseases. It has attracted considerable attention from researchers in the last decades. The gene therapy through RNA interference has been considered one of the most recent and revolutionary approaches used in individualized therapy. In the last years, we have witnessed the rapid development in the field of the gene silencing and knockdown by topical siRNA. Its application in gene therapy has become an attractive alternative for drug development. METHODS: This article will address topical delivery of siRNA as a promising treatment for skin disorders. An update on the advances in siRNA-based nanocarriers as a powerful therapeutic strategy for several skin diseases will be discussed giving emphasis on in vitro evaluations. RESULTS: Through the in-depth review of the literature on the use of siRNAs for skin diseases we realize how widespread this use is. We have also realized that nanoparticles as non-viral vectors are increasingly being explored. Skin diseases where the use of siRNA has been explored most are skin cancer (melanoma and nonmelanoma), psoriasis, vitiligo, dermatitis and leprosy. But we also report here other diseases where the use of siRNA has been growing as acne, alopecia areata, cutaneous leishmaniasis, mycoses, herpes, epidermolysis bullosa and oculocutaneous albinism. Also highlighted, the first clinical trial of siRNA for cutaneous diseases, aimed at Pathyounychia Congenita. CONCLUSION: The treatment of skin diseases based on topical delivery of siRNA, which act by inhibiting the expression of target transcripts, offers many potential therapeutic advantages for suppressing genes into the skin.