Konstantina Papadia

Anti-Aβ-MAb and dually decorated nanoliposomes: effect of Aβ1-42 peptides on interaction with hCMEC/D3 cells.

Anti-Aβ-MAb (Aβ-MAb)-decorated immunoliposomes (LIP) and dually decorated ones (dd-LIP) with OX-26 and Aβ-MAb were constructed. In both cases, the biotin-streptavidin ligation method was applied. All LIP types were characterized for size distribution, zeta potential, and integrity during incubation with serum proteins. Uptake and transcytosis of both LIP types and control vesicles by human brain endothelial hCMEC/D3 cells were measured. All LIP types had mean diameters below 150-200 nm and low polydispersity. Aβ-MAb-LIP uptake was higher than control PEGylated liposomes, while uptake of dd-LIP was similar to that of OX-26-LIP. Aβ-MAb-LIP and dd-LIP uptake increased significantly when cells were pre-incubated with Aβ1-42 peptides; OX-26-LIP uptake was not modulated. Transcytosis of Aβ-MAb-LIP through monolayers was 2.5 times higher when monolayers were pre-incubated with Aβ1-42. Transport of both probes, FITC-dextran and rhodamine-lipid, was equivalent, indicating that Aβ-MAb-LIP are transferred intact through the BBB model. The Aβ peptide-induced increase in binding (and transport) is regulated by the membrane receptors for Aβ1-42 peptides (RAGE), as proven after blocking RAGE by a specific MAb. Aβ1-42 peptides did not modulate the barrier tightness and integrity, as determined by transendothelial resistance and Lucifer Yellow permeability. Additionally, hCMEC/D3 cell viability was not affected by Aβ peptides or by Aβ-MAb-LIP.

Mutant KRAS promotes malignant pleural effusion formation

Malignant pleural effusion (MPE) is the lethal consequence of various human cancers metastatic to the pleural cavity. However, the mechanisms responsible for the development of MPE are still obscure. Here we show that mutant KRAS is important for MPE induction in mice. Pleural disseminated, mutant KRAS bearing tumour cells upregulate and systemically release chemokine ligand 2 (CCL2) into the bloodstream to mobilize myeloid cells from the host bone marrow to the pleural space via the spleen. These cells promote MPE formation, as indicated by splenectomy and splenocyte restoration experiments. In addition, KRAS mutations are frequently detected in human MPE and cell lines isolated thereof, but are often lost during automated analyses, as indicated by manual versus automated examination of Sanger sequencing traces. Finally, the novel KRAS inhibitor deltarasin and a monoclonal antibody directed against CCL2 are equally effective against an experimental mouse model of MPE, a result that holds promise for future efficient therapies against the human condition.

Targeted si-RNA with liposomes and exosomes (extracellular vesicles): How to unlock the potential

The concept of RNA interference therapeutics has been initiated 18 years ago, and the main bottleneck for translation of the technology into therapeutic products remains the delivery of functional RNA molecules into the cell cytoplasm. In the present review article after an introduction about the theoretical basis of RNAi therapy and the main challenges encountered for its realization, an overview of the different types of delivery systems or carriers, used as potential systems to overcome RNAi delivery issues, will be provided. Characteristic examples or results obtained with the most promising systems will be discussed. Focus will be given mostly on the applications of liposomes or other types of lipid carriers, such as exosomes, towards improved delivery of RNAi to therapeutic targets. Finally the approach of integrating the advantages of these two vesicular systems, liposomes and exosomes, as a potential solution to realize RNAi therapy, will be proposed.

Multifunctional LUV liposomes decorated for BBB and amyloid targeting - B. In vivo brain targeting potential in wild-type and APP/PS1 mice

&NA; Multifunctional liposomes (mf‐LIPs) having a curcumin‐lipid ligand (to target amyloids) together with two ligands to target the transferrin, and the low‐density apolipoprotein receptor of the blood‐brain‐barrier (BBB) on their surface, were previously studied (in vitro) as potential theranostic systems for Alzheimers disease (AD) (Papadia et al., 2017, Eur. J. Pharm. Sciences; 101:140–148). Herein, the targeting potential of mf‐LIPs was compared to that of BBB‐LIPs (liposomes having only the two BBB‐specific ligands) in FVB mice (normal), as well as in double transgenic mice (APP/PS1) and their corresponding littermates (WT), by live‐animal (in vivo) and explanted organ (ex vivo) imaging. In FVB mice, the head‐signals of mf‐LIPs and BBB‐LIPs are either similar, or signals from mf‐LIP are higher, suggesting that the co‐presence of the curcumin derivative on the liposome surface does not disturb the functionality of the BBB‐specific ligands. Higher brain / liver + spleen ratios (ex vivo) were calculated post‐injection of mf‐LIP, compared to those found after BBB‐LIP injection, due to the reduced distribution of mf‐LIPs in the liver and spleen; showing that the curcumin ligand increases the stealth properties of liposomes by reducing their uptake by liver and spleen. The later effect is more pronounced when the density of the BBB‐specific ligands on the mf‐LIPs is 0.1 mol%, compared to 0.2%, highlighting the importance of this parameter. When a high lipid dose (4 mg/mouse) is injected in WT and APP/PS1 mice, the head‐signals of mf‐LIPs are significantly higher than those of BBB‐LIPs, but no differences are observed between WT and APP/PS1 mice. However, after administration of a low liposome dose (0.05 mg/mouse) of mf‐LIPs, significant differences in the head‐signals are found between WT and transgenic mice, highlighting the AD theranostic potential of the multifunctional liposomes, as well as the importance of the experimental parameters used in such in vivo screening studies. Graphical abstract Figure. No caption available.

Multifunctional LUV liposomes decorated for BBB and amyloid targeting. A. In vitro proof-of-concept

ABSTRACT Multifunctional LUV liposomes (mf‐LIPs) were developed, having a curcumin‐lipid ligand (TREG) with affinity towards amyloid species, together with ligands to target the transferrin and the LDL receptors of the blood‐brain‐barrier (BBB), on their surface. mf‐LIPs were evaluated for their brain targeting, on hCMEC/D3 monolayers, and for their ability to inhibit A&bgr;‐peptide aggregation. The transport of mf‐LIP across hCMEC/D3 monolayers was similar to that of BBB‐LIPs, indicating that the presence of TREG on their surface does not reduce their brain targeting potential. Likewise, mf‐LIP inhibitory effect on A&bgr; aggregation was similar to that of LIPs functionalized only with TREG, proving that the presence of brain targeting ligands does not reduce the functionality of the amyloid‐specific ligand. Addition of the curcumin‐lipid in some liposome types was found to enhance their integrity and reduce the effect of serum proteins on their interaction with brain endothelial cells. Finally, preliminary in vivo results confirm the in vitro findings. Concluding, the current results reveal the potential of the specific curcumin‐lipid derivative as a component of multifunctional LIPs with efficient brain targeting capability, intended to act as a theragnostic system for AD. Graphical Abstract Figure. No Caption available.

Brain targeting with lipidic nanocarriers

Abstract This chapter deals with lipidic nanocarriers (NCs) that facilitate drug targeting to the brain. Initially, a brief presentation is made of the problems delivering drugs to the brain due to the blood–brain barrier (BBB) and the related medical needs, followed by a description of the methods currently applied for transport of drugs across the BBB. Then the structure, advantages and limitations of the most important lipidic-NCs applied for (targeted) delivery of drugs as well as nucleic acids are analyzed, and examples from recent reports for each NC type are mentioned. A brief description of the main diseases targeted is also included. Finally, the current limitations and future perspectives are summarized.