No abstract

Statins [3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase, abbreviated HMGCR) inhibitors], are well-known cholesterol-depleting agents. Since the early 1990 s, it has been known that statins could be successfully used in cancer therapy, but the exact mechanism(s) of statin activity remains unclear and is now an extensive focus of investigation. So far, it was proven that there are several mechanisms that are activated by statins in cancer cells; some of them are leading to cell death. Statins exert different effects depending on cell line, statin concentration, duration of exposure of cells to statins, and the type of statin being used. It was shown that statins may inhibit the cell cycle by influence on both expression and activity of proteins involved in cell-cycle progression such as cyclins, cyclin-dependent kinases (CDK), and/or inhibitors of CDK. Also, statins may induce apoptosis by both intrinsic and extrinsic pathways. Statin treatment may lead to changes in molecular pathways dependent on the EGF receptor, mainly via inhibition of isoprenoid synthesis. By inhibition of the synthesis of cholesterol, statins may destabilize the cell membrane. Moreover, statins may change the arrangement of transporter OATP1, the localization of HMGCR, and could induce conformational changes in GLUT proteins. In this review, we have tried to gather and compare most of the recent outcomes of the research in this field. We have also attempted to explain why hydrophilic statins are less effective than hydrophobic statins. Finally, we have gathered results from in vivo experiments, presenting the use of statins in combined therapies and discussed a number of molecular targets that could serve as biomarkers predisposing to statin therapy.

Antisense gene therapy using molecules such as antisense oligodeoxynucleotides, siRNA or miRNA is a very promising strategy for the treatment of neoplastic diseases. It can be combined with other treatment strategies to enhance therapeutic effect. In acute leukemias, overexpression of the antiapoptotic gene BCL2 is observed in more than 70% of cases. Therefore, reduction of the Bcl-2 protein level could, in itself, prevent the development of cancer or could possibly help sensitize cancer cells to apoptosis inducers. The main objective of our work is to develop therapeutic liposome formulations characterized by high transfection efficiency, stability in the presence of serum, as well as specificity and toxicity for target (leukemic) cells. Each of our liposomal formulations consists of a core composed of antisense oligonucleotides complexed by either cationic lipid, DOTAP, or a synthetic polycation, polyethyleneimine, encapsulated within liposomes modified with polyethylenoglycol. In addition, the liposomal shells are enriched with covalently-bound antibodies recognizing a well characterized bio-marker, CD20, exposed on the surface of leukemia cells. The resulting immunoliposomes selectively and effectively reduced the expression of BCL2 in target cells. Model animal experiments carried out on mice-engrafted tumors expressing the specific marker showed high efficiency of the liposome formulations against specific tumor development. In conclusion, we show that lipid formulations based on a polyplex or lipoplex backbone additionally equipped with antibodies are promising non-viral vectors for specific oligonucleotide transfer into human tumor cells.

In this work, we present novel ex situ modification of bacterial cellulose (BC) polymer, that significantly improves its ability to absorb water after drying. The method involves a single inexpensive and easy-to-perform process of BC crosslinking, using citric acid along with catalysts, such as disodium phosphate, sodium bicarbonate, ammonium bicarbonate or their mixtures. In particular, the mixture of disodium phosphate and sodium bicarbonate was the most promising, yielding significantly greater water capacity (over 5 times higher as compared to the unmodified BC) and slower water release (over 6 times as compared to the unmodified BC). Further, our optimized crosslinked BC had over 1.5x higher water capacity than modern commercial dressings dedicated to highly exuding wounds, while exhibiting no cytotoxic effects against fibroblast cell line L929 in vitro. Therefore, our novel BC biomaterial may find application in super-absorbent dressings, designed for chronic wounds with imbalanced moisture level.

Herein we present an innovative method of coating the surface of Titanium-Aluminium-Niobium bone scaffold implants with bacterial cellulose (BC) polymer saturated with antibiotic. Customized Ti6Al7Nb scaffolds manufactured using Selective Laser Melting were immersed in a suspension of Komagataeibacter xylinus bacteria which displays an ability to produce a 3-dimensional structure of bio-cellulose polymer. The process of complete implant coating with BC took on average 7 days. Subsequently, the BC matrix was cleansed by means of alkaline lysis and saturated with gentamycin. Scanning electron microscopy revealed that BC adheres and penetrates into the implant scaffold structure. The viability and development of the cellular layer on BC micro-structure were visualized by means of confocal microscopy. The BC-coated implants displayed a significantly lower cytotoxicity against osteoblast and fibroblast cell cultures in vitro in comparison to non-coated implants. It was also noted that gentamycin released from BC-coated implants inhibited the growth of Staphylococcus aureus cultures in vitro, confirming the suitability of such implant modification for preventing hostile microbial colonization. As demonstrated using digital microscopy, the procedure used for implant coating and BC chemical cleansing did not flaw the biomaterial structure. The results presented herein are of high translational value with regard to future use of customized, BC-coated and antibiotic-saturated implants designed for use in orthopedic applications to speed up recovery and to reduce the risk of musculoskeletal infections.

There are many problems directly correlated with the systemic administration of drugs and how they reach their target site. Targeting promises to be a hopeful strategy as an improved means of drug delivery, with reduced toxicity and minimal adverse side effects. Targeting exploits the high affinity of cell-surface-targeted ligands, either directly or as carriers for a drug, for specific retention and uptake by the targeted diseased cells. One of the most important parameters which should be taken into consideration in the selection of an appropriate ligand for targeting is the binding affinity ( K D ). In this review we focus on the importance of binding affinities of monoclonal antibodies, antibody derivatives, peptides, aptamers, DARPins, and small targeting molecules in the process of selection of the most suitable ligand for targeting of nanoparticles. In order to provide a critical comparison between these various options, we have also assessed each technology format across a range of parameters such as molecular size, immunogenicity, costs of production, clinical profiles, and examples of the level of selectivity and toxicity of each. Wherever possible, we have also assessed how incorporating such a targeted approach compares with, or is superior to, original treatments.

fluorescent protein; HPC, hydrogenated egg phosphatidylcholine); pDNA, plasmid DNA; PE/PC, phosphatidylethanolamine and phosphatidylcholine liposomes; siRNA, small interferingRNA TGI, tumor growth inhibition.The chemical nature of genetic drugs (e.g. antisense oligonucleotides, siRNA, vectors) requires a suitable carrier system to protect them from enzymatic degradation without changing their properties and enable efficient delivery into target cells. Lipid vectors for nucleic acid delivery that have been widely investigated for years can be very effective. As the majority of attempts made in the field of cancer gene therapy have focused on solid tumors, while blood cancer cells have attracted less attention, the latter became the subject of our investigation. The lipid carrier proposed here is based on liposomes constructed by others but the lipid composition is original. A liposome-coated lipoplex (L-cL) consists of a core arising from complexation of positively charged lipid and negatively charged oligodeoxynucleotide (ODN) or plasmid DNA coated by a neutral or anionic lipid bilayer. Moreover, our lipid vector demonstrates size stability and is able to retain a high content of enclosed plasmid DNA or antisense oligodeoxynucleotides (asODNs). Observed transfection efficacies of the tested preparation using a plasmid coding for fluorescent protein were up to 60-85% of examined leukemia cells (Jurkat T and HL-60 lines) in the absence or the presence of serum. When BCL-2 asODN was encapsulated in the L-cL, specific silencing of this gene product at both the mRNA and protein level and also a markedly decreased cell survival rate were observed in vitro. Moreover, biodistribution analysis in mice indicates prolonged circulation characteristic for PEG-modified liposomal carriers. Experiments on tumor-engrafted animals indicate substantial inhibition of tumor growth.

Dendritic epidermal T cells (DETCs) represent a prototypical lineage of intraepithelial γδ T cells that participate in the maintenance of body barrier homeostasis. Unlike classical T cells, DETCs do not recirculate and they remain persistently activated through their T cell receptors (TCR) at steady state, i.e., in absence of infection or tissue wounding. The steady state TCR signals sustain the formation of immunological synapse-like phosphotyrosine-rich aggregates located on projections (PALPs) which act to anchor and polarize DETC’s long cellular projections toward the apical epidermis while the cell bodies reside in the basal layers. The PALPs are known to contain pre-synaptic accumulations of TCR-containing and lysosomal granules, but how this cargo accumulates there remains unclear. Here, we combined anti-Vγ5 TCR, cholera toxin subunit B (CTB), and LysoTracker (LT)-based intravital labeling of intracellular granules, with high resolution dynamic microscopy and fluorescence recovery after photobleaching (FRAP) to characterize the steady state composition and transport of DETC granules in steady state epidermis. Intradermal fluorescent Vγ5 antibody decorated DETCs without causing cellular depletion, dendrite mobilization or rounding up and became slowly internalized over 48 h into intracellular granules that, after 6 days, colocalized with LAMP-1 and less so with LT or early endosomal antigen-1. Intradermal CTB was likewise internalized predominantly by DETCs in epidermis, labeling a partly overlapping set of largely LAMP-1+ intracellular granules. These as well as LT-labeled granules readily moved into newly forming dendrites and accumulated at the apical endings. FRAP and spatiotemporal tracking showed that the inside tubular lengths of DETC cellular projections supported dynamic trafficking of lysosomal cargo toward and away from the PALPs, including internalized TCR and lipid raft component ganglioside GM1 (labeled with CTB). By contrast, the rate of GM1 granules transport through comparable dendrites of non-DETCs was twice slower. Our observations suggest that DETCs use chronic TCR activation to establish a polarized conduit system for long-range trans-epithelial transport aimed to accumulate mature lysosomes at the barrier-forming apical epidermis. The biological strategy behind the steady state lysosome polarization by DETCs remains to be uncovered.