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A local dyshomeostasis of zinc ions in the vicinity of amyloid aggregates has been proposed in Alzheimer’s disease (AD) due to the sequestration of zinc in senile plaques. While an increase in zinc levels may promote the aggregation of amyloid beta (Aβ), increased brain zinc might also be beneficial rescuing some pathological alterations caused by local zinc deficiency. For example, increased Aβ degradation by metalloproteinases, and a reduction in inflammation can be hypothesized. In addition, zinc may allow a stabilization of the number of synapses in AD brains. Thus, to evaluate whether altering zinc-levels within the brain is a promising new target for the prevention and treatment of AD, we employed novel zinc loaded nanoparticles able to deliver zinc into the brain across the blood-brain barrier. We performed in vivo studies using wild type (WT) and APP23 mice to assess plaque load, inflammatory status and synapse loss. Furthermore, we performed behavioral analyses. After chronically injecting these nanoparticles for 14 days, our results show a significant reduction in plaque size and effects on the pro-inflammatory cytokines IL-6 and IL-18. On behavioral level we could not detect negative effects of increased brain zinc levels in APP23 mice and treatment with g7-NP-Zn normalized the observed hyperlocomotion of APP23 mice. Therefore, we conclude that a targeted increase in brain zinc levels may have beneficial effects in AD. [ABSTRACT FROM AUTHOR]

Abstract: Poly-l-lactide (PLLA) is one of the most used polymers for biomedical application; its use in sutures and other implants has been widely investigated. Although the knowledge of PLLA biodegradation and biocompatibility features is deep, PLLA screws used to correct the flat foot deformity have deserved attention since they are not degraded in most of cases after a long period of years (3–7) from the implantation. In this article, a clinical and radiological evaluation (NMR, histological and clinical outcomes) on patients was correlated with physico-chemical characterization (by SEM, DSC, GPC and XRD analysis at different temperatures) on both native and patient-recovered screws together with the theoretical degradation processes of PLLA-based implants. The data demonstrated the need for crossing the biodegradation and bioabsorption of the polymer with the characteristics of both the device (geometry, structure and fabrication process) and the implantation site. [Copyright &y& Elsevier]

Abstract: Cationic solid lipid nanoparticles (SLN) are promising nonviral gene delivery carriers suitable for systemic administration. The objective of this study was to investigate the relationship between the composition of cationic SLN and their ability to condense plasmid DNA (pDNA) and to transfer it in neuroblastoma cells. The SLN were prepared by using stearic acid and stearylamine as lipid core along with Esterquart 1 (EQ1) or Protamine obtaining two samples (SLN-EQ1 and SLN-Protamine, respectively). The cationic SLN were freeze-dried after preparation and their physical–chemical properties, including the surface composition and the transfection efficiency were investigated. The results showed that the two samples had similar size, zeta potential and pDNA binding properties but SLN-Protamine were able to condense pDNA more efficaciously than SLN-EQ1 forming smaller and less positive complexes. SLN-Protamine:pDNA complexes demonstrated to be less cytotoxic and more efficient in the transfection of Na1300 cell line than SLN-EQ1:pDNA. These findings were attributed to the different surface composition of the two samples and in particular to the localization of the Protamine on the surface of the particle while EQ1 in the lipid core. In conclusion the results here suggest that not only the z-potential but also the surface composition may affect the pDNA condensation proprieties and thus the transfection efficiency of nonviral gene nanocarriers. [Copyright &y& Elsevier]

Abstract: This study aims to evaluate the effects of the two most widely used glycosaminoglycans (dermatan sulphate and heparin) on both the structural and biological properties of collagen-based modified membranes (COL/GAGs membranes) designed for tissue engineering. The molecular weight of dermatan sulphate and heparins was correlated with the membrane feasibility and the cell (fibroblasts and keratinocytes) ability to adhere and proliferate on the COL/GAG membranes. Microstructure and physico-chemical properties of COL/GAGs membranes were examined using scanning electron microscopy and differential scanning calorimetry; the free amino group content and the swelling properties were also detected. The morphology, proliferation and growth behaviour of keratinocytes and fibroblasts were investigated using microscopical approach and in vitro colorimetric assay. Both fibroblasts and keratinocytes are able to grow and proliferate on COL/dermatan sulphate membranes. Fibroblasts revealed significantly higher proliferation on the membranes prepared with heparin if compared to the proliferation on the membrane without heparin (COL membrane). Particularly, a combination of the membranes formulated adding high molecular weight dermatan sulphate and high molecular weight heparin could be suitable to be used as biomaterials for epidermal substitute. [Copyright &y& Elsevier]

Abstract: At present, liposomes play a significant role as drug delivery vehicles being considered very promising for gene therapeutics. The in vivo application of these drug delivery systems widely depends on their physico-chemical and technological characteristics such as the structure, the shape, the size distribution, the surface modification and the drug interaction. To describe the liposomes, different analytical techniques were used. In this paper, we reviewed the application of the atomic force microscopy (AFM), one of the most commonly applied scanning probe microscopy (SPM) techniques, in the description of liposome. The advantages and limitations of these techniques are discussed comparing the reported data with those referred to other well-know microscopical and spectroscopical techniques such as transmission electron microscopy (TEM) and photon correlation spectroscopy (PCS). A detailed description of the application of AFM to evaluate the formation and the geometry of liposomes/DNA complexes is presented. [Copyright &y& Elsevier]

Abstract: In this study we have investigated the chemical–physical and morphological properties of intact and atelocollagen sponges used for tissue engineering. The porous sponges were prepared by lyophilization and their physico-chemical characteristics (water binding capacity, denaturing temperature, amino group content) were investigated. Considering the importance of the “in vivo” interactions between these sponges and the tissue, our attention was addressed (a) to clarify the relationships between the morphology and the amount of water absorbed and (b) to evaluate the influence of pepsin-alkaline treatment on the reorganization of the atelocollagen fibres. Conventional scanning electron microscopy (SEM) and environmental scanning electron microscopy (ESEM) were employed to study the morphology and wetting behaviour of the intact and atelocollagen sponges. The observations by SEM indicated remarkable differences both in the structure and dimension of the pores between intact and atelocollagen sponges. At the data are related to a different water binding capacity. However, the ESEM observations, achieved by changing the relative humidity in the operative chamber, demonstrated that the water adsorbed can be removed with major difficulty from atelocollagen sponges than from intact ones. [Copyright &y& Elsevier]

Abstract: The relatively hydrophilic bile acid, ursodeoxycholic acid (UDCA), was used as an additive to DOTAP cationic liposomes to evaluate the effect on the cellular uptake of an oligonucleotide. Nuclear magnetic resonance studies were applied to estimate the relative amount of incorporated UDCA into the lipidic bilayers. DOTAP or DOTAP-UDCA vesicles (MixVes; DOTAP/UDCA molar ratios 1:0.25, 1:0.5, 1:1, and 1:2) formed complexes with 5′-fluorescein conjugated 29-mer phosphorothioate oligonucleotides (PS-ODNs) and studied using gel electrophoresis. In addition, the complexes were tested after transfection to assess the cellular uptake and the localization of the oligo in a HaCaT cell line by the use of cytofluorimetric and confocal microscopic analysis. DOTAP lipid formulated in the presence of a defined amount of UDCA forms more stable, flexible, and active MixVes. In particular, the MixVes at 1:0.25 and 1:0.5 molar ratios increase and modify the cellular uptake of PS-ODNs if compared with DOTAP liposomes 3 hours after the transfection studies. Moreover, the in vitro data suggest that these new formulations are not toxic. [Copyright &y& Elsevier]

Abstract: The direct evaluation of the heterogeneity of the particle population of nanometric drug delivery systems as liposomes is difficult to achieve owing to the dimension and the carrier characteristics. The influence of the lipidic ratio and composition on the physical stability of liposomes during their storage was investigated using atomic force microscopy (AFM) and photon correlation spectroscopy (PCS). Liposomes were made by a mixture of different lipids and obtained using distinct methods of preparation. AFM images, acquired immediately after the deposition of the sample on mica surface, clearly showed the spherical shape of the lipidic vesicles. In all the 7 months of the experiment, the average sizes of the different liposomes evaluated using the two techniques were comparable. According to PCS analysis, AFM images confirmed that almost all the diversified vesicular systems tended to form aggregates during their storage; this loss of stability was strengthened by the increase of polydispersity index value. The different behaviours observed were to ascribe to the lipidic composition more than the methods of liposome preparation. In conclusion, AFM technique owing to the relative simplicity cold be useful for the technological control of size distribution profile according to the preparative factors and moreover to the batch-to-batch reproducibility. [Copyright &y& Elsevier]

Central nervous system (CNS) compartments remain one of the most difficult districts for drug delivery. This is due to the presence of the blood–brain barrier (BBB) that hampers 90% of drug passage, dramatically requiring non-invasive treatment strategies. Here, for the first time, the use of opioid-derived deltorphin-derivative peptides to drive biodegradable and biocompatible polymeric (i.e. poly-lactide-co-glycolide, PLGA) nanomedicines delivery across the BBB was described. Opioid-derived peptides were covalently conjugated to furnish activated polymers which were further used for fluorescently tagged nanoformulations. Beyond reporting production, formulation methodology and full physico-chemical characterization, in vivo tests generated clear proof of BBB crossing and CNS targeting by engineered nanomedicines opening the research to further applications of drug delivery and targeting in CNS disease models. Overcoming most drugs' inability to cross the blood–brain barrier is the major challenge for treating CNS diseases. Deltorphin peptides, with their unique 3D structure, can act as ligand drivers to let nanomedicines cross and transport across the BBB. In this work new PLGA nanoparticles conjugated with deltorphin-derived peptides were shown to be able to cross BBB and localize in the CNS parenchyma. Unlabelled Image • Overcoming BBB crossing challenges for the treatment of CNS diseases • Engineerable PLGA nanoparticles • Tailored PLGA nanomedicines with BBB crossing ligands for CNS drug delivery systems • Deltorphins cross the BBB and are used as "drivers" for tailored nanomedicines • Technological, chemical and pharmaceutical characterization of deltorphins • Deltorphin opioid derivative targeting ligands that don't trigger opioid responses • In vivo, engineered NPs cross the BBB and localize to the CNS parenchyma [ABSTRACT FROM AUTHOR]

Restoration of the Chol homeostasis in the Central Nervous System (CNS) could be beneficial for the treatment of Huntington’s Disease (HD), a progressive, fatal, adult-onset, neurodegenerative disorder. Unfortunately, Chol is unable to cross the blood–brain barrier (BBB), thus a novel strategy for a targeted delivery of Chol into the brain is highly desired. This article aims to investigate the production of hybrid nanoparticles composed by Chol and PLGA (MIX-NPs) modified with g7 ligand for BBB crossing. We described the impact of ratio between components (Chol and PLGA) and formulation process (nanoprecipitation or single emulsion process) on physico-chemical and structural characteristics, we tested MIX-NPs in vitro using primary hippocampal cell cultures evaluating possible toxicity, uptake, and the ability to influence excitatory synaptic receptors. Our results elucidated that both formulation processes produce MIX-NPs with a Chol content higher that 40%, meaning that Chol is a structural particle component and active compound at the same time. The formulation strategy impacted the architecture and reorganization of components leading to some differences in Chol availability between the two types of g7 MIX-NPs. Our results identified that both kinds of MIX-NPs are efficiently taken up by neurons, able to escape lysosomes and release Chol into the cells resulting in an efficient modification in expression of synaptic receptors that could be beneficial in HD. [ABSTRACT FROM AUTHOR]

[Display omitted] • Reliability of Quality by Design approach in design/optimization of nanomedicine. • Stability study on optimized nanomedicine was carried out according to ICH QA(R2) guidelines resulting stable up to 6 months under refrigerated storage conditions. • Combining mucus penetrating effect and positive charges to increase mucoadhesion in ocular delivery by hybrid nanomedicine. • Neuroprotective and antioxidant effects in an in vitro model of diabetic retinopathy. • Ocular tolerability proven by a modified Draize Test. Melatonin (MEL) is a pleiotropic neurohormone of increasing interest as a neuroprotective agent in ocular diseases. Improving the mucoadhesiveness is a proposed strategy to increase the bioavailability of topical formulations. Herein, the design and optimization of MEL-loaded lipid-polymer hybrid nanoparticles (mel-LPHNs) using Design of Experiment (DoE) was performed. LPHNs consisted of PLGA-PEG polymer nanoparticles coated with a cationic lipid-shell. The optimized nanomedicine showed suitable size for ophthalmic administration (189.4 nm; PDI 0.260) with a positive surface charge (+39.8 mV), high encapsulation efficiency (79.8 %), suitable pH and osmolarity values, good mucoadhesive properties and a controlled release profile. Differential Scanning Calorimetry and Fourier-Transform Infrared Spectroscopy confirmed the encapsulation of melatonin in the systems and the interaction between lipids and polymer matrix. Biological evaluation in an in vitro model of diabetic retinopathy demonstrated enhanced neuroprotective and antioxidant activities of mel-LPHNs, compared to melatonin aqueous solution at the same concentration (0.1 and 1 μM). A modified Draize test was performed to assess the ocular tolerability of the formulation showing no signs of irritation. To the best our knowledge, this study reported for the first time the development of mel-LPHNs, a novel and safe hybrid platform suitable for the topical management of retinal diseases. [ABSTRACT FROM AUTHOR]

The hydrophilic ion paring strategy (HIP) is a method explored to improve the cell/tissue uptake of poorly adsorbed drugs and to optimize their physico-chemical characteristics. In this context, we here describe the synthesis of some ion pairs of two model cationic antibiotics, erythromycin (ERY) and kanamycin A (KAN), with liposaccharides having different levels of lipophilicity and charge. The formation of drug-liposaccharide complexes was confirmed by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD) analysis. The effect of the amphiphilic liposaccharide moieties on the antimicrobial activity of ERY and KAN was assessed by measuring the minimal inhibitory concentration (MIC) of the compounds against a panel of bacterial strains that were susceptible or resistant to the parent antibiotics. The ion pairing did not depress the in vitro antibiotic activity, although no lowering of MIC values was registered. The experimental findings would motivate the future investigation of this ion pairing strategy in drug design, for instance allowing improvement of the encapsulation efficiency of hydrophilic antibiotics in lipid-based nanocarriers, or changing their in vivo biodistribution and pharmacokinetic profile. [ABSTRACT FROM AUTHOR]

Silencing of the B lymphocyte-induced maturation protein 1 (Blimp-1), a pivotal transcriptional regulator during terminal differentiation of B cells into plasma cells with siRNAs is under investigation as novel therapeutic approach in Primary Effusion Lymphoma (PEL), a HHV-8 related and aggressive B cell Lymphoma currently lacking of an efficacious therapeutic approach. The clinical application of small interfering RNA (siRNA) in cancer therapy is limited by the lack of an efficient systemic siRNA delivery system. In this study we aim to develop pegylated siRNA lipoplexes formed using the cationic lipid DOTAP and DSPE-PEG 2000 , capable to effectively stabilize anti-Blimp-1 siRNA and suitable for systemic administration. Two types of pegylated lipoplexes using a classic (C-PEG Lipoplexes) or a post-pegylation method (P-PEG-Lipoplexes) were formulated and compared in their physicochemical properties (size, zeta potential, morphology and structure) and efficiency on PEL cell lines. A stable siRNAs protection was obtained with post pegylation approach (2% molar of DSPE-PEG 2000 with respect to lipid) resulting in structures with diameters of 300 nm and a complexation efficiency higher that 80% (0.08 nmol/10 nmol of lipid). In vitro studies on PEL cell lines suggested that empty liposomes were characterized by a low cell toxicity also after PEG modification (cell viability and cell density over 85% after treatment with 10 μM of lipid). We demonstrated that P-PEG-Lipoplexes were able to significantly reduce the levels of BLIMP-1 protein leading to reduction of viability (less that 15% after transfection with 100 nM of complexed siRNAs) and activation of apoptosis. In vitro efficiency encourages us to further test the in vivo potential of P-PEG-Lipoplexes in PEL therapy. [ABSTRACT FROM AUTHOR]

Highlights: [•] Formulation of PEG-lipoplexes efficient in siRNA stabilization. [•] Spectroscopic-electrophoretic and microscopic analyses of lipoplexes. [•] Use of “phase” AFM and TEM to detect local properties of lipoplexes surface. [•] Predictive methods to evaluate lipoplexes applicability. [ABSTRACT FROM AUTHOR]

Abstract: Tenofovir (PMPA), an acyclic nucleoside phosphonate analog, is one of the most important drugs used for the HIV treatment. Unfortunately, several adverse reactions are related to its i.v. administration owing to the saturation of an anionic renal transporter. In order to improve the drug administration, the PMPA was embedded into a new type of nanocarriers based on poly-(d,l-lactide-co-glycolide) (PLGA) and/or chitosan (CH). The strategies for the preparation of nanoparticles (Nps) with a more efficient drug loading respect to the one reported in the literature for PMPA nanoencapsulation were investigated. CH was added in the first inner emulsion or in the external phase during the second emulsion of water/oil/water (W/O/W) Nps. The addition of CH in the first inner emulsion was the most promising technique. The Nps have a Z-average of 230nm, a Z-potential of −3mV and an EE% of 15 that was 2.5–3 times higher than that obtained with PLGA Nps or CH Nps. In vitro release studies showed a limited control on drug release in phosphate buffer (pH 7.4) while an initial burst effect followed by a slow drug release was observed in acidic receiving phase (pH 4.6). These results suggest the PLGA/CH Nps should be an effective and attractive anti-HIV drug carrier to study the cellular uptake and drug delivery on target cells such as macrophages. [Copyright &y& Elsevier]

Abstract: Cidofovir is an antiviral drug active as antitumoral agent a high doses against the Primary Effusion Lymphoma, a herpesvirus HHV8-associated B-cell lymphoma. A novel polymeric/lipidic hybrid system, consisting in a specific combination of biocompatible materials, capable to build a crossbred between polymeric particles and liposomes were prepared and used to stabilize and deliver the drug, unsuccessfully formulated into several types of carriers. This innovative cidofovir-delivering system has structurally been characterized in comparison to multilamellar liposomes and polymeric particles, and then tested for antitumoral efficacy against tumor cells (BCBL-1 cell line). The results demonstrated the improving of drug stability and encapsulation efficiency and suggested that polymeric/lipidic hybrid system could be promising to improve the antitumoral effect of cidofovir even at lower doses. [Copyright &y& Elsevier]

Abstract: A series of amphiphilic ion pairs of the aminoglycoside antibiotic tobramycin (TOB) with lipoamino acids (LAA) bearing an alkyl side chain of 10–14 carbon atoms are described. TOB-LAA ion pairs were obtained by reduced pressure evaporation of an aqueous-ethanol co-solution of TOB and LAAs. A different degree of substitution of TOB amine groups was obtained by using increasing the drug to LAA molar fractions (1:1 to 1:5). FTIR analysis corroborated their structure, powder X-ray diffractometry (PXRD) and differential scanning calorimetry (DSC) were used to identify the formation of new chemical species. The prepared compounds were submitted to an in vitro microbiological assay against different bacterial strains, both susceptible and resistant to aminoglycosides. The presence of only one LAA moiety did not improve the in vitro antibacterial activity of TOB free base. Analogously, equimolar physical mixtures (PhM) of TOB with LAA failed to exert a remarkable cell growth inhibitory activity. Noteworthy, when three or all the five amine groups of TOB were salified with LAA residues, very active compounds were produced, showing MIC values lower than the detectable limit of 0.03 μg/ml. [Copyright &y& Elsevier]

New approaches integrating stimuli-responsive linkers into prodrugs are currently emerging. These "smart" prodrugs can enhance the effectivity of conventional prodrugs with promising clinical applicability. Oxidative stress is central to several diseases, including cancer. Therefore, the design of prodrugs that respond to ROS stimulus, allowing a selective drug release in this condition, is fairly encouraging. Aiming to investigate the ROS-responsiveness of prodrugs containing the ROS-cleavable moiety, Thioketal (TK), we performed proof-of-concept studies by synthesizing ROS-responsive conjugate, namely mPEG-TK-Cy5, through exploiting Cy5 fluorescent dye. We demonstrated that, differently to non-ROS-responsive control conjugate (mPEG-Cy5), mPEG-TK-Cy5 shows a selective release of Cy5 in response to ROS in both, ROS-simulated conditions and in vitro on glioblastoma cells. Our results confirm the applicability of TK-technology in the design of ROS-responsive prodrugs, which constitutes a promising approach in cancer treatment. The translatability of this technology for other diseases treatment makes this a highly relevant and promising approach. [ABSTRACT FROM AUTHOR]