Effects of Magnetic Nanoparticles on the Functional Activity of Human Monocytes and Dendritic Cells

The use of nanoparticles in medicine is sometimes hampered by their potential to activate immune cells, eliciting inflammation or allergy. We investigated whether magnetic nanoparticles (MNPs) or biomimetic magnetic nanoparticles (BMNPs) affect relevant activities of human monocytes. We found that the nanoparticles neither elicited the production of pro-inflammatory mediators IL-6 and TNF by resting monocytes (when BMNP dose < 300 g/mL) nor enhanced their secretion induced by R848, a molecule engaging virus-recognizing receptors, or bacterial lipopolysaccharide (LPS). MNPs and BMNPs neither induced the generation of reactive oxygen species (ROS), nor affected the ROS production elicited by the NADPH oxidase activator phorbol myristate acetate (PMA) or the fungal derivative -glucan. BMNPs, but not MNPs, caused an up-regulation of the maturation markers CD80, CD83, and CD86 in immature monocyte-derived dendritic cells (DCs), whereas both nanoparticles did not affect the LPS-induced expression of these markers. Moreover, the nanoparticles were greedily ingested by monocytes and DCs without altering their viability. Therefore, these nanoparticles are candidates for medical applications because they do not activate pro-inflammatory activities of monocytes. Furthermore, their ability to stimulate DC maturation could be used for the design of vaccines. Moreover, harmlessly engulfed nanoparticles could be vehicles to carry molecules inside the immune cells to regulate the immune response.FUR (Fondo Unico della Ricerca-University of Verona)European Commission B-BIO-432-UGR20 Instituto de Salud Carlos III European Commission PI20-01658Spanish Government PDC2021-121135.100Ministerio de Universidades (Spain) FPU21_0152

Oxyresveratrol-Loaded PLGA Nanoparticles Inhibit Oxygen Free Radical Production by Human Monocytes: Role in Nanoparticle Biocompatibility

Oxyresveratrol, a polyphenol extracted from the plant Artocarpus lakoocha Roxb, has been reported to be an antioxidant and an oxygen-free radical scavenger. We investigated whether oxyresveratrol affects the generation of superoxide anion (O2 ) by human monocytes, which are powerful reactive oxygen species (ROS) producers. We found that oxyresveratrol inhibited the O2 production induced upon stimulation of monocytes with -glucan, a well known fungal immune cell activator. We then investigated whether the inclusion of oxyresveratrol into nanoparticles could modulate its effects on O2 release. We synthesized poly(lactic-co-glycolic acid) (PLGA) nanoparticles, and we assessed their effects on monocytes. We found that empty PLGA nanoparticles induced O2 production by resting monocytes and enhanced the formation of this radical in -glucan-stimulated monocytes. Interestingly, the insertion of oxyresveratrol into PLGA nanoparticles significantly inhibited the O2 production elicited by unloaded nanoparticles in resting monocytes as well as the synergistic effect of nanoparticles and -glucan. Our results indicate that oxyresveratrol is able to inhibit ROS production by activated monocytes, and its inclusion into PLGA nanoparticles mitigates the oxidative effects due to the interaction between these nanoparticles and resting monocytes. Moreover, oxyresveratrol can contrast the synergistic effects of nanoparticles with fungal agents that could be present in the patient tissues. Therefore, oxyresveratrol is a natural compound able to make PLGA nanoparticles more biocompatible

Porous silicon microparticles as efficient carriers for immunologic adjuvants

In this work we report a first-time combination of porous silicon (pSi) particles with the immunologic adjuvant Pam3CSK4, a TLR 1/2 agonist, as a tool for immunotherapy. pSi is a sponge-like biocompatible and biode gradable nanomaterial with high porosity, large surface-to-volume ratio and tunable surface, suitable for drug delivery applications. This study provides, by means of live-cell confocal microscopy, an insight about the time course of the interaction of free Pam3CSK4 vs vectorized by pSi microparticles with human dendritic cells (DCs). We found a delay in the ingestion of the agonist when carried by pSi microparticles. These findings were sup ported by the observation of the morphological changes related to the activation of DCs that occurred with a 5 h difference when treated with the vectorized ligand. These results provide the first demonstration of pSi as a conceivable candidate to deliver Pam3CSK4 to DCs paving the way towards immunotherapy practice

Oxyresveratrol Inhibits R848-Induced Pro-Inflammatory Mediators Release by Human Dendritic Cells Even When Embedded in PLGA Nanoparticles

Oxyresveratrol, a stilbene extracted from the plant Artocarpus lakoocha Roxb., has been reported to provide a considerable anti-inflammatory activity. Since the mechanisms of this therapeutic action have been poorly clarified, we investigated whether oxyresveratrol affects the release of the pro-inflammatory cytokines IL-12, IL-6, and TNF-\u3b1 by human dendritic cells (DCs). We found that oxyresveratrol did not elicit per se the release of these cytokines, but inhibited their secretion induced upon DC stimulation with R848 (Resiquimod), a well-known immune cell activator en-gaging receptors recognizing RNA viruses. We then investigated whether the inclusion of ox-yresveratrol into nanoparticles promoting its ingestion by DCs could favor its effects on cytokine release. For this purpose we synthesized and characterized poly(lactic-co-glycolic acid) (PLGA) nanoparticles, and we assessed their effects on DCs. We found that bare PLGA nanoparticles did not affect cytokine secretion by resting DCs, but increased IL-12, IL-6, and TNF-\u3b1 secretion by R848-stimulated DCs, an event known as \u201cpriming effect\u201d. We then loaded PLGA nanoparticles with oxyresveratrol and we observed that oxyresveratrol-bearing particles did not stimulate the cytokine release by resting DCs and inhibited the PLGA-dependent enhancement of IL-12, IL-6, and TNF-\u3b1 secretion by R848-stimulated DCs. The results herein reported indicate that oxyresveratrol suppresses the cytokine production by activated DCs, thus representing a good anti-inflammatory and immune-suppressive agent. Moreover, its inclusion into PLGA nanoparticles mitigates the pro-inflammatory effects due to cooperation between nanoparticles and R848 in cytokine release. Therefore, oxyresveratrol can be able to contrast the synergistic effects of nanoparticles with microorganisms that could be present in the patient tissues, therefore overcoming a condition unfavorable to the use of some nanoparticles in biological systems

Monocytes of Patients with Systemic Sclerosis (Scleroderma) Spontaneously Release In Vitro Increased Amounts of Superoxide Anion

It has been suggested that toxic oxygen free radicals can be involved in the pathogenesis of systemic sclerosis (scleroderma) (SSc). Because the cells that contribute to the generation of free radicals are not known, our aim was (i) to evaluate the ability of unmanipulated and phorbol 12-myristate 13-acetate-stimulated monocytes and polymorphonucleate neutrophils of SSc patients to generate superoxide anion (O2·–); and (ii) to investigate whether the O2·– produced by these cells involved the activation of nicotinamide-adenine dinucleotide diphosphate oxidase biochemical pathway. Employing the superoxide dismutase-inhibitable reduction of cytochrome c to evaluate the generation of O2·–, unmanipulated monocytes of SSc patients generated more O2·– than primary Raynaud’s phenomenon patients and normal control monocytes (p= 0.0001), and the release was higher in patients with diffuse cutaneous involvement and 5 y or less disease duration (p = 0.02). The involvement of nicotinamide-adenine dinucleotide diphosphate oxidase in the enhanced O2·– production was demonstrated by the finding that the cytosolic components of the enzyme, p47phox and p67phox, were both translocated to the plasma membrane of enriched but otherwise unmanipulated monocytes of SSc patients. The involvement of mitochondrial oxidases was excluded by the lack of inhibition of O2·– production when monocytes were incubated in the presence of rotenone, a mitochondrial oxidase inhibitor. Upon stimulation with phorbol 12-myristate 13-acetate, monocytes of SSc patients produced more O2·– than controls. In SSc patients untreated polymorphonucleate neutrophils generated significantly less O2·– than monocytes (p = 0.0001) and only slightly more than polymorphonucleate neutrophils of primary Raynaud’s phenomenon patients and normal controls (p = 0.03). In conclusion, we demonstrate that in patients with scleroderma, unmanipulated and phorbol 12-myristate 13-acetate-stimulated monocytes release in vitro increased amounts of superoxide anion through the activation of nicotinamide-adenine dinucleotide diphosphate oxidase and, thus, contribute to the oxidative stress found in this disease

The Two-Loop Finite-Temperature Effective Potential of the MSSM and Baryogenesis

We construct an effective three dimensional theory for the MSSM at high temperatures in the limit of large-$m_{A}$. We analyse the two-loop effective potential of the 3D theory for the case of a light right handed stop to determine the precise region in the $m_{h}$-$m_{\tilde{t}_{R}}$ plane for which the sphaleron constraint for preservation of the baryon asymmetry is satisfied. We also compare with results previously obtained usind 3D and 4D calculations of the effective potential. A two-stage phase transition still persists for a small range of values of $m_{\tilde{t}_{R}}$. The allowed region requires a value of m_{\tilde{t}_{R}} \lsi m_{t} and m_{h} \lsi 100 (110) GeV for $m_{Q} = 300$ GeV (1 TeV).Comment: 40 pages, 6 Postcsript figures, uses eps

Mixing Effects in the Finite-Temperature Effective Potential of the MSSM with a Light Stop

We incorporate the effects of mixing arising from the trilinear terms in the MSSM potential to the effective three dimensional theory for the MSSM at high temperature in the limit of large $m_{A}$. There are relevant one-loop effects that modify the 3D parameters of the effective theory. We calculate the two-loop effective potential of the 3D theory for the Higgs and the right handed stop to analyse the possible phase transitions and to determine the precise region in the $m_{h}$-$m_{\tilde{t}_{2}}$ plane for which the sphaleron constraint for preservation of the baryon asymmetry is satisfied. There is an upper bound on the value of the mixing parameter coming from stop searches. We also compare with previous results obtained using 4D calculations of the effective potential for the regime of large $m_{Q}$. A two-stage phase transition persists for a small range of values of $m_{\tilde{t}_{2}}$ for given values of the mixing parameter and $\tan\beta$. This can further constrain the allowed region of parameter space. Electroweak baryogenesis requires a value of m_{\tilde{t}_{2}}\lsi 170 and m_{h} \lsi 105 GeV for $m_{Q}=300$ GeV.Comment: 41 pages, 8 figure

Proinflammatory effects of bare and PEGylated ORMOSIL-, PLGA- and SUV-NPs on monocytes and PMNs and their modulation by f-MLP

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Insight into GEBR\u201032a: Chiral Resolution, Absolute Configuration and Enantiopreference in PDE4D Inhibition

Alzheimer\u2019s disease is the most common type of dementia, affecting millions of people worldwide. One of its main consequences is memory loss, which is related to downstream effectors of cyclic adenosine monophosphate (cAMP). A well\u2010established strategy to avoid cAMP degradation is the inhibition of phosphodiesterase (PDE). In recent years, GEBR\u201032a has been shown to possess selective inhibitory properties against PDE type 4 family members, resulting in an improvement in spatial memory processes without the typical side effects that are usually correlated with this mechanism of action. In this work, we performed the HPLC chiral resolution and absolute configuration assignment of GEBR\u201032a. We developed an efficient analytical and semipreparative chromatographic method exploiting an amylose\u2010based stationary phase, we studied the chiroptical properties of both enantiomers and we assigned their absolute configuration by 1H\u2010NMR (nuclear magnetic resonance). Lastly, we measured the IC50 values of both enantiomers against both the PDE4D catalytic domain and the long PDE4D3 isoform. Results strongly support the notion that GEBR\u201032a inhibits the PDE4D enzyme by interacting with both the catalytic pocket and the regulatory domains

Donor Cell Acute Myeloid Leukemia after Hematopoietic Stem Cell Transplantation for Chronic Granulomatous Disease: A Case Report and Literature Review

The patient reported here underwent hematopoietic stem cell transplantation (HSCT) due to chronic granulomatous disease (CGD) caused by biallelic mutations of the NCF1 gene. Two years later, he developed AML, which was unexpected and was recognized via sex-mismatched chromosomes as deriving from the donor cells; the patient was male, and the donor was his sister. Donor cell leukemia (DCL) is very rare, and it had never been reported in patients with CGD after HSCT. In the subsequent ten years, the AML relapsed three times and the patient underwent chemotherapy and three further HSCTs; donors were the same sister from the first HSCT, an unrelated donor, and his mother. The patient died during the third relapse. The DCL was characterized since onset by an acquired translocation between chromosomes 9 and 11, with a molecular rearrangement between the MLL and MLLT3 genes-a quite frequent cause of AML. In all of the relapses, the malignant clone had XX sex chromosomes and this rearrangement, thus indicating that it was always the original clone derived from the transplanted sister's cells. It exhibited the ability to remain quiescent in the BM during repeated chemotherapy courses, remission periods and HSCT. The leukemic clone then acquired different additional anomalies during the ten years of follow-up, with cytogenetic results characterized both by anomalies frequent in AML and by different, non-recurrent changes. This type of cytogenetic course is uncommon in AML