Role of Ligand Conformation on Nanoparticle-Protein Interactions

Engineered biomedical nanoparticles (NPs) administered via intravenous routes are prone to associate to serum proteins. The protein corona can mask the NP surface functionalization and hamper the delivery of the NP to its biological target. The design of corona-free NPs relies on our understanding of the chemical-physical features of the NP surface driving the interaction with serum proteins. Here, we address, by computational means, the interaction between human serum albumin (HSA) and a prototypical monolayer-protected Au nanoparticle. We show that both the chemical composition (charge, hydrophobicity) and the conformational preferences of the ligands decorating the NP surface affect the NP propensity to bind HSA

Hyperthermic Perfusion 16 Years After its First Clinical Applications

It is known that above-normal temperatures (42°-42.5°C) provoke selective damage to neoplastic cells. We used heated circulating blood as a method for heat transfer on patients with limb tumors. From October 1964 to December 1979, we treated a total of 198 patients with hyperthermic perfusion for melanoma of the limbs (91), osteosarcoma (57), and soft tissue sarcoma (50). For melanoma patients, the five-year survival rate, excluding Stage IV, was 60%. For patients with soft tissue sarcoma, the five-year survival rates were 53% and 56% for hyperthermic perfusion and hyperthermic antiblastic perfusion. respectively. For 29 patients with osteosarcoma, hyperthermic perfusion was combined with systematic amputation ofthe limb for a 60% survival rate over a five-year period. Newer studies with osteosarcoma patients involve a multistep treatment that saves the tumor-bearing limb without reducing survival rates. Our 16-year clinical trial demonstrates that hyperthermia is effective in curing some tumors of the limbs, especially osteosarcoma and melanoma. We believe that perfusion remains the most reliable heat transfer method for loco-regional treatment and perhaps even for whole-body treatment for limb tumors

The influence of surfactants on the frog skin ion and water permeability

It is well known that sublethal doses of surfactants affect the cellular adhesion in the superficial layers of the exposed epithelia of aquatic animals, introducing a shunt in the active transport pathway, and that they are adsorbed by the cellular membranes, interacting with proteins and lipids and influencing the ion end water permeabilities. It has also been shown that the electrical behaviour of both the isolated and the \u201cin situ\u201d frog skin is heavily affected and that the isoosmotic, active transport coupled, water flow is abolished. We will propose a model for the toxic action of surfactants, based on the analysis of the decay of the electrical potential difference (pd) and short circuit current (scc), which accounts for the mentioned observations

Acetylenic alcohols as inhibitors of iron acid corrosion. Improvement of the inhibition efficiency of a class of substances based on their action mechanism

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Tear production, intraocular pressure, ultrasound biometric features and conjunctival flora identification in clinically normal eyes of two italian breeds of chicken (Gallus gallus domesticus)

Given the abundance of chickens in Italy, it is important for veterinarians to know the normal state of chickens’ eyes in order to identify any ophthalmic pathological changes. The aim of this study was to determine the normal values of select ocular parameters and to evaluate conjunctival microflora in two Italian chicken breeds. Sixty-six healthy chickens underwent a complete ophthalmic examination, which included a phenol red thread test (PRTT) for the evaluation of tear production and the assessment of intraocular pressure by rebound tonometry. B-mode ultrasound biometric measurements and conjunctival microflora identification were also performed in twenty-seven chickens. Mean PRTT was 23.77 ± 2.99 mm/15 s in the Livorno breed and 19.95 ± 2.81 mm/15 s in the Siciliana breed. Mean intraocular pressure was 14.3 ± 1.17 mmHg in the Livorno breed and 14.06 ± 1.15 mmHg in the Siciliana breed. Reference ranges for morphometric parameters were reported in the two breeds. Twenty-three chickens (85.18%) were bacteriologically positive. Chlamydia spp. antigen was detected in 14.81% of chickens. No positive cultures were obtained for fungi. Normal reference range values for selected ophthalmic parameters were obtained in clinically healthy chickens, which could facilitate accurate diagnosis and better management of ophthalmic diseases in these animals

Comparação dos sistemas intensivos de criação de suínos criados ao ar livre (SISCAL) e confinado (SISCO).

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Polystyrene perturbs the structure, dynamics, and mechanical properties of DPPC membranes: An experimental and computational study

Synthetic plastic oligomers can interact with the cells of living organisms by different ways. They can be intentionally administered to the human body as part of nanosized biomedical devices. They can be inhaled by exposed workers, during the production of multicomponent, polymer-based nanocomposites. They can leak out of food packaging. Most importantly, they can result from the degradation of plastic waste, and enter the food chain. A physicochemical characterization of the effects of synthetic polymers on the structure and dynamics of cell components is still lacking. Here, we combine a wide spectrum of experimental techniques (calorimetry, x-ray, and neutron scattering) with atomistic Molecular Dynamics simulations to study the interactions between short chains of polystyrene (25 monomers) and model lipid membranes (DPPC, in both gel and fluid phase). We find that doping doses of polystyrene oligomers alter the thermal properties of DPPC, stabilizing the fluid lipid phase. They perturb the membrane structure and dynamics, in a concentration-dependent fashion. Eventually, they modify the mechanical properties of DPPC, reducing its bending modulus in the fluid phase. Our results call for a systematic, interdisciplinary assessment of the mechanisms of interaction of synthetic, everyday use polymers with cell membranes

Towards a magnetoresistive platform for neural signal recording

A promising strategy to get deeper insight on brain functionalities relies on the investigation of neural activities at the cellular and sub-cellular level. In this framework, methods for recording neuron electrical activity have gained interest over the years. Main technological challenges are associated to finding highly sensitive detection schemes, providing considerable spatial and temporal resolution. Moreover, the possibility to perform non-invasive assays would constitute a noteworthy benefit. In this work, we present a magnetoresistive platform for the detection of the action potential propagation in neural cells. Such platform allows, in perspective, the in vitro recording of neural signals arising from single neurons, neural networks and brain slices