Protein-loaded PLGA–PEO blend nanoparticles: encapsulation, release and degradation characteristics

The aim of this work was to study the variables that affect the encapsulation and release of proteins from nanoparticles based on poly(lactic-co-glycolic acid; PLGA)–poloxamer and PLGA–poloxamine blend matrices, using bovine serum albumin (BSA) and immuno-γ-globulin (IgG) as model proteins. The nanoparticles were prepared by a solvent diffusion technique, and the studied variables were (1) PLGA molecular weight, (2) type of PEO-block copolymers, (3) protein loading, (4) pH and, (5) volume of the protein solution. Our results showed that the proteins can be efficiently incorporated into and released from the blend matrices. The type of the PEO derivative and the pH of the internal aqueous phase were the most important factors influencing protein encapsulation and release kinetics. Moreover, comparative degradation study of PLGA, PLGA–poloxamer and PLGA–poloxamine nanoparticles confirmed that the degradation and release characteristics of polyester particles can be improved by the incorporation of polyoxyethylene derivatives with different hydrophilia–lipophilia balance.     

Integrated microfluidic platform for the electrochemical detection of breast cancer markers in patient serum samples

A microsystem integrating electrochemical detection for the simultaneous detection of protein markers of breast cancer is reported. The microfluidic platform was realized by high precision milling of polycarbonate sheets and features two well distinguishable sections: a detection zone incorporating the electrode arrays and the fluid storage part. The detection area is divided into separate microfluidic chambers addressing selected electrodes for the measurement of samples and calibrators. The fluidic storage part of the platform consists of five reservoirs to store the reagents and sample, which are interfaced by septa. These reservoirs have the appropriate volume to run a single assay per cartridge and are manually filled. The liquids from the reservoirs are actuated by applying a positive air pressure (i.e.via a programmable syringe pump) through the septa and are driven to the detection zone via two turning valves. The application of the realised platform in the individual and simultaneous electrochemical detection of proteic cancer markers with very low detection limits are demonstrated. The microsystem has also been validated using real patient serum samples and excellent correlation with ELISA results obtained.     

Mathematical justification of a nonlinear integro-differential equation for the propagation of spherical flamesJustification mathématique d'une équation intégro-différentielle non linéaire pour un modèle de flamme sphérique

This Note is devoted to the justification of an asymptotic model for quasisteady three-dimensional spherical flames proposed by G. Joulin [7]. The paper [7] derives, by means of a three-scale matched asymptotic expansion, starting from the classical thermo-diffusive model with high activation energies, an integro-differential equation for the flame radius. In the derivation, it is essential for the Lewis number – i.e., the ratio between thermal and molecular diffusion – to be strictly less than unity. In this Note, we give the main ideas of a rigorous proof of the validity of this model, under the additional restriction that the Lewis number is close to 1. To cite this article: C. Lederman et al., C. R. Acad. Sci. Paris, Ser. I 334 (2002) 569–574.     

Pyrazolo[3,4-d][1,2,3]triazolo[1,5-a]pyrimidine: a new ring system through Dimroth rearrangement

Derivatives of the new ring system pyrazolo[3,4-d][1,2,3]triazolo[1,5-a]pyrimidine were synthesized from the corresponding angular isomers, through a Dimroth rearrangement, in quantitative yields. Preliminary computational studies demonstrated that this class of compounds could be a good candidate as DNA intercalating agents.     

Recent Advances in Recovery of Lycopene from Tomato Waste: A Potent Antioxidant with Endless Benefits

Growing attention to environmental protection leads food industries to adopt a model of “circular economy” applying safe and sustainable technologies to recover, recycle and valorize by-products. Therefore, by-products become raw material for other industries. Tomato processing industry produces significant amounts of by-products, consisting of skins and seeds. Tomato skin is very rich in lycopene, and from its seeds, high nutritional oil can be extracted. Alternative use of the two fractions not only could cut disposal costs but also allow one to extract bioactive compounds and an oil with a high nutritional value. This review focused on the recent advance in extraction of lycopene, whose beneficial effects on health are widely recognized.     

Nonlinear asset-price dynamics and stabilization policies

Nonlinear Dynamics - We first present a brief review of nonlinear asset-pricing models and contributions in which such models have been used as benchmarks to evaluate the effectiveness of a number...     

A minimum problem with free boundary in Orlicz spaces

We consider the optimization problem of minimizing in the class of functions W1,G(Ω) with , for a given φ₀?0 and bounded. W1,G(Ω) is the class of weakly differentiable functions with . The conditions on the function G allow for a different behavior at 0 and at ∞. We prove that every solution u is locally Lipschitz continuous, that it is a solution to a free boundary problem and that the free boundary, Ω∩∂{u>0}, is a regular surface. Also, we introduce the notion of weak solution to the free boundary problem solved by the minimizers and prove the Lipschitz regularity of the weak solutions and the C1,α regularity of their free boundaries near “flat” free boundary points.     

Convergent assembly of highly potent analogues of bryostatin 1 via pyran annulation: bryostatin look-alikes that mimic phorbol ester function

Highly potent bryostatin analogues which contain the complete bryostatin core structure have been synthesized using a pyran annulation approach as a key strategic element. The A ring pyran was assembled using a pyran annulation reaction between a C1-C8 hydroxy allylsilane and an aldehyde comprising C9-C13. This pyran was transformed to a new hydroxy allylsilane and then coupled with a preformed C ring aldehyde subunit in a second pyran annulation, with concomitant formation of the B ring. This tricyclic intermediate was elaborated to bryostatin analogues which displayed nanomolar to subnanomolar affinity for PKC, but displayed properties indistinguishable from a phorbol ester in a proliferation/attachment assay.