Polymer-based nanocapsules for drug delivery

Polymer nanoparticles: Preparation techniques and size-control parameters

Hydrogels for biomedical applications.

It is well known that urbanization and industrialization have resulted in the rapidly increasing emissions of volatile organic compounds (VOCs), which are a major contributor to the formation of secondary pollutants (e.g., tropospheric ozone, PAN (peroxyacetyl nitrate), and secondary organic aerosols) and photochemical smog. The emission of these pollutants has led to a large decline in air quality in numerous regions around the world, which has ultimately led to concerns regarding their impact on human health and general well-being. Catalytic oxidation is regarded as one of the most promising strategies for VOC removal from industrial waste streams. This Review systematically documents the progresses and developments made in the understanding and design of heterogeneous catalysts for VOC oxidation over the past two decades. It addresses in detail how catalytic performance is often drastically affected by the pollutant sources and reaction conditions. It also highlights the primary routes for catalyst deactivation and discusses protocols for their subsequent reactivation. Kinetic models and proposed oxidation mechanisms for representative VOCs are also provided. Typical catalytic reactors and oxidizers for industrial VOC destruction are further discussed. We believe that this Review will provide a great foundation and reference point for future design and development in this field.

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Recent Advances in the Catalytic Oxidation of Volatile Organic Compounds: A Review Based on Pollutant Sorts and Sources.

Poly-є-caprolactone based formulations for drug delivery and tissue engineering: A review

Although use of computational fluid dynamics (CFD) for simulating precipitation (and particulate systems in general) is becoming a standard approach, a number of issues still need to be addressed. One major problem is the computational expense of coupling a standard discretized population balance (DPB) with a CFD code, as this approach requires the solution of an intractably large number of transport equations. In this work the quadrature method of moments (QMOM) is tested for size-dependent growth and aggregation. The QMOM is validated by comparison with both Monte Carlo simulations and analytical solutions using several functional forms for the aggregation kernel. Moreover, model predictions are compared with a DPB to compare accuracy, computational time, and the number of scalars involved. Analysis of the relative performance of various methods for treating aggregation provides readers with useful information about the range of application and possible limitations.

Quadrature method of moments for population‐balance equations

In this work turbulent precipitation through solvent displacement for the production of poly-epsilon-caprolactone (PCL) nanoparticles is investigated; two different PCL molecular weights have been employed, using acetone and water as solvent and anti-solvent, respectively. The main important thermodynamic and kinetic parameters, such as solubility and interfacial tension of PCL in water-acetone mixtures, are determined and the effect of the process operating conditions on the final particle size distribution is also investigated. Particles produced under different conditions into a Confined Impinging Jets Reactor (CIJR) were characterized by Dynamic Light Scattering, Zeta potential measurements and Scanning Electronic Microscopy. Results clearly show the strong effect of mixing on the particle size distribution and how mixing must be controlled in order to obtain a product with particular characteristics. Eventually the measured thermodynamic and kinetic parameters are used to interpret the obtained experimental data.

Strategies to control the particle size distribution of poly-ε-caprolactone nanoparticles for pharmaceutical applications

In recent years there has been a growing interest in production on an industrial scale of particles with size in the sub-micron range (40-200 nm). This can be done by controlling particle formation in order to nucleate very small particles and by tailoring the particle surface in order to avoid particle aggregation and produce stable suspensions. In this work we focus on the role of turbulent mixing on particle formation in confined impinging jet reactors. In particular, we show how computational fluid dynamics and simple precipitation models could be used to derive scale-up criteria for the production of nanoparticles. © 2006 American Institute of Chemical Engineers AIChE J, 2006

Design and scale‐up of chemical reactors for nanoparticle precipitation

This paper is focused on the modelling of the primary drying of a lyophilization process in vials. A detailed mono-dimensional model taking into account mass and energy balances in the dried layer and at the sublimating interface, energy balance in the frozen layer and along the vial wall is set up; the mathematical model is validated using experimental data obtained in a pilot scale freeze-dryer, pointing out that the role of the glass wall can be relevant on the dynamics of the process. This model is suitable and has been used for off-line optimization; for on-line monitoring purposes, i.e. observer design, and for model-based control design such a detailed model is not useful, due to the high number of equations and of processes taken into consideration. Thus, two simplified models, that allow for analytical solution, have been developed: both models assume pseudo-stationary conditions because of the slow dynamics of the process, but while the first does not take into consideration the heat balance at the vial wall, this is explicitly considered in the second model. The results obtained with both models have been compared with the predictions of the detailed model for validation purposes.

Antonello Barresi

Papers

Quadrature method of moments for population‐balance equations

Strategies to control the particle size distribution of poly-ε-caprolactone nanoparticles for pharmaceutical applications

Design and scale‐up of chemical reactors for nanoparticle precipitation

Development of simplified models for the freeze-drying process and investigation of the optimal operating conditions

CFD modelling and scale-up of Confined Impinging Jet Reactors