Thermodynamic and Kinetic Aspects Involved in the Development of Nanocarriers and Drug Delivery Systems Based on Cationic Biopolymers

BIANCO ISMAEL; ALASINO ROXANA; VICTORIA LEONHARD; BELTRAMO DANTE MIGUEL

CURRENT PHARMACEUTICAL DESIGN.

BENTHAM SCIENCE PUBL LTD

Lugar: Oak Park; Año: 2016

1381-6128

Abstract: During the last years we have seen an increasing number of reports describing new properties and potentialapplications of cationic polymers and derived nanostructures. This review gives a summary of their applicationsin drug delivery, the preparation methods for nano and microstructures and will attempt to give a glimpse onhow their structure, chemical composition and properties may be affected or modulated as to make them suitablefor an intended application as drug delivery nanocarriers. The compositional complexity with the existence of severalreacting groups makes cationic nanostructures critically sensitive to the contribution of thermodynamic and kineticparameters in the determination of the type and stability of a particular structure and its ability to respond tochanges in environmental conditions in the right time frame. Curiously, and contrarily to what could be expected, despite the fact thatcationic polymers can form strong electrostatic interactions the contribution of the entropic component has been often found to be veryimportant for their association with negatively charged supramolecular structures. Some general considerations indicate that when consideringa complex multimolecular system like a nanocarrier containing an active ingredient it is frequently possible to find conditionsunder which enthalpic and entropic contributions are compensated leading to stable structures with a marginal thermodynamic stability(free energy change close to zero) which make them able to respond relatively fast to changes in the environmental conditions and thereforesuitable for the design of smart drug delivery systems. Like with other nanocarriers, it should always be kept in mind that the propertiesof cationic nanocarriers will depend not only on their chemical composition but also on the properties of the structures formed bythem.