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Treating inflammation with a dual-switch-controlled release system: The release of a drug from the developed microbead system occurs only in response to both an increase in local temperature and an acidic environmental pH. This dual-switch-controlled release system has the advantages of distinguishing between inflamed and healthy tissues to improve treatment efficacy., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Leroux et al. performed a set of experiments reported in our study and claim that they failed to reproduce the thermoresponsive liposomal system containing ammonium bicarbonate (ABC) that could trigger drug release under mild heating. We disagree with their assessments and speculate that the different method used by Leroux et al. to prepare the aqueous ABC is the culprit. [ABSTRACT FROM AUTHOR]

Abstract: Chitosan (CS), a cationic polysaccharide, is widely regarded as a safe and efficient intestinal absorption enhancer of therapeutic macromolecules, owing to its inherent mucoadhesive feature and ability to modulate the integrity of epithelial tight junctions reversibly. By using CS-based nanoparticles, many studies have attempted to protect the loaded macromolecules against acidic denaturation and enzymatic degradation, prolong their intestinal residence time, and increase their absorption by the intestinal epithelium. Derivatives of CS such as quaternized CS, thiolated CS and carboxylated CS have also been examined to further enhance its effectiveness in oral absorption of macromolecular drugs. This review article describes the synthesis of these CS derivatives and their characteristics, as well as their potential transport mechanisms of macromolecular therapeutics across the intestinal biological membrane. Recent advances in using CS and its derivatives as carriers for oral delivery of hydrophilic macromolecules and their effects on drug transport are also reviewed. [Copyright &y& Elsevier]