Degradable Multilayer Films and Hollow Capsules via a ‘Click’ Strategy

Abstract

Degradable polymeric multilayer films and microcapsules are fabricated by ‘click’ chemistry using dextran modified with azide and alkyne moieties. Alternating layers of dextran modified with azide and alkyne groups, respectively, are covalently bonded by virtue of the 1,3‐dipolar cycloaddition reaction, known as click chemistry, which leads to the formation of stable triazole cross‐links between the successive layers. The dextran is modified in such a way that the azide and alkyne moieties are connected to the dextran backbone by a hydrolyzable carbonate ester. Therefore, the obtained multilayered structures can be degraded by simple hydrolysis. This type of multilayer avoids the use of polyelectrolytes, which are potentially cytotoxic, and could, therefore, be interesting for the fields of drug delivery and tissue engineering.magnified image

Polysaccharides: The “Click” Chemistry Impact

“…On the other hand, Bras and co-workers showed the feasibility of developing new materials from cellulose using a heterogeneous CuAAC reaction. The biodegradable [29] film consists in alternating layers of dextran modified with azide and alkyne groups. The dextran was modified in such a way that the azide and alkyne moieties were connected to the dextran backbone by a hydrolyzable carbonate ester function ( Figure 18).…”

1,3-Dipolar cycloadditions: applications to the synthesis of antiviral agents

“…Researchers working on strategies for developing antivirals 45 have tried to attack viruses at every stage of their life cycles, namely attachment to a host cell, replication of viral components, assembly of viral components into complete viral particles and release of viral particles able to infect new hosts cells. The present and the future of these antiviral tools has 50 been reported since the pharmacological point of view of pathogenic specific drugs such as amantidine, Tamiflu ® , and Relenza ® or ribavirin and interferons targeted against influenza or hepatitis C viruses, respectively.…”

“…To better understand the activity discrepancy of synthesised new inhibitors and zanamivir, the study was based on the crystal structure of neuraminidaseinhibitors derived from docking simulation. Whilst carboxylic 45 acid group of zanamivir formed strong hydrogen bonds with two arginine residues (Arg118, Arg371) in the S1 region and five hydrogen bond interactions in S2 region through the guanidinyl moiety, inhibitor…”

“…This carbonous 40 structure is bonded to the virus through an amino group of the native reactive lysines, and genetically inserted cysteines of the protein subunits arranged helically around genomic single RNA strand. 39 This binding caused degradation or variation of the stability of the viral peptides, which has been considered 45 of great interest for future investigations. Although they are not considered antiviral agents, there are another contributions dealing with the synthesis of very interesting useful molecules for the study of biomolecular recognition, binding mecanisms, etc.…”

From polymeric particles to multifunctional nanocapsules for biomedical applications using the miniemulsion process

“…174 Another method to release materials from a carrier is to apply shock waves (ultrasound). Goldenstedt et al encapsulated an active agent, ethyl benzoate, in gelatin-arabic gum (acacia)-based polymeric microcapsules by complex coacervation as already extensively described by Jegat and Taverde.…”