Concanavalin A (ConA) coated chitosan (CS) nanocarrier-DDS for antibiotic-resistant H. pylori

A group from Tissue Engineering and Regenerative Medicine Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran etc. has reported about a concanavalin A (ConA) coated chitosan (CS) nanocarrier-based drug delivery for the targeted release of peptides to the site of antibiotic-resistant H. pylori infection.

Helicobacter pylori is the cause of most cases of stomach ulcers and also causes some digestive cancers. The emergence and spread of antibiotic-resistant strains of H. pylori is one of the most important challenges in the treatment of its infections.

Chitosan was used as an encapsulating agent for CM11 peptide delivery by applying ionotropic gelation method. ConA was used for coating CS nanoparticles to target H. pylori. The size frequency for CS NPs and ConA-CS NPs was about 200 and 350 nm.

The Minimum Inhibitory Concentration (MIC) of the free CM11 peptide against drug-resistant H. pylori SS1 strain was 16 μg/ml while drug-resistant H. pylori SS1 showed MICs and MBCs 64 and >128 μg/ml against clarithromycin and amoxicillin, respectively. To encapsulate the peptide in nanoparticles, twice the MIC concentration of the peptide (32 µg/ml) was used.

CM11-loaded ConA-CS NPs has a higher antibacterial potential compared to the CM11-loaded CS NPs and free CM11 peptide, respectively. While there was no significant difference between the treatment with CM11-loaded ConA-CS NPs and triple antibiotics mixture, which indicates that it has the same effect similar to triple antibiotic therapy. CM11-loaded ConA-CS NPs and CM11-loaded CS NPs significantly reduced drug-resistant H. pylori SS1 after 12 h while amoxicillin and clarithromycin had no killing effect and their growth trend was same as the control group. The CM11-loaded ConA-CS NPs and triple antibiotics mixture were also able to kill drug-resistant H. pylori SS1 within 24 h while for free peptide and CM11-loaded CS NPs was after 48 h.