Publications in March 2017 - antimicrobial activity of chitosan

In March 2017, 215 articles were released about chitosan and chitosan derivatives. The top three nations in chitosan research are China (59), India (32) and USA (27). Main focuses were nanoparticels, evaluation studies and pharmaceutical preparations.

Top Journals	Publications
International Journal of Biological Macromolecules	36
Scientific Reports	7
Materials Science and Engineering	7
ACS applied materials & interfaces	6
European Journal of Pharmaceutical Sciences	6

Table: Top 5 scientific journals, which published chitosan-related articles in march 2017.
Source: GoPubMed

Controlled drug delivery is a critical step for efficient disease treatment. The following two studies present how drug delivery systems can benefit of chitosan for treatment of infections and wound healing.

Chitosan-Based Nanomedicine to Fight Genital Candida Infections: Chitosomes.

Andersen, T.; Mishchenko, E.; Flaten, et al.; Mar. Drugs 15(3), 64, März 2017

Successful therapy of vaginal Candida infection requires the synergistic treatment of several pathogens, particularly fungi and bacteria. Chitosan has antimicrobial activity, especially antifungal activity against Candida species and studies revealed the ability of chitosan, to prevent and disrupted biofilms of C. albicans. Mucoadhesive properties support the application of chitosan as drug delivery system targeting the vaginal site.
In this study, chitosan-containing liposomes (chitosomes) were loaded with an antimicrobial drug called metronidazole to enable a synergistic approach in the therapy of vaginal infection. To prove the beneficial effect of chitosan, the mucoadhesive polymer Carbopol was used as control. Carbopol is commonly used as drug delivery system in different therapeutic areas, including vaginal therapy sites. To generate Polymer-Liposomes a dispersion of soy phosphatidylcholine and metronidazole was injected into an aqueous solution of chitosan or Carbopol. Liposomes were coated with polymers at the surface and additionally inside the aqueous compartment of the liposomes to facilitate sufficient drug loading (see illustration above).
Chitosan-, Carbopol-containing liposomes and plain liposomes were characterized with regard to optimal vesicular size, surface properties and drug load, as well as in vitro release.

RESULTS:

• Sonicated chitosan-containing liposomes were smaller than Carbopol-containing liposomes (smaller vesicle size are expected to have better distribution at the infected site)
• Polymer-containing liposomes had a higher entrapment efficiency of metronidazol
• Prolonged release of metronidazole by all three liposomal formations was acceptable in vitro
• Antifungal Activity: Only chitosan-containing liposomes (empty and metronidazole loaded) inhibited the growth of C. albicans

Conclusion: C. albicans growth was inhibited exclusively by chitosan-containing liposomes independently of the antibacterial drug metronidazole. The synergistic approach of antifungal activity of chitosan (77% degree of deacetylation) combined with the antibacterial effect of metronidazole could improve treatment of mixed vaginal infections and prevent recurrence.

Fulltext available: Source: https://www.ncbi.nlm.nih.gov/pubmed/28273850

Sequential delivery of chlorhexidine acetate and bFGF from PLGA-glycol chitosan core-shell microspheres.

Chen M. M., Cao H., Liu Y.Y. et al.; Colloids Surf B Biointerfaces, Vol. 151, March 2017

Aim of the study was the development of a drug delivery system for sequential release of antibacterial drugs and growth factors to promote wound healing. Microspheres with a biodegradable poly(lactic-
co-glycolic acid) (PLGA) core and glycol chitosan (GC) shell were generated. The model drug chlorhexidine acetate (CHA) and basic fibroblast growth factor (bFGF) were integrated in the microsphere shell and core, respectively. Size, sequential drug and protein release, as well as antimicrobial and proliferative promoting effects of the PLGA-GC core-shell microspheres were characterized.

RESULTS:

• Rapid release of CHA in contrast to sustained protein release
• GC amount could influence release capacity
• Suitable assays proved antimicrobial effects of CHA and proliferation induction of 3T3 cells by bFGF
• Produced microspheres waren non-cytotoxic and biocompatible against 3T3 cells
• Effectiveness of CHA/bFGF was not negatively influenced by the manufacturing procedure of the microspheres

Conclusion: PLGA-glycol chitosan core-shell microspheres could be a promising drug delivery system in wound treatment. Rapid release of antimicrobial CHA could prevent wound infection, whereas the sustained release of growth factors promotes cell proliferation and therefore wound healing.

Source: https://www.ncbi.nlm.nih.gov/pubmed/28012407