Production of Low Molecular Weight Chitosan Using a Combination of Weak Acid and Ultrasonication Methods

Abstract

Low molecular weight chitosan (LMWC) has higher solubility and lower viscosity allowing for a wider pharmaceutical application compared to high molecular weight chitosan. LMWC chitosan can be obtained through a chitosan depolymerization process. This research aimed to produce LWMC using the combination of formic acid and ultrasonication method with the optimal condition of the depolymerization process. The chitosan depolymerization method was performed by combining formic acid and ultrasonication. The optimum conditions of the depolymerization process were obtained using the Box–Behnken design. The LMWC obtained from depolymerization was characterized to identify its yield, degree of deacetylation, the molecular weight, structure, morphology, thermal behavior, and crystallinity index. Results: The characterization results of LWMC obtained from the depolymerization process using the optimum conditions showed that the yield was 89.398%; the degree of deacetylation was 98.076%; the molecular weight was 32.814 kDa; there was no change in the chemical structure, LWMC had disorganized shape, there was no change in the thermal behavior, and LWMC had a more amorphous shape compared to native chitosan. Conclusion: The production of LWMC involving depolymerization in the presence of weak acid and ultrasonication can be developed by using the optimal condition of the depolymerization process.

Antibacterial, Anti-Biofilm and Pro-Migratory Effects of Double Layered Hydrogels Packaged with Lactoferrin-DsiRNA-Silver Nanoparticles for Chronic Wound Therapy

“…In Figure 3 C, the two peaks at 2 theta 9.64° and 20.99° that were present in the LTF spectrum became very weak once they complexed with AgNPs due to the crystal formation of the product via freeze-drying during the drying process [ 75 ]. The characteristic peaks of CS were also significantly decreased as a result of the complexation process with LTF due to its excellent sorption ability [ 76 ]. The highly deacetylated structure and low molecular weight of CS allow for the adsorption of hydrophilic moieties of LTF onto the hydroxyl and amine groups of CS [ 77 ].…”

Synthesis and characterization of chitosan for medical applications: A review

“…For example, high molecular weight chitosan may be more suitable for applications requiring strong mechanical properties, while low molecular weight chitosan may be preferred for improved biocompatibility or enhanced biological activity such as drug delivery. 82…”

“…85 Different acids may leave behind residues or impurities in the chitosan product. 82 For example, Hcl may leave chloride ions, while sulfuric acid may leave sulfate ions. These residual ions can affect the purity of chitosan and may have implications for biocompatibility and safety in medical applications.…”

“…61 However, the most used and important ones are, FTIR, viscometric analysis, AFM, XRD, NMR, and SEM. [79][80][81][82][83][84][85][86][87][88][89][90][91][80][81][82][83][84][85][86][87][88][89][90][91][92]…”

“…Strong acids may cause chain scission and degradation, resulting in lower molecular weight chitosan. 82 This may be desirable for some medical applications where lower molecular weight chitosan exhibits better solubility and bioavailability. The acid used can affect the crystallinity of chitosan.…”