Chitosan-lactose (CHLac) derivatives obtained by Maillard reaction, characterization, physic-chemical properties and cytotoxicity activity.

ARATA BADANO J,; ROSSI Y; VANDEN BRABER N; BOHL L; PORPORATTO C; FALCONE RD; MONTENEGRO MA

Mar del Plata

Congreso; XVI Simposio Latinoamericano de Polímeros (SLAP 2018) y el IV Congreso Iberoamericano de Polímeros (CIP 2018).; 2018

INTRODUCTION: Chitosan (ChNat) is a linear polysaccharide formed by β-1→4 glucosamine and N-acetyl-glucosamine units derived from deacetylation of chitin. Is non-toxic, biocompatible, antioxidant, among other properties.1 Its widely used as carrier of drugs and bioactive agents in micro and nano-systems.2 However, uses of this polymer its limited because of its low solubility at neutral and alkaline pH. Therefore, extensive chemical modifications have been employed. Grafting with carbohydrates demonstrates to improved solubility since the incorporation of hydrophilic moieties. Maillard reaction (MR) is a non-enzymatic, intermolecular condensation reaction between amino and carbonyl groups. This reaction results an easy, eco-friendly and biocompatible way to obtain derivatives. Taking this background, modifications of ChNat using lactose (ChLac) have been proposal.EXPERIMENTAL METHODS: Synthesis. ChNat 1% (p/v) solutions in 1% (v/v) acetic acid was mixed with 1% (p/v) lactose. Solutions were stirred for 48 and 60 h at 70 °C. After, solutions were dialyzed (Mw cut-off 12?14 kDa) against water during 96 h at 4 °C and finally spay-dried. Solids were analyzed by infrared spectroscopy (FTIR). Molecular weight (MW). Was determined by static light scattering (SLS) using Debye approximation. Diluted solutions with concentration from 0.05 to 1.5 mg/mL were made optically clean by filtration through of 0.45 μm membrane. The dn/dc value for all samples in 1 (%v/v) CH3COOH aqueous solution was measured using a differential refractometer. Cytotoxicity activity. Rat intestinal epithelial cell line (IEC-18) were cultivated in DMEM supplemented with 10% fetal calf serum (FCS). In vitro cytotoxicity was evaluated by MTT assay. Cell viability (%) was calculated from the absorbance changes at 570 nm.RESULTS AND DISCUSSION: FT-IR spectra of Ch shows two bands at 1660 cm-1 and 1595 cm-1 corresponding to νC=O of amides and δN-H of amines respectively. Band at 1660 cm-1 shifts to 1630 cm-1 corresponding to νC=N, indicating imine formation. Band corresponding to δN-H shifts to 1560 cm-1, indicating Amadori?s rearrangement products. Comparing products spectra with of Ch, bands between 1000-1200 cm-1 show more intensity which corresponds with carbohydrates addition to chitosan structure. SLS results (Table 1) show a decrease in Mw of derivatives indicating hydrolytic behavior of MR and solubility was improved for both derivatives. G. Ying obtained similar results.CONCLUSION: In conclusion, ChNat derivatives have been obtained by MR with lower Mw. Cell viability has not been affected, indicating possible applications in biological systems.