Chemical and biological characterization of sulfated chitosan oligomer as heparin mimics

In the present study, chitosan oligomer was modified to sulfated chitosan oligomer (ShCsO) to mimic heparin. Its chemical structure was determined by infrared spectroscopy (FT-IR), X-ray diffractometry (XRD), differential scanning calorimetry (DSC), and thermogravimetric analysis. The results showed that the FT-IR spectrum band at 799 cm−1 corresponds to C–O–S and that at 1212 cm−1 corresponds to S=O bond stretching, which prove that the sulfate groups are incorporated into chitosan oligomer successfully. The antimicrobial activity of ShCsO against to Bacillus subtilis in 1% concentration was 89.1 ± 1.7% . The IC50 (μg/ml) of ShCsO was 67.75, 56.07, 85.47, and 84.68 for A2780, MCF-7, DU-145, and HepG2, respectively. The results show that this newly synthesized material is a potential candidate to heparin-like chitosan derivatives. According to the literature, it was the first time that chitosan oligomer was modified to mimic heparin.

Alginate gels crosslinked with chitosan oligomers – a systematic investigation into alginate block structure and chitosan oligomer interaction

Three alginates with different block structures, poly-M, poly-G, and poly-MG, were investigated upon ionic crosslinking with chitosan oligomers, using circular dichroism, rheology, and simulations, revealing a unique high gel strength poly-MG chitosan gelling system.

In Vitro Performance of Dutasteride-Nanostructured Lipid Carriers Coated with Lauric Acid-Chitosan Oligomer for Dermal Delivery

Dutasteride, licensed as an oral medicine for the treatment of benign prostatic hypoplasia, has been investigated as a treatment for androgenic alopecia. In this study, the potential for dustasteride to be delivered topically in order to reduce systemic exposure, irritation of the skin, and also cytotoxicity was explored. Chitosan oligomer (CSO) was successfully synthesised with lauric acid as a coating for a dutasteride-loaded nanostructured lipid carriers (DST-NLCs) system. DST-NLCs were prepared using a combination of melt-dispersion and ultrasonication. These negatively charged NLCs (−18.0 mV) had a mean particle size of ~184 nm, which was not significantly increased (p > 0.05) when coated with lauric acid-chitosan oligomer (CSO-LA), whilst the surface charge changed to positive (+24.8 mV). The entrapment efficiency of DST-NLCs was 97%, and coated and uncoated preparations were physically stable for up to 180 days at 4–8 °C. The drug release was slower from DST-NLCs coated with CSO-LA than from uncoated NLCs, with no detectable drug permeation through full-thickness pig ear skin from either preparation. Considering the cytotoxicity, the IC50 values for the DST-NLCs, coated and uncoated with CSO-LA were greater than for dutasteride alone (p < 0.05). DST-NLCs and empty NLCs coated with CSO-LA at 25 µM increased the cell proliferation compared to the control, and no skin irritation was observed when the DST-NLC formulations were tested using EpiDerm™. The cell and skin uptake studies of coated and uncoated NLCs incorporating the fluorescent marker Coumarin-6 showed the time-dependent uptake of Coumarin-6. Overall, the findings suggest that DST-NLCs coated with CSO-LA represent a promising formulation strategy for dutasteride delivery for the treatment of androgenic alopecia, with a reduced cytotoxicity compared to that of the drug alone and lower irritancy than an ethanolic solution of dutasteride.