Design of a new light curable starch-based hydrogel drug delivery system to improve the release rate of quercetin as a poorly water-soluble drug.

In spite of quercetin advantages, its utilization as a cancer drug is confined due to its very low water solubility and bioavailability. Accordingly, we prepared a biodegradable starch-based hydrogel, using a new technique to control and improve quercetin release and bioavailability. For this purpose, the molecular structure of starch was modified by polyethylene glycol/acrylate and Fe3O4 nanoparticles were used to enhance mechanical properties of hydrogel. In order to prepare the final hydrogel drug carrier, the modified starch was directly mixed with quercetin and other additives in different ratios and cured under blue light. Synthesis confirmation and structural properties of the modified starch, silanized and pure Fe3O4 nanoparticles and final hydrogel were studied using 1H NMR, FT-IR, SEM, XRD, TGA, VSM and DLS analyses. We improved in vitro drug release to 56.62%, while the maximum release of quercetin from the starch-based hydrogel in our previous study was only 27% (Doosti et al., 2019).

Starch-based polyurethane/CuO nanocomposite foam: Antibacterial effects for infection control.

In the present study, a new method for the synthesis of the open cell flexible polyurethane foams (PUFs) was developed by using starch powder and the modification of closed cell foam formulation. Starch is the second largest polymeric carbohydrate as a macromolecule on this planet with a large number of glucose units. Copper oxide nanoparticles (CuO NPs) were synthesized by thermal degradation method at different temperatures of 400, 600 and 800 °C as antimicrobial agents. The antimicrobial activity of CuO NPs and commercial CuO powder against the main causes of hospital infections were tested. CuO600 was the most effective antimicrobial agent and enhanced polymer matrix tensile strength with starch powder as new polyurethane foams (PUFs) cell opener with high tensile strength. The effects of parameters on tensile strength were optimized using response surface methodology (RSM). CuO NPs and PUF had optimal conditions and were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Foam synthesized at the optimal conditions had an open cell structure with high tensile strength and efficient antimicrobial activity that made them suitable to be used as an antimicrobial hospital mattress to control hospital infections.