Myricetin loaded in solid lipid nanoparticles induces apoptosis in the HT-29 colorectal cancer cells via mitochondrial dysfunction

BACKGROUND

Among the flavonoids, Myricetin (MCN) has negligible side effects and anti-cancer properties. However, the therapeutic potential of MCN has been limited mainly by its low bioavailability. Nanocarriers improve the bioavailability and stability of flavonoids. The toxic effects of MCN loaded in solid lipid nanoparticles (MCN-SLNs) on the HT-29 human colorectal cancer cells were investigated in this study.

METHODS AND RESULTS

HT-29 cells were exposed to the 30 µmol MCN or MCN-SLNs for 24 h. Colony formation, cell viability, apoptosis, and expression of the Bax, Bcl-2, and AIF (apoptosis-inducing factor) have been investigated. Mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) generation were also measured. The MCN-SLNs with appropriate characteristics and a slow sustained MCN release until 48 h made. MCN-SLNs could diminish colony numbers and survival of the HT-29 cells. The apoptosis index of MCN-SLNs-treated cells significantly increased compared to the free MCN (p < 0.001). The expression of Bax and AIF were elevated (p < 0.01 and p < 0.001, respectively) while Bcl-2 expression was decreased in MCN-SLNs treatment (p < 0.05). Moreover, MCN-SLNs significantly enhanced the ROS formation and reduced MMP compared to the free MCN-treated cells (p < 0.01).

CONCLUSIONS

The SLN formulation of MCN can effectively induce colon cancer cell death by raising ROS formation and activating the apoptosis process.

Fabrication and Characterization of Glycerol/Chitosan/Polyvinyl Alcohol-Based Transparent Hydrogel Films Loaded with Silver Nanoparticles for Antibacterial Wound Dressing Applications

Background

Wounds have a bad prognostic nature and excessive discharges whose regular wound dressings are ineffective. Hydrogels are the best candidates for dressing such wounds due to their high water content and ability to exchange substances. Accordingly, the purpose of this study was to make a novel hydrogel wound dressing following the integration of various findings on wound healing and the use of regenerative medicine.

Materials and Methods

Various compounds were fabricated by glycerol/chitosan/polyvinyl alcohol (PVA) and then characterized to obtain the optimal composition using several techniques, including a water vapor passage test, scanning electron microscopy, water absorption, tensile strength, biodegradability, Fourier transform infrared spectroscopy, and antibacterial test.

Results

The findings revealed the optimal dressing ratio. Better antibacterial activity was found for the silver nanoparticle (AgNP) dressing.

Conclusion

Our new fabricated dressing, glycerol/chitosan/PVA hydrogel loaded with AgNPs, exhibited satisfactory wound healing properties.

Nanoscale plasmonically enhanced photodetector based on a gold nanoring

A nanoscale germanium-gold Schottky photodetector (PD) is proposed based on a nanoring supporting localized surface plasmon excitation. A design methodology is presented based on maximizing resonant transmission power throughput of light from the active region of the PD. Numerical calculations show significant field enhancement of about 200 times in the near-field zone inside of the nanoring, which is utilized to compensate the responsivity decrease due to PD active region volume shrinkage, providing the responsivity of 338  mA/W at a 1310 nm detection wavelength. In addition, the incident wavelength is detected in about one-seventh of the absorption length of bulk germanium, yielding about 33% of the external quantum efficiency. The ratio of responsivity to the active region volume of the PD is calculated to be approximately 100 times that of similar studies.

Modeling and analysis of optical properties of a gold nanoring based on electric and magnetic dipoles

The optical behavior of a plane-wave excited gold nanoring (NR), originated from localized surface plasmon resonance is modeled by two coupled electric- and magnetic-point dipoles. Considering the extinction cross-section spectrum, it is found that the electric-dipole effect is dominant in comparison with the magnetic-dipole effect although the magnetic-dipole signature is observable in the near-field response of the NR. In addition, the far-field electromagnetic radiation pattern of the NR verifies the corresponding radiation pattern of the point dipoles. The numerical simulation near-field results are in agreement with the proposed electric- and magnetic-dipole theory.