Assessment of enhancing curcumin's solubility versus uptake on its anti-cancer efficacy.

Curcumin (CUR) exhibits anti-inflammatory and anti-cancer activities. However, its poor solubility and bioavailability limit its therapeutic applications. Several CUR nano-formulations have been developed to enhance its solubility and uptake, thereby improving its anti-cancer activity. Despite this, studies comparing the effect of enhanced CUR solubility versus cellular uptake on its anti-cancer efficacy are lacking. Therefore, CUR nanofibers (CUR NF) were synthesized by electrospinning using a water-soluble polymer to enhance CUR solubility. While CUR nanoparticles (CUR NP) were synthesized by nanoprecipitation method using a water-insoluble polymer to enhance CUR cellular uptake. Both nano-formulations aim to improve CUR cellular concentration and anti-cancer activity against various cancer cells. CUR NF and CUR NP were successfully synthesized at drug load (DL%) of 10 %, 20 %, and 40 % w/w. Both nano-formulations were characterized, and CUR dissolution, release, cytotoxicity, IC50, and cellular uptake were assessed. A gradual increase in NF diameter and NP size was observed as the drug load% increased compared to the placebo. NF showed a rapid CUR release and increased solubility by 16-38 fold. In contrast, NP sustained CUR release and resulted in only a 2-fold increase in solubility. Both formulations significantly reduced cell viability and IC50 compared to free CUR. However, CUR NP demonstrated higher cell toxicity (70-80 %) than CUR NF (60 %) and reduced IC50 up to 4 µM compared to 11 µM for NF. Enhancing CUR solubility or uptake can significantly increase its cellular concentration and anti-cancer activity. However, enhancing CUR cellular uptake by NP demonstrated superior anti-cancer effect compared to enhancing its solubility by NF.

Smart optical sensing of multiple antibiotic residues from wastewater effluents with ensured specificity using SERS assisted with multivariate analysis.

Surface-enhanced Raman spectroscopy offers great potential for rapid and highly sensitive detection of pharmaceuticals from environmental sources. Herein, we investigated the feasibility of label-free sensing of antibiotic residues from wastewater effluents with high specificity by combining with multivariate analysis. Highly ordered silver nanoarrays with ∼34 nm roughness have been fabricated using a cost-effective electroless deposition technique. As-fabricated Ag arrays showed superior LSPR effects with an enhancement factor of 8 × 107. Excellent reproducibility has also been noticed with RSD values within 11%, whilst the sensor showed good stability and reusability characteristics for being used as a low-cost and reusable sensor. SERS studies demonstrated that antibiotics-spiked wastewater effluents can be detected with high efficiency in a label-free method. The molecular fingerprint bands of antibiotics such as sulfamethoxazole, sulfadiazine, and ciprofloxacin were well analyzed in effluent, tap, and deionized water. It has been found that antibiotics can be detected near picomolar levels; meanwhile, liquid chromatography-mass spectrometry (LC-MS) exhibited a detection limit within nanomolar concentrations only. Furthermore, the specificity of SERS sensing has been further analyzed using a multivariate analysis method, principal component analysis followed by linear discriminant analysis (PCA-LDA); which showed prominent discrimination to distinguish each antibiotic residue from wastewater effluents. The current study presented the potential of Ag nanoarray sensors for rapid, highly specific, and cost-effective analysis of pharmaceutical products for environmental remediation applications.