Electrospun Nanofibers Loaded with Marigold Extract Based on PVP/HPßCD and PCL/PVP Scaffolds for Wound Healing Applications.

Marigold flower is a traditionally used plant material topically applied on the skin due to its anti-inflammatory properties and antibacterial activity. This potential of action justifies the implementation of marigold extract in nanofiber scaffolds based on poly-vinylpyrrolidone/hydroxypropyl-ß-cyclodextrin (PVP/HPßCD) and polycaprolactone/polyvinylpyrrolidone (PCL/PVP) obtained by electrospinning for wound treatment. Using SEM, the morphology of electrospun scaffolds showed a fiber diameter in the range of 298-527 nm, with a uniform and bead-free appearance. ATR-FTIR spectroscopy confirmed the presence of marigold extracts in nanofibrous scaffolds. The composition of the nanofibers can control the release; in the case of PVP/HPßCD, immediate release of 80% of chlorogenic acid (an analytical and functional marker for marigold extract) was achieved within 30 min, while in the case of PCL/PVP, the controlled release was achieved within 24 h (70% of chlorogenic acid). All systems showed weak antibacterial activity against skin and wound-infecting bacteria Staphylococcus aureus (MIC 100 mg/mL), and Pseudomonas aeruginosa (MIC 200 mg/mL) and yeasts Candida albicans (MIC 100 mg/mL). Analysis of the effect of different scaffold compositions of the obtained electrofibers showed that those based on PCL/PVP had better wound healing potential. The scratch was closed after 36 h, compared to the 48 h required for PVP/HPßCD. Overall, the study shows that scaffolds of PCL/PVP nanofibers loaded with classic marigold extract have the best potential as wound dressing materials because of their ability to selectively modulate inflammation (via inhibition of hyaluronidase enzyme) and supportive antimicrobial properties, thereby aiding in the early stages of wound healing and repair.

Anti-Aging Properties of Chitosan-Based Hydrogels Rich in Bilberry Fruit Extract.

Photoaging is a process related to an increased level of reactive oxygen species (ROS). Polyphenols can scavenge free radicals in the body, which can delay skin aging. Therefore, our work aimed to prepare a biologically active extract from dry fruits of Vaccinium myrtillus or Vaccinium corymbosum and use it for the preparation of hydrogels for topical application. Therefore, eight different extracts (using V. myrtillus and V. corymbosum and different extraction mixtures: methanol, methanol-water 1:1, water, acetone-water 1:1) were prepared and their phytochemical (total polyphenolic content, total flavonoid content, total anthocyanin content) and biological properties (antioxidant, anti-hyaluronidase, and anti-tyrosinase activity) were assessed. Cytotoxicity towards HaCaT keratinocytes was also determined. Based on the results, the acetone-water extract from V. myrtillus was selected for further study. Using the Design of Experiments approach, chitosan-based hydrogels with bilberry fruit extract were prepared. The content of extract and chitosan were selected as independent factors. The activity of hydrogels depended on the extract content; however, the enzyme-inhibiting (anti-hyaluronidase and anti-tyrosinase) activity resulted from the presence of both the extract and chitosan. Increased concentration of chitosan in the hydrogel base led to increased viscosity of the hydrogel and, consequently, a slower release of active compounds. To get optimal hydrogel characteristics, 1% extract and 2.5% MMW chitosan were utilized. The research suggests the validity of using bilberry fruit extracts in topical preparations with anti-aging properties.

Selective Encapsulation of the Polyphenols on Silk Fibroin Nanoparticles: Optimization Approaches.

The present study proposes a method for designing small bioactive nanoparticles using silk fibroin as a carrier to deliver hydrophobic polyphenols. Quercetin and trans-resveratrol, widely distributed in vegetables and plants, are used here as model compounds with hydrophobic properties. Silk fibroin nanoparticles were prepared by desolvation method and using various concentrations of ethanol solutions. The optimization of the nanoparticle formation was achieved by applying Central Composite Design (CCD) and the response surface methodology (RSM). The effects of silk fibroin and ethanol solution concentrations together with the pH on the selective encapsulation of phenolic compounds from a mixture were reported. The obtained results showed that nanoparticles with an average particle size of 40 to 105 nm can be prepared. The optimized system for the selective encapsulation of the polyphenols on the silk fibroin substrate was determined to be 60% ethanol solution and 1 mg/mL silk fibroin concentration at neutral pH. The selective encapsulation of the polyphenols was achieved, with the best results being obtained in the case of resveratrol and quercetin and encapsulation of gallic and vanillic acids being rather poor. Thin-layer chromatography confirmed the selective encapsulation and the loaded silk fibroin nanoparticles exhibited antioxidant activity.