Lavandula stoechas extract incorporated polylactic acid nanofibrous mats as an antibacterial and cytocompatible wound dressing.

In recent years, great efforts have been devoted to the design and production of bioactive wound dressings that promote skin regeneration and prevent infection. Many plant extracts and essential oils have been widely accepted in traditional medicine for a wide variety of medicinal purposes, especially wound healing. Over the past decade, many studies have focused on manufacturing and designing wound dressings containing plant compounds and extracts. In this study, Lavandula stoechas extract (LSE) (0.25 %, 0.5 %, and 1%wt) incorporated-polylactic acid (PLA) nanofibrous mats were successfully produced and characterized. Microstructural analysis by SEM revealed that the fiber diameter changed with the increase in the amount of LSE. Also, the nanofibrous mats were evaluated for their in vitro antibacterial, cytotoxicity, and wound healing properties for their use as a wound dressing material. According to the results of the disc diffusion test, PLA nanofibrous mats containing LSE %1 showed 9.65 ± 0.46 and 7.37 ± 0.03 inhibition zone (mm) against E. coli and S. aureus, respectively. According to the results of the in vitro wound healing assay, mats containing 0.5 % LSE showed better-wound closure activity compared to the control. Our results show that LSE-incorporated nanofibrous dressings can be an effective alternative with good antimicrobial activity.

T-Shaped Microfluidic Junction Processing of Porous Alginate-Based Films and Their Characteristics.

In this work, highly monodisperse porous alginate films from bubble bursting were formed on a glass substrate at ambient temperature, by a T-shaped microfluidic junction device method using polyethylene glycol (PEG) stearate and phospholipid as precursors in some cases. Various polymer solution concentrations and feeding liquid flow rates were applied for the generation of monodisperse microbubbles, followed by the conversion of the bubbles to porous film structures on glass substrates. In order to compare the physical properties of polymeric solutions, the effects of alginate, PEG stearate (surfactant), and phospholipid concentrations on the flowability of the liquid in a T-shaped microfluidic junction device were studied. To tailor microbubble diameter and size distribution, a method for controlling the thinning process of the bubbles' shell was also explored. In order to control pore size, shape, and surface as well as internal structure morphologies in the scalable forming of alginate polymeric films, the effect of the feeding liquid's flow rate and concentrations of PEG-stearate and phospholipid was also studied. Digital microscopy images revealed that the as-formed alginate films at the flow rate of 100 µL·min-1 and the N2 gas pressure of 0.8 bar have highly monodisperse microbubbles with a polydispersity index (PDI) of approximately 6.5%. SEM captures also revealed that the as-formed alginate films with high PDI value have similar monodisperse porous surface and internal structure morphologies, with the exception that the as-formed alginate films with the help of phospholipids were mainly formed under our experimental environment. From the Fourier-transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) measurements, we concluded that no chemical composition changes, thermal influence, and crystal structural modifications were observed due to the T-shaped microfluidic junction device technique. The method used in this work could expand and enhance the use of alginate porous films in a wide range of bioengineering applications, especially in tissue engineering and drug delivery, such as studying release behaviors to different internal and surface morphologies.