Development of Suberin Fatty Acids and Chloramphenicol-Loaded Antimicrobial Electrospun Nanofibrous Mats Intended for Wound Therapy

Suberin fatty acids (SFAs) isolated from outer birch bark were investigated as an antimicrobial agent and biomaterial in nanofibrous mats intended for wound treatment. Electrospinning (ES) was used in preparing the composite nonwoven nanomats containing chloramphenicol (CAM; as a primary antimicrobial drug), SFAs, and polyvinylpyrrolidone (as a carrier polymer for ES). The X-ray powder diffraction, differential scanning calorimetry, scanning electron microscopy, atomic force microscopy, and texture analysis were used for the physicochemical and mechanical characterization of the nanomats. ES produced nanofibrous mats with uniform structure and with an average fiber diameter ranging from 370 to 425 nm. Microcrystalline SFAs and crystalline CAM were found to undergo a solid-state transformation during ES processing. The ES process caused also the loss of CAM in the final nanofibers. In the texture analysis, the SFAs containing nanofibers exhibited significantly higher maximum detachment force to an isolated pig skin (p < 0.05) than that obtained with the reference nanofibers. CAM exists in an amorphous form in the nanofibers which needs to be taken into account in controlling the physical storage stability. In conclusion, homogeneous composite nanofibrous mats for wound healing can be electrospun from the ternary mixture(s) of CAM, SFAs, and polyvinylpyrrolidone.

Fast tablet tensile strength prediction based on non-invasive analytics

In this paper, linkages between tablet surface roughness, tablet compression forces, material properties, and the tensile strength of tablets were studied. Pure sodium halides (NaF, NaBr, NaCl, and NaI) were chosen as model substances because of their simple and similar structure. Based on the data available in the literature and our own measurements, various models were made to predict the tensile strength of the tablets. It appeared that only three parameters-surface roughness, upper punch force, and the true density of material-were needed to predict the tensile strength of a tablet. Rather surprising was that the surface roughness alone was capable in the prediction. The used new 3D imaging method (Flash sizer) was roughly a thousand times quicker in determining tablet surface roughness than traditionally used laser profilometer. Both methods gave practically analogous results. It is finally suggested that the rapid 3D imaging can be a potential in-line PAT tool to predict mechanical properties of tablets in production.

Immunomodulation by roquinimex decreases the expression of IL-23 (p19) mRNA in the brains of herpes simplex virus type 1 infected BALB/c mice

Herpes simplex virus (HSV) is a common neurotropic virus which infects epithelial cells and subsequently the trigeminal ganglia (TG) and brain tissue. We studied how immunomodulation with roquinimex (Linomide) affects the course of corneal HSV infection in BALB/c mice. BALB/c mice have also been used in a model for HSV-based vectors in treating an autoimmune disease of the central nervous system (CNS). We addressed the questions of how immunomodulation affects the local as well as the systemic immune response and whether roquinimex could facilitate the spread of HSV to the CNS. The cytokine response in the brain and TG was studied using a quantitative rapid real-time RT-PCR method. We were interested in whether immunomodulation affects the expression of the recently described Th1-cytokine IL-23p19 in the brain and TG. The expression of IL-23 mRNA was decreased in brains of roquinimex-treated BALB/c mice. Also the expression of IL-12p35 and IFN-gamma mRNAs decreased. No significant changes were seen in IL-4 and IL-10 mRNA expression. The cytokine response was also studied using supernatants of stimulated splenocytes by EIA. Roquinimex treatment suppressed the production of IFN-gamma and also the production of IL-10 in HSV-infected BALB/c mice.