Exploration of anti EFG1 locked nucleic acid gapmers to control Candida albicans filamentation

Introduction: Antisense oligonucleotides (ASOs) have been successfully utilized to silence gene expression for the treatment of many genetic human diseases, and particularly the locked nucleic acid (LNA) chemical modification is extensively used with this propose. However, LNA-modified ASOs have never been exploited for controlling virulence genes of Candida. EFG1is an important determinant of virulence that is involved in the switch from yeast to filamentous forms in C. albicans. Thus, our main goal was to explore LNA antisense gapmers for controlling EFG1gene expression and to block C. albicans filamentation. Methods: A set of five LNA-modified gapmers were designed with different chemical modifications (phosphorothioate backbone (PS) and/or palmitoyl-2’-amino-LNA) and ASO length. The in vitro performance of the different ASOs was evaluatedon their ability to control EFG1 gene expression, by qRT-PCR, and to reduce C. albicans’ filamentation, through filaments’ enumeration by microscopy. The in vivo therapeutic potential of ASOs was assessed using a G. mellonella model of infection, through a survival assay. Results: In vitro results showed that all ASOs were able to reduce the levels of EFG1gene expression, consequently reducing the levels of C. albicans filamentation around 50%. Interestingly, in vivo tests showed that the LNA-modified gapmer with PS backbone and palmitoyl-2’-amino-LNA was more effective at preventing G. mellonella infections. Conclusions: Undeniably, this work promotes the development of a novel approach for the treatment of Candida infections based on the delivery of ASOs coupled with LNA chemical modification.

An Update to Dialysis-Based Drug Release Testing—Data Analysis and Validation Using the Pharma Test Dispersion Releaser

Currently, a wide variety of complex non-oral dosage forms are entering the global healthcare market. Although many assays have been described in recent research, harmonized procedures and standards for testing their in vitro performance remain widely unexplored. Among others, dialysis-based techniques such as the Pharma Test Dispersion Releaser are developed for testing the release of drugs from nanoparticles, liposomes, or extracellular vesicle preparations. Here, we provide advanced strategies and practical advice for the development and validation of dialysis-based techniques, including documentation, analysis, and interpretation of the raw data. For this purpose, key parameters of the release assay, including the hydrodynamics in the device at different stirring rates, the selectivity for particles and molecules, as well as the effect of excipients on drug permeation were investigated. At the highest stirring rate, a more than twofold increase in the membrane permeation rate (from 0.99 × 10−3 to 2.17 × 10−3 cm2/h) was observed. Additionally, we designed a novel computer model to identify important quality parameters of the dialysis experiment and to calculate error-corrected release profiles. Two hydrophilic creams of diclofenac, Voltaren® Emulgel, and Olfen® gel, were tested and provide first-hand evidence of the robustness of the assay in the presence of semisolid dosage forms.

PVDF and P(VDF-TrFE) Electrospun Scaffolds for Nerve Graft Engineering: A Comparative Study on Piezoelectric and Structural Properties, and In Vitro Biocompatibility

Polyvinylidene fluoride (PVDF) and its copolymer with trifluoroethylene (P(VDF-TrFE)) are considered as promising biomaterials for supporting nerve regeneration because of their proven biocompatibility and piezoelectric properties that could stimulate cell ingrowth due to their electrical activity upon mechanical deformation. For the first time, this study reports on the comparative analysis of PVDF and P(VDF-TrFE) electrospun scaffolds in terms of structural and piezoelectric properties as well as their in vitro performance. A dynamic impact test machine was developed, validated, and utilised, to evaluate the generation of an electrical voltage upon the application of an impact load (varying load magnitude and frequency) onto the electrospun PVDF (15–20 wt%) and P(VDF-TrFE) (10–20 wt%) scaffolds. The cytotoxicity and in vitro performance of the scaffolds was evaluated with neonatal rat (nrSCs) and adult human Schwann cells (ahSCs). The neurite outgrowth behaviour from sensory rat dorsal root ganglion neurons cultured on the scaffolds was analysed qualitatively. The results showed (i) a significant increase of the β-phase content in the PVDF after electrospinning as well as a zeta potential similar to P(VDF-TrFE), (ii) a non-constant behaviour of the longitudinal piezoelectric strain constant d33, depending on the load and the load frequency, and (iii) biocompatibility with cultured Schwann cells and guiding properties for sensory neurite outgrowth. In summary, the electrospun PVDF-based scaffolds, representing piezoelectric activity, can be considered as promising materials for the development of artificial nerve conduits for the peripheral nerve injury repair.

Intermolecular Interactions and In Vitro Performance of Methyl Anthranilate in Commercial Sunscreen Formulations

In order to afford the required level of broad-spectrum photoprotection against UV-B and UV-A radiation, sunscreens must contain a combination of UV filters. It is important that any interactions between UV filters do not adversely affect their photostability nor the overall photostability of the sunscreen formulation. In this work, we explore the feasibility of using methyl anthranilate (MA) as an alternative to the photo-unstable UV-A filter, avobenzone. From the in vitro studies presented here, we conclude that MA does not provide sufficient UV-A protection on its own but that it is more photostable in formulation than avobenzone. In addition, we found that both octocrylene (OCR) and ethylhexyl methoxycinnamate (EHMC), two commonly used UV-B filters, can stabilize MA through quenching of its triplet states, as previously reported, which has a demonstrable effect in formulation. In contrast with previously reported observations for mixtures of EHMC and avobenzone, we found no evidence of [2+2] photocycloadditions taking place between EHMC and MA. This work demonstrates how a clear insight into the photophysics and photochemistry of UV filters, as well as the interactions between them, can inform formulation design to predict sunscreen performance.

The Mechanism of Improvement of Film Solubility: Design and Evaluation of Film Forming System with Terbinafine as a Model Drug

Purpose: Film forming system (FFS) combines the advantages of patch and gel, it is expected to replace small doses of topical administration in the future. This work targets the design and evaluation of HPC-acrylic FFS with different excipients in appearance, rheology and in vitro properties. Also, the reason of improving the solubility of terbinafine film was illustrated by melting enthalpy thermo analysis.Methods: In this work, we prepared 8 HPC-acrylic FFS samples with different excipients, and characterized the film forming solutions and films in appearance, rheological properties, drug crystallization and in vitro performance. Then used melting enthalpy thermo-analysis to explain the mechanism of improvement of film solubility.Results: According to appearance evaluation, the samples which had a small amount of plasticizer could achieve an uniform surface morphology. The XRD and DSC demonstrated HPC could maintain drug amorphous in films. Based on oscillation frequency sweep, short chain plasticizer tributyl citrate (TBC) leading to strong entanglement and hydrogen bonding among the molecules. In vitro release test showed FP1 had favorable release. And the melting enthalpy thermo-analysis explained why FP1 had favorable release. Conclusions: HPC acted as an effective crystallization inhibitor. TBC could lead stronger intermolecular hydrogen bonds. The poloxamer had favorite miscibility with HPC-acrylic FFS. The combination of MCT and poloxamer with HPC resulted in a high Terbinafine solubility.