Development of Phosphatidylethanolamine Liposomes That Efficiently Retain Encapsulated Vinorelbine Bitartrate

A hydrophilic and temperature-induced degradation drug, vinorelbine bitartrate (VB)-loaded phosphatidylethanolamin sterically stabilized liposomes (PSLs) were prepared by the thin film hydration method. Liposomes were made of phosphatidylethanolamine: cholesteryl: oleic acid (PE: CHOL: OA, 6:4:3 mass/mass). The mean particle size of the PSLs ranged from 600 to 650 nm. The transmission electron microscope (TEM) images displayed that the shape of the PSLs was multilamellar vesicles with smooth surface. The highest entrapment efficiency (EE) and drug loading capacity (DL) could reach up to 81.2 and 16.6%, respectively. The studies of drug release showed that the drug release could last for much more than 48 hours. The PSLs was evaluated by comparing the rate of release of encapsulated VB in different phosphate buffer solution (PBS).     

Synthesis of Per- and Poly-Substituted Trehalose Derivatives: Studies of Properties Relevant to Their Use as Excipients for Controlled Drug Release

Per- and poly-substituted oligosaccharide derivatives, with trehalose cores, have been prepared and assessed for their potential for use as excipients in controlled-release formulations. The synthesized compounds, generally with acyl and amido substituents, included 6,6′-N,N′ -diamido-6,6′ -dideoxy-α,α -trehalose derivatives, 6,6′ -bis(1,2,3,4-tetra-O-acetyl-β -D-glucopyranuronyl)-α, α -trehalose derivatives, 2,2′,3,3′ -tetra-O-acetyl-6,6′ -bis-(1,2,3,4-tetra-O-acetyl-β-D-glucopyranuronyl)-4,4′ -di-O-acyl-α,α-trehalose, 2, 2′, 3, 3′ -tetra-O-acetyl-6-(1,2,3,4-tetra-O-acetyl-β-D-glucopyranuronyl)-4,4′,6′ -tri-O-acyl-α,α-trehalose, and 2,2′,3,3′,4,4′ -hexa-O-acetyl-6,6′ -bis-(1,2,3,4-tetra-O-acetyl-6-O-succinyl-β-D-glucopyranuronyl)-α,α-trehalose. Compounds were characterized by NMR, IR, MS and optical rotations; elemental analyses; or HRMS. The compounds formed amorphous materials either on fast quenching of melts or on spray drying. Properties, used in the initial assessment of the potential as controlled-release excipients, were log₁₀ P and glass transition, T_g, values.     

Covariate model-based fault tree analysis for risk assessment in chemical process industries: A case study of a chlorine manufacturing facility

Fault tree analysis (FTA) is a promising quantitative technique for risk analysis in chemical process industries (CPIs). In FTA, a certain sequence of basic events (causes) leads to one specific Top event (critical event of interest). However, the conventional fault tree analysis has the limitations of staticity and uncertainty. The staticity in conventional FTA arises due to its inability to accommodate time-dependent characteristics of the process system. Whereas uncertainty primarily lies in the failure probability data of basic events. This paper proposes an innovative methodology that uses a time-dependent covariate model to update the failure probability values of major contributing basic events in FTA. A novel subclass of the family of phase-type distributions is used to model the covariates corresponding to the basic events. The newly developed methodology is applied for a case study in a chlorine manufacturing facility to estimate the chlorine release probability. The blockage in the pipeline was identified as the significant reason for chlorine release from expert opinion and sensitivity analysis. The results of the proposed model of FTA are compared with that of conventional FTA.     

Light-Sensitive Phenacyl Crosslinked Dextran Hydrogels for Controlled Delivery**

Stimuli-responsive soft materials enable controlled release of loaded drug molecules and biomolecules. Controlled release of potent chemotherapeutic or immunotherapeutic agents is crucial to reduce unwanted side effects. In an effort to develop controlled release strategies that can be triggered by using Cerenkov luminescence, we have developed polymer hydrogels that can release bovine serum albumin and immunoglobulin G by using light (254 nm–375 nm) as a trigger. We describe the synthesis and photochemical characterization of two light sensitive phenacyl bis-azide crosslinkers that are used to prepare transparent self-supporting hydrogel patches. One crosslinker was designed to optimize the overlap with the Cerenkov luminescence emission window, bearing an π-extended phenacyl core, resulting in a high quantum yield (14 %) of photocleavage when irradiated with 375 nm light. We used the extended phenacyl crosslinker for the preparation of protein-loaded dextran hydrogel patches, which showed efficient and selective dosed release of bovine serum albumin or immunoglobulin G after irradiation with 375 nm light. Cerenkov-triggered release is as yet inconclusive due to unexpected side-reactivity. Based on the high quantum yield, efficient release and large overlap with the Cerenkov window, we envision application of these photosensitive soft materials in radiation targeted drug release.     

Structure and Performance Modulation of Self-Adhesive SIS/C5 Electrospun Membranes for Transdermal Drug Delivery北大核心CSCD

Electrospun membranes are widely utilized to enhance the water vapor permeability and drug delivery performance of transdermal drug delivery patches. Due to the lack of adhesion property,however,most of them cannot closely contact with skin,which impedes the delivery of drugs to the skin,thus affecting the transdermal administration. C5 resin is used to endow poly（styrene isoprene styrene）（SIS）electrospun membranes with pressure-sensitive adhesion property. Investigation is performed on how to control the structure,adhesion properties and drug delivery performance of SIS/C5 electrospun membranes loaded with synthetic capsaicin via compositions,drugs and electrospinning conditions. The results demonstrate that the electrospun membrane with a SIS/C5 ratio of 2∶1 has excellent water vapor permeability（7. 17×10－3 g/（h·cm2）and adhesion properties（180（°）peel strength is 0. 2 kN/m,tack force is 0. 64 N/cm2 ,holding power is greater than 7 days）. The synthetic capsaicin has good compatibility with the SIS/C5 electrospun membranes,in which no drug crystallizes and the drug loading is beneficial to improve the water vapor permeability. As the drug loading is 8%,the tack force is 0. 6～0. 8 N/cm2 ,the 180（°）peel strength is 0. 2～0. 3 kN/m,the holding power is greater than 7 days,and no residue is left during peeling tests. In vitro drug release indicates that the drug has a behavior of sustained release with a 24-hour cumulative release rate of greater than 50% for all SIS/ C5 electrospun membranes,meeting the requirements of transdermal drug delivery patches. © 2022, Science Press (China). All rights reserved.     

One step nanoencapsulation of corrosion inhibitors for gradual release application

The direct application of corrosion inhibitors on metal surfaces is potentially dangerous for the environment and the restoration operators, thus new conservation strategies are mandatory. In this study, two copper corrosion inhibitors, 1H-benzotriazole (BTA) and 5-phenyl-1H-tetrazole (PT), are encapsulated in a silica nanocontainer, for future application in smart coatings, with the aim to reduce the amount of chemicals used in treatments, their dispersion in the environment and the direct exposure of the operators to these chemicals. In particular, composite silica nanocapsules, containing the corrosion inhibitors, are prepared via one-step synthesis, based on mini-emulsion polymerisation processes.The morphology, structure, and texture of these loaded silica nanocontainers are characterised by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N₂ physisorption (BET/BJH). Micro-Raman spectroscopy (RS) is performed to characterise the composition. UV–visible spectroscopy and thermal analysis (TG/DSC) are performed for the loading and encapsulation efficiency (L%, EE%) study.Synthesised nanocapsules show a core-shell structure and, when loaded with the inhibitors, have size ranging from about 130 to 170 nm and a BET surface area of the order of 800 m²/g. The EE% is maximum in the case of BTA and decreases to ～52% in the case of PT.     

Smart Coatings Prepared via MAPLE Deposition of Polymer Nanocapsules for Light-Induced Release

Herein, smart coatings based on photo-responsive polymer nanocapsules (NC) and deposited by laser evaporation are presented. These systems combine remotely controllable release and high encapsulation efficiency of nanoparticles with the easy handling and safety of macroscopic substrates. In particular, azobenzene-based NC loaded with active molecules (thyme oil and coumarin 6) were deposited through Matrix-Assisted Pulsed Laser Evaporation (MAPLE) on flat inorganic (KBr) and organic (polyethylene, PE) and 3D (acrylate-based micro-needle array) substrates. SEM analyses highlighted the versatility and performance of MAPLE in the fabrication of the designed smart coatings. DLS analyses, performed on both MAPLE- and drop casting-deposited NC, demonstrated the remarkable adhesion achieved with MAPLE. Finally, thyme oil and coumarin 6 release experiments further demonstrated that MAPLE is a promising technique for the realization of photo-responsive coatings on various substrates.     

Quality-by-Design-Based Development of n-Propyl-Gallate-Loaded Hyaluronic-Acid-Coated Liposomes for Intranasal Administration

The present study aimed to develop n-propyl gallate (PG)-encapsulated liposomes through a novel direct pouring method using the quality-by-design (QbD) approach. A further aim was to coat liposomes with hyaluronic acid (HA) to improve the stability of the formulation in nasal mucosa. The QbD method was used for the determination of critical quality attributes in the formulation of PG-loaded liposomes coated with HA. The optimized formulation was determined by applying the Box–Behnken design to investigate the effect of composition and process variables on particle size, polydispersity index (PDI), and zeta potential. Physiochemical characterization, in vitro release, and permeability tests, as well as accelerated stability studies, were performed with the optimized liposomal formulation. The optimized formulation resulted in 90 ± 3.6% encapsulation efficiency, 167.9 ± 3.5 nm average hydrodynamic diameter, 0.129 ± 0.002 PDI, and −33.9 ± 4.5 zeta potential. Coated liposomes showed significantly improved properties in 24 h in an in vitro release test (>60%), in vitro permeability measurement (420 μg/cm²) within 60 min, and also in accelerated stability studies compared to uncoated liposomes. A hydrogen-peroxide-scavenging assay showed improved stability of PG-containing liposomes. It can be concluded that the optimization of PG-encapsulated liposomes coated with HA has great potential for targeting several brain diseases.     

Cationic and temperature-sensitive liposomes loaded with eugenol for the application to silk

Silk has been widely used in the clothing industry due to their soft and smooth features, good biocompatibility, good heat dissipation, warmth and ultraviolet resistance. The application of fragrance to silk can significantly improve the performance of silk. However, there are two key scientific problems that need to be solved: slowing down the release rate of fragrances and increasing the scent lasting time of silk. In this study, cationic and temperature-sensitive liposomes were designed and prepared to encapsulate eugenol. These fragrance-loaded liposomes significantly slowed down the release rate of the fragrance and controlled the release rate of the fragrance in a thermo-sensitive manner. The liposomes adhered to the silk through electrostatic adsorption interaction. The positive charge on the fragrance-loaded liposomes neutralized much negative charge on silk and thereby increasing the adhesion efficiency.