Long-term Room Temperature Storage Research Articles

Thermally Robust Solvent-Free Liquid Polyplexes for Heat-Shock Protection and Long-Term Room Temperature Storage of Therapeutic Nucleic Acids.

Nucleic acid therapeutics have attracted recent attention as promising preventative solutions for a broad range of diseases. Nonviral delivery vectors, such as cationic polymers, improve the cellular uptake of nucleic acids without suffering the drawbacks of viral delivery vectors. However, these delivery systems are faced with a major challenge for worldwide deployment, as their poor thermal stability elicits the need for cold chain transportation. Here, we demonstrate a biomaterial strategy to drastically improve the thermal stability of DNA polyplexes. Importantly, we demonstrate long-term room temperature storage with a transfection efficiency maintained for at least 9 months. Additionally, extreme heat shock studies show retained luciferase expression after heat treatment at 70 °C. We therefore provide a proof of concept for a platform biotechnology that could provide long-term room temperature storage for temperature-sensitive nucleic acid therapeutics, eliminating the need for the cold chain, which in turn would reduce the cost of distributing life-saving therapeutics worldwide.

Supercooled sugar alcohols stabilized by alkali hydroxides for long-term room-temperature phase change solar-thermal energy storage

Seasonal thermal energy storage within organic phase change materials (PCMs) offers a promising way to solve intermittency of renewable energy, but the charged PCMs tend to undergo spontaneous crystallization and lose the stored latent heat to cold environment during storage. Herein, we report introduction of alkali hydroxides into sugar alcohols to increase the activation energy barrier for liquid-to-solid phase transition and stabilize the supercooling state, thereby realizing long-term phase change thermal energy storage. Owing to increased intermolecular hydrogen bonding interaction, the charged composites can maintain the supercooled state and conserve latent heat (∼200 J/g) during storage at room temperature or extremely cold temperatures for months. Further compounding with polydopamine organic pigments, the composites demonstrate high solar absorptance (∼91.6 %) and thus enable seasonable storage of solar-thermal energy as latent heat at room temperature. The stored heat can be readily released through adding seed crystals or applying mechanical deformation, which triggers cold crystallization of the supercooled composites and releases latent heat within a suitable temperature range of 40–60 °C. Such phase change composites not only eliminate complicated thermal insulation engineering required in conventional long-term thermal storage processes, but also unlock diverse application opportunities for thermal energy systems.

Optimization of Biocompatibility for a Hydrophilic Biological Molecule Encapsulation System.

Despite considerable advances in recent years, challenges in delivery and storage of biological drugs persist and may delay or prohibit their clinical application. Though nanoparticle-based approaches for small molecule drug encapsulation are mature, encapsulation of proteins remains problematic due to destabilization of the protein. Reverse micelles composed of decylmonoacyl glycerol (10MAG) and lauryldimethylamino-N-oxide (LDAO) in low-viscosity alkanes have been shown to preserve the structure and stability of a wide range of biological macromolecules. Here, we present a first step on developing this system as a future platform for storage and delivery of biological drugs by replacing the non-biocompatible alkane solvent with solvents currently used in small molecule delivery systems. Using a novel screening approach, we performed a comprehensive evaluation of the 10MAG/LDAO system using two preparation methods across seven biocompatible solvents with analysis of toxicity and encapsulation efficiency for each solvent. By using an inexpensive hydrophilic small molecule to test a wide range of conditions, we identify optimal solvent properties for further development. We validate the predictions from this screen with preliminary protein encapsulation tests. The insight provided lays the foundation for further development of this system toward long-term room-temperature storage of biologics or toward water-in-oil-in-water biologic delivery systems.

Effects of Carriers on ANAMMOX Sludge Activity Recovery and Microbial Flora Characteristics

In order to realize the rapid recovery of ANAMMOX sludge bacterial activity after long-term room temperature storage, three groups of reactors were added to ANAMMOX sludge that had been stored without substrate at room temperature (15-30℃) for 9 months. Among the three groups of reactors, comet fiber carrier and K3 carrier were added to R2 and R3 reactors, respectively, as biological carriers. The effects of different carriers on the recovery rate of ANAMMOX sludge bacterial activity were investigated. The results showed that ANAMMOX reactions in the R2 and R3 reactors began taking place on the 8th and 10th day, respectively, with respective TIN removal rates of 82.25% and 80.92%, which were significantly improved compared with that in the R1 reactor, in which no carrier was added (ANAMMOX reaction started occurring on the 15th day with a TIN removal rate of 80.26%). After 42 days with influent, ρ(NH4+-N) and ρ(NO2--N) respectively increased to 300 mg·L-1 and 396 mg·L-1, and the TIN removal rates of the three groups of reactors were respectively 78.96%, 84.92%, and 84.66%. Microbial community structure analysis showed that the relative abundances of ANAMMOX bacteria in the R2 and R3 reactor were respectively 6.85% and 6.06%, two to four times that in the R1 reactor. The predominant ANAMMOX bacteria in the sludge was Candidatus Jettenia, whose relative abundances in the three groups of reactors were respectively 1.62%, 5.74%, and 5.21%. The results show that ANAMMOX biofilm-granular sludge complex systems constructed by adding carriers can considerably shorten the time for recovering ANAMMOX sludge bacterial activity after long-term room temperature storage without substrate. The carriers effectively promoted the relative abundances of ANAMMOX bacteria in the reactors, whereas the promoting effect of comet fiber carrier was slightly more significant than that of the K3 carrier.

Supercooled Sugar Alcohols Stabilized by Alkali Hydroxides for Long-Term Room-Temperature Phase Change Solar-Thermal Energy Storage

Supercooled Sugar Alcohols Stabilized by Alkali Hydroxides for Long-Term Room-Temperature Phase Change Solar-Thermal Energy Storage

Encapsulated Bdellovibrio Powder as a Potential Bio-Disinfectant against Whiteleg Shrimp-Pathogenic Vibrios.

Liquid preparations of bdellovibrios are currently commercialized as water quality improvers to control bacterial pathogens in whiteleg shrimp Penaeus vannamei. However, the efficacy of these liquid preparations is significantly impaired due to a dramatic loss of viable cells during long-term room temperature storage. Thus, new formulations of bdellovibrios are greatly needed for high-stablility room-temperature storage. In the present study, the encapsulated powder of Bdellovibrio sp. strain F16 was prepared using spray drying with 20 g L−1 gelatin as the coating material under a spray flow of 750 L h−1, a feed rate of 12 mL min−1, and an air inlet temperature of 140 °C. It was found to have a cell density of 5.4 × 107 PFU g−1 and to have spherical microparticles with a wrinkled surface and a diameter of 3 μm to 12 μm. In addition, the encapsulated Bdellovibrio powder presented good storage stability with its cell density still remaining at 3.5 × 107 PFU g−1 after 120 days of room-temperature storage; it was safe for freshwater-farmed whiteleg shrimp with an LD50 over 1200 mg L−1, and it exhibited significant antibacterial and protective effects at 0.8 mg L−1 against shrimp-pathogenic vibrios. To our knowledge, this is the first report on a promising Bdellovibrio powder against shrimp vibrios with high stable room-temperature storage.

Long-Term Room Temperature Storage of Dry Ribonucleic Acid for Use in RNA-Seq Analysis.

RNA is an essential biological material for research in genomics and translational medicine. As such, its storage for biobanking is an important field of study. Traditionally, long-term storage in the cold (generally freezers or liquid nitrogen) is used to maintain high-quality (in terms of quantity and integrity) RNA. Room temperature (RT) preservation provides an alternative to the cold, which is plagued by serious problems (mainly cost and safety), for RNA long-term storage. In this study, we evaluated the performance of several RT storage procedures, including the RNAshell® from Imagene, where the RNA is dried and kept protected from the atmosphere, and the vacuum drying of RNA with additives such as the Imagene stabilization solution and a home-made trehalose solution. This evaluation was performed through accelerated (equivalent to 10 years for RNAshell) aging and real-time studies (4 years). To check RNA quality and integrity, we used RNA integrity number values and RNA-seq. Our study shows that isolation from atmosphere offers a superior protective effect for RNA storage compared with vacuum drying alone, and demonstrates that RNAshell permits satisfactory RNA quality for long-term RT storage. Thus, the RNA quality could meet the demand of downstream applications such as RNA-seq.

Development of a Rapidly Dissolvable Oral Pediatric Formulation for Mefloquine Using Liposomes.

Mefloquine (Mef), a poorly soluble and highly bitter drug, has been used for malaria prophylaxis and treatment. The dosage form for Mef is mostly available as adult tablets, and thus children under the age of 5 suffer from poor medication adherence. We have developed a stable, rapidly dissolvable, and palatable pediatric formulation for Mef using liposomes composed of 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) and cholesterol with a mean diameter of ∼110 nm. Mef was actively loaded into the liposomes via an ammonium sulfate gradient using the solvent-assisted loading technology (SALT) developed in our lab. Complete loading of Mef inside the liposomal core was achieved at a high drug-to-lipid ratio (D/L) of 0.1-0.2 (w/w), and the final drug content in the formulation was ∼8 mg/mL, well above the solubility of Mef (<0.6 mg/mL in simulated fluids). The strong bitterness of Mef was masked by the liposomal encapsulation as measured by an electronic tongue. Incubating the Mef-liposomes (Mef-Lipo) in the simulated gastric fluid (pH 1.2) and the simulated intestinal fluid containing 3 mM sodium taurocholate (pH 6.8) induced changes in liposome size and the polydispersity, resulting in drug release (∼40% in 2 h). However, no drug release from the Mef-Lipo was measured in the bile salt-free intestinal fluid or simulated saliva (0% in 3 h). These data suggest that drug release from the Mef-Lipo was mediated by a low pH and the presence of a surfactant. Pancreatic lipase did not degrade DSPC in the Mef-Lipo after 8 h of incubation nor induce Mef release from the liposomes, indicating that lipid digestion played a minor role for drug release from the Mef-Lipo. In order to improve long-term room temperature storage, the Mef-Lipo was lyophilized to obtain a solid formulation, which was completely dissolvable in water in 10 s and displayed similar in vitro profiles of release as the liquid form. The lyophilized Mef-Lipo was stable at room temperature for >3 months. In mice, orally delivered liquid and lyophilized Mef-Lipo displayed comparable absorption with bioavailability (BA) of 81-86%, while the absorption of the standard Mef suspension was significantly lower with BA of 70% and 20% decreased maximal plasma concentration and area under the curve. Our data suggest that the Mef-Lipo was a stable, palatable, and bioavailable formulation that might be suitable for pediatric use.

Accelerated precipitation and growth of phases in an Al-Zn-Mg-Cu alloy processed by surface abrasion

The surface microstructure and its evolution during long-term room-temperature storage were studied using transmission electron microscopy for an Al-Zn-Mg-Cu alloy processed by surface abrasion with grinding paper. An altered surface layer (ASL) with thickness of 0.4–0.8 μm was present on the alloy after abrasion. Ultrafine subgrains with width of about 50–120 nm and a high density of dislocations were observed in the ASL. The pre-existing aging-induced η′ and η precipitates dissolved during surface abrasion. During room-temperature aging, relatively pure Zn, Al2Cu and AlCu phases were observed to precipitate at the extreme surface and subgrain boundaries in the ASL. These phases are very unusual in that they are typically not formed in Al-Zn-Mg-Cu alloys. Mg was not found in these particles, as it remained dissolved in the solid solution of the ASL. Al2Cu and AlCu phases also precipitated at the grain boundaries in the underlying substrate right below the ASL, as far as 6 μm in depth from the extreme surface. Considerable growth and coarsening of these phases occurred during natural aging over a period of 42 months. The enhanced diffusion accelerated by vacancies, dislocations, and subgrain/grain boundaries was considered to be mainly responsible for the accelerated precipitation and growth of these atypical phases.

Tin whisker mitigation by means of a post-electroplating electrochemical oxidation treatment

There are very few studies that have investigated directly the effect of an oxide film on tin whisker growth, since the ‘cracked oxide theory’ was proposed by Tu in 1994 [K.-N. Tu: Phys. Rev., 1994, 49, (3), 2030–2034]. The current study has investigated the effect of an electrochemically produced oxide on tin whisker growth, for both Sn–Cu electrodeposits on Cu and pure Sn electrodeposits on brass. X-ray photoelectron spectroscopy (XPS) has been used to investigate the effect of the applied electrochemical oxidation potential on the oxide film thickness. Focused ion beam has been used to prepare cross sections from electrodeposited samples to investigate the influence of the electrochemically formed oxide film on deposit microstructure during long-term room temperature storage. The XPS studies show that the thickness of electrochemically formed oxide film is directly influenced by the applied potential and the total charge passed. Whisker growth studies show that the electrochemical oxidation treatment mitigates whisker growth for both Sn–Cu electrodeposits on Cu and pure Sn electrodeposits on brass. For Sn electrodeposits on brass, the electrochemically formed oxide greatly reduces both the formation of zinc oxide at the surface and the formation of intermetallic compounds, which results in the mitigation of tin whisker growth. For Sn–Cu electrodeposits on Cu, the electrochemically formed oxide has no apparent effect on intermetallic compound formation and acts simply as a physical barrier to hinder tin whisker growth.

Long-Term Blood Alcohol Stability in Forensic Antemortem Whole Blood Samples.

The effect of long-term room temperature storage on the stability of ethanol in whole blood specimens was investigated. One hundred and seventeen preserved whole blood case samples (110 of 117 with two tubes of blood in each case) were used for this study. One tube from each case was initially tested for blood alcohol concentration (BAC) for criminal driving under the influence proceedings. Cases positive for ethanol ranged in BAC from 0.023 to 0.281 g/dL. The second tube, if present, remained sealed. All blood samples were then stored at room temperature. After 5.4-10.3 years, the opened tubes were reanalyzed for BAC by the same laboratory that performed the initial testing using the same method and same instrumentation. After the same storage period, the unopened tubes were sent to a different laboratory, using a different method and different instrumentation, and reanalyzed for BAC after a total of 5.6-10.5 years of room temperature storage. Seven samples initially negative for alcohol remained negative. All samples initially positive for ethanol demonstrated a decrease in BAC over time with a statistically significant difference in loss observed based on blood sample volume and whether or not the tube had been previously opened. The decrease in BAC ranged from 0.005 to 0.234 g/dL. Tubes that were not previously opened and were more than half full demonstrated better BAC stability with 89% of these tubes demonstrating a loss of BAC between 0.01 and 0.05 g/dL.

An efficient method for long-term room temperature storage of RNA

RNA is a tool used in many fields, from molecular and cellular biology to medicine and nanotechnology. For most of these uses, the integrity of RNA is required and must be maintained during storage. Even though freezing is currently the storage method of choice, the increasing number of samples to be stored and the costly use of a cold chain have highlighted the need for room temperature preservation methods. Here, we report a new room temperature technology that consists in drying RNA samples in the presence of a stabilizer in stainless steel minicapsules. These air- and water-tight capsules isolate RNA from the atmosphere and maintain an anhydrous and anoxic environment. Through the evaluation of RNA integrity over time at room temperature or 90 °C, we identified atmospheric humidity as a major deleterious factor. The degradation rate dependence in temperature fitted an Arrhenius model, with an activation energy of 28.5 kcal/mol and an extrapolated room temperature degradation rate of 3.2 10(-13)/nt/s (95% confidence interval: 2.3-4.2/nt/s). In these conditions, it is expected that an RNA molecule will be subjected to 0.7-1.3 cut every 1000 nucleotides per century. In addition, we showed that stored RNA is compatible for further analyses, such as reverse transcription-quantitative PCR. No significant change in the Cq values was observed over a simulated period of several decades. At last, our data are consistent with a sequence-independent degradation rate of RNA in the solid state.

Lyophilized brain tumor specimens can be used for histologic, nucleic acid, and protein analyses after 1 year of room temperature storage

Frozen tissue, a gold standard biospecimen, can yield well preserved nucleic acids and proteins after over a decade but is vulnerable to thawing and has substantial fiscal, spatial, and environmental costs. A long-term room temperature biospecimen storage alternative that preserves broad analytical utility can potentially empower tissue-based research. As there is scant data on the analytical utility of lyophilized brain tumor biospecimens, we evaluated lyophilized (freeze-dried) samples stored for 1 year at room temperature. Lyophilized tumor tissue processed into paraffin sections produced good histology. Yields of extracted DNA, RNA, and protein approximated those of frozen tissue. After 1 year, lyophilized samples yielded high molecular weight DNA that permitted copy number variation analysis, IDH 1 mutation detection, and MGMT promoter methylation PCR. A 27 % decrease in RIN scores over the 1 year suggests that RNA degradation was inhibited though incompletely. Nevertheless, RT-PCR studies on lyophilized tissue performed similarly to frozen tissue. In contrast to FFPE tissues where protein bands were absent or shifted to a lower molecular weight, lyophilized samples showed similar protein bands as frozen tissue on SDS-PAGE analysis. Lyophilized tissue performed similarly to frozen tissue for Western blots and enzyme activity assays. Immunohistochemistry of lyophilized tissue that were processed into FFPE blocks often required longer incubation times for staining than standard FFPE samples but generally provided robust antigen detection. This preliminary study suggests that lyophilization has promise for long-term room temperature storage while permitting varied tests; however, further work is required to better stabilize nucleic acids particularly RNA.

Protein Extraction of the Long-Term Room Temperature Storage Wheat Straw

Study on extract protein from long-term room temperature storage of wheat straw,utilize L9(34) Orthogonal experiment on the basis of single factor test.Study the impact of extraction time,extraction temperature and solid-liquid ratio on protein extraction yield of wheat straw.Result show factors affect wheat straw protein extraction rate in the order of extraction time&gt;extraction temperature&gt;liquid ratio&gt;blank test,the optimal conditions is 50°C, the solid-liquid ratio 1:20 extract for 12 hours.Measured extraction yield is 21.761%.

Interdependent effect of chemical composition and thermal history on artificial aging of AA6061

In this study, the interdependent effect of chemical composition and thermal history on artificial aging was investigated for the aluminum alloy AA6061. Based on thermodynamic calculations, including Al, Fe, Cr, Zn, Ti, Mg, Si and Cu, model alloys exhibiting a maximum variation of the reachable solute super-saturation of elements relevant for precipitation hardening within the compositional limits of AA6061 were produced. The artificial aging behavior of these alloys at 175°C was studied by tensile testing for two thermal histories, including very short- and long-term room temperature storage after quenching. Precipitation during artificial aging was investigated by an analysis of yield strength data. As generally expected, precipitation kinetics was found to depend strongly on the solute super-saturation in the case of very short room temperature storage. For artificial aging after long-term room temperature storage the kinetics showed almost no dependence on the chemical composition. This seems to be an exception from simple precipitation kinetics and can be explained based on the complex role of quenched-in vacancies in artificial aging of AA6061.

Changes in germinability, lipid peroxidation, and antioxidant enzyme activities in pear stock (Pyrus betulaefolia Bge.) seeds during room- and low-temperature storage

The aim of this study was to determine if loss of germinability in Pyrus betulaefolia seeds stored at 4°C and at room temperature is associated with a loss of membrane lipid peroxidation or changes in antioxidant enzyme activities. The results indicated that germination percentage clearly decreased when seeds were stored at room temperature rather than at 4°C from 6 to 12 months. Room-temperature storage of the pear stock seed for 12 months decreased germination to 15.52%, but germination percentage was not changed when seed was stored at 4°C for 12 months. MDA, a marker for membrane lipid peroxidation, increased significantly under room-temperature storage conditions. Antioxidant enzyme (SOD, POD, and CAT) activities were a good indicator of germination percentage in pear stock seeds. Antioxidant enzyme activities of pear stock seeds at 4°C were higher than antioxidant enzyme activities in seeds stored at room temperature from 6 to 12 months. Antioxidant enzyme activities of the pear stock seed decreased markedly under conditions of room-temperature storage from 6 to 12 months. The results of this study showed that long-term room-temperature storage was detrimental for maintaining the vigor of P. betulaefolia seeds. The mechanisms responsible for this outcome are a higher level of membrane lipid peroxidation and a lower level of activity of antioxidant enzymes.

Comparative Study of Virgin Olive Oil Behavior under Rancimat Accelerated Oxidation Conditions and Long-Term Room Temperature Storage

Oxidative stability should be one of the most important quality markers of edible oils; nevertheless, it is not recognized as a legal parameter. The results reported in this study highlight the differences in the olive oil oxidation process under Rancimat accelerated conditions with respect to long-term storage at room temperature and clearly show the lack of correlation between shelf life and the Rancimat induction period. A better correlation, although not yet satisfactory, was found when the same oxidation end-point was used in both assays. The parameter K 270, a marker of secondary oxidation products, was the first index to reach the established upper legal limit under Rancimat conditions, whereas at 25 degrees C it was an index of primary oxidation products ( K 232). Furthermore, the ratio of oxidation rate at Rancimat conditions to oxidation rate at 25 degrees C was more than double for secondary oxidation products compared with primary ones. Notable differences were also observed in degradation rates of the different unsaturated fatty acids and in rates of formation of polar oxidation compounds. Moreover, under the Rancimat conditions antioxidants such as o-diphenols and alpha-tocopherol rapidly depleted, and when they had practically disappeared, there was a sharp increase in oxidation indices, such as peroxide value, and in oxidation products. At 25 degrees C, on the other hand, the depletion was much lower.

Ultrasound-accelerated Tissue Fixation/Processing Achieves Superior Morphology and Macromolecule Integrity with Storage Stability

We demonstrate that high-frequency and high-intensity ultrasound (US) can be applied to both tissue fixation and tissue processing to complete the conventional overnight formalin-fixation and paraffin-embedding (FFPE) procedures within 1 hr. US-facilitated FFPE retains superior tissue morphology and long-term room temperature storage stability than conventional FFPE. There is less alteration of protein antigenicity after US-FFPE preservation so that rapid immunohistochemical reactions occur with higher sensitivity and intensity, reducing the need for antigen retrieval pretreatment. US-FFPE tissues present storage stability so that room temperature storage up to 7 years does not significantly affect tissue morphology, protein antigenic properties, RNA distribution, localization, and quantitation. In addition, during fixation, tissue displays physical changes that can be monitored and reflected as changes in transmission US signals. As far as we know, this is the first effort to monitor tissue physical changes during fixation. Further study of this phenomenon may provide a method to control and to monitor the level of fixation for quality controls. The mechanism of less alteration of protein antigenicity by US-FFPE was discussed.

Effect of long-term room-temperature storage on the structure and properties of glassy melt-spun Mg-Al-Ca alloys

The effects of 48 months storage at room temperature on the structure and properties of glassy meltspun Mg-Al-Ca alloys has been determined. The results show that while Knoop hardness does not differ significantly from values obtained shortly after melt spinning, x-ray diffraction (XRD) shows considerably stronger signals from αMg present in the glassy matrix, detected only for the most dilute glass forming composition some months after melt spinning. High-resolution electron microscopy (HREM) studies show the presence of nanocrystallites in the glassy matrix with interplanar spacings matching αMg, and energy-dispersive spectroscopy (EDS) indicates the presence of Al and Ca within these nanocrystallites. Differential scanning calorimetry (DSC) studies at 20, 40, and 80 K/min show evidence of two-stage crystallization with the first stage starting at ∼120 deg with a peak at ∼150 °C and the second stage peaking at ∼250 °C. The significance of these results is discussed.

Mixed fluorocarbon/hydrocarbon molecular “dowels” allow improved control over concentrated fluorocarbon emulsion particle sizes and stability

Highly concentrated (90% w/v, 47% v/v) fluorocarbon/egg yolk phospholipids (EYP) emulsions for oxygen transport and delivery systems (blood substitutes) are presently under development. Primary objectives of the research are to optimally adapt the emulsions characteristics (particle size, size distribution, viscosity, in vivo recognition, etc…) to the specific requirements of each of the targeted applications and to increase the stability of the emulsions for long-term room temperature storage and transportation. A new approach to emulsion stabilization utilizes linear mixed fluorocarbon- hydrocarbon amphiphiles to improve the cohesion between the surfactant film and the fluorocarbon phase [J.G. Riess and M. Postel, Biomat., Art. Cells, Immob. Biotech., (in press)]. The role of the surfactant in lowering the interfacial tension is divided into two complementary contributions, one involving the classical hydrophilic/lipophilic EYP, the other a lipophilic/ fluorophilic surfactant, i.e. the mixed hydrocarbon/fluorocarbon compound. This compound plays the role of a molecular dowel between the fluorocarbon phase and the lipidic fatty acid chains of the EYP membrane. We report here the preparation of stable concentrated fluorocarbon emulsions stabilized by molecular dowels. With one mole of the dowel molecules (C 8H 17CHCHC 8F 17) per mole of EYP, no detectable increase in average particle size has been observed after 9 months of storage at 40 °C, after an initial stabilization period of ca. 20 days. The size of the droplets in the emulsions is directly related to the amount of phospholipids and dowels. For a range of EYP concentration from 0.1 to 4%, it is possible to prepare both very fine emulsions (ca. 0.13 μm post-sterilization) using 4% EYP, as well as much coarser, but nevertheless narrowly distributed and sterilizable emulsions of ca. 2.5 μm in diameter. In that range of concentrations, we have observed a linear variation of droplet diameters of fluorocarbon emulsions stabilized by molecular dowels as a function of the EYP concentration. We will discuss the mechanism of stabilization brought by the molecular dowels in comparison with other additives, which usually operate by slowing down the molecular diffusion process (Ostwald rippening), which is admitted to be the major cause of degradation of fluorocarbon emulsions during ageing.