Lipid Layer Research Articles

Diamond Bur Microblepharoexfoliation Combined with Intense Pulse Light and Meibomian Gland Expression for Evaporative Dry Eye: A Short-term Controlled Clinical Trial.

To assess the efficacy and safety of the combination of microblepharoexfoliation (MBE), intense pulse light (IPL) and meibomian gland expression (MGX) for treatment of meibomian gland dysfunction (MGD). This was a prospective, parallel-control trial conducted from April 2022 to January 2023. Participants were assigned to receive either three sessions of MBE-IPL-MGX treatment and home-based therapy (treatment group) or home-based therapy alone (control group). Outcome measures were assessed at baseline and after 2-month follow-up. Seventy eyes of 70 patients were enrolled. MBE-IPL-MGX treatment achieved better improvements than home-based therapy in ocular surface disease index (OSDI) and symptom assessment in dry eye (SANDE) scores, noninvasive tear film break-up time (NIBUT), lipid layer grade (LLG), loss area meibomian gland (LAMG) and meibomian gland yielding secretion score (MGYSS). The mean differences between the two groups were as follows: OSDI (- 11.23 ± 4.68 points, P < 0.001), SANDE (- 24.63 ± 13.41 points, P < 0.001), NIBUT (1.3 ± 1.57s, P = 0.033), LLG (0.4 ± 0.04 points, P = 0.003), LAMG (- 2.85 ± 1.69%, P = 0.023) and MGYSS (7.5 ± 2.32 points, P < 0.001). In addition, the increment (Δ) of MGYSS after MBE-IPL-MGX treatment was significantly higher in MGD grades 2 and 3 (all P < 0.001). MBE-IPL-MGX treatment is an effective and well-tolerated procedure that improves dry eye symptoms and signs as well as meibomian gland secretions in patients with MGD. In addition, this treatment is recommended for MGD grades 2 and 3.

An antibiotic-free platform for eliminating persistent Helicobacter pylori infection without disrupting gut microbiota

Helicobacter pylori (H. pylori) infection remains the leading cause of gastric adenocarcinoma, and its eradication primarily relies on the prolonged and intensive use of two antibiotics. However, antibiotic resistance has become a compelling health issue, leading to H. pylori eradication treatment failure worldwide. Additionally, the powerlessness of antibiotics against biofilms, as well as intracellular H. pylori and the long-term damage of antibiotics to the intestinal microbiota, have also created an urgent demand for antibiotic-free approaches. Herein, we describe an antibiotic-free, multifunctional copper-organic framework (HKUST-1) platform encased in a lipid layer comprising phosphatidic acid (PA), rhamnolipid (RHL), and cholesterol (CHOL), enveloped in chitosan (CS), and loaded in an ascorbyl palmitate (AP) hydrogel: AP@CS@Lip@HKUST-1. This platform targets inflammatory sites where H. pylori aggregates through electrostatic attraction. Then, hydrolysis by matrix metalloproteinases (MMPs) releases CS-encased nanoparticles, disrupting bacterial urease activity and membrane integrity. Additionally, RHL disperses biofilms, while PA promotes lysosomal acidification and activates host autophagy, enabling clearance of intracellular H. pylori. Furthermore, AP@CS@Lip@HKUST-1 alleviates inflammation and enhances mucosal repair through delayed Cu2+ release while preserving the intestinal microbiota. Collectively, this platform presents an advanced therapeutic strategy for eradicating persistent H. pylori infection without inducing drug resistance.

Chemical analysis of meibum composition of type 2 diabetes mellitus

The meibomian glands, by producing a lipid-rich secretion (meibum), are involved in the formation of the lipid layer of the tear film, preventing its evaporation and ensuring the maintenance of ocular surface homeostasis. Meibomian gland dysfunction is a common disease. Numerous clinical studies have pointed to involvement of the meibomian glands in a number of systemic diseases, including diabetes mellitus. Hyperglycemia provokes the development of oxidative stress and metabolic disorders, leading to changes in the anatomical and functional state of the breast, which affects the qualitative and quantitative composition of the secretion. Instrumental methods of meibomian glands assessment reflect their morphofunctional state, and chemo-analytical study of the meibum can serve as a reflection of anatomical and physiological changes of the glands. Proteomic technologies are promising methods for studying the composition of the meibomian glands secretion, allowing us to determine the patterns of changes in the chemical composition of the meibum in patients with diabetes mellitus to detect early signs of the disease and prevent the development of complications.

Fetal growth restriction exhibits various mTOR signaling in different regions of mouse placentas with altered lipid metabolism

Fetal growth restriction (FGR) is a common complication of pregnancy and can have significant impact on obstetric and neonatal outcomes. Increasing evidence has shown that the inhibited mechanistic target of rapamycin (mTOR) signaling in placenta is associated with FGR. However, interpretation of existing research is limited due to inconsistent methodologies and varying understanding of the mechanism by which mTOR activity contributes to FGR. Hereby, we have demonstrated that different anatomic regions of human and mouse placentas exhibited different levels of mTOR activity in normal compared to FGR pregnancies. When using the rapamycin-induced FGR mouse model, we found that placentas of FGR pregnancies exhibited abnormal morphological changes and reduced mTOR activity in the decidual-junctional layer. Using transcriptomics and lipidomics, we revealed that lipid and energy metabolism was significantly disrupted in the placentas of FGR mice. Finally, we demonstrated that maternal physical exercise during gestation in our FGR mouse model was associated with increased fetal and placental weight as well as increased placental mTOR activity and lipid metabolism. Collectively, our data indicate that the inhibited placental mTOR signaling contributes to FGR with altered lipid metabolism in mouse placentas, and maternal exercise could be an effective method to reduce the occurrence of FGR or alleviate the adverse outcomes associated with FGR.Graphical Human and mouse placentas have different mTOR signaling activities in different anatomic regions in normal and FGR pregnancies.Pregnant mice with FGR induced by rapamycin show smaller placentas, decreased mTOR activity in DJ layer of placenta and altered lipid metabolism.Maternal exercise partially alleviates the abnormal outcomes of FGR model.

Ocular surface and meibomian gland evaluation in euthyroid Graves’ ophthalmopathy

PurposeEuthyroid Graves’ ophthalmology (EGO) refers to the subgroup of thyroid eye disease patients with distinct clinical presentations. This study evaluated the ocular surface and meibomian gland changes in EGO patients.MethodsA cross-sectional study was conducted at The Chinese University of Hong Kong including 34 EGO patients and 34 age-and sex- matched healthy controls. Outcome measures include anterior segment examination, keratographic and meibographic imaging.ResultsBetween 34 EGO patients and 34 age and sex-matched healthy controls, EGO was associated with a higher ocular surface disease index (P < 0.01), higher severity of meibomian gland dropout (upper: P < 0.001, lower: P < 0.00001) and higher percentage of partial blinking (P = 0.0036). The worse affected eyes of the EGO patients were associated with corneal staining (P = 0.0019), eyelid telangiectasia (P = 0.0009), eyelid thickening (P = 0.0013), eyelid irregularity (P = 0.0054), meibomian gland plugging (P < 0.00001), expressibility (P < 0.00001), and meibum quality (P < 0.00001). When the two eyes of the same EGO patient were compared, the degree of meibomian gland dropout was higher among the worse affected eyes (upper: P < 0.00001, and lower: P < 0.00001). Tear meniscus height, lipid layer thickness, and noninvasive break-up time were comparable between the two eyes of EGO patients and also between EGO patients and healthy controls. TMH was positively correlated with the degree of exophthalmos (r = 0.383, P < 0.05).ConclusionEGO patients have more ocular surface complications and meibomian gland dropouts than healthy controls. Almost 60% of them had dry eye symptoms, but aqueous deficiency was not apparent. Further studies are warranted to clarify the mechanism of dry eye in EGO.(249 words).

Silencing NlFAR7 destroyed the pore canals and related structures of the brown planthopper.

Fatty acyl-CoA reductase (FAR) is one of the key enzymes, which catalyses the conversion of fatty acyl-CoA to the corresponding alcohols. Among the FAR family members in the brown planthopper (Nilaparvata lugens), NlFAR7 plays a pivotal role in both the synthesis of cuticular hydrocarbons and the waterproofing of the cuticle. However, the precise mechanism by which NlFAR7 influences the formation of the cuticle structure in N. lugens remains unclear. Therefore, this paper aims to investigate the impact of NlFAR7 through RNA interference, transmission electron microscope, focused ion beam scanning electron microscopy (FIB-SEM) and lipidomics analysis. FIB-SEM is employed to reconstruct the three-dimensional (3D) architecture of the pore canals and related cuticle structures in N. lugens subjected to dsNlFAR7 and dsGFP treatments, enabling a comprehensive assessment of changes in the cuticle structures. The results reveal a reduction in the thickness of the cuticle and disruptions in the spiral structure of pore canals, accompanied by widened base and middle diameters. Furthermore, the lipidomics comparison analysis between dsNlFAR7- and dsGFP-treated N. lugens demonstrated that there were 25 metabolites involved in cuticular lipid layer synthesis, including 7 triacylglycerols (TGs), 5 phosphatidylcholines (PCs), 3 phosphatidylethanolamines (PEs) and 2 diacylglycerols (DGs) decreased, and 4 triacylglycerols (TGs) and 4 PEs increased. In conclusion, silencing NlFAR7 disrupts the synthesis of overall lipids and destroys the cuticular pore canals and related structures, thereby disrupting the secretion of cuticular lipids, thus affecting the cuticular waterproofing of N. lugens. These findings give significant attention with reference to further biochemical researches on the substrate specificity of FAR protein, and the molecular regulation mechanisms during N. lugens life cycle.

The Short-term Effects of Artificial Tears on the Tear Film Assessed by a Novel High-Resolution Tear Film Imager: A Pilot Study.

The purpose of this study was to investigate the effects of artificial tears (AT) on the sublayers of the tear film assessed by a novel tear film imaging (TFI) device. The mucoaqueous layer thickness (MALT) and lipid layer thickness (LLT) of 198 images from 11 healthy participants, 9 of whom had meibomian gland disease, were prospectively measured before and after exposure to 3 different AT preparations (Refresh Plus; Retaine [RTA]; Systane Complete PF [SYS]), using a novel nanometer resolution TFI device (AdOM, Israel). Participants were assessed at baseline and at 1, 5, 10, 30, and 60 minutes after instilling 1 drop of AT during 3 sessions on separate days. Repeated-measures analysis of variances were used for comparisons with P < 0.05 considered significant. For all ATs, the mean MALT was greatest 1 minute after drop instillation, with an increase of 67%, 55%, and 11% above the baseline for SYS, Refresh Plus, and RTA, respectively. The SYS formulation demonstrated the highest percentage increases in mean MALT and LLT at most postdrop time points. The MALT differences were significantly higher in the SYS than in the RTA ( P = 0.014). After 60 minutes, no AT group demonstrated statistically significant changes in MALT or LLT compared with baseline. We report, for the first time, the effects of AT on MALT and LLT using a high-resolution TFI. A substantial acute mean MALT increase occurs 1 minute after AT instillation with all agents tested, but there were clear differences in response and durability, suggesting the benefits of choosing specific AT according to the needs of each patient.

Comparison of non-pharmaceutical treatments for evaporative dry eye: a randomised controlled study protocol

IntroductionThe lipid layer of the tear film is critical to maintaining the integrity of the tear film and absence in the tear film lipid layer (TFLL) is one of the...

Ocular surface changes following computer use in post-LASIK patients.

To assess the impact of computer use on the ocular surface of individuals after laser insitu keratomileusis (LASIK). The dry eye symptoms and ocular surface of 18 post-LASIK young individuals and 18 controls were evaluated before and after performing a 30-min task on a computer without (Visit 1) and with (Visit 2) initial instillation of artificial tears. Symptoms were assessed using the Ocular Surface Disease Index (OSDI), Symptom Assessment in Dry Eye questionnaire version two (SANDE II) and Computer Vision Syndrome Questionnaire (CVS-Q). The ocular surface was assessed by measuring corneal higher order aberrations, tear meniscus height (TMH), conjunctival redness, blink rate and incomplete blinking, lipid layer thickness (LLT) and non-invasive keratograph break-up time (NIKBUT). SANDE II scores were >0 after the computer task in both groups (p ≤ 0.01). SANDE II and CVS-Q scores did not differ between LASIK and controls (p ≥ 0.43). Greater bulbar-temporal conjunctival redness, TMH and LLT and shorter NIKBUT were found after computer use in the LASIK group (p ≤ 0.04), whereas no changes were observed in the controls (p ≥ 0.20). Lower SANDE II and CVS-Q scores were reported at Visit 2 compared with Visit 1 in both groups (p ≤ 0.01). Likewise, no worsening of dry eye signs was observed at Visit 2 (p ≥ 0.11). Ocular symptoms reported during computer use were comparable between the groups. However, a worsening of dry eye signs was mostly observed in post-LASIK individuals. The instillation of artificial tears was effective in preventing the effects of computer use on the ocular surface in post-LASIK patients.

Efficiency of NZ2114 on Superficial Pyoderma Infected with Staphylococcus pseudintermedius.

Staphylococcus pseudintermedius (S. pseudintermedius) is the main pathogen causing pyoderma of canines. With the emergence of drug-resistant bacteria, traditional antibiotic treatments are limited. As a potential antibacterial agent, NZ2114 was effective against S. pseudintermedius, including drug-resistant strains. Its bactericidal efficacy was superior to mupiroxacin, ofloxacin and lincomycin. To facilitate the transcutaneous delivery of NZ2114 for the treatment of superficial pyoderma, chemical permeation enhancers were added since water-soluble NZ2114 does not easily penetrate the skin lipid layer. Two different NZ2114 sprays were prepared by combining 1% Azone + 10% propylene glycol (PG) or 5% N-methylpyrrolidone (NMP) + 10% PG with NZ2114 after screening. The cumulative permeability of NZ2114 sprays were 244.149 and 405.245 μg/cm2 at 24 h with an in vitro percutaneous assay of mice skin, which showed a 244% and 405% increase in skin permeability than NZ2114, respectively. In addition, the efficacy of NZ2114 sprays in reducing skin bacteria colonisation was demonstrated in a mouse model of superficial pyoderma (24 mice, 3 mice/group) induced by S. pseudintermedius, and the 5% NMP + 10% PG + NZ2114 group had the best therapeutic effect compared to the other groups. This preparation did not cause any skin irritation, laying the foundation for the development of an effective and non-toxic topical product.

The Signature of Fluctuations of the Hydrogen Bond Network Formed by Water Molecules in the Interfacial Layer of Anionic Lipids

As the water molecules found at the interface of lipid bilayers exhibit distinct structural and reorientation dynamics compared to water molecules found in bulk, the fluctuations in their hydrogen bond (HB) network are expected to be different from those generated by the bulk water molecules. The research presented here aims to gain an insight into temperature-dependent fluctuations of a HB network of water molecules found in an interfacial layer of multilamellar liposomes (MLVs) composed of anionic 1,2-dimyristoyl-sn-glycero-3-phospho-L-serine (DMPS) lipids. Besides suspending DMPS lipids in phosphate buffer saline (PBS) of different pH values (6.0, 7.4, and 8.0), the changes in HB network fluctuations were altered by the incorporation of a non-polar flavonoid molecule myricetin (MCE) within the hydrocarbon chain region. By performing a multivariate analysis on the water combination band observed in temperature-dependent FTIR spectra, the results of which were further mathematically analyzed, the temperature-dependent fluctuations of interfacial water molecules were captured; the latter were the greatest for DMPS in PBS with a pH value of 7.4 and in general were greater for DMPS multibilayers in the absence of MCE. The presence of MCE made DMPS lipids more separated, allowing deeper penetration of water molecules towards the non-polar region and their restricted motion that resulted in decreased fluctuations. The experimentally observed results were supported by MD simulations of DMPS (+MCE) lipid bilayers.

Analysis on the changes of objective indicators of dry eye after implantable collamer lens (ICL) implantation surgery.

To explore whether implantable collamer lens implantation has any effect on the postoperative objective indicators of dry eye and to determine the severity of its influence on each indicator. This prospective observational trial was performed in the Department of Ophthalmology of West China Hospital and was approved by the Biomedical Ethics Sub-Committee of the West China Hospital of Sichuan University. A total of 89 non-dry eye patients (178 eyes in total) who received ICL implantation surgery at West China Hospital of Sichuan University were enrolled. The noninvasive keratograph tear film breakup time (NIKBUT), noninvasive keratograph tear meniscus height (NIKTMH), score of lipid layer, score of meibomian gland function, and hyperemia index were obtained via the OCULUS Keratograph for all subjects before surgery and at 1week, 1month, and 3months after surgery. The fluorescein tear film breakup time (FBUT), corneal fluorescein staining score (CFS), and Schirmer test I were also measured at the same time. A total of 178 eyes completed the 1-week and 1-month follow-up, and 40 eyes completed the 3-month follow-up. Compared with the preoperative baseline, there was no significant difference in the NIKBUT or the corneal fluorescein staining score at each follow-up time point (P > 0.05, P > 0.05, P > 0.05). The FBUT and Schirmer test I at 1week, 1month, and 3months after surgery were significantly higher than the preoperative baseline (P < 0.01, P < 0.01, P < 0.01). The NIKTMH and the score of lipid layer were significantly lower than the preoperative baseline at 1week, 1month, and 3months after surgery (P < 0.01, P < 0.01, P < 0.05). The score of meibomian gland function and hyperemia index were significantly lower than the preoperative baseline 1week after surgery (P < 0.01). ICL implantation has no adverse effect on the occurrence of postoperative dry eye, but it reduces the basal tear secretion of patients after surgery and has adverse effects on the indices of meibomian gland function in the short term postoperatively.

Uveitis and Dry Eye Disease in Children: A Cross-Sectional Comparative Study

ABSTRACT Purpose This study aims to evaluate the ocular surface characteristics in children diagnosed with uveitis and explore the association between uveitis and dry eye disease (DED). Methods We included 84 children, 42 with uveitis and 42 healthy children. We performed the OSDI questionnaire and several ocular surface tests, including osmolarity, NITBUT, Schirmer test, and vital staining. We used Fisher’s exact test and Mann-Whitney to compare variables and a binomial logistic regression to determine the factors associated with DED. Results The difference in the prevalence of DED between uveitis (54.8%) and healthy (31%) groups was statistically significant (p < 0.05). Most patients with uveitis had mixed DED, and none of the healthy subjects had a severe form of the disease. There were no statistically significant differences in most of the tear film tests. However, all parameters tended to worsen in the uveitis group, and lipid layer thickness was thinner (p < 0.036). The uveitis group exhibited significantly more symptoms (p < 0.05). In the multivariate logistic regression, uveitis was associated with an odds ratio (OR) of 3.0 (95% CI: 1.07–8.42, p < 0.05) for DED. Conclusions Our findings demonstrate a significantly higher prevalence of DED in children with uveitis compared to their healthy counterparts. Furthermore, our analysis indicates that the risk of DED in pediatric patients with uveitis is threefold higher than in healthy children. Therefore, it is crucial for clinicians to vigilantly monitor the development of DED in pediatric patients with uveitis and consider the implementation of preventive treatments.

Self-Assembling Anti-Freezing Lamellar Nanostructures in Subzero Temperatures.

The requirement for cryogenic supramolecular self-assembly of amphiphiles in subzero environments is a challenging topic. Here, the self-assembly of lamellar lyotropic liquid crystals (LLCs) are presented to a subzero temperature of -70 °C. These lamellar nanostructures are assembled from specifically tailored ultra-long-chain surfactant stearyl diethanolamine (SDA) in water/glycerol binary solvent. As the temperature falls below zero, LLCs with a liquid-crystalline Lα phase, a tilted Lβ phase, and a new folded configuration are obtained consecutively. A comprehensive experimental and computational study is performed to uncover the precise microstructure and formation mechanism. Both the ultra-long alkyl chain and head group of SDA play a crucial role in the formation of lamellar nanostructures. SDA head group is prone to forming hydrogen bonds with water, rather than glycerol. Glycerol cannot penetrate the lipid layer, which mixes with water arranging outside of the lipid bilayer, providing an ideal anti-freezing environment for SDA self-assembly. Based on these nanostructures and the ultra-low freezing point of the system, a series of novel cryogenic materials are created with potential applications in extremely cold environments. These findings would contribute to enriching the theory and research methodology of supramolecular self-assembly in extreme conditions and to developing novel anti-freezing materials.

Changes in Ocular Surface Parameter After Intense Pulsed Light Therapy in Ocular Demodicosis: A Case Report

Introduction : Demodex infestation may manifest as blepharitis and dry eye syndrome. Intense Pulsed Light (IPL) therapy is an emerging option for managing ocular demodicosis.&#x0D; Case Illustration : A 77-years-old woman complained of itch and watery eyes since four years ago. Meibomian pouting, telangiectasias, foamy secretions, and sleeves were identified in both eyelids. Right eye examination showed 52% and 42% meibomian dropout in the superior and inferior eyelid, respectively, Schirmer test 6 mm, lipid layer thickness (LLT) 43 nm, tear meniscus height (TMH) 0.36 mm, and non-invasive tear break-up time (NIBUT) 9.6 seconds. Left eye examination showed 65% and 56% meibomian dropout in the superior and inferior eyelid, respectively, Schirmer test 5 mm, LLT 66 nm, TMH 0.16 mm, and NIBUT 5.8 seconds. Demodex mites were identified during eyelash wet mount examination. She underwent four sessions of IPL. At the two-month follow-up, complaints were alleviated. Signs of blepharitis were subsided. Right eye examination showed 36% and 34% meibomian dropout in the superior and inferior eyelid, respectively, Schirmer's test 9 mm, LLT 68 nm, TMH 0.49 mm, and NIBUT 10.7 seconds. Left eye examination showed 25% and 35% meibomian dropout in the superior and inferior eyelid, respectively, Schirmer's test 9 mm, LLT &gt;100 nm, TMH 0.9 mm, and NIBUT 6.2 seconds.&#x0D; Discussion : IPL has a role in managing ocular demodicosis by local inflammation control, meibum liquefaction, and meibomian glands photomodulation. IPL is also thought to directly eradicate Demodex mites.&#x0D; Conclusion : Improvement of ocular surface parameters was observed after IPL therapy in ocular demodicosis.

Repeatable Acoustic Vaporization of Coated Perfluorocarbon Bubbles for Micro-Actuation Inspired by Polypodium aureum.

Polypodium aureum, a fern, possesses a specialized spore-releasing mechanism like a catapult induced by the quick expansion of vaporized bubbles. This study introduces lipid-coated perfluorocarbon droplets to enable repeatable vaporization-condensation cycles, inspired by the repeatable vaporization of Polypodium aureum. Lipid-perfluorocarbon droplets have been considered not to exhibit repeatable oscillations due to bubble collapse of the low surface tension of lipid layers. However, a single lipid-dodecafluoropentane droplet with a diameter of 9.17 µm shows expansion-contraction oscillations over 4000 cycles by changing lipid composition and applying a low-power 1.7 MHz ultrasound to induce the partial vaporization of the droplets. The optimal combinations of shell composition, droplet fabrication, and acoustic conditions can minimize the damage on shell structure and promote a quick recovery of damaged shell layers. The highly expanding oscillatory microbubbles provide a new direction for fuel-free micro- or nanobots, as well as biomedical applications of contrast agents and drug delivery.

An Esterase-Responsive SLC7A11 shRNA Delivery System Induced Ferroptosis and Suppressed Hepatocellular Carcinoma Progression.

Ferroptosis has garnered attention as a potential approach to fight against cancer, which is characterized by the iron-driven buildup of lipid peroxidation. However, the robust defense mechanisms against intracellular ferroptosis pose significant challenges to its effective induction. In this paper, an effective gene delivery vehicle was developed to transport solute carrier family 7 member 11 (SLC7A11) shRNA (shSLC7A11), which downregulates the expression of the channel protein SLC7A11 and glutathione peroxidase 4 (GPX4), evoking a surge in reactive oxygen species production, iron accumulation, and lipid peroxidation in hepatocellular carcinoma (HCC) cells, and subsequently leading to ferroptosis. This delivery system is composed of an HCC-targeting lipid layer and esterase-responsive cationic polymer, a poly{N-[2-(acryloyloxy)ethyl]-N-[p-acetyloxyphenyl]-N} (PQDEA) condensed shSLC7A11 core (G-LPQDEA/shSLC7A11). After intravenous (i.v.) injection, G-LPQDEA/shSLC7A11 quickly accumulated in the tumor, retarding its growth by 77% and improving survival by two times. This study is the first to construct a gene delivery system, G-LPQDEA/shSLC7A11, that effectively inhibits HCC progression by downregulating SLC7A11 expression. This underscores its therapeutic potential as a safe and valuable candidate for clinical treatment.

Evaluation of tear film in patients with AIDS without opportunistic ocular infections in the era of COVID-19: A case-control study.

The assessment of tear film and ocular surface conditions in patients with acquired immunodeficiency syndrome (AIDS) has been poorly studied thus far. We aim to assess tear film parameters, ocular surface characteristics, and dry eye disease (DED) symptoms of patients with AIDS who did not undergo highly active antiretroviral treatment (HAART). This case-control study included 154 age-, sex-, and ethnicity-matched healthy controls and patients with AIDS. All participants underwent comprehensive ocular surface assessment and subjective DED symptomology evaluation. Data were collected between March 2022 and July 2022. HAART-naïve patients with AIDS had a shorter noninvasive tear film breakup time (median 3.76 vs. 8.54 s), thinner tear film lipid layer thickness (median 73.00 vs. 91.00 nm), and lower Schirmer I test values (median 5.00 mm/5 min vs. 12.00 mm/5 min) (all P < 0.001). Moreover, higher corneal fluorescein staining scores (median 1.00 vs. 0.00) and higher upper, lower, and total meibomian gland grades were observed in AIDS patients (all P < 0.05). Negative correlations between the blood viral load and the Ocular Surface Disease Index score ( r = -3.50, P = 0.027) and the Schirmer I test score ( r = -0.374, P = 0.017) were detected in patients with AIDS. Altered tear film status was observed in individuals with HAART-naïve AIDS, even when there were no other ocular symptoms present. Therefore, patients with AIDS should be encouraged to undergo comprehensive ocular surface examinations to detect any subclinical tear film alterations occurring.

Real-time tracking of the adsorption of bovine serum albumin on lipid layer and its effect on lipolysis by optical interferometry

The model proteins bovine serum albumin (BSA) and lipid layer were used to study the effect of proteins on lipolysis. A lipid layer with an interference effect was constructed by loading the triolein into the silica colloidal crystal (SCC) film. The ordered porous layer interferometry (OPLI) system was used to track the changes in lipid layer mass caused by lipase hydrolysis to achieve real-time lipolysis detection. The real-time tracking of the adsorption of BSA on the lipid layer by converting the migration of interference fringes caused by the change of the lipid layer into the optical thickness change (ΔOT). The effect of BSA on the early and late stages of lipolysis was studied, and lipases containing 5 mg/mL BSA degraded the lipid layer 3.4 times faster than lipases containing 0.1 mg/mL BSA in the later stages. This study deepens the understanding of protein-lipid interactions in complex digestive environments.

Implicit model to capture electrostatic features of membrane environment.

Membrane protein structure prediction and design are challenging due to the complexity of capturing the interactions in the lipid layer, such as those arising from electrostatics. Accurately capturing electrostatic energies in the low-dielectric membrane often requires expensive Poisson-Boltzmann calculations that are not scalable for membrane protein structure prediction and design. In this work, we have developed a fast-to-compute implicit energy function that considers the realistic characteristics of different lipid bilayers, making design calculations tractable. This method captures the impact of the lipid head group using a mean-field-based approach and uses a depth-dependent dielectric constant to characterize the membrane environment. This energy function Franklin2023 (F23) is built upon Franklin2019 (F19), which is based on experimentally derived hydrophobicity scales in the membrane bilayer. We evaluated the performance of F23 on five different tests probing (1) protein orientation in the bilayer, (2) stability, and (3) sequence recovery. Relative to F19, F23 has improved the calculation of the tilt angle of membrane proteins for 90% of WALP peptides, 15% of TM-peptides, and 25% of the adsorbed peptides. The performances for stability and design tests were equivalent for F19 and F23. The speed and calibration of the implicit model will help F23 access biophysical phenomena at long time and length scales and accelerate the membrane protein design pipeline.