Quantification of Budesonide Retained in the Sinonasal Cavity After High-Volume Saline Irrigation in Post-Operative Chronic Rhinosinusitis.

BACKGROUND: Budesonide high-volume saline irrigations (HVSIs) are routinely used to treat chronic rhinosinusitis (CRS) due to improved sinonasal delivery and efficacy compared to intranasal corticosteroid sprays. The off-label use of budesonide is assumed to be safe, with several studies suggesting the systemically absorbed dose of budesonide HVSI is low. However, the actual budesonide dose retained in the sinonasal cavity following HVSI is unknown. The objective of this study was to quantify the retained dose of budesonide after HVSI. METHODS: Adult patients diagnosed with CRS who had undergone endoscopic sinus surgery (ESS) and were prescribed budesonide HVSI were enrolled into a prospective, observational cohort study. Patients performed budesonide HVSI (0.5 mg dose) under supervision in an outpatient clinic, and irrigation effluent was collected. High-performance liquid chromatography was employed to determine the dose of budesonide retained after HVSI. RESULTS: Twenty-four patients met inclusion criteria. The average corrected retained dose of budesonide across the cohort was 0.171 ± 0.087 mg (37.9% of administered budesonide). Increased time from ESS significantly impacted the measured retained dose, with those 3 months post-ESS retaining 27.4% of administered budesonide (P = .0004). CONCLUSION: The retained dose of budesonide in patients with CRS after HVSI was found to be significantly higher than previously estimated and decreased with time post-ESS. Given that budesonide HVSI is a cornerstone of care in CRS, defining the retained dose and the potential systemic implications is critical to understanding the safety of budesonide HVSI.

Reducing hydrophobic drug adsorption in an in-vitro extracorporeal membrane oxygenation model.

Extracorporeal membrane oxygenation (ECMO) is a life-saving cardiopulmonary bypass technology for critically ill patients with heart and lung failure. Patients treated with ECMO receive a range of drugs that are used to treat underlying diseases and critical illnesses. However, the dosing guidelines for these drugs used in ECMO patients are unclear. Mortality rate for patients on ECMO exceeds 40% partly due to inaccurate dosing information, caused in part by the adsorption of drugs in the ECMO circuit and its components. These drugs range in hydrophobicity, electrostatic interactions, and pharmacokinetics. Propofol is commonly administered to ECMO patients and is known to have high adsorption rates to the circuit components due to its hydrophobicity. To reduce adsorption onto the circuit components, we used micellar block copolymers (Poloxamer 188TM and Poloxamer 407TM) and liposomes tethered with poly(ethylene glycol) to encapsulate propofol, provide a hydrophilic shell and prevent its adsorption. Size, polydispersity index (PDI), and zeta potential of the delivery systems were characterized by dynamic light scattering, and encapsulation efficiency was characterized using High Performance Liquid Chromatography (HPLC). All delivery systems used demonstrated colloidal stability at physiological conditions for seven days, cytocompatibility with a human leukemia monocytic cell line, i.e., THP-1 cells, and did not activate the complement pathway in human plasma. We demonstrated a significant reduction in adsorption of propofol in an in-vitro ECMO model upon encapsulation in micelles and liposomes. These results show promise in reducing the adsorption of hydrophobic drugs to the ECMO circuits by encapsulation in nanoscale structures tethered with hydrophilic polymers on the surface.

Clinical pharmacokinetics of atropine oral gel formulation in healthy volunteers.

Sialorrhea or drooling is a common problem in children and adults with neurodevelopmental disorders. It can negatively impact the quality of life due to its physical and psychological manifestations. Providers commonly prescribe atropine eye drops for topical administration to the oral mucosa, as an off-label treatment to manage sialorrhea. However, the off-label use of atropine eye drops can be associated with medication and dosing errors and systemic side effects. To address these limitations of treatment, we developed a mucoadhesive topical oral gel formulation of atropine as an alternative route to off-label administration of atropine eye drops. In this clinical pharmacokinetic (PK) study, we evaluated the safety and PK of atropine gel (0.01% w/w) formulation after single-dose administration to the oral mucosa in 10 healthy volunteers. The PK data showed that after topical administration to the oral mucosa, atropine followed a two-compartment PK profile. The maximum plasma concentration and area under the curve extrapolated to infinite time were 0.14 ng/mL and 0.74 h·ng·mL-1 , respectively. The absorption rate constant calculated by the compartmental analysis was 0.4 h-1 . Safety parameters, such as heart rate, blood pressure, and oxygen saturation, did not significantly change before and after administration of the gel formulation, and no adverse events were observed in all participants who received atropine gel. These data indicate that atropine gel formulation has a satisfactory PK profile, is well-tolerated at the dose studied, and can be further considered for clinical development as a drug product to treat sialorrhea.

Direct and continuous dosing of propofol can saturate Ex vivo ECMO circuit to improve propofol recovery.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) is a cardiopulmonary bypass device that provides life-saving complete respiratory and cardiac support in patients with cardiorespiratory failure. The majority of drugs prescribed to patients on ECMO lack a dosing strategy optimized for ECMO patients. Several studies demonstrated that dosing is different in this population because the ECMO circuit components can adsorb drugs and affect drug exposure substantially. Saturation of ECMO circuit components by drug disposition has been posited but has not been proven. In this study, we have attempted to determine if propofol adsorption is saturable in ex vivo ECMO circuits. METHODS: We injected ex vivo ECMO circuits with propofol, a drug that is highly adsorbed to the ECMO circuit components. Propofol was injected as a bolus dose (50 µg/mL) and a continuous infusion dose (6 mg/h) to investigate the saturation of the ECMO circuit. RESULTS: After the bolus dose, only 27% of propofol was recovered after 30 minutes which is as expected. However, >80% propofol was recovered after the infusion dose which persisted even when the infusion dose was discontinued. CONCLUSION: Our results suggest that if ECMO circuits are dosed directly with propofol, drug adsorption can be eliminated as a cause for altered drug exposure. Field of Research: Artificial Lung/ECMO.

Matrix-Mediated Delivery of Silver Nanoparticles for Prevention of Staphylococcus aureus and Pseudomonas aeruginosa Biofilm Formation in Chronic Rhinosinusitis.

Chronic rhinosinusitis (CRS) is a chronic health condition affecting the sinonasal cavity. CRS-associated mucosal inflammation leads to sinonasal epithelial cell death and epithelial cell barrier disruption, which may result in recurrent bacterial infections and biofilm formation. For patients who fail medical management and elect endoscopic sinus surgery for disease control, bacterial biofilm formation is particularly detrimental, as it reduces the efficacy of surgical intervention. Effective treatments that prevent biofilm formation in post-operative patients in CRS are currently limited. To address this unmet need, we report the controlled release of silver nanoparticles (AgNps) with silk-elastinlike protein-based polymers (SELPs) to prevent bacterial biofilm formation in CRS. This polymeric network is liquid at room temperature and forms a hydrogel at body temperature, and is hence, capable of conforming to the sinonasal cavity upon administration. SELP hydrogels demonstrated sustained AgNp and silver ion release for the studied period of three days, potent in vitro antibacterial activity against Pseudomonas aeruginosa (**** p < 0.0001) and Staphylococcus aureus (**** p < 0.0001), two of the most commonly virulent bacterial strains observed in patients with post-operative CRS, and high cytocompatibility with human nasal epithelial cells. Antibacterial controlled release platform shows promise for treating patients suffering from prolonged sinonasal cavity infections due to biofilms.

In Vitro Safety Assessment of In-House Synthesized Titanium Dioxide Nanoparticles: Impact of Washing and Temperature Conditions.

Titanium dioxide nanoparticles (TiO2 NPs) have been widely used in food, cosmetics, and biomedical research. However, human safety following exposure to TiO2 NPs remains to be fully understood. The aim of this study was to evaluate the in vitro safety and toxicity of TiO2 NPs synthesized via the Stöber method under different washing and temperature conditions. TiO2 NPs were characterized by their size, shape, surface charge, surface area, crystalline pattern, and band gap. Biological studies were conducted on phagocytic (RAW 264.7) and non-phagocytic (HEK-239) cells. Results showed that washing amorphous as-prepared TiO2 NPs (T1) with ethanol while applying heat at 550 °C (T2) resulted in a reduction in the surface area and charge compared to washing with water (T3) or a higher temperature (800 °C) (T4) and influenced the formation of crystalline structures with the anatase phase in T2 and T3 and rutile/anatase mixture in T4. Biological and toxicological responses varied among TiO2 NPs. T1 was associated with significant cellular internalization and toxicity in both cell types compared to other TiO2 NPs. Furthermore, the formation of the crystalline structure induced toxicity independent of other physicochemical properties. Compared with anatase, the rutile phase (T4) reduced cellular internalization and toxicity. However, comparable levels of reactive oxygen species were generated following exposure to the different types of TiO2, indicating that toxicity is partially driven via non-oxidative pathways. TiO2 NPs were able to trigger an inflammatory response, with varying trends among the two tested cell types. Together, the findings emphasize the importance of standardizing engineered nanomaterial synthesis conditions and evaluating the associated biological and toxicological consequences arising from changes in synthesis conditions.

Systemic administration of budesonide in pegylated liposomes for improved efficacy in chronic rhinosinusitis.

Chronic rhinosinusitis (CRS) is a chronic inflammatory condition affecting the nasal and paranasal sinuses of approximately 11.5% of the United States adult population. Oral corticosteroids are effective in controlling sinonasal inflammation in CRS, but the associated adverse effects limit their clinical use. Topical budesonide has demonstrated clinical efficacy in patients with CRS. Herein, we investigated the systemic delivery of liposomes tethered with poly(ethylene glycol) (PEG) and loaded with budesonide in a murine model of CRS. PEGylated liposomes encapsulated with budesonide phosphate (L-BudP) were administered via tail vein injection, and the feasibility of L-BudP to reduce sinonasal inflammation was compared to that of free budesonide phosphate (F-BudP) and topical budesonide phosphate (T-BudP) treatment over a 14-day study period. Compared to a single injection of F-BudP and repeat T-BudP administration, a single injection of L-BudP demonstrated increased and prolonged efficacy, resulting in the significant improvement of sinonasal tissue histopathological scores (p < 0.05) with decreased immune cell infiltration (p < 0.05). Toxicities associated with L-BudP and T-BudP treatment, assessed via body and organ weight, as well as peripheral blood liver enzyme and differential white blood cell analyses, were transient and comparable. These data suggest that systemic liposomal budesonide treatment results in improved efficacy over topical treatment.

Micellar Encapsulation of Propofol Reduces its Adsorption on Extracorporeal Membrane Oxygenator (ECMO) Circuit.

Extracorporeal membrane oxygenation (ECMO) is a life-saving cardiopulmonary bypass device used on critically ill patients with refractory heart and lung failure. Patients supported with ECMO receive numerous drugs to treat critical illnesses and the underlying diseases. Unfortunately, most drugs prescribed to patients on ECMO lack accurate dosing information. Dosing can be variable in this patient population because the ECMO circuit components can adsorb drugs and affect drug exposure substantially. Propofol is a widely used anesthetic in ECMO patients and is known to have high adsorption rates in ECMO circuits due to its high hydrophobicity. In an attempt to reduce adsorption, we encapsulated propofol with Poloxamer 407 (Polyethylene-Polypropylene Glycol). Size and polydispersity index (PDI) were characterized using dynamic light scattering. Encapsulation efficiency was analyzed using High performance liquid chromatography. Cytocompatibility of micelles was analyzed against human macrophages and the formulation was finally injected in an ex-vivo ECMO circuit to determine the adsorption of propofol. Size and PDI of micellar propofol were 25.5 ± 0.8 nm and 0.08 ± 0.01, respectively. Encapsulation efficiency of the drug was 96.1 ± 1.3%. Micellar propofol demonstrated colloidal stability at physiological temperature for a period of 7 days, and was cytocompatible with human macrophages. Micellar propofol demonstrated a significant reduction in adsorption of propofol in the ECMO circuit at earlier time points compared to free propofol (Diprivan®). We observed 97 ± 2% recovery of the propofol from the micellar formulation after an infusion. These results demonstrate the potential of micellar propofol to reduce drug adsorption to ECMO circuit.

Vascular permeability in HPV+ oropharyngeal cancers aids in fluorescent image-guided transoral robotic surgery using indocyanine green.

BACKGROUND: Indocyanine green (ICG) fluorescent image (FI)-guided surgery has demonstrated success in improving intraoperative visualization and tumor resections. The objectives were to evaluate the use of IGC in FI-guided transoral robotic surgery (TORS) and the underlying molecular mechanism. METHODS: HPV+ oropharyngeal squamous cell carcinoma (OPSCCa) patient (n = 10) undergoing TORS were enrolled in this prospective study. Participants received intravenous ICG. Excised tissues were evaluated for ICG accumulation, tumor demarcation, and pathological characteristics using In-vivo imaging system (IVIS), histology, and RNA sequencing. RESULTS: ICG accumulation was significantly increased in primary tumor and pathological lymph nodes compared with normal tissues (p < 0.001). IVIS was 91.3% accurate in identifying OPSCCa in excised tissues; the correlation between IVIS- and histologically determined tumor tissues was significant (R2 = 0.8301; p = 0.001). Genes associated with vascular and angiogenic signaling pathways were significantly upregulated in OPSCCa tissues. CONCLUSION: ICG effectively demarcates tumor margins in OPSCCa, due to the increased upregulation of genes associated with vascular permeability.

Layer-by-Layer Hollow Mesoporous Silica Nanoparticles with Tunable Degradation Profile.

Silica nanoparticles (SNPs) have shown promise in biomedical applications such as drug delivery and imaging due to their versatile synthetic methods, tunable physicochemical properties, and ability to load both hydrophilic and hydrophobic cargo with high efficiency. To improve the utility of these nanostructures, there is a need to control the degradation profile relative to specific microenvironments. The design of such nanostructures for controlled combination drug delivery would benefit from minimizing degradation and cargo release in circulation while increasing intracellular biodegradation. Herein, we fabricated two types of layer-by-layer hollow mesoporous SNPs (HMSNPs) containing two and three layers with variations in disulfide precursor ratios. These disulfide bonds are redox-sensitive, resulting in a controllable degradation profile relative to the number of disulfide bonds present. Particles were characterized for morphology, size and size distribution, atomic composition, pore structure, and surface area. No difference was observed between in vitro cytotoxicity profiles of the fabricated nanoparticles at 24 h in the concentration range below 100 µg mL-1. The degradation profiles of particles were evaluated in simulated body fluid in the presence of glutathione. The results demonstrate that the composition and number of layers influence degradation rates, and particles containing a higher number of disulfide bridges were more responsive to enzymatic degradation. These results indicate the potential utility of layer-by-layer HMSNPs for delivery applications where tunable degradation is desired.

Silica Nanoparticles Promote Apoptosis in Ovarian Granulosa Cells via Autophagy Dysfunction.

Although silica nanoparticles (SNPs) are generally thought to be biocompatible and safe, the adverse effects of SNPs were also reported in previous studies. SNPs cause follicular atresia via the induction of ovarian granulosa cell apoptosis. However, the mechanisms for this phenomenon are not well understood. This study focuses on exploring the relationship between autophagy and apoptosis induced by SNPs in ovarian granulosa cells. Our results showed that 25.0 mg/kg body weight (b.w.)/intratracheal instillation of 110 nm in diameter spherical Stöber SNPs caused ovarian granulosa cell apoptosis in follicles in vivo. We also found that SNPs mainly internalized into the lumens of the lysosomes in primary cultured ovarian granulosa cells in vitro. SNPs induced cytotoxicity via a decrease in viability and an increase in apoptosis in a dose-dependent manner. SNPs increased BECLIN-1 and LC3-II levels, leading to the activation of autophagy and increased P62 level, resulting in the blockage of autophagic flux. SNPs increased the BAX/BCL-2 ratio and cleaved the caspase-3 level, resulting in the activation of the mitochondrial-mediated caspase-dependent apoptotic signaling pathway. SNPs enlarged the LysoTracker Red-positive compartments, decreased the CTSD level, and increased the acidity of lysosomes, leading to lysosomal impairment. Our results reveal that SNPs cause autophagy dysfunction via lysosomal impairment, resulting in follicular atresia via the enhancement of apoptosis in ovarian granulosa cells.

Targeting Intratibial Osteosarcoma Using Water-Soluble Copolymers Conjugated to Collagen Hybridizing Peptides.

Osteosarcoma (OS) is the most common form of primary malignant bone cancer in adolescents. Over the years, OS prognosis has greatly improved due to adjuvant and neoadjuvant (preoperative) chemotherapeutic treatment, increasing the chances of successful surgery and reducing the need for limb amputation. However, chemotherapeutic treatment to treat OS is limited by off-target toxicities and requires improved localization at the tumor site. Collagen, the main constituent of bone tissue, is extensively degraded and remodeled in OS, leading to an increased availability of denatured (monomeric) collagen. Collagen hybridizing peptides (CHPs) comprise a class of peptides rationally designed to selectively bind to denatured collagen. In this work, we have conjugated CHPs as targeting moieties to water-soluble N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers to target OS tumors. We demonstrated increased accumulation of collagen-targeted HPMA copolymer-CHP conjugates compared to nontargeted HPMA copolymers, as well as increased retention compared to both nontargeted copolymers and CHPs, in a murine intratibial OS tumor model. Furthermore, we used microcomputed tomography analysis to evaluate the bone microarchitecture and correlated bone morphometric parameters (porosity, bone volume, and surface area) with maximum accumulation (Smax) and accumulation at 168 h postinjection (S168) of the copolymers at the tumor. Our results provide the foundation for the use of HPMA copolymer-CHP conjugates as targeted drug delivery systems in OS tumors.

Sex-Specific Silica Nanoparticle Protein Corona Compositions Exposed to Male and Female BALB/c Mice Plasmas.

As various nanoparticles (NPs) are increasingly being used in nanomedicine products for more effective and less toxic therapy and diagnosis of diseases, there is a growing need to understand their biological fate in different sexes. Herein, we report a proof-of-concept result of sex-specific protein corona compositions on the surface of silica NPs as a function of their size and porosity upon incubation with plasma proteins of female and male BALB/c mice. Our results demonstrate substantial differences between male and female protein corona profiles on the surface of silica nanoparticles. By comparing protein abundances between male and female protein coronas of mesoporous silica nanoparticles and Stöber silica nanoparticles of ∼100, 50, and 100 nm in diameter, respectively, we detected 17, 4, and 4 distinct proteins, respectively, that were found at significantly different concentrations for these constructs. These initial findings demonstrate that animal sex can influence protein corona formation on silica NPs as a function of the physicochemical properties. A more thorough consideration of the role of plasma sex would enable nanomedicine community to design and develop safer and more efficient diagnostic and therapeutic nanomedicine products for both sexes.

HPMA copolymer-collagen hybridizing peptide conjugates targeted to breast tumor extracellular matrix.

The extracellular matrix (ECM) is dynamically involved in many aspects of cell growth and survival, and it plays an active role in cancer etiology. In comparison to healthy ECM, tumor associated ECM shows high collagen deposition and remodeling activity, which results in an increased amount of denatured collagen strands in tumor tissues. Capitalizing on this distinguishing feature, we developed tumor-localizing polymeric carriers that selectively bind to denatured collagen in the tumor ECM. We synthesized N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers with their side chains conjugated to collagen hybridizing peptides (CHPs). HPMA copolymer-CHP conjugates exhibited selective affinity to denatured collagen and localized to tumors in an orthotopic MDA-MB-231 murine breast cancer model. The conjugates had increased tumor localization compared to copolymers with scrambled peptides in the side chains, as well as increased retention compared to free CHPs. Such conjugates show promise as carriers for ECM-acting drugs and imaging agents in the management of diseases characterized by high ECM remodeling activity.

Silica nanoparticles induce ovarian granulosa cell apoptosis via activation of the PERK-ATF4-CHOP-ERO1α pathway-mediated IP3R1-dependent calcium mobilization.

Ambient particulate matters (PMs) have adverse effects in human and animal female reproductive health. Silica nanoparticles (SNPs), as a major component of PMs, can induce follicular atresia via the promotion of ovarian granulosa cell apoptosis. However, the molecular mechanisms of apoptosis induced by SNPs are not very clear. This work focuses on revealing the mechanisms of ER stress on SNP-induced apoptosis. Our results showed that spherical Stöber SNPs (110 nm, 25.0 mg/kg b.w.) induced follicular atresia via the promotion of granulosa cell apoptosis by intratracheal instillation in vivo; meanwhile, SNPs decreased the viability and increase apoptosis in granulosa cells in vitro. SNPs were taken up and accumulated in the vesicles of granulosa cells. Additionally, our results found that SNPs increased calcium ion (Ca2+) concentration in granulosa cell cytoplasm. Furthermore, SNPs activated ER stress via an increase in the PERK and ATF6 pathway-related protein levels and IP3R1-dependent calcium mobilization via an increase in IP3R1 level. In addition, 4-PBA restored IP3R1-dependent calcium mobilization and decreased apoptosis via the inhibition of ER stress. The ATF4-C/EBP homologous protein (CHOP)-ER oxidoreductase 1 alpha (ERO1α) pathway regulated SNP-induced IP3R1-dependent calcium mobilization and cell apoptosis via ATF4, CHOP, and ERO1α depletion in ovarian granulosa cells. Herein, we demonstrate that ER stress cooperated in SNP-induced ovarian toxicity via activation of IP3R1-mediated calcium mobilization, leading to apoptosis, in which the PERK-ATF4-CHOP-ERO1α pathway plays an essential role in ovarian granulosa cells.

Silk-elastinlike protein-based hydrogels for drug delivery and embolization.

Silk-Elastinlike Protein-Based Polymers (SELPs) can form thermoresponsive hydrogels that allow for the generation of in-situ drug delivery matrices. They are produced by recombinant techniques, enabling exact control of monomer sequence and polymer length. In aqueous solutions SELP strands form physical crosslinks as a function of temperature increase without the addition of crosslinking agents. Gelation kinetics, modulus of elasticity, pore size, drug release, biorecognition, and biodegradation of SELP hydrogels can be controlled by placement of amino acid residues at strategic locations in the polymer backbone. SELP hydrogels have been investigated for delivery of a variety of bioactive agents including small molecular weight drugs and fluorescent probes, oligomers of glycosaminoglycans, polymeric macromolecules, proteins, plasmid DNA, and viral gene delivery systems. In this review we provide a background for use of SELPs in matrix-mediated delivery and summarize recent investigations of SELP hydrogels for controlled delivery of bioactive agents as well as their use as liquid embolics.

Effect of combustion particle morphology on biological responses in a Co-culture of human lung and macrophage cells.

Atmospheric aging of combustion particles alters their chemical composition and morphology. Previous studies have reported differences in toxicological responses after exposure to fresh versus aged particles, with chemical composition being the prime suspect behind the differences. However, less is known about the contribution of morphological differences in atmospherically aged particles to toxicological responses, possibly due to the difficulty in resolving the two properties (composition and morphology) that change simultaneously. This study altered the shape of lab-generated combustion particles, without affecting the chemical composition, from fractal-like to a more compact spherical shape, using a water condensation-evaporation method. The two shapes were exposed to a co-culture of human airway epithelial (A549) and differentiated human monocyte (THP-1) cells at air-liquid interface (ALI) conditions. The particles with different shapes were deposited using an electrostatic field-based ALI chamber. For the same mass dose, both shapes were internalized by cells, induced a pro-inflammatory response (IL-8 and TNFα), and enhanced CYP1A1 gene expression compared to air controls. The more compact spherical particles (representative of atmospherically aged particles) induced more early apoptosis and release of TNFα compared to the more fractal-like particles. These results suggest a contribution of morphology to the increased toxicity of aged combustion-derived particles.

Protein-based polymer liquid embolics for cerebral aneurysms.

Cerebral aneurysms (CA), an abnormal bulge in the arteries that supply blood to the brain, are prone to rupture and can cause hemorrhagic stroke. Physicians can treat CA by blocking blood flow to the aneurysmal sac via clipping of the aneurysm neck via open procedure, or endovascular occlusion of the aneurysm with embolic materials to promote thrombus formation to prevent further inflow of blood into the aneurysm. Endovascular treatment options for CA still have significant limitations in terms of safety, usability in coagulopathic patients, and risks of device migration. Bioactive embolic therapies, consisting of non-toxic bioresorbable materials that encourage the growth of neointima across the aneurysm neck, are needed to improve the healing of CA. In this work, the bioinspired silk-elastinlike protein-based polymer (SELP 815K), was used to embolize aneurysms in a rabbit elastase model. SELP 815K effectively embolized the model aneurysms in vivo, achieving >90% occlusion, using commercial microcatheters. No device-associated adverse effects were observed in any of the animals, and SELP 815K showed no cytotoxicity. SELP embolization did not show any deleterious effects to local tissues, and features consistent with reendothelialization of the aneurysm neck were noted in histological examination one-month post-embolization. SELP 815K shows promise as an embolic treatment for unruptured CA. STATEMENT OF SIGNIFICANCE: Unruptured cerebral aneurysms are present in approximately 3% of the population, with a fatality rate of up to 65% upon rupture. In this work a silk-elastinlike protein polymer (SELP) is explored as a liquid embolic for occlusion of cerebral aneurysms. This embolic exists as a liquid at room temperature before rapidly forming a gel at physiological temperature. This shape filling property was used to successfully occlude cerebral aneurysms in rabbits, with stable occlusion persisting for over thirty days. SELP occlusions show evidence for reendothelialization of the aneurysm sac and provide an opportunity for delivery of bioactive agents to further improve treatments.

BECLIN-1-Mediated Autophagy Suppresses Silica Nanoparticle-Induced Testicular Toxicity via the Inhibition of Caspase 8-Mediated Cell Apoptosis in Leydig Cells.

Accumulation of silica nanoparticles (SNPs) in the testes leads to male reproductive toxicity. However, little is known about the effect and mechanistic insights of SNP-induced autophagy on apoptosis in Leydig cells. In this study, we aimed to verify the role of SNP-induced autophagy in apoptosis and explore the possible underlying mechanism in mouse primary Leydig cells (PLCs). H&E staining showed that SNPs changed the histological structures of the testes, including a reduction in the Leydig cell populations in vivo. CCK-8 assay showed that SNPs decreased cell viability, and flow cytometry showed that SNPs increased cell apoptosis, both in a dose-dependent manner in vitro. Additionally, Western blotting further found that SNPs activated autophagy by an increase in BECLIN-1, ATG16L, and LC3-II levels and promoted the intrinsic pathway of apoptosis by an increase in the BAX/BCL-2 ratio, cleaved the caspase 8 and caspase 3 levels. Furthermore, autophagy decreased SNP-induced apoptosis via regulation of the caspase 8 level combined with rapamycin, 3-methyladenine, and chloroquine. BECLIN-1 depletion increased the caspase 8 level, leading to an increase in SNP-induced cell apoptosis. Collectively, this evidence demonstrates that SNPs activated BECLIN-1-mediated autophagy, which prevented SNP-induced testicular toxicity via the inhibition of caspase 8-mediated cell apoptosis in Leydig cells.