Predictive biomarkers of intra-ocular pressure decrease after cataract surgery associated with trabecular washout in patients with pseudo exfoliative glaucoma.

To investigate biomarkers of intra-ocular pressure (IOP) decrease after cataract surgery with trabecular washout in pseudo-exfoliative (PEX) glaucoma. A single-center observational prospective study in PEX glaucoma patients undergoing cataract surgery with trabecular washout (Goniowash) was performed from 2018 to 2021. Age, gender, visual acuity, IOP, endothelial cell count, central corneal thickness, medications, were collected over 16-month follow-up. Multivariable binomial regression models were implemented. 54 eyes (35 subjects) were included. Mean preoperative IOP (IOPBL) was 15.9 ± 3.5 mmHg. Postoperative IOP reduction was significant at 1-month and throughout follow-up (p < 0.01, respectively). IOPBL was a predictive biomarker inversely correlated to IOP decrease throughout follow-up (p < 0.001). At 1 and 12 months of follow-up, IOP decrease concerned 31 (57.4%) and 34 (63.0%) eyes with an average IOP decrease of 17.5% (from 17.6 ± 3.1 to 14.3 ± 2.2 mmHg) and 23.0% (from 17.7 ± 2.8 to 13.5 ± 2.6 mmHg), respectively. Performance (AUC) of IOPBL was 0.85 and 0.94 (p < 0.0001, respectively), with IOPBL threshold ≥ 15 mmHg for 82.1% and 96.8% sensitivity, 84.2% and 75.0% specificity, 1.84 and 3.91 IOP decrease odds-ratio, respectively. All PEX glaucoma patients with IOPBL greater than or equal to the average general population IOP were likely to achieve a significant sustainable postoperative IOP decrease.

XEN 45 Gel Stent Implantation in Open Angle Glaucoma: 5-Year Results of a Prospective Study.

PRCIS: XEN 45 Gel Stent is safe and effective for 3 years. The study results provide useful insight into the outcome of XEN 45 Gel Stent surgery over 5 years in daily clinical practice. PURPOSE: To evaluate 5-year outcomes of XEN 45 gel stent implantation (XEN) in patients with open angle glaucoma. METHODS: This is a prospective, single-center, interventional study. XEN implantation either alone (XEN) or combined with phacoemulsification (Phaco + XEN) was performed on 170 consecutive eyes (126 patients) with uncontrolled intraocular pressure (IOP) or disease progression despite medical treatment. "Complete" surgical success at 60 months was defined as unmedicated IOP ≤15 mm Hg and a relative IOP reduction ≥20% from medicated baseline, while "qualified" success allowed fewer ocular hypotensive medications than at baseline. Other definitions of success with various IOP targets were also analyzed. Secondary outcomes included mean IOP and IOP-lowering medication changes and rates of reoperations. RESULTS: Mean age was 78.1±9.2 years, and 70.3% were female. Mean medicated IOP decreased from 19.8±7.7 mm Hg [19.6±7.1 (XEN) vs. 19.8±7.0 mm Hg (Phaco+XEN)] at baseline to 12.6±3.1 mm Hg [12.5± 3.1 (XEN) vs. 12.6±3.1 (Phaco+XEN)] at 5 years (-37.0%; P < 0.001). Medications decreased from 2.0±1.3 [2.0±1.3 (XEN) vs. 2.0±1.3 (Phaco+XEN)] to 0.8±1.1 [0.8±1.1 (XEN) vs. 0.8±1.1 (Phaco + XEN)] (-60%; P <0.001). Needling was performed in 84 eyes (49%), and 19.4% underwent a secondary surgical intervention. Complete success at 3 years was a strong predictor of success at 5 years (odds ratio: 3.06, P <0.01), while needling was associated with higher rates of failure (odds ratio: 3.6, P <0.01). CONCLUSIONS: At 5 years, XEN gel stent implantation was a safe procedure and achieved clinically meaningful IOP and medication reduction. Success at 3 years is a predictor of success at 5 years. Needling correlates with higher failure rates.

Bilateral Nonpenetrating Deep Sclerectomy: Difference in Outcomes Between First- and Second-Operated Eyes at 24 Months.

BACKGROUND/AIM: The aim of this study was to assess the difference in outcome between the first-operated and the second-operated eyes after nonpenetrating deep sclerectomy (DS), and to identify potential success predictors for the second eye. METHODS: This single-surgeon, retrospective study analyzed the outcomes of all bilateral nonsimultaneous DS with at least 24 months of follow-up. Its main outcome measure was surgical success, defined as unmedicated intraocular pressure (IOP) ≤15 mm Hg associated with a relative reduction ≥20%. RESULTS: In all, 104 eyes of 52 patients who underwent bilateral (standalone or combined) DS, within a mean of 344.3±526.3 days of each other, were analyzed. Postoperatively, the mean medicated IOP decreased from 20.7±7.9 (first-operated eyes) and 19.3±6.6 mm Hg (second-operated eyes) at baseline (P=0.107) to 13.8±4.8 [(-33.3%; P<0.001) first-operated eyes) and 12.7±3.8 mm Hg [(-34.2%; P<0.001) second-operated eyes] after 2 years (P=0.619). Postoperative IOP and treatment reduction, respectively, showed fair (r=0.53) and good (r=0.71) levels of correlation between fellow eyes. The rates of complete success were comparable between first-operated and second-operated eyes (32.7% and 40.4%, respectively; P=0.364). At 2 years, among patients whose first-operated eyes were considered a success, 82.4% of surgeries in second eyes were successful (P=0.001). The odds ratio of a second-operated eye experiencing complete success were 6.32 (P=0.011) if the first-operated eye experienced complete success. CONCLUSIONS: The present study demonstrated a strong association between first-operated and second-operated eyes after DS, in terms of surgical outcomes and IOP reduction. In effect, surgical success in the first-operated eye increases the odds of success in the second eye by 6-fold.

Outcomes of pattern scanning laser trabeculoplasty and selective laser trabeculoplasty: Results from the lausanne laser trabeculoplasty registry.

PURPOSE: To compare the long-term safety and efficacy of pattern scanning laser trabeculoplasty (PSLT) and selective laser trabeculoplasty (SLT). METHODS: This was a retrospective database analysis (Lausanne Laser Trabeculoplasty Registry) of patients having had laser trabeculoplasty (LT) prior to 2017 with a minimum follow-up of 1 year. Inclusion criteria were age ≥40 years and diagnosis of ocular hypertension (OHT) and open-angle glaucoma (OAG). Selective laser trabeculoplasty (SLT) eyes were matched to PSLT eyes according to baseline intraocular pressure (IOP), baseline number of ocular hypotensive medications (OHM) and glaucoma diagnosis. Success was defined as an IOP ≤ 20% from baseline or an IOP equal or lower than baseline accompanied by a reduction in OHM. Multivariate regression models were used to study associations between success and baseline clinical parameters. RESULTS: From 280 eyes in the database, 81 eyes had PSLT and were matched with 81 SLT eyes (162 patients). Mean age was 69.4 ± 12.1 years, and 56.2% were female. Mean IOP was 18.6 ± 5.3 and 18.2 ± 4.1 mmHg at baseline and 15.9 ± 3.0 and 16.0 ± 3.4 mmHg at 12 months and 15.2 ± 2.7 and 16.2 ± 3.4 mmHg at 24 months, for PSLT and SLT, respectively. 60.5% of PSLT and 65.4% of SLT eyes achieved treatment success (p = 0.20). Number of OHM was 1.0 ± 1.0 and 1.4 ± 1.2, respectively (p = 0.052). Baseline IOP (OR = 1.23, p < 0.01) and number of OHM (OR = 1.67, p < 0.01) were associated with success in both PSLT and SLT, while LT modality was not [OR = 0.81 (0.43-1.53), p = 0.52], and a diagnosis of primary OAG was negatively associated (OR = 0.42, p = 0.04). CONCLUSION: Our study did not find any significant differences between PSLT and SLT in terms of safety and efficacy in patients with OHT and glaucoma. Baseline IOP was associated with higher success rates in both procedures. Additional studies are needed to evaluate the outcomes of PSLT in non-Caucasian populations and the ability of repeat PSLT to achieve additional IOP reduction.

SERS spectroscopic approach to study doxorubicin complexes with Fe(2+) ions and drug release from SPION-based nanocarriers.

The aim of this work is to present a surface-enhanced Raman scattering (SERS) spectroscopic approach to study complexes of a frequently used antineoplastic agent, doxorubicin (DOX), with ferrous ions, at sub-micromolar concentrations in aqueous solution. The SERS bands of DOX were assigned according to critical analysis of literature. Prior to the complexation study, the spectral changes related to the drug orientation on the silver surface and to its protonation state were highlighted. The SERS spectra of DOX-Fe(2+) complexes showed several features distinguishing them from the free drug, protonated or not on the phenolic part of its chromophore. The lowest detectable content of the DOX-iron complex in the presence of free DOX was estimated to be 5-10%. This property is particularly interesting from the analytical point of view, since it allows for study of drug-iron interactions upon the drug loading on and release from magnetic drug carriers based on superparamagnetic iron oxide nanoparticles (SPIONs), stabilized with citrate ions or coated with polyethylene glycol (PEG) polymer. Our SERS data indicate that the drug loaded on magnetic nanocarriers as DOX-iron chelate was mainly released in the free DOX form. These results demonstrate the strength of the SERS approach for the study of DOX-iron interactions in relation to delivery issues and drug action mechanisms.

Magnetic nanocarriers of doxorubicin coated with poly(ethylene glycol) and folic acid: relation between coating structure, surface properties, colloidal stability, and cancer cell targeting.

We report the efficient one-step synthesis and detailed physicochemical evaluation of novel biocompatible nanosystems useful for cancer therapeutics and diagnostics (theranostics). These systems are the superparamagnetic iron oxide nanoparticles (SPIONs) carrying the anticancer drug doxorubicin and coated with the covalently bonded biocompatible polymer poly(ethylene glycol) (PEG), native and modified with the biological cancer targeting ligand folic acid (PEG-FA). These multifunctional nanoparticles (SPION-DOX-PEG-FA) are designed to rationally combine multilevel mechanisms of cancer cell targeting (magnetic and biological), bimodal cancer cell imaging (by means of MRI and fluorescence), and bimodal cancer treatment (by targeted drug delivery and by hyperthermia effect). Nevertheless, for these concepts to work together, the choice of ingredients and particle structure are critically important. Therefore, in the present work, a detailed physicochemical characterization of the organic coating of the hybrid nanoparticles is performed by several surface-specific instrumental methods, including surface-enhanced Raman scattering (SERS) spectroscopy, X-ray photoelectron spectrometry (XPS), and time-of-flight secondary ion mass spectrometry (ToF-SIMS). We demonstrate that the anticancer drug doxorubicin is attached to the iron oxide surface and buried under the polymer layers, while folic acid is located on the extreme surface of the organic coating. Interestingly, the moderate presence of folic acid on the particle surface does not increase the particle surface potential, while it is sufficient to increase the particle uptake by MCF-7 cancer cells. All of these original results contribute to the better understanding of the structure-activity relationship for hybrid biocompatible nanosystems and are encouraging for the applications in cancer theranostics.

Transferrin adsorption onto PLGA nanoparticles governs their interaction with biological systems from blood circulation to brain cancer cells.

PURPOSE: Nanomedicines represent an alternative for the treatment of aggressive glioblastoma tumors. Behaviour of PLGA-nanoparticles (NPs) was here investigated as a function of their protein adsorption characteristics at the different biological interfaces they are expected to face in order to reach brain cancer cells. METHODS: NPs were studied for size, zeta potential, blood half-life, in vitro endocytic behavior and in vivo accumulation within healthy rat brain and brain tumors. RESULTS: While slightly modifying size (80 to 90 nm) and zeta potential (-44 to -32 mV) protein coating of PLGA-NPs by bovine serum albumin (BSA) or transferrin (Tf) greatly prolonged their blood half-life when intravenously injected in rats and mice. In contrast with THP-1 monocytes, differentiated THP-1 macrophages, F98 glioma cells and astrocytes internalized BSA- and Tf-NPs in vitro. Increase of Tf-NP uptake by F98 cells through caveolae- and clathrin-mediated pathways supports specific interaction between Tf and overexpressed Tf-receptor. Finally, in vivo targeting of healthy brain was found higher with Tf-NPs than with BSA-NPs while both NPs entered massively within brain-developed tumors. CONCLUSION: Taken together, those data evidence that Tf-NPs represent an interesting nanomedicine to deliver anticancer drugs to glioma cells through systemic or locoregional strategies at early and late tumor stages.

The importance of endo-lysosomal escape with lipid nanocapsules for drug subcellular bioavailability.

To establish the therapeutic relevance of new nanocarriers, rationalization of knowledge on their interactions with biological structures is essential. In the present study, we have investigated endocytosis and intracellular trafficking of lipid nanocapsules (LNCs) in rat glioma cells. Radiolabelled and fluorescent LNCs were synthesized by using a phase inversion process that follows the formation of an oil/water microemulsion containing triglycerides, lecithins and a non-ionic surfactant, the hydroxystearate of poly(ethylene glycol) (HS-PEG). Our data revealed that LNCs were rapidly accumulated within cells (from 2 min exposure) through active and saturating mechanisms involving endogenous cholesterol with a major contribution of clathrin/caveolae-independent pathways. Although initially present in endosomes, LNCs can bypass the endo-lysosomal compartment with only 10% of the cell-internalized fraction found in isolated lysosomes after 2 h exposure. As demonstrated by use of lysosomal probes, LNCs reverted lysosome integrity similarly to V-ATPase inhibitors and in a size-dependent fashion with best efficiency for small nanoparticles. When loaded with paclitaxel, smallest LNCs also triggered the best cell death activity. Those LNC properties are ascribed to the proportion of HS-PEG they provided to the cell. They are important to consider toward the development of nanomedicines that use drugs sensitive to lysosomal degradation or that need to reach extra endo-lysosomal targets.

In vivo evaluation of intracellular drug-nanocarriers infused into intracranial tumours by convection-enhanced delivery: distribution and radiosensitisation efficacy.

The objective of the present study was to investigate the interest of convection-enhanced delivery (CED) for the administration of a nanocarrier-based radiosensitizing chemotherapy in the rat brain. Pursuing on newly developed lipid nanocapsules (LNC) that can be internalised within brain tumour cells, we studied their intracerebral distribution when labelled with fluorescent Nile red (NR). As paclitaxel (Px) represents an interesting radiosensitiser, we also evaluated the potential radiosensitising effects of Px-loaded LNC administered through CED in the 9L intracranial rat glioblastoma model. The distribution study demonstrated that CED injection of NR-loaded LNC (NR-LNC) improved significantly the volume of distribution of NR when matched with simple injection (by about 150 fold). It also reveals that the LNC perfusion of a whole tumour forming area inside the CNS (6 days after implantation of 10(3) 9L cells) is achievable through CED injection, whilst preserving the ability of LNC to reach the intracellular space of encountered tumour cells. Having established an animal model of encephalic irradiation close to the clinic (18 Gray in three fractions of six Gray at days 8, 11 and 14 after 9L cell implantation) we proved the feasibility of the combination of CED for the administration of drug-loaded LNC with external beam therapy. Although a single CED injection of Px-LNC at low Px dose (375 mug/kg of bodyweight) gave the best median survival (twice that of untreated controls), it underlines the need for optimisation. Hence, the possibility of grafting recognition moieties onto the LNC surface combined to their biocompatibility must be beneficial.

Positively-charged, porous, polysaccharide nanoparticles loaded with anionic molecules behave as 'stealth' cationic nanocarriers.

PURPOSE: Stealth nanoparticles are generally obtained after modifying their surface with hydrophilic polymers, such as PEG. In this study, we analysed the effect of a phospholipid (DG) or protein (BSA) inclusion in porous cationic polysaccharide (NP(+)) on their physico-chemical structure and the effect on complement activation. METHODS: NP(+)s were characterised in terms of size, zeta potential (zeta) and static light scattering (SLS). Complement consumption was assessed in normal human serum (NHS) by measuring the residual haemolytic capacity of the complement system. RESULTS: DG loading did not change their size or zeta, whereas progressive BSA loading lightly decreased their zeta. An electrophoretic mobility analysis study showed the presence of two differently-charged sublayers at the NP(+) surface which are not affected by DG loading. Complement system activation, studied via a CH50 test, was suppressed by DG or BSA loading. We also demonstrated that NP(+)s could be loaded by a polyanionic molecule, such as BSA, after their preliminary filling by a hydrophobic molecule, such as DG. CONCLUSION: These nanoparticles are able to absorb large amounts of phospholipids or proteins without change in their size or zeta potential. Complement studies showed that stealth behaviour is observed when they are loaded and saturated either with anionic phospholipid or proteins.

Influence of surface charge and inner composition of porous nanoparticles to cross blood-brain barrier in vitro.

The aim of these studies was to evaluate the binding, uptake and transcytosis of 60 nm porous nanoparticles (NPs) that differed in their surface charge and inner composition on the blood-brain barrier (BBB). They were prepared from maltodextrins derived with or without a cationic ligand. In the cationic NPs an anionic lipid was inserted in their core to give DPPG-NPs. The data showed that at 4 degrees C the three NPs bind in different areas on endothelial cells: cationic NPs were found mainly around the paracellular area, while neutral NPs were mainly on the cell surface and DPPG-NPs binding was found at both paracellular areas and on the surface of the cells. At 37 degrees C neutral and cationic NPs had similar degrees of binding and uptake and were transcytosed. Filipin treatment increased their binding and uptake suggesting that sterols are implied in their efflux. Neutral NPs transcytosis was also inhibited by filipin. This inhibition shows that neutral NPs, like LDL in this model, use the caveolae pathway. Neutral and cationic 60 nm porous NPs are potential candidates for drug delivery to the brain.

A new generation of anticancer, drug-loaded, colloidal vectors reverses multidrug resistance in glioma and reduces tumor progression in rats.

By focusing on rat glioma, we elucidated whether new lipid nanocapsules (LNC) were able to improve anticancer hydrophobic drug bioavailability while also overcoming multidrug resistance. Blank LNCs and LNCs loaded with the antineoplastic agent paclitaxel were formulated by an emulsion inversion phase process. Expression of efflux pumps by rat glioma cells was assessed by reverse transcription-PCR, Western blot, and immunohistochemistry, and their activity was followed using the tracer (99)Tc(m)-methoxyisobutylisonitrile. Modalities of LNC action were addressed by using confocal microscopy detection of fluorescently labeled LNCs, fluorescence-activated cell sorting, high-performance liquid chromatography measurement of paclitaxel release, and analysis of tumor cell growth. This revealed an interaction between LNCs and efflux pumps that resulted in an inhibition of multidrug resistance in glioma cells, both in culture and in cell implants in animals. LNCs were able to target the intracellular compartment of glioma cells, a mechanism that was abrogated by using intracellular cholesterol inhibitors but not by clathrin-coated pit or caveolae uptake inhibitors. This result can be correlated to the LNC inhibitory effects on efflux pump activity that is itself known to be stimulated by intracellular cholesterol. In parallel, we showed that paclitaxel-loaded LNCs were active reservoirs from which paclitaxel could be released. Finally, we established that paclitaxel-loaded LNCs were more efficient than the commercially available paclitaxel formulation (Taxol) for clinical use, thus reducing tumor expansion in vitro and in vivo. Considering the physiologically compatible nature of LNC excipients, these data may represent an important step towards the development of new clinical therapeutic strategies against cancers.