Dual chemical bonding construction of electrochemical peptide sensor based on GDY/MOFs(Fe) composite for ultra-low determination of prostate-specific antigen.

A novel "double chemical bonding" electrochemical peptide biosensor 2FcP-GA-GDY(Fe)@NMIL-B was developed for highly selective, ultrasensitive, and ultrastable identification of prostate-specific antigen (PSA). The C-Fe-O chemical bond linking Fe-Graphdiyne (Fe-GDY) with NH2-MIL88B(Fe) (NMIL88B) as the first chemical bonding of electrode carrier Fe-GDY@NH2-MIL88B(Fe) (GDY(Fe)@NMIL) significantly accelerates electron transport. With glutaraldehyde (GA) as a crosslinking agent, the Schiff-base -NC- formed by GDY(Fe)@NMIL nanocomposites links the two Fc molecules labeled peptides (2FcP) as the second chemical bonding, facilitating high-density attachment of peptides to the electrode carrier in a firm manner. When the PSA analyte is introduced to identify and cleave the specific peptide, the release of ferrocene from its head leads to a decrease in the electrical signal, enabling sensitive detection. The prepared sensing platform exhibits exceptional analytical performance for PSA with an extended linear response range from 10 fg mL-1 to 50 ng mL-1. Additionally, the detection limit has been significantly reduced to an ultra-low level of only 0.94 fg mL-1, surpassing those reported in most literature by several orders of magnitude. Moreover, the 2FcP-GA-GDY(Fe)@NMIL-B sensor has excellent selectivity and stability while also showcasing great potential for practical application of PSA detection in human serum using the standard addition method.

A novel approach for 25-gauge transconjunctival sutureless vitrectomy to evaluate vitreous substitutes in rabbits.

AIM: To improve the standard three-port vitrectomy for establishing and evaluating an endotamponade model in rabbits. METHODS: Three ports were prepared near the third eyelid of rabbits, and the infusion port was placed at the inferior nasal quadrant with the inserted cannula linking with a self-designed handheld rigid infusion catheter. All right eyes of rabbits underwent a modified 25-gauge vitrectomy and were subsequently filled with balanced salt solution, silicone oil, and eight-arm polyethylene glycols (8-arm PEGs) hydrogel separately for comparison. Ophthalmic examinations were performed regularly to record the changes after the surgery. RESULTS: Successful vitrectomy was achieved among 44 chinchilla rabbits. The mean operation time was 4.51±1.25min. Four eyes (9.1%) presented limited lens touch and two eyes (4.5%) showed retinal touch during surgery. Incision leakage was found in three eyes (6.8%) after surgery. There was no endophthalmitis, hemorrhage, or retinal detachment during the observation period and ophthalmic examinations after the implantation of vitreous substitutes. CONCLUSION: The modified technique of the standard vitrectomy applied in the endotamponade model in rabbits shows excellent safety and practicality.

Identification of potential crucial genes and mechanisms associated with metastasis of medulloblastoma based on gene expression profile.

OBJECTIVES: Medulloblastoma is the most common malignant brain tumor in childhood. Although metastasis constitutes one of the poorest prognostic indicators in this disease, the mechanisms that drive metastasis have received less attention. The aim of our study is to provide valid biological information for the metastasis mechanism of medulloblastoma. METHODS: Gene expression profile of GSE468 was downloaded from GEO database and was analyzed using limma R package. Function and enrichment analyses of DEGs were performed based on PANTHER database. PPI network construction, hub gene selection and module analysis were conducted in Cytoscape software. RESULTS: Nine upregulated genes and 34 downregulated genes were selected as DEGs. The upregulated genes were mainly enriched in molecular function and cell component, which mainly included protein binding and nucleus respectively. A total of 120 enriched GO terms and 40 KEGG pathways were identified. The main enriched GO terms were the biological process such as apoptosis and MAPK activity. Besides, the enriched KEGG pathways also included MAPK signaling pathway. A PPI network was obtained, and JUN was identified as a hub gene. Also, we firstly investigated the role and regulatory mechanism of JUN in the metastasis of medulloblastoma. CONCLUSIONS: Through the bioinformatics analysis of the gene microarray in GEO, we found some crucial genes and pathways associated with the metastasis of medulloblastoma.

Efficacy and safety of single-dose dexamethasone implantation for patients with persistent diabetic macular edema: a systematic review and meta-analysis.

PURPOSE: This meta-analysis was conducted to evaluate the efficacy and safety of single-dose dexamethasone implantation for treating persistent DME (diabetic macular edema) refractory to anti-VEGF (anti-vascular endothelial growth factor) drugs over a period of 6 months. METHODS: All related clinical trials were reviewed by searching electronic databases of PubMed, Medline, Web of Science, Cochrane Library, and EMBASE. The primary outcome parameters were best-corrected visual acuity (BCVA) and central macular thickness (CMT). We performed this meta-analysis by using Stata15.0. RESULTS: Ten clinical trials involving 362 eyes from 328 patients were eligible in the final analysis. After single-dose dexamethasone implantation, there was a significant improvement in BCVA from baseline to 1, 3, and 6 months with an average increase of - 0.15 logMAR (p < 0.001), - 0.14 logMAR (p < 0.001), and - 0.07 logMAR (p = 0.004), respectively. Further, mean CMT decreased significantly with an average reduction of 249.18 µm (p < 0.001), 217.66 µm (p < 0.001), and 91.56 µm (p < 0.001) at months 1, 3, and 6, respectively. CONCLUSIONS: Our results indicate that switching to a dexamethasone implant could achieve significant anatomical and functional improvement among patients with refractory DME. Clinicians should be aware of this treatment option in refractory DME.

Outcomes of the flanged intrascleral haptic fixation with double-needle technique in patients with Marfan syndrome.

PURPOSE: To investigate the clinical outcomes and complications associated with the flanged intrascleral haptic fixation with double-needle technique (a.k.a. the Yamane technique/FIHFT) in patients with Marfan syndrome (MFS) with subluxated or dislocated lenses. METHODS: Eighteen eyes of 11 patients with MFS with subluxated or dislocated lenses who had undergone intraocular lens implantation using the FIHFT from March 2019 to October 2020 were evaluated. All patient data were retrospectively collected from medical records, including a complete ophthalmologic examination at baseline and follow-up examinations of uncorrected visual acuity (UCVA, logMAR), best-corrected visual acuity (BCVA, logMAR), intraocular pressure (IOP), and slit-lamp examination. RESULTS: The median follow-up period was 6 ± 3 (range, 3-12) months. The average patient age at the time of surgery was 13 ± 9 (range, 4-34) years. The mean preoperative BCVA was 0.49 ± 0.20 logMAR (Snellen equivalent visual acuity, 20/60), while the mean postoperative BCVA at the end of follow-up was 0.21 ± 0.14 logMAR (20/30), indicating an improvement of 0.28 ± 0.20 logMAR (20/40) postoperatively (p < 0.001). Postoperative iris capture occurred in six eyes (38.9%). No cases of hypotony, IOP elevation, or vitreous hemorrhage were noted, and no patients developed intraocular lens dislocation, retinal detachment, or endophthalmitis. CONCLUSIONS: To our knowledge, the present study is the first to report outcomes of the FIHFT in patients with MFS. Our findings suggested that scleral lens fixation is safe and effective for improving visual acuity in patients with MFS who have subluxated or dislocated lenses.

Nanomicelles based on X-shaped four-armed peglyated distearylglycerol as long circulating system for doxorubicin delivery.

A novel X-shaped four-armed gemini-like peglyated distearylglycerol (Gemini-PEG2K-GCDS), with two hydrophilic PEG heads and two hydrophobic stearic acid tails, was successfully synthesized and used as a nanomicellar carrier for delivery of doxorubicin. The critical micelle concentration of the amphiphilic copolymer was higher than 10(-6). Mean particle size and zeta potential of DOX-encapsulated Gemini-PEG2K-GCDS nanomicelles (DOX-GNMs) was 20.4nm and+3.91mv, respectively. Encapsulation efficiency of DOX-GNMs was as high as 94.6 and DOX release was pH-dependent from DOX-GNMs, ensuring the stability of nanomicelles in blood circulation and rapid release of DOX in tumor cells. Pharmacokinetic studies in rats following i.v. administration, DOX-GNMs demonstrated longer retention in blood and larger AUC (19.1-fold of t1/2 and 12.9-fold of AUC) compared with DOX solutions (DOX-Sol). Tissue distribution studies indicate that DOX-GNMs had higher tumor accumulation (4.6-fold) and lower heart toxicity in H22 tumor-bearing mice (17.4-fold) at 48h after administration in comparison with DOX-Sol. Moreover, IC50 of DOX-GNMs increased by 3.3-fold, 2.0-fold and 2.3-fold compared with DOX-Sol in P-gp over-expressing MCF-7/Adr cells after 24h, 48h and 72h, internalized via macropinocytosis-mediated and clathrin-mediated endocytosis. This study suggests that Gemini-PEG2K-GCDS nanomicelle is a promising long circulating delivery system for anti-tumor drugs via extended blood circulation and improved tumor distribution.

PEG-stabilized bilayer nanodisks as carriers for doxorubicin delivery.

Spherical nanoparticles as a classic delivery vehicle for anticancer drugs have been extensively investigated, but study on the shape of nanoparticles has received little attention until now. Here, a nonspherical poly(ethylene glycol) (PEG)-stabilized bilayer nanodisk consisting of 1,2-distearyl-sn-glycero-3-phosphocholine (DSPC) and PEG5000-glyceryl distearate (PEG5K-GCDS) was prepared for doxorubicin delivery, called DOX-Disks. The prepared disks were open bilayer structures, with a hydrophobic discoid center built by DSPC and a hydrophilic PEG edge. Mean particle diameter of the disk was 80.14 nm, and the disk height was about 6 nm with aspect ratio about 12. Encapsulation efficiency of DOX-Disks was as high as 96.1%, and DOX release from DOX-Disks was pH-dependent (25.6% of total DOX released at 24 h in pH 7.4). The pharmacokinetic performances showed that DOX-Disks demonstrated long circulation time in blood and larger AUC (11.7-fold of t1/2 and 31.7-fold of AUC) in rats compared with DOX solutions (DOX-Sol). Tissue distribution in H22 tumor bearing mice demonstrated higher tumor accumulation (9.7-fold) and lower heart toxicities (25.7-fold) at 48 h after iv administration, in comparison with DOX-Sol. In addition, DOX-Disks exhibited much effectiveness in inhibiting tumor cell growth, and the IC50 values were 2.03, 0.85, and 0.86 µg/mL for DOX-Sol and 0.23, 0.24, and 0.20 µg/mL for DOX-Disks after treatment for 48, 72, and 96 h against MCF-7/Adr cells, respectively. DOX-Disks were taken up into MCF-7/Adr cells via energy-dependent endocytosis processes, involved in clathrin-mediated, macropinocytosis-mediated, and non-clathrin- and non-caveolae-mediated endocytosis pathways. In summary, such PEG-stabilized bilayer nanodisks could be one of the promising carriers for antitumor drugs via extended blood circulation and improved tumor distribution.