Poly-ε-caprolactone based nanoparticles for delivery of genistein in melanoma treatment

Abstract We developed poly-ε-caprolactone (PCL)-based nanoparticles containing D-α-tocopherol polyethylene glycol-1000 succinate (TPGS) or Poloxamer 407 as stabilizers to efficiently encapsulate genistein (GN). Two formulations, referred to as PNTPGS and PNPol, were prepared using nanoprecipitation. They were characterized by size and PDI distribution, zeta potential, nanoparticle tracking analysis (NTA), GN association (AE%), infrared spectroscopy (FT-IR), and differential scanning calorimetry (DSC). PNTPGS-GN exhibited a particle size of 141.2 nm, a PDI of 0.189, a zeta potential of -32.9 mV, and an AE% of 77.95%. PNPol-GN had a size of 146.3 nm, a better PDI than PNTPGS-GN (0.150), a less negative zeta potential (-21.0 mV), and an AE% of 68.73%. Thermal and spectrometric analyses indicated that no new compounds were formed, and there was no incompatibility detected in the formulations. Cellular studies revealed that Poloxamer 407 conferred less toxicity to PCL nanoparticles. However, the percentage of uptake decreased compared to the use of TPGS, which exhibited almost 80% cellular uptake. This study contributes to the investigation of stabilizers capable of conferring stability to PCL nanoparticles efficiently encapsulating GN. Thus, the PCL nanoparticle proposed here is an innovative nanomedicine for melanoma therapy and represents a strong candidate for specific pre-clinical and in vivo studies.

Implants and spacers for paralytic ectropion: Literature review and assessment of a thin-profile porous polyethylene implant

Purpose: There is no ideal treatment paradigm for paralytic ectropion. This study evaluated lower eyelid spacers and the efficacy of a novel lower eyelid thin profile, bio?integratable, porous polyethylene. Methods: A retrospective review of 15 consecutive patients who underwent thin?profile porous polyethylene implantation and canthoplasty for paralytic ectropion was carried out. A comprehensive literature review of spacers for paralytic ectropion and retraction using the Pubmed database with search terms “[implant or graft or spacer] and [paralytic ectropion or paralytic retraction],” “graft and paralysis and ectropion,” “implant and paralysis and ectropion,” “graft and paralysis and retraction,” and “implant and paralysis and retraction” was carried out. Results: The mean patient age was 69 years (range: 50–88). Lagophthalmos improved from a mean of 5.7 mm (SD = 3.3, range 3–14 mm) to 1.4 mm (SD = 1.1, range 0–3.5 mm), P < 0.0001. MRD 2 improved from a mean of 6.7 mm (SD = 2.3, range 2–12 mm) to 4.2 mm (SD = 0.9, range 3–6 mm), P = 0.0005. No patients needed additional lower eyelid surgery. There were no implant exposures at a mean follow?up of 7.6 months (SD = 7.9, range 0.7–21.6 months). Detailed literature review revealed that hard palate and ear cartilage are the most reported spacers, each with unique disadvantages. Conclusion: The thin?profile porous polyethylene implant is a useful addition to the management of symptomatic paralytic ectropion. Meaningful comparison of lower eyelid spacers is difficult because of variations in surgical technique, spacer size, and poorly reported outcome data. No spacer proves superior

Preparation of an ophthalmic formulation of TPGS-modified insulin-loaded liposomes and its in vitro corneal permeation and pharmacokinetics in rabbit eyes / 南方医科大学学报

OBJECTIVE@#To prepare vitamin E polyethylene glycol 1000 succinate (TPGS)-modified insulin-loaded liposomes (T-LPs/INS) and evaluate its safety, corneal permeability, ocular surface retention and pharmacokinetics in rabbit eyes.@*METHODS@#The safety of the preparation was investigated in human corneal endothelial cells (HCECs) using CCK8 assay and live/dead cell staining. In the ocular surface retention study, 6 rabbits were randomized into 2 equal groups for application of fluorescein sodium dilution or T-LPs/INS labeled with fluorescein in both eyes, which were photographed under cobalt blue light at different time points. In the cornea penetration test, another 6 rabbits divided into 2 groups for application of Nile red diluent or T-LPs/INS labeled with Nile red in both eyes, after which the corneas were harvested for microscopic observation. In the pharmacokinetic study, 2 groups of rabbits (n=24) were treated with eye drops of T-LPs/INS or insulin, and the aqueous humor and cornea were collected at different time points for measurement of insulin concentrations using enzyme linked immunosorbent assay. DAS2 software was used to analyze the pharmacokinetic parameters.@*RESULTS@#The prepared T-LPs/INS showed good safety in cultured HCECs. Corneal permeability assay and fluorescence tracer ocular surface retention assay demonstrated a significantly higher corneal permeability of T-LPs/INS with a prolonged drug residence in the cornea. In the pharmacokinetic study, insulin concentrations in the cornea at 6, 15, 45, 60, and 120 min (P < 0.01) and in the aqueous humor at 15, 45, 60, and 120 min after dosing were significantly higher in T-LPs/INS group. The changes in insulin concentrations in the cornea and aqueous humor were consistent with a two-compartment model in T-LPs/INS group and with the one-compartment model in the insulin group.@*CONCLUSION@#The prepared T-LPs/INS shows an improved corneal permeability, ocular surface retention capacity and eye tissue concentration of insulin in rabbits.

A novel bioassay to assess bioactivity of PEG-rhGH using Nb2-11 cells / 药学学报

In this study, we established a novel bioassay to determine the activity of polyethylene glycolated recombinant human growth hormone (PEG-rhGH) using Nb2-11 cells. We performed experimental condition optimization and methodological verification, and then detected the relative potency of PEG-rhGH products using this method. We demonstrated that the bioactivity of PEG-rhGH in promoting Nb2-11 cell proliferation displays a dose-response relationship, which conformed to the four-parameter model. Using PEG-rhGH reference as a control, we analyzed the relative potency of six batches of PEG-rhGH products, as well as linearity, regression and parallelism of the obtained curves. The relative potency of six batches of PEG-rhGH products was 95% to 105%. These results implied that the new bioassay established may be employed in quality control of PEG-rhGH products.

Engineering the plastic degradation enzyme Ple629 from marine consortium to improve its thermal stability / 生物工程学报

Petrochemical-derived polyester plastics such as polyethylene terephthalate (PET) and polybutylene adipate terephthalate (PBAT) have been widely used. However, the difficulty to be degraded in nature (PET) or the long biodegradation cycle (PBAT) resulted in serious environmental pollution. In this connection, treating these plastic wastes properly becomes one of the challenges of environment protection. From the perspective of circular economy, biologically depolymerizing the waste of polyester plastics and reusing the depolymerized products is one of the most promising directions. Recent years have seen many reports on polyester plastics degrading organisms and enzymes. Highly efficient degrading enzymes, especially those with better thermal stability, will be conducive to their application. The mesophilic plastic-degrading enzyme Ple629 from the marine microbial metagenome is capable of degrading PET and PBAT at room temperature, but it cannot tolerate high temperature, which hampers its potential application. On the basis of the three-dimensional structure of Ple629 obtained from our previous study, we identified some sites which might be important for its thermal stability by structural comparison and mutation energy analysis. We carried out transformation design, and performed expression, purification and thermal stability determination of the mutants. The melting temperature (Tm) values of mutants V80C and D226C/S281C were increased by 5.2 ℃ and 6.9 ℃, respectively, and the activity of mutant D226C/S281C was also increased by 1.5 times compared with that of the wild-type enzyme. These results provide useful information for future engineering and application of Ple629 in polyester plastic degradation.

Enzymatic properties and degradation characterization of a bis(2-hydroxyethyl) terephthalate hydrolase from Saccharothrix sp / 生物工程学报

The discovery of new enzymes for poly(ethylene terephthalate) (PET) degradation has been a hot topic of research globally. Bis-(2-hydroxyethyl) terephthalate (BHET) is an intermediate compound in the degradation of PET and competes with PET for the substrate binding site of the PET-degrading enzyme, thereby inhibiting further degradation of PET. Discovery of new BHET degradation enzymes may contribute to improving the degradation efficiency of PET. In this paper, we discovered a hydrolase gene sle (ID: CP064192.1, 5085270-5086049) from Saccharothrix luteola, which can hydrolyze BHET into mono-(2-hydroxyethyl) terephthalate (MHET) and terephthalic acid (TPA). BHET hydrolase (Sle) was heterologously expressed in Escherichia coli using a recombinant plasmid, and the highest protein expression was achieved at a final concentration of 0.4 mmol/L of isopropyl-β-d-thiogalactoside (IPTG), an induction duration of 12 h and an induction temperature of 20 ℃. The recombinant Sle was purified by nickel affinity chromatography, anion exchange chromatography, and gel filtration chromatography, and its enzymatic properties were also characterized. The optimum temperature and pH of Sle were 35 ℃ and 8.0, and more than 80% of the enzyme activity could be maintained in the range of 25-35 ℃ and pH 7.0-9.0 and Co2+ could improve the enzyme activity. Sle belongs to the dienelactone hydrolase (DLH) superfamily and possesses the typical catalytic triad of the family, and the predicted catalytic sites are S129, D175, and H207. Finally, the enzyme was identified as a BHET degrading enzyme by high performance liquid chromatography (HPLC). This study provides a new enzyme resource for the efficient enzymatic degradation of PET plastics.

Advances in poly(ethylene terephthalate) hydrolases / 生物工程学报

Plastics have brought invaluable convenience to human life since it was firstly synthesized in the last century. However, the stable polymer structure of plastics led to the continuous accumulation of plastic wastes, which poses serious threats to the ecological environment and human health. Poly(ethylene terephthalate) (PET) is the most widely produced polyester plastics. Recent researches on PET hydrolases have shown great potential of enzymatic degradation and recycling of plastics. Meanwhile, the biodegradation pathway of PET has become a reference model for the biodegradation of other plastics. This review summarizes the sources of PET hydrolases and their degradation capacity, degradation mechanism of PET by the most representative PET hydrolase-IsPETase, and recently reported highly efficient degrading enzymes through enzyme engineering. The advances of PET hydrolases may facilitate the research on the degradation mechanism of PET and further exploration and engineering of efficient PET degradation enzymes.

Polyethylene biodegradation: current status and perspectives / 生物工程学报

Polyethylene (PE) is the most abundantly used synthetic resin and one of the most resistant to degradation, and its massive accumulation in the environment has caused serious pollution. Traditional landfill, composting and incineration technologies can hardly meet the requirements of environmental protection. Biodegradation is an eco-friendly, low-cost and promising method to solve the plastic pollution problem. This review summarizes the chemical structure of PE, the species of PE degrading microorganisms, degrading enzymes and metabolic pathways. Future research is suggested to focus on the screening of high-efficiency PE degrading strains, the construction of synthetic microbial consortia, the screening and modification of degrading enzymes, so as to provide selectable pathways and theoretical references for PE biodegradation research.

Commentary: polymer binding modules accelerate enzymatic degradation of poly(ethylene terephthalate) / 生物工程学报

The large scale production and indiscriminate use of plastics led to serious environmental pollution. To reduce the negative effects of plastics waste on the environment, an approach of enzymatic degradation was put forward to catalyze plastics degradation. Protein engineering strategies have been applied to improve the plastics degrading enzyme properties such as activity and thermal stability. In addition, polymer binding modules were found to accelerate the enzymatic degradation of plastics. In this article, we introduced a recent work published in Chem Catalysis, which studied the role of binding modules in enzymatic hydrolysis of poly(ethylene terephthalate) (PET) at high-solids loadings. Graham et al. found that binding modules accelerated PET enzymatic degradation at low PET loading (< 10 wt%) and the enhanced degradation cannot be observed at high PET loading (10 wt%-20 wt%). This work is beneficial for the industrial application of polymer binding modules in plastics degradation.

Meta-analysis of different joint interfaces in total hip arthroplasty under long-term follow-up / 中国骨伤

OBJECTIVE@#To compare the long-term follow-up effect and complications of ceramic on ceramic (CoC) interface and ceramic on polyethyleneon ceramic (CoP) interface in primary total hip arthroplasty, and provide clinical evidence.@*METHODS@#Search PubMed, EMBase, the CoChrane Library databases, Web of science, Wanfang database, and CNKI from January 2000 to September 2021, screening and inclusion of randomized controlled trials (RCTs) comparing the long-term efficacy and complications of CoC interface and CoP interface in total hip arthroplasty. Literature screening, quality evaluation and data extraction were carried out according to the inclusion and exclusion criteria, using Review Manager 5.3 statistical software. The software was used to perform statistical analysis on joint function, revision, prosthesis fracture, abnormal joint noise, and prosthesis wear rate after CoC or CoP.@*RESULTS@#Seven RCTs studies were included, including 390 cases of hips with CoC artificial joints and 384 cases of hips with CoP artificial joints. The long-term joint function improvement of CoC and CoP artificial joints was similar and there was no significant differences, with an average difference was MD=0.63, 95%CI=(-1.81, 3.07), P=0.61. About the postoperative complications, CoC artificial joints have higher incidence rate of abnormal joint noise, with odds ratio (OR)=11.05, 95%CI=(2.04, 59.84), P=0.005. CoP artificial joints wear faster, with an average MD=-87.11, 95%CI=(-114.40, -59.82), P<0.000 1. There was no significant difference between the two groups in the replacement-related complications such as joint dislocation, prosthesis loosening, osteolysis, and the rate of prosthesis revision caused by various reasons.@*CONCLUSION@#The clinical function results and complications of CoC artificial joints are comparable to those of CoP artificial joints. Although CoP artificial joint prosthesis has a faster wear rate, it does not affect joint function and increase complications, and there is no abnormal joint noise. CoC is expensive and the long-term efficacy is equivalent to CoP. Clinicians should consider cost performance when choosing CoC.

Polyethylene glycol combined with lactulose has better efficacy than polyethylene glycol alone in bowel preparation before colonoscopy: A meta-analysis

Abstract Background: The accuracy of diagnosis and the safety of treatment in colonoscopy depends largely on the quality of bowel cleansing. This study aimed to compare the efficacy and adverse reactions of Polyethylene Glycol (PEG) combined with lactulose with that of PEG alone in bowel preparation before colonoscopy. Methods: The authors searched a number of databases including EMBASE, MEDLINE, Cochrane Library, and China Academic Journals Full-text Database. The authors screened according to literature inclusion and exclusion criteria, assessed the quality of the included literature, and extracted the data. The meta-analysis of included literature used RevMan 5.3 and Stata 14.0 software. Results: A total of 18 studies, including 2274 patients, were enrolled. The meta-analysis showed that PEG combined with lactulose had a better efficacy (OR = 3.87, 95% CI 3.07‒4.87, p = 0.000, and I2 = 36.2% in the efficiency group; WMD = 0.86, 95% CI 0.69‒1.03, p = 0.032 and I2 = 0% in the BBPS score group) in bowel preparation for patients with or without constipation. Moreover, PEG combined with lactulose had fewer adverse reactions, including abdominal pain (OR = 1.42, 95% CI 0.94‒2.14, p = 0.094), nausea (OR = 1.60, 95% CI 1.13‒2.28, p = 0.009) and vomiting (OR = 1.77, 95% CI 1.14‒2.74, p = 0.011), than PEG alone. No significant reduction in the incidence of abdominal distention was observed. Conclusion: PEG combined with lactulose may be a better choice for bowel preparation before colonoscopy compared with PEG alone.

Migração de partícula alergênica através de embalagem pet / Migration of allergen particles through pet

Para garantia da segurança dos consumidores muitas decisões na indústria alimentícia são tomadas com "margem de segurança", uma delas é a dispersão de partículas alergênicas em contaminações cruzadas. Em estoques de bebidas embaladas, diversas unidades que não possuem ingredientes alergênicos ou traços são descartadas quando um produto alergênico entra em contato, mesmo que pela parte externa. O presente estudo teve como objetivo avaliar se a partícula alergênica externa migra pela embalagem de PET e contamina a bebida não alergênico. Para isso, um produto em embalagem PET sem ingredientes ou partículas alergênicas (água) teve sua parte externa exposta a um ingrediente alergênico (soja) em meio aquoso e oleoso por 1, 24, 48 e 72 horas, demonstrando que não há migração para a parte interna.

To ensure the safety of consumers, many decisions in the food industry are made with "margin of safety", one is the dispersion of allergenic particles in cross-contamination. In stocks of packaged beverages, several units that do not contain allergenic ingredients or traces are discarded when an allergenic product comes into contact, even out of pack. The objective of this study is to evaluate whether the external allergenic particle migrates through the PET packaging and contaminates the non-allergenic food. A product in PET packaging without allergenic ingredients or particles (water) has your external part exposed to an allergenic ingredient (soy) in an aqueous and oily medium for 1, 24, 48 and 72 hours, and tested if are migration.

Clinical Evaluation of Composite Restorations with and without Polyethylene Fiber in First Permanent Molars: A 24-Month Randomized Clinical Trial

ABSTRACT Objective: To evaluate the 24-month clinical performance of composite resin restorations with and without polyethylene fiber in the first permanent molars of pediatric patients with extensive caries. Material and Methods: In total, 75 Class II restorations were placed in the permanent molar teeth of 75 children (mean age 11.3 years) with (FC; n=38) or without (C; n=37) fiber. One operator placed all the restorations. The restorations were evaluated using the modified USPHS criteria in terms of retention, color match, marginal discoloration, anatomic form, marginal adaptation, secondary caries, and postoperative sensitivity. Statistical data were analyzed using chi-square and Cochran tests (p<0.05). Results: At the end of two years, 65 restorations (FC:31; C:34) were followed up. No changes were observed during the first six months. After 24 months of follow-up, there were minor changes in marginal adaptation and marginal color in both groups; however, no statistically significant difference was observed between the clinical performances for all criteria (p>0.05). Conclusion: Extensive composite restorations with or without fibers displayed good clinical performance in high load-bearing areas after 24 months.

Consensus on clinical diagnosis, treatment, and prevention of chemotherapy-induced neutropenia in China (2023 edition) / 中华肿瘤杂志

Chemotherapy-induced neutropenia (CIN) is a common hematological adverse events and dose-limiting toxicities of chemotherapy. CIN may lead to dose reduction and delay of chemotherapeutic agents, febrile neutropenia and severe infection, which results in increased treatment cost, reduced efficacy of chemotherapy, and even life-threatening morbidities. Assessment of risk of CIN, early detection of FN and infection, and proper prevention and treatment play a crucial role in reducing the occurrence of CIN-related morbidities, improving patient treatment safety and anticancer efficacy. Based on evidence and expert opinion, the expert committee of Chinese Anti-Cancer Association issued "the consensus on diagnosis and treatment of chemotherapy-induced neutropenia in China (2023 edition)", which is an update version of the 2019 edition, aiming to provide reference for the diagnosis and treatment of CIN for Chinese oncologists.

Application status and views of common bowel cleansing regimens in China / 西安交通大学学报(医学版)

The quality of colonoscopy diagnosis and treatment is closely related to bowel cleansing. At present, polyethylene glycol electrolyte powder is the most widely used bowel cleaning regimen at home and abroad, but its intake is large, which reduces the compliance of patients. In recent years, many reports on the application of new bowel cleansing have emerged abroad. In contrast, the application of bowel cleanser in China is still relatively single, which has large room for improvement. At present, we need to solve the problem of developing a new bowel cleanser suitable for Chinese people to improve patient tolerance and bowel cleaning effect.

Clinical and patient reported outcomes of Vitamin E diffused highly cross-linked polyethylene liner versus moderately cross linked polyethylene liner in total hip arthroplasty: A meta-analysis

Introduction@#In the modern era of Medicine, total hip arthroplasty (THA) is found to last longer than ever before due to the fact that there has been improved bearing surfaces and materials available. Despite these modern approaches, failure caused by polyethylene wear, aseptic loosening, instability and mispositioning and even infection could affect THA survival. In the course of addressing anti-wear characteristics of the conventional polyethylene surface various approaches have been made. To date, there are very limited studies done in which polyethylene liner is better.@*General Objective@#To compare the effects of vitamin E diffused highly cross-linked polyethylene liner versus moderately cross-linked polyethylene liner in THA. @*Methodology@#Meta-analysis research design was used in this study. The primary investigators conducted a comprehensive literature search from Medline, Cochrane Library, PubMed, Elsevier, Google Scholar, Embase and ClinicalTrial.gov as electronic database. All randomized controlled trials comparing the effects of vitamin E diffused highly cross-linked polyethylene liner versus moderately cross-linked polyethylene liner in THA were included in the review. @*Conclusions@#The investigation disclosed no statistical significance between moderately cross-linked polyethylene liner and vitamin E diffused highly cross-linked polyethylene liner in terms of migration, head penetration and wear on mediolateral, longitudinal and anteroposterior axes after 2 and 5 years of undergoing THA. Moreover, the data pertaining to patient reported outcomes and clinical outcomes measure also indicated no statistical significance between moderately cross-linked polyethylene liner and vitamin E diffused highly cross-linked polyethylene liner. This indicates that vitamin E diffused highly cross-linked polyethylene liner is comparable with the conventional moderately cross-linked polyethylene liner. Vitamin E-infused highly cross-linked polyethylene ( VEPE) showed an almost similar stability with regard to the wear rates and the component showed similar stability with that of moderately cross-linked polyethylene liner.

Effects of Charcoal Preservation Methods on the Biochemical Parameters of Three Varieties of Plantain (Musa ssp)

Aims: To contribute to solving plantain post-harvest losses, six preservation methods combining charcoal and polyethylene bags were experimented on three different varieties of plantain (SACI, Big-Ebanga, and Orishele). Place and Duration of Study: This work was carried out at the Biocatalysis and Bioprocesses Laboratory of Nangui Abrogoua University in Abidjan and the Food Technology Laboratory of the National Center for Agronomic Research in Côte d'Ivoire. Methodology: Some Biochemical parameters of these fruits are monitored to know the effects of these preservation methods during storage. Results: The outcomes indicate an average shelf green life extension of up to 30 days for fruits preserved in polyethylene containing charcoal, while fruits preserved in polyethylene without charcoal have only 24 days on average. The control test (fruits stored in the open air) showed an average shelf green life of 12 days. During storage, total carbohydrate levels increase and values range from 92.49% to 70.05%. Those of total sugars also increase and the levels evolve from 0.47 to 30.83 g/100 g DM. On the other hand, there is a decrease in starch levels (42.66 and 64.05 mg/100g DM). Conclusion: Charcoal can extend the shelf green life of plantain bananas for up to a month. These methods can be recommended to actors in the sector to reduce post-harvest losses.

Uso del polietileno poroso de alta densidad como alternativa en reconstrucción de fracturas orbitarias. Serie de 22 casos / Use of high-density porous polyethylene as an alternative in orbital fracture reconstruction. 22 Case series

Introducción: las fracturas de pared de órbita pueden producir secuelas funcionales y estéticas. La indicación de reconstrucción quirúrgica, es indispensable para la recuperación de la motilidad y estética ocular. Los materiales reconstructivos más utilizados son los aloplásticos, como el titanio y el polietileno poroso de alta densidad (PPAD), el cual ha resultado exitoso en reconstrucción maxilofacial. El propósito de este estudio retrospectivo, es exponer los resultados tras el uso del PPAD en reconstrucciones orbitarias y sus posibles complicaciones. Materiales y métodos: se realizó una revisión retrospectiva de 22 pacientes donde se utilizó PPAD como material de reconstrucción en fracturas orbitarias. Se consideró para la indicación quirúrgica que el paciente presentara alguno de los siguientes signos: diplopía o síntomas vasovagales por atrapamiento muscular, restricciones en la motilidad ocular, enoftalmo mayor a 4mm. El material utilizado fue PPAD (Medpor Stryker®) puro en 17 casos y PPAD reforzado con una malla de titanio en el interior de su estructura (Medpor Titan Stryker®), en los 5 restantes. Resultados: se registraron 3 casos con complicaciones; ectropión, diplopía y ectropión con diplopía, los cuales todos fueron reversibles. No se registraron casos de infección ni complicaciones oftalmológicas postoperatoria. Discusión: los injertos autólogos fueron los primeros utilizados con resultados de compatibilidad y resistencia óptimos. El uso de PPAD como material de reconstrucción ha sido bien documentado con buenos resultados en términos de una baja incidencia de infección y óptima motilidad ocular a largo plazo.

Introduction: Orbital wall fractures can cause functional and aesthetic sequelae. When there is an indication for surgical reconstruction, this is essential for the recovery of ocular motility and aesthetics. The most commonly used reconstructive materials are alloplastics, such as titanium and porous high-density polyethylene (PPAD), which have been successful in maxillofacial reconstruction. The purpose of this retrospective study is to present the results and their possible complications in orbital reconstruction with PPAD. Materials and methods: a retrospective review of 22 patients in whom PPAD was used as reconstruction material for orbital fractures was performed. It was considered for the surgical indication that the patient presented any of the following signs: diplopia or vasovagal symptoms due to muscle entrapment, ocular motility restrictions, enophthalmos greater than 4mm. The material used was pure PPAD (Medpor Stryker®) in 17 cases, and PPAD reinforced with a titanium mesh inside its structure (Medpor Titan Stryker®), in the remaining 5. Results: 3 patients with complications were registered; ectropion, diplopia, and ectropion with diplopia, all of which were reversible. There were no cases of postoperative infection or ophthalmological complications. Discussion: Autologous grafts were the first used with optimal compatibility and resistance results. The use of PPAD as a reconstruction material has been well documented with good results in terms of a low incidence of infection and optimal long-term ocular motility

Feasibility of corneal epithelial transplantation with polyethylene glycol hydrogel membrane as a carrier for limbal stem cell deficiency / 中华实验眼科杂志

Objective:To investigate whether polyethylene glycol hydrogel films (PHFs) can be used as a carrier for the expansion of corneal epithelial cells (CECs) in vitro and whether PHFs can be used in the treatment of limbal stem cell deficiency (LSCD). Methods:Sebacoyl chloride, dihydroxyl PCL and glycerol ethoxylate were used to synthesize PHFs.The thickness, transmittance and mechanical tensile properties of PHFs were measured.Four clean-grade New Zealand white rabbits were selected to culture primary limbal epithelial cells.The expression of keratin marker AE1/AE3 and stem cell marker p63 in the cultured cells were observed under a fluorescence microscope.The cells were divided into negative control group cultured with common cell culture solution, positive control group cultured with cell culture solution containing 100 μmol/L H 2O 2, and PHFs+ CECs group lined with PHFs cultured with common cell culture solution for 24 hours.The proliferation and apoptosis of cells in the three groups were observed by MTT and TUNEL staining, respectively.Fifteen clean-grade New Zealand white rabbits were divided into control group, PHFs group and PHFs+ CECs group by random number table method, with 5 rabbits in each group.LSCD model was constructed in the three groups.The control group was not given any treatment after modeling.In PHFs group, empty PHFs were placed on the corneal surface of rabbits.In PHFs+ CECs group, tissue-engineered grafts constructed with CECs after passage implanted on PHFs were placed on the corneal surface of rabbits.The corneal defect area of rabbits was detected and scored by fluorescein sodium staining.The histological characteristics of rabbits corneal epithelium was observed by hematoxylin-eosin staining.The use and care of animals complied with Guide for the Care and Use of Laboratory Animals by the U. S.National Research Council.The experimental protocol was approved by the Research and Clinical Trial Ethics Committee of The First Affiliated Hospital of Harbin Medical University (No.2021006). Results:The synthetic PHFs were with a thickness ≤150 μm, a tensile strength about 6 MPa, and a transmittance over than 99% in the range of 400-700 nm.Most of the cells from primary culture of limbal tissue were positive for AE1/AE3 and p63.MTT test results showed that the A490 value of PHFs+ CECs group, negative control group and positive control group was 0.59±0.01, 0.65±0.07 and 0.06±0.04, respectively, showing a statistically significant overall difference ( F=12.25, P<0.05). The A490 values of PHFs+ CECs group and negative control group were significantly higher than that of positive control group, and the differences were statistically significant (both at P<0.05). TUNEL test results showed that there was a significant difference in the TUNEL-positive cell rate among the three groups ( F=13.45, P<0.05), and the rates of TUNEL-positive cells in PHFs+ CECs group and negative control group were significantly lower than that in positive control group (both at P<0.05). Fluorescein sodium staining results showed that with the extension of postoperative period, the corneal fluorescein sodium staining score of the three groups decreased, which decreased successively in control group, PHFs group and PHFs+ CECs group.Hematoxylin-eosin staining showed fewer irregularly shaped corneal epithelial cells in the control group, and sparse single layer of corneal epithelial cells in some areas of the PHFs group.In PHFs+ CECs group, the corneal epithelium coverage was the largest, and the cell layers increased to 3-5, and the cells were with regular morphology and in close arrangement. Conclusions:PHFs have enough toughness, high transmittance and can expand corneal epithelium in vitro.PHFs are suitable for corneal epithelial transplantation and can promote the repair of corneal epithelium in rabbit model of LSCD.

Embryotoxic and teratogenic effects of polyethylene microbeads using the zebrafish Danio rerio (Hamilton, 1822)

Background@#The escape of polyethylene microbeads from waste-water treatment facilities to aquatic habitats has been a major concern by scientific communities due to the adverse effects on aquatic organisms as well as the well-being of the marine and terrestrial ecosystems. @*Objective@#This study was conducted to evaluate the embryotoxic and teratogenic effects of polyethylene microbeads on the early development of the zebrafish Danio rerio using the Fish Embryo Acute Toxicity Test (FET). @*Methodology@#Sixty (60) zebrafish embryos were exposed to polyethylene microbead suspensions (PE-MBS) of 20 μg/L, 200 μg/L, and 2000 μg/L concentrations. Using FET, the toxicological endpoints (i.e., egg coagulation, lack of somite formation, non-detachment of tail, and lack of heartbeat) were observed every 24 hours until the 96th-hour exposure. Hatching of the embryo from the chorion was observed from 48-96 hpf (hours-post fertilization), and at least four parameters of teratogenicity (i.e., edema of the pericardium and yolk sac, bent axis, tail curvature, and collapsed swim bladder) was observed at 144 hpf. @*Results@#Significant differences between means and variances in the embryotoxic and teratogenic effects were observed for all treatment groups in relation to the negative control (reconstituted water). The emulsifier control (0.01% Tween 80, p-value=0.9), the solvent control (1% DMSO, p-value = 0.9), and the 20 μg/L PE-MBS (p-value = 0.92) did not significantly differ with the negative control group. However, the positive control (5% ethanol, pvalue= 7.8) and 200 μg/L (p-value = 1.1), and 2000 μg/L (p-value = 1.48) of PE-MBS were significantly embryotoxic and teratogenic to the developing organism. @*Conclusion@#The high concentrations of PE-MBS (200 μg/L and 2000 μg/L) may induce early hatching, mortality, and malformations. Tukey Kramer post hoc test substantiated that PE-MBS toxicity is dose-dependent since embryotoxicity and teratogenicity increase at higher concentrations. Further studies should be conducted to know more about the adverse effects of polyethylene microbeads on the development, physiology, and genomics of freshwater fishes.