Juan Ye

Simultaneous mechanical property and biodegradation improvement of wollastonite bioceramic through magnesium dilute doping.

The large-area bone defects in head (including calvarial, orbital, and maxillofacial bone) and segmental bone are attracting increased attention in a wide range of clinical departments. A key requirement for the clinical success of the bioactive ceramics is the match of the mechanical behavior of the implants with the specific bone tissue to be filled. This raises the question as to what design strategy might be the best indicators for the balance between mechanical properties and biological performances. Here we go beyond the traditional approaches that use phase conversion or biphasic hybrid; instead, we achieved a simultaneous enhancement of several mechanical parameters and optimalization of biodegradability by using a dilute doping of Mg in a single-phase wollastonite bioceramic. We show that the wollastonite ceramic can be rationally tuned in phase (α or β), mechanical strength (in compression and bending mode), elastic modulus (18-23GPa), and fracture toughness (>3.2MPam(1/2)) through the usage of Mg dopant introduced at precisely defined dilute concentrations (Mg/Ca molar ratio: 1.2-2.1%). Meanwhile, the dilute Mg-doped wollastonite ceramics are shown to exhibit good bioactivity in vitro in SBF but biodegradation in Tris is inversely proportional to Mg content. Consequently, such new highly bioactive ceramics with appreciable strength and toughness are promising for making specific porous scaffolds for enhancing large segmental bone defect and thin-wall bone defect repair.

Chitosan-modified, collagen-based biomimetic nanofibrous membranes as selective cell adhering wound dressings in the treatment of chemically burned corneas

Corneal chemical injury is a general but intractable ocular emergency, the sequelae of which are particularly challenging to treat. Human amniotic membrane (HAM) is one of the resources as a wound dressing for damaged corneal reconstruction, but the concerns related to the possible transmission of infectious diseases are the main drawbacks. Here we present a versatile method utilizing electrospinning and surface modification processes to develop optically highly transparent, microstructurally stable (>20 MPa in tensile strength in the wet state) biomimetic nanofibrous membranes. These membrane nanofibers, mainly consisting of a collagen-hyaluronate interior and a chitosan surface coating, showed superior mechanical and biological performances compared to HAM, and were favorable to the selective adhesion of epithelial cells (corneal, conjunctival) and fibroblasts. The alkali-burned corneal damage model in rats demonstrated that the biomimetic membranes could markedly improve re-epithelialization in corneal tissue within one week. Therefore, such bioactive multifunctional membranes may find widespread biomedical applications in wound healing and postoperative anti-adhesion in the near future.

Association between dietary carbohydrate intake and dietary glycemic index and risk of age-related cataract: A meta-analysis

PURPOSE To assess the association of dietary carbohydrate intake and dietary glycemic index (GI), and risk of age-related cataract (ARC), and quantitatively estimate their dose-response relationships. METHODS We searched Medline, the Cochrane Library, Excerpta Medica database (EMBASE), Institute for Scientific Information (ISI) Science Citation Index, ISI Web of Knowledge, and China National Knowledge Infrastructure (CNKI) databases before October 2013. Two authors independently extracted data and assessed study quality. The random-effect model was used to calculate the pooled odds ratios (ORs). Dose-response analyses, subgroup analyses based on ARC subtypes, heterogeneity, and publication bias assessment were also carried out. RESULTS Seven studies were included in our meta-analysis. The pooled ORs of ARC for the highest versus the lowest category of carbohydrate intake and GI were 1.18 (95% confidence interval [CI]: 1.01-1.38) and 1.15 (95% CI: 1.00-1.32), respectively. Further subgroup analyses based on ARC subtypes suggested a marginally significant association between higher carbohydrate intake and cortical cataract risk (OR: 1.37, 95% CI: 0.99-1.90), and a statistically significant association between higher GI and nuclear cataract risk (OR: 1.23, 95% CI: 1.03-1.46). In addition, a significant dose-response relationship was observed between carbohydrate intake and the risk of cortical cataract. CONCLUSIONS Our results indicate that higher dietary carbohydrate quantity and GI may be associated with the risk of cortical and nuclear cataract, respectively. The results should be interpreted cautiously and more studies are warranted to clarify this issue.

A primary study of poly(propylene fumarate)–2-hydroxyethyl methacrylate copolymer scaffolds for tarsal plate repair and reconstruction in rabbit eyelids

Eyelid reconstruction includes anterior lamella reconstruction and posterior lamella reconstruction. As an important skeletal component of the posterior lamella, tarsal plates repair is the key issue for eyelid reconstruction. Presently, neither traditional surgery nor autograft/allograft has achieved satisfactory repair effects. Poly(propylene fumarate)-co-2-hydroxyethyl methacrylate (PPF-HEMA) networks with mass ratios of 1 : 0.5, 1 : 1 and 1 : 2 were synthesized and used as the tarsal substitute in this study. Their chemical compositions, swelling ability, and mechanical properties were characterized. Porous scaffolds were fabricated by a gelatin particle leaching method. The in vitro studies of cytotoxicity on human dermal fibroblasts (HDFs) and degradation demonstrated that PPF-HEMA scaffolds did not have noticeable cell cytotoxicity and their degradation rates correlated with the ratio of PPF to HEMA. The PPF-HEMA networks, with mass ratios of 1 : 1 and 1 : 2, and an ADM control were implanted in rabbits with tarsal plate defects for in vivo biocompatibility and degradation behavior evaluation. PPF-HEMA scaffolds provided satisfactory repair results with mild tissue response and biocompatibility to fibroblast growth and fibrous capsulation compared to the ADM control. The tissue compatible and biodegradable PPF-HEMA networks with elastic mechanical properties were proven to be a suitable candidate for tarsal repair.

Global Patterns in Health Burden of Uncorrected Refractive Error

Purpose To evaluate the global patterns in health burden of uncorrected refractive error (URE) by year, age and sex, region, and socioeconomic status, using disability-adjusted life years (DALYs). Methods Global, regional, or national DALY numbers, crude DALY rates, and age-standardized DALY rates caused by URE, by year, or age and sex, were obtained from the Global Burden of Disease Study 2013. Human development index (HDI) in 2013 as a national socioeconomic indicator was obtained from the Human Development Report. Kruskal-Wallis test and linear regression were performed to explore the association between age-standardized DALY rates and HDI. Results From 1990 to 2013, global DALY numbers caused by URE rose by 43.8%, crude rates remained relatively constant, and age-standardized rates fell by 8.8%. Global DALY rates increased with age, and older females had higher DALY numbers and rates than males of the same age. Age-standardized DALY rates in Eastern Mediterranean, South-East Asia, and Africa were higher than that at a global level. Multiple comparisons indicated higher age-standardized DALY rates in lower HDI countries. Age-standardized DALY rates were inversely related to HDI (standardized β = -0.616, P < 0.001). Conclusions The global health of URE is improving but crude DALY rates are keeping constant, implying that health progress does not mean fewer demands of refractive services. Worldwide, older age, female sex, and lower socioeconomic status are associated with higher URE burden. The findings of this study may raise public awareness of the global URE burden and are important for health policy making.

Biochemically active hydrosol as a means of collecting electrospun microcapsules for drug delivery

The electrospun bead-rich nanofibers are collected by biochemically active counterionic hydrosol; thus the core–shell structured microcapsules are fabricated with a positively-to-negatively charged shell. This novel one-step method of generating microcapsules can be applied to a variety of drug-delivery formulations only by filtering, diluting, or concentrating the hydrosol.

Exposure rate of unwrapped hydroxyapatite orbital implants in enucleation surgery

Objective To document the long-term exposure rate of unwrapped coralline hydroxyapatite (HA) orbital implants and explore possible risk factors. Design This retrospective case series (May 2008–April 2013) reviewed the 234 patients with anophthalmia who underwent insertion of an unwrapped HA orbital implant by one of two different surgical closing techniques. Results Of the 234 cases, 151 underwent a rectus end-to-end suturing closure technique and 83 underwent a rectus orthotopic suturing closure technique. The time of follow-up ranged from 25 months to 69 months (mean 41.9 months). Implant exposure developed in 11 cases. Three in the rectus end-to-end suturing closure group (2.0%) and eight in the rectus orthotopic suturing closure group (9.6%). In the rectus end-to-end suturing technique, a crosswise fixation of vascularised rectus muscle tissue is formed across the front of the implant; in this group the incidence of implant exposure was reduced (OR=8.11, p=0.013). Prior ocular surgery was found to be a factor increasing the incidence of HA exposure (OR=2.73, p=0.032). Conclusions The placement of an unwrapped HA orbital implant with rectus end-to-end suturing in enucleation surgery was associated with a low rate of exposure in most cases. The end-to-end suturing creates a joint-like structure over the HA sphere, protecting the Tenons capsule and conjunctiva from its rough surface and reducing the risk of implant exposure. Prior ocular surgery may be another risk factor for HA exposure.

Regeneration of different types of tissues depends on the interplay of stem cells-laden constructs and microenvironments in vivo

The ability of repair and regeneration of tissues or organs has been significantly improved by using biomaterials-based constructs. Our previous studies found the regeneration of both articular cartilage and subchondral bone by implantation of a poly(lactide-co-glycolide) (PLGA)/fibrin gel/bone marrow stem cells (BMSCs)/(lipofectamine/pDNA-transforming growth factor (TGF)-β1) construct in vivo, without the step of pre-induced differentiation of the laden stem cells in vitro. To substantiate the ability to regenerate multi-types of tissues by the same constructs, in this study the constructs were implanted into three types of tissues or tissue defects in vivo, including subcutaneous fascia layer, and ear cartilage and eyelid tarsal plate defects. The ear cartilage and eyelid tarsal plate defects were fully regenerated 8 w post-implantation, showing a similar morphology to the corresponding native tissues. In the neo ear cartilage, abundant chondrocytes with obvious lacunas and cartilage-specific extracellular matrices (ECMs) were found. Neo eyelid tarsal plate with mature meibomian gland acinar units was regenerated. Furthermore, expressions of the ECMs-specific genes and proteins, as well as the cell behavior modulatory factors, Sry related HMG box 9 (Sox9) and TGF-β1 were significantly up-regulated in the regenerated ear cartilages and eyelid tarsal plate than those in the subcutaneously implanted constructs, which were filled with fibrocytes, inflammatory cells, obvious vascularization and slight ECMs deposition. These results confirm firmly the ability to regenerate multi-types of tissues by a stem cells-laden construct via adapting to the microenvironments of corresponding tissues.

Incidence and risk of ptosis following ocular surgery: a systematic review and meta-analysis

ObjectiveWe conducted a systematic review and meta-analysis to evaluate the incidence and risk factors of ptosis following ocular surgery.MethodsPubMed, Embase, and Cochrane Library were searched for articles that assessed the incidence or risk factors of ptosis following ocular surgery up to October 2017. We used a fixed effects model to calculate a pooled estimate of incidence, with subgroup analyses to evaluate the effect of different variables. The relative risks (RRs) or odds ratios (ORs) and 95% confidence intervals (CIs) for all available factors were calculated using the fixed effects models.ResultsA total of 16 studies on 2856 eyes were analyzed, including 3 randomized controlled trials (RCTs) and 13 cohort studies. The overall incidence of ptosis following ocular surgery was 11.4% (95% CI 10.1–12.8%). Subgroup analyses showed that the region and the surgery type were significantly associated with the incidence of postoperative ptosis. Men were less likely to get postoperative ptosis than women (OR 0.62; 95% CI 0.43–0.89). However, age (OR 0.77; 95% CI 0.48–1.23), side (OR 1.37; 95% CI 0.84–2.25), type of anesthesia (OR 0.57; 95% CI 0.16–2.05), prior surgery (OR 1.09; 95% CI 0.64–1.83), bridle suture (OR 2.04; 95% CI 0.94–4.42), or combined surgery (OR 0.95; 95% CI 0.58–1.57) did not significantly change the risk of ptosis following ocular surgery.ConclusionMore than one in ten patients who undergo ocular surgery will develop ptosis. Different regions and surgery types may influence the occurrence of this abnormality. Female gender is a risk factor for development of postoperative ptosis.

Evaluation of Scheimpflug imaging parameters in blepharospasm and normal eyes

BackgroundTo investigate changes in corneal elevation, pachymetry, and keratometry in discriminating between normal and blepharospasm eyes, as measured by the Pentacam rotating Scheimpflug camera.MethodsThis was a prospective, cross-sectional study. A total of 47 consecutive patients with a range of blepharospasm severity and 40 age- and sex- matched healthy subjects were included, one eye of each subject was randomly chosen for data analysis. Blepharospasm severity was evaluated using the Jankovic scale and categorized as mild, moderate, or severe. Corneal parameters were measured by the Pentacam rotating Scheimpflug camera to derive corneal tomography information. Various parameters regarding keratometry, elevation at the anterior and posterior corneal surface, pachymetric data, final D value, and topometric indices from the Pentacam software were recorded, and the relationship between the blink rate and corneal parameters was analyzed. Intraclass correlation coefficients (ICCs) were assessed to evaluate the repeatability of intraobserver.ResultsIncreased topographic asymmetry was observed in moderate and severe blepharospasm. Front K1and front Km were significantly higher in cases of mild (P < 0.05), moderate (P < 0.0001), and severe (P < 0.0001) blepharospasm as compared with controls. Front K2, back K1, back K2, and back Km were significantly higher in cases of moderate (P < 0.01) and severe (P < 0.001) blepharospasm as compared with controls. For corneal topometric indices, both ISV and IVA were significantly increased in severe blepharospasm (P < 0.05). Radii minimum were significantly increased in cases of moderate and severe blepharospasm (P < 0.05).There were no differences in corneal elevation and corneal pharcymetric parameters among the four groups, except for front BFS, which was significantly different in blepharospasm groups (P < 0.05). Final D values were significantly higher in the severe blepharospasm (P < 0.01) group than that among controls. There were significant correlations between the blink rate and most corneal tomographic parameters. All parameters showed high reproducibility (ICC: 0.921–0.996) for normal and blepharospasm subjects.ConclusionsBlepharospasm may lead to a redistribution of the pressure applied by the lids over the cornea and, consequently, may result in corneal shape changes, which can be documented through corneal topography.