New Linear and Star-Shaped Thermogelling Poly([R]-3-hydroxybutyrate) Copolymers.

The synthesis of multi-arm poly([R]-3-hydroxybutyrate) (PHB)-based triblock copolymers (poly([R]-3-hydroxybutyrate)-b-poly(N-isopropylacrylamide)-b-[[poly(methyl ether methacrylate)-g-poly(ethylene glycol)]-co-[poly(methacrylate)-g-poly(propylene glycol)]], PHB-b-PNIPAAM-b-(PPEGMEMA-co-PPPGMA), and their subsequent self-assembly into thermo-responsive hydrogels is described. Atom transfer radical polymerization (ATRP) of N-isopropylacrylamide (NIPAAM) followed by poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) and poly(propylene glycol) methacrylate (PPGMA) was achieved from bromoesterified multi-arm PHB macroinitiators. The composition of the resulting copolymers was investigated by (1) H and (13) C J-MOD NMR spectroscopy as well as size-exclusion chromatography (SEC), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC).

A Perspective on the Trends and Challenges Facing Porphyrin-Based Anti-Microbial Materials.

The emergence of multidrug resistant bacterium threatens to unravel global healthcare systems, built up over centuries of medical research and development. Current antibiotics have little resistance against this onslaught as bacterium strains can quickly evolve effective defense mechanisms. Fortunately, alternative therapies exist and, at the forefront of research lays the photodynamic inhibition approach mediated by porphyrin based photosensitizers.

Biodegradable Polysaccharides for Controlled Drug Delivery.

Polysaccharides are ideal candidates for drug delivery and biomedical applications as they are easily obtained from natural sources. Furthermore, they can be subjected to a wide range of chemical and enzymatic reactions, they have biocompatible and biodegradable properties and have inherently low immunogenicity. Polysaccharides are potentially the materials of choice for the development of "smart" delivery systems, which are capable of releasing, at the appropriate time and site of action, an encapsulated drug.

Diabetic retinopathy.

Diabetic retinopathy (DR) is a common complication of diabetes mellitus and is a major cause of vision loss in middle-aged and elderly people. One-third of people with diabetes have DR. Severe stages of DR include proliferative DR, caused by the abnormal growth of new retinal blood vessels, and diabetic macular oedema, in which there is exudation and oedema in the central part of the retina.

The diagnosis and assessment of visual function in Singaporean children with electrophysiology: 10-year results.

Purpose: To study the clinical use and efficacy of electrophysiology in children.

Methods: This was a retrospective review of all children aged <16 years, who were referred to the Visual Electrophysiology Laboratory at the Singapore National Eye Center between 2003 and 2013.

Results: A total of 586 children, median age 8 years (range 0.

Recent Advances in Shape Memory Soft Materials for Biomedical Applications.

Shape memory polymers (SMPs) are smart and adaptive materials able to recover their shape through an external stimulus. This functionality, combined with the good biocompatibility of polymers, has garnered much interest for biomedical applications. In this review, we discuss the design considerations critical to the successful integration of SMPs for use in vivo.

Thermogels: In Situ Gelling Biomaterial.

In situ gel delivery systems are preferred over conventional systems due to sustained and prolonged release action of therapeutic payload onto the targeted site. Thermogel, a form of in situ gel-forming polymeric formulation, undergoes sol-gel transition after administration into the body. At room temperature, the system is an aqueous polymer solution that easily entraps therapeutic payload by mixing.

Long-term outcomes of myopic choroidal neovascularisation treated with combined ranibizumab and dexamethasone characterised by multi-modal imaging.

Aim: To characterise the long-term outcomes of myopic choroidal neovascularisation (mCNV) treated with combined ranibizumab and dexamethasone, with the use of multi-modal imaging.

Methods: A retrospective study of 20 eyes with mCNV treated with intra-vitreal ranibizumab and dexamethasone on a treat-as-needed basis were followed up for a mean period of 47 months (range 19-81 months).

Results: The mean age was 55 ± 16 years, with mean refractive error of -9.

Determinants of pupil diameters and pupil dynamics in an adult Chinese population.

Background: To investigate the determinants of pupil diameter (PD), amplitude of pupil diameter change (PD-change) and speed of pupil constriction (SPC) using video anterior segment optical coherence tomography (AS-OCT) in a population-based sample of Chinese adults.

Methods: Chinese adults aged 40 to 80 years who were free from glaucoma were consecutively recruited from the population-based Singapore Chinese Eye Study. The SPC was measured by AS-OCT videography.

Updates of pathologic myopia.

Complications from pathologic myopia are a major cause of visual impairment and blindness, especially in east Asia. The eyes with pathologic myopia may develop loss of the best-corrected vision due to various pathologies in the macula, peripheral retina and the optic nerve. Despite its importance, the definition of pathologic myopia has been inconsistent.

Safety Profile and Effects of Pulsed Methylprednisolone on Vital Signs in Thyroid Eye Disease.

Objective. To analyze changes in vital signs (heart rate (HR), systolic (SBP), and diastolic blood pressure (DBP)) during and after intravenous methylprednisolone (IVMP) and any other adverse effects. Methods.

Nonpeptidic Amphiphilic Xanthone Derivatives: Structure-Activity Relationship and Membrane-Targeting Properties.

We recently reported the bioinspired synthesis of a highly potent nonpeptidic xanthone, 2c (AM-0016), with potent antibacterial activity against MRSA. Herein, we report a thorough structure-activity relationship (SAR) analysis of a series of nonpeptidic amphiphilic xanthone derivatives in an attempt to identify more potent compounds with lower hemolytic activity and greater membrane selectivity. Forty-six amphiphilic xanthone derivatives were analyzed in this study and structurally classified into four groups based on spacer length, cationic moieties, lipophilic chains, and triarm functionalization.

Valproic acid suppresses collagen by selective regulation of Smads in conjunctival fibrosis.

Overproduction of type I collagen is associated with a wide range of fibrotic diseases as well as surgical failure such as in glaucoma filtration surgery (GFS). Its modulation is therefore of clinical importance. Valproic acid (VPA) is known to reduce collagen in a variety of tissues with unclear mechanism of action.

A Comparison of Different Operating Systems for Femtosecond Lasers in Cataract Surgery.

The introduction of femtosecond lasers is potentially a major shift in the way we approach cataract surgery. The development of increasingly sophisticated intraocular lenses (IOLs), coupled with heightened patient expectation of high quality postsurgical visual outcomes, has generated the need for a more precise, highly reproducible and standardized method to carry out cataract operations. As femtosecond laser-assisted cataract surgery (FLACS) becomes more commonplace in surgical centers, further evaluation of the potential risks and benefits needs to be established, particularly in the medium/long term effects.

A simple and non-contact optical imaging probe for evaluation of corneal diseases.

Non-contact imaging techniques are preferred in ophthalmology. Corneal disease is one of the leading causes of blindness worldwide, and a possible way of detection is by analyzing the shape and optical quality of the cornea. Here, a simple and cost-effective, non-contact optical probe system is proposed and illustrated.

Designing α-helical peptides with enhanced synergism and selectivity against Mycobacterium smegmatis: Discerning the role of hydrophobicity and helicity.

Unlabelled: Recently, we reported on a series of short amphipathic α-helical peptides, comprising the backbone sequence (LLKK)2, with the ability to kill susceptible and drug-resistant Mycobacterium tuberculosis. In this study, the effect of key physicochemical parameters including hydrophobicity and helicity of α-helical peptides on anti-mycobacterial activity and synergism with rifampicin was investigated. The most hydrophobic analogue, W(LLKK)2W, displayed low selectivity against mycobacteria while peptides with intermediate hydrophobicity were shown to be equally active, yet significantly less toxic.

Recent Progress in Using Biomaterials as Vitreous Substitutes.

Vitreous substitutes are crucial adjuncts during vitreo-retinal surgery for retinal diseases such as complicated retinal detachment, macular holes, complications of diabetic retinopathy, and ocular trauma involving posterior segment. In retinal detachment surgery, an internal tamponade agent is required to provide internal pressure for reattachment of the detached neurosensory retina. Current available options serve only as a temporary surgical adduct or short-term solution and are associated with inherent problems.

Bleb needling outcomes for failed trabeculectomy blebs in Asian eyes: a 2-year follow up.

Aim: To describe the outcomes of bleb needling in primary glaucoma in an Asian tertiary eye centre over a 2y period. To compare the success rates between primary angle-closure glaucoma (PACG) and primary open angle glaucoma (POAG). Lastly, to identify factors associated with success of bleb needling.

Effect of Intraoperative Corneal Stromal Pocket Irrigation in Small Incision Lenticule Extraction.

This study aimed at evaluating the effect of intraoperative corneal pocket irrigation in small incision lenticule extraction (SMILE) and compares it to that in femtosecond laser-assisted in situ keratomileusis (FS-LASIK). Sixteen rabbit eyes underwent a SMILE procedure, with 8 eyes having corneal pocket irrigation, while the other 8 eyes were without irrigation. Another 16 eyes underwent a FS-LASIK procedure for comparison, with 8 eyes having flap irrigation, while the other 8 eyes were without irrigation.

Polypoidal Choroidal Vasculopathy in Asians.

Age related macular degeneration (AMD) in Asians has been suggested to differ from their Western counterparts in terms of epidemiology, pathogenesis, clinical presentation and treatment. In particular, polypoidal choroidal vasculopathy (PCV) appears to be the predominant subtype of exudative AMD in Asian populations, in contrast to choroidal neovascularization secondary to AMD (CNV-AMD) in Western populations. Epidemiological data on PCV has been largely limited to hospital-based studies and there are currently no data on the incidence of PCV.

Retinal microvascular calibre and risk of diabetes mellitus: a systematic review and participant-level meta-analysis.

Aims/hypothesis: The calibre of the retinal vessels has been linked to diabetes mellitus but studies have not shown consistent results. We conducted a participant-level meta-analysis to evaluate the association between retinal arteriolar and venular calibre and diabetes.

Methods: We performed a systematic review on MEDLINE and EMBASE for articles published up to December 2014.

N-Lipidated Peptide Dimers: Effective Antibacterial Agents against Gram-Negative Pathogens through Lipopolysaccharide Permeabilization.

Treating infections caused by multidrug-resistant Gram-negative pathogens is challenging, and there is concern regarding the toxicity of the most effective antimicrobials for Gram-negative pathogens. We hypothesized that conjugating a fatty acid moiety onto a peptide dimer could maximize the interaction with lipopolysaccharide (LPS) and facilitate the permeabilization of the LPS barrier, thereby improving potency against Gram-negative pathogens. We systematically designed a series of N-lipidated peptide dimers that are active against Gram-negative bacteria, including carbapenem-resistant Enterobacteriaceae (CRE).

Intra-observer and inter-observer repeatability of ocular surface interferometer in measuring lipid layer thickness.

Background: Tear lipid morphology is important for normal tear function. Recently, there have been clinical studies using interferometry to assess lipid layer thickness (LLT). The aim of the study is to examine the repeatability of a commercially available interferometer.