Fibrovascular ingrowth into porous polyethylene orbital implants (Medpor) after modified evisceration.

PURPOSE: To evaluate, using MRI, the extent and pattern of fibrovascular ingrowth into Medpor implants after modified evisceration. METHODS: Contrast T1-weighted images were performed in 21 patients within 1.5- to69-month intervals after modified evisceration with primary Medpor implantation. In 6 patients, the images were obtained separately following 1- and 5-minute delays after contrast administration. RESULTS: No grade I enhancement occurred in these series. Grade II was observed in 2 patients (9.09%), grade III in 8 patients (36.36%), grade IV in 9 patients (40.91%), and grade V in 3 patients (13.64%). Significant correlation existed between the grade of enhancement and the postevisceration interval (r = 0.483, p = 0.023 < 0.05). The images demonstrated an enhancement pattern that started at the unwrapped posterior pole and anterior location of rectus muscles with progressive centripetal vascularization toward the center of the implant. At the early stage of recovery, the fibrous connective tissue was thick in front of Medpor spheres. In the 5-minute delay images of 6 patients, 2 patients failed to exhibit further enhancement; 2 patients exhibited enlarged and homogeneous enhancement; and 2 patients revealed more intense enhancement patterns. The medical ethics committee of Zhongshan Ophthalmic Center approved the study. CONCLUSIONS: Fibrovascular ingrowth into Medpor implants was satisfactory after the modified evisceration and correlated with the duration of the implants. The double layers of sclera effectively prevented the implant extrusion and exposure. The authors recommend waiting at least 5 minutes before obtaining MR images after contrast administration.

A SERS-active microfluidic device with tunable surface plasmon resonances.

A surface-enhanced Raman scattering (SERS)-active microfluidic device with tunable surface plasmon resonances is presented here. It is constructed by silver grating substrates prepared by two-beam laser interference of photoresists and subsequent metal evaporation coating, as well as PDMS microchannel derived from soft lithography. By varying the period of gratings from 200 to 550 nm, surface plasmon resonances (SPRs) from the metal gratings could be tuned in a certain range. When the SPRs match with the Raman excitation line, the highest enhancement factor of 2×10(7) is achieved in the SERS detection. The SERS-active microchannel with tunable SPRs exhibits both high enhancement factor and reproducibility of SERS signals, and thus holds great promise for applications of on-chip SERS detection.

Biomimetic Asymmetric Polymer Brush Coatings Bearing Fencelike Conformation Exhibit Superior Protection and Antifouling Performance.

Antifouling surfaces with optimized conformation and compositional heterogeneities are presented with the goal of improving the efficacy of surface protection. The approach exploits the adhesive group (thiol or catechol chain end) to anchor asymmetric polymer brushes (APBs) bearing amphiphilic side chains with synergistic nonfouling and fouling-release abilities onto the surface. The conformation of the APB surface is close to the fencelike structure, which mimics lubricating protein lubricin, endowing the surface with capacity of enhanced protection and antiadhesivity, even facing the high compression of fouling. By utilizing a poly(Br-acrylate-alkyne) macroagent comprising alkynyl and 2-bromopropionate groups, we prepared a series of APB surfaces based on polyacrylate-g-poly(ethylene oxide)/poly(pentafluorophenyl methacrylate) (PA-g-PEO/PPFMA) APBs to explore the influence of the content of the fluorinated segment and bioinspired topological polymer chemistry on their antifouling performance. The APB surfaces can not only provide compositional heterogeneities of PEO and fluorinated segments in each side chain but also give a high surface coverage because of the characteristic of high grafting density of macromolecular brushes. It was found for the first time, as far as we are aware, the fencelike APB surface shows excellent antifouling performance with less protein adsorption (up to 91% off) and cell adhesion (up to 84% off) in comparison with the controlled substrate under relatively long incubation time.

Comparison of two types of catheters through femoral vein catheterization in patients with lung cancer undergoing chemotherapy: A retrospective study.

PURPOSE:: This study aimed to investigate the effects and complications of different types of peripherally inserted central catheters through femoral vein catheterization in patients with lung cancer undergoing chemotherapy. METHODS:: A retrospective analysis of 158 patients with lung cancer undergoing implantation of a venous access through femoral vein catheterization was performed. The patients were divided into two groups by convenience sampling: the single-lumen silicone Groshong peripherally inserted central catheters with valved tip were used in patients in group A, the single-lumen power-injectable polyurethane peripherally inserted central catheters with no valve were used in patients in group B. The gravity flow rate and indwelling time of the catheter and incidences of total obstruction, transient obstruction, irreversible obstruction, catheter-related thrombosis, catheter breakage, and accidental dislodgment were compared between the two groups. RESULTS:: The catheter indwelling time and incidences of irreversible obstruction, catheter-related thrombosis, and accidental dislodgment in the two groups were not statistically significantly different ( p > 0.05). The catheter gravity flow rate and incidences of total obstruction, transient obstruction, and catheter breakage were statistically significantly different between the two groups ( p < 0.01). CONCLUSION:: Single-lumen power-injectable peripherally inserted central catheters with no valve had a high gravity flow rate, were strong and not prone to rupture, tolerant to high-pressure injection, and were more suitable for femorally inserted central venous catheterization in patients with lung cancer undergoing chemotherapy.

Spin-Casting Polymer Brush Films for Stimuli-Responsive and Anti-Fouling Surfaces.

Surfaces modified with amphiphilic polymers can dynamically alter their physicochemical properties in response to changes of their environmental conditions; meanwhile, amphiphilic polymer coatings with molecular hydrophilic and hydrophobic patches, which can mitigate biofouling effectively, are being actively explored as advanced coatings for antifouling materials. Herein, a series of well-defined amphiphilic asymmetric polymer brushes containing hetero side chains, hydrophobic polystyrene (PS) and hydrophilic poly(ethylene glycol) (PEG), was employed to prepare uniform thin films by spin-casting. The properties of these films were investigated by water contact angle, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and quartz crystal microbalance (QCM). AFM showed smooth surfaces for all films with the roughness less than 2 nm. The changes in water contact angle and C/O ratio (XPS) evidenced the enrichment of PEG or PS chains at film surface after exposed to selective solvents, indicative of stimuli- responsiveness. The adsorption of proteins on PEG functionalized surface was quantified by QCM and the results verified that amphiphilic polymer brush films bearing PEG chains could lower or eliminate protein-material interactions and resist to protein adsorption. Cell adhesion experiments were performed by using HaCaT cells and it was found that polymer brush films possess good antifouling ability.

Preparation and characterization of Lignin-graft-poly (ɛ-caprolactone) copolymers based on lignocellulosic butanol residue.

In this paper, a "graft from" Ring-Opening Polymerization (ROP) technique was used to synthesize a lignin-graft-poly (ɛ-caprolactone) copolymer (BBL-g-PCL) using biobutanol lignin (BBL) as raw material recovered from lignocellulosic butanol residue. Polymerizations were carried out with various mass ratios of BBL and CL monomer ([BBL]/([BBL]+[CL])=1.0%, 5.0%, 10%, 20% and 40% (w/w)) to obtain BBL-g-PCL copolymers with different molecular weights, ranging from 367 to 8163gmol(-1). The grafting efficiency was preliminary evidenced by the long-term stability of dissolution of BBL-g-PCL in toluene. FT-IR and NMR analysis provided the further evidences for successful formation of BBL-g-PCL copolymer. The thermal properties of BBL-g-PCL copolymers were characterized by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). These results indicated that BBL-g-PCL copolymer had relatively good thermal stability. The static contact angle of BBL-g-PCL coating film reached to 80°. The surface functional groups and chemical composition of BBL-g-PCL copolymer was investigated in detail by X-ray photoelectron spectroscopy (XPS). The surface morphology of BBL-g-PCL copolymer was studied by Atomic force microscopy (AFM). Additionally, BBL-g-PCL coating film exhibited high absorption in the ultraviolet (UV) range, which could allow for applications in UV-blocking coatings, as well as the extents for the utilization of lignocellulosic butanol residue.