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1.
Aesthetic Plast Surg ; 2024 Jul 24.
Article in English | MEDLINE | ID: mdl-39046484

ABSTRACT

OBJECTIVE: The aim of this study was to further guide the diagnosis and treatment programs for clinical facial contouring with injectable fillers by studying the facial contour parameters and proportion preferences consistent with Asian aesthetics. METHODS: A total of 89 subjects (42 males and 47 females aged 20-60 years) who met the inclusion criteria were enrolled in this study. The subjects were grouped by age, sex, and external contour attractiveness score, and the external contour aesthetic parameters and proportions of the subjects in different groups were measured and analysed. RESULTS: The upper facial breadth and lower facial breadth decreased with age, with significant differences between the 50-60-year age group and other age groups (P < 0.01). The nasomental angle showed a decreasing trend with age, with significant differences between the 40-49-year age group and the 20-29-year and 30-39-year age groups (P < 0.05). Males and females were significantly different in calva height, total head height, lower facial height, and calva height to total head height ratio (P < 0.05). With increasing age, the external contour attractiveness scores of males and females both showed decreasing trends, with significant differences between the 50-60-year age group and other age groups (P < 0.05). CONCLUSION: The calva height and the cranioauricular angle have a significant impact on external contour attractiveness. In general, temporal depression, cheek sagging, lateral cheek depression, and an ill-defined mandibular border will occur due to ageing, collagen loss, ligament laxity and sagging, and soft tissue atrophy and sagging, reducing the attractiveness of the external contour. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

2.
Aesthetic Plast Surg ; 2024 Jul 12.
Article in English | MEDLINE | ID: mdl-38995348

ABSTRACT

BACKGROUND: In Asia, the demand for cosmetic facial treatments has surged due to technological advancements, increased social acceptability, and affordability. Poly-L-lactic acid (PLLA) fillers, known for their biocompatibility and biodegradability, have emerged as a popular choice for facial contouring, yet studies specifically addressing their use in Asian populations are scarce. METHODS: This retrospective study examined 30 Chinese patients who underwent facial contouring with PLLA fillers, focusing on product composition, injection techniques, and safety measures. A comprehensive clinical evaluation was performed, including the Global Aesthetic Improvement Scale (GAIS) and Global Impression of Change Scale (GICS) for effectiveness and patient satisfaction, respectively. RESULTS: No significant difference in GAIS scores was observed between injectors and blinded evaluators over a 12-month period, indicating consistent effectiveness. Patient satisfaction remained high, with GICS scores reflecting positive outcomes. The safety profile was favorable, with no serious adverse events reported. The study highlighted the importance of anatomical knowledge to avoid complications, particularly in areas prone to blindness. CONCLUSIONS: PLLA fillers offer a safe, effective option for facial contour correction in the Asian population, achieving high patient satisfaction and maintaining results over time. The study underscores the need for tailored approaches in cosmetic procedures for Asians, considering their unique facial structures and aesthetic goals. Further research with larger, multicenter cohorts is recommended to validate these findings and explore long-term effects. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

4.
Nat Commun ; 12(1): 5926, 2021 Oct 11.
Article in English | MEDLINE | ID: mdl-34635672

ABSTRACT

Enormous enhancement of superconducting pairing temperature (Tg) to 65 K in FeSe/SrTiO3 has made it a spotlight. Despite the effort of interfacial engineering, FeSe interfaced with TiOx remains the unique case in hosting high Tg, hindering a decisive understanding on the general mechanism and ways to further improving Tg. Here we constructed a new high-Tg interface, single-layer FeSe interfaced with FeOx-terminated LaFeO3. Large superconducting gap and diamagnetic response evidence that the superconducting pairing can emerge near 80 K, highest amongst all-known interfacial superconductors. Combining various techniques, we reveal interfacial charge transfer and strong interfacial electron-phonon coupling (EPC) in FeSe/LaFeO3, showing that the cooperative pairing mechanism works beyond FeSe-TiOx. Intriguingly, the stronger interfacial EPC than that in FeSe/SrTiO3 is likely induced by the stronger interfacial bonding in FeSe/LaFeO3, and can explain the higher Tg according to recent theoretical calculations, pointing out a workable route in designing new interfaces to achieve higher Tg.

5.
Colloids Surf B Biointerfaces ; 150: 317-325, 2017 Feb 01.
Article in English | MEDLINE | ID: mdl-27810128

ABSTRACT

A novel folic acid conjugated core-shell hybrid iron oxide-zinc oxide nanoparticle was developed for applications as a photosensitier (PS) in photodynamic therapy. Photodegradation studies on methylene blue demonstrated significantly enhanced photophysical properties of the produced nano-PSs, due to the charge recombination via electron trapping by dissolved Fe3+. A time and dose dependant toxicity associated with the nano-PSs was observed upon exposure to human epithelial colorectal adenocarcinoma (Caco-2) cells in the dark. UV irradiation of the synthesised nano-PSs resulted in a significant photo-killing effect with drastic reduction in Caco-2 cell viability to as low as 6%. Reduction in viability upon exposure was due fundamentally to cellular interactions with light irradiated PSs as the influence of radiation alone was subtracted. FA conjugation further enhanced the photo-killing effect.


Subject(s)
Ferric Compounds/chemistry , Folic Acid/chemistry , Metal Nanoparticles/chemistry , Photochemotherapy/methods , Zinc Oxide/chemistry , Adsorption , Caco-2 Cells , Cell Survival , Dose-Response Relationship, Drug , Humans , Kinetics , Light , Photolysis , Spectroscopy, Fourier Transform Infrared , Ultraviolet Rays
6.
Colloids Surf B Biointerfaces ; 140: 213-222, 2016 Apr 01.
Article in English | MEDLINE | ID: mdl-26764104

ABSTRACT

Hollow silica nanoparticles of two sizes with and without a folic acid targeting ligand were synthesized. Fickian diffusion of the antitumor drug doxorubicin hydrochloride (DOX) was demonstrated by the produced nanoparticles, achieving a cumulative release of 73% and 45% for 215 nm and 430 nm particles respectively over a period of 500 h. The hollow silica nanoparticles presented a time and dose dependent toxicity, selective to human epithelial colorectal adenocarcinoma (Caco2) cells, over mouse embryonic fibroblast (3T3) cells. At 24h Caco2 cell viability was reduced to 66% using pure hollow silica at a concentration of 50 µg mL(-1), while that of 3T3 cells remained at 94% under the same conditions. The selective cytotoxicity of hollow silica nanoparticles was further enhanced by conjugation of folic acid and incorporation of DOX: at 24h and an equivalent DOX concentration of 0.5 µg mL(-1), viable Caco2 cells were reduced to 45% while 3T3 cells were reduced to 83%. Interestingly the equivalent dose of free DOX was more toxic to 3T3 than to Caco2 cells, reducing the 3T3 viability to 72% and the Caco2 viability to 80%, which is likely due to the presence of the p-glycoprotein pumps in Caco2 cells. Folic acid conjugation served to enhance the viability of both cell lines in this work. Careful optimization of the folate content should further improve the cell specificity of the hollow silica nanoparticles, thus providing a viable targeting platform for cancer therapy.


Subject(s)
Doxorubicin/pharmacology , Folic Acid/chemistry , Nanoparticles/chemistry , Silicon Dioxide/chemistry , 3T3 Cells , Animals , Antibiotics, Antineoplastic/administration & dosage , Antibiotics, Antineoplastic/chemistry , Antibiotics, Antineoplastic/pharmacology , Caco-2 Cells , Cell Survival/drug effects , Doxorubicin/administration & dosage , Doxorubicin/chemistry , Drug Carriers/chemistry , Drug Delivery Systems/methods , Humans , Magnetic Resonance Spectroscopy , Mice , Microscopy, Electron, Scanning , Molecular Structure , Nanoparticles/ultrastructure , Spectroscopy, Fourier Transform Infrared
7.
Sci Rep ; 5: 12175, 2015 Jul 08.
Article in English | MEDLINE | ID: mdl-26153550

ABSTRACT

Photodynamic therapy (PDT), wherein light sensitive non-toxic agents are locally and selectively activated using light, has emerged as an appealing alternative to traditional cancer chemotherapy. Yet to date, PDT efficacy has been mostly characterized using 2D cultures. Compared to 2D cultures, 3D sphere culture generates unique spatial distributions of nutrients and oxygen for the cells that better mimics the in-vivo conditions. Using a novel polyHEMA (non-adherent polymer) fabrication process, we developed a microfluidic sphere formation platform that can (1) generate 1,024 uniform (size variation <10%) cancer spheres within a 2 cm by 2 cm core area, (2) culture spheres for more than 2 weeks, and (3) allow the retrieval of spheres. Using the presented platform, we have successfully characterized the different responses in 2D and 3D cell culture to PDT. Furthermore, we investigated the treatment resistance effect in cancer cells induced by tumor associated fibroblasts (CAF). Although the CAFs can enhance the resistance to traditional chemotherapy agents, no significant difference in PDT was observed. The preliminary results suggest that the PDT can be an attractive alternative cancer therapy, which is less affected by the therapeutic resistance induced by cancer associated cells.


Subject(s)
Antineoplastic Agents/toxicity , Photosensitizing Agents/toxicity , Spheroids, Cellular/drug effects , Antineoplastic Agents/therapeutic use , Apoptosis/drug effects , Biocompatible Materials/chemistry , Cell Culture Techniques , Cell Line, Tumor , Cisplatin/toxicity , Drug Resistance, Neoplasm , Fibroblasts/cytology , Fibroblasts/drug effects , Fibroblasts/metabolism , Humans , Light , Microfluidic Analytical Techniques/instrumentation , Microfluidic Analytical Techniques/methods , Models, Biological , Neoplasms/drug therapy , Photochemotherapy , Photosensitizing Agents/therapeutic use , Spheroids, Cellular/cytology
8.
Colloids Surf B Biointerfaces ; 125: 197-205, 2015 Jan 01.
Article in English | MEDLINE | ID: mdl-25497292

ABSTRACT

In this paper, a novel folic acid-conjugated silica-coated titanium dioxide (TiO2-SiO2) photosensitizer was synthesized and characterized using various analytical instruments. The photosensitizer was further assessed with regards to its photoreactivity, cellular and hemocompatibility, cell internalization, and phototoxicity. Conjugating folic acid with TiO2-SiO2 has shown a significantly improved compatibility of the nanoparticles with the mouse fibroblast cells (L929) at 24 h. An improved compatibility with the human nasopharyngeal epidermoid cancer (KB) cells was also demonstrated, but to a slightly reduced degree. Enhanced cell internalization was well demonstrated in the TiO2-SiO2 folate nanoparticles. Upon exposure to UV light, TiO2-SiO2 folate nanoparticles maintained a high level photodynamic reactivity and yielded a 38-43% photo-killing of KB cells. The photo-killing effect increased with increasing dosage in the investigated concentration range of 50-100 µg ml(-1).


Subject(s)
Fibroblasts/drug effects , Folic Acid/chemistry , Nanoparticles/chemistry , Photosensitizing Agents/pharmacology , Silicon Dioxide/chemistry , Titanium/chemistry , Animals , Biological Transport , Cell Line , Fibroblasts/cytology , Fibroblasts/radiation effects , Humans , KB Cells , Mice , Nanoparticles/ultrastructure , Photochemotherapy , Photosensitizing Agents/chemical synthesis , Ultraviolet Rays
9.
Chem Mater ; 26(4): 1592-1600, 2014 Feb 25.
Article in English | MEDLINE | ID: mdl-24701030

ABSTRACT

This work is aimed at engineering photosensitizer embedded nanoparticles (NPs) that produce optimal amount of reactive oxygen species (ROS) for photodynamic therapy (PDT). A revised synthetic approach, coupled with improved analytical tools, resulted in more efficient PDT. Specifically, methylene blue (MB) conjugated polyacrylamide nanoparticles (PAA NPs), with a polyethylene glycol dimethacrylate (PEGDMA, Mn 550) cross-linker, were synthesized so as to improve the efficacy of cancer PDT. The long cross-linker chain, PEGDMA, increases the distance between the conjugated MB molecules so as to avoid self-quenching of the excited states or species, and also enhances the oxygen permeability of the NP matrix, when compared to the previously used shorter cross-linker. The overall ROS production from the MB-PEGDMA PAA NPs was evaluated using the traditional way of monitoring the oxidation rate kinetics of anthracence-9,10-dipropionic acid (ADPA). We also applied singlet oxygen sensor green (SOSG) so as to selectively derive the singlet oxygen (1O2) production rate. This analysis enabled us to investigate the ROS composition mix based on varied MB loading. To effectively obtain the correlation between the ROS productivity and the cell killing efficacy, a microfluidic chip device was employed to provide homogeneous light illumination from an LED for rapid PDT efficacy tests, enabling simultaneous multiple measurements while using only small amounts of NPs sample. This provided multiplexed, comprehensive PDT efficacy assays, leading to the determination of a near optimal loading of MB in a PAA matrix for high PDT efficacy by measuring the light-dose-dependent cell killing effects of the various MB-PEGDMA PAA NPs using C6 glioma cancer cells.

10.
Lab Chip ; 14(5): 892-901, 2014 Mar 07.
Article in English | MEDLINE | ID: mdl-24394779

ABSTRACT

We present a novel high-throughput microfluidic platform that enables the evaluation of the anticancer efficacy of photodynamic therapy (PDT) drugs over multiple microenvironmental factors. PDT is uniquely complex, originating from its dependence on three separate but essential elements: drug (also called photosensitizer), oxygen, and light. Thus, obtaining a reliable evaluation of PDT efficacy is highly challenging, requiring considerable effort and time to evaluate all three interdependent parameters. In this paper, we report a high-throughput efficacy screening platform that we implemented by developing microfluidic components that individually control basic PDT elements (photosensitizer concentrations, oxygen levels, and light fluence) and then integrating them into a single triple-layer device. The integrated microfluidic chip consists of an array of small compartments, each corresponding to a specific combination of these three variables. This allows for more than 1000 different conditions being tested in parallel. Cancer cells are cultured within the device, exposed to different PDT conditions, and then monitored for their viability using live/dead fluorescence staining. The entire screening assay takes only 1 hour, and the collected PDT outcomes (cell viability) for combinatorial screening are analysed and reported as traditional dose-response curves or 3D bubble charts using custom software. As a proof of concept, methylene blue is adopted as a photosensitizer and its drug efficacy on C6 glioma cells has been successfully evaluated for a total of 324 PDT conditions using the fabricated chip. This platform can facilitate not only the development of new photosensitizers but also the optimization of current PDT protocols.


Subject(s)
Microfluidic Analytical Techniques/methods , Oxygen/analysis , Photosensitizing Agents/analysis , Aminolevulinic Acid/analysis , Aminolevulinic Acid/therapeutic use , Aminolevulinic Acid/toxicity , Brain Neoplasms/drug therapy , Cell Line, Tumor , Cell Survival/drug effects , Glioma/drug therapy , Humans , Light , Microfluidic Analytical Techniques/instrumentation , Photochemotherapy , Photosensitizing Agents/pharmacology , Photosensitizing Agents/therapeutic use
11.
Colloids Surf B Biointerfaces ; 107: 220-6, 2013 Jul 01.
Article in English | MEDLINE | ID: mdl-23502045

ABSTRACT

Photosensitive nanoparticles are useful in developing phototherapeutic agents for targeted cancer therapy. In this paper, core-shell structured titanium dioxide-silica (TiO2-SiO2) nanoparticles, with varying shell thickness, were synthesized. The influence of the silica shell thickness on the photoreactivity, cytotoxicity and photo-killing ability of the TiO2 nanoparticles was investigated. Silica coating reduced the photocatalytic reactivity but improved the cytocompatibility of the TiO2 nanoparticles. This effect was amplified with increasing silica shell thickness. When the silica thickness was about 5.5 nm, the coated TiO2 not only retained a high level photodynamic reactivity, comparable to the non-coated TiO2 nanoparticles, but also demonstrated an improved cell compatibility and effective photo-killing ability upon the mouse fibroblast cells (L929).


Subject(s)
Coated Materials, Biocompatible/pharmacology , Nanoparticles/chemistry , Photochemotherapy , Silicon Dioxide/pharmacology , Titanium/pharmacology , Animals , Catalysis/drug effects , Catalysis/radiation effects , Cell Death/drug effects , Cell Death/radiation effects , Cell Survival/drug effects , Cell Survival/radiation effects , Fibroblasts/cytology , Fibroblasts/drug effects , Fibroblasts/radiation effects , Hemolysis/drug effects , Hemolysis/radiation effects , Hydrolysis/drug effects , Hydrolysis/radiation effects , Materials Testing , Mice , Nanoparticles/ultrastructure , Phenols/analysis , Rabbits , Spectroscopy, Fourier Transform Infrared , Ultraviolet Rays
13.
Zoolog Sci ; 28(8): 606-8, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21801002

ABSTRACT

Following FIASCO protocol and across-amplification approach, we present eleven microsatellite primers of the Oriental White stork, Ciconia boyciana in this article. All loci were polymorphic, except for locus Cbo235, which possessed two alleles but was homozygous in all 23 individuals of C. boyciana used in this study. The number of the alleles per locus ranged from two to eight, and the observed heterozygosity (H(o)) and expected heterozygosity (H(E)) ranged from 0 to 0.857 and 0.222 to 0.851, respectively. These markers are proved useful in genetic study of C. boyciana.


Subject(s)
Birds/genetics , DNA/genetics , Microsatellite Repeats/genetics , Animals
14.
Sci China Life Sci ; 54(4): 366-71, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21416229

ABSTRACT

The objective of this study was to investigate the hemocompatibility and cell responses to some novel poly(L-lactide) (PLA) composites containing surface modified hydroxyapatite particles for potential applications as a bone substitute material. The surface of hydroxyapatite (HA) particles was first grafted with L-lactic acid oligomers to form grafted HA (g-HA) particles. The g-HA particles were further blended with PLA to prepare g-HA/PLA composites. Our previous study has shown significant improvement in tensile properties of these materials due to the enhanced interfacial adhesion between the polymer matrix and HA particles. To further investigate the potential applications of these composites in bone repair and other orthopedic surgeries, a series of in vitro and in vivo experiments were conducted to examine the cell responses and hemocompatibility of the materials. In vitro experiments showed that the g-HA/PLA composites were well tolerated by the L-929 cells. Hemolysis of the composites was lower than that of pure PLA. Subcutaneous implantation demonstrated that the g-HA/PLA composites were more favorable than the control materials for soft tissue responses. The results suggested that the g-HA/PLA composites are promising and safe materials with potential applications in tissue engineering.


Subject(s)
Biocompatible Materials/chemistry , Durapatite/chemistry , Polyesters/chemistry , Polymers/chemistry , Animals , Biocompatible Materials/metabolism , Bone Substitutes/chemistry , Bone Substitutes/metabolism , Cell Adhesion , Cells, Cultured , Durapatite/metabolism , Fibroblasts/cytology , Fibroblasts/physiology , Implants, Experimental , Materials Testing , Mice , Molecular Structure , Polyesters/metabolism , Polymers/metabolism , Rabbits , Surface Properties , Tissue Engineering
16.
Chem Commun (Camb) ; 46(9): 1553-5, 2010 Mar 07.
Article in English | MEDLINE | ID: mdl-20162179

ABSTRACT

Chemoselective reduction of alpha,beta-unsaturated aldehydes in the presence of CO and H(2)O proceeds effectively over a ceria-supported gold catalyst system, providing a novel, efficient and clean approach to produce useful primary allyl alcohols with excellent activity and selectivity.


Subject(s)
Aldehydes/chemistry , Carbon Monoxide/chemistry , Gold/chemistry , Hydrogen/chemistry , Water/chemistry , Alcohols/chemistry , Catalysis , Cerium/chemistry , Hydrogenation
17.
J Mater Sci Mater Med ; 20(11): 2215-22, 2009 Nov.
Article in English | MEDLINE | ID: mdl-19517217

ABSTRACT

Many investigations have been attempted to promote calcification of synthetic polymers for applications as orthopaedic and dental implants. In this study, novel titanium dioxide (TiO(2)) reinforced porous poly(2-hydroxyethyl methacrylate) (pHEMA) hydrogels were synthesized. Calcification capacity of the composite polymers was examined using light microscopy, scanning electron microscopy and Fourier transform infrared spectroscopy after incubation of the materials in a simulated body fluid up to 53 days. Mechanical strength, porosity and in vitro cytotoxicity were also investigated. Calcification capacity of porous pHEMA was significantly enhanced by the addition of TiO(2) particulates. Infiltration of calcium phosphate, up to 1000 mum, was observed. The diffusion capacity of calcium ions was affected by the porosity and the interconnectivity of pores in the hydrogel polymers which were influenced by the presence of TiO(2) and the monomer concentration. Cell viability tests indicated that porous hydrogels containing 7.5% TiO(2) were not toxic to 3T3 fibroblast cells. These results demonstrate that incorporating TiO(2) nanoparticulates can promote enhanced formation of calcium phosphate whilst maintaining the porosity and interconnectivity of the hydrogel polymers and would be very useful for the development of orthopaedic tissue engineering scaffolds.


Subject(s)
Biocompatible Materials/chemistry , Hydrogels/chemistry , Polyhydroxyethyl Methacrylate/chemistry , Titanium/chemistry , 3T3 Cells , Animals , Anthraquinones/chemistry , Body Fluids/chemistry , Calcification, Physiologic , Calcium Phosphates/chemistry , Materials Testing , Mice , Microscopy, Electron, Scanning/methods , Porosity , Spectroscopy, Fourier Transform Infrared/methods , Stress, Mechanical , Tensile Strength , Time Factors , Tissue Engineering/methods , X-Ray Diffraction
18.
Expert Rev Med Devices ; 3(6): 805-15, 2006 Nov.
Article in English | MEDLINE | ID: mdl-17280545

ABSTRACT

This article reviews orbital implants used to replace an eye after enucleation or evisceration. Advantages of implant placement are described, with discussion of implant and wrap material, and design features that affect clinical outcomes. Implants may be porous or nonporous, pegged for linkage with a cosmetic shell or unpegged, and may be wrapped with a covering material or tissue or unwrapped. Device shape, volume and material qualities affect tissue tolerance and the risk of exposure or extrusion. Limitations of currently available devices are discussed, with factors affecting surgeon and patient choice. Ideally, a device should be easy to insert, avoid the need for wrapping or adjunctive tissues, be light, biointegratable, comfortable after implantation and provide satisfactory orbital volume replacement, movement and cosmesis without requiring further surgery or pegging. This review briefly discusses developments in implant design and aspects of design that affect function, but is not a detailed clinical review; rather, it aims to stimulate thought on optimal design and discusses recent developments. Novel technology in the form of a prototype device with a soft, biointegratable anterior surface is described as an example of newer approaches.


Subject(s)
Eye Enucleation/instrumentation , Eye Evisceration/instrumentation , Orbital Implants , Prosthesis Design , Humans , Porosity , Postoperative Complications/etiology
19.
Biomaterials ; 26(29): 5808-17, 2005 Oct.
Article in English | MEDLINE | ID: mdl-15949546

ABSTRACT

Poly(2-hydroxyethyl methacrylate) hydrogels were prepared in the presence of varying concentrations of water, or a co-monomer ethoxyethyl methacrylate at different strengths of crosslinking agent ethylene glycol dimethacrylate. Calcification tendency and its correlation with monomer mixture composition, topography and porosity of these materials were investigated. Scanning (SEM) and transmission electron microscopy (TEM) was used to study topography and porosity respectively. Calcification and calcium diffusion ability in to the hydrogels were investigated by light microscopy, SEM and energy dispersive analysis of X-rays (EDAX) after incubation of the materials in a metastable calcifying solution for 48 days. Polymer and solvent volume fractions were also studied to determine if a correlation existed between porosity and calcification. Most of the series of hydrogels showed surface irregularities. Internal structure showed evidence of a porous structure in one of the series. Calcification studies indicated diffusion of calcium ions in some of the series. The diffusion of calcium is limited to 30-40 microm in most calcified specimens. For hydrogels that exhibited substantial surface irregularities and micro channels, the infiltration of calcium up to 200 microm was observed. Attempts to detect porosity by electron microscopy failed in some of the hydrogels due to difficulty in sample processing and sectioning. However, collaboration of the results with different techniques used, indicated that surface defects are the major contributors to calcium deposition. Decrease in porosity reduces the amount of calcium deposits and infiltration with decreasing solvent volume fraction which is associated with crosslinking concentration and initial water content of the polymer.


Subject(s)
Biocompatible Materials/chemistry , Hydrogels/chemistry , Polyhydroxyethyl Methacrylate/chemistry , Calcium/chemistry , Cross-Linking Reagents/pharmacology , Diffusion , Hydrogel, Polyethylene Glycol Dimethacrylate , Materials Testing , Methacrylates/chemistry , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Polymers/chemistry , Porosity , Solvents/chemistry , X-Ray Diffraction
20.
Biomaterials ; 25(20): 5071-80, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15109870

ABSTRACT

A number of phase separation pHEMA sponge hydrogels have been prepared based on variations in monomer contents, concentration of cross-linking agent, solvent mixture and temperature of polymerization. The loading levels and release profiles of the anti-inflammatory drug prednisolone were examined for each of the pHEMA sponge materials. An effective diffusion coefficient determined by an optimization approach based on the experimental data was used to measure their release characteristics. The effect of morphological variations, revealed by the environmental scanning electron microscopy, and polymer/solvent volume fractions on these properties were discussed.


Subject(s)
Biocompatible Materials , Drug Delivery Systems , Polyhydroxyethyl Methacrylate/chemistry , Adhesives , Biomedical Engineering , Cross-Linking Reagents/pharmacology , Delayed-Action Preparations , Diffusion , Hydrogel, Polyethylene Glycol Dimethacrylate , Hydrogels , Microscopy, Electron, Scanning , Models, Statistical , Models, Theoretical , Polymers/chemistry , Prednisolone , Solvents , Spectrophotometry , Temperature , Time Factors , Ultraviolet Rays
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