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Chang-hua, Taiwan

Ito R.,Chang Gung University | Ito R.,Kyoto University | Wu C.-T.,Chang Gung Memorial Hospital | Lin M.C.-Y.,Chang Gung University | And 2 more authors.
Microsurgery | Year: 2016

Purpose This study was to investigate intraoperative assessment of side-to-end lymphovenous anastomosis (LVA) with indocyanine green (ICG) and the correlation between its patency and surgical outcome. Methods LVA was applied to five patients with early-stage lower extremity lymphedema. Side-to-end anastomosis and then end-to-end anastomosis were created as a second alternative. Immediately after the anastomosis, ICG was used to confirm its patency. Results The mean number of anastomoses was 2.0 ± 0.7, and the types of anastomoses were primarily side-to-end and secondarily end-to-end. The mean reduction rate was 63.8 ± 20.2% after LVA at 10 ± 6.4 months of follow-up. In all cases, the affected extremities became soft immediately after surgery, and no cellulitis episodes were observed. Conclusion Side-to-end LVA can be an effective treatment for early-stage lower extremity lymphedema. ICG lymphodynamic assessment is useful not only in the preoperative identification of functional lymphatics but also in the intraoperative visualization of new drainage routes in LVA surgery. © 2015 Wiley Periodicals, Inc. Source

Lai J.-Y.,Chang Gung University | Lai J.-Y.,Center for Tissue Engineering
International Journal of Molecular Sciences | Year: 2015

The development of porous hyaluronic acid (HA) hydrogels for corneal endothelial tissue engineering is attractive because they can be used as functional cell delivery carriers to help in the reconstruction of damaged areas. The purpose of this study was to investigate the corneal endothelial cytocompatibility and cell delivery performance of porous HA hydrogel biomaterials fabricated at different pre-freezing temperatures. As compared to their counterparts prepared at −80 °C, the HA samples fabricated at higher pre-freezing temperature (i.e., 0 °C) exhibited a larger pore size and higher porosity, thereby leading to lower resistance to glucose permeation. Live/dead assays and gene expression analyses showed that the restricted porous structure of HA carriers decreases the viability and ionic pump function of cultured corneal endothelial cells (CECs). The results also indicated that the porous hydrogel biomaterials fabricated at high pre-freezing temperature seem to be more compatible with rabbit CECs. In an animal model of corneal endothelial dysfunction, the wounded rabbit corneas receiving bioengineered CEC sheets and restricted porous-structured HA carriers demonstrated poor tissue reconstruction. The therapeutic efficacy of cell sheet transplants can be improved by using carrier materials prepared at high pre-freezing temperature. Our findings suggest that the cryogenic operation temperature-mediated pore microstructure of HA carriers plays an important role in corneal endothelial cytocompatibility and cell delivery performance. © 2015 by the authors; licensee MDPI, Basel, Switzerland. Source

Chou S.-F.,Chang Gung University | Chou S.-F.,University of Washington | Lai J.-Y.,Chang Gung University | Lai J.-Y.,Center for Tissue Engineering | And 2 more authors.
Colloids and Surfaces B: Biointerfaces | Year: 2016

Fabrication of the cell spheroids from corneal keratocytes has important implications to the advance in tissue engineering while stimulation from the interface of a biopolymer coating has the ability to modulate this event. This study aims to investigate the dependence of keratocyte migration, proliferation, and differentiation on the surface roughness/stiffness of the chitosan coatings through modifications by degree of deacetylation (DD). After a series of deacetylation process, chitosan coatings with increasing DD exhibited significantly decreased surface roughness and increased surface stiffness. Relationships between the behaviors of rabbit corneal keratocytes (RCKs) and biopolymer coatings with varying DDs (between 75% and 96%) were also found during in vitro cultivation. Both the surface roughness increase and stiffness decrease could lead to enhanced cell migration, which is the main driving force for the early stage spheroid formation on chitosan substrates (e.g., within 8 h). With these stimulations from the substrate interfaces, the size and morphology of RCK spheroids were greatly affected by the DD of chitosan. When fabricated on a lowered DD of chitosan material, the spheroids had a larger size with abundant extracellular matrix produced around the cells. At a later stage of spheroid cultivation (e.g., 5 days), significantly higher amount of RCKs on chitosan coatings was noted with increasing DD, indicating the substrate interface effects on cell proliferation. The keratocan expression of RCK spheroids grown on a lowered DD of chitosan was up-regulated, suggesting that both the surface roughness increase and stiffness decrease may facilitate the microenvironment for preservation of cellular phenotype. Overall, our work contributes to the scientific understanding of the keratocyte behaviors and spheroid fabrications in response to DD-mediated surface roughness/stiffness of chitosan coatings. © 2016 Elsevier B.V. Source

Lai J.-Y.,Chang Gung University | Lai J.-Y.,Center for Tissue Engineering
Materials Science and Engineering C | Year: 2016

In this study, the effects of hyaluronic acid (HA) concentrations (0.05-1.25 wt.%) on the properties of porous carriers for corneal endothelial tissue engineering were investigated. The pore size and porosity gradually increased with decreasing solid content. However, at relatively low HA concentration (i.e., 0.05 wt.%), the material samples contained small interior pores and a dense surface skin layer, probably due to no gas bubble effect on the stirring processing of porous microstructures of freeze-dried polysaccharide hydrogels. The carriers prepared from 0.25 wt.% HA solution had the highest freezable water content and oxygen and glucose permeability among the samples evaluated. Results of cell viability assays and quantitative real-time reverse transcription polymerase chain reaction analyses showed that the HA concentration-related alteration of porous microstructure dictates the compatibility of biopolymer carriers with corneal endothelial cell (CEC) cultures. In vivo studies demonstrated that the CEC sheet/HA carrier construct implants are therapeutically efficacious in the reconstruction of endothelial scrape-wounded corneas. It is concluded that the polysaccharide concentration is the major factor for affecting the processing of carriers and their structure and function. Porous hydrogels prepared from 0.25 wt.% HA solution are capable of delivering bioengineered CEC sheets to the posterior surface of cornea. © 2015 Elsevier B.V. All rights reserved. Source

Lai J.-Y.,Chang Gung University | Lai J.-Y.,Center for Tissue Engineering | Luo L.-J.,Chang Gung University
Biomacromolecules | Year: 2015

In clinical ophthalmology, oxidative stress has been proposed as the initiating cause of ocular hypertension, which is one of the risk factors for glaucomatous damage and disease progression. In an attempt to improve the therapeutic efficacy of intracamerally administered pilocarpine, herein, a cytoprotective antiglaucoma drug delivery system composed of antioxidant gallic acid (GA)-functionalized gelatin-g-poly(N-isopropylacrylamide) (GN) biodegradable in situ gelling copolymer was developed for the first time. Analyses by UV-vis and Fourier transform infrared spectroscopies showed the formation of biopolymer-antioxidant covalent linkages in GNGA structures through a radical reaction in the presence of water-soluble redox initiators. The synthesized GNGA polymers with strong free radical scavenging effectiveness exhibited appropriate phase transition temperature and degradation rate as injectable bioerodible depots for minimally invasive pilocarpine delivery to the ocular anterior chamber. During the 2-week in vitro study, the sustained releases of sufficient amounts of pilocarpine for a therapeutic action in alleviating ocular hypertension could be achieved under physiological conditions. Results of cell viability, intracellular reactive oxygen species level, and intracellular calcium concentration indicated that the incorporation of antioxidant GA into GN structure can enhance cytoprotective effects of carrier materials against hydrogen peroxide-induced oxidative stress in lens epithelial cultures. Effective pharmacological responses (i.e., reduction of intraocular pressure and preservation of corneal endothelial cell morphology and density) in rabbits receiving intracameral GNGA injections containing pilocarpine were evidenced by clinical observations. The findings of in vivo studies also support the hypothesis that the GNGA carriers are more advantageous over their GN counterparts for the improvement of total antioxidant status in glaucomatous eyes with chronic ocular hypertension. The synthesized multifunctional molecules may be further used as potential polymer therapeutics for intraocular delivery of bioactive agents. © 2015 American Chemical Society. Source

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