AIM：To strengthen the biomechanics of collagen by crosslinking rabbit scleral collagen with genipin to develop a new therapy for preventing myopic progression. METHODS：Ten New Zealand rabbits were treated with 0.5 m...AIM：To strengthen the biomechanics of collagen by crosslinking rabbit scleral collagen with genipin to develop a new therapy for preventing myopic progression. METHODS：Ten New Zealand rabbits were treated with 0.5 mmol/L genipin injected into the sub-Tenon＇s capsule in the right eyes. Untreated contralateral eyes served as the control. The treated area was cut into scleral strips measuring 4.0 mm×10.0 mm for stress-strain measurements（n=5）. The remaining five treated eyes were prepared for histological examination.RESULTS：Compared to the untreated scleral strips,the genipin-crosslinked scleral strips showed that the ultimate stress and Young＇s modulus at 10% strain were increased by the amplitude of 130% and 303% respectively,ultimate strain was decreased by 24%. There had no α-smooth muscle actin（α-SMA）positive cells in control and treated sclera. Histologically,there was no sign of apoptosis in the sclera,choroid,and retina; and no side effects were found in the peripheral cornea and optic nerve adjacent to the treatment area.CONCLUSION：Genipin induced crosslinking of collagen can increase its biomechanical behavior by direct strengthening of the extracellular matrix in rabbit sclera,with no α-SMA expression seen in the myofibroblasts. As there is no evidence of cytotoxicity in the scleral,choroidal,and retinal cells,genipin is likely a promising agent to strengthen the weakened sclera to prevent myopic progression.展开更多
Crosslinked biopolymers were prepared for controlled release to investigate the diffusion of ascorbic acid from swelling high-solid networks in neutral and acidic pH conditions.Polymer swelling was measured at pH 2.8 ...Crosslinked biopolymers were prepared for controlled release to investigate the diffusion of ascorbic acid from swelling high-solid networks in neutral and acidic pH conditions.Polymer swelling was measured at pH 2.8 and pH 6.8 and change in microstructural properties,including network mesh size and average molecular weight between crosslinks of genipin-crosslinked gelatin and genipin-crosslinked chitosan systems,were predicted.Variable mathematical modelling was applied to the first 60%of ascorbic acid diffusion and statistical analysis was used to determine the model that best fits the experimental data.Molecular transport from the gelatin-based networks was best described by the Peppas-Sahlin model whereas the distinct effect of pH on chitosan structure formation brought into consideration the zero-order model.Mathematical modelling of bioactive compound release from swelling biopolymer matrices at different pH conditions is essential for the design of efficient targeted delivery matrices for functional food and nutraceutical applications.展开更多
基金Supported by Guangdong Province Science and Technology Projects(No.2007B031002001)
文摘AIM：To strengthen the biomechanics of collagen by crosslinking rabbit scleral collagen with genipin to develop a new therapy for preventing myopic progression. METHODS：Ten New Zealand rabbits were treated with 0.5 mmol/L genipin injected into the sub-Tenon＇s capsule in the right eyes. Untreated contralateral eyes served as the control. The treated area was cut into scleral strips measuring 4.0 mm×10.0 mm for stress-strain measurements（n=5）. The remaining five treated eyes were prepared for histological examination.RESULTS：Compared to the untreated scleral strips,the genipin-crosslinked scleral strips showed that the ultimate stress and Young＇s modulus at 10% strain were increased by the amplitude of 130% and 303% respectively,ultimate strain was decreased by 24%. There had no α-smooth muscle actin（α-SMA）positive cells in control and treated sclera. Histologically,there was no sign of apoptosis in the sclera,choroid,and retina; and no side effects were found in the peripheral cornea and optic nerve adjacent to the treatment area.CONCLUSION：Genipin induced crosslinking of collagen can increase its biomechanical behavior by direct strengthening of the extracellular matrix in rabbit sclera,with no α-SMA expression seen in the myofibroblasts. As there is no evidence of cytotoxicity in the scleral,choroidal,and retinal cells,genipin is likely a promising agent to strengthen the weakened sclera to prevent myopic progression.
基金This research is supported by an Australian Government Research Training Program(RTP)Scholarship to Felicity Whitehead.
文摘Crosslinked biopolymers were prepared for controlled release to investigate the diffusion of ascorbic acid from swelling high-solid networks in neutral and acidic pH conditions.Polymer swelling was measured at pH 2.8 and pH 6.8 and change in microstructural properties,including network mesh size and average molecular weight between crosslinks of genipin-crosslinked gelatin and genipin-crosslinked chitosan systems,were predicted.Variable mathematical modelling was applied to the first 60%of ascorbic acid diffusion and statistical analysis was used to determine the model that best fits the experimental data.Molecular transport from the gelatin-based networks was best described by the Peppas-Sahlin model whereas the distinct effect of pH on chitosan structure formation brought into consideration the zero-order model.Mathematical modelling of bioactive compound release from swelling biopolymer matrices at different pH conditions is essential for the design of efficient targeted delivery matrices for functional food and nutraceutical applications.
