Molecular imprinted nanoparticles(MINPs) can memorize the shape and functional group positions complementary to template, which account for the large drug loading capacity and slow drug release behavior as drug carrie...Molecular imprinted nanoparticles(MINPs) can memorize the shape and functional group positions complementary to template, which account for the large drug loading capacity and slow drug release behavior as drug carriers. We synthesized MINPs via precipitation polymerization with vinblastine(VBL) as a model drug, and investigated the drug loading,releasing property in vitro and bio-distribution in vivo. The obtained MINPs, from 300 to 450 nm,had smooth surface and favorable dispersibility. The entrapment efficacy and drug loading capacity of VBL loaded MINPs(MINPs-VBL) were 83.25% and 8.72% respectively. In PBS(pH 7.4),MINPs-VBL showed sustained release behavior. The cumulative release percentage reached about 70% during 216 h and no burst release was observed. The releasing behavior of MINPsVBL in vitro conformed to the first-order kinetics model. MINPs-VBL and commercially available vinblastine sulfate injection(VBL injection) were injected via tail vein of SD rats respectively to investigate the bio-distribution. MINPs-VBL group showed higher concentration of VBL in tissues and serum than VBL injection group after 60 min, and the drug level in liver was the highest. MINPs-VBL exhibited liver targeting trend to some extent, which was based on the evaluation of drug targeting index(DTI) and drug selecting index(DSI).展开更多
β-TCP ceramics drug carrier was first prepared and characterized. SEM showed that β-TCP carrier was in porous amorphous structure with diameters around 10 μm. The physical properties including apparent porosity, vo...β-TCP ceramics drug carrier was first prepared and characterized. SEM showed that β-TCP carrier was in porous amorphous structure with diameters around 10 μm. The physical properties including apparent porosity, volume-weight, tensile strength and the permeability were measured and the results indicated those properties fit the clinical usage of β-TCP drug carrier. Furthermore, drug release experiment in vitro showed that the carrier could prolong drug release in simulated body fluid which provides basis for the clinical use of β-TCP ceramics as drug carrier.展开更多
To discuss the feasibility of bydroxyapatite bone cement （HAC） used as a drug delivery carrier and observe the bacteriostatic activity of HAC/ Norvancomycin（ HAC/ NVCM ） composite in vitro and its release charac...To discuss the feasibility of bydroxyapatite bone cement （HAC） used as a drug delivery carrier and observe the bacteriostatic activity of HAC/ Norvancomycin（ HAC/ NVCM ） composite in vitro and its release characteristics in vivo. Bacteriostatic zone and cycle of composite containing 1.5wt% of NVCM were measured in vitro studies. In vivo stndies , the composite was implanted into the top of rabbit＇ s tibia as the local medication group, HAC without NVCM being composed was also implanted and NVCM was injected into auricular vein as the systemic medication group. Cnncentrations of NVCM in blood and local bone were measured in both groups at different time points. The experimental results showed that HAC did not influence the bacteriostatic activity of NVCM otviously, and NVCM exist in the porosities of HAC in the pattern of amorphism. The blood coueemrations of NVCM in local medication group were always lower than those in systemic medication group at any time point, while the bone concentrations of NVCM in local medication group were much higher than those of systemic medication group,which remained to be 3.96μg/mg/mL after 2 weeks. And HAC has good release characteristics as a drug delivery earricr.展开更多
In different parts of the gastrointestinal tract, the rate of drug release from polyelectrolyte hydrogel tablets is highly affected by variance of ionic concentration. This research aims at revealing clearly how the d...In different parts of the gastrointestinal tract, the rate of drug release from polyelectrolyte hydrogel tablets is highly affected by variance of ionic concentration. This research aims at revealing clearly how the drug release from a hydrogel matrix is affected by ionic concentration of external solution through the finite element simulation and triphasic mechanism model. The coupled relationship of the motions including the polyelectrolyte hydrogel swelling, the water flow and the ion diffusion, is illustrated in the present work. In order to simulate the drug controlled release from a swollen polyelectrolyte hydrogel carrier, the mathematical model was built on the basis of the multiphasic theory of polyelectrolyte hydrogels. Finally, the reliability of the simulation method was verified qualitatively by experimental results. The results reveal that when the initial concentration of fixed anions of polymer network is higher than the concentration of free anions in the external solution, the drug release rate increases with increasing the ionic concentration of the external solution. The research is helpful for the optimal design of oral drug release in gastrointestinal tract.展开更多
Scar hyperplasia at the suture site is an important reason for hindering the repair effect of peripheral nerve injury anastomosis. To address this issue, two repair methods are often used. Biological agents are used t...Scar hyperplasia at the suture site is an important reason for hindering the repair effect of peripheral nerve injury anastomosis. To address this issue, two repair methods are often used. Biological agents are used to block nerve sutures and the surrounding tissue to achieve phys- ical anti-adhesion effects. Another agent is glucocorticosteroid, which can prevent scar growth by inhibiting inflammation. However, the overall effect of promoting regeneration of the injured nerve is not satisfactory. In this regard, we envision that these two methods can be combined and lead to shared understanding for achieving improved nerve repair. In this study, the right tibial nerve was transected 1 cm above the knee to establish a rat tibial nerve injury model. The incision was directly sutured after nerve transection. The anastomotic stoma was coated with 0.5 × 0.5 cm^2 chitosan sheets with betamethasone dipropionate. At 12 weeks after injury, compared with the con- trol and poly （D, L-lactic acid） groups, chitosan-betamethasone dipropionate film slowly degraded with the shape of the membrane still intact. Further, scar hyperplasia and the degree of adhesion at anastomotic stoma were obviously reduced, while the regenerated nerve fiber structure was complete and arranged in a good order in model rats. Electrophysiological study showed enhanced compound muscle action potential. Our results confirm that chitosan-betamethasone dipropionate film can effectively prevent local scar hyperplasia after tibial nerve repair and promote nerve regeneration.展开更多
基金supported by the National Natural Science Foundation of China (grant number: 81173566)
文摘Molecular imprinted nanoparticles(MINPs) can memorize the shape and functional group positions complementary to template, which account for the large drug loading capacity and slow drug release behavior as drug carriers. We synthesized MINPs via precipitation polymerization with vinblastine(VBL) as a model drug, and investigated the drug loading,releasing property in vitro and bio-distribution in vivo. The obtained MINPs, from 300 to 450 nm,had smooth surface and favorable dispersibility. The entrapment efficacy and drug loading capacity of VBL loaded MINPs(MINPs-VBL) were 83.25% and 8.72% respectively. In PBS(pH 7.4),MINPs-VBL showed sustained release behavior. The cumulative release percentage reached about 70% during 216 h and no burst release was observed. The releasing behavior of MINPsVBL in vitro conformed to the first-order kinetics model. MINPs-VBL and commercially available vinblastine sulfate injection(VBL injection) were injected via tail vein of SD rats respectively to investigate the bio-distribution. MINPs-VBL group showed higher concentration of VBL in tissues and serum than VBL injection group after 60 min, and the drug level in liver was the highest. MINPs-VBL exhibited liver targeting trend to some extent, which was based on the evaluation of drug targeting index(DTI) and drug selecting index(DSI).
基金Funded by the "973" Chinese National Key Fundamental Research and Development Program (No.G1999064701)the Research Fund of Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province (AE201037)
文摘β-TCP ceramics drug carrier was first prepared and characterized. SEM showed that β-TCP carrier was in porous amorphous structure with diameters around 10 μm. The physical properties including apparent porosity, volume-weight, tensile strength and the permeability were measured and the results indicated those properties fit the clinical usage of β-TCP drug carrier. Furthermore, drug release experiment in vitro showed that the carrier could prolong drug release in simulated body fluid which provides basis for the clinical use of β-TCP ceramics as drug carrier.
文摘To discuss the feasibility of bydroxyapatite bone cement （HAC） used as a drug delivery carrier and observe the bacteriostatic activity of HAC/ Norvancomycin（ HAC/ NVCM ） composite in vitro and its release characteristics in vivo. Bacteriostatic zone and cycle of composite containing 1.5wt% of NVCM were measured in vitro studies. In vivo stndies , the composite was implanted into the top of rabbit＇ s tibia as the local medication group, HAC without NVCM being composed was also implanted and NVCM was injected into auricular vein as the systemic medication group. Cnncentrations of NVCM in blood and local bone were measured in both groups at different time points. The experimental results showed that HAC did not influence the bacteriostatic activity of NVCM otviously, and NVCM exist in the porosities of HAC in the pattern of amorphism. The blood coueemrations of NVCM in local medication group were always lower than those in systemic medication group at any time point, while the bone concentrations of NVCM in local medication group were much higher than those of systemic medication group,which remained to be 3.96μg/mg/mL after 2 weeks. And HAC has good release characteristics as a drug delivery earricr.
文摘In different parts of the gastrointestinal tract, the rate of drug release from polyelectrolyte hydrogel tablets is highly affected by variance of ionic concentration. This research aims at revealing clearly how the drug release from a hydrogel matrix is affected by ionic concentration of external solution through the finite element simulation and triphasic mechanism model. The coupled relationship of the motions including the polyelectrolyte hydrogel swelling, the water flow and the ion diffusion, is illustrated in the present work. In order to simulate the drug controlled release from a swollen polyelectrolyte hydrogel carrier, the mathematical model was built on the basis of the multiphasic theory of polyelectrolyte hydrogels. Finally, the reliability of the simulation method was verified qualitatively by experimental results. The results reveal that when the initial concentration of fixed anions of polymer network is higher than the concentration of free anions in the external solution, the drug release rate increases with increasing the ionic concentration of the external solution. The research is helpful for the optimal design of oral drug release in gastrointestinal tract.
文摘Scar hyperplasia at the suture site is an important reason for hindering the repair effect of peripheral nerve injury anastomosis. To address this issue, two repair methods are often used. Biological agents are used to block nerve sutures and the surrounding tissue to achieve phys- ical anti-adhesion effects. Another agent is glucocorticosteroid, which can prevent scar growth by inhibiting inflammation. However, the overall effect of promoting regeneration of the injured nerve is not satisfactory. In this regard, we envision that these two methods can be combined and lead to shared understanding for achieving improved nerve repair. In this study, the right tibial nerve was transected 1 cm above the knee to establish a rat tibial nerve injury model. The incision was directly sutured after nerve transection. The anastomotic stoma was coated with 0.5 × 0.5 cm^2 chitosan sheets with betamethasone dipropionate. At 12 weeks after injury, compared with the con- trol and poly （D, L-lactic acid） groups, chitosan-betamethasone dipropionate film slowly degraded with the shape of the membrane still intact. Further, scar hyperplasia and the degree of adhesion at anastomotic stoma were obviously reduced, while the regenerated nerve fiber structure was complete and arranged in a good order in model rats. Electrophysiological study showed enhanced compound muscle action potential. Our results confirm that chitosan-betamethasone dipropionate film can effectively prevent local scar hyperplasia after tibial nerve repair and promote nerve regeneration.
