Poly(methacrylic acid co-poloxamer) hydrogel networks were synthesized by free radical solution polymerization and their equilibrium swelling and solute permeation properties were characterized. These gels exhibited p...Poly(methacrylic acid co-poloxamer) hydrogel networks were synthesized by free radical solution polymerization and their equilibrium swelling and solute permeation properties were characterized. These gels exhibited pH dependant swelling and solute diffusivity due to the formation or disruption of hydrogen bonded complexation between methacrylic acid (MAA) and etheric (EO). In neutral and basic conditions (above the swelling transition pH), the copolymer swelling was greatly higher than acid condition. In complexed hydrogels, the diffusion coefficients of vitamin B12 (VB12) were in the range of 10-10 to 10-7 cm2s-1; While in uncomplexed hydrogels, the values were about 210-6 cm2s-1. The comonomer composition and synthesis conditions have great effect on the structure, and thereby, swelling and solute diffusion characteristics of the resultant hydrogels. For the copolymers with composition of less than or more than 1:1 MAA/EO molar ratio, the plot of lnD vs 1/H-1 followed two different linear equations of 慺ree volume theory? respectively.展开更多
目的建立一种新型Poloxamer 407(P407)温敏性即型凝胶培养体系,以探讨P407凝胶对铜绿假单胞菌药物敏感性的影响。方法临床分离17株铜绿假单胞菌,采用改良K-B纸片法检测细菌药物敏感性;通过RT-PCR、扫描电镜(Scanning electron microscop...目的建立一种新型Poloxamer 407(P407)温敏性即型凝胶培养体系,以探讨P407凝胶对铜绿假单胞菌药物敏感性的影响。方法临床分离17株铜绿假单胞菌,采用改良K-B纸片法检测细菌药物敏感性;通过RT-PCR、扫描电镜(Scanning electron microscopy,SEM)观察在P407和传统琼脂培养基中细菌生物膜形成情况。结果药敏结果显示在两种培养基上抑菌圈大小有显著差异(P<0.05);SEM下可见传统琼脂培养基上有大量杆状细菌,而在P407培养基上可见这些杆状细菌聚集在一起,被细胞外基质所包裹;RT-PCR结果显示,在P407培养基上alg C和alg D基因有明显表达,并随培养时间的延长逐渐增强。结论 P407作为一种细菌培养基赋形剂,可用于临床药物敏感试验筛选。展开更多
In the present study, we aimed to prepare poloxamer 403/407 mixed micelles in order to improve the solubility and oral bioavailability of genistein. Genistein was incorporated in the mixed poloxamer micelles by thin-f...In the present study, we aimed to prepare poloxamer 403/407 mixed micelles in order to improve the solubility and oral bioavailability of genistein. Genistein was incorporated in the mixed poloxamer micelles by thin-film hydration method, and its physicochemical properties, including particle size, zeta potential, entrapment efficiency and drug loading, were investigated. In vitro release of genistein from the mixed micelles was monitored by dialysis method, and pharmacokinetic study of genistein loaded mixed micelles was carried out in rats. We found that the particle size and zeta potential of mixed micelles were（20.31±0.43） nm and（–8.94±0.35） m V, with encapsulation efficiency 90.59%±0.67% and drug loading 7.74%±0.05%. Solubility of genistein in mixed micelles reached 3.80 mg/m L, which was about 130 times higher than that in water. Genistein-loaded mixed micelles showed sustained release characteristics in vitro with no burst release phenomenon, but it was faster than suspension. The AUC0–t and AUC0–∞ of mixed micelles were 196.74% and 204.62% greater than that of genisein suspension, respectively. Consequently, poloxamer 403/407 mixed micelles significantly improved the solubility and oral bioavailability of genistein, which could be used as an effective drug delivery system for oral administration of poorly soluble drugs.展开更多
AIM To assess the insulating effect of a poloxamer 407(P407)-based gel during microwave ablation of liver adjacent to the diaphragm.METHODS We prepared serial dilutions of P407, and 22.5%(w/w) concentration was identi...AIM To assess the insulating effect of a poloxamer 407(P407)-based gel during microwave ablation of liver adjacent to the diaphragm.METHODS We prepared serial dilutions of P407, and 22.5%(w/w) concentration was identified as suitable for ablation procedures. Subsequently, microwave ablations were performed on the livers of 24 rabbits(gel, saline, control groups, n = 8 in each). The P407 solution and 0.9% normal saline were injected into the potential space between the diaphragm and liver in experimental groups. No barriers were applied to the controls. After microwave ablations, the frequency, size and degree of thermal injury were compared histologically among the three groups. Subsequently, another 8 rabbits were injected with the P407 solution and microwave ablation was performed. The levels of alanine aminotransferase(ALT), aspartate aminotransferase(AST), blood urea nitrogen(BUN) and creatinine(Cr) in serum were tested at 1 d before microwave ablation and 3 and 7 d after operation. RESULTS In vivo ablation thermal injury to the adjacent diaphragm was evaluated in the control, saline and 22.5% P407 gel groups(P = 0.001-0.040). However, there was no significant difference in the volume of ablation zone among the three groups(P > 0.05). Moreover, there were no statistical differences among the preoperative and postoperative gel groups according to the levels of ALT, AST, BUN and Cr in serum(all P > 0.05).CONCLUSION Twenty-two point five percent P407 gel could be a more effective choice during microwave ablation of hepatic tumors adjacent to the diaphragm. Further studies for clinical translation are warranted.展开更多
文摘Poly(methacrylic acid co-poloxamer) hydrogel networks were synthesized by free radical solution polymerization and their equilibrium swelling and solute permeation properties were characterized. These gels exhibited pH dependant swelling and solute diffusivity due to the formation or disruption of hydrogen bonded complexation between methacrylic acid (MAA) and etheric (EO). In neutral and basic conditions (above the swelling transition pH), the copolymer swelling was greatly higher than acid condition. In complexed hydrogels, the diffusion coefficients of vitamin B12 (VB12) were in the range of 10-10 to 10-7 cm2s-1; While in uncomplexed hydrogels, the values were about 210-6 cm2s-1. The comonomer composition and synthesis conditions have great effect on the structure, and thereby, swelling and solute diffusion characteristics of the resultant hydrogels. For the copolymers with composition of less than or more than 1:1 MAA/EO molar ratio, the plot of lnD vs 1/H-1 followed two different linear equations of 慺ree volume theory? respectively.
基金The Zhejiang Public Welfare Technology Application Research Project(Grant No.2015C31100)the Ningbo Science and Technology Innovation Team Project(Grant No.2015C110027)
文摘In the present study, we aimed to prepare poloxamer 403/407 mixed micelles in order to improve the solubility and oral bioavailability of genistein. Genistein was incorporated in the mixed poloxamer micelles by thin-film hydration method, and its physicochemical properties, including particle size, zeta potential, entrapment efficiency and drug loading, were investigated. In vitro release of genistein from the mixed micelles was monitored by dialysis method, and pharmacokinetic study of genistein loaded mixed micelles was carried out in rats. We found that the particle size and zeta potential of mixed micelles were（20.31±0.43） nm and（–8.94±0.35） m V, with encapsulation efficiency 90.59%±0.67% and drug loading 7.74%±0.05%. Solubility of genistein in mixed micelles reached 3.80 mg/m L, which was about 130 times higher than that in water. Genistein-loaded mixed micelles showed sustained release characteristics in vitro with no burst release phenomenon, but it was faster than suspension. The AUC0–t and AUC0–∞ of mixed micelles were 196.74% and 204.62% greater than that of genisein suspension, respectively. Consequently, poloxamer 403/407 mixed micelles significantly improved the solubility and oral bioavailability of genistein, which could be used as an effective drug delivery system for oral administration of poorly soluble drugs.
基金Supported by the Clinical-Basic Cooperation Program from Capital Medical University,No.15JL10the National Key Research and Development Program,No.2016YFA0201504the Beijing Training Project For The Leading Talents in S&T,No.Z14110700154002
文摘AIM To assess the insulating effect of a poloxamer 407(P407)-based gel during microwave ablation of liver adjacent to the diaphragm.METHODS We prepared serial dilutions of P407, and 22.5%(w/w) concentration was identified as suitable for ablation procedures. Subsequently, microwave ablations were performed on the livers of 24 rabbits(gel, saline, control groups, n = 8 in each). The P407 solution and 0.9% normal saline were injected into the potential space between the diaphragm and liver in experimental groups. No barriers were applied to the controls. After microwave ablations, the frequency, size and degree of thermal injury were compared histologically among the three groups. Subsequently, another 8 rabbits were injected with the P407 solution and microwave ablation was performed. The levels of alanine aminotransferase(ALT), aspartate aminotransferase(AST), blood urea nitrogen(BUN) and creatinine(Cr) in serum were tested at 1 d before microwave ablation and 3 and 7 d after operation. RESULTS In vivo ablation thermal injury to the adjacent diaphragm was evaluated in the control, saline and 22.5% P407 gel groups(P = 0.001-0.040). However, there was no significant difference in the volume of ablation zone among the three groups(P > 0.05). Moreover, there were no statistical differences among the preoperative and postoperative gel groups according to the levels of ALT, AST, BUN and Cr in serum(all P > 0.05).CONCLUSION Twenty-two point five percent P407 gel could be a more effective choice during microwave ablation of hepatic tumors adjacent to the diaphragm. Further studies for clinical translation are warranted.
