title: [Synthesis and experimental study of a novel polymer/gene compound drug controlled release system for the treatment of erectile dysfunction].
abstract: OBJECTIVE
  To overcome the deficiency in the current therapies for erectile dysfunction (ED), we designed and synthesized a novel high-efficiency polymer/gene compound drug controlled release system and discussed the feasibility of pH and temperature dually sensitive injectable hydrogel in ED gene therapy.
  
  
  METHODS
  We synthesized optimal siRNA gene nanoparticles by characterizing the zeta potential of polylysine (PLL)/siRNA gene compounds, and established a pH and temperature dually sensitive injectable gene compound drug controlled release system via Schiffs reaction between glycol chitosan (GC) and benzaldehyde capped OHC-PEO-PPO-PEO-CHO. Then we demonstrated the sustained release of the system at different temperatures.
  
  
  RESULTS
  When the mass ratio of PLL to siRNA was 20:1, the zeta potential of the PLL/siRNA gene compound reached the peak (+23.5 mV) and the siRNA was encapsulated by PLL in the maximal degree. GC and OHC-PEO-PPO-PEO-CHO was crosslinked via benzoicimine reaction when environmental pH was changed from 5.5 to 7.4. The reslease of the siRNA encapsulated in this system kept at a low rate at 37 degrees C, significantly enhanced with the increase of the temperature to 60 degrees C, rising to (122.5 +/- 5.3) microg at 1 000 minutes as compared with (23.8 +/- 6.0) microg at 37 degrees C (P < 0.05).
  
  
  CONCLUSIONS
  The polymer/gene compound drug controlled release system was successfully synthesized, which improved the stability and capacity of gene carriers and achieved siRNA release at different temperatures, promising to be a new approach to the gene therapy of ED.
authors.affiliation: Department of Urology, People Hospital of Peking University, Beijing 100044, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Urology, Beijing Chaoyang Hospital, Beijing 100020, China.
authors.forename: Wen-Rui
authors.initials: WR
authors.lastname: Xue
authors.affiliation: Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Ling-Ling
authors.initials: LL
authors.lastname: Zhao
authors.affiliation: Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Xiao-Zhong
authors.initials: XZ
authors.lastname: Qu
authors.affiliation: Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Zhen-Zhong
authors.initials: ZZ
authors.lastname: Yang
authors.affiliation: Department of Urology, People Hospital of Peking University, Beijing 100044, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Li
authors.affiliation: Department of Urology, People Hospital of Peking University, Beijing 100044, China.
authors.forename: Shi-Zhou
authors.initials: SZ
authors.lastname: Deng
authors.affiliation: Department of Urology, People Hospital of Peking University, Beijing 100044, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Xiao
authors.affiliation: Department of Urology, Beijing Chaoyang Hospital, Beijing 100020, China.
authors.forename: Xiao-Peng
authors.initials: XP
authors.lastname: Hu
authors.affiliation: Department of Urology, People Hospital of Peking University, Beijing 100044, China.
authors.forename: Wen-Jun
authors.initials: WJ
authors.lastname: Bai
mesh_terms: D003692:Delayed-Action Preparations / Q000494:pharmacology*; D016503:Drug Delivery Systems; D007172:Erectile Dysfunction / Q000188:drug therapy*; D015316:Genetic Therapy; D006801:Humans; D008297:Male; D053758:Nanoparticles / Q000737:chemistry; D011107:Polylysine / Q000737:chemistry; D011108:Polymers; D034741:RNA, Small Interfering / Q000494:pharmacology
chemical_list: D003692:Delayed-Action Preparations; D011108:Polymers; D034741:RNA, Small Interfering; D011107:Polylysine