title: Encapsulation of cisplatin in a pegylated calcium phosphate nanoparticle (CPNP) for enhanced cytotoxicity to cancerous cells.
abstract: Exchange of the chloride ion (Cl-) ligands of cisplatin with carboxylates is widely used in fabricating cisplatin loaded nanoparticles for improved cancer therapy. However, the dynamic exchange may cause premature cisplatin release and even disintegration of the nanoparticles in Cl--containing medium such as in plasma. Molecules bearing carboxylates are capable of mediating the mineralization process of calcium phosphate; therefore, it is possible to overcome the disadvantage by sequestering cisplatin in a calcium phosphate nanoparticle (CPNP).
  
  
  
  With the hypothesis, precipitation reaction of calcium nitrate and disodium hydrogen phosphate was performed in a solution of poly(ethylene glycol)-poly(acrylic acid) block copolymers with their carboxylates partly conjugated with cisplatin. Then, structure, physicochemical properties, and bioactivity of the product were carefully investigated with multiple characterization methods.
  
  
  
  It was revealed a pegylated, cisplatin encapsulated CPNP was prepared; and with appropriate mole ratio of cisplatin to carboxylates, the nanoparticle encapsulated cisplatin efficiently (>90%), was stable and almost entirely prevented the cisplatin release in Cl--containing medium at pH 7.4 but released them in an acidic condition, and showed moderately and greatly enhanced cytotoxicities to the lung cancer cell line A549 and its cisplatin resistance form A549R respectively in comparison with the free cisplatin.
authors.affiliation: School of Biological and Medical Engineering, Hefei University of Technology, Hefei 230009, PR China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Ding
authors.affiliation: School of Biological and Medical Engineering, Hefei University of Technology, Hefei 230009, PR China.
authors.forename: Kang
authors.initials: K
authors.lastname: Zhai
authors.affiliation: School of Biological and Medical Engineering, Hefei University of Technology, Hefei 230009, PR China.
authors.forename: Pei
authors.initials: P
authors.lastname: Pei
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei 230026, PR China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Lin
authors.affiliation: School of Biological and Medical Engineering, Hefei University of Technology, Hefei 230009, PR China.
authors.forename: Yinchu
authors.initials: Y
authors.lastname: Ma
authors.affiliation: School of Biological and Medical Engineering, Hefei University of Technology, Hefei 230009, PR China.
authors.forename: Huixia
authors.initials: H
authors.lastname: Zhu
authors.affiliation: Department of Urology, The First Affiliated Hospital of Anhui University of Traditional Chinese Medicine, Hefei, Anhui 230031, PR China. Electronic address: sssmmmfff@126.com.
authors.forename: Mingfeng
authors.initials: M
authors.lastname: Shao
authors.affiliation: School of Biological and Medical Engineering, Hefei University of Technology, Hefei 230009, PR China. Electronic address: yangxz@hfut.edu.cn.
authors.forename: Xianzhu
authors.initials: X
authors.lastname: Yang
authors.affiliation: School of Biological and Medical Engineering, Hefei University of Technology, Hefei 230009, PR China. Electronic address: taow@hfut.edu.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Tao
mesh_terms: D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000737:chemistry / Q000494:pharmacology*; D002130:Calcium Phosphates / Q000008:administration & dosage* / Q000737:chemistry; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000008:administration & dosage* / Q000737:chemistry / Q000494:pharmacology*; D004337:Drug Carriers / Q000008:administration & dosage / Q000737:chemistry*; D019008:Drug Resistance, Neoplasm / Q000187:drug effects; D006801:Humans; D006863:Hydrogen-Ion Concentration; D053758:Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry; D011092:Polyethylene Glycols / Q000008:administration & dosage / Q000737:chemistry*
chemical_list: D000970:Antineoplastic Agents; D002130:Calcium Phosphates; D004337:Drug Carriers; D011092:Polyethylene Glycols; D002945:Cisplatin
keywords: Calcium phosphate nanoparticle (CPNP); Cisplatin; Cisplatin resistance; Drug delivery; Encapsulation; Premature release