title: Intracellular delivery of messenger RNA by recombinant PP7 virus-like particles carrying low molecular weight protamine.
abstract: Cell-penetrating peptides (CPPs) have been widely used as carriers to transport different molecules into living cells, whereas messenger RNAs (mRNAs) have been utilized as target molecules for the prevention and treatment of various diseases. However, the instability of CPPs and mRNAs has limited their application. Bacteriophage PP7 virus-like particles (VLPs) may protect peptides and RNAs from degradation through displaying foreign peptides on their surface and encapsidating RNA linked with the pac site.
  
  
  
  In this study, the cDNA of the PP7 coat protein single-chain dimer carrying low molecular weight protamine (LMWP) and the cDNA of green fluorescent protein (GFP) were inserted into two multiple cloning sites of pETDuet-1, respectively. PP7 VLPs carrying the LMWP peptide and GFP mRNA were subsequently expressed in Escherichia coli BL21 (DE3) with high yield and thermal stability, and were easily purified. The VLPs were also non-replicative, non-infectious, and non-toxic. Moreover, they penetrated the mouse prostate cancer cells RM-1 after 24 h incubation. Last, PP7 VLPs carrying the LMWP could encapsidate the GFP mRNA, which was translated into mature protein in mammalian cells.
  
  
  
  Recombinant PP7 VLPs can be used simultaneously as a targeted delivery vector for both peptides and mRNA due to their abilities to package RNA and display peptides.
authors.affiliation: Institute of Nanomedicine Technology, Department of Laboratory Medicine, Institutional Key Laboratory of Clinical Laboratory Diagnostics, 12th 5-Year Project of Shandong Province, Key Discipline of Clinical Laboratory Medicine of Shandong Province, Affiliated Hospital of Weifang Medical University, Weifang Medical University, Weifang, 261053, China.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Department of Hematology, Weifang People's Hospital, Weifang, 261000, China. zhgzbxforget@163.com.
authors.forename: Yanhua
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Institute of Nanomedicine Technology, Department of Laboratory Medicine, Institutional Key Laboratory of Clinical Laboratory Diagnostics, 12th 5-Year Project of Shandong Province, Key Discipline of Clinical Laboratory Medicine of Shandong Province, Affiliated Hospital of Weifang Medical University, Weifang Medical University, Weifang, 261053, China.
authors.forename: Ronglan
authors.initials: R
authors.lastname: Zhao
authors.affiliation: Department of Laboratory Medicine of Affiliated Hospital of Weifang Medical University, Weifang Medical University, Weifang, 261031, China.
authors.forename: Kunshan
authors.initials: K
authors.lastname: Gao
mesh_terms: D000818:Animals; D001435:Bacteriophages / Q000378:metabolism*; D045744:Cell Line, Tumor; D004926:Escherichia coli / Q000235:genetics* / Q000821:virology; D008297:Male; D051379:Mice; D008970:Molecular Weight; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000378:metabolism; D011479:Protamines / Q000493:pharmacokinetics*; D012333:RNA, Messenger / Q000008:administration & dosage* / Q000235:genetics*; D011994:Recombinant Proteins / Q000493:pharmacokinetics; D014162:Transfection / Q000379:methods; D014771:Virion
chemical_list: D011479:Protamines; D012333:RNA, Messenger; D011994:Recombinant Proteins
keywords: Low molecular weight protamine; Messenger RNA; PP7 bacteriophage; Peptide display; Virus-like particle