title: Controlled release of paclitaxel from a self-assembling peptide hydrogel formed in situ and antitumor study in vitro.
abstract: BACKGROUND
  A nanoscale injectable in situ-forming hydrogel drug delivery system was developed in this study. The system was based on a self-assembling peptide RADA16 solution, which can spontaneously form a hydrogel rapidly under physiological conditions. We used the RADA16 hydrogel for the controlled release of paclitaxel (PTX), a hydrophobic antitumor drug.
  
  
  METHODS
  The RADA16-PTX suspension was prepared simply by magnetic stirring, followed by atomic force microscopy, circular dichroism analysis, dynamic light scattering, rheological analysis, an in vitro release assay, and a cell viability test.
  
  
  RESULTS
  The results indicated that RADA16 and PTX can interact with each other and that the amphiphilic peptide was able to stabilize hydrophobic drugs in aqueous solution. The particle size of PTX was markedly decreased in the RADA16 solution compared with its size in water. The RADA16-PTX suspension could form a hydrogel in culture medium, and the elasticity of the hydrogel showed a positive correlation with peptide concentration. In vitro release measurements indicated that hydrogels with a higher peptide concentration had a longer half-release time. The RADA16-PTX hydrogel could effectively inhibit the growth of the breast cancer cell line, MDA-MB-435S, in vitro, and hydrogels with higher peptide concentrations were more effective at inhibiting tumor cell proliferation. The RADA16-PTX hydrogel was effective at controlling the release of PTX and inhibiting tumor cell growth in vitro.
  
  
  CONCLUSIONS
  Self-assembling peptide hydrogels may work well as a system for drug delivery.
authors: West China Hospital Laboratory of Nanomedicine and Institute for Nanobiomedical Technology and Membrane Biology, Sichuan University, Chengdu, China.
authors: Jingping
authors: J
authors: Liu
authors: Lanlan
authors: L
authors: Zhang
authors: Zehong
authors: Z
authors: Yang
authors: Xiaojun
authors: X
authors: Zhao
mesh_terms: D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000737:chemistry* / Q000493:pharmacokinetics; D001943:Breast Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D003102:Colloids; D003692:Delayed-Action Preparations; D004355:Drug Stability; D005260:Female; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D036103:Nanotechnology; D017239:Paclitaxel / Q000008:administration & dosage* / Q000737:chemistry* / Q000493:pharmacokinetics; D010316:Particle Size; D010455:Peptides / Q000737:chemistry*
chemical_list: D000970:Antineoplastic Agents; D003102:Colloids; D003692:Delayed-Action Preparations; D010455:Peptides; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D017239:Paclitaxel