title: Folic acid conjugated cross-linked acrylic polymer (FA-CLAP) hydrogel for site specific delivery of hydrophobic drugs to cancer cells.
abstract: BACKGROUND
  The hydrogel based system is found to be rarely reported for the delivery of hydrophobic drug due to the incompatibility of hydrophilicity of the polymer network and the hydrophobicity of drug. This problem can be solved by preparing semi-interpenetrating network of cross-linked polymer for tuning the hydrophilicity so as to entrap the hydrophobic drugs. The current study is to develop a folic acid conjugated cross-linked pH sensitive, biocompatible polymeric hydrogel to achieve a site specific drug delivery. For that, we have synthesized a folic acid conjugated PEG cross-linked acrylic polymer (FA-CLAP) hydrogel and investigated its loading and release of curcumin. The formed polymer hydrogel was then conjugated with folic acid for the site specific delivery of curcumin to cancer cells and then further characterized and conducted the cell uptake and cytotoxicity studies on human cervical cancer cell lines (HeLa).
  
  
  RESULTS
  In this study, we synthesized folic acid conjugated cross-linked acrylic hydrogel for the delivery of hydrophobic drugs to the cancer site. Poly (ethyleneglycol) (PEG) diacrylate cross-linked acrylic polymer (PAA) was prepared via inverse emulsion polymerization technique and later conjugated it with folic acid (FA-CLAP). Hydrophobic drug curcumin is entrapped into it and investigated the entrapment efficiency. Characterization of synthesized hydogel was done by using Fourier Transform-Infrared spectroscopy (FT-IR), Transmission Electron Microscopy (TEM), Differential Scanning Calorimetry (DSC). Polymerization and folate conjugation was confirmed by FT-IR spectroscopy. The release kinetics of drug from the entrapped form was studied which showed initial burst release followed by sustained release due to swelling and increased cross-linking. In vitro cytotoxicity and cell uptake studies were conducted in human cervical cancer (HeLa) cell lines.
  
  
  CONCLUSIONS
  Results showed that curcumin entrapped folate conjugated cross-linked acrylic polymer (FA-CLAP) hydrogel showed higher cellular uptake than the non folate conjugated form. So this can be suggested as a better delivery system for site specific release of hydrophobic cancer drugs.
authors.forename: Jisha Jayadevan
authors.initials: JJ
authors.lastname: Pillai
authors.forename: Arun Kumar Theralikattu
authors.initials: AK
authors.lastname: Thulasidasan
authors.forename: Ruby John
authors.initials: RJ
authors.lastname: Anto
authors.forename: Devika Nandan
authors.initials: DN
authors.lastname: Chithralekha
authors.forename: Ashwanikumar
authors.initials: A
authors.lastname: Narayanan
authors.affiliation: Chemical Biology, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram-695 014, Poojappura, Kerala, India. gsvinod@rgcb.res.in.
authors.forename: Gopalakrishnapillai Sankaramangalam Vinod
authors.initials: GS
authors.lastname: Kumar
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry* / Q000493:pharmacokinetics* / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D003474:Curcumin / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D004337:Drug Carriers / Q000737:chemistry*; D005492:Folic Acid / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D053758:Nanoparticles / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry*
chemical_list: D000970:Antineoplastic Agents; D004337:Drug Carriers; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D011092:Polyethylene Glycols; D005492:Folic Acid; D003474:Curcumin