title: Selection and optimization of nano-formulation of P-glycoprotein inhibitor for reversal of doxorubicin resistance in COLO205 cells.
abstract: OBJECTIVE
  The prime objective of current work was to develop a strategy for preparation of combinational nano-formulation for reversal of drug resistance.
  
  
  METHODS
  As a model system, doxorubicin (DOX)-resistant COLO205 cells were developed and validated. From co-treatment studies with DOX, curcumin was selected as it reversed DOX-resistance at lowest concentration. In an attempt to increase its solubility, curcumin was encapsulated into hydroxypropyl-β-cyclodextrin (HP-β-CD). Here, we propose that presence of stabilizer overcomes its low encapsulation efficiency. Thus, we evaluated curcumin encapsulation in HP-β-CD in presence of different stabilizers and organic solvents. Finally, the effect of nanocurcumin with liposomal DOX was studied for reversal of resistance in COLO205 cells.
  
  
  RESULTS
  In the process encapsulation, selective optimization of organic solvent by freeze-drying was found to be appropriate among other methods. From optimization studies with different organic solvent (acetone and dichloromethane) and stabilizer [polyvinyl alcohol (PVA) and Pluronics], HP-β-CD-encapsulated curcumin prepared using acetone in PVA-stabilized dispersion increased encapsulation (60%) with size of ~40 nm. Prepared nano-curcumin reversed the DOX resistance effectively in combination with liposomal DOX.
  
  
  CONCLUSIONS
  Curcumin reversed DOX resistance in COLO205 cells at low concentration and enhanced curcumin encapsulation in HP-β-CD was noted in presence of PVA. Further, it was observed that prepared HP-β-CD-encapsulated curcumin is equi-efficacious to nano-dispersed curcumin.
authors.affiliation: School of Biological Sciences, National Institute of Science Education and Research (NISER, HBNI), Khurda, India.
authors.forename: Tapan K
authors.initials: TK
authors.lastname: Dash
authors.affiliation: School of Biological Sciences, National Institute of Science Education and Research (NISER, HBNI), Khurda, India.
authors.forename: Venkata Sai Badireenath
authors.identifier: http://orcid.org/0000-0003-3699-7490
authors.initials: VSB
authors.lastname: Konkimalla
mesh_terms: D000073738:2-Hydroxypropyl-beta-cyclodextrin / Q000737:chemistry; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors; D000230:Adenocarcinoma / Q000188:drug therapy / Q000473:pathology; D000903:Antibiotics, Antineoplastic / Q000008:administration & dosage / Q000494:pharmacology; D045744:Cell Line, Tumor; D002626:Chemistry, Pharmaceutical / Q000379:methods; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000473:pathology; D003474:Curcumin / Q000008:administration & dosage / Q000494:pharmacology*; D004317:Doxorubicin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D019008:Drug Resistance, Neoplasm; D005079:Excipients / Q000737:chemistry; D006801:Humans; D053758:Nanoparticles; D010316:Particle Size; D011092:Polyethylene Glycols / Q000008:administration & dosage / Q000494:pharmacology; D012995:Solubility; D012997:Solvents / Q000737:chemistry
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000903:Antibiotics, Antineoplastic; D005079:Excipients; D012997:Solvents; C506643:liposomal doxorubicin; D000073738:2-Hydroxypropyl-beta-cyclodextrin; D011092:Polyethylene Glycols; D004317:Doxorubicin; D003474:Curcumin
keywords: drug resistance; encapsulation efficiency; freeze-drying; hydroxypropyl-β-cyclodextrin; nano-curcumin