title: Development and molecular characterization of polymeric micro-nanofibrous scaffold of a defined 3-D niche for in vitro chemosensitivity analysis against acute myeloid leukemia cells.
abstract: Standard in vitro drug testing employs 2-D tissue culture plate systems to test anti-leukemic drugs against cell adhesion-mediated drug-resistant leukemic cells that harbor in 3-D bone marrow microenvironments. This drawback necessitates the fabrication of 3-D scaffolds that have cell adhesion-mediated drug-resistant properties similar to in vivo niches. We therefore aimed at exploiting the known property of polyurethane (PU)/poly-L-lactic acid (PLLA) in forming a micro-nanofibrous structure to fabricate unique, not presented before, as far as we are aware, 3-D micro-nanofibrous scaffold composites using a thermally induced phase separation technique. Among the different combinations of PU/PLLA composites generated, the unique PU/PLLA 60:40 composite displayed micro-nanofibrous morphology similar to decellularized bone marrow with increased protein and fibronectin adsorption. Culturing of acute myeloid leukemia (AML) KG1a cells in FN-coated PU/PLLA 60:40 shows increased cell adhesion and cell adhesion-mediated drug resistance to the drugs cytarabine and daunorubicin without changing the original CD34(+)/CD38(-)/CD33(-) phenotype for 168 hours compared to fibronectin tissue culture plate systems. Molecularly, as seen in vivo, increased chemoresistance is associated with the upregulation of anti-apoptotic Bcl2 and the cell cycle regulatory protein p27(Kip1) leading to cell growth arrest. Abrogation of Bcl2 activity by the Bcl2-specific inhibitor ABT 737 led to cell death in the presence of both cytarabine and daunorubicin, demonstrating that the cell adhesion-mediated drug resistance induced by Bcl2 and p27(Kip1) in the scaffold was similar to that seen in vivo. These results thus show the utility of a platform technology, wherein drug testing can be performed before administering to patients without the necessity for stromal cells.
authors.affiliation: Amrita Centre for Nanosciences and Molecular Medicine, Amrita Vishwa Vidyapeetham University, Kerala, India.
authors.forename: Maya S
authors.initials: MS
authors.lastname: Nair
authors.affiliation: Amrita Centre for Nanosciences and Molecular Medicine, Amrita Vishwa Vidyapeetham University, Kerala, India.
authors.forename: Ullas
authors.initials: U
authors.lastname: Mony
authors.affiliation: Amrita Centre for Nanosciences and Molecular Medicine, Amrita Vishwa Vidyapeetham University, Kerala, India.
authors.forename: Deepthy
authors.initials: D
authors.lastname: Menon
authors.affiliation: Amrita Centre for Nanosciences and Molecular Medicine, Amrita Vishwa Vidyapeetham University, Kerala, India.
authors.forename: Manzoor
authors.initials: M
authors.lastname: Koyakutty
authors.affiliation: Department of Oncology, Amrita Institute of Medical Sciences and Research Centre, Amrita Vishwa Vidyapeetham University, Kerala, India.
authors.forename: Neeraj
authors.initials: N
authors.lastname: Sidharthan
authors.affiliation: Department of Oncology, Amrita Institute of Medical Sciences and Research Centre, Amrita Vishwa Vidyapeetham University, Kerala, India.
authors.forename: Keechilat
authors.initials: K
authors.lastname: Pavithran
authors.affiliation: Amrita Centre for Nanosciences and Molecular Medicine, Amrita Vishwa Vidyapeetham University, Kerala, India.
authors.forename: Shantikumar V
authors.initials: SV
authors.lastname: Nair
authors.affiliation: Amrita Centre for Nanosciences and Molecular Medicine, Amrita Vishwa Vidyapeetham University, Kerala, India.
authors.forename: Krishnakumar N
authors.initials: KN
authors.lastname: Menon
mesh_terms: D001713:Biphenyl Compounds / Q000494:pharmacology; D002448:Cell Adhesion / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D003561:Cytarabine / Q000494:pharmacology; D003630:Daunorubicin / Q000494:pharmacology; D019008:Drug Resistance, Neoplasm / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor / Q000295:instrumentation / Q000379:methods*; D005353:Fibronectins / Q000737:chemistry; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry*; D015470:Leukemia, Myeloid, Acute / Q000188:drug therapy* / Q000473:pathology; D053761:Nanocomposites / Q000737:chemistry*; D057139:Nanofibers / Q000737:chemistry; D009596:Nitrophenols / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D011091:Polyesters; D011108:Polymers / Q000737:chemistry*; D011140:Polyurethanes / Q000737:chemistry*; D013449:Sulfonamides / Q000494:pharmacology; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: C501332:ABT-737; D001713:Biphenyl Compounds; D005353:Fibronectins; D009596:Nitrophenols; D010879:Piperazines; D011091:Polyesters; D011108:Polymers; D011140:Polyurethanes; D013449:Sulfonamides; D003561:Cytarabine; D019344:Lactic Acid; C033616:poly(lactide); D003630:Daunorubicin
keywords: Bcl2; cell adhesion-mediated drug resistance; cytarabine; daunorubicin; p27Kip1