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.

3D culture enhances chemoresistance of ALL Jurkat cell line by increasing DDR1 expression

“…Hematological malignancy of acute leukemia is highly heterogeneous. At present, there are no standardized chemotherapy regimens for acute lymphoblastic leukemia (ALL) bone marrow microenvironment (1), with specific three dimensional (3D) structure, can support the growth of leukemia cells as well as protect them from chemotherapy drug induced death (2–4). 3D scaffold needs some properties to better mimic the bone marrow environment, such as adequate pore size, interconnected pores and high surface area, which will facilitate cells penetration and the formation of cellular associations (5).…”

Advancement of Scaffold-Based 3D Cellular Models in Cancer Tissue Engineering: An Update

“…Nair et al developed a polyurethane (PU)/poly-Llactic acid (PLLA) micro-nanofibrous scaffold by a thermally induced phase separation technique. Acute Myeloid Leukemia (AML) cells cultured in the scaffold showed an increased cell adhesion and drug resistance (65). Phan Lai et al used hybrid 3D chitosan-alginate fibre scaffolds for the in vitro evaluation of tumour−stromal−T cell interactions.…”

Drug discovery and therapeutic delivery for the treatment of B and T cell tumors

“…Because many of the elements of xenografts are out of the researcher’s control, three dimensional in vitro models of hematological malignancies have been developed for AML 204, 205 , follicular lymphoma 206, 207 , B cell lymphoma 208, 209 , and multiple myeloma 210–214 . With the modularity of tissue engineering, these 3D models are highly adaptable to be disease specific.…”

“…With the modularity of tissue engineering, these 3D models are highly adaptable to be disease specific. While culturing techniques like using the hanging drop method for the formation of aggregates 207, 215 required little engineering for microenvironment development, microenvironment tailoring has been achieved through manipulation of biomaterial stiffness 209 , strength 212 , integrin ligand presentation 208, 209 , inclusion of stromal cell support 204, 213 , and morphology 205 . Even though tailored tissue engineered constructs are over-simplifications of the tumor microenvironment, the presence of these 3D structures in cancer drug trials has been shown to produce different responses when compared to traditional 2D cell culture 204, 206–209, 212 .…”