Content area
Full Text
Received Apr 4, 2017; Revised Jun 2, 2017; Accepted Jun 19, 2017
This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
1. Introduction
Bone marrow is currently regarded as the main source of mesenchymal stem cells (MSC) as therapy for bone deficiencies [1]. However, the process of collecting bone marrow derived mesenchymal cells is invasive to donors and patients, and it can cause complications such as chronic pain, bleeding, and infection, thereby limiting the wide application of bone marrow-derived MSC in clinical settings [2]. Human umbilical cord blood contains many immature stem/progenitor cells with multilineage differentiation and extensive proliferation capacity and is considered an alternative source for stem cell-based therapies [1, 3]. Similar to bone marrow-derived MSC, human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSC) also possess activity for immune modulation and tumor tropism [4, 5]. In addition, human hUCB-MSC can be obtained after full-term delivery of newborns, and the process of collecting hUCB-MSC is noninvasive and painless and does not harm the mother or infant. hUCB-MSC can be cryogenically stored, thawed, and expanded for therapeutic uses [6, 7], providing a convenient solution for the cells needed in therapy.
With the emerging role of hUCB-MSC as potential gene and cell therapy vehicles, there is an increasing need for effective gene delivery systems to modify such cells. The success of gene delivery is largely dependent on the development of a carrier that can efficiently transfer a target gene to hUCB-MSC with clinical safety and minimal toxicity [8]. Nonviral gene carriers are receiving increasing attention for the delivery of gene-based therapeutics because of their safety, flexibility in chemical design, and large capacity for vector delivery [9, 10]. The cationic polymer polyethylenimine (PEI) has been widely used for nonviral transfection and has an advantage...