2215 ISSN 1229-9197 (print version) ISSN 1875-0052 (electronic version) Fibers and Polymers 2020, Vol.21, No.10, 2215-2223 Surface-functionalized Electrospun Polycaprolactone Fiber for Culturing Stem Cell from Human Exfoliated Deciduous Teeth Culture Jirasak Jitpibull 1 , Thammasit Vongsetskul 1,2 * , Hathaitip Sritanaudomchai 3 , and Nathaphon Tangjit 4 1 School of Materials Science and Innovation, Faculty of Science, Mahidol University, Nakhon Pathom 73170, Thailand 2 Department of Chemistry, Faculty of Science, Mahidol University, Bangkok 10400, Thailand 3 Department of Oral Biology, Faculty of Dentistry, Mahidol University, Bangkok 10400, Thailand 4 Department of Orthodontics, Faculty of Dentistry, Mahidol University, Bangkok 10400, Thailand (Received October 23, 2019; Revised February 4, 2020; Accepted February 10, 2020) Abstract: Smooth and bead-free polycaprolactone (PCL) fiber with average diameter of 2.8 micron and pore size of 25 micron were spun from 17 % w/w PCL dissolved in a chloroform:methyl alcohol mixture (3:1 by volume) at 20 kV, a fiber collection distance of 15 cm, a nozzle diameter of 0.9 mm, and 2 ml/h for 5 hours. Then, the fiber surface was immobilized by gelatin (GE), coated by hyaluronic acid (HA), and done by both processes to obtain GE-PCL, HA-PCL, and HA-GE-PCL, respectively. The treated fiber was completely wet by water, whereas the PCL fiber was not. GE improved thermal stability, while HA increased the tensile strength and elastic moduli of the fiber. Both GE and HA reduced their elongations at break. Stem cells from human deciduous teeth (SHED) were chosen to study their proliferation on the fiber, which was exponentially in the following order: GE-PCL > HA-GE-PCL > HA-PCL > PCL. Keywords: Fiber, Gelatin, Human exfoliated deciduous tooth, Polycaprolactone, Tissue engineering Introduction Cleft lip and cleft palate (CLP), a gap in upper lip and/or roof of the mouth, are deformity caused by the lack of tissue fusion above the lip [1]. Prevalence of this deformity is 0.69 % of live births around the world [2]. CLP is usually found in mothers with drug addiction, low levels of folic acid, or diabetes [3-5]. CLP cause various problems such as esthetic, food uptake, hearing, and infection at ear nose and throat [6,7]. The series of surgery are commonly used for treating CLP. The surgery can be operated at ages from 3 months to 11 years to repair the defect of alveolar bone by grafting it to allow the teeth eruption [2]. Various natural bone materials were used for bone grafting such as autograft, allograft, and xenograft materials, which may cause pain and material rejection by patients. Thus, the synthetic materials are used to repair the deformity of alveolar bone [8]. However, the compatibility between these synthetic materials and human tissue is a problem. Therefore, tissue engineering is expected to solve this problem by constructing scaffolds to help the formation of bones from patient’s owned cells. Generally, scaffolds should support cell activities and act as a template for guiding cell’s growth [9]. To achieve this goal, scaffolds must be biocompatible, biodegradable, highly porous, and strong enough during bone growth period [10]. Among several material structures, electrospun fiber is a good candidate because surface of electrospun fiber can mimic the extra cellular matrix (ECM) [11-13] and its mechanical properties can be tuned [14]. Polycaprolactone (PCL), a synthetic biocompatible polymer, is chosen because PCL meets the minimum requirement to be used in fabricating scaffolds such as good mechanical performance [15,16], biocompatibility, and biodegradability [17,18]. In this work, the PCL ultrafine fiber will be produced and their surface will be modified to make it hydrophilic to promote cell proliferation, cell attachment, and cells differentiation because protein is highly absorbed on hydrophilic surface. PCL surface will be either treated chemically or layer-by- layer coated with biopolymers. Hyaluronic acid (HA) is a natural polysaccharide in ECM [19]. HA is composed of two monomers, N-acetyl-D- glucosamine and D-gluconic acid [20]. HA is used in tissue engineering due to its no toxicity, non-immunogenicity, and biodegradability [21]. HA is widely used to treat surface of polymer scaffold to improve surface hydrophilicity and scaffold’s mechanical properties [22,23]. Gelatin (GE), a hydrophilic protein from collagen, is also widely used in tissue engineering to promote cell proliferation [24-28]. GE can be mixed with PCL solution before spinning [29], coated [30], or immobilized [31-33] on scaffold surface. Thus, in this work, we developed electrospun PCL fiber- based scaffolds which were treated by GE, HA, and both to improve their biocompatibilities with stem cells from human exfoliated teeth (SHED) cells for the first time. Here, SHED cells were collected from the pulp of primary teeth because they are less traumatic than stem cells from other sources, have a high proliferation capacity [34], and can differentiate to various types of cells, especially osteoblast cells for bone tissue engineering [35]. After surface treatments, scaffolds were studied by scanning electron microscope (SEM), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), thermogravimetric analyzer (TGA), homemade contact angle goniometer, dynamic mechanical *Corresponding author: thammasit.von@mahidol.ac.th DOI 10.1007/s12221-020-1147-3