Naznin Sultana
Universiti Teknologi Malaysia
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Featured researches published by Naznin Sultana.
Biofabrication | 2012
Naznin Sultana; M Wang
Tissue engineering combines living cells with biodegradable materials and/or bioactive components. Composite scaffolds containing biodegradable polymers and nanosized osteoconductive bioceramic with suitable properties are promising for bone tissue regeneration. In this paper, based on blending two biodegradable and biocompatible polymers, namely poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and poly(L-lactic acid) (PLLA) with incorporated nano hydroxyapatite (HA), three-dimensional composite scaffolds with controlled microstructures and an interconnected porous structure, together with high porosity, were fabricated using an emulsion freezing/freeze-drying technique. The influence of various parameters involved in the emulsion freezing/freeze-drying technique was studied for the fabrication of good-quality polymer scaffolds based on PHBV polymers. The morphology, mechanical properties and crystallinity of PHBV/PLLA and HA in PHBV/PLLA composite scaffolds and PHBV polymer scaffolds were studied. The scaffolds were coated with collagen in order to improve wettability. During in vitro biological evaluation study, it was observed that SaOS-2 cells had high attachment on collagen-coated scaffolds. Significant improvement in cell proliferation and alkaline phosphatase activity for HA-incorporated composite scaffolds was observed due to the incorporation of HA. After 3 and 7 days of culture on all scaffolds, SaOS-2 cells also had normal morphology and growth. These results indicated that PHBV/PLLA-based scaffolds fabricated via an emulsion freezing/freeze-drying technique were favorable sites for osteoblastic cells and are promising for the applications of bone tissue engineering.
Journal of Nanomaterials | 2012
Naznin Sultana; Tareef Hayat Khan
This paper investigated the long-term in vitro degradation properties of scaffolds based on biodegradable polymers and osteoconductive bioceramic/polymer composite materials for the application of bone tissue engineering. The threedimensional porous scaffolds were fabricated using emulsion-freezing/freeze-drying technique using poly(hydroxybutyrate-cohydroxyvalerate) (PHBV) which is a natural biodegradable and biocompatible polymer. Nanosized hydroxyapatite (nHA) particles were successfully incorporated into the PHBV scaffolds to render the scaffolds osteoconductive. The PHBV and nHA/PHBV scaffolds were systematically evaluated using various techniques in terms of mechanical strength, porosity, porous morphology, and in vitro degradation. PHBV and nHA/PHBV scaffolds degraded over time in phosphate-buffered saline at 37°C. PHBV polymer scaffolds exhibited slow molecular weight loss and weight loss in the in vitro physiological environment. Accelerated weight loss was observed in nHA incorporated PHBV composite scaffolds. An increasing trend of crystallinity was observed during the initial period of degradation time. The compressive properties decreased more than 40% after 5-month in vitro degradation. Together with interconnected pores, high porosity, suitable mechanical properties, and slow degradation profile obtained from long-term degradation studies, the PHBV scaffolds and osteoconductive nHA/PHBV composite scaffolds showed promises for bone tissue engineering application.
Journal of Experimental Nanoscience | 2008
Naznin Sultana; M Wang
Composite scaffolds made of PHBV/PLLA blends and nano-sized hydroxyapatite (HA) particles can be useful for bone tissue engineering as different blends of PHBV with PLLA should have higher degradation rates than PHBV itself and scaffolds containing bioactive HA particles will provide desired osteoconductivity. In this investigation, composite scaffolds were produced via an emulsion freezing/freeze-drying process and subsequently characterised using several techniques. Highly porous and interconnected scaffolds with porosity greater than 70% could be made. It was found that the crystallinity of PHBV in the scaffolds was decreased due to blending with the PLLA polymer, which is beneficial for the faster degradation of the scaffolds in vitro and in vivo. It was shown that the incorporation of HA nanoparticles enhanced compressive mechanical properties of scaffolds.
Journal of Nanomaterials | 2014
Mohd Izzat Hassan; Naznin Sultana; Salehhuddin Hamdan
Electrospinning is useful for fabricating nanofibrous structure with different composition and morphologies. It offers great advantages through its geometrical structure and biomimetic property, which can provide a suitable environmental site for cell growth. The fiber diameter is entangled by the concentration of PCL with some adjustment of parameters during electrospinning process. PCL with lower concentration had bead structure while higher concentration had smooth fiber. The incorporation of nanoparticle hydroxyapatite (nHA) into poly(e-caprolactone) fiber was studied. The fiber diameter of PCL was increased with the addition of nHA. Composition of fiber at lower concentrations of PCL and nHA into the polymer produced fiber with a homogenous distribution of nHA in PCL fiber with less agglomeration. The immersion of PCL/nHA fiber in simulated body fluid (SBF) had bonelike apatite layer on its surface while PCL showed no results. PCL/nHA showed high water uptake and had improved wettability compared to PCL alone, suggesting that PCL/nHA fibers were more hydrophilic than PCL fiber.
Journal of Nanomaterials | 2013
Naznin Sultana; Tareef Hayat Khan
Water uptake characteristics of poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV-) based composite tissue engineering (TE) scaffolds incorporating nanosized hydroxyapatite (nHA) have been investigated. The water absorption of these composite scaffolds obeyed the classical diffusion theory for the initial period of time. The diffusion coefficients of the composite scaffolds during the water absorption weremuch faster than those for the nonporous thin films, suggesting that the water uptake process depends on the presence of porosity and porous microstructure of the composite scaffolds. The incorporation of nHA increased the water uptake of both the composite scaffolds and thin films. It was also observed that the equilibrium uptake increased with the incorporation of nHA. This increase in the water uptake was largely due to the nHA particle aggregates in the microstructure of both composite scaffolds and thin films. The activation energy for diffusion was also determined using the Arrhenius equation for both porous scaffolds and thin films and the results suggested that the activation energy for scaffolds was lower than that for thin films.
Journal of Nanomaterials | 2013
Fatemeh Roozbahani; Naznin Sultana; Ahmad Fauzi Ismail; Hamed Nouparvar
Recently, nanofibrous scaffolds have been used in the field of biomedical engineering as wound dressings, tissue engineering scaffolds, and drug delivery applications. The electrospun nanofibrous scaffolds can be used as carriers for several types of drugs, genes, and growth factors. PCL is one of the most commonly applied synthetic polymers for medical use because of its biocompatibility and slow biodegradability. PCL is hydrophobic and has no cell recognition sites on its structure. Electrospinning of chitosan and PCL blend was investigated in formic acid/acetic acid as the solvent with different PCL/chitosan ratios. High viscosity of chitosan solutions makes difficulties in the electrospinning process. Strong hydrogen bonds in a 3D network in acidic condition prevent the movement of polymeric chains exposed to the electrical field. Consequently, the amount of chitosan in PCL/chitosan blend was limited and more challenging when the concentration of PCL increases. The treatment of chitosan in alkali condition under high temperature reduced its molecular weight. Longer treatment time further decreased the molecular weight of chitosan and hence its viscosity. Electrospinning of PCL/chitosan blend was possible at higher chitosan ratio, and SEM images showed a decrease in fiber diameter and narrower distribution with increase in the chitosan ratio.
Journal of Nanomaterials | 2014
Mohd Izzat Hassan; Tao Sun; Naznin Sultana
Tissue engineering fibrous scaffolds serve as three-dimensional (3D) environmental framework by mimicking the extracellular matrix (ECM) for cells to grow. Biodegradable polycaprolactone (PCL) microfibers were fabricated to mimic the ECM as a scaffold with 7.5% (w/v) and 12.5% (w/v) concentrations. Lower PCL concentration of 7.5% (w/v) resulted in microfibers with bead defects. The average diameter of fibers increased at higher voltage and the distance of tip to collector. Further investigation was performed by the incorporation of nanosized hydroxyapatite (nHA) into microfibers. The incorporation of 10% (w/w) nHA with 7.5% (w/v) PCL solution produced submicron sized beadless fibers. The microfibrous scaffolds were evaluated using various techniques. Biodegradable PCL and nHA/PCL could be promising for tissue engineering scaffold application.
Materials and Manufacturing Processes | 2015
Naznin Sultana; Masturah Mokhtar; Mohd Izzat Hassan; Rashid Mad Jin; Fatemeh Roozbahani; Tareef Hayat Khan
This article reports the fabrication of three-dimensional porous chitosan and hydroxyapatite (HA)/chitosan composite scaffolds by the thermally induced phase separation (TIPS) technique, for bone tissue engineering. Different amounts of HA nanoparticles (10%, 20%, and 30% g/g) were added to the chitosan solution to produce HA/chitosan composite scaffolds of varying compositions. The morphology and pore structure of the scaffolds vis-à-vis composition were characterized using scanning electron microscopy (SEM) and an energy dispersive X-ray (EDX). Both pure chitosan and HA/chitosan composite scaffolds were highly porous and had interconnected pores. The pore sizes ranged from several micrometers to a few hundred micrometers. The HA nanoparticles were well dispersed and physically coexisted with chitosan in the composite scaffolds. However, some agglomeration of HA nanoparticles was observed on the surface of pore walls when a relatively large amount of HA was used. The composite 3D scaffolds are very promising for use in bone tissue engineering application.
Journal of Nanomaterials | 2015
Lor Huai Chong; Mim Mim Lim; Naznin Sultana
Nanofibrous scaffolds were fabricated through blending of a synthetic polymer, polycaprolactone (PCL), and a natural polymer, gelatin (GE), using an electrospinning technique. Processing and solution parameters were optimized to determine the suitable properties of PCL/GE-based nanofibers. Several characterizations were conducted to determine surface morphology by scanning electron microscopy (SEM), wettability using water contact angle measurement, and chemical bonding analysis using attenuated total reflectance (ATR) of PCL/GE-based nanofibers. Experimental results showed that 14% (w/v) PCL/GE with a flow rate of 0.5 mL/h and 18 kV demonstrated suitable properties. This nanofiber was then further investigated for its in vitro degradation, drug loading (using a model drug, tetracycline hydrochloride), and antibacterial testing (using zone inhibition method).
Journal of Nanomaterials | 2014
Tao Sun; Tareef Hayat Khan; Naznin Sultana
Composite scaffolds based on biodegradable natural polymer and osteoconductive hydroxyapatite (HA) nanoparticles can be promising for a variety of tissue engineering (TE) applications. This study addressed the fabrication of three-dimensional (3D) porous composite scaffolds composed of HA and chitosan fabricated via thermally induced phase separation and freezedrying technique. The scaffolds produced were subsequently characterized in terms of microstructure, porosity, and mechanical property. In vitro degradation and in vitro biological evaluation were also investigated. The scaffolds were highly porous and had interconnected pore structures. The pore sizes ranged from several microns to a few hundred microns. The incorporated HA nanoparticles were well mixed and physically coexisted with chitosan in composite scaffold structures. The addition of 10% (w/w) HA nanoparticles to chitosan enhanced the compressive mechanical properties of composite scaffold compared to pure chitosan scaffold. In vitro degradation results in phosphate buffered saline (PBS) showed slower uptake properties of composite scaffolds. Moreover, the scaffolds showed positive response to mouse fibroblast L929 cells attachment. Overall, the findings suggest that HA/chitosan composite scaffolds could be suitable for TE applications.