Rheological properties of suspensions containing cross-linked starch nanoparticles prepared by spray and vacuum freeze drying methods
Highlights
► Starch nanoparticles were produced through spray drying and vacuum freeze drying. ► Rheological behavior of suspensions containing these two types StNPs was investigated. ► Suspensions contain spray dried StNPs showed lower viscosity within shear range tested. ► Suspensions contain freeze dried StNPs showed stronger shear thinning and thixotropic. ► Suspensions containing freeze dried starch StNPs showed stronger elastic structure.
Introduction
Starch nanoparticles (particle size 1–1000 nm) comprising starch molecules and various cross-linkers are new class of biomaterials (Rodrigues and Emeje, 2012, Simi and Emilia Abraham, 2007). They have excellent mechanical and inherent functional properties such as low/non toxicity, low immunogenicity and good biocompatibility. Because of this reason, these starch nanoparticles have drawn considerable attention in food (Arora & Padua, 2010), medicine (Santander-Ortega et al., 2010), textile (Vigneshwaran et al., 2006), and biotechnology fields (Xiao et al., 2005). These starch nanoparticles have been regarded as highly valuable for their potential application as drug carrier materials in pharmaceutical industry (Jain et al., 2008, Kumari and Rani, 2011, Malam et al., 2011, Mohanraj and Chen, 2006).
Physical methods such as precipitation (Ma, Jian, Chang, & Yu, 2008) and microfluidization (Liu, Wu, Chen, & Chang, 2009) can produce these starch nanoparticles. Similarly chemical methods such as emulsion polymerization (Wang, Liu, & Pope, 2003) and emulsion cross-linking (Jain et al., 2008) can be used to produce these nanoparticles. Among these methods, emulsion cross-linking has been applied more commonly to manufacture various starch nanoparticles (Agnihotri et al., 2004, Bodnar et al., 2006). The emulsion cross-linking method has become the method of choice because it is easy to carry out and the yield of the nanoparticles is fairly high. When high pressure homogenizer is applied to produce the emulsions, this method is capable of reducing amount of surfactants used, lowering the particle size with ease, and increasing the productivity (Liu et al., 2009, Mcclements et al., 2007).
When the nanoparticles are produced, it is necessary to remove the solvent, especially water by drying. The drying step is necessary to extend the storage life of the starch nanoparticles and to reduce the volume/weight of the final product. So far, spray drying and vacuum freeze drying are the two most commonly used methods for removing the water in the production of nanoparticles (Jain et al., 2008, Patil et al., 2010). The particle temperature (during drying) and the rate of water removal are quite different in these two drying systems. Because of these reasons, the final particles produced by using these two drying systems are quite different, especially in appearance, particle size, degree of crystallization, and re-dispersibility. Among these properties, re-dispersibility of particles can have remarkable influence or impact on their application (Kho & Hadinoto, 2010). The rheological properties can be excellent indicators of the re-dispersing behavior of suspensions containing these starch nanoparticles (Kimura et al., 2011).
The rheological properties, which include the continuous shear viscosity and storage or loss modulus, vary with shear rate, temperature, frequency and time. The rheological properties of suspensions containing nanoparticles are investigated and reported. For example, the rheological features of suspensions containing chitosan–sodium tripolyphosphate nanoparticles (Li & Huang, 2012), iron nanoparticles (Borin, Zubarev, Chirikov, Müller, & Odenbach, 2011), cell-wall particle (Day, Xu, Øiseth, Lundin, & Hemar, 2010) and silica nanoparticles (Triebel & Münstedt, 2011) have been reported. However, to the best of our knowledge, there are no publications reporting the effect of drying methods (used to produce nanoparticles) on the rheological properties of suspension containing starch nanoparticles. Therefore, the objective of this study was to investigate the effect of two drying methods (vacuum freeze drying and spray drying) on the rheological properties of suspensions containing these starch nanoparticles. The continuous shear viscosity tests are carried out to determine the effect of shear rate and temperature on apparent viscosity of the suspensions. The dynamic rheological tests are carried out to investigate the effect of frequency on the elastic and loss modulus and phase angle. The creep recovery test is carried out to determine the extent of recovery (from deformation) of the suspensions from applied stress. The Cross model is used to represent the shear dependent viscosity while the Power Law type equations are used to represent the frequency dependence of storage and loss modulus. The creep-recovery data are modeled using Burger's model which contains Maxwell and Kelvin models in series.
Section snippets
Materials
Soluble starch was purchased from Beijing Aoboxing Biological Technique Company (Beijing, China). Sodium chloride, sodium hydroxide, cyclohexane, acetone and acetic acid were provided by Beijing Chemical Company (Beijing, China). Tween-80 and Span-80 were purchased from Tianjing Fuchen Chemical Company (Tianjing, China). Sodium trimetaphosphate (STMP) was obtained from Tianjing Dengfeng Chemical Company (Tianjing, China). All of these reagents were of analytical grade and used without further
Continuous shear viscosity properties
In order to describe the variation in the flow properties of suspension containing cross-linked starch nanoparticles (obtained by spray and freeze drying as described in Section 2.3) under continuous shear, the Cross model (Eq. (1)) is used (Susan-Resiga, Bica, & Vékás, 2010).Here η is the apparent viscosity (Pa s), η∞ is the viscosity at infinite shear rate (Pa s), η0 is the viscosity at zero shear rate, c is the consistency (s), is the shear rate (s−1), and m is the flow
Conclusions
The rheological characteristics of suspensions containing vacuum freeze dried and spray dried starch nanoparticles was investigated. The suspensions containing vacuum freeze dried nanoparticles showed higher apparent viscosity compared to the suspensions containing spray dried nanoparticles within 0.1–100 s−1 shear rate and 25–90 °C temperature range. The suspensions containing vacuum freeze dried particles had greater propensity to undergo shear thinning compared to the suspensions containing
Acknowledgments
This research was supported by National Natural Science Foundation of China (31000813), Chinese Universities Scientific Fund (2012QJ009), High Technology Research and Development Program of China (2011AA100802), and Commonweal Guild Agricultural Scientific Research Project of China (201003077).
References (33)
- et al.
Recent advances on chitosan-based micro- and nanoparticles in drug delivery
Journal of Controlled Release
(2004) - et al.
Ferrofluid with clustered iron nanoparticles: Slow relaxation of rheological properties under joint action of shear flow and magnetic field
Journal of Magnetism and Magnetic Materials
(2011) - et al.
Dynamic rheological properties of plant cell-wall particle dispersions
Colloids and Surfaces B: Biointerfaces
(2010) - et al.
Effective insulin delivery using starch nanoparticles as a potential trans-nasal mucoadhesive carrier
European Journal of Pharmaceutics and Biopharmaceutics
(2008) - et al.
Creep and recovery of polypropylene/carbon nanotube composites
International Journal of Plasticity
(2011) - et al.
Aqueous re-dispersibility characterization of spray-dried hollow spherical silica nano-aggregates
Powder Technology
(2010) - et al.
Rheological properties of chitosan–tripolyphosphate complexes: From suspensions to microgels
Carbohydrate Polymers
(2012) - et al.
Transitional properties of starch colloid with particle size reduction from microto nanometer
Journal of Colloid and Interface Science
(2009) - et al.
Preparation and investigation of a cross-linked hyaluronan nanoparticles system
Carbohydrate Polymers
(2011) - et al.
Recent applications of starch derivatives in nanodrug delivery
Carbohydrate Polymers
(2012)
Nanoparticles made from novel starch derivatives for transdermal drug delivery
Journal of Controlled Release
Preparation of starch-based nanoparticles through high-pressure homogenization and miniemulsion cross-linking: Influence of various process parameters on particle size and stability
Carbohydrate Polymers
The effect of annealing and cryoprotectants on the properties of vacuum-freeze dried starch nanoparticles
Carbohydrate Polymers
Flow behaviour of extremely bidisperse magnetizable fluids
Journal of Magnetism and Magnetic Materials
Temperature dependence of rheological properties of poly(methyl methacrylate) filled with silica nanoparticles
Polymer
A novel one-pot ‘green’ synthesis of stable silver nanoparticles using soluble starch
Carbohydrate Research
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These authors contributed equally to this work.