Fabrication by three‐phase emulsification of pellicular adsorbents customised for liquid fluidised bed adsorption of bioproducts

Jahanshahi, Mohsen; Pacek, Andrzej W.; Nienow, Alvin W.; Lyddiatt, Andrew

doi:10.1002/jctb.907

Cited by 28 publications

(13 citation statements)

References 29 publications

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“…Particle size decreases to a value of 352.50 nm when the volume ratio of CS/TPP is increased to 25:12. This narrow particle size distribution suggests a better ionic interaction [30] between CS and TPP at this ratio, leading to an enhanced degree of crosslinking. The particle size was then shown to increase to 506.53 nm with increased in a volume ratio of CS/TPP to 25:15.…”

Section: Particle Size Pdi and Zeta Potentialmentioning

confidence: 94%

Self-Assembled Chitosan Nanoparticles for Percutaneous Delivery of Caffeine: Preparation, Characterization and in Vitro Release Studies

et al. 2018

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Objective: Chitosan (CS)-tripolyphosphate (TPP)-nanoparticles (NPs) have been extensively studied during the past few decades due to their wellrecognized applicability in various fields. The present study attempts to optimise the development of these nanoparticles to enhance the percutaneous delivery of caffeine.Methods: CS-TPP-NPs were prepared via ionic cross-linking of CS and TPP and were characterized. The influence of several formulation conditions (CS: TPP mass ratio and concentration of caffeine) and process parameters (stirring speed, stirring time and ultra-sonication time) on the colloidal characteristics of CS-TPP-NPs were investigated and the resulting nanoparticles were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and x-ray diffraction (XRD) analyses. Physicochemical properties, including particle size, zeta potential and polydispersity index (PDI) were examined, and in vitro release studies were conducted to ascertain the release profile of caffeine from the nanoparticles. In addition, the colloidal stability of the prepared NPs was also assessed on storage.Results: Process parameters appeared to exert a significant effect on the physicochemical characteristics of the CS-TPP-NPs. The CS-TPP-NPs prepared under optimum conditions (CS concentration of 0.2 mg/ml, CS: TPP volume ratio of 25:12 ml, stirred at 700 rpm for 60 min, with 0.97 mg/ml caffeine concentration and treatment with low ultra-sonication for 30 min) had shown a mean particle size of ~143.43±1.69 nm, zeta potential of+43.13±1.10 mV, PDI of ~0.30±0.01. A drug loading capacity and encapsulation efficiency of 48.89% and 60.69%, respectively, were obtained. Cumulative release study for drug-loaded CS-NPs was significantly (p<0.001, paired t-test) higher (58.7% caffeine released) compared to control formulation (41.5% caffeine released) after 72 h. Stability studies conducted for 28 d showed that caffeine-loaded CS-NPs degraded much quicker when stored at 25 ⁰C than 4 ⁰C. It was also noted that caffeine-loaded CS-NPs in the freeze-dried form were unstable as the surface charge of nanoparticles dropped from positive zeta potential to-3.55 mV within 2 d at 4 ⁰C and at 25 ⁰C, surface charge dropped to-3.16 mV within 14 d of the experiment. Conclusion:Chitosan (CS)-tripolyphosphate (TPP)-nanoparticles (NPs) appear to be a promising strategy to achieve sustained percutaneous delivery of caffeine.

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Section: Particle Size Pdi and Zeta Potentialmentioning

confidence: 94%

Self-Assembled Chitosan Nanoparticles for Percutaneous Delivery of Caffeine: Preparation, Characterization and in Vitro Release Studies

et al. 2018

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“…Following functionalization with the appropriate chemistry a selective porous adsorbent can be produced for the purification of biomolecules both in packed beds and, after inclusion of densifiers, in fluidized beds [11]. The efficiency of purification depends both on macro-and microscopic properties of adsorbent.…”

Section: Introductionmentioning

confidence: 99%

“…Agarose-based adsorbents with defined particle size/size distribution, mechanical properties and internal structure can be manufactured by several methods including, i) pressing the gelling polymer through a membrane [1], ii) spray gelation [14], or iii) agitation-induced emulsification of agarose solution in mineral oil [11,15]. In this work, particles were manufactured using a high shear mixer in batch mode.…”

Section: Introductionmentioning

confidence: 99%

“…Particles must also be sufficiently strong to withstand a number of high intensity post-manufacturing processes such as functionalization, filtration, centrifugation, sieving, pumping and washing [13]. It is therefore crucial to gain an understanding of their mechanical properties and how these are affected by manufacturing/processing conditions.Agarose-based adsorbents with defined particle size/size distribution, mechanical properties and internal structure can be manufactured by several methods including, i) pressing the gelling polymer through a membrane [1], ii) spray gelation [14], or iii) agitation-induced emulsification of agarose solution in mineral oil [11,15]. In this work, particles were manufactured using a high shear mixer in batch mode.…”

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confidence: 99%

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Manufacturing of agarose-based chromatographic adsorbents – Effect of ionic strength and cooling conditions on particle structure and mechanical strength

Ioannidis

Bowen

Pacek

et al. 2012

Journal of Colloid and Interface Science

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The effect of ionic strength of agarose solution and quenching temperature of the emulsion on the structure and mechanical strength of agarose-based chromatographic adsorbents was investigated. Solutions of agarose containing different amounts of NaCl were emulsified at elevated temperature in mineral oil using a high-shear mixer. The hot emulsion was quenched at different temperatures leading to the gelation of agarose and formation of soft particles. Analysis of Atomic Force Microscopy (AFM) images of particle surfaces shows that pore size of particles increases with ionic strength and/or high quenching temperature. Additionally it has been found that the compressive strength of particles measured by micromanipulation also increases with ionic strength of the emulsion and/or high quenching temperature but these two parameters have practically no significant effect on the resulting particle size and /particle size distribution. Results from both characterization methods were compared with Sepharose 4B, a commercial agarose-based adsorbent. This is the first report examining the effect of ionic strength and cooling conditions during manufacturing, on the microstructure of micron-sized agarose beads for bioseparation.Keywords: agarose beads; microstructure; pore size; mechanical properties; AFM; micromanipulation 2 IntroductionAgarose is one of the two constituents of agar (the other being agaropectin) which is extracted from red algae [1]. It is a linear polysaccharide consisting of 1, 3-linked β-D-galactopyranose and 1, 4-linked 3, 6-anhydro-α-L-galactopyranose, while agaropectin is a more complicated polysaccharide containing sulphuric and uronic acid residues [2]. The gelation of agarose involves a change from a random coil in solution to a double helix in the initial stages of gelation and then to bundles of double helices in the final stage [3]. The gel is formed when an infinite extensive three-dimensional network of agarose fibres (consisting of helices) develops [4]. At this state the material is characterized by a co-continuous macroporous morphology with polymer-rich regions (fibres) and solvent-rich regions (pores holding water), and therefore the gelation can be interpreted as a phase separation [5].Because of its physical and chemical stability, neutral charge, hydrophilic character, open structure [6, 7] and biocompatibility, agarose has been extensively used in chromatographic separation of biomolecules [8], cell microencapsulation [9] and food additives [10]. Following functionalization with the appropriate chemistry a selective porous adsorbent can be produced for the purification of biomolecules both in packed beds and, after inclusion of densifiers, in fluidized beds [11]. The efficiency of purification depends both on macro-and microscopic properties of adsorbent. Macroscopic properties such as particle size/size distribution, shape and mechanical strength have a critical effect on throughput, pressure drop and mechanical stability of adsorbent [12]. Particles must also be sufficientl...

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“…On the other hand, RTDs were studied to determine liquid mixing and dispersion within the column (Amersham Biosciences, 1998, Jahanshahi et al, 2002Palsson et al, 2001;Levenspiel, 1972). These parameters were obtained by using equations 1 and 2 (Levenspiel, 1972;Najafpour, 2007;Jahanshai et al, 2003;Biazus et al, 2006).…”

Section: Measurements Of Rtdmentioning

confidence: 99%

Investigation of hydrodynamic parameters in a novel expanded bed configuration: local axial dispersion characterization and an empirical correlation study

Taheri

Jahanshahi

Mosavian

et al. 2012

Braz. J. Chem. Eng.

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-Study of liquid behavior in an expanded bed adsorption (EBA) system is important for understanding, modeling and predicting nanobioproduct/biomolecule adsorption performance in such processes. In this work, in order to analyze the local axial dispersion parameters, simple custom NBG (Nano Biotechnology Group) expanded bed columns with 10 and 26 mm inner diameter were modified by insertion of sampling holes. Based on this configuration, the particles and liquid can be withdrawn directly from various axial positions of the columns. Streamline DEAE particles were used as solid phase in this work. The effects of factors such as liquid velocity, viscosity, settled bed height and column diameter on the hydrodynamic parameters were investigated. Local bed voidages in different axial bed positions were measured by a direct procedure within the column with 26 mm diameter. Increasing trend of voidage with velocity at a certain position of the bed and with bed height at a certain degree of expansion was observed. Residence time distribution (RTD) analysis at various bed points showed approximately uniform hydrodynamic behavior in the column with 10 mm diameter while a decreasing trend of mixing/dispersion along the bed height at a certain degree of expansion was seen in the column with 26 mm diameter. Also lower mixing/dispersion occured in the smaller diameter column. Finally, a combination of two empirical correlations proposed by Richardson-Zaki and Tong-Sun was successfully employed for identification of the bed voidage at various bed heights (RSSE=99.9%). Among the empirical correlations presented in the literatures for variation of the axial dispersion coefficient, the Yun correlation gave good agreement with our experimental data (RSSE=87%) in this column.

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Fabrication by three‐phase emulsification of pellicular adsorbents customised for liquid fluidised bed adsorption of bioproducts

Cited by 28 publications

References 29 publications

Self-Assembled Chitosan Nanoparticles for Percutaneous Delivery of Caffeine: Preparation, Characterization and in Vitro Release Studies

Self-Assembled Chitosan Nanoparticles for Percutaneous Delivery of Caffeine: Preparation, Characterization and in Vitro Release Studies

Manufacturing of agarose-based chromatographic adsorbents – Effect of ionic strength and cooling conditions on particle structure and mechanical strength

Investigation of hydrodynamic parameters in a novel expanded bed configuration: local axial dispersion characterization and an empirical correlation study

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