Modeling of permeate flux and mass transfer resistances in the reclamation of molasses wastewater by a novel gas-sparged nanofiltration

Tejal Manish Patel,Kaushik Nath 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.10

A semi-empirical model has been applied to predict the permeate flux and mass transfer resistances duringthe cross flow nanofiltration of molasses wastewater in flat-sheet module. The model includes laminar flow regimeas well as flow in presence of gas sparging at two different gas velocities. Membrane hydraulic resistance (Rm), osmoticpressure resistance (Rosm) and the concentration polarization resistance (Rcp) were considered in series. The concentra-tion polarization resistance was correlated to the operating conditions, namely, the feed concentration, the trans-mem-brane pressure difference and the cross flow velocity for a selected range of experiments. There was an appreciablereduction of concentration polarization resistance Rcpsparin presence of gas sparging. Both the concentration polarizationresistance Rcplamand osmotic pressure resistance Rosm decreased with cross-flow velocity, but increased with feed con-centration and the operating pressure. Experimental and theoretical permeate flux values as a function of cross flowvelocity for both the cases, in the presence and absence of gas sparging, were also compared.

Improvement of osteogenic differentiation of bone human mesenchymal stem cells by fluid flow-assisted a cartridge device under perfusion culture

( Ki-taek Lim ),( Dinesh Patel ),( Sayan Deb Dutta ),( Keya Ganguly ),( Tejal Patel ) 한국농업기계학회 2021 한국농업기계학회 학술발표논문집 Vol.26 No.2

Human mesenchymal stem cells (hMSCs) have the potential to differentiate into different types of mesodermal tissues. In vitro proliferation and differentiation of hMSCs are necessary for bone regeneration in tissue engineering. The present study aimed to design and develop a fluid flow mechanically-assisted cartridge device to enhance the osteogenic differentiation of hMSCs. We used the fluorescence-activated cell-sorting method to analyze the multipotent properties of hMSCs and found that the cultured cells retained their stemness potential. We also evaluated the cell viabilities of the cultured cells via water-soluble tetrazolium salt 1 (WST-1) assay under different rates of flow (0.035, 0.21, and 0.35 mL/min) and static conditions and found that the cell growth rate was approximately 12% higher in the 0.035 mL/min flow condition than the other conditions. Moreover, the cultured cells were healthy and adhered properly to the culture substrate. Enhanced mineralization and alkaline phosphatase activity were also observed under different perfusion conditions compared to the static conditions, indicating that the applied conditions play important roles in the proliferation and differentiation of hMSCs. Furthermore, we determined the expression levels of osteogenesis-related genes, including the runt-related protein 2 (Runx2, 1.3-fold), collagen type I (Col1, 1.4-fold), osteopontin (OPN, 1.5-fold), and osteocalcin (OCN, 1.5-fold), under various perfusion vis-à-vis static conditions and found that they were significantly affected by the applied conditions. Furthermore, the fluorescence intensities of OCN and OPN osteogenic gene markers were found to be enhanced with 38% in the 0.035 mL/min flow condition compared to the control, indicating that it was a suitable condition for osteogenic differentiation. Taken together, the findings of this study reveal that the developed cartridge device promotes the proliferation and differentiation of hMSCs and can potentially be used in the field of tissue engineering.

Effect of Oroxylum indicum on intestinal motility in rodents

Joshi, Shrikant V.,Gandhi, Tejal R.,Vyas, Bhavin A.,Shah, Payal D.,Patel, Paras K.,Vyas, Heta G. 경희한의학연구센터 2012 Oriental Pharmacy and Experimental Medicine Vol.12 No.4

Oroxylum indicum is traditional herbal medicine in India, China and Japan used for its anti-diarrhoeal/anti-dysenteric activity, also found to be active against experimentally induced (DNBS induced) inflammatory bowel disease in rats with potential reduction in diarrhoea. It promotes us to evaluate effects of Oroxylum indicum on intestinal motility, both in vitro and in vivo, in rodents. Flavonoids rich fraction of O. indicum was obtained and the effect of extract on contraction of acetylcholine, barium chloride and electrical field stimulation was studied on isolated rabbit ileum. Anti-diarrhoeal activities were investigated using castor oil and magnesium sulphate-induced diarrhoeal models in mice. Effect on intestinal motility was studied using gastrointestinal motility and antienteropooling assay methods. Antimicrobial activity of extract was evaluated using disc diffusion assay method. Extract inhibited the contractions induced by acetylcholine, barium chloride and electrical field stimulation. Verapamil potentiates inhibitory effect of extract. Extract showed significant and dose-dependent antidiarrhoeal effect devoid of altering gastrointestinal motility in normal animals. It also inhibited the microbial growth in disc diffusion assay method. Extract normalized intestinal motility altered by inflammatory stimulus and possesses antidiarrhoeal activity. Alteration of intestinal motility may involve modification in L-type $Ca^{2+}$ channels.

Improvement of dissolution rate of tacrolimus by solid dispersion technique

Shital S. Panchal,Tejal A. Mehta,Pranav V. Patel 한국약제학회 2013 Journal of Pharmaceutical Investigation Vol.43 No.1

Tacrolimus has a poor solubility in water ranging from 4 to 12 lg mL-1. The mean bioavailability is *21 %.The present study was carried out with a view to enhance the dissolution rate of poorly water-soluble drug tacrolimus using Gelucire 44/14 and Gelucire 50/13 as carriers and lactose monohydrate as an adsorbent. A combination of melt and adsorption techniques was employed for the preparation of solid dispersions (SD) to make final product easy for handling. Phase solubility study was conducted to evaluate the effect of carriers on aqueous solubility of tacrolimus. In order to elucidate the mechanism of dissolution enhancement, solid state characteristics were investigated using Fourier transform infrared spectroscopy,differential scanning calorimetry and powder X-ray diffraction. Mathematical modeling of in vitro dissolution data indicated the best fitting with Korsemeyer–Peppas model and the drug release kinetics primarily as Fickian/anomalous diffusion. All prepared solid dispersions showed dissolution improvement compared to pure drug, with Gelucire 50/13 as the superior carrier over Gelucire 44/14. Almost similar dissolution profile was obtained as a function of storage time; this can be explained by no change in XRD and DSC pattern after 45 days storage period.

Expansion of human mesenchymal stem cells using the wave bioreactor system with pulsed electromagnetic field stimulation for enhanced cell culture performance

( Sayan Deb Dutta ),( Keya Ganguly ),( Dinesh Patel ),( Tejal Patel ),( Ki-taek Lim ) 한국농업기계학회 2021 한국농업기계학회 학술발표논문집 Vol.26 No.2

Most bone tissue-engineering models fail to demonstrate the complex cellular functions of living bone; therefore, most translational studies on bone tissue are performed in live models. To reduce the need for live models, we developed a stimulated micro-chip model for monitoring protein secretion during osteogenesis using human mesenchymal stem cells (hBMSCs). We established a bone micro-chip system for monitoring the in vitro differentiation and sensing the secreted proteins of hMSCs under a sinusoidal electromagnetic field (SEMF), which ameliorates bone healing in a biomimetic natural bone matrix. A 3V-1Hz SEMF biophysically stimulated osteogenesis by activating ERK-1/2 and promote phosphorylation of p38 MAPK kinases. Exposure to a 3V-1Hz SEMF upregulated the expression of osteogenesis-related genes, and enhanced the expression of key osteoregulatory proteins. We identified 23 proteins that were differentially expressed in stimulated hBMSC secretomes, or were absent in the control groups. Our on-chip stimulation technology is easy to use, versatile, and non-disruptive, and should have diverse applications in regenerative medicine and cell-based therapies.

Expansion of human mesenchymal stem cells through wave motion bioreactor system with pulsed electromagnetic field stimulation for enhanced cell culture and real-time glucose monitoring

( Sayan Deb Dutta ),( Keya Ganguly ),( Tejal Patel ),( Ki-taek Lim ) 한국농업기계학회 2021 한국농업기계학회 학술발표논문집 Vol.26 No.2

Mesenchymal stem cells (hMSCs) are considered as one of the promising approaches for treating several diseases in cell-based therapeutics. The current strategies for hMSCs expansion include the in vitro static culture system yielding a low number of cells. Therefore, a scalable, dynamic bioreactor-based culture system is needed to produce an adequate number of cells for clinical applications. In this study, a new strategy for hMSCs expansion is employed with a modified wave-motion bioreactor system coupled with continuous electromagnetic field (EMF) stimulation. For this purpose, hMSCs were tested in various EMF exposure (1V, 5V, and 10V-1Hz) to find the maximum viability for cell expansion. Interestingly, the hMSCs tend to form aggregate-like structures during the wave motion culture. We show that a 10V-1Hz EMF exposure (magnetic field: 5.82 G) during wave motion culture (35 rpm) induces the viability of hMSCs up to 15% than static culture as evaluated by WST-8 assay. Moreover, the long-term cell culture of hMSCs in wave bioreactor significantly enhanced the expression of osteogenic transcription factors, such as Runx2 (6.8-8.0 fold), ALP (8.0 fold), BSP (5-6.0 fold), and OCN (8-10.0 fold) compared to the static culture (28% higher as of control). We also found that the average glucose consumption was significantly higher compared to static culture as predicted by Six biosensor B.LV5. In the initial phase of cell culture, the average detectable level of glucose was 8.35±0.34 mM/μL and lactate was 0.63±0.05 mM/μL. However, after 7 days of dynamic culture, the available glucose in the media was estimated about 2.57±0.32 mM/μL and lactate was 7.67±0.26 mM/μL which was significantly higher than the static control group. The RNA-sequencing results further indicate the upregulation of major osteogenic/mechanically stimulated signaling pathways during wave motion culture of hMSCs. These results suggested that the use of 10V-1Hz (5.82 G) EMF is non-toxic for hMSCs, and the modification of wave bioreactor with externally controlled EMF has good potential for hMSCs proliferation and expansion.

Electromagnetic field-assisted cell-laden 3D printed poloxamer-407 hydrogel for enhanced osteogenesis

( Sayan Deb Dutta ),( Keya Ganguly ),( Tejal Patel ),( Ki-taek Lim ) 한국농업기계학회 2021 한국농업기계학회 학술발표논문집 Vol.26 No.2

3D bioprinted hydrogel has gained enormous attention, especially in tissue engineering, owing to its attractive structure and excellent biocompatibility. In this study, we demonstrated that 3D bioprinted cell-laden ‘thermoresponsive’ poloxamer-407 (P407) gels have the potential to stimulate osteogenic differentiation of apical papilla stem cells (SCAPs) under the influence of low voltage- frequency 1V-1Hz (0.14 mT), 5V-1Hz (0.62 mT), and 10V-1Hz (1.21 mT) electromagnetic fields (EMFs). Their exposure time was 5 min/day, 10 min/day, 20 min/day, and 30 min/day for each hydrogel group, respectively. The developed hydrogel exhibited higher mechanical strength as well as good printability, showing high-quality micro-architecture. Moreover, the as-printed hydrogels (5 mm × 5 mm) were loaded with plasminogen activator inhibitor-1 (PAI-1) for testing the combined effect of PAI-1 and EMFs on SCAP differentiation. Interestingly, the 3D hydrogels showed improved viability and differentiation of SCAPs under EMFs' influence as examined by live/dead assay and alizarin Red-S staining, respectively. Our results demonstrated that DSPP and DMP-1 markers' expression significantly increased (3.8-fold) in 5V (0.62 mT) EMFs treatment. A similar fashion was also observed in ALP and Col-1(2.80-fold), comparable to the control groups. Therefore, the higher expression of theses gene markers (DSPP, DMP-1 ALP, and Col-1) indicated their better osteogenic efficiency of P407-encapsulated SCAPs in the presence of EMFs. The results confirmed that P407 hydrogels are non-toxic for encapsulation of SCAPs, yielding high cell viability and accelerate the cell migration potential. The 3D hydrogels with PAI-1 exhibited high mRNA expression levels for osteogenic/odontogenic gene markers (ALP, Col-1, DSPP, and DMP-1) vis-à-vis control after 14 days of in vitro culture. Our findings suggest that 3D bioprinted P407 hydrogels are biocompatible for SCAP encapsulation, and the applied low voltage-frequency EMFs could effectively improve dental tissue regeneration, particularly for oral applications.

3D printing of a conductive polypyrrole-grafted gelatin methacrylate (GelMA)-based hydrogels for continuous microcurrent stimulation of human mesenchymal stem cells

( Sayan Deb Dutta ),( Keya Ganguly ),( Tejal Patel ),( Ki-taek Lim ) 한국농업기계학회 2021 한국농업기계학회 학술발표논문집 Vol.26 No.2

Electrical stimulation has been shown to ameliorate bone healing for a long time. This study developed a hybrid and 3D printable conductive methacrylated gelatin-polypyrrole (GelMA-PPy)-based photocurable and self-healing hydrogel inks for continuous microcurrent stimulation. For this, a custom-made electrical stimulation device (DC stimulation) was used to evaluate the osteogenic differentiation of human bone mesenchymal stem cells (hMSCs). The pyrrole was chemically grafted onto the surface of GelMA via a one-step conjugation reaction with ammonium persulfate (APS) and cross-linked with iron (III) chloride. The fabricated hydrogel was characterized by proton nuclear magnetic resonance (1H-NMR), scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR) to analyze the grafting and chemical interaction. The as-prepared hydrogel exhibited higher mechanical and swelling properties compared to pure GelMA scaffolds. The 3D printed GelMA-PPy hydrogel showed improved cell viability (~12.6%) when exposed to 500 mV/day current, compared to pure GelMA after 7 and 14 days of cell culture. Interestingly,16.0~20.0-fold higher expression of osteogenic genes and protein markers (Runx2, ALP, OCN, and OPN) were observed in the GelMA-PPy treated groups than control suggest that pyrrole incorporation into GelMA matrix significantly improved the conductivity and osteogenic differentiation of hMSCs. Therefore, this study shows that the hMSCs react differentially to low-voltage DC electrical stimulation in the presence of GelMA-PPy scaffolds, which could be used as an ideal material for electrical stimulation for tissue engineering.

Pulsatile pressure mechanical stimulation on 3D printed gelatin methacrylate (GelMA)/ cellulose nanocrystals hybrid hydrogel promotes osteogenic differentiation of human mesenchymal stem cells

( Keya Ganguly ),( Sayan Deb Dutta ),( Dinesh Patel ),( Tejal Patel ),( Ki-taek Lim ) 한국농업기계학회 2021 한국농업기계학회 학술발표논문집 Vol.26 No.2

The rapid infiltration and osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBMSCs) on 3D printed osteogenic scaffolds represents a promising strategy to promote bone remodeling. However, the effect of constant wear and tear resulting from physical activities on mechanical integrity and functionality of tissue engineering constructs is crucial to determine before scaffold implantation. Therefore, we have focused on constructing an indigenous pulsatile bioreactor system creating artificial pressure loading microenvironment on GelMA/cellulose nanocrystals 3D-printed hydrogel to analyze the osteogenic differentiation of hBMSCs under a constant pulsatile pressure stimulation. The osteogenic differentiation potential of the hBMSCs seeded onto the fabricated scaffold was monitored after 7 and 14 days of cell culture under a pulsatile regiment of 10 ± 0.8 kPa pressure stimulation. Concurrently, hBMSCs maintained under static condition was taken as the control set. Our results indicated a 14.8% increase in the hBMSCs viability analyzed through the WST-8 assay and Live-Dead assay. Besides, increased adherence efficiency was evident by the morphometric analysis of the actin cytoskeletal arrangements and the expression of focal adhesion protein (Paxillin) determined by the immunocytochemistry analysis. Moreover, the qRT-PCR results after 7 days of cell culture indicated a higher expression of the early osteogenic marker genes, including ALP (7-fold), Runx2 (10.0-fold), OSX (5.8-fold), and mechanosensitive marker genes YAP/TAZ (4.2-fold), confirming the massive onset of early osteogenic differentiation in the hBMSCs. Similarly, the expression of the late osteogenic marker genes, including COL1 (8.0-fold), OPN (15.0-fold), and BSP (12.0-fold), was noted to be higher in cells cultured under pressure stimulation after 14 days of cell culture. Besides, the transcriptome analysis revealed the regulation of mechanosensitive genes during pressure stimulation than static group. The pulsatile pressure mechanical stimulation can be used to predetermine the mechanical potential of bone constructs and rapid osteogenic differentiation of hBMSCs.

Fluid shear stress-induced osteogenic differentiation of human mesenchymal stem cells on a 3D printed nanohydroxyapatite-GelMA hydrogel by a custom-designed six well perfusion chamber system

( Keya Ganguly ),( Sayan Deb Dutta ),( Tejal Patel ),( Ki-taek Lim ) 한국농업기계학회 2021 한국농업기계학회 학술발표논문집 Vol.26 No.2

Bone tissue engineering has emerged as an excellent alternative to the traditional treatment strategies of bone injuries. However, current in-vitro systems do not fully mimic the biological environment of the bone defects. Hence, the design of bioreactor system is worth investing to allow monitoring of the de-novo bone formation in vitro. Herein, we have evaluated the osteogenic differentiation of human bone marrow derived mesenchymal stem cells seeded on to 3D printed nanohydroxyapatite-GelMA (nHAp-GelMA) hydrogel under the different flow rates (0.1 mL/ min, 0.25 mL/ min, and 0.5 mL/ min) in a custom designed perfusion type bioreactor. The mechanical property of the as-fabricated hydrogel increased as the concentration of hydroxyapatite increased from 0.5 to 2%, respectively. Moreover, the incorporation of nHAp into GelMA matrix also improved the swelling efficiency and mineralization potential in vitro. Our results indicated a higher osteogenic differentiation in the hBMSCs under the fluid shear stress as compared to the static cultures. A 10~15% increase in the cell viability was observed under the varying fluid shear stress as determined by the WST-8 assay and the Live-Dead cell viability assay. Moreover, an enhancement in the overall osteogenic differentiation markers in the hBMSCs under the fluid shear stress (as of control) was evident by the qRT-PCR analysis of the osteogenic marker genes including ALP (7.0~9.5-fold), Runx2 (16.5-fold), OSX (6.5-fold), Col1 (18.0-fold), OPN (10.8-fold), and BSP (12.5-fold). The upregulation of the respective proteins was also supported by the transcriptome analysis. Also, applied shear stress induced the secretion of several growth factors and cytokines. Taken together, our study indicated fluid-shear stress by the custom-designed perfusion chamber induces hBMSC differentiation and in vitro bone regeneration.