Centre for Nanosciences
Amrita Institute of Medical Sciences,
Amrita Vishwa Vidyapeetham
AIMS Ponekkara P. O., Kochi, Kerala - 682 041, India.

0484 285 8750
researchsecretary@aims.amrita.edu
 

 

Ph. D. in Bioengineering (2013) from Amrita Vishwa Vidyapeetham. Experience as Research Assistant at the Institute of Biomedical Sciences, Taiwan, Taipei, as Visiting Scholar at Mikos Lab, Department of Bioengineering, Rice University, USA, as post-doctoral fellow at ACNSMM, Amrita Vishwa Vidyapeetham, and as Postdoctoral Fellow at the Centre for Bioengineering, Trinity College, Dublin, Ireland. Joined Amrita in 2017, as faculty, to pursue research in the area of bioengineering and regenerative medicine. Has over 20 peer-reviewed research publications and two book chapters to his credit. Research interest is in understanding the fundamentals of immunomodulatory and regenerative properties in adult stem cells and bioengineered matrices, for functional tissue regeneration, and is also focussed on the translational aspects of stem cell products and cell-derived matrices for regenerative medicine.

Publications

Publication Type: Journal Article

Year of Publication Title

2019

D. Olvera, Schipani, R., Binulal Nelson Sathy, and Kelly, D. J., “Electrospinning of Highly Porous yet Mechanically Functional Microfibrillar Scaffolds at the Human Scale for Ligament and Tendon Tissue Engineering”, Biomedical Materials , vol. 14, no. 3, p. 035016, 2019.[Abstract]


Electrospun fibers offer tremendous potential for tendon and ligament tissue engineering, yet developing porous scaffolds mimicking the size, stiffness and strength of human tissues remains a challenge. Previous studies have rolled, braided, or stacked electrospun sheets to produce three-dimensional (3D) scaffolds with tailored sizes and mechanical properties. A common limitation with such approaches is the development of low porosity scaffolds that impede cellular infiltration into the body of the implant, thereby limiting their regenerative potential. Here, we demonstrate how varying the rotational speed of the collecting mandrel during the electrospinning of poly(ε-caprolactone) (PCL) can be used to limit inter-fiber fusion (or fiber welding). Increasing the fraction of unfused fibers reduced the flexural rigidity of the electrospun sheets, which in turn allowed us to bundle the fibers into 3D scaffolds with similar dimensions to the human anterior cruciate ligament (ACL). These unfused fibers allowed for higher levels of porosity (up to 95%) that facilitated the rapid migration of mesenchymal stem cells (MSCs) into the body of the scaffolds. Mechanical testing demonstrated that the fiber-bundles possessed a Young's modulus approaching that of the native human ACL. The scaffolds were also capable of supporting the differentiation of MSCs towards either the fibrocartilage or ligament/tendon lineage. This novel electrospinning strategy could be used to produce mechanically functional, yet porous, scaffolds for a wide range of biomedical applications.

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2019

Binulal Nelson Sathy, Daly, A., Gonzalez-Fernandez, T., Olvera, D., Cunniffe, G., McCarthy, H. O., Dunne, N., Jeon, O., Alsberg, E., Donahue, T. L. Haut, and Kelly, D. J., “Hypoxia Mimicking Hydrogels to Regulate the Fate of Transplanted Stem Cells”, Acta Biomater, vol. 88, pp. 314-324, 2019.[Abstract]


Controlling the phenotype of transplanted stem cells is integral to ensuring their therapeutic efficacy. Hypoxia is a known regulator of stem cell fate, the effects of which can be mimicked using hypoxia-inducible factor (HIF) prolyl hydroxylase inhibitors such as dimethyloxalylglycine (DMOG). By releasing DMOG from mesenchymal stem cell (MSC) laden alginate hydrogels, it is possible to stabilize HIF-1α and enhance its nuclear localization. This correlated with enhanced chondrogenesis and a reduction in the expression of markers associated with chondrocyte hypertrophy, as well as increased SMAD 2/3 nuclear localization in the encapsulated MSCs. In vivo, DMOG delivery significantly reduced mineralisation of the proteoglycan-rich cartilaginous tissue generated by MSCs within alginate hydrogels loaded with TGF-β3 and BMP-2. Together these findings point to the potential of hypoxia mimicking hydrogels to control the fate of stem cells following their implantation into the body. STATEMENT OF SIGNIFICANCE: There are relatively few examples where in vivo delivery of adult stem cells has demonstrated a true therapeutic benefit. This may be attributed, at least in part, to a failure to control the fate of transplanted stem cells in vivo. In this paper we describe the development of hydrogels that mimic the effects of hypoxia on encapsulated stem cells. In vitro, these hydrogels enhance chondrogenesis of MSCs and suppress markers associated with chondrocyte hypertrophy. In an in vivo environment that otherwise supports progression along an endochondral pathway, we show that these hydrogels will instead direct mesenchymal stem cells (MSCs) to produce a more stable, cartilage-like tissue. In addition, we explore potential molecular mechanisms responsible for these phenotypic changes in MSCs.

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2018

Binulal Nelson Sathy, Daly, A. C., and Kelly, D. J., “Engineering Large Cartilage Tissues using Dynamic Bioreactor Culture at Defined Oxygen Conditions”, Journal of Tissue Engineering , vol. 9, 2018.

2017

G. M. Cunniffe, Gonzalez-Fernandez, T., Daly, A., Binulal Nelson Sathy, Jeon, O., Alsberg, E., and Kelly, D. J., “ Three-Dimensional Bioprinting of Polycaprolactone Reinforced Gene Activated Bioinks for Bone Tissue Engineering.”, Tissue Eng Part A, vol. 23, no. 17-18, pp. 891-900, 2017.[Abstract]


<p>Regeneration of complex bone defects remains a significant clinical challenge. Multi-tool biofabrication has permitted the combination of various biomaterials to create multifaceted composites with tailorable mechanical properties and spatially controlled biological function. In this study we sought to use bioprinting to engineer nonviral gene activated constructs reinforced by polymeric micro-filaments. A gene activated bioink was developed using RGD-γ-irradiated alginate and nano-hydroxyapatite (nHA) complexed to plasmid DNA (pDNA). This ink was combined with bone marrow-derived mesenchymal stem cells (MSCs) and then co-printed with a polycaprolactone supporting mesh to provide mechanical stability to the construct. Reporter genes were first used to demonstrate successful cell transfection using this system, with sustained expression of the transgene detected over 14 days postbioprinting. Delivery of a combination of therapeutic genes encoding for bone morphogenic protein and transforming growth factor promoted robust osteogenesis of encapsulated MSCs in vitro, with enhanced levels of matrix deposition and mineralization observed following the incorporation of therapeutic pDNA. Gene activated MSC-laden constructs were then implanted subcutaneously, directly postfabrication, and were found to support superior levels of vascularization and mineralization compared to cell-free controls. These results validate the use of a gene activated bioink to impart biological functionality to three-dimensional bioprinted constructs.</p>

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2017

S. Pentlavalli, Chambers, P., Binulal Nelson Sathy, O'Doherty, M., Chalanqui, M., Kelly, D. J., Haut-Donahue, T., McCarthy, H. O., and Dunne, N. J., “Simple Radical Polymerization of Poly(Alginate-Graft-N-Isopropylacrylamide) Injectable Thermoresponsive Hydrogel with the Potential for Localized and Sustained Delivery of Stem Cells and Bioactive Molecules.”, Macromol Biosci, vol. 17, no. 11, 2017.[Abstract]


<p>In this study, thermoresponsive copolymers that are fully injectable, biocompatible, and biodegradable and are synthesized via graft copolymerization of poly(N-isopropylacrylamide) onto alginate using a free-radical reaction are presented. This new synthesis method does not involve multisteps or associated toxicity issues, and has the potential to reduce scale-up difficulties. Chemical and physical analyses verify the resultant graft copolymer structure. The lower critical solution temperature, which is a characteristic of sol-gel transition, is observed at 32 °C. The degradation properties indicate suitable degradation kinetics for drug delivery and bone tissue engineering applications. The synthesized P(Alg-g-NIPAAm) hydrogel is noncytotoxic with both human osteosarcoma (MG63) cells and porcine bone marrow derived mesenchymal stem cells (pBMSCs). pBMSCs encapsulated in the P(Alg-g-NIPAAm) hydrogel remain viable, show uniform distribution within the injected hydrogel, and undergo osteogenic and chondrogenic differentiation under appropriate culture conditions. Furthermore, for the first time, this work will explore the influence of alginate viscosity on the viscoelastic properties of the resulting copolymer hydrogels, which influences the rate of medical device formation and subsequent drug release. Together the results of this study indicate that the newly synthesized P(Alg-g-NIPAAm) hydrogel has potential to serve as a versatile and improved injectable platform for drug delivery and bone tissue engineering applications.</p>

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2017

T. Gonzalez-Fernandez, Binulal Nelson Sathy, Hobbs, C., Cunniffe, G. M., McCarthy, H. O., Dunne, N. J., Nicolosi, V., O'Brien, F. J., and Kelly, D. J., “Mesenchymal Stem Cell Fate Following Non-viral Gene Transfection Strongly Depends on the Choice of Delivery Vector”, Acta Biomaterialia, vol. 55, pp. 226-238, 2017.[Abstract]


Controlling the phenotype of mesenchymal stem cells (MSCs) through the delivery of regulatory genes is a promising strategy in tissue engineering (TE). Essential to effective gene delivery is the choice of gene carrier. Non-viral delivery vectors have been extensively used in TE, however their intrinsic effects on MSC differentiation remain poorly understood. The objective of this study was to investigate the influence of three different classes of non-viral gene delivery vectors: (1) cationic polymers (polyethylenimine, PEI), (2) inorganic nanoparticles (nanohydroxyapatite, nHA) and (3) amphipathic peptides (RALA peptide) on modulating stem cell fate after reporter and therapeutic gene delivery. Despite facilitating similar reporter gene transfection efficiencies, these nanoparticle-based vectors had dramatically different effects on MSC viability, cytoskeletal morphology and differentiation. After reporter gene delivery (pGFP or pLUC), the nHA and RALA vectors supported an elongated MSC morphology, actin stress fibre formation and the development of mature focal adhesions, while cells appeared rounded and less tense following PEI transfection. These changes in MSC morphology correlated with enhanced osteogenesis following nHA and RALA transfection and adipogenesis following PEI transfection. When therapeutic genes encoding for transforming growth factor beta 3 (TGF-β3) and/or bone morphogenic protein 2 (BMP2) were delivered to MSCs, nHA promoted osteogenesis in 2D culture and the development of an endochondral phenotype in 3D culture, while RALA was less osteogenic and appeared to promote a more stable hyaline cartilage-like phenotype. In contrast, PEI failed to induce robust osteogenesis or chondrogenesis of MSCs, despite effective therapeutic protein production. Taken together, these results demonstrate that the differentiation of MSCs through the application of non-viral gene delivery strategies depends not only on the gene delivered, but also on the gene carrier itself. Statement of Significance Nanoparticle-based non-viral gene delivery vectors have been extensively used in regenerative medicine, however their intrinsic effects on mesenchymal stem cell (MSC) differentiation remain poorly understood. This paper demonstrates that different classes of commonly used non-viral vectors are not inert and they have a strong effect on cell morphology, stress fiber formation and gene transcription in MSCs, which in turn modulates their capacity to differentiate towards osteogenic, adipogenic and chondrogenic lineages. These results also point to the need for careful and tissue-specific selection of nanoparticle-based delivery vectors to prevent undesired phenotypic changes and off-target effects when delivering therapeutic genes to damaged or diseased tissues. © 2017 Acta Materialia Inc.

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2015

Binulal Nelson Sathy, Watson, B. M., Kinard, L. A., Spicer, P. P., Dahlin, R. L., Mikos, A. G., and Shantikumar V Nair, “Bone Tissue Engineering with Multilayered Scaffolds—Part II: Combining Vascularization with Bone Formation in Critical-Sized Bone Defect”, Tissue Engineering Part A, vol. 21, pp. 2495-2503, 2015.[Abstract]


Our previous in vivo study showed that multilayered scaffolds made of an angiogenic layer embedded between an osteogenic layer and an osteoconductive layer, with layer thickness in the 100–400 μm range, resulted in through-the-thickness vascularization of the construct even in the absence of exogenous endothelial cells. The angiogenic layer was a collagen–fibronectin gel, and the osteogenic layer was made from nanofibrous polycaprolactone while the osteoconductive layer was made either from microporous hydroxyapatite or microfibrous polycaprolactone. In this follow-up study, we implanted these acellular and cellular multilayered constructs in critical-sized rat calvarial defects and evaluated their vascularization and bone formation potential. Vascularization and bone formation at the defect were evaluated and quantified using microcomputed tomography (microCT) followed by perfusion of the animals with the radio opaque contrast agent, MICROFIL. The extent of bony bridging and union within the critical-sized defect was evaluated using a previously established scoring system from the microCT data set. Similarly the new bone formation in the defect was quantified from the microCT data set as previously reported. Histological evaluation at 4 and 12 weeks validated the microCT findings. Our experimental results showed that acellular multilayered scaffolds with microscale-thick nanofibers and porous ceramic discs with angiogenic zone at their interface can regenerate functional vasculature and bone similar to that of cellular constructs in critical-sized calvarial defects. This result suggests that suitably bioengineered acellular multilayered constructs can be an improved and more translational approach in functional in vivo bone regeneration.

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2015

Binulal Nelson Sathy, Dr. Ullas Mony, Dr. Deepthy Menon, VK, B., AG, M., and Shantikumar V Nair, “Bone Tissue Engineering with Multilayered Scaffolds-Part I: An Approach for Vascularizing Engineered Constructs In Vivo.”, Tissue Eng Part A., pp. 19-20, 2015.[Abstract]


Obtaining functional capillaries through the bulk has been identified as a major challenge in tissue engineering, particularly for critical-sized defects. In the present study, a multilayered scaffold system was developed for bone tissue regeneration, designed for through-the-thickness vascularization of the construct. The basic principle of this approach was to alternately layer mesenchymal stem cell-seeded nanofibers (osteogenic layer) with microfibers or porous ceramics (osteoconductive layer), with an intercalating angiogenic zone between the two and with each individual layer in the microscale dimension (100-400 μm). Such a design can create a scaffold system potentially capable of spatially distributed vascularization in the overall bulk tissue. In the cellular approach, the angiogenic zone consisted of collagen/fibronectin gel with endothelial cells and pericytes, while in the acellular approach, cells were omitted from the zone without altering the gel composition. The cells incorporated into the construct were analyzed for viability, distribution, and organization of cells on the layers and vessel development in vitro. Furthermore, the layered constructs were implanted in the subcutaneous space of nude mice and the processes of vascularization and bone tissue regeneration were followed by histological and energy-dispersive X-ray spectroscopy (EDS) analysis. The results indicated that the microenvironment in the angiogenic zone, microscale size of the layers, and the continuously channeled architecture at the interface were adequate for infiltrating host vessels through the bulk and vascularizing the construct. Through-the-thickness vascularization and mineralization were accomplished in the construct, suggesting that a suitably bioengineered layered construct may be a useful design for regeneration of large bone defects.

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Dr. Binulal Nelson Sathy
Asst. Professor, Nanosciences, Center for Nanosciences, Kochi

binulalns@aims.amrita.edu