Biology subjects

Mogha, P.

Publications and source records attributed to Mogha, P..

4 recordsLinked to original sources

bioRxiv2026

Shape, Shrink, Spheroid: A DIY High-throughput Spheroid Generation Device

3D spheroids, which closely replicate three-dimensional cell-cell and cell-extracellular matrix interactions, offer superior predictive capabilities compared to conventional 2D monolayer cultures, positioning them as forward-looking platforms in drug testing, cancer biology, and regenerative medicine. However, high-throughput generation of uniform sized spheroids is still a technological challenge. In one hand, the use of conventional ultra-low attachment (ULA) multiwell plates for this purpose is labour intensive and complex. On the other hand, the use of microfabricated facilities demands cutting-edge infrastructure such as clean room, photolithography, and microfluidic setup which are often unavailable for the resource constrained laboratories. In this study, we addressed these problems by developing a low-cost Do-It-Yourself (DIY), polydimethylsiloxane (PDMS) and agarose-based spheroid generation device, capable of producing and maintaining hundreds of spheroids with minimal user intervention. We have demonstrated two variants based on their size, termed here as S1 and S2 devices which fit into 6-well and 12-well plates, and can generate 600 and 1200 uniform-sized spheroids respectively. We validated our device with various cell lines including primary and cancerous cell lines. We further demonstrated the drug testing capabilities of the device by estimating the IC50 value of the anticancer drug Temozolomide on U87-MG. The value was comparable with the same obtained from the spheroids generated using conventional ULA plates. Additional attachment of a perfusion system made the device suitable for long-term spheroid culture without much user intervention. Furthermore, the devices can also be used for the production of spheroids with gradually changing diameters in a controlled manner, resembling a size gradient. This feature is useful for checking the effect of drugs on different-sized spheroids and for co-culturing spheroids with varying cell densities, mimicking the disease architecture. We have co-cultured two types of the placental trophoblast cells, i.e., extravillous trophoblast (HTR-8) and syncytiotrophoblast (BeWo) with varying densities. In summary, this paper demonstrates a unique DIY method for a high-throughput uniform-sized spheroid generation at a fraction of cost which can be deployed to resource-constrained labs.

bioengineering↗

bioRxiv2021

Extracellular Matrix protein gelatin provides higher expansion, reduces size heterogeneity, and maintains cell stiffness in a long-term culture of mesenchymal stem cells.

Extracellular matrices (ECM) present in our tissues play a significant role in maintaining tissue homeostasis through various physical and chemical cues such as topology, stiffness, and secretion of biochemicals. They are known to influence the behaviour of resident stem cells. It is also known that ECM type and coating density on cell culture plates strongly influence in vitro cellular behaviour. However, the influence of ECM protein coating on long term mesenchymal stem cell expansion has not been studied yet. To address this gap, we cultured bone-marrow derived hMSCs for multiple passages on the tissue culture plastic plates coated with 25 g/ml of various ECM proteins. We found that cells on plates coated with ECM proteins had much higher proliferation compared to the regular tissue culture plates. Further, gelatin coated plates helped the cells to grow faster compared to collagen, fibronectin, and laminin coated plates. Additionally, the use of Gelatin showed less size heterogeneity among the cells when expanded from passages P3 to P9. Gelatin also helped in maintaining cellular stiffness which was not observed across other ECM proteins. In summary, in this research, we have shown that gelatin which is the least expensive compared to other ECM proteins provides a better platform for mesenchymal stem cell expansion.

cell biology↗

bioRxiv2018

Soft Substrate Maintains Proliferative and Multi-lineage Potential of Human Mesenchymal Stem Cells on Long Term Expansion

Human mesenchymal stem cells (hMSCs), when cultured on tissue culture plate (TCP) for in vitro expansion, they spontaneously lose their proliferative capacity and multi-lineage differentiation potential. They also lose their distinct spindle morphology and become large and flat. After a certain number of population doubling, they enter into permanent cell cycle arrest, called senescence. This is a major roadblock for clinical use of hMSCs which demands large number of cells. A cell culture system is needed which can maintain the stemness of hMSCs over long term passages yet simple to use. In this study, we explore the role of substrate rigidity in maintaining stemness. hMSCs were serially passaged on TCP and 5 kPa poly-acrylamide gel for 20 population doubling. It was found that while on TCP, cell growth reached a plateau at cumulative population doubling (CPD) = 12.5, on 5 kPa gel, they continue to proliferate linearly till we monitored (CPD = 20). We also found that while on TCP, late passage MSCs lost their adipogenic potential, the same was maintained on soft gel. Cell surface markers related to MSCs were also unaltered. We demonstrated that this maintenance of stemness was correlated with delay in onset of senescence, which was confirmed by {beta}-gal assay and by differential expression of vimentin, Lamin A and Lamin B. As preparation of poly-acrylamide gel is a simple, well established, and well standardized protocol, we believe that this system of cell expansion will be useful in therapeutic and research applications of hMSCs.\n\nOne Sentence SummaryhMSCs retain their stemness when expanded in vitro on soft polyacrylamide gel coated with collagen by delaying senescence.\n\nSignificance StatementFor clinical applications, mesenchymal stem cells (MSCs) are required in large numbers. As MSCs are available only in scarcity in vivo, to fulfill the need, extensive in vitro expansion is unavoidable. However, on expansion, they lose their replicative and multi-lineage differentiation potential and become senescent. A culture system that can maintain MSC stemness on long-term expansion, without compromising the stemness, is need of the hour. In this paper, we identified polyacrylamide (PAA) hydrogel of optimum stiffness that can be used to maintain stemness of MSCs during in vitro long term culture. Large quantity of MSCs thus grown can be used in regenerative medicine, cell therapy, and in treatment of inflammatory diseases.

bioengineering↗

bioRxiv2017

Soft drug-resistant ovarian cancer cells invade via two distinct mechanisms utilizing myosin IIB

The failure of chemotherapeutic drugs in treatment of various cancers is attributed to the acquisition of drug resistance. However, the invasion mechanisms of drug-resistant cancer cells remains incompletely understood. Here we address this question from a biophysical perspective by mapping the phenotypic alterations in ovarian cancer cells (OCCs) resistant to cisplatin and paclitaxel. We show that cisplatin-resistant (CisR), paclitaxel-resistant (PacR) and dual drug-resistant (i.e., resistant to both drugs) OCCs are softer and more contractile than drug-sensitive cells. Protease inhibition suppresses invasion of CisR cells but not of PacR and dual cells, suggesting protease-dependent mode of invasion in CisR cells and protease-independent mode in PacR and dual cells. Despite these differences, actomyosin contractility, mediated by the RhoA-ROCK2-Myosin IIB signaling pathway regulates both modes of invasion. Myosin IIB modulates matrix metalloproteinase-9 (MMP-9) secretion in CisR cells and nuclear squeezing in PacR and dual cells, thereby highlighting its importance as a potential therapeutic target for treatment of drug-resistant ovarian cancer cells.\n\nFinancial SupportAuthors acknowledge financial support from IIT Bombay Healthcare Initiative, CSIR andDepartment of Biotechnology (Govt. of India) (Grant # BT/PR14658/MED/31/107/2010).AK and BTwere supported by fellowships from UGC and CSIR respectively (Govt. of India).\n\nAuthors declare no competing financial interests\n\nAuthor contributions: AK, PR and SS designed the experiments. AK performed most of the experiments and analyzed the data.BT and SG developed drug resistant cell lines and did RT-PCR. MM performed western blot. AD performed AFM experiments. SD performed gelatin zymography. ABB, PM, AM and AD helped with live cell imaging experiments. AK and SS wrote the manuscript. All authors read and approved the final manuscript.\n\nSummary statement: This study identifies drug-specific differences in the modes of invasion utilized by ovarian cancer cells, and demonstrates the role of myosin IIB in regulating both modes of invasion.

biophysics↗