Biology subjects

Mohanty, R. P.

Publications and source records attributed to Mohanty, R. P..

4 recordsLinked to original sources

bioRxiv2025

Magnetized Cellbots to Spatiotemporally Control Differentiation of Human-Induced Pluripotent Stem Cells

Precise spatiotemporal control of gene expression and cellular differentiation is essential for engineering native-like multicellular structures. Current cell differentiation approaches typically rely on externally provided inputs whose effects are not targeted to distinct cells in the appropriate state and hence cannot spatially organize and mature tissue structures as needed. Our work introduces a magnetically controlled microrobot (MR) platform for guiding mammalian cells to desired locations that, combined with synthetic biology, delivers biological signals at precise locations and times, enabling spatiotemporal control of cell-fate decision-making. We use synNotch, a cell-cell contact-based biological signaling that induces relevant gene expression in receivers when the receiver cells contact sender cells through ligand-receptor binding. Magnetically driven MRs are then allowed to be internalized by sender cells, resulting in magnetized sender cellbots. Using a 3-pair orthogonal Helmholtz coil system, we guided magnetized sender cellbots to precise locations in a receiver cell culture, activating desired fluorescent protein expression in target Chinese Hamster Ovary (CHO) receiver cells. Next, we engineered Human-Induced Pluripotent Stem Cells (hiPSC) to function as receivers that can be instructed by senders to differentiate into endothelial cells (ECs) via overexpression of ETV2 (ETS variant transcription factor 2), a master transcriptional regulator of endothelial cell development. Using our magnetic platform, we guided multiple sender cellbots to target locations on a monolayer of hiPSC receivers, resulting in differentiation of receivers into ECs and possible onset of vascular formation. Our approach provides a foundation for the engineering spatial patterns by activating conditional triggers based on MR location and cell state at multiple time points, enabling several applications such as control of organoid architecture.

synthetic biology↗

bioRxiv2023

Bio-contaminated Plastic Micropipette Tip Sterilization Stations: Environmentally, Ecologically, and Energetically Viable Solution

Bioscientific research laboratories significantly contribute to global plastic waste production through their widespread use of plastic products, such as single-use micropipette tips. However, biologically contaminated pipette tips must undergo several washing and sterilization steps before being reused or recycled. Grenova Solutions provides such a decontamination station called TipNovus, which has been implemented by academic and government research labs to reuse pipette tips in sensitive biological assays. Despite this success, the high initial purchasing cost of these washing stations deter many laboratories from incorporating it into their workflow. Additionally, researchers are reluctant to reuse pipette tips due to concerns that the washing process may not thoroughly remove all contaminants. To mitigate these concerns, considering the University of Texas at Austin as an example, we performed a cost-benefit analysis of employing a university-wide washing station. We estimated that only single-time reuse of the pipette tips could result in a 100% return on investment from the equipment purchase cost within 3 months. Then, with our pilot experiments, we confirmed the TipNovus washing steps to be 100% efficient in sterilizing pipette tips contaminated with T7 bacteriophage, enabling their reuse in bacteriophage functionality assays. Finally, we proposed an alternative and more convenient autoclave-based sterilization method to decontaminate pipette tips. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=77 SRC="FIGDIR/small/572721v2_ufig1.gif" ALT="Figure 1"> View larger version (33K): org.highwire.dtl.DTLVardef@120ddceorg.highwire.dtl.DTLVardef@c222d6org.highwire.dtl.DTLVardef@17d496forg.highwire.dtl.DTLVardef@60444f_HPS_FORMAT_FIGEXP M_FIG C_FIG SYNOPSISSingle-use plastic micropipette tips discarded by bioresearch labs generate substantial waste. This study reports adopting standardized tip-washing and reuse systems in labs greatly reduces plastic waste and research expenditures.

bioengineering↗

bioRxiv2023

Electrostatic-driven Interactions Enhance Intratumoral Retention and Antitumor Efficacy of Immune Checkpoint Blockade Antibodies

Tumor extracellular matrix (ECM) forms a net negative charged network that interacts with and hinders the transport of molecules partly based on electrostatic interactions. The focus on drug delivery in solid tumors has traditionally been on developing neutral charge coatings to minimize interactions with the ECM for improved transport. In contrast to this prior work, we recently found a cationic peptide that interacted electrostatically with the negatively charged components of the ECM, resulting in enhanced uptake and retention of nanoparticles in tumor ECM and tumor tissue. Based on this previous study, here, we hypothesize that the electrostatically driven interactions of the cationic peptide will improve the binding and retention of immune checkpoint blockade antibodies (ICBs), ultimately enhancing their antitumor immunogenic responses. We prepared peptide antibody (Ab) conjugates by conjugating the cationic peptide to ICBs, anti-cytotoxic T lymphocyte antigen 4 ({propto}-CTLA4) and anti-programmed cell death ligand-1 ({propto}-PD-L1) Abs, using copper-free click chemistry. We confirmed an average of 1 - 2 peptides per Ab. The cationic peptide electrostatically interacted with the net negatively charged tumor ECM and improved the binding of the Abs to the tumor ECM without affecting their antigen recognition capacities. Modifying the Abs due to cationic peptide conjugation reduced the systemic exposure of the Abs and did not induce treatment-related toxicities. We quantified a significantly higher population of tumor-infiltrating CD8+ T cells and a significant depletion of regulatory T cells in the tumor and tumor-draining lymph nodes upon peptide conjugation, which resulted in a better therapeutic outcome of the ICBs. ONE SENTENCE SUMMARYElectrostatic interaction-based intratumoral retention enhances antitumor responses of immune checkpoint blockade antibodies upon local administration.

bioengineering↗

bioRxiv2023

Discovery of peptides for targeted delivery of mRNA lipid nanoparticles to cystic fibrosis lung epithelia

For cystic fibrosis (CF) patients, a lung targeted gene therapy would significantly alleviate pulmonary complications associated with morbidity and mortality. However, mucus in the airways and cell entry pose huge delivery barriers for local gene therapy. Here, we used phage display technology to select for and identify mucus- and cell-penetrating peptides against primary human bronchial epithelial cells (pHBECs) from CF patients cultured at air-liquid interface (ALI). At ALI, pHBECs produce mucus and reflect CF disease pathology, making it a clinically relevant model. Using this model, we discovered a lead candidate peptide, and incorporated it into lipid nanoparticles (LNPs) to deliver mRNA to pHBECs and mouse lungs in vivo. Compared to LNPs without our peptide, peptide-LNPs demonstrated 7.8-fold and 4.8-fold higher mRNA expression in vitro and in vivo, respectively. Since gene delivery to pHBECs is a significant challenge, we are encouraged by these results and anticipate that our peptide could be used to successfully deliver CF gene therapies in future work.

bioengineering↗