Enabling safer, more potent oligonucleotide therapeutics with bottlebrush polymer conjugates

PEG-ASO conjugates for efficient targeted delivery and migration inhibition in Cancer cell

Antisense oligonucleotides (ASO) specifically bind target RNAs resulted in gene silencing, thereby inhibiting cancer cell growth. Chemical modification based on polyethylene glycol (PEG) usually improve resistance to nuclease degradation. However, the specificity and cellular uptake of PEG-conjugated ASOs for tumor cells is still a challenge. In this work, the folate (FA) and maleimide co-modified PEG was prepared and bound with thiol-modified anti-miRNA-21 ASO to form the FA-PEG-ASO conjugates by thiol-maleimide Michael addition. During the FA-PEG-ASO preparation process, removing tris-(2-carboxyethyl) phosphine hydrochloride (TCEP) is the key for the high yields. Cell imaging results showed FA-PEG-ASO internalized by the cells taken up ∼5 times higher than the control HO-PEG-ASO prepared by maleimide modified PEG and anti-miRNA-21 ASO. In addition, FA-PEG-ASO exhibited higher target cleavage and a greater reduction in tumor cell migration ability. Together, FA-PEG-ASO is a promising therapeutic platform.

Accelerating Biologics PBPK Modelling with Automated Model Building: A Tutorial

Physiologically based pharmacokinetic (PBPK) modelling for biologics, such as monoclonal antibodies and therapeutic proteins, involves capturing complex processes, including target-mediated drug disposition (TMDD), FcRn-mediated recycling, and tissue-specific distribution. The Simcyp Designer Biologics PBPK Platform Model offers an intuitive and efficient platform for constructing mechanistic PBPK models with pre-defined templates and automated model assembly, reducing manual input and improving reproducibility. This tutorial provides a step-by-step guide to using the platform, highlighting features such as cross-species scaling, population variability simulations, and flexibility for model customization. Practical case studies demonstrate the platform's capability to streamline workflows, enabling rapid, mechanistic model development to address key questions in biologics drug development. By automating critical processes, this tool enhances decision-making in translational research, optimizing the modelling and simulation of large molecules across discovery and clinical stages.

PROTACs coupled with oligonucleotides to tackle the undruggable

Undruggable targets account for roughly 85% of human disease-related targets and represent a category of therapeutic targets that are difficult to tackle with traditional methods, but their considerable clinical importance. These targets are generally defined by planar functional interfaces and the absence of efficient ligand-binding pockets, making them unattainable for conventional pharmaceutical strategies. The advent of oligonucleotide-based proteolysis-targeting chimeras (PROTACs) has instilled renewed optimism in addressing these challenges. These PROTACs facilitate the targeted degradation of undruggable entities, including transcription factors (TFs) and RNA-binding proteins (RBPs), via proteasome-dependent mechanisms, thereby presenting novel therapeutic approaches for diseases linked to these targets. This review offers an in-depth examination of recent progress in the integration of PROTAC technology with oligonucleotides to target traditionally undruggable proteins, emphasizing the design principles and mechanisms of action of these innovative PROTACs.

Fabrication of lactoferrin-chitosan-etoposide nanoparticles with melatonin via carbodiimide coupling: In-vitro & in-vivo evaluation for colon cancer

This study presents the development of melatonin-coated lactoferrin-chitosan nanoparticles (ETP-CS-LF-MLT-NPs) using ionic gelation and carbodiimide coupling for colorectal cancer treatment. The nanoparticles were characterized by an average size of 208.7 ± 1.25 nm, a zeta potential of 30.77 ± 1.21 mV, and 82.45 % drug encapsulation efficiency. In vitro drug release studies showed sustained, pH-responsive release, with 98.68 ± 4.12 % released at pH 5.5 over 24 h. The nanoparticles exhibited significant cytotoxicity in HCT116 cells (IC50 = 15.32 μg/mL), inducing ROS generation, apoptosis, and G2/M cell cycle arrest, with notable downregulation of BCL2 gene expression. Enhanced cellular uptake due to lactoferrin targeting improved therapeutic efficacy. In In vivo studies, the nanoparticles demonstrated significant tumor reduction and selective colon accumulation in a DMH-induced colorectal cancer rat model, along with improved pharmacokinetics, showing extended plasma circulation and bioavailability compared to free etoposide. Biocompatibility assays, including hemolysis (<1 %), platelet aggregation, and HET-CAM tests, confirmed the safety profiling of the prepared nanoparticles. The nanoparticles also inhibited Proteus mirabilis (ZOI = 1.9 cm) and exhibited promising effects on the gut microbiome of treated animals. Altogether, ETP-CS-LF-MLT-NPs hold great potential for targeted colorectal cancer therapy, improving drug delivery, tumor targeting, bioavailability, and reducing systemic toxicity.

Reconfigurable Amphiphilic DNA Nanotweezer for Targeted Delivery of Therapeutic Oligonucleotides

Amphiphilic lipid oligonucleotide conjugates are powerful molecular-engineering materials that have been used for delivery of therapeutic oligonucleotides. However, conventional lipid oligonucleotide conjugates suffer from poor selectivity to target cells due to the nonspecific interaction between lipid tails and cell membranes. Herein, a reconfigurable DNA nanotweezer consisting of a c-Met aptamer and bischolesterol-modified antisense oligonucleotide was designed for c-Met-targeted delivery of therapeutic antisense oligonucleotides. The c-Met aptamer is used to keep the DNA nanotweezer in a "closed" state, which enables the hydrophobic interaction within bischolesterol moieties. As a result, the amphiphilic DNA nanotweezer shows only a weak interaction with the cell membrane. Upon the release of the c-Met aptamer, the DNA nanotweezer converts to an "open" state, which facilitates the insertion of a cholesterol moiety into the cell membrane. Thus, the reconfigurable DNA nanotweezer enables the selective membrane anchoring of the DNA nanotweezer in cancerous cells that highly expressed c-Met protein. Moreover, this amphiphilic DNA nanotweezer shows enhanced accumulation at the tumor site and the inhibition of tumor growth. Taking advantage of the stimuli-responsive membrane anchoring capability, this reconfigurable DNA nanotweezer could be further explored as a smart multifunctional platform for cancer therapy.

Bottlebrush Polymers with Sequence-Controlled Backbones for Enhanced Oligonucleotide Delivery

The clinical translation of oligonucleotide-based therapeutics continues to encounter challenges in delivery. In this study, we introduce a novel class of delivery vehicles for oligonucleotides that are based on poly(ethylene glycol) (PEG) bottlebrush polymers with sequence-defined backbones. Using solid-phase synthesis and bespoke phosphoramidites, the oligonucleotide and the polymer backbone can be assembled on the solid support. The synthesis allows chemical modifiers such as carbon 18 (C18) units to be incorporated into the backbone in specific patterns to modulate the cell-material interactions. Subsequently, PEG side chains were grafted onto the polymer segment of the resulting polymer-oligonucleotide conjugate, yielding bottlebrush polymers. We report an optimal pattern of the C18 modifier that leads to improved cellular uptake, plasma pharmacokinetics, biodistribution, and antisense activity in vivo. Our results provide valuable insights into the structure-property relationship of polymer-oligonucleotide conjugates and suggest the possibility of tuning the polymer backbone to meet the specific delivery requirements of various diseases.