A cocktail therapeutic strategy based on clofarabine-containing aptamer-PROTAC for enhanced cancer therapy

Palindrome-mediated DNA nanotubes with cell-specific aptamers to improve targeted antitumor effects and reduce toxicity on non-small cell lung cancer

Chemotherapy is regarded as a widely used and effective treatment strategy for lung cancer, although most conventional chemotherapeutics cause severe toxic side-effects due to their indiscriminate attacks on both cancerous and normal cells. Although nucleic acid nanomaterials are emerging as a promising drug delivery strategy, their clinical applications are limited by rapid degradation by nucleases and difficulties in targeting cancer cells. In this study, we have developed a Rhein-loaded aptamer-based DNA nanotube (DNT-S6@Rhein) for the targeted and efficient therapy of non-small cell lung cancer. Through the palindrome segments, two specified oligonucleotides were hybridized and folded into the well-defined nanotubes (DNT-S6), with the S6 aptamer distributed outside. The obtained nanotubes exhibited excellent serum stability and targeting ability towards A549 cells due to the firm structure and decoration of the S6 aptamer. Rhein, as an antitumor drug and DNA intercalator, can be effectively inserted into the DNT-S6. The drug-loaded nanotubes rapidly disassembled in intracellular environment and then the released Rhein was found to activate cellular apoptotic process and significantly suppress proliferation, migration and invasion of A549 cells. Moreover, DNT-S6@Rhein could efficiently accumulate in tumor regions, offering compelling therapeutic efficacy and biocompatibility under both in vitro and in vivo settings. These findings of this study provide a promising strategy for mitigating the inevitable systemic side-effects of chemotherapy and expand the potential application of DNA nanostructure on targeted drug delivery.

Advances in conjugate drug delivery System: Opportunities and challenges

Ideal drug delivery system is designed to accurately deliver the drug to its intended site. The development of conjugate drug delivery system introduces a novel pathway to precise drug delivery with advantages over traditional methods. The core of a conjugate drug delivery system comprises a molecule with two functional components, bounded by a linker structure. One component is responsible for delivering or stabilizing the conjugate, while the other is used to provide the therapeutic or diagnostic effects of the bioactivity. Conjugate drug delivery system improves patient health by maintaining the structural stability of drugs in molecular form, delivering therapeutics or diagnostic material to the target site, minimising off-target accumulation and promoting patient compliance. This system includes various types of drug conjugates that modulate drug pharmacokinetics, stability, absorption, and exposure in lesions and healthy tissues. In this review, we focus on the key characteristics and recent advances of various conjugate drug delivery systems and explore their mechanisms. We also point out the current challenges faced by conjugate drug delivery system and look forward to the future prospects.

A photoactivatable upconverting nanodevice boosts the lysosomal escape of PROTAC degraders for enhanced combination therapy

PROteolysis TArgeting Chimeras have received increasing attention due to their capability to induce potent degradation of various disease-related proteins. However, the effective and controlled cytosolic delivery of current small-molecule PROTACs remains a challenge, primarily due to their intrinsic shortcomings, including unfavorable solubility, poor cell permeability, and limited spatiotemporal precision. Here, we develop a near-infrared light-controlled PROTAC delivery device (abbreviated as USDPR) that allows the efficient photoactivation of PROTAC function to achieve enhanced protein degradation. The nanodevice is constructed by encapsulating the commercial BRD4-targeting PROTACs (dBET6) in the hollow cavity of mesoporous silica-coated upconversion nanoparticles, followed by coating a Rose Bengal (RB) photosensitizer conjugated poly-L-lysine (PLL-RB). This composition enables NIR light-activatable generation of cytotoxic reactive oxygen species due to the energy transfer from the UCNPs to PLL-RB, which boosts the endo/lysosomal escape and subsequent cytosolic release of dBET6. We demonstrate that USDPR is capable of effectively degrading BRD4 in a NIR light-controlled manner. This in combination with NIR light-triggered photodynamic therapy enables an enhanced antitumor effect both in vitro and in vivo. This work thus presents a versatile strategy for controlled release of PROTACs and codelivery with photosensitizers using an NIR-responsive nanodevice, providing important insight into the design of effective PROTAC-based combination therapy.

Restraining the power of Proteolysis Targeting Chimeras in the cage: A necessary and important refinement for therapeutic safety

Proteolysis Targeting Chimeras (PROTACs) represent a significant advancement in therapeutic drug development by leveraging the ubiquitin-proteasome system to enable targeted protein degradation, particularly impacting oncology. This review delves into the various types of PROTACs, such as peptide-based, nucleic acid-based, and small molecule PROTACs, each addressing distinct challenges in protein degradation. It also discusses innovative strategies like bridged PROTACs and conditional switch-activated PROTACs, offering precise targeting of previously "undruggable" proteins. The potential of PROTACs extends beyond oncology, with ongoing research and technological advancements needed to maximize their therapeutic potential. Future progress in this field relies on interdisciplinary collaboration and the integration of advanced computational tools to open new treatment avenues across various diseases.