Engineering glutathione-responsive near-infrared polymeric prodrug system for fluorescence imaging in tumor therapy

Zwitterionic Internalizable Peptide-Drug Conjugates: Tumor-Selective Ultrafast Uptake and Transcytosis for Enhanced Antitumor Therapy

Here a novel class of zwitterionic internalizable peptide (ZIP)-drug conjugates is presented. The conjugates incorporate γ-glutamyl-α-aminobutyrylamino-functionalized lysine peptides as the ZIP backbones and disulfide-linked camptothecin (CPT) as the toxic payload. The ZIPs significantly enhance the water solubility of CPT without compromising its cytotoxicity. Cellular uptake profiling shows ultrafast internalization of the conjugates in tumor cells within 5 min. Mechanistic studies reveal that they enter cells via lipid raft-mediated pathways, involving both energy-driven active transport and membrane fluidity-dependent passive uptake. Furthermore, these conjugates exhibit robust transcytosis abilities across dense cell monolayers and tumor spheroids. These characteristics confer prolonged blood circulation, enhanced tumor accumulation, and deep tumor penetration on the conjugates, which result in potent in vivo antitumor activity and minimal systemic toxicity. This study underscores the potential of the conjugates for safer and more effective cancer therapies and presents ZIPs as a new category of molecularly defined delivery tools for biomedical applications.

Camptothecin-based prodrug nanomedicines for cancer therapy

Camptothecin (CPT) is a cytotoxic alkaloid that attenuates the replication of cancer cells via blocking DNA topoisomerase 1. Despite its encouraging and wide-spectrum antitumour activity, its application is significantly restricted owing to its instability, low solubility, significant toxicity, and acquired tumour cell resistance. This has resulted in the development of many CPT-based therapeutic agents, especially CPT-based nanomedicines, with improved pharmacokinetic and pharmacodynamic profiles. Specifically, smart CPT-based prodrug nanomedicines with stimuli-responsive release capacity have been extensively explored owing to the advantages such as high drug loading, improved stability, and decreased potential toxicity caused by the carrier materials in comparison with normal nanodrugs and traditional delivery systems. In this review, the potential strategies and applications of CPT-based nanoprodrugs for enhanced CPT delivery toward cancer cells are summarized. We appraise in detail the chemical structures and release mechanisms of these nanoprodrugs and guide materials chemists to develop more powerful nanomedicines that have real clinical therapeutic capacities.

Update of ultrasound-assembling fabrication and biomedical applications for heterogeneous polymer composites

As a power-driving approach, ultrasound irradiation is very appealing to the preparation or modification of new materials. In the review, we overviewed the latest development of ultrasound-mediated effects or reactions in polymer composites, and demonstrated its unique and powerful aspects on the polymerization or aggregation. The review generalized the different categories of heterogeneous polymer composites by defining the constituents, and described the shapes, sizes and basic properties of various purpose-specific or site-specific products. Importantly, the review paid more attention to the main biomedicine applications of heterogeneous polymer composites, such as drug or bioactive substance entrapment, delivery, release, imaging, and therapy, and emphasized many advantages of ultrasound-assembling approaches and heterogeneous polymer composites in biology and medicine fields. In addition, the review also indicated the prospective challenges of heterogeneous polymer composites both in ultrasound-assembling designs and in biomedical applications.