A Novel PEtOx-Based Nanogel Targeting Prostate Cancer Cells for Drug Delivery

This study focuses on creating a specialized nanogel for targeted drug delivery in cancer treatment, specifically targeting prostate cancer. This nanogel (referred to as SGK 636/Peptide 563/PEtOx nanogel) is created using hydrophilic poly(2-ethyl-2-oxazoline) (PEtOx) through a combination of living/cationic ring-opening polymerization (CROP) and alkyne-azide cycloaddition (CuAAC) "click" chemical reactions. A fluorescent probe (BODIPY) is also conjugated with the nanogel to monitor drug delivery. The characterizations through 1 H-NMR, and FT-IR, SEM, TEM, and DLS confirm the successful production of uniform, and spherical nanogels with controllable sizes (100 to 296 nm) and stability in physiological conditions. The biocompatibility of nanogels is evaluated using MTT cytotoxicity assays, revealing dose-dependent cytotoxicity. Drug-loaded nanogels exhibited significantly higher cytotoxicity against cancer cells in vitro compared to drug-free nanogels. Targeting efficiency is examined using both peptide-conjugated and peptide-free nanogels, with the intracellular uptake of peptide 563-conjugated nanogels by tumor cells being 60-fold higher than that of nanogels without the peptide. The findings suggest that the prepared nanogel holds great potential for various drug delivery applications due to its ease of synthesis, tunable functionality, non-toxicity, and enhanced intracellular uptake in the tumor region.

A robust optimization approach for the breast cancer targeted design of PEtOx-b-PLA polymersomes

The equipping of nanoparticles with the peptide moiety recognizing a particular receptor, enables cell or tissue-specific targeting, therefore the optimization of the targeted nanoparticles is a key factor in the formulation design process. In this paper, we report the optimization concept of Doxorubicin encapsulating PEtOx-b-PLA polymersome formulation equipped with Peptide18, which is a breast cancer recognizing tumor homing peptide, and the unveiling of the cell-specific delivery potential. The most dominant formulation parameters, which are the polymer to Doxorubicin mass ratio (w/w) and the aqueous to organic phase ratio (v/v), were optimized using Central Composite Design (CCD) based Response Surface Methodology. The characteristics of optimum polymersome formulation were determined as the hydrodynamic diameter of 146.35 nm, the PDI value of 0.136, and the encapsulation efficiency of 57.11% and TEM imaging, which are in agreement with the DLS data, showed the spherical morphology of the polymersomes. In order to demonstrate the breast cancer-specific delivery of targeted polymersomes, the flow cytometry and confocal microscopy analyses were carried out. The targeted polymersomes were accumulated 8 times higher in AU565 cells compared to MCF10A cells and the intracellular Doxorubicin was almost 10 times higher in AU565 cells. The CCD-mediated optimized targeted polymersomes proposed in this report holds the promise of targeted therapy for breast cancer and can be potentially used for the development of novel treatments.

Dual Site-Specific Chemoenzymatic Antibody Fragment Conjugation Using CRISPR-Based Hybridoma Engineering

Functionalized antibodies and antibody fragments have found applications in the fields of biomedical imaging, theranostics, and antibody–drug conjugates (ADC). In addition, therapeutic and theranostic approaches benefit from the possibility to deliver more than one type of cargo to target cells, further challenging stochastic labeling strategies. Thus, bioconjugation methods to reproducibly obtain defined homogeneous conjugates bearing multiple different cargo molecules, without compromising target affinity, are in demand. Here, we describe a straightforward CRISPR/Cas9-based strategy to rapidly engineer hybridoma cells to secrete Fab′ fragments bearing two distinct site-specific labeling motifs, which can be separately modified by two different sortase A mutants. We show that sequential genetic editing of the heavy chain (HC) and light chain (LC) loci enables the generation of a stable cell line that secretes a dual tagged Fab′ molecule (DTFab′), which can be easily isolated. To demonstrate feasibility, we functionalized the DTFab′ with two distinct cargos in a site-specific manner. This technology platform will be valuable in the development of multimodal imaging agents, theranostics, and next-generation ADCs.

Poly(2-ethyl-2-oxazoline-co-ethyleneimine)-block-poly(ε-caprolactone) based micelles: synthesis, characterization, peptide conjugation and cytotoxic activity

Here we present self-assembled polymeric micelles as potential delivery systems for therapeutic agents with highly tunable properties.