POxylated Polyurea Dendrimers: Smart Core-Shell Vectors with IC₅₀Lowering Capacity

Abstract

The design and preparation of highly efficient drug delivery platforms using green methodologies is at the forefront of nanotherapeutics research. POxylated polyurea dendrimers are efficiently synthesized using a supercritical-assisted polymerization in carbon dioxide. These fluorescent, pH-responsive and water-soluble core-shell smart nanocarriers show low toxicity in terms of cell viability and absence of glutathione depletion, two of the major side effect limitations of current vectors. The materials are also found to act as good transfection agents, through a mechanism involving an endosomal pathway, being able to reduce 100-fold the IC50 of paclitaxel.

Supercritical CO2-Assisted Spray Drying of Strawberry-Like Gold-Coated Magnetite Nanocomposites in Chitosan Powders for Inhalation

“…Figure 4 shows both the emission and excitation spectra of POxylated nanoparticles. The representative bands of POx-SH are maintained after particle grafting (λ exc = 300; λ emm = 384 nm) [26,27,42]. …”

“…POXylation (grafting with oligo(2-ethyl-oxazolines), a similar strategy to PEGylation, currently under investigation to circumvent PEG hepatoxicity issues, has also been employed. Besides the ability to protect nanoparticles, POXylation also add fluorescent capabilities to the nanoparticles enabling an in vitro real time analysis of particles’ course within cell environments [26,27,28]. However, nanoparticles are not in a suitable size for deep lung deposition, as they can be easily exhaled or muccociliary cleared out [29].…”

“…This mechanism is represented in Figure 1. Additionally, IBP was encapsulated to evaluate if this system can be used as a synergetic platform [27,32]. The final nano-in-micro drug delivery system is herein studied as a proof-of-concept and therefore, in order to understand the effectiveness of this system, a more detailed study is being taken by our group to prove its viability.…”

Molecular Weight Determination by Luminescent Chemo–enzymatics

“…This transformation was used to detect urea in urine by a phosphorescence sensor based on manganese doped zinc sulfide QDs . Polyureas are an important class of polymers, with applications in many fields, particularly, emergent polyurea dendrimers and their branched and hyperbranched counterparts . In this work, we investigated the molecular weight determination by enzymatic degradation using polyurea dendrimers as a case study, but linear and crosslinked polymers are envisaged to be suitable materials to investigate using this methodology.…”

POxylated Dendrimer‐Based Nano‐in‐Micro Dry Powder Formulations for Inhalation Chemotherapy

“…We also demonstrated that polyurea dendrimer nanoparticles POxylated using hydrophilic oligo‐oxazolines triggered a 100‐fold reduction in the median inhibitory concentration (IC 50 ) value of PTX relative to what was found in the free drug. This strategy was extended to the chemotherapeutic nano‐in‐micro dry powder formulations (DPFs) designed in this work . The synergies between nano‐ and microparticles ensure a quick delivery to the lung and enhance drug accumulation in neoplastic cells, which allow for: a faster response to the drug, a reduction in drug dosage, and consequently, a decrease in the number of undesired side effects.…”