RAFT Macro-Surfmers and Their Use in the ab Initio RAFT Emulsion Polymerization To Decouple Nanoparticle Size and Polymer Molecular Weight

Abstract

Polymeric nanoparticles (NPs) are highly engineered nanoemulsions with applications in several fields. The control over NP surface chemistry, size (Dn), and molecular weight (MW) of the polymer they are made up of plays a paramount role in the optimization of their end-use performance. In this work, the theoretical basis to decouple the dependence between the NP Dn and MW has been presented, and an operative way has been demonstrated via ab initio reversible addition−fragmentation chain transfer (RAFT) emulsion polymerization (AIREP), a "living" heterogeneous process that adopts RAFT macro-surfmers: macromolecular chain transfer agents (CTA) produced via RAFT polymerization of amphiliphic monomers, such as surfmers. The possibility of obtaining the desired length of the lipophilic block or the length of the whole block copolymer and the NP Dn by choosing the correct length of the RAFT macro-surfmer has been assessed. It has been discovered that a wide range of Dn and MW can be achieved, but not very big NPs with very low copolymer MW; this limit is consistent with the physical and geometric constraints of the system.

Self‐Assembling PCL‐Based Nanoparticles as PTX Solubility Enhancer Excipients

“…In this work, in order to reduce the complexity of the production of a less toxic formulation of PTX, biodegradable and biocompatible block‐copolymers with a peculiar comb‐like structure have been synthesized via the adoption of the reversible addition–fragmentation chain transfer (RAFT) polymerization. This “living” polymerization allows the control over the structure and molecular weight of the final copolymer and of the NP . In this way, in contrast to what happens for the common linear PCL‐PEG block‐copolymers, it is possible to control not only the length of the polyester portion, but also the number of the biodegradable lateral chains paving the way to a higher tunability of the system in terms of self‐assembling behavior, NP size, and NP degradation time .…”

“…This "living" polymerization allows the control over the structure and molecular weight of the final copolymer and of the NP. [15,16] In this way, in contrast to what happens for the common linear PCL-PEG block-copolymers, it is possible to control not only the length of the polyester portion, but also the number of the biodegradable lateral chains paving the way to a higher tunability of the system in terms of self-assembling behavior, NP size, and NP degradation time. [17,18] In particular, in order to avoid the storage issue of the NPs and the complex process of synthesis (e.g., T-mixer [19] ), a new method for the NP formation that requires only a syringe and a filter syringe was adopted.…”

Self‐assembling amphiphilic block copolymer from renewable δ‐decalactone and δ‐dodecalactone

“…It is also worth noting that this happens also for loaded micelles, where the particle size evolution was investigated for a suitable time for the release [the same of Fig. (a)] finally proving the efficiency of the added PEG chains to stabilize the polymers …”

“…5(a)] finally proving the efficiency of the added PEG chains to stabilize the polymers. 24,25 The micelles that were used for the release studies were also considered in relation to their potential cytotoxicity against 4T1 cells, derived from a mouse mammary tumor and well-characterized as a model for human breast cancer. 26 The SRB assay was employed reporting the survival of cells incubated with different micelles with respect to the control cells (where no polymer was added).…”

HPMA‐PEG Surfmers and Their Use in Stabilizing Fully Biodegradable Polymer Nanoparticles

“…The latter is a very important feature, since it assures the NPs a sufficient circulation time, thus allowing them to reach the target tissue . This justifies the widespread adoption of PEGMEMA surfmers for the stabilization of the so‐called “stealth” nanovectors . However, this kind of molecules cannot be bound to a bulk polyester obtained via ROP but must participate in a radical polymerization process to be incorporated in the growing polymer chains.…”