Synthesis and characterization of a PAMAM-OH derivative containing an acid-labile β-thiopropionate bond for gene delivery

Effect of the Folate Ligand Density on the Targeting Property of Folated‐Conjugated Polymeric Nanoparticles

“…This could be fulfilled through the selective and specific interaction between the folate group on the surface of FA‐F127‐PCL nanoparticles and the folate receptor on the surface of OVCAR‐3 cells. The targeted PTX‐loaded FA‐P85‐PCL nanoparticles shows similar specific targeting behavior (see Figure B) …”

Targeted delivery by pH-responsive mPEG-S-PBLG micelles significantly enhances the anti-tumor efficacy of doxorubicin with reduced cardiotoxicity

“…It is reported that some pH-responsive linkages, such as acetal linkages, are highly sensitive to acid condition, resulting in rapid breakdown of linkage and burst release of drugs from NPs (more than 50%) at lower pH in the first 24 h (Kim et al., 2009 ; Shim & Kwon, 2012 ; Tu et al., 2013 ). It should be noted that compared with other pH responsive NPs, the initial drug release from mPEG-S-PBLG micelles in response to pH stimulus was relatively slow (less than 20% and 40% drugs were released at pH 6.5 and 5.0 during 24 h) due to the lower degradation rate of β-thiopropionate linkage under acidic conditions than other acid-labile functional groups (Chen et al., 2016 ; Pramanik et al., 2016 ). The micellar formulation also increased the cellular uptake of DOX at pH 6.5 due to the cleavage of β-thiopropionate linkage, allowing the extensive DOX release.…”

Design of Smart Size‐, Surface‐, and Shape‐Switching Nanoparticles to Improve Therapeutic Efficacy

“…Responsiveness is typically observed as a result of bond cleavage and/or functional group protonation in the described acidic microenvironments to trigger the targeted physical property (size, surface, or shape) changes, examples of which are listed in Table 1 . Cleavable bonds such as hydrazones or anhydrides can be incorporated into the nanoparticle and subsequently degraded when exposed to the corresponding acidic microenvironment; [ 8,22,26,41,43,65–82 ] for example, the use of anhydrides to amidize amine groups for charge switching was first described in 2007 by the Kataoka and Shen groups. [ 83,84 ] Alternatively, methods that employ protonation typically involve the addition of H + to functional groups to convert the net charge or the hydrophobicity/hydrophilicity of the nanoparticle, [ 12,42,66,85–105 ] thus promoting nanoparticle penetrability/uptake and/or nanoparticle destabilization to form aggregates that deposit drug at the target site.…”