Controlled Formation of Star Polymer Nanoparticles via Visible Light Photopolymerization

Star Polymers

“…The reported system is therefore particularly attractive to large-scale synthesis of biocompatible polymers, as the polymerization may take place in the absence of solvents, i.e., under "green" and industrially relevant conditions, and the product polymers would contain negligible amounts of metal zinc due to low catalyst loadings. Later, the same authors reported the synthesis of well-defined three-arm star polymer P(TMC) 3 73 and copolymer P(TMC-b-L-lactide(LLA)) 3 74 through the Zn(II)-mediated ROP via a core-first approach. Their studies demonstrated the synthetic versatility and potential application of the new catalytic system in producing biocompatible and biodegradable polymers for drug delivery and medical implant applications.…”

“…As a result, the Fe(dbmOH) 3 -mediated ROP of LA was fast and highly efficient, and it afforded welldefined triarm metal complex star polymers in excellent purity and yield (Figure 12b and 12c). Given the functional features of Fe(dbm) 3 complex (including chromophores, pH-responsive linker, and potential bioactive agents in cancer therapy) and the biocompatibility and biodegradability of PLA, the resultant metal complex star (i.e., Fe(dbm-PLA) 3 ) may be further explored as stimuli-responsive luminescent materials for drug delivery and medical imaging applications. Demetalation of the star via acid treatment may liberate dbm end-functionalized linear PLA as a dual-emissive polymer, which exhibits both fluorescence and rare room-temperature phosphorescence in the solid state.…”

“…103,104 The miktoarm star polymers are composed of rigid poly(n-hexyl isocyanate) (PHIC) and soft aliphatic polyester PLLA (or PCL), serving as the A and B segments, respectively. Synthesis of the AB 2 and AB 3 stars was achieved through the click coupling of the azido chain end-functional PHIC (PHIC-N 3 ) with ethynyl-functionalized alcohols yielding di-or trihydroxyl end-functionalized PHICs (PHIC-(OH) 2 and PHIC-(OH) 3 ), followed by the ROP of LA (or CL) using PHIC-(OH) 2 and PHIC-(OH) 3 as the macroinitiators, respectively. Self-assembly studies found the AB 2 and AB 3 miktoarm star polymers (i.e., PHIC-(PCL or PLLA) 2 and PHIC-(PCL or PLLA) 3 ) as well as the corresponding linear analogue (i.e., PHIC-PCL (or PLLA)) forms spherical micelles in DMF.…”

“…Synthesis of the AB 2 and AB 3 stars was achieved through the click coupling of the azido chain end-functional PHIC (PHIC-N 3 ) with ethynyl-functionalized alcohols yielding di-or trihydroxyl end-functionalized PHICs (PHIC-(OH) 2 and PHIC-(OH) 3 ), followed by the ROP of LA (or CL) using PHIC-(OH) 2 and PHIC-(OH) 3 as the macroinitiators, respectively. Self-assembly studies found the AB 2 and AB 3 miktoarm star polymers (i.e., PHIC-(PCL or PLLA) 2 and PHIC-(PCL or PLLA) 3 ) as well as the corresponding linear analogue (i.e., PHIC-PCL (or PLLA)) forms spherical micelles in DMF. The sizes of micelles prepared from copolymers of the same compositions and MWs decrease with increasing arm number of the polyester chains (i.e., PCL or PLLA) due to the excluded volume effect of the polyester domain ( Figure 24).…”

Recent Advances of Light-Mediated Theranostics

“…In order to overcome these challenges, another commonly used strategy based on visible light-mediated strategy, which can cause less damage than UV light in living system, has been proposed as an alternative to light-activated therapeutic studies. Until now, a variety of visible light responsive organic moieties, such as vitamin B 12 derivatives 62-64, trithiocarbonates 65, 66 etc., have been utilized for visible light-mediated drug delivery. For instance, Lawrence's group have reported a series of vitamin B 12 derivatives for tuneable visible light-controlled drug activation and bioimaging in living cells (Figure 4A) 63.…”