An elegant integration of light-emitting segments into the structure of polymeric delivery systems endows the resulting self-assembled nanovehicles with the diagnostic ability toward an enhanced therapeutic efficiency. A variety of polyfluorene (PF)-based binary delivery systems were designed and developed successfully, but PF-based ternary formulations remain rarely explored, likely due to the synthetic challenge. To develop a universal synthesis strategy toward linear conjugated amphiphilic triblock copolymer for cancer theranostics, herein we focused on the functionalization of the PF terminus for further chain extension and prepared well-defined PF-based amphiphilic triblock copolymers, PF-bpoly(ε-caprolactone)-b-poly(oligo(ethylene glycol) monomethyl ether methacrylate) (PF-b-PCL-b-POEGMA), by integrated state-of-the-art polymer chemistry techniques, including Suzuki reaction, ring-opening polymerization, atom transfer radical polymerization, and click coupling. The resulting conjugated amphiphilic triblock copolymers can self-assembe into core−shell-corona (CSC) micelles with PF block constructing the inner hydrophobic core for fluorescent tracking, PCL segment forming the hydrophobic middle shell for drug encapsulation, and POEGMA moiety building the hydrophilic outer corona for particulate stabilization. Interestingly, the CSC micelles with hydrophobic PCL middle layer show a greater drug loading capacity as well as a higher fluorescence quantum yield (Φ) relative to the core−shell micelles self-assembled from the control of PF-b-POEGMA diblock copolymers without PCL sequence due to having more hydrophobic spaces and better separation of PF sequence provided simultaneously by the PCL central block. The efficient cellular uptake of the anticancer drug doxorubicin-loaded CSC micelles together with the in vitro cytotoxicity against the HeLa cells makes the conjugated amphiphilic triblock copolymers developed herein a promising platform for simultaneous cell image and drug delivery, thus offering great potential for cancer theranostics.

A widely used strategy for simulating the charge transfer between donor and acceptor electronic states in an all-atom anharmonic condensed-phase system is based on invoking linear response theory to describe the system in terms of an effective spin-boson model Hamiltonian. Extending this strategy to photoinduced charge transfer processes requires also taking into consideration the ground electronic state in addition to the excited donor and acceptor electronic states. In this paper, we revisit the problem of describing such nonequilibrium processes in terms of an effective three-state harmonic model. We do so within the framework of nonequilibrium Fermi’s golden rule (NE-FGR) in the context of photoinduced charge transfer in the carotenoid–porphyrin–C60 (CPC60) molecular triad dissolved in explicit tetrahydrofuran (THF). To this end, we consider different ways for obtaining a three-state harmonic model from the equilibrium autocorrelation functions of the donor–acceptor, donor–ground, and acceptor–ground energy gaps, as obtained from all-atom molecular dynamics simulations of the CPC60/THF system. The quantum-mechanically exact time-dependent NE-FGR rate coefficients for two different charge transfer processes in two different triad conformations are then calculated using the effective three-state model Hamiltonians as well as a hierarchy of more approximate expressions that lead to the instantaneous Marcus theory limit. Our results show that the photoinduced charge transfer in CPC60/THF can be described accurately by the effective harmonic three-state models and that nuclear quantum effects are small in this system.

The Fenna−Matthews−Olson (FMO) complex of green sulfur bacteria has been serving as a prototypical lightharvesting protein for studying excitation energy transfer (EET) dynamics in photosynthesis. The most widely used Frenkel exciton model for FMO complex assumes that each excited bacteriochlorophyll site couples to an identical and isolated harmonic bath, which does not account for the heterogeneous local protein environment. To better describe the realistic environment, we propose to use the recently developed multistate harmonic (MSH) model, which contains a globally shared bath that couples to the different pigment sites according to the atomistic quantum mechanics/molecular mechanics simulations with explicit protein scaffold and solvent. In this work, the effects of heterogeneous protein environment on EET in FMO complexes from Prosthecochloris aestuarii and Chlorobium tepidum, specifically including realistic spectral density, site-dependent reorganization energies, and system−bath couplings are investigated. Semiclassical and mixed quantum-classical mapping dynamics were applied to obtain the nonadiabatic EET dynamics in several models ranging from the Frenkel exciton model to the MSH model and their variants. The MSH model with realistic spectral density and site-dependent system−bath couplings displays slower EET dynamics than the Frenkel exciton model. Our comparative study shows that larger average reorganization energy, heterogeneity in spectral densities, and low-frequency modes could facilitate energy dissipation, which is insensitive to the static disorder in reorganization energies. The effects of the spectral densities and system−bath couplings along with the MSH model can be used to optimize EET dynamics for artificial light-harvesting systems.