No abstract

A novel drug delivery strategy featured with enhanced uptake of nanoparticles (NPs) by targeted tumor cells and subsequent intratumoral cellular hitchhiking of chemotherapy to deep tumor regions was described. The NP delivery system was obtained from assembly of poly(lactic acid-co-glycolic acid)-grafted hyaluronic acid (HA-g-PLGA) together with an anticancer drug, SN38, in aqueous phase, followed by implementing the NP surface with a layer of methoxypoly(ethylene glycol)-b-poly(histamine methacrylamide) (mPEG-b-PHMA) via hydrophobic association to improve the colloidal stability both in vitro and in vivo. Upon arrival of these PEGylated NPs at the acidic tumor site through the EPR effect, mPEG-b-PHMA became detached from the NP surface by the charge transition of the PHMA blocks from neutral (hydrophobic) to positively charged (hydrophilic) state via acid-induced protonation of their imidazole groups in tumor microenvironment. The exposure of HA shell on the naked NP thus resulted in enhanced uptake of NPs by CD44-expressed tumor cells, including cancer cells and tumor-associated macrophages (TAMs). Along with the TAMs being further chemotactically recruited by hypoxia cells, the engulfed nanotherapeutics was thus transported into the avascular area in which the anticancer action of chemotherapy occurred by virtue of the drug release alongside PLGA degradation, similar to those arising in other tumor nonhypoxia regions.

A new thieno­[3,2-b]­thiophene-incorporated acceptor TTC has been developed. The TTC acceptor was installed in a haptacyclic ladder-type core (BDCPDT) to furnish an n-type BDCPDT-TTC. The standard PBDB-T:BDCPDT-IC device showed a PCE of 9.33% with a V oc of 0.86 V and a J sc of 16.56 mA/cm2. By molecular engineering of the acceptor unit, the BDCPDT-TTC:PBDB-T-based device delivered an enhanced efficiency of 10.29% with a simultaneously enhanced V oc of 0.94 V and J sc of 17.72 mA/cm2. Incorporation of the electron-donating thieno­[3,2-b]­thiophene unit into the acceptor moiety decreases the electron-accepting strength, thereby upshifting the HOMO/LUMO energy levels to decrease the ΔE HOMO and E loss, achieving a larger V oc. Second, the extended conjugated bicyclic thieno­[3,2-b]­thiophene ring beneficially induces an additional optical transition at short wavelengths, leading to improvement of J sc. Alternatively, BDCPDT-FIC installed with the fluorinated acceptor shows more red-shifted absorption to achieve a high J sc of 19.12 mA/cm2.

No abstract

A formylated benzodi(cyclopentadithiophene) (BDCPDT) ladder-type structure with forced coplanarity is coupled with two 1,1-dicyanomethylene-3-indanone (IC) moieties via olefination to form a non-fullerene acceptor, BDCPDT-IC. The BDCPDT-IC, as an acceptor (A) with broad light-absorbing ability and excellent solution processability, is combined with a second PCBM acceptor (A) and a medium band gap polymer, PBDB-T, as the donor (D) to form a ternary blend with gradient HOMO/LUMO energy alignments and panchromatic absorption. The device with the inverted architecture using the D:A:A ternary blend has achieved a highest efficiency of 9.79% with a superior J of 16.84 mA cm.