H_(2)O_(2)-Responsive Injectable Polymer Dots Hydrogel for Long-term Photodynamic Therapy of Tumors

Photodynamic therapy(PDT)has been emerged as a promising modality for cancer treatment.However,the development of drug delivery system enabling continuous release of photosensitizers(PSs)for long-term PDT treatment still remains challenges.Herein,a H_(2)O_(2)-responsive injectable hydrogel,covalently crosslinked by N^(1)-(4-boronobenzyl)-N^(3)-(4-boronophenyl)-N^(1),N^(1),N^(3),N^(3)-tetramethylpropane-1,3-diaminium(TSPBA)with PVA containing polythiophene quaternary ammonium salt(PT2)polymer dots(PDots)as a photosensitizer was fabricated.Under the stimulation of H_(2)O_(2),the obtained injectable hydrogel gradually degrades and releases PDots.In vitro experiments suggested that the released PDots could realize efficient tumor cells inhibition through its robust singlet oxygen generation capability upon 577 nm laser irradiation.In vivo studies demonstrated a sustained retention of PDots for at least 7 days following single-dose administration,facilitating efficient tumor inhibition with light treatments for 3 times without apparent biotoxicity.This work presents an innovative polymer dots-based composite local drug delivery system for long-term PDT in cancer treatment.

Mainchain Semifluorinated Polymers with Ultra High Molecular Weight via Reaction-enhanced Reactivity of Intermediate(RERI) Mechanism

Achieving the linear polymers with high molecular weight via step-growth polymerization of A2 and B2 monomers is significantly limited by the requirement of strict stoichiometry of two monomers when the reactivity of A and B groups are not changed during the polymerization.Herein,a unique step-growth polymerization based on copper-catalyzed azide-alkyne cycloaddition(CuAAC)with reactionenhanced reactivity of intermediate(RERI)mechanism was developed for the preparation of mainchain semifluorinated polymers with high molecular weight.The CuAAC polymerization of bis-alkynyl-terminated fluorinated monomers(A2)and 2,2-bis(azidomethyl)propane-1,3-diyl bis(2-methylpropanoate)(BiAz,B2)with RERI effect at different stoichiometric ratio was systematically investigated.The results indicated that the semifluorinated polymers with ultrahigh molecular weight,Mw,MALLS>106 g/mol,could be efficiently synthesized by using excess molar of BiAz monomers.The resultant high-molecular-weight semifluorinated polymers show good thermostability and high hydrophobicity.In addition,the glass transition temperature(Tg)of these mainchain semifluorinated polymers could be tuned conveniently due to the bis-alkynyl-terminated comonomers could be consumed completely when excessive BiAz monomers were used in this this step-growth polymerization.

Porphyrin-based Nanosonosensitizers Combined with Targeting Peptides for Sonodynamic Therapy of Glioma

Traditional cancer treatments have disadvantages of large trauma area and toxic side effects while killing cancer cells.Peptide-targeted sonodynamic therapy(SDT)can effectively improve specificity of cancer treatment and overcome the problem of low tissue penetration depth caused by a photo-driven therapy.Herein,we developed a porphyrin-based sonosensitizer with a water-soluble polymer as a biological carrier and a cRGD peptide for tumor targeting,which constituted a nano sonosensitizer(T-cRGD NPs)for fluorescence imaging-guided sonodynamic therapy.A comparable sonosensitizer(T-PEG NPs)without the targeting unit was also prepared for illustration of therapeutic performance.Attribute to the role of peptide targeting,T-cRGD NPs can accumulate and enter tumor cells for fluorescence imaging and show a superior SDT effect than T-PEG NPs in vitro.The imaging in vivo reveals that T-cRGD NPs can enrich in tumor tissues within 14 h with a good biocompatibility.

COLORIMETRIC DETECTION OF CARBENICILLIN USING CATIONIC POLYTHIOPHENE DERIVATIVES

A water-soluble, polythiophene-based colorimetric sensor was designed for selective and sensitive detection of carbenicillin in HEPES buffer solution. Quaternized quinine was linked to thiophene through bis-functionality benzyl group, which can interact with carbenicillin via electrostatic interaction and geometric match effect. The sensor exhibited a colorimetric signal change upon the addition of carbenicillin because of the formation of more nonplanar structures. However, the addition of other beta-lactarn antibiotics or dicarboxylic acids into the sensor solution caused no obvious changes in absorbance intensity ratio. This result may be attributed to the cavity formed by the semi-rigid framework of PTQ2, which is suitable for the special binding with carbenicillin. This novel sensor can effectively distinguish carbenicillin from other beta-lactam antibiotics and has a wide linear range response in HEPES buffer solution. Linear calibration curves are obtained with 0 to 18 μmol/L of HEPES buffer solution, with a limit of detection of 0.54μmol/L.