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Herein, the preparation of the cross‐linked copolymer hydrogels composed of various weight ratios of 2‐methacryloyloxyethyl phosphorylcholine (MPC) and 2‐hydroxyethyl methacrylate (HEMA) monomers employing free‐radical polymerization was reported. The integration of the MPC monomer into HEMA‐based hydrogels showed good transmittance (>90%) and enhanced the water content retention (79–202%) relative to those of pure HEMA‐based hydrogel. Notably, the MPC‐containing hydrogels (MPC‐H) exhibited the improved anti‐biofouling properties due to the formation of a compact hydration layer produced by the biomimetic MPC units at the hydrogel surface. MPC‐H exhibited a decrease in the bovine serum albumin (BSA) and lysozyme adsorption of approximately 40–70% and 44–65%, respectively, relative to those of control hydrogel without MPC monomer. The results presented herein demonstrate the potential of expending biocompatible monomers such as HEMA and MPC to efficiently generate a biomaterial that possesses both bio‐membrane mimicking character and protein and bacterial resistant properties for various industrial and biomedical applications. [ABSTRACT FROM AUTHOR]

In this work, antioxidant hydrogels were prepared by the construction of an interpenetrating chitosan network and functionalization with gallic acid. The poly(2-hydroxyethyl methacrylate) p(HEMA)-based hydrogels were first synthesized and subsequently surface-modified with an interpenetrating polymer network (IPN) structure prepared with methacrylamide chitosan via free radical polymerization. The resulting chitosan-IPN hydrogels were surface-functionalized with gallic acid through an amide coupling reaction, which afforded the antioxidant hydrogels. Notably, gallic-acid-modified hydrogels based on a longer chitosan backbone exhibited superior antioxidant activity than their counterpart with a shorter chitosan moiety; this correlated to the amount of gallic acid attached to the chitosan backbone. Moreover, the surface contact angles of the chitosan-modified hydrogels decreased, indicating that surface functionalization of the hydrogels with chitosan-IPN increased the wettability because of the presence of the hydrophilic chitosan network chain. Our study indicates that chitosan-IPN hydrogels may facilitate the development of applications in biomedical devices and ophthalmic materials. [ABSTRACT FROM AUTHOR]

The straightforward synthesis of three cationic boron-dipyrromethene (BODIPY) derivatives and their mitochondria-targeting and photodynamic therapeutic (PDT) capabilities are reported. Two cancer cell lines (HeLa and MCF-7) were used to investigate the PDT activity of the dyes. Compared to their non-halogenated counterparts, halogenated BODIPY dyes exhibit lower fluorescence quantum yields and enable the efficient production of singlet oxygen species. Following LED light irradiation at 520 nm, the synthesized dyes displayed good PDT capabilities against the treated cancer cell lines, with low cytotoxicity in the dark. In addition, functionalization of the BODIPY backbone with a cationic ammonium moiety enhanced the hydrophilicity of the synthesized dyes and, consequently, their uptake by the cells. The results presented here collectively demonstrate the potential of cationic BODIPY-based dyes as therapeutic drugs for anticancer photodynamic therapy. [ABSTRACT FROM AUTHOR]

• A synthetic strategy for the preparation of a series of dual functional triphenylphosphonium-functionalized BODIPY photosensitizers for mitochondria-targeted fluorescence bioimaging and photodynamic therapy (PDT) is reported. • The uniodinated BODIPY control displayed good biocompatibility, low cytotoxicity in the dark, and exceptional cellular imaging capabilities; however, it did not exhibit photodynamic therapeutic properties upon excitation at 530 nm. • Elevated levels of singlet oxygen (0.36–0.87) were generated by the iodinated BODIPY dyes, resulting in a significant cytotoxicity in cancer cells. • The iodinated BODIPY derivatives rendered adequate confocal fluorescence bioimages and mitochondria-targeting capabilities, despite the profound heavy atom effect induced by the two iodine atoms. • Overall, the results presented herein show the dual fluorescence-imaging and PDT dual functionality of the synthesized BODIPY dyes and demonstrate their considerable potential as viable agents for fluorescence-imaging-guided photodynamic therapy (PDT) for cancer treatment. Functionalization of BODIPY dyes with TPP substituents endowed them with mitochondria-targeting capabilities. The uniodinated BODIPY control displayed good biocompatibility, low cytotoxicity in the dark, and exceptional cellular imaging capabilities; however, it did not exhibit photodynamic therapeutic properties upon excitation at 530 nm. Dual functional photosensitizers were obtained in the case of mono- and di-iodinated BODIPY derivatives, which exhibited mitochondria-targeting capabilities and provided clear fluorescence confocal bioimages, while efficiently generating high levels of singlet oxygen species and displaying photodynamic therapeutic activity toward two cancer cell lines following LED irradiation. Overall, the results presented herein demonstrate the considerable potential for the use of TPP-functionalized BODIPY dyes as viable agents for fluorescence-imaging-guided photodynamic therapy (PDT) for cancer treatment. The synthesis of BODIPY-based photosensitizers exhibiting fluorescence-imaging and PDT dual functionality and the investigation of their photodynamic therapeutic activities were reported. Functionalization of the dyes with triphenylphosphonium (TPP) substituents endowed them with mitochondria-targeting capabilities. The uniodinated BODIPY control displayed good biocompatibility and exceptional cellular imaging capabilities. The iodinated BODIPY dyes exhibited mitochondria-targeting capabilities and provided clear fluorescence confocal bioimages, while efficiently generating high levels of singlet oxygen species and displaying photodynamic therapeutic activity toward two cancer cell lines following LED irradiation. The results presented herein demonstrate the considerable potential for the use of TPP-functionalized BODIPY dyes as viable agents for mitochondria-targeted fluorescence bioimaging and photodynamic therapy (PDT) applications [Display omitted]. [ABSTRACT FROM AUTHOR]

A series of hydrogels with intrinsic antifouling properties was prepared via surface-functionalization of poly(2-hydroxyethyl methacrylate) [p(HEMA)]-based hydrogels with the biomembrane-mimicking zwitterionic polymer, poly(2-methacryloyloxyethyl phosphorylcholine) [p(MPC)]. The p(MPC)-modified hydrogels have enhanced surface wettability, high water content retention (61.0%–68.3%), and good transmittance (>90%). Notably, the presence of zwitterionic MPC moieties at the hydrogel surfaces lowered the adsorption of proteins such as lysozyme and bovine serum albumin (BSA) by 73%–74% and 59%–66%, respectively, and reduced bacterial adsorption by approximately 10%–73% relative to the unmodified control. The anti-biofouling properties of the p(MPC)-functionalized hydrogels are largely attributed to the dense hydration layer formed at the hydrogel surfaces by the zwitterionic moieties. Overall, the results demonstrate that biocompatible and antifouling hydrogels based on p(HEMA)-p(MPC) structures have promising potential for application in biomedical materials. [ABSTRACT FROM AUTHOR]

ABSTRACT: A facile synthetic strategy was developed for the preparation of thermoresponsive nanocomposite hydrogels comprising crosslinked chitosan (CS) networks and poly(N‐isopropylacrylamide) [p(NIPAAm)] nanogels. First, thermoresponsive p(NIPAAm) nanogels were synthesized via emulsion polymerization. The p(NIPAAm) nanogels were introduced into methacrylamide CS (MC) solution and the free‐radical initiated crosslinking reaction of MC produced nanogel‐embedded hydrogels. The last step involves the loading of the antibacterial model drug levofloxacin (LFX) into the prepared nanocomposite hydrogels by allowing the preformed hydrogels to swell to equilibrium in the drug's aqueous solution. The integration of p(NIPAAm) nanogel into CS networks facilitates thermoresponsive release of LFX with an enhancement of the drug‐loading capacity within the hydrogel. Notably, thermoresponsive drug‐release was achieved without unwarranted modification of the hydrogel's dimension and shape, although an increase in temperature caused the collapse of the p(NIPAAm) nanogels. The thermoresponsive property of the investigated nanocomposite hydrogel is beneficial and may offer broad opportunities for drug temperature‐triggered release for clinical applications. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 1907–1914 [ABSTRACT FROM AUTHOR]

We report the modulation of the dual photo/thermo-responsive multicolor fluorescence from poly( N -isopropyl acrylate) pNIPAM-based nanogels. The thermo-responsive pNIPAM-crosslinked matrix was covalently copolymerized with nitrobenzoxadiazole (NBD) monomers as a Förster resonance energy transfer (FRET) donor and electrostatically conjugated with photochromic spiropyran (SP) dyes as a FRET acceptor. The pristine nanogel emits green fluorescence derived from the NBD moieties; however, the irradiation of the nanogels with UV light led to the transformation of the ring-closed colorless SP moieties to the ring-opened coral-red merocyanine (MC) moieties, resulting in light-pink fluorescent nanogels. Notably, at higher temperatures, the fluorescence of the nanogels was red-shifted and enhanced by the more efficient FRET process. The nanogels were well-distributed in the cellular cytoplasm and showed excellent photochromic function in the subcellular environment for applications as photo-switchable bio-imaging agents and nanothermometers. [ABSTRACT FROM AUTHOR]

A series of four lactose-modified BODIPY photosensitizers (PSs) with different substituents (-I, -H, -OCH3, and -NO2) in the para-phenyl moiety attached to the meso-position of the BODIPY core were synthesized; the photophysical properties and photodynamic anticancer activities of these sensitizers were investigated, focusing on the electronic properties of the different substituent groups. Compared to parent BODIPY H, iodine substitution (BODIPY I) enhanced the intersystem crossing (ISC) to produce singlet oxygen (1O2) due to the heavy atom effect, and maintained a high fluorescence quantum yield (ΦF) of 0.45. Substitution with the electron-donating methoxy group (BODIPY OMe) results in a significant perturbation of occupied frontier molecular orbitals and consequently achieves higher 1O2 generation capability with a high ΦF of 0.49, while substitution with the electron-withdrawing nitro group (BODIPY NO2) led a perturbation of unoccupied frontier molecular orbitals and induces a forbidden dark S1 state, which is negative for both fluorescence and 1O2 generation efficiencies. The BODIPY PSs formed water-soluble nanoparticles (NPs) functionalized with lactose as liver cancer-targeting ligands. BODIPY I and OMe NPs showed good fluorescence imaging and PDT activity against various tumor cells (HeLa and Huh-7 cells). Collectively, the BODIPY NPs demonstrated high 1O2 generation capability and ΦF may create a new opportunity to develop useful imaging-guided PDT agents for tumor cells. [ABSTRACT FROM AUTHOR]

Triphenylphosphonium (TPP) cations endow fluorophores with improved hydrophilicities and mitochondria targeting abilities. Evidently, the number of cationic moieties can influence the behavior of fluorophores in different environments. Two water-soluble BODIPY fluorophores, 3TPP and 5TPP , were constructed with three and five TPP groups, respectively, in their structure. Both showed maximum absorption and emission at 640–700 nm wavelengths; however, 5TPP showed a fluorescence quantum yield 10 times higher than that of 3TPP in an aqueous medium, highlighting the beneficial effect of two additional TPP groups on the photophysical properties. While both fluorophores showed excellent stabilities and mitochondrial imaging abilities with low cytotoxicities in HeLa and MCF-7 cells, 5TPP permeated into the mitochondria better than 3TPP. Interestingly, 5TPP demonstrated a 90-fold increase in "turn-on" fluorescence in the presence of bovine serum albumin (BSA) in relation to that of four other proteins (i.e., lysozyme, esterase, transferrin, and fibrinogen). Notably, the fluorescence intensity of 5TPP increased with increasing BSA concentration. The present work is the first report on BODIPY sensors with multiple bulky cationic moieties and provides insights on the applicability of 5TPP as a novel biomaterial for mitochondrion tracking and light-up fluorescence protein sensing. • BODIPY-based fluorophores, 3TPP and 5TPP , were conjugated with three and five (triphenylphosphonium) TPP groups, respectively. • Both fluorophores showed excellent photostabilities and mitochondrial imaging abilities with low cytotoxicities in HeLa and MCF-7 cells. • 5TPP exhibited a 90-fold increase in "turn-on" fluorescence in the presence of bovine serum albumin (BSA) with respect to that of four other proteins (i.e., lysozyme, esterase, transferrin, and fibrinogen). [ABSTRACT FROM AUTHOR]