PATENTS:
Lee, J.-J.; Jeong, K. J., A Multi-Function Contact Lens for Ocular Diseases. 2018, U.S. Patent: 62/691,774
Lee, J.-J., Storable, Thermally Activated, Near-Infrared Fluorescent and Chemiluminescent Nanoparticles, 2018, U.S. Patent:62/746,383
Lee, J.-J.; Jeong, K. J.; Kohane, D. S., Magnetic Separation using Nanoparticles. 2014, U.S. Patent: 14/167,773
UNDER REVIEW:
Kim, K., Ryu, T., Kaur, R., Watanabe, S., Oweida, A., Lee, M., Lepez, C., Stoykova, G. E., Karam, S. D. & Lee, J.J., Body Heat-Activated Near-Infrared Chemiluminescent Chitosan-Based Nanoparticles for Image-Guided Head and Neck Cancer Surgery.
Nat. Biomed. Eng., doi.org/10.6084/m9.figshare.23522148, (under review)
IN PREPARATION:
Vong, S., Arai, E., Morris, M., Lee, M., Jeong, K. J., & Lee, J.J., Matrix Metalloproteinase-Deactivating Porous Contact Lens for Chemical Burns, Adv. Healthc. Mater. (In Preparation)
Ryu, T., Vong, S., Stoykova, G. E., Lee, M., Okhovat, A., Shim, J., & Lee, J.J. Self-chemiluminescent Nanoparticles for In Vivo Optical Imaging of Prostate Cancer. Nanomedicine. (In Preparation)
Rwei, A., Shankarappa, S. A., Tsui, J. H., Lee, M., Okhovat, A., Shim, J., & Lee, J.J. Synthesis and Sugar-Sensitivity Study of Boronated Crosslinked Glycopolymer Nanoparticles. New J. Chem. (In Preparation)
Ryu, T., Oweida, A., Arai, E., Lee, M. & Lee, J.J. Real-Time Imaging of ROS-Activated Self-Illuminating Nanoparticles in Prostate Cancer Imaging. Nanomaterials. (In Preparation)
PEER REVIEWED ARTICLES:
2021 Piper, M., Van Court, B., Mueller, A., Watanabe, S., Bickett, T., Bhatia, S., Darragh, L.B., Mayeda, M., Nguyen, D., Gadwa, J., Knitz, M., Corbo, S., Morgan, R., Lee, J.J., Dent, A., Goodman, K., Messersmith, W., Schulick, R., Del Chiaro, M., Zhu, Y., Kedl, R.M., Lenz, L. & Karam, S.D. Targeting Treg-expressed STAT3 enhances NK-mediated surveillance of metastasis and improves therapeutic response in pancreatic adenocarcinoma. Clin. Cancer. Res., 28 (5), 1013-1026.
We demonstrate that although radiotherapy increases the infiltration and activation of dendritic cells (DC), it also increases the infiltration of regulatory T cells (Treg) while failing to recruit natural killer (NK) and CD8 T cells in PDAC patient tissue samples. In murine orthotopic tumor models, we show that genetic and pharmacologic depletion of Tregs and NK cells enhances and attenuates response to radiotherapy, respectively. We further demonstrate that targeted inhibition of STAT3 on Tregs results in improved control of local and distant disease progression and enhanced NK-mediated immunosurveillance of metastasis. Moreover, combination treatment of STAT3 antisense oligonucleotide (ASO) and radiotherapy invigorated systemic immune activation and conferred a survival advantage in orthotopic and metastatic tumor models. Finally, we show the response to STAT3 ASO + radiotherapy treatment is dependent on NK and DC subsets.
2021 Kim, K.N., Oh, K.S., Shim, J., Schlaepfer, I.R., Karam, S.D. & Lee, J.J. Light-Responsive Polymeric Micellar Nanoparticles with Enhanced Formulation Stability. Polymers, 13 (3), 67-83.
Light-sensitive polymeric micelles have recently emerged as promising drug delivery systems for spatiotemporally controlled release of payload at target sites. Here, we developed diazonaphthoquinone (DNQ)-conjugated micellar nanoparticles that showed a change in polarity of the micellar core from hydrophobic to hydrophilic under UV light, releasing the encapsulated anti-cancer drug, doxetaxel (DTX). The micelles exhibited a low critical micelle concentration and high stability in the presence of bovine serum albumin (BSA) solution due to the hydrophobic and π-π stacking interactions in the micellar core. Cell studies showed enhanced cytotoxicity of DTX-loaded micellar nanoparticles upon irradiation. The enhanced stability would increase the circulation time of the micellar nanoparticles in blood, and enhance the therapeutic effectiveness for cancer therapy.
2019 Lopez, C., Park, S., Edwards, S., Vong, S., Hou, S., Lee, M., Sauerland, H., Lee, J.J.* & Jeong, K.J.*Matrix Metalloproteinase-Deactivating Contact Lens for Corneal Melting. ACS Biomater. Sci. Eng., 5, 1195-1199.
Corneal melting is an uncontrolled, excessive degradation of cellular and extracellular components of the cornea. This potential cause of corneal blindness is caused by excessive expression of zinc-dependent matrix metalloproteinases (MMPs) and has no satisfying cure as of now. Herein, we introduce a novel therapeutic hydrogel that can be made into a contact lens to slow down the progression of corneal melting by deactivating MMPs. The hydrogel backbone is comprised of poly(2-hydroxyetyl methacrylate) (pHEMA), a main material for commercial contact lenses, and dipicolylamine (DPA), which has high affinity for and selectivity toward zinc ion. As a result, the DPA-conjugated pHEMA (pDPA-HEMA) hydrogel selectively removes zinc ions from a physiological buffer and deactivates MMP-1, MMP-2, and MMP-9 within 2 h. pDPA-HEMA hydrogel also effectively prevents degradation of porcine corneas by collagenase A, a zinc-dependent protease, whereas the cornea completely degrades within 15 h when incubated with pHEMA hydrogel. The presence of pDPA-HEMA hydrogel does not affect the viability of keratocytes and corneal epithelial cells. Unlike the conventional MMP inhibitors (MMPi), the pDPA-HEMA hydrogel minimizes the risk of serious nonspecific side effects and provides a method to slow down the progression of corneal melting and other related ocular diseases.
2015 Rwei, A.Y., Lee, J.J., Zhan, C., Liu, Q., Ok, M.T., Shankarappa, S.A., Langer, R. & Kohane, D.S. Repeatable and adjustable on-demand sciatic nerve block with phototriggerable liposomes. Proc. Natl. Acad. Sci. U. S. A., 112, 15719-15724.
Pain management would be greatly enhanced by a formulation that would provide local anesthesia at the time desired by patients and with the desired intensity and duration. To this end, we have developed near-infrared (NIR) light-triggered liposomes to provide on-demand adjustable local anesthesia. The liposomes contained tetrodotoxin (TTX), which has ultrapotent local anesthetic properties. They were made photo-labile by encapsulation of a NIR-triggerable photosensitizer; irradiation at 730 nm led to peroxidation of liposomal lipids, allowing drug release. In vitro, 5.6% of TTX was released upon NIR irradiation, which could be repeated a second time. The formulations were not cytotoxic in cell culture. In vivo, injection of liposomes containing TTX and the photosensitizer caused an initial nerve block lasting 13.5 ± 3.1 h. Additional periods of nerve block could be induced by irradiation at 730 nm. The timing, intensity, and duration of nerve blockade could be controlled by adjusting the timing, irradiance, and duration of irradiation. Tissue reaction to this formulation and the associated irradiation was benign.
2014 Lee, J.J., Jeong, K.J., Hashimoto, M., Kwon, A.H., Rwei, A., Shankarappa, S.A., Tsui, J.H. & Kohane, D.S. Synthetic ligand-coated magnetic nanoparticles for microfluidic bacterial separation from blood. Nano Lett., 14, 1-5.
Bacterial sepsis is a serious clinical condition that can lead to multiple organ dysfunction and death despite timely treatment with antibiotics and fluid resuscitation. We have developed an approach to clearing bacteria and endotoxin from the bloodstream, using magnetic nanoparticles (MNPs) modified with bis-Zn-DPA, a synthetic ligand that binds to both Gram-positive and Gram-negative bacteria. Magnetic microfluidic devices were used to remove MNPs bound to Escherichia coli , a Gram-negative bacterium commonly implicated in bacterial sepsis, from bovine whole blood at flows as high as 60 mL/h, resulting in almost 100% clearance. Such devices could be adapted to clear bacteria from septicemic patients.
2013 Mizrahi, B., Shankarappa, S.A., Hickey, J.M., Dohlman, J.C., Timko, B.P., Whitehead, K.A., Lee, J.J., Langer, R., Anderson, D.G. & Kohane, D.S. A Stiff Injectable Biodegradable Elastomer. Adv. Funct. Mater., 23, 1527-1533
Injectable materials often have shortcomings in mechanical and drug-eluting properties that are attributable to their high water contents. A water-free, liquid four-armed PEG modified with dopamine end groups is described which changed from liquid to elastic solid by reaction with a small volume of Fe3+ solution. The elastic modulus and degradation times increased with increasing Fe3+ concentrations. Both the free base and the water-soluble form of lidocaine could be dissolved in the PEG4-dopamine and released in a sustained manner from the cross-linked matrix. PEG4-dopamine was retained in the subcutaneous space in vivo for up to 3 weeks with minimal inflammation. This material's tailorable mechanical properties, biocompatibility, ability to incorporate hydrophilic and hydrophobic drugs and release them slowly are desirable traits for drug delivery and other biomedical applications.
2013 Mizrahi, B., Khoo, X., Chiang, H.H., Sher, K.J., Feldman, R.G., Lee, J.J., Irusta, S. & Kohane, D.S. Long-lasting antifouling coating from multi-armed polymer. Langmuir, 29, 10087-10094.
We describe a new antifouling surface coating, based on aggregation of a short amphiphilic four-armed PEG-dopamine polymer into particles and on surface binding by catechol chemistry. An unbroken and smooth polymeric coating layer with an average thickness of approximately 4 μm was formed on top of titanium oxide surfaces by a single step reaction. Coatings conferred excellent resistance to protein adhesion. Cell attachment was completely prevented for at least eight weeks, although the membranes themselves did not appear to be intrinsically cytotoxic. When linear PEG or four-armed PEG of higher molecular weight were used, the resulting coatings were inferior in thickness and in preventing protein adhesion. This coating method has potential applicability for biomedical devices susceptible to fouling after implantation.
2013 Lee, J.J., White, A.G., Rice, D.R. & Smith, B.D. In vivo imaging using polymeric nanoparticles stained with near-infrared chemiluminescent and fluorescent squaraine catenane endoperoxide. Chem. Commun., 49, 3016-3018.
Polystyrene nanoparticles stained with squaraine catenane endoperoxide exhibit remarkably high chemiluminescence and enable optical imaging of biodistribution in living mice. Whole-body chemiluminescence imaging was much more effective than fluorescence at identifying lung accumulation of the nanoparticles.
2012 Smith, B.A., O'Neil, E.J., Lampkins, A.J., Johnson, J.R., Lee, J.J., Cole, E.L. & Smith, B.D. Evaluation of fluorescent phosphatidylserine substrates for the aminophospholipid flippase in mammalian cells. J. Fluoresc., 22, 93-101.
A series of fluorescent phosphatidylserine and phosphatidylcholine derivatives were prepared and evaluated by cell microscopy for ability to translocate across mammalian plasma membranes via the putative aminophospholipid flippase. Phosphatidylserine derivatives, with either a neutral 7-nitrobenz-2-oxa-1,3-diazol-4-yl (NBD) or a coumarin fluorophore appended to the 2-acyl chain, entered the cytosol of all three cell lines tested and control experiments showed that the translocation was due to flippase activity. In contrast, a phosphatidylserine conjugate containing a charged and polar carboxyfluorescein was not translocated and remained in the cell plasma membrane. The phosphatidylserine-coumarin derivative exhibits bright fluorescence and higher photostability than the NBD analogues, and thus is a promising new fluorescent probe for extended-imaging studies of flippase action in living cells using laser confocal microscopes.
2011 Lee, J.J., Goncalves, A., Smith, B., Palumbo, R., White, A.G. & Smith, B.D. Singlet Oxygen Release and Cell Toxicity of a Chemiluminescent Squaraine Rotaxane Dye: Implications for Molecular Imaging. Aust. J. Chem., 64, 604-610.
The water soluble tetraguanidinium squaraine rotaxane 2 was prepared and photoconverted to its corresponding squaraine rotaxane endoperoxide (SREP), 2EP. As expected, 2EP undergoes a thermal cycloreversion reaction that releases 60 ± 4% singlet oxygen and produces near-infrared emission in aqueous solution. Cell toxicity assays in the dark, using human and bacterial cell cultures, showed that 2EP (up to 20 µM) is no more toxic than its parent 2. This suggests that SREP-derived imaging probes are not likely to exhibit a significant toxicity effect due to the slow release of stoichiometric amounts of singlet oxygen. Additional photosensitization experiments showed that tetraguanidinium squaraine rotaxane 2 is a weak photosensitizer, but nonetheless, red light irradiation of cell cultures that were pre-incubated with 2 (>3 µM) produced moderate phototoxicity. Fluorescence microscopy studies attribute the phototoxicity of 2 to its ability to penetrate into the cell cytosol. The implications of these results are discussed in the context of effective methods to activate SREP as chemiluminescent probes for in vivo optical molecular imaging.
2011 Lee, J.J., Baumes, J.M., Connell, R.D., Oliver, A.G. & Smith, B.D. Squaraine [2]catenanes: synthesis, structure and molecular dynamics. Chem. Commun., 47, 7188-7190.
Three squaraine [2]catenanes are synthesized and found to have bright, deep-red fluorescence and high chemical stability. The interlocked molecules undergo two large-amplitude dynamic processes, twisting of the squaraine macrocycle and skipping over the partner tetralactam.
2010 White, A.G., Fu, N., Leevy, W.M., Lee, J.J., Blasco, M.A. & Smith, B.D. Optical imaging of bacterial infection in living mice using deep-red fluorescent squaraine rotaxane probes. Bioconjug. Chem., 21, 1297-1304.
Two structurally related fluorescent imaging probes allow optical imaging of bacterial leg infection models in living athymic and immunocompetent mice. Structurally, the probes are comprised of a deep-red fluorescent squaraine rotaxane scaffold with two appended bis(zinc(II)-dicolylamine) (bis(Zn-DPA)) targeting ligands. The bis(Zn-DPA) ligands have high affinity for the anionic phospholipids and related biomolecules that reside within the bacterial envelope, and they are known to selectively target bacterial cells over the nearly uncharged membrane surfaces of healthy mammalian cells. Planar, whole-animal optical imaging studies showed that intravenous dosing of either probe (10 nmol) allowed imaging of localized infections of Gram-positive Staphylococcus aureus and Gram-negative Salmonella enterica serovar typhimurium. High selectivity for the infected target leg (T) over the contralateral nontarget leg (NT) was reflected by T/NT ratios up to six. The infection imaging signal was independent of mouse humoral immune status, and there was essentially no targeting at a site of sterile inflammation induced by injection of λ-carrageenan. Furthermore, the fluorescent probe imaging signal colocalized with the bioluminescence signal from a genetically engineered strain of S. enterica serovar typhimurium. Although not highly sensitive (the localized infection must contain at least ∼106 colony forming units for fluorescence visualization), the probes are remarkably selective for bacterial cells considering their low molecular weight (<1.5 kDa) and simple structural design. The more hydrophilic of the two probes produced a higher T/NT ratio in the early stages of the imaging experiment and washed out more rapidly from the blood clearance organs (liver, kidney). Therefore, it is best suited for longitudinal studies that require repeated dosing and imaging of the same animal. The results indicate that fluorescent probes based on squaraine rotaxanes should be broadly useful for in vivo animal imaging studies, and they further validate the ability of imaging probes with bis(Zn-DPA) ligands to selectively target bacterial infections in living animals.
2010 Lee, J.J., White, A.G., Baumes, J.M. & Smith, B.D. Microwave-assisted slipping synthesis of fluorescent squaraine rotaxane probe for bacterial imaging. Chem. Commun., 46, 1068-1069.
Microwave heating accelerates quantitative squaraine rotaxane formation by slipping and facilitates production of a bacterial imaging probe with zinc dipicolylamine targeting ligands.
2010 Gassensmith, J.J., Matthys, S., Lee, J.J., Wojcik, A., Kamat, P.V. & Smith, B.D. Squaraine rotaxane as a reversible optical chloride sensor. Eur. J. Chem., 16, 2916-2921.
A mechanically interlocked squaraine rotaxane is comprised of a deep-red fluorescent squaraine dye inside a tetralactam macrocycle. NMR studies show that Cl− binding to the rotaxane induces macrocycle translocation away from the central squaraine station, a process that is completely reversed when the Cl− is removed from the solution. Steady-state fluorescence and excited-state lifetime measurements show that this reversible machine-like motion modulates several technically useful optical properties, including a three-fold increase in deep-red fluorescence emission that is observable to the naked eye. The excited states were characterized quantitatively by time-correlated single photon counting, femtosecond transient absorption spectroscopy, and nanosecond laser flash photolysis. Cl− binding to the rotaxane increases the squaraine excited singlet state lifetime from 1.5 to 3.1 ns, and decreases the excited triplet state lifetime from >200 to 44 μs. Apparently, the surrounding macrocycle quenches the excited singlet state of the encapsulated squaraine dye and stabilizes the excited triplet state. Prototype dipsticks were prepared by adsorbing the lipophilic rotaxane onto the ends of narrow, C18-coated, reverse-phase silica gel plates. The fluorescence intensity of a dipstick increased eighteen-fold upon dipping in an aqueous solution of tetrabutylammonium chloride (300 mM) and was subsequently reversed by washing with pure water. It is possible to develop the dipsticks for colorimetric determination of Cl− levels by the naked eye. After dipping into aqueous tetrabutylammonium chloride, a dipstick’s color slowly fades at a rate that depends on the amount of Cl− in the aqueous solution. The fading process is due primarily to hydrolytic bleaching of the squaraine chromophore within the rotaxane. That is, association of Cl− to immobilized rotaxane induces macrocycle translocation and exposure of the electrophilic C4O2 core of the squaraine station, which is in turn attacked by the ambient moisture to produce a bleached product.
2010 Baumes, J.M., Gassensmith, J.J., Giblin, J., Lee, J.J., White, A.G., Culligan, W.J., Leevy, W.M., Kuno, M. & Smith, B.D. Storable, thermally activated, near-infrared chemiluminescent dyes and dye-stained microparticles for optical imaging. Nat. Chem., 2, 1025-1030.
Imaging techniques are a vital part of clinical diagnostics, biomedical research and nanotechnology. Optical molecular imaging makes use of relatively harmless, low-energy light and technically straightforward instrumentation. Self-illuminating, chemiluminescent systems are particularly attractive because they have inherently high signal contrast due to the lack of background emission. Currently, chemiluminescence imaging involves short-lived molecular species that are not stored but are instead generated in situ, and they typically emit visible light, which does not penetrate far through heterogeneous biological media. Here, we describe a new paradigm for optical molecular imaging using squaraine rotaxane endoperoxides, interlocked fluorescent and chemiluminescent dye molecules that have a squaraine chromophore encapsulated inside a macrocycle endoperoxide. Squaraine rotaxane endoperoxides can be stored indefinitely at temperatures below −20 °C, but upon warming to body temperature they undergo a unimolecular chemical reaction and emit near-infrared light that can pass through a living mouse.
2009 Lee, J.J. & Smith, B.D. Fluorescent chemosensor for reactive organohalides in micellar solution with an example of autocatalysis. Chem. Commun., 1962-1963 .
N-Alkylation of a fluorescent macrocyclic amine in aqueous micellar solution produces enhanced emission; the reaction with chloromethyl methyl ether exhibits autocatalysis.
2008 Lee, J.J., Noll, B.C. & Smith, B.D. Fluorescent chemosensor for chloroalkanes. Org. Lett., 10, 1735-1738.
Two structurally related macrocyclic amines with naphthalene groups are shown to act as fluorescent dosimeters for reactive chloroalkanes, including the common industrial solvent dichloromethane. The macrocyclic structures contain two NH residues which greatly accelerate N-alkylation by activating the chloride leaving group. The chemical reaction increases fluorescence intensity by promoting excimer emission and attenuating the quenching induced by photoinduced electron transfer (PET).
2008 Gassensmith, J.J., Lee, J.-J., Noll, B.C. & Smith, B.D. Crossing the threshold from accelerated substitution to elimination with a bifunctional macrocycle. New J. Chem., 32, 843-847.
A previously reported macrocyclic amine with anion binding amide residues can be N-alkylated at highly accelerated reaction rates to give quaternary ammonium products. This present study examines the reactivity with 1,2-disubstituted ethanes. Accelerated substitution is observed with 1,2-dichloroethane (5000 times faster than analogous control amines); whereas, accelerated elimination is the outcome with 3-halopropionitriles (10 000 times faster than analogous control amines). The structure of the protonated form of the macrocycle is analyzed by X-ray diffraction. The rates of elimination for 3-chloro, 3-bromoand 3-iodopropionitrile were measured and the relative order of second-order rate constants with triethylamine was 1 : 43 : 182 which reflects the expected order of leaving groupabilities. In the case of the macrocycle, the relative order of second-order rate constants was 1 : 29 : 61. The macrocyclic cavity preferentially stabilizes the charge developing on the smaller and more basic Cl− leaving group. The kinetic data are consistent with a bimolecular syn elimination mechanism.
2007 Stanger, K.J., Lee, J.J. & Smith, B.D. Dramatic acceleration of the Menschutkin reaction and distortion of halide leaving-group order. J. Org. Chem., 72, 9663-9668.
Compared to structurally related linear trialkylamines, a simple macrocyclic amine with an anion-binding cavity exhibits very large rate enhancements (>105) for stoichiometric N-alkylation with primary alkyl, allyl, and benzyl halides in the weakly polar solvent CDCl3. There is also a major distortion of the halide leaving-group order. For example, with benzyl halides the relative leaving-group order with a control amine is Cl (1) < Br (71) < I (160), whereas the leaving-group order with the macrocyclic amine is I (0.4) < Cl (1) < Br (8.5). Reaction with the macrocyclic amine is inhibited by the addition of DMSO, which is unusual because the Menschutkin reaction is normally enhanced by the presence of a polar aprotic solvent. Competitive inhibition studies indicate that the reaction proceeds through a prereaction complex. Effective molarities for the subsequent unimolecular N-alkylation step with 4-t-butylbenzyl halides are 4-t-BuBnCl (62 000 M) > 4-t-BuBnBr (2200 M) > 4-t-BuBnI (35 M); thus, the free energy of activation is selectively decreased for organohalides having smaller and more charge dense leaving groups. Likely reasons for this selective enhancement effect are: (a) increased transition-state stabilization due to hydrogen bonding in the macrocyclic pocket and (b) reduced entropic penalty in the transition state due to an increased fraction of prereaction complexes that are oriented in a near attack conformation. The study suggests that it should be possible to develop highly reactive macrocyclic amines that selectively sense or scavenge carcinogenic haloalkanes from the atmosphere.
2005 Lee, J.J., Stanger, K.J., Noll, B.C., Gonzalez, C., Marquez, M. & Smith, B.D. Rapid fixation of methylene chloride by a macrocyclic amine. J. Am. Chem. Soc., 127, 4184-4185.
A simple macrocyclic amine is alkylated by methylene chloride to give a quaternary ammonium chloride salt. When methylene chloride is the solvent, the reaction exhibits pseudo-first-order kinetics, and the reaction half-life at 25.0 °C is 2.0 min. The reaction half-life for a structurally related, acyclic amine is approximately 50 000 times longer. Detailed calculations favor a mechanism where the methylene chloride associates with the macrocycle to form an activated prereaction complex. The macrocyclic nitrogen subsequently attacks the methylene chloride with a classic SN2 trajectory, and although the carbon−chlorine bond breaks, the chloride leaving group does not separate from the newly formed cationic macrocycle, such that the product is a tightly associated ion-pair. X-ray crystal structures of the starting amine and the product salt, as well as kinetic data, support this mechanism.