ZhengLab (Page 12)

Conformational modulation of in vitro activity of cyclic RGD peptides via aziridine aldehyde-driven macrocyclization chemistry

Roxin A, Chen J, Scully CC, Rotstein BH, Yudin AK & Zheng G Bioconjugate Chemistry, 2012 Here, we demonstrate a conjugation strategy whereby cyclic RGD-containing macrocycles are prepared using aziridine aldehydes, isocyanides, and linear peptides, followed by conjugation to a cysteamine linker. Our method involves site-selective aziridine ring-opening with theContinue Reading

Enzymatic regioselection for the synthesis and biodegradation of porphysome nanovesicles

Lovell JF, Jin CS, Huynh E, MacDonald TD, Cao W & Zheng G Angewandte Chemie International Edition, 2012 A select few: An enzyme screen is used to identify two enzymes that selectively cleave porphyrin–lipid regioisomers (see picture). Either of the isomerically pure conjugates assembles into physically similar porphysome nanovesicles. AlthoughContinue Reading

Mechanistic insights into LDL nanoparticle-mediated siRNA delivery

Jin H, Lovell JF, Chen J, Lin Q, Ding L, Ng K, Pandey R, Manoharan M, Zhang Z & Zheng G Bioconjugate Chemistry, 2011 Although small interfering RNA (siRNA) can silence the expression of disease-related genes, delivery of these highly charged molecules is challenging. Delivery approaches for siRNAs are activelyContinue Reading

In vivo detection of phospholipase C by enzyme-activated near-infrared probes

Mawn TM, Popov AV, Beardsley NJ, Milkevitch M, Stefflova K, Zheng G & Delikatny EJ Bioconjugate Chemistry, 2011 In this article, the characterization of the first near-infrared (NIR) phospholipase-activated molecular beacon is reported, and its utility for in vivo cancer imaging is demonstrated. The probe consists of three elements: aContinue Reading

Porphyrin FRET acceptors for apoptosis induction and monitoring

Lovell JF, Chan MW, Qi Q, Chen J & Zheng G Journal of the American Chemical Society, 2011 Photodynamic therapy (PDT) stands to benefit from improved approaches to real-time treatment monitoring. One method is to use activatable photosensitizers that can both induce cell death (via singlet oxygen) and monitor itContinue Reading

Liposomal nanostructures for photosensitizer delivery

Jin CS & Zheng G Lasers in Surgery and Medicine, 2011 Background and Objective: In photodynamic therapy (PDT), photosensitizers are activated by light of a specific wavelength and produce cytotoxic molecules to damage diseased tissues. Most photosensitizers are hydrophobic and easily aggregate in aqueous solution. To maintain their photodynamic activityContinue Reading

Porphyrin-crosslinked-hydrogel for fluorescence-guided monitoring and surgical resection

Lovell JF, Roxin A, Ng KK, Qi Q, McMullen JD, DaCosta RS & Zheng G Biomacromolecules, 2011 We demonstrate that porphyrins can be used as efficient cross-linkers to generate a new class of hydrogels with enabling optical properties. Tetracarboxylic acid porphyrins reacted with PEG diamines to form a condensation polyamideContinue Reading

Attenuation of nontargeted cell-kill using a high-density lipoprotein-mimicking peptide-phospholipid nanoscaffold

Yang M, Chen J, Cao W, Ding L, Ng KK, Jin H, Zhang Z & Zheng G Nanomedicine, 2011 Research in the development of nanoscale drug carriers primarily focuses on maximizing drug delivery efficiency to tumor tissues. However, less attention has been given to minimizing drug toxicity to non-targeted cellsContinue Reading

Imaging of specific activation of photodynamic molecular beacons in breast cancer vertebral metastases

Liu TW, Akens MK, Chen J, Wise-Milestone L, Wilson BC & Zheng G Bioconjugate Chemistry, 2011 Breast cancer is the second leading cause of cancer-related death in women. Approximately 85% of patients with advanced cases will develop spinal metastases. The vertebral column is the most common site of breast cancerContinue Reading

Lipoprotein-inspired nanoparticles for cancer theranostics

Ng KK, Lovell JF & Zheng G Accounts of Chemical Research, 2011 Over hundreds of millions of years, animals have evolved endogenous lipoprotein nanoparticles for shuttling hydrophobic molecules to different parts of the body. In the last 70 years, scientists have developed an understanding of lipoprotein function, often in relationshipContinue Reading