The analysis of HPV integration sites based on nanopore sequencing and the profiling changes along the course of photodynamic therapy.

OBJECTIVE: To detect the HPV genotype and integration sites in patients with high-risk HPV infection at different stages of photodynamic therapy using nanopore technology and to evaluate the treatment effect. METHODS: Four patients with HPV infection were selected and subjected to photodynamic therapy, and cervical exfoliated cell was sampled at before treatment, after three courses of treatment and six courses of treatment, their viral abundance and insertion sites were analyzed by nanopore technology, and pathological examinations were performed before and after treatment. In this study, we developed a novel assay that combined viral sequence enrichment and Nanopore sequencing for identification of HPV genotype and integration sites at once. The assay has obvious advantages over qPCR or NGS-based methods, as it has better sensitivity after viral sequences enrichment and can generate long-reads (kb to Mb) for better detection rate of structure variations, moreover, fast turn-around time for real-time viral sequencing and analysis. RESULTS: The pathological grade was reduced in all four patients after photodynamic therapy. Virus has been cleared in two cases after treatment, the virus amount reduced after treatment but not completely cleared in one case, and two type viruses were cleared and one type virus persisted after treatment in the last patient with multiple infection. Viral abundance and the number of integration sites were positively correlated. Gene enrichment analysis showed complete viral clearance in 1 patient and 3 patients required follow-up. CONCLUSION: Nanopore sequencing can effectively monitor the abundance of HPV viruses and integration sites to show the presence status of viruses, and combined with the results of gene enrichment analysis, the treatment effect can be dynamically assessed.

Clinical Efficacy and Safety of AdV-tk Gene Therapy for Patients with Cervical Squamous Intraepithelial Lesion: A Prospective Study.

Cervical cancer is the fourth most common type of cancer for women in 2020, and many more women have cervical precancerous lesion-squamous intraepithelial lesion (SIL). Early treatment of cervical SIL to reverse or delay its progression is an important approach to reduce the incidence of cervical cancer. The efficacy and safety of adenovirus-based vectors expressing the thymidine kinase gene (AdV-tk) in the treatment of multiple types of cancers shows promise for its use in gynecology. We aim to provide relevant clinical efficacy and safety data after introducing AdV-tk for the treatment of cervical SIL for the first time through this prospective study. We conducted a maximum of 6 sessions to administer AdV-tk gene therapy to 23 patients (mean age: 35 years old) with cervical low-/high-grade SIL (LSIL/HSIL) who were enrolled from August 2015 to April 2018 and analyzed the clinical characteristics and follow-up outcomes (mean follow-up period: 7.3 months). The present study consisted of 17 patients (73.9%) with cervical HSIL and 6 patients with LSIL confirmed by colposcopy-directed biopsy. We observed an overall histological remission and regression rate of 87.0% (20/23, 95% confidence interval [95% CI]: 73.2-100, p < 0.001) after AdV-tk gene therapy. Eight patients (34.8%) were detected with human papillomavirus (HPV) 16/18 subtypes and 13 patients were found to be positive with at least one of the other 13 high-risk HPV (HR-HPV) subtypes, while 2 patients did not have any of the 15 HR-HPV subtypes. The overall clearance rate of HR-HPV was 76.2% (16/21, 95% CI: 58.0-94.4, p = 0.016) after AdV-tk gene therapy. For safety evaluation, no severe complications were reported in any of the 23 patients. The most commonly reported symptom was fever in 52.2% (12/23) of patients and all symptoms were fully resolved after symptomatic treatment. Our data indicate that AdV-tk gene therapy has high efficacy and safety in the treatment of cervical SIL among gynecological patients. Our findings provide clinical evidence on the potential promotion and application of AdV-tk in the treatment of cervical SIL, and potentially for cervical cancer, among gynecological patients.

Synthesis of Ultrahigh Molecular Weight Poly(methyl Methacrylate) via the Polymerization of MMA Initiated by the Combination of Palladium Carboxylates with Thiols.

A novel synthesis of ultrahigh molecular weight poly(methyl methacrylate) (PMMA) using organosulfur compounds combined with a catalytical amount of transition metal carboxylates as an initiator has been developed. The combination of 1-octanethiol with palladium trifluoroacetate (Pd(CF3COO)2) was found to be a very efficient initiator for the polymerization of methyl methacrylate (MMA). An ultrahigh molecular weight PMMA with a number-average molecular weight of 1.68 × 106 Da and a weight-average molecular weight of 5.38 × 106 Da has been synthesized at the optimal formulation of [MMA]:[Pd(CF3COO)2]:[1-octanethiol] = 94,300:8:23 at 70 °C. A kinetic study showed that the reaction orders with respect to Pd(CF3COO)2, 1-octanethiol, and MMA are 0.64, 1.26, and 1.46, respectively. A variety of techniques such as proton nuclear magnetic resonance spectroscopy (1H NMR), electrospray ionization mass spectroscopy (ESI-MS), size exclusion chromatography (SEC), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and electron paramagnetic resonance spectroscopy (EPR) were employed to characterize the produced PMMA and palladium nanoparticles (Pd NPs). The results revealed that Pd(CF3COO)2 was firstly reduced by the excess of 1-octanethiol to form Pd NPs at the early stage of the polymerization, followed by the adsorption of 1-octanethiol on the surface of nanoparticles and subsequent generation of corresponding thiyl radicals to initiate the polymerization of MMA.

Curc-mPEG454, a PEGylated curcumin derivative, as a multi-target anti-fibrotic prodrug.

Our previous studies demonstrated that Curc-mPEG454, a curcumin derivative modified with short-chain polyethylene glycol (PEG), not only increased the blood concentration of curcumin, but also retained its anti-inflammatory activity. Here, we aimed to evaluate the anti-fibrotic effect of Curc-mPEG454 on a rat liver fibrosis model induced by carbon tetrachloride (CCl4), and to explore the underlying mechanisms by integrating our total liver RNA sequencing (RNA-seq) data with recent liver single-cell sequencing (scRNA-seq) studies. 50 mg/kg and 100 mg/kg Curc-mPEG454 treatment significantly reduced the elevation of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) induced by CCl4, and the incidence of liver cirrhosis decreased from 75% to 37% and 35%, respectively. RNA-seq analysis revealed that Curc-mPEG454 significantly upregulated aldehyde oxidase 1 (AOX1) while downregulated cytochrome p450 26A1 (CYP26A1) and cytochrome p450 26B1 (CYP26B1) resulting in restoring liver retinoic acid (RA) level, increased glutamate-cysteine ligase catalytic subunit (GCLC) and glutamate-cysteine ligase modifier subunit (GCLM) expression to synthesize hepatic glutathione (GSH), and inhibited liver inflammation via down-regulating the Prostaglandin E Synthase 2 (PTGES2)/prostacyclin E2 (PGE2) signaling. Integrating scRNA-seq data revealed that Curc-mPEG454 effectively inhibited the expansion of scar-associated macrophage subpopulation and scar-producing myofibroblasts in the damaged liver, and remodeled the fibrotic niche via regulation of ligand-receptor interactions including platelet-derived growth factor-B (PDGF-B)/platelet-derived growth factor receptor-α (PDGFR-α) signaling. As a multi-target prodrug, PEGylated curcumin deserves further attention and research.

Schistosoma japonicum cystatin suppresses osteoclastogenesis via manipulating the NF­κB signaling pathway.

Abnormal osteoclastic activation and secretion of cysteine proteinases result in excessive bone resorption, which is one of the primary factors in the development of bone metabolic disorders, such as rheumatoid arthritis and osteoporosis. Mammalian cystatins have been demonstrated to restrain osteoclastic bone resorption and to alleviate severe osteolytic destruction via blocking the activity of cysteine proteinases. However, the specific effects of parasite cystatins on the formation and function of osteoclasts remain unclear. The purpose of the current study was to explore the effects of cystatins from Schistosoma japonicum (Sj­Cys) on macrophage colony­stimulating factor (M­CSF) and receptor activator of NF­κB ligand (RANKL)­induced osteoclast differentiation, as well as the underlying molecular mechanisms. Recombinant Sj­Cys (rSj­Cys) dose­dependently restrained osteoclast formation, with a half­maximal inhibitory concentration (IC50) value of 0.3 µM, and suppressed osteoclastic bone resorptive capability in vitro. The findings were based on tartrate resistant acid phosphatase (TRAP) staining and bone resorption assays, respectively. However, the cell viability assay showed that the repression of rSj­Cys on osteoclast formation did not depend on effects on cell viability or apoptosis. Based on the results of reverse transcription­quantitative PCR and western blot analysis, it was found that rSj­Cys downregulated the expression levels of osteoclastogenesis­related genes and proteins, by interfering with M­CSF and RANKL­induced NF­κB signaling and downstream transcription factors during early­phase osteoclastogenesis. Overall, the results of the present study revealed that rSj­Cys exerted an inhibitory role in osteoclast differentiation and could be a prospective biotherapeutic candidate for the treatment and prevention of bone metabolic disorders.

Facile Synthesis of Ultrahigh Molecular Weight Poly(Methyl Methacrylate) by Organic Halides in the Presence of Palladium Nanoparticles.

A facile and versatile approach for the synthesis of ultrahigh molecular weight poly(methyl methacrylate) (PMMA) at mild conditions was developed. Certain organic halides combined with a catalytical amount of palladium nanoparticles (Pd NPs) were found to be very effective in initiating polymerizations of methyl methacrylate (MMA), methyl acrylate, vinyl acetate and other vinyl monomers. An ultrahigh molecular weight PMMA with a number-average molecular weight of 4.65 × 106 Da and a weight-average molecular weight of 8.08 × 106 Da was synthesized at 70 °C using 2-bromoisobutyric acid ethyl ester (EBiB) as an initiator in the presence of catalytical amount (10.1 ppm) of Pd NPs. A kinetic investigation found that the orders of polymerization with respect to EBiB, Pd NP and MMA were 0.23, 0.50, and 0.58, respectively. Proton nuclear magnetic resonance (1H NMR) combined with matrix-assisted laser desorption ionization time of flight mass spectroscopy (MALDI-TOF) and gel permeation chromatography (GPC) were used to prove that the macromolecular chain had an end-group of EBiB residue. The electron spin resonance (ESR), transmission electron microscope (TEM), and X-ray photoelectron spectroscopy (XPS) results reveal that the reaction of EBiB with Pd NPs caused a bromo atom (Br) transfer from EBiB to Pd NPs and resulted in the generation of EBiB residue radical to initiate the polymerization of MMA and the formation of PdIIBr2 on the surface of Pd nanoparticles.

Development of Environmentally Friendly Atom Transfer Radical Polymerization.

Atom transfer radical polymerization (ATRP) is one of the most successful techniques for the preparation of well-defined polymers with controllable molecular weights, narrow molecular weight distributions, specific macromolecular architectures, and precisely designed functionalities. ATRP usually involves transition-metal complex as catalyst. As the most commonly used copper complex catalyst is usually biologically toxic and environmentally unsafe, considerable interest has been focused on iron complex, enzyme, and metal-free catalysts owing to their low toxicity, inexpensive cost, commercial availability and environmental friendliness. This review aims to provide a comprehensive understanding of iron catalyst used in normal, reverse, AGET, ICAR, GAMA, and SARA ATRP, enzyme as well as metal-free catalyst mediated ATRP in the point of view of catalytic activity, initiation efficiency, and polymerization controllability. The principle of ATRP and the development of iron ligand are briefly discussed. The recent development of enzyme-mediated ATRP, the latest research progress on metal-free ATRP, and the application of metal-free ATRP in interdisciplinary areas are highlighted in sections. The prospects and challenges of these three ATRP techniques are also described in the review.

Porcine Prediction of Pharmacokinetic Parameters in People: A Pig in a Poke?

The minipig has become an animal of considerable interest in preclinical drug development. It has been used in toxicology research and in examining/establishing regulatory guidelines as a nonrodent animal model. We have reviewed some basic issues that one would want to consider in the development and testing of any animal model for humans. The pig is a reasonable alternative to the dog, but there are some clear limitations and unexplained disparities in the literature, which require further study; primary among these is the need for standardization in choice of breed and sex and routine protocols. The minipig offers numerous advantages over other established animal models, and it has similarities to the human with regard to anatomy, physiology, and biochemistry. The gastrointestinal tract is structurally and functionally similar to humans. This appears to be true for enzymes and transporters in the gut as well, but more study is needed. One major concern is assessment of oral drug absorption, especially with regard to potential food effects due to gastric emptying differences, yet this does not appear to be a consistent observation. Hepatic metabolism seems to reflect enzymatic patterns in humans, with some differences. Kidney function seems similar to humans but requires further study. We have analyzed literature data that suggest the pig would offer a reasonable model for human oral bioavailability and for allometric predictions of clearance. The minipig appears to be the model for dermal absorption in humans, and we discuss this in terms of literature data and our own in-house experience.

Discovery of MK-8282 as a Potent G-Protein-Coupled Receptor 119 Agonist for the Treatment of Type 2 Diabetes.

The ever-growing prevalence of type 2 diabetes in the world has necessitated an urgent need for multiple orally effective agents that can regulate glucose homeostasis with a concurrent reduction in body weight. G-Protein coupled receptor 119 (GPR119) is a GPCR target at which agonists have demonstrated glucose-dependent insulin secretion and shows beneficial effects on glycemic control. Herein, we describe our efforts leading to the identification of a potent, oral GPR-119 agonist, MK-8282, which shows improved glucose tolerance in multiple animal models and has excellent off-target profile. The key design elements in the compounds involved a combination of a fluoro-pyrimidine and a conformationally constrained bridged piperidine to impart good potency and efficacy.

Curc-mPEG454, a PEGylated Curcumin Derivative, Improves Anti-inflammatory and Antioxidant Activities: a Comparative Study.

We previously demonstrated that a PEGylated curcumin (Curc-mPEG454) significantly inhibited cyclooxygenase 2 (COX-2) expression and improved the progression of liver fibrosis. The current study systematically evaluates its anti-inflammatory and antioxidant activities in vitro in a comparative study with curcumin, aspirin, NS-398, and vitamin C. RAW264.7 murine macrophages were pretreated with Curc-mPEG454, curcumin, aspirin, NS-398, or vitamin C at the indicated concentration for 2 h; then, the cells were stimulated with 1 µg/mL lipopolysaccharide (LPS) for 24 h. The levels of pro-inflammatory cytokines and mediators, including IL-6, TNF-α, PGE2, NO, and GSH, and the activities of COX-2, SOD, and CAT, and the transcription factors involved in inflammation, such as NF-κB, c-Jun, and Nrf2, were measured. Curc-mPEG454 showed lower cytotoxicity (IC50 57.8 µM) when compared with that of curcumin (IC50 32.6 µM) and inhibited the release of the inflammatory cytokines IL-6, TNF-α, IL-1ß, and MCP-1 in a concentration-dependent manner. At 16 µM, Curc-mPEG454 was most potent in the suppression of COX-2 expression at a transcriptional level rather than in the suppression of the catalytic activity of COX-2. Like curcumin, Curc-mPEG454 significantly reduced intracellular ROS production and enhanced the activities of SOD and CAT and the level of GSH to protect cells from LPS-induced oxidative injury. Further, its anti-inflammatory and antioxidation mechanisms are related to inhibition of NF-κB p65 nuclear translocation and c-Jun phosphorylation and to activation of Nrf2. Taken together, these findings indicate that PEGylation of curcumin not only improves its biological properties but also interferes with multiple targets involved in the inflammatory response. Curc-mPEG454 is a powerful and beneficial anti-inflammatory and antioxidant agent that merits further investigation. Graphical Abstract ᅟ.

PEGylated Curcumin Derivative Attenuates Hepatic Steatosis via CREB/PPAR-γ/CD36 Pathway.

Curcumin has the potential to cure dyslipidemia and nonalcoholic fatty liver disease (NAFLD). However, its therapeutic effects are curbed by poor bioavailability. Our previous work has shown that modification of curcumin with polyethylene glycol (PEG) improves blood concentration and tissue distribution. This study sought to investigate the role of a novel PEGylated curcumin derivative (Curc-mPEG454) in regulating hepatic lipid metabolism and to elucidate the underlying molecular mechanism in a high-fat-diet- (HFD-) fed C57BL/6J mouse model. Mice were fed either a control chow diet (D12450B), an HFD (D12492) as the NAFLD model, or an HFD with Curc-mPEG454 administered by intraperitoneal injection at 50 mg/kg or 100 mg/kg for 16 weeks. We found that Curc-mPEG454 significantly lowered the body weight and serum triglyceride (TG) levels and reduced liver lipid accumulation in HFD-induced NAFLD mice. It was also shown that Curc-mPEG454 suppressed the HFD-induced upregulated expression of CD36 and hepatic peroxisome proliferator activated receptor-γ (PPAR-γ), a positive regulator of CD36. Moreover, Curc-mPEG454 dramatically activated cAMP response element-binding (CREB) protein, which negatively controls hepatic PPAR-γ expression. These findings suggest that Curc-mPEG454 reverses HFD-induced hepatic steatosis via the activation of CREB inhibition of the hepatic PPAR-γ/CD36 pathway, which may be an effective therapeutic for high-fat-diet-induced NAFLD.

Discovery of the oxazabicyclo[3.3.1]nonane derivatives as potent and orally active GPR119 agonists.

The design and synthesis of two conformationally restricted oxazabicyclo octane derivatives as GRP119 agonists is described. Derivatives of scaffold C, with syn configuration, have the best overall profiles with respect to solubility and in vivo efficacy. Compound 25a was found to have extremely potent agonistic activity and was orally active in lowering blood glucose levels in a mouse oral glucose tolerance test at a dose of 0.1 mg/kg.

Discovery of novel spiro 1,3,4-thiadiazolines as potent, orally bioavailable and brain penetrant KSP inhibitors.

Kinesin spindle protein (KSP) is a mitotic kinesin that is expressed only in proliferating cells and plays a key role in spindle pole separation, formation of a bipolar mitotic spindle, as well as centrosome separation and maturation. Inhibition of KSP has the potential to provide anti-tumor activity while avoiding peripheral neuropathy associated with some microtubule-targeted drugs. Based on MK-0731 and related heterocyclic compounds targeting the KSP monastrol binding site, structurally constrained spiro-cyclic KSP inhibitors were designed. In particular, rapid evaluation and optimization of the novel spiro 1,3,4-thiadiazolines resulted in a series of potent KSP inhibitors demonstrating mechanism based activities in cells, including induction of the mitotic marker phospho-histone H3 and induction of monaster spindle formation. Further optimization of the pharmacokinetic (PK) properties afforded MK-8267 as a potent, orally bioavailable and brain penetrant KSP inhibitor which showed anti-tumor activity in preclinical xenograft models.

Reproductive effects of a pegylated curcumin.

Curcumin, a polyphenol derived from the rhizome turmeric, has potential as an anticancer agent. We synthesized an amphipathic/surfactant pegylated curcumin (curcumin-PEG) designed for parenteral administration. Objectives of these investigations were to assess side-effects of a therapeutic regimen of curcumin-PEG in a preclinical model. Intraperitoneal (ip) tumor burdens were reduced in athymic female mice grafted with human SKOV-3 ovarian adenocarcinoma cells and injected intravenously (iv) with curcumin-PEG. There were no gross anatomical or histopathological effects detected in non-reproductive organs. Uteri (luminal fluid imbibition) and ovaries (decreased folliculogenesis) were affected by treatment. Curcumin-PEG ip hastened the onset of puberty in immature female mice. Live births were reduced in mature females housed with males and treated iv with curcumin-PEG; mating (vaginal plugs) was not affected. Accessory gland weights, testicular testosterone concentrations, and spermatogenesis were diminished in mature male mice following iv curcumin-PEG. Estrogenic/antiandrogenic and pregnancy-disrupting effects of a water soluble/bioavailable curcumin were demonstrated.

Controversies in allometric scaling for predicting human drug clearance: an historical problem and reflections on what works and what does not.

This review focuses on a discussion of the controversies in allometric scaling (AS) for predicting human clearance from a mathematical and statistical perspective. First, a history of allometric scaling in comparative biology and its use in pharmacokinetics are reviewed. It is shown that the application of AS in predicting human clearance values based on a limited number of animal species (typically, 3 or 4) contains fundamental statistical errors when AS was first introduced from comparative biology. Second, the mathematical nature of various allometrically-based methods is revealed and the soundness of these methods is assessed. It is demonstrated that any of these methods, which incorporate a correction factor in a traditional allometric approach (varying-exponent allometry), not only reduces the statistical power of the allometric analysis, but are also incorrect with regard to aspects of biology. Finally, it is concluded that allometry remains a valuable tool for predicting human clearance, and should be applied in the context of a fixed exponent. However, fixed-exponent allometry does not provide satisfactory accuracy in predicting human clearance, since it is not able to capture the biological differences among species. Therefore, it is recommended that the overall effort in predicting human pharmacokinetics should be directed to the collection and generation of reliable data (both in vitro and in vivo) along with a better understanding of the DMPK properties of the chemical entity.

Controversy in the allometric application of fixed- versus varying-exponent models: a statistical and mathematical perspective.

This commentary is a reply to a recent article by Mahmood commenting on the authors' article on the use of fixed-exponent allometry in predicting human clearance. The commentary discusses eight issues that are related to criticisms made in Mahmood's article and examines the controversies (fixed-exponent vs. varying-exponent allometry) from the perspective of statistics and mathematics. The key conclusion is that any allometric method, which is to establish a power function based on a limited number of animal species and to extrapolate the resulting power function to human values (varying-exponent allometry), is infused with fundamental statistical errors.

SCH 2047069, a novel oral kinesin spindle protein inhibitor, shows single-agent antitumor activity and enhances the efficacy of chemotherapeutics.

Kinesin spindle protein (KSP) is a mitotic kinesin required for the formation of the bipolar mitotic spindle, and inhibition of this motor protein results in mitotic arrest and cell death. KSP inhibitors show preclinical antitumor activity and are currently undergoing testing in clinical trials. These agents have been dosed intravenously using various dosing schedules. We sought to identify a KSP inhibitor that could be delivered orally and thus provide convenience of dosing as well as the ability to achieve more continuous exposure via the use of dose-dense administration. We discovered SCH 2047069, a potent KSP inhibitor with oral bioavailability across species and the ability to cross the blood-brain barrier. The compound induces mitotic arrest characterized by a monaster spindle and is associated with an increase in histone H3 and mitotic protein monoclonal 2 phosphorylation both in vitro and in vivo. SCH 2047069 showed antitumor activity in a variety of preclinical models as a single agent and in combination with paclitaxel, gemcitabine, or vincristine.

Amphiphilic curcumin conjugate-forming nanoparticles as anticancer prodrug and drug carriers: in vitro and in vivo effects.

Curcumin has been shown to have high cytotoxicity towards various cancer cell lines, but its water insolubility and instability make its bioavailability exceedingly low and, thus, it is generally inactive in in vivo anticancer tests. Here, we report an intracellular-labile amphiphilic surfactant-like curcumin prodrug--curcumin conjugated with two short oligo(ethylene glycol) (Curc-OEG) chains via beta-thioester bonds that are labile in the presence of intracellular glutathione and esterase. Curc-OEG formed stable nanoparticles in aqueous conditions and served two roles--as an anticancer prodrug and a drug carrier. As an anticancer prodrug, the formed nanoparticles had a high and fixed curcumin-loading content of 25.3 wt%, and released active curcumin in the intracellular environment. Curc-OEG had high inhibition ability to several cancer cell lines due to apoptosis. Intravenously injected Curc-OEG significantly reduced the tumor weights and tumor numbers in the athymic mice xenografted with intraperitoneal SKOV-3 tumors and subcutaneous (mammary fat pad) MDA-MB-468 tumors. Preliminary systemic toxicity studies found that Curc-OEG did not cause acute and subchronic toxicities to mouse visceral organs at high doses. As drug carriers, Curc-OEG nanoparticles could carry other anticancer drugs, such as doxorubicin and camptothecin, and ship them into drug-resistant cells, greatly enhancing the cytotoxicity of the loaded drug. Thus, Curc-OEG is a promising prototype that merits further study for cancer therapy.

Curcumin polymers as anticancer conjugates.

Curcumin has been shown highly cytotoxic towards various cancer cell lines, but its water-insolubility and instability make its bioavailability exceedingly low and thus it generally demonstrates low anticancer activity in in vivo tests. Herein, we report a novel type of polymer-drug conjugates--the high molecular weight curcumin polymers (polycurcumins) made by condensation polymerization of curcumin. The polycurcumins as backbone-type conjugates have advantages of high drug loading efficiency, fixed drug loading contents, stabilized curcumin in their backbones, and tailored water-solubility. The polycurcumins may have many potential applications and their antitumor activities are investigated in this work. The polycurcumins are cytotoxic to cancer cells, but a polyacetal-based polycurcumin (PCurc 8) is highly cytotoxic to SKOV-3, OVCAR-3 ovarian cancers, and MCF-7 breast cancer cell lines. It can be quickly taken up by cancer cells into their lysosomes, where PCurc 8 hydrolyzes and releases active curcumin. It arrests SKOV-3 cell cycle at G(0)/G(1) phase in vitro and induces cell apoptosis partially through the caspase-3 dependent pathway. In vivo, intravenously (i.v.) injected PCurc 8 shows remarkable antitumor activity in SKOV-3 intraperitoneal (i.p.) xenograft tumor model.

Facile synthesis of polyester dendrimers from sequential click coupling of asymmetrical monomers.

Polyester dendrimers are attractive for in vivo delivery of bioactive molecules due to their biodegradability, but their synthesis generally requires multistep reactions with intensive purifications. A highly efficient approach to the synthesis of dendrimers by simply "sticking" generation by generation together is achieved by combining kinetic or mechanistic chemoselectivity with click reactions between the monomers. In each generation, the targeted molecules are the major reaction product as detected by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). The only separation needed is to remove the little unreacted monomer by simple precipitation or washing. This simple clicklike process without complicated purification is particularly suitable for the synthesis of custom-made polyester dendrimers.