Ionizable Lipids from Click Reactions for Lipid Nanoparticle Assembling and mRNA Delivery.

Ionizable lipid-containing lipid nanoparticles (LNPs) are regarded as promising nonviral vectors for gene therapy delivery systems. Rationale design of the ionizable lipid structure based on initial screening of ionizable lipid molecule libraries combined with systematic comparison and analysis on the physical chemical parameters related to delivery efficiency greatly accelerated the discovery of novel LNP candidates for delivering various nucleic acid therapeutics like mRNAs (mRNAs). Based on the copper-catalyzed azide-alkyne click reaction, which is highly efficient and biocompatible, we were able to obtain the lipid molecule library containing a common triazole moiety between different lipid tails and various substituents as hydrophilic head groups. Herein, we systematically investigated the change of pKa values of different ionizable lipid molecules with different substituents as head groups in the click-based lipid library, mapping the pKa value change to different steps in the process of the LNP assembly and mRNA delivery. Systematic analyses on the data including the pKa value of the ionized lipids and the encapsulation and delivery efficiency of mRNA in LNPs with these ionized lipids provided the possibility of rational design on the head and tail structure for the triazole containing ionized lipids to realize highly efficient delivery of different mRNAs.

An AIE-based monofunctional Pt(ii) complex for photodynamic therapy through synergism of necroptosis-ferroptosis.

Side effects and drug resistance are among the major problems of platinum-based anticancer chemotherapies. Photodynamic therapy could show improved tumor targeting ability and better anticancer effect by region-selective light irradiation. Here, we report an aggregation-induced emission (AIE)-based monofunctional Pt(ii) complex (TTC-Pt), which shows enhanced singlet oxygen production by introduction of a Pt atom to elevate the intersystem crossing (ISC) rate. Moreover, TTC-Pt exhibits decent capacity of inhibition on tumor cell growth upon light irradiation, with negligible dark toxicity compared to the commonly used chemodrug cisplatin. Mechanistic study suggests that TTC-Pt enters HeLa cells via the endocytosis pathway and locates mainly in lysosomes, causing FSP1 down-regulation and intracellular lipid peroxidation accumulation under irradiation, finally leading to ferroptosis and necroptosis. The synergistic dual cell death pathways could help to kill apoptosis-resistant tumor cells. Therefore, TTC-Pt could serve as a potent antitumor photosensitizer, which overcomes the drug resistance with minimum side effects.

Golgi apparatus-targeted aggregation-induced emission luminogens for effective cancer photodynamic therapy.

Golgi apparatus (GA) oxidative stress induced by in situ reactive oxygen species (ROS) could severely damage the morphology and function of GA, which may open up an avenue for effective photodynamic therapy (PDT). However, due to the lack of effective design strategy, photosensitizers (PSs) with specific GA targeting ability are in high demand and yet quite challenging. Herein, we report an aggregation-induced emission luminogen (AIEgen) based PS (TPE-PyT-CPS) that can effectively target the GA via caveolin/raft mediated endocytosis with a Pearson correlation coefficient up to 0.98. Additionally, the introduction of pyrene into TPE-PyT-CPS can reduce the energy gap between the lowest singlet state (S1) and the lowest triplet state (T1) (ΔEST) and exhibits enhanced singlet oxygen generation capability. GA fragmentation and cleavage of GA proteins (p115/GM130) are observed upon light irradiation. Meanwhile, the apoptotic pathway is activated through a crosstalk between GA oxidative stress and mitochondria in HeLa cells. More importantly, GA targeting TPE-T-CPS show better PDT effect than its non-GA-targeting counterpart TPE-PyT-PS, even though they possess very close ROS generation rate. This work provides a strategy for the development of PSs with specific GA targeting ability, which is of great importance for precise and effective PDT.

Simultaneous Zn2+ tracking in multiple organelles using super-resolution morphology-correlated organelle identification in living cells.

Zn2+ plays important roles in metabolism and signaling regulation. Subcellular Zn2+ compartmentalization is essential for organelle functions and cell biology, but there is currently no method to determine Zn2+ signaling relationships among more than two different organelles with one probe. Here, we report simultaneous Zn2+ tracking in multiple organelles (Zn-STIMO), a method that uses structured illumination microscopy (SIM) and a single Zn2+ fluorescent probe, allowing super-resolution morphology-correlated organelle identification in living cells. To guarantee SIM imaging quality for organelle identification, we develop a new turn-on Zn2+ fluorescent probe, NapBu-BPEA, by regulating the lipophilicity of naphthalimide-derived Zn2+ probes to make it accumulate in multiple organelles except the nucleus. Zn-STIMO with this probe shows that CCCP-induced mitophagy in HeLa cells is associated with labile Zn2+ enhancement. Therefore, direct organelle identification supported by SIM imaging makes Zn-STIMO a reliable method to determine labile Zn2+ dynamics in various organelles with one probe. Finally, SIM imaging of pluripotent stem cell-derived organoids with NapBu-BPEA demonstrates the potential of super-resolution morphology-correlated organelle identification to track biospecies and events in specific organelles within organoids.

Bimetallic Photoredox Catalysis: Visible Light-Promoted Aerobic Hydroxylation of Arylboronic Acids with a Dirhodium(II) Catalyst.

We report the use of a rhodium(II) dimer in visible light photoredox catalysis for the aerobic oxidation of arylboronic acids to phenols under mild conditions. Spectroscopic and computational studies indicate that the catalyst Rh2(bpy)2(OAc)4 (1) undergoes metal-metal to ligand charge transfer upon visible light irradiation, which is responsible for catalytic activity. Further reactivity studies demonstrate that 1 is a general photoredox catalyst for diverse oxidation reactions.

Functional genetic polymorphisms in CYP2C19 gene in relation to cardiac side effects and treatment dose in a methadone maintenance cohort.

Abstract Methadone maintenance therapy is an established treatment for heroin dependence. This study tested the influence of functional genetic polymorphisms in CYP2C19 gene encoding a CYP450 enzyme that contributes to methadone metabolism on treatment dose, plasma concentration, and side effects of methadone. Two single nucleotide polymorphisms (SNPs), rs4986893 (exon 4) and rs4244285 (exon 5), were selected and genotyped in 366 patients receiving methadone maintenance therapy in Taiwan. The steady-state plasma concentrations of both methadone and its EDDP metabolite enantiomers were measured. SNP rs4244285 allele was significantly associated with the corrected QT interval (QTc) change in the electrocardiogram (p=0.021), and the Treatment Emergent Symptom Scale (TESS) total score (p=0.021) in patients who continued using heroin, as demonstrated with a positive urine opiate test. Using the gene dose (GD) models where the CYP2C19 SNPs were clustered into poor (0 GD) versus intermediate (1 GD) and extensive (2 GD) metabolizers, we found that the extensive metabolizers required a higher dose of methadone (p=0.035), and showed a lower plasma R-methadone/methadone dose ratio (p=0.007) in urine opiate test negative patients, as well as a greater QTc change (p=0.008) and higher total scores of TESS (p=0.018) in urine opiate test positive patients, than poor metabolizers. These results in a large study sample from Taiwan suggest that the gene dose of CYP2C19 may potentially serve as an indicator for the plasma R-methadone/methadone dose ratio and cardiac side effect in patients receiving methadone maintenance therapy. Further studies of pharmacogenetic variation in methadone pharmacokinetics and pharmacodynamics are warranted in different world populations.

UGT2B7 genetic polymorphisms are associated with the withdrawal symptoms in methadone maintenance patients.

AIM: To test whether the genetic polymorphisms within the gene encoding the UGT2B7 gene may have an impact on methadone treatment. MATERIALS & METHODS: Twelve SNPs in UGT2B7 were selected. 366 methadone maintenance treatment patients in Taiwan were recruited and genotyped. RESULTS: In a genotype recessive model, rs6600879, rs6600880, rs4554144, rs11940316, rs7438135, rs7662029, rs7668258, rs7439366, rs4292394 and rs6600893 showed significant associations with severity of withdrawal symptoms (permutation p < 0.002), pupil size (permutation p < 0.048) and tremor (permutation p < 0.008). Haplotypes of GATCAGCCGC and CTCTGATTCT were significantly associated with pupil size score and tremor score (p < 0.034). CONCLUSION: These results suggest that SNPs of the UGT2B7 gene may play important roles in opiate withdrawal symptoms.

Genetic polymorphisms in the opioid receptor mu1 gene are associated with changes in libido and insomnia in methadone maintenance patients.

Methadone, a synthetic racemic opioid that primarily works as a µ-opioid receptor (OPRM1) agonist, is commonly used for the treatment of heroin addiction. Genetic association studies have reported that the OPRM1 gene is involved in the physiology of heroin and alcohol addiction. Our current study is designed to test the hypothesis that genetic polymorphisms in the OPRM1 gene region are associated with methadone dosage, plasma concentrations, treatment responses, adverse reactions and withdrawal symptoms in a methadone maintenance treatment (MMT) cohort from Taiwan. Fifteen OPRM1 single nucleotide polymorphisms (SNPs) were selected and genotyped using DNA samples from 366 MMT patients. The plasma concentrations of methadone and its metabolite were measured by high performance liquid chromatography. The results obtained using dominant model analysis indicate that the OPRM1 SNPs rs1074287, rs6912029, rs12209447, rs510769, rs3798676, rs7748401, rs495491, rs10457090, rs589046, rs3778152, rs563649, and rs2075572 are significantly associated with change-in-libido side effects (adjusted p<0.042). Using recessive model analysis, these SNPs were also found to be significantly associated with insomnia side effects in this cohort (p<0.009). The significance of the insomnia findings was mainly contributed by a subgroup of patients who had a positive urine morphine test (p<0.022), and by individuals who did not use benzodiazepine hypnotics (p<0.034). Our current data thus suggest that genetic polymorphisms in OPRM1 may influence the change-in-libido and insomnia side effects sometimes found in MMT patients.

Genetic polymorphisms in CYP3A4 are associated with withdrawal symptoms and adverse reactions in methadone maintenance patients.

AIM: Methadone maintenance therapy is one of the standard treatments for heroin addiction. The isozyme CYP3A4 of the CYP system is one of the metabolic enzymes, as well as CYP2B6, responsible for the metabolism of methadone. The aim of the present study is to evaluate the potential use of genetic polymorphisms in CYP3A4 as biomarkers for the prediction of methadone treatment responses. MATERIALS & METHODS: A total of 366 Han Chinese methadone maintenance treatment patients in Taiwan were recruited in this study. Main clinical assessments included the clinical opioid withdrawal scale (COWS), the treatment emergent symptom scale (TESS) and the plasma concentrations of methadone and its metabolites. Genetic associations of six SNPs in the CYP3A4 gene were calculated using a general linear model. RESULTS: Genotypes and allele types of rs4646440 and rs2242480 were found to be significantly associated with the severity of withdrawal symptoms rated by COWS (p = 0.012, 0.0096, 0.017 and 0.012, respectively) as well as the side effects rated by TESS (p = 0.0089, 0.028, 0.0027 and 0.0085, respectively). The allele types associated with more severe withdrawal symptoms are also associated with more severe side effects and less betel nut (Areca catechu) use (p = 0.009 for rs4646440, p = 0.0063 for rs2242480). Further analyses on specific withdrawal symptoms in COWS showed that the genetic variants in rs4646440 are significantly associated with heart rate (allele type p = 0.0019). CONCLUSION: These results suggested that genetic variants in the CYP3A4 gene may be useful indicators for the severity of side effects and withdrawal symptoms for methadone treatment.

CYP2B6 polymorphisms influence the plasma concentration and clearance of the methadone S-enantiomer.

Methadone is a racemic compound composed of the R-form and S-form enantiomers. The drug is usually used in maintenance therapy for the heroin-addicted patients. In our previous study, we found that the cytochrome P-450 (CYP) isozyme 2B6 preferentially metabolizes the S-methadone enantiomer. We thus tested whether CYP2B6 gene polymorphisms had any influence on the concentration or clearance of methadone. Ten single nucleotide polymorphisms within this gene region were evaluated in 366 patients undergoing methadone maintenance for at least 3 months. The plasma steady-state levels of racemic methadone and its metabolite 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine were then measured in these individuals. The rs10403955 (T allele in intron 1), rs3745274 (G allele in exon 4), rs2279345 (T allele in intron 5), and rs707265 (A allele in exon 9) CYP2B6 allele types were found to be significantly associated with a higher clearance, a lower plasma concentration, and a lower concentration-to-dosage (C/D) ratio of (S)-methadone (P < 0.0017). Two haplotype blocks of a trinucleotide haplotype (rs8100458-rs10500282-rs10403955 in intron 1) and a hexanucleotide haplotype (rs2279342-rs3745274-rs2279343-rs2279345-rs1038376-rs707265 from intron 2 to exon 9) were constructed within CYP2B6. The major combinations of T-T-T and A-G-A-T-A-A of these particular haplotypes showed significant associations with the plasma concentrations of S-methadone and its C/D ratio (P < 0.0001, respectively). We conclude that genetic polymorphisms in the CYP2B6 gene may therefore be indicators of the clearance, plasma concentration and C/D ratio of S-methadone.