Evaluating the oral delivery of GalNAc-conjugated siRNAs in rodents and non-human primates.

Oral delivery is the most widely used and convenient route of administration of medicine. However, oral administration of hydrophilic macromolecules is commonly limited by low intestinal permeability and pre-systemic degradation in the gastrointestinal (GI) tract. Overcoming some of these challenges allowed emergence of oral dosage forms of peptide-based drugs in clinical settings. Antisense oligonucleotides (ASOs) have also been investigated for oral administration but despite the recent progress, the bioavailability remains low. Given the advancement with highly potent and durable trivalent N-acetylgalactosamine (GalNAc)-conjugated small interfering RNAs (siRNAs) via subcutaneous (s.c.) injection, we explored their activities after oral administration. We report robust RNA interference (RNAi) activity of orally administrated GalNAc-siRNAs co-formulated with permeation enhancers (PEs) in rodents and non-human primates (NHPs). The relative bioavailability calculated from NHP liver exposure was <2.0% despite minimal enzymatic degradation in the GI. To investigate the impact of oligonucleotide size on oral delivery, highly specific GalNAc-conjugated single-stranded oligonucleotides known as REVERSIRs with different lengths were employed and their activities for reversal of RNAi effect were monitored. Our data suggests that intestinal permeability is highly influenced by the size of oligonucleotides. Further improvements in the potency of siRNA and PE could make oral delivery of GalNAc-siRNAs as a practical solution.

Single-Fraction Stereotactic Ablative Body Radiotherapy for Primary and Extracranial Oligometastatic Cancers.

Stereotactic ablative body radiotherapy (SABR) consists of delivering high doses of ionising radiation, typically across three to eight fractions with high precision and conformity. SABR has become increasingly commonplace throughout the last quarter of a century and is offered for the treatment of various primary and metastatic tumour types. Delivering SABR in a single fraction has arisen as an appealing possibility for several reasons. These include fewer hospital visits, greater patient convenience, improved sustainability and lower costs. However, these factors must be balanced against considerations such as toxicity, side-effects and, most importantly, progression-free and overall survival. In this review we seek to analyse the results of studies looking at the efficacy of single-fraction SABR for lung, prostate, renal and pancreas primary tumours, as well as oligometastases. The tumour type to be most widely treated with single-fraction SABR is lung, but its remit continues to expand. We also look at the biological rationale underpinning SABR and how this can be extended to single-fraction regimens. Finally, we turn our attention towards the future directions of SABR and specifically single-fraction regimens. These include the possibility of combining SABR with immunotherapy and technological advances in the field, which could serve to expand the scope of SABR. We conclude by summarising the current clinical studies of single-fraction SABR.

Modulation of carcinogenesis with selected GRAS nutraceuticals via Keap1-Nrf2 signaling pathway.

Keap1-Nrf2 is a fundamental signaling cascade known to promote or prevent carcinogenesis. Extensive studies identify the key target of modulatory aspects of Keap1-Nrf2 signaling against cancer. Nutraceuticals are those dietary agents with many health benefits that have immense potential for cancer chemoprevention. The nutritional supplements known as nutraceuticals are found to be one of the most promising chemoprevention agents. Upon investigating the dual nature of Nrf2, it became clear that, in addition to shielding normal cells from numerous stresses, Nrf2 may also promote the growth of tumors. In the present review, we performed a systematic analysis of the role of 12 different nutraceuticals like curcumin, sulforaphane, resveratrol, polyunsaturated fatty acids (PUFA) from fish oil, lycopene, soybean, kaempferol, allicin, thymoquinone, quercetin, gingerol, and piperine in modulating the Nrf2/Keap1 signaling mechanism. Among these, 12 Generally Recognized As Safe (GRAS) certified nutraceuticals, sulforaphane is the most extensively studied compound in modulating Keap1-Nrf signaling. Even though there is much evidence at preclinical levels, further high-quality research is still required to validate the potential role of these nutraceuticals in Keap1-Nrf2 modulation.

Impact of the COVID-19 Pandemic on Outcomes for Patients with Lung Cancer Receiving Curative-intent Radiotherapy in the UK.

AIMS: Previous work found that during the first wave of the COVID-19 pandemic, 34% of patients with lung cancer treated with curative-intent radiotherapy in the UK had a change to their centre's usual standard of care treatment (Banfill et al. Clin Oncol 2022;34:19-27). We present the impact of these changes on patient outcomes. MATERIALS AND METHODS: The COVID-RT Lung database was a prospective multicentre UK cohort study including patients with stage I-III lung cancer referred for and/or treated with radical radiotherapy between April and October 2020. Data were collected on patient demographics, radiotherapy and systemic treatments, toxicity, relapse and death. Multivariable Cox and logistic regression were used to assess the impact of having a change to radiotherapy on survival, distant relapse and grade ≥3 acute toxicity. The impact of omitting chemotherapy on survival and relapse was assessed using multivariable Cox regression. RESULTS: Patient and follow-up forms were available for 1280 patients. Seven hundred and sixty-five (59.8%) patients were aged over 70 years and 603 (47.1%) were female. The median follow-up was 213 days (119, 376). Patients with stage I-II non-small cell lung cancer (NSCLC) who had a change to their radiotherapy had no significant increase in distant relapse (P = 0.859) or death (P = 0.884); however, they did have increased odds of grade ≥3 acute toxicity (P = 0.0348). Patients with stage III NSCLC who had a change to their radiotherapy had no significant increase in distant relapse (P = 0.216) or death (P = 0.789); however, they did have increased odds of grade ≥3 acute toxicity (P < 0.001). Patients with stage III NSCLC who had their chemotherapy omitted had no significant increase in distant relapse (P = 0.0827) or death (P = 0.0661). CONCLUSION: This study suggests that changes to radiotherapy and chemotherapy made in response to the COVID-19 pandemic did not significantly affect distant relapse or survival. Changes to radiotherapy, namely increased hypofractionation, led to increased odds of grade ≥3 acute toxicity. These results are important, as hypofractionated treatments can help to reduce hospital attendances in the context of potential future emergency situations.

Metabolically Stable Anomeric Linkages Containing GalNAc-siRNA Conjugates: An Interplay among ASGPR, Glycosidase, and RISC Pathways.

Conjugation of synthetic triantennary N-acetyl-d-galactosamine (GalNAc) to small interfering RNA (siRNA) mediates binding to the asialoglycoprotein receptor (ASGPR) on the surface of hepatocytes, facilitating liver-specific uptake and siRNA-mediated gene silencing. The natural ß-glycosidic bond of the GalNAc ligand is rapidly cleaved by glycosidases in vivo. Novel GalNAc ligands with S-, and C-glycosides with both α- and ß-anomeric linkages, N-glycosides with ß-anomeric linkage, and the O-glycoside with α-anomeric linkage were synthesized and conjugated to siRNA either on-column during siRNA synthesis or through a high-throughput, post-synthetic method. Unlike natural GalNAc, modified ligands were resistant to glycosidase activity. The siRNAs conjugated to newly designed ligands had similar affinities for ASGPR and similar silencing activity in mice as the parent GalNAc-siRNA conjugate. These data suggest that other factors, such as protein-nucleic acid interactions and loading of the antisense strand into the RNA-induced silencing complex (RISC), are more critical to the duration of action than the stereochemistry and stability of the anomeric linkage between the GalNAc moiety of the ligand conjugated to the sense strand of the siRNA.

Comparative Evaluation of Fracture Resistance of Endodontically Treated Bicuspids Instrumented With Hand Files, TruNatomy, ProTaper Next, ProTaper Gold, and WaveOne - An In vitro Study.

Aim: The study aims to compare and evaluate the fracture resistance of endodontically treated bicuspids instrumented with Hand Files, TruNatomy (TRN), ProTaper Next (PTN), ProTaper Gold (PTG), and WaveOne (WO). Materials and Methods: In total, 45 extracted single-rooted human premolar teeth were selected and sectioned at or below the cementoenamel junction to obtain roots 15 mm long. The samples were divided into four experimental groups and one control group (n = 9): instrumentation with nickel-titanium (NiTi) Hand Files (control group), instrumentation with TRN files, instrumentation with PTN files, instrumentation with PTG files, and instrumentation with WO files. The samples were obturated by lateral compaction technique using gutta-percha points and AH Plus sealer. A vertical load was applied to the tooth using the universal testing machine (Tecsol-TSI-BDS-2Kn-Sr No. 170710) for the fracture resistance test. Statistical analysis was performed. Results: The study reported that teeth instrumented with NiTi hand files exhibited the highest fracture resistance when compared to all the rotary and reciprocating file systems. Among rotary and reciprocating instruments, root prepared with TRN files showed the most significant resistance to fracture compared with PTN, PTG, and WO files. Conclusion: Within the limitations of this study, it can be concluded that minimally invasive instrumentation of the system preserves more pericervical dentin, which may increase the resistance to fracture. Results of this study and other studies support the use of minimally tapered instruments to improve the fracture resistance of endodontically treated teeth.

Expanding RNAi therapeutics to extrahepatic tissues with lipophilic conjugates.

Therapeutics based on short interfering RNAs (siRNAs) delivered to hepatocytes have been approved, but new delivery solutions are needed to target additional organs. Here we show that conjugation of 2'-O-hexadecyl (C16) to siRNAs enables safe, potent and durable silencing in the central nervous system (CNS), eye and lung in rodents and non-human primates with broad cell type specificity. We show that intrathecally or intracerebroventricularly delivered C16-siRNAs were active across CNS regions and cell types, with sustained RNA interference (RNAi) activity for at least 3 months. Similarly, intravitreal administration to the eye or intranasal administration to the lung resulted in a potent and durable knockdown. The preclinical efficacy of an siRNA targeting the amyloid precursor protein was evaluated through intracerebroventricular dosing in a mouse model of Alzheimer's disease, resulting in amelioration of physiological and behavioral deficits. Altogether, C16 conjugation of siRNAs has the potential for safe therapeutic silencing of target genes outside the liver with infrequent dosing.

Comparative evaluation of shear bond strength of a bioactive material to composite resin using three different universal bonding agents: An in vitro study.

Background: Calcium silicate-based cements or bioceramics have revolutionized and simplified pulp-capping procedures due to its versatility and accessibility. Aim: This study aimed to assess the shear bond strength (SBS) of a bioceramic material to composite resin at two aging periods and with three universal adhesives. Materials and Methods: Forty-eight samples of Biodentine with a height of 2 mm and internal diameter of 4 mm were prepared. After 12 min of mixing, 24 samples were randomly selected and divided into four subgroups: Group I: Single Bond Universal, Group II: Palfique Universal Bond, Group III: G-Premio BOND, and Group IV: Control. Composite resin was restored over Biodentine after the application of universal adhesives using a cylindrical plastic mold of 2 mm height and 2 mm internal diameter. This process was repeated 24 h after mixing on the remaining 24 samples of Biodentine. The universal testing machine was used to measure the SBS of the fractured specimens, followed by stereomicroscopic evaluation. One-way ANOVA test and Bonferroni post hoc test were used to statistically analyze the data. Results: Highest SBS values were observed in Group III at 12 min and 24 h of the setting of Biodentine. Conclusions: Compared to the 12-min group, SBS was higher at 24 h. Group III exhibited higher bond strength than other subgroups.