Preclinical Assessment of the PI3Kα Selective Inhibitor Inavolisib and Prediction of Its Pharmacokinetics and Efficacious Dose in Human.

1. Small molecule inhibitors of the PI3K pathway have been extensively investigated as potential anticancer agents. Among the effectors in this pathway, PI3Kα is the kinase most frequently associated with the development of tumors, through mutations and amplifications of the PIK3CA gene encoding the p110α catalytic subunit.2. Inavolisib (GDC-0077) is a potent and PI3Kα-selective inhibitor that also specifically triggers the degradation of the mutant p110α protein.3. We characterized inavolisib ADME properties in preclinical in vitro and in vivo studies, assessed its efficacy in the PIK3CA mutant KPL-4 breast cancer xenograft model, and predicted its pharmacokinetics and efficacious dose in humans.4. Inavolisib had a moderate permeability (1.9•10-6 cm/s) in MDCK cells and was a P-gp and Bcrp1 substrate. It appeared metabolically stable in hepatocytes incubations from human and preclinical species. The systemic clearance was low in mouse, monkey and dog and high in rat. Oral bioavailability ranged from 57.5% to 100%. Inavolisib was efficacious in the KPL-4 sub-cutaneous xenograft model.5. The PK/PD model parameters estimated from the efficacy study, combined with PBPK model-predicted human PK profiles, projected that a dose of 3 mg could lead to clinical response. Inavolisib is currently being tested in phase 3 trials.

Thieno[3,2-b]thiophene for the Construction of Far-Red Molecular Rotor Hemicyanines as High-Affinity DNA Aptamer Fluorogenic Reporters.

The construction of far-red fluorescent molecular rotors (FMRs) is an imperative task for developing nucleic acid stains that have superior compatibility with cellular systems and complex matrices. A typical strategy relies on the methine extension of asymmetric cyanines, which unfortunately fails to produce sensitive rotor character. To break free from this paradigm, we have synthesized far-red hemicyanines using a dimethylamino thieno[3,2-b]thiophene donor. The resultant probes, designated as ATh2Ind and ATh2Btz, possess excitation maxima (λmax) of >600 nm and have been rigorously characterized by NMR, electrochemistry, and computational methods. The dyes possess alternating charge patterns like indodicarbocyanine (Cy5), but with twisted intramolecular charge transfer (TICT) rotational barriers at 60°, akin to the classical FMR thiazole orange (TO1). ATh2Btz also displays cyanine characteristics, enhancing its response upon binding to nucleic acids and allowing for efficient staining of cellular nuclei. When binding to the DNA aptamer for quinine (MN4), ATh2Btz exhibits a Kd of 17 nM, a 660-fold light-up response, brightness (Φfl x εmax) of ∼37,000 M-1cm-1, and λex/λem of 655/677 nm. The resulting far-red DNA-based MN4-ATh2Btz platform has been termed "pomegranate."

Characterizing patient experiences with repeat artificial urinary sphincter revisions through quantitative surveys and qualitative patient interviews.

Background: Artificial urinary sphincter (AUS) placement remains the gold-standard treatment for post-prostatectomy urinary incontinence (PPUI), despite their need for periodic surgical revision. Objective: To understand the experiences of patients who undergo repeat AUS revisions. Design: Mixed design including quantitative surveys and qualitative interviews for thematic analysis. Methods: Men with ⩾2 revisions were collected from a single-institution, retrospective database of AUS patients. Participants were interviewed about their prostatectomy, incontinence, AUS placement, and revisions. A survey was administered utilizing validated tools (e.g., Decision Regret Scale (DRS), Incontinence Impact Questionnaire-7) for quantitative analysis. Interview transcripts were used for qualitative thematic analysis. Results: Of 26 respondents, 20 completed the interview. Twenty-three men completed the survey. The mean DRS score for prostatectomy was 24 (standard deviation (SD) = 27), indicating low regret. Median Incontinence Impact Questionnaire score was 54 (SD = 27), with 70% of participants describing their PPUI as "severe." Participants experienced a significant decrease in daily pad usage with AUS placement (5.5 pre-AUS vs 1.4 post-AUS, p < 0.0001). Qualitative analysis revealed themes involving prostatectomy urgency, physician-patient relationships, expectation setting, and quality of follow-up. Most participants (96%) were satisfied with their initial AUS placement and endorsed a positive relationship with their urologist. However, 22% of participants were unaware of device limitations, including the need for revision. Some participants (26%) were uncertain of the status of their AUS, while some participants (35%) desired improved follow-up. Conclusions: Initial improvement and positive experiences with urologists motivate patients to undergo AUS repeat revision. Urologists should emphasize the limitations of the AUS before placement and follow up with patients to evaluate their needs for future care.

Neoadjuvant and Adjuvant Therapy in Resectable Pancreatic Adenocarcinoma.

While pancreatic adenocarcinoma requires surgical resection definitive cure, treatment paradigms are shifting toward a neoadjuvant approach to systemic therapy. Rationale is twofold: micro-metastatic disease is likely present in a majority of patients, reinforcing the importance of systemic therapy regardless of resectability; moreover, systemic therapy is well-tolerated and improves surgical outcomes when delivered preoperatively. Second, a neoadjuvant approach allows for selection of biology and patients most likely to benefit from potentially morbid surgery. This review examines the increasing body of evidence in support of empiric neoadjuvant therapy in pancreatic adenocarcinoma.

Automated cell lineage reconstruction using label-free 4D microscopy.

Patterns of lineal descent play a critical role in the development of metazoan embryos. In eutelic organisms that generate a fixed number of somatic cells, invariance in the topology of their cell lineage provides a powerful opportunity to interrogate developmental events with empirical repeatability across individuals. Studies of embryonic development using the nematode Caenorhabditis elegans have been drivers of discovery. These studies have depended heavily on high-throughput lineage tracing enabled by 4D fluorescence microscopy and robust computer vision pipelines. For a range of applications, computer-aided yet manual lineage tracing using 4D label-free microscopy remains an essential tool. Deep learning approaches to cell detection and tracking in fluorescence microscopy have advanced significantly in recent years, yet solutions for automating cell detection and tracking in 3D label-free imaging of dense tissues and embryos remain inaccessible. Here, we describe embGAN, a deep learning pipeline that addresses the challenge of automated cell detection and tracking in label-free 3D time-lapse imaging. embGAN requires no manual data annotation for training, learns robust detections that exhibits a high degree of scale invariance, and generalizes well to images acquired in multiple labs on multiple instruments. We characterize embGAN's performance using lineage tracing in the C. elegans embryo as a benchmark. embGAN achieves near-state-of-the-art performance in cell detection and tracking, enabling high-throughput studies of cell lineage without the need for fluorescent reporters or transgenics.

"One a penny, two a penny", I saw the hot cross bun sign".

The hot cross bun sign is a radiological sign seen on MRI due to pontocerebellar demyelination and loss of neurons along with preservation of the pontine tegmentum and corticospinal tracts which is classically seen in Multiple System Atrophy (MSA). Hot cross buns have been in existence since as early as the 14th century up until the point when Schrag et al. (1998) coupled the appearance of this age-old bread with the T2 imaging characteristics of MSA. Over time the radiological sign has expanded with a differential diagnosis of spinocerebellar ataxia, progressive multifocal leukoencephalopathy, paraneoplastic cerebellar degeneration, and variant Creutzfeldt-Jakob disease.

Burn Injury Results in Myeloid Priming during Emergency Hematopoiesis.

INTRODUCTION: Hematopoiesis proceeds in a tiered pattern of differentiation, beginning with hematopoietic stem cells (HSC) and culminating in erythroid, myeloid, and lymphoid lineages. Pathologically altered lineage commitment can result in inadequate leukocyte production or dysfunctional cell lines. Drivers of emergency hematopoiesis after burn injury are inadequately defined. Burn injury induces a myeloid predominance associated with infection that worsens outcomes. This study aims to further profile bone marrow HSCs following burn injury in a murine model. METHODS: C57BL/6 mice received burn or sham injury with ~12% total body surface area (TBSA) scald burn on the dorsal surface with subsequent sacrifice at 1, 2, 3, 7 and 10 days post-injury. Bone marrow (BM) from hindlimbs were analyzed for HSC populations via flow cytometry and analyzed using FlowJo Software (version 10.6). Event counts and frequencies were analyzed with multiple unpaired t-tests and linear mixed-effect regression. RT-PCR performed on isolated lineage negative BM cell RNA targeted PU.1, GATA-1, and GATA-3 with subsequent analysis conducted with QuantStudio 3 software. Statistical analysis and representation were performed on GraphPad software (Prism). RESULTS: Flow cytometry revealed significantly elevated proportions of Long-Term HSCs at 3 days post-injury (p < .05) and Short-Term HSCs at days 2, 3, and 10 (all p < .05) in burn-injured mice. There was a sustained, but not significant, increase in proportions in the multi-potent progenitor (MPP) 2 and 3 subpopulations in the burn cohort compared to sham controls. The common myeloid progenitor (CMP) proportion was significantly higher on days 3 and 10 (both p < .01), while the granulocyte-macrophage progenitor (GMP) proportion increased on days 1, 2, and 10 (p < .05, p < .01, p < .01). Although the megakaryocyte-erythrocyte progenitor (MEP) proportion appeared consistently lower in the burn cohort, this did not reach significance. mRNA analysis resulted in a downregulation of PU.1 on day 1 (p = 0.0002) with an upregulation by day 7 (p < 0.01). GATA-1 downregulation occurred by day 7 (p < 0.05), and GATA3 showed downregulation on days 3 and 7 (p < 0.05). DISCUSSION: Full-thickness burn results in an emergency hematopoiesis via proportional increase of Long Term-HSC and Short Term-HSC/MPP1 subpopulations beginning in the early post-injury period. Subsequent lineage commitment displays a myeloid predominance with a shift toward myeloid progenitors with mRNA analysis corroborating this finding with associated upregulation of PU.1 and downregulation of GATA-1 and GATA-3. Further studies are needed to understand how burn-induced emergency hematopoiesis may predispose to infection by pathologic lineage selection.

Avoid the Peel: Citrus Fruit Bezoar Causing Intestinal Perforation.

We report a highly unusual case of small bowel obstruction in an 86-year-old man from ingestion of a citrus fruit, known as kumquats, which led to intestinal perforation and peritonitis. He initially presented with a one-day history of diffuse abdominal pain associated with nausea and feculent emesis after eating whole pieces of unpeeled kumquats. When symptoms of peritonitis evolved with a blood lactate of 5.1 mg/dL, he was urgently taken to the operating room for exploration. Multiple areas with fibrous exudates and full-thickness ulceration were encountered along the distal jejunum and proximal ileum, with a partially obstructing intraluminal mass in the distal ileum. Treatment involved resection of 70 cm of non-viable bowel, removal of the intraluminal mass, and surgical re-establishment of intestinal continuity. Unpeeled kumquats were confirmed to have caused these intestinal findings. The patient did well following the operation and has had no further problems referred to by this management.

Testing novel strategies for patients hospitalised with HIV-associated disseminated tuberculosis (NewStrat-TB): protocol for a randomised controlled trial.

BACKGROUND: HIV-associated tuberculosis (TB) contributes disproportionately to global tuberculosis mortality. Patients hospitalised at the time of the diagnosis of HIV-associated disseminated TB are typically severely ill and have a high mortality risk despite initiation of tuberculosis treatment. The objective of the study is to assess the safety and efficacy of both intensified TB treatment (high dose rifampicin plus levofloxacin) and immunomodulation with corticosteroids as interventions to reduce early mortality in hospitalised patients with HIV-associated disseminated TB. METHODS: This is a phase III randomised controlled superiority trial, evaluating two interventions in a 2 × 2 factorial design: (1) high dose rifampicin (35 mg/kg/day) plus levofloxacin added to standard TB treatment for the first 14 days versus standard tuberculosis treatment and (2) adjunctive corticosteroids (prednisone 1.5 mg/kg/day) versus identical placebo for the first 14 days of TB treatment. The study population is HIV-positive patients diagnosed with disseminated TB (defined as being positive by at least one of the following assays: urine Alere LAM, urine Xpert MTB/RIF Ultra or blood Xpert MTB/RIF Ultra) during a hospital admission. The primary endpoint is all-cause mortality at 12 weeks comparing, first, patients receiving intensified TB treatment to standard of care and, second, patients receiving corticosteroids to those receiving placebo. Analysis of the primary endpoint will be by intention to treat. Secondary endpoints include all-cause mortality at 2 and 24 weeks. Safety and tolerability endpoints include hepatoxicity evaluations and corticosteroid-related adverse events. DISCUSSION: Disseminated TB is characterised by a high mycobacterial load and patients are often critically ill at presentation, with features of sepsis, which carries a high mortality risk. Interventions that reduce this high mycobacterial load or modulate associated immune activation could potentially reduce mortality. If found to be safe and effective, the interventions being evaluated in this trial could be easily implemented in clinical practice. TRIAL REGISTRATION: ClinicalTrials.gov NCT04951986. Registered on 7 July 2021 https://clinicaltrials.gov/study/NCT04951986.

Posterior-only 2-level vertebrectomy and fusion in a medically complex patient with lumbar metastasis: illustrative case.

BACKGROUND: Spinal metastases are commonly seen in patients with cancer and often indicate a poor prognosis. Treatment can include curative or palliative surgery, chemotherapy, and radiation therapy. The surgical approach varies widely on the basis of the affected region of the spine, the location of the tumor (anterior versus posterior), the goal of surgery, the health of the patient, and surgeon preference. OBSERVATIONS: The authors present a case of a 68-year-old male with intractable lower-back pain and substantially diminished ambulation. Diagnostic imaging revealed a lumbar metastasis from a cholangiocarcinoma primary at L2-3 (4.5 cm anteroposterior × 5.7 cm transverse × 7.0 cm craniocaudal). The patient underwent a 2-level vertebrectomy with expandable cage placement and T10 to S2 fusion via a posterior-only approach. The patient regained much of his mobility and quality of life after the surgery. LESSONS: Although this was a high-risk surgery, the authors show that a posterior-only approach can be used for lumbar vertebrectomies and fusion when necessary. Palliative surgeries carrying a high risk, especially in the setting of a limited prognosis, should include multidisciplinary deliberations and a thorough discussion of the risks and outcome expectations with the patient.

Evaluation of Patient-Centric Sample Collection Technologies for Pharmacokinetic Assessment of Large and Small Molecules.

Low-volume sampling devices offer the promise of lower discomfort and greater convenience for patients, potentially reducing patient burden and enabling decentralized clinical trials. In this study, we determined whether low-volume sampling devices produce pharmacokinetic (PK) data comparable to conventional venipuncture for a diverse set of monoclonal antibodies (mAbs) and small molecules. We adopted an open-label, non-randomized, parallel-group, single-site study design, with four cohorts of 10 healthy subjects per arm. The study drugs, doses, and routes of administration included: crenezumab (15 mg/kg, intravenous infusion), etrolizumab (210 mg, subcutaneous), GDC-X (oral), and hydroxychloroquine (HCQ, 200 mg, oral). Samples were collected after administration of a single dose of each drug using conventional venipuncture and three low-volume capillary devices: TassoOne Plus for liquid blood, Tasso-M20 for dry blood, both applied to the arm, and Neoteryx Mitra® for dry blood obtained from fingertips. Serum/plasma concentrations from venipuncture and TassoOne Plus samples overlapped and PK parameters were comparable for all drugs, except HCQ. After applying a baseline hematocrit value, the dry blood concentrations and PK parameters for the two monoclonal antibodies were comparable to those obtained from venipuncture. For the two small molecules, two bridging strategies were evaluated for converting dry blood concentrations to equivalent plasma concentrations. A baseline hematocrit correction and/or linear regression-based correction was effective for GDC-X, but not for HCQ. Additionally, the study evaluated the bioanalytical data quality and comparability from the various collection methods, as well as patient preference for the devices.

An Analysis of Orientation and Preceptorship Influence on Nurse Job Satisfaction Across Two States.

A large public nursing data set was used to determine whether orientation and/or preceptor programs impact job satisfaction among registered nurses in Maine and Massachusetts. There was no association between orientation and preceptor programs and satisfaction, nor evidence that new nurse status modified the relationship. There is a need for evaluation of orientation and preceptor programs' structure and effectiveness, and innovation is needed in promoting job satisfaction, thereby increasing nurse retention.

Characteristics of Maine and Massachusetts nurses interested in advanced nursing degrees.

BACKGROUND: Maine (ME) and Massachusetts (MA) nursing programs aim to develop collaborative training programs, but need to identify which nurses have interest in such programs. PURPOSE: We sought to determine sociodemographics of nurses seeking advanced nursing degrees nationally, and in ME and MA using the 2018 publicly available, National Sample Survey of Registered Nurses (NSSRN). METHODS: Weighted multivariable logistic regression for advanced degree-seeking, adjusted for sociodemographics. RESULTS: Of the n = 47,274 nurses (weighted n [Wn] = 3,608,633), 90.7 % were female, 74.1 % were white, and 15.8 % sought an advanced nursing degree on average 12.7 (SD 0.2) years after their first. Females vs. males had lower odds (OR 0.63, 95%CI [0.44-0.90]) and Black vs. White race had higher odds (OR 1.30, 95%CI [1.05-1.60]) of seeking doctorates. In Maine (Wn = 20,389), age 24-29 had higher odds (OR 2.98 (95%CI [1.06-3.74]), but in Massachusetts (Wn = 101,984), age 30+ had lower odds (OR 0.32, 95%CI [0.13-0.78]) of degree-seeking vs. <24 years. Initial nursing degrees earned between 1980 and 1989 had higher odds (OR 1.99, 95%CI [1.06-3.74]) in Maine, but between 2010 and 2014 had lower odds (OR 0.32, 95%CI [0.14-0.72]) in Massachusetts of degree-seeking, vs. before 1980. CONCLUSIONS: Targets for advanced nursing training programs may vary by state and sociodemographic profile.

Automated Cell Lineage Reconstruction using Label-Free 4D Microscopy.

Here we describe embGAN, a deep learning pipeline that addresses the challenge of automated cell detection and tracking in label-free 3D time lapse imaging. embGAN requires no manual data annotation for training, learns robust detections that exhibits a high degree of scale invariance and generalizes well to images acquired in multiple labs on multiple instruments.

Unlocking Pb2+ Sensing Potential in a DNA G-Quadruplex via Loop Modification with Fluorescent Chalcone Surrogates.

The ability of guanine (G)-rich DNA to bind toxic lead (Pb2+) ions within a G-quadruplex (GQ) motif is a leading DNA biosensor strategy. A major analytical hurdle for GQ detection of Pb2+ is competitive GQ templating by potassium (K+) ions. We employ the on-strand DNA synthesis of internal fluorescent chalcone surrogates within the 15-mer thrombin binding aptamer (TBA15) to address this challenge. Replacement of thymidine at the 3-position (T3) within TBA15 with an indole-4-hydroxy-indanone (Ind4HI) chalcone strongly decreases K+-GQ stability while enhancing Pb2+-GQ stability to increase Pb2+ binding specificity. The new T3-Ind4HI probe exhibits a 15-fold increase in fluorescence intensity upon binding of Pb2+ by the modified TBA15 and can detect 6.4 nM Pb2+ in the presence of 10 mM K+. Thus, replacement of the T3 residue of TBA15 with the new Ind4HI probe modulates metal ion affinity by native TBA15 to solve the analytical challenge posed by K+ in real water samples for detecting Pb2+ to meet regulatory guidelines by using a GQ biosensor.

Association Between Hypercholesterolemia and Lumbar Degenerative Back Pain: A Medicare Expenditure Panel Survey (MEPS) Study.

Introduction Hypercholesterolemia is known to be a major contributor to the morbidity associated with cardiovascular disease and has been hypothesized to result in degenerative changes to the spine through atherosclerosis of segmental lumbar vessels. The purpose of this study is to determine the relationship between hypercholesterolemia and degenerative lumbar spine conditions in a U.S. cohort. Methods A total of 30,461 participated in the 2018 Medicare Expenditure Panel Survey (MEPS). Of those, 1,063 subjects responded to whether a diagnosis of lumbar disorders with low back pain was present. Odds ratios (OR) were calculated, and logistic regression analyses were adjusted for demographic, education, occupation, cardiovascular and mental health conditions. Results Of the 1,063 respondents, 455 (43%) reported back pain. Mean age of the respondents was 62.7±16.1. Men and women reported back pain at similar rates (43% vs 45%, p=0.664). Age, race, education level and occupation were similar between those with and without back pain (p>0.05). Those with a diagnosis of depression had higher odds of having back pain (p<0.05). Prevalence of back pain in subjects who responded to the back pain diagnosis item on the survey was 42.6%. On univariate analysis, diagnosis of total cholesterol levels was significantly higher in those with a diagnosis of back pain (OR 1.36, 95% CI [1.20-1.54], p<.0001). Multivariable analysis showed that hypercholesterolemia was independently associated with back pain (adjusted OR 1.32, 95% CI [1.04-1.68], p=0.021) after controlling for covariates. Conclusions In this study, subjects with hypercholesterolemia were 34% more likely to have back pain after controlling for confounders which presents as a recent discovery amongst U.S. populations. Further studies should be performed to investigate the management of hypercholesterolemia in the development and progression of degenerative lumbar back pain.

Visual Outcomes of a Second-Generation, Enhanced UV Protected Light Adjustable Lens in Cataract Patients with Previous LASIK and/or PRK.

Purpose: To report on the visual outcomes of the second-generation (ActivShieldTM) Light Adjustable Lens (LAL) used in cataract surgery for patients with a history of laser refractive surgery (LASIK and/or photorefractive keratectomy [PRK]) using a co-managed, open-access methodology. Patients and Methods: This retrospective case series of consecutive patients with history of laser refractive surgery implanted with the second-generation LAL with an emmetropic target were included in the study. Following surgery, all patients received their ultraviolet (UV) light treatments at a separate open-access facility through a co-managed arrangement. Uncorrected distance visual acuity (UDVA), spherical equivalent (SE), and residual cylinder for eyes with an emmetropic refractive target were the primary outcome measures as documented at the patient's final, stable, refractive postoperative exam. Results: Thirty-three patients (34 eyes) with a history of laser refractive surgery were included in the study and implanted with the second-generation LAL with a postoperative emmetropic refractive target. Twenty-eight (82.4%) saw 20/20 or better and 9 (26.5%) saw 20/15 or better. The mean SE was 0.01 ± 0.31 D and 33 (97.1%) were within ±0.50 D SE of plano. The mean residual cylinder was -0.28 ± 0.32 D and 30 (88.2%) were within ±0.50 D. Conclusion: Use of the second-generation LAL was efficacious in cataract surgical patients with a history of LASIK and/or PRK using a co-managed, open-access methodology.

Staphylococcus aureus α-toxin impairs early neutrophil localization via electrogenic disruption of store-operated calcium entry.

The pore-forming S. aureus α-toxin (Hla) contributes to virulence and disease pathogenesis. While high concentrations of toxin induce cell death, neutrophils exhibit relative resistance to lysis, suggesting that the action of Hla may not be solely conferred by lytic susceptibility. Using intravital microscopy, we observed that Hla disrupts neutrophil localization and clustering early in infection. Hla forms a narrow, ion-selective pore, suggesting that Hla may dysregulate calcium or other ions to impair neutrophil function. We found that sub-lytic Hla did not permit calcium influx but caused rapid membrane depolarization. Depolarization decreases the electrogenic driving force for calcium, and concordantly, Hla suppressed calcium signaling in vitro and in vivo and calcium-dependent leukotriene B4 (LTB4) production, a key mediator of neutrophil clustering. Thus, Hla disrupts the early patterning of the neutrophil response to infection, in part through direct impairment of neutrophil calcium signaling. This early mis-localization of neutrophils may contribute to establishment of infection.

Harnessing a 4-Formyl-Aniline Handle to Tune the Stability of a DNA Aptamer-Protein Complex via Fluorescent Surrogates.

Interactions between DNA aptamers and protein targets hold promise for the development of pharmaceuticals and diagnostics. As such, the utilization of fluorescent nucleobase surrogates in studying aptamer-protein interactions is a powerful tool due to their ability to provide site-specific information through turn-on fluorescence. Unfortunately, previously described turn-on probes serving as nucleobase replacements have only been strongly disruptive to the affinity of aptamer-protein interactions. Herein, we present a modified TBA15 aptamer for thrombin containing a fluorescent surrogate that provides site-specific turn-on emission with low nanomolar affinity. The modification, referred to as AnBtz, was substituted at position T3 and provided strong turn-on emission (Irel ≈ 4) and brightness (ε·Φ > 20 000 cm-1 M-1) with an apparent dissociation constant (Kd) of 15 nM to afford a limit of detection (LOD) of 10 nM for thrombin in 20% human serum. The probe was selected through a modular "on-strand" synthesis process that utilized a 4-formyl-aniline (4FA) handle. Using this platform, we were able to enhance the affinity of the final aptamer conjugate by ∼30-fold in comparison with the initial conjugate design. Molecular dynamics simulations provide insight into the structural basis for this phenomenon and highlight the importance of targeting hydrophobic protein binding sites with fluorescent nucleobase surrogates to create new contacts with protein targets.