Effect of the Nanorough Surface of TiO2 Thin Films on the Compatibility with Endothelial Cells.

The cytocompatibility of titanium oxides (TiO2) and oxynitrides (N-TiO2, TiOxNy) thin films depends heavily on the surface topography. Considering that the initial relief of the substrate and the coating are summed up in the final topography of the surface, it can be expected that the same sputtering modes result in different surface topography if the substrate differs. Here, we investigated the problem by examining 16 groups of samples differing in surface topography; 8 of them were hand-abraded and 8 were machine-polished. Magnetron sputtering was performed in a reaction gas medium with various N2:O2 ratios and bias voltages. Abraded and polished uncoated samples served as controls. The surfaces were studied using atomic force microscopy (AFM). The cytocompatibility of coatings was evaluated in terms of cytotoxicity, adhesion, viability, and NO production. It has been shown that the cytocompatibility of thin films largely depends on the surface nanostructure. Both excessively low and excessively high density of peaks, high and low kurtosis of height distribution (Sku), and low rates of mean summit curvature (Ssc) have a negative effect. Optimal cytocompatibility was demonstrated by abraded surface with a TiOxNy thin film sputtered at N2:O2 = 1:1 and Ub = 0 V. The nanopeaks of this surface had a maximum height, a density of about 0.5 per 1 µm2, Sku from 4 to 5, and an Ssc greater than 0.6. We believe that the excessive sharpness of surface nanostructures formed during magnetron sputtering of TiO2 and N-TiO2 films, especially at a high density of these structures, prevents both adhesion of endothelial cells, and their further proliferation and functioning. This effect is apparently due to damage to the cell membrane. At low height, kurtosis, and peak density, the main factor affecting the cell/surface interface is inefficient cell adhesion.

Primary hyperparathyroidism in young patients is associated with metabolic disorders: a prospective comparative study.

BACKGROUND: Components of metabolic syndrome can be observed in patients with primary hyperparathyroidism (PHPT). The link between these disorders remains unclear due to the lack of relevant experimental models and the heterogeneity of examined groups. The effect of surgery on metabolic abnormalities is also controversial. We conducted a comprehensive assessment of metabolic parameters in young patients with PHPT. METHODS: One-center prospective comparative study was carried out. The participants underwent a complex biochemical and hormonal examination, a hyperinsulinemic euglycemic and hyperglycemic clamps, a bioelectrical impedance analysis of the body composition before and 13 months after parathyroidectomy compared to sex-, age- and body mass index matched healthy volunteers. RESULTS: 45.8% of patients (n = 24) had excessive visceral fat. Insulin resistance was detected in 54.2% of cases. PHPT patients had higher serum triglycerides, lower M-value and higher C-peptide and insulin levels in both phases of insulin secretion compared to the control group (p < 0.05 for all parameters). There were tendencies to decreased fasting glucose (p = 0.031), uric acid (p = 0.044) and insulin levels of the second secretion phase (p = 0.039) after surgery, but no statistically significant changes of lipid profile and M-value as well as body composition were revealed. We obtained negative correlations between percent body fat and osteocalcin and magnesium levels in patients before surgery. CONCLUSION: PHPT is associated with insulin resistance that is the main risk factor of serious metabolic disorders. Surgery may potentially improve carbohydrate and purine metabolism.

The efficacy and safety of GP40081 (insulin aspart biphasic 30) compared with NovoMix® 30 in Type 2 diabetes patients.

Aim: To evaluate the safety and efficacy of insulin Aspart-Mix biosimilar candidate GP40081 (GP-Asp30) compared with NovoMix® 30 (NN-Asp30). Materials & methods: In a randomized open-label, active-controlled, 26-week non-inferiority clinical trial 264 patients with Type 2 diabetes mellitus were randomized 1:1 to receive once-daily GP-Asp30 or NN-Asp30. The primary safety end point was the immune response rate. Efficacy outcomes were a mean change in HbA1c (primary), frequency of achieving a glycemic g fasting plasma glucose levels, 7-point glucose profiles, and insulin doses. Results: The immune response developed in 10/126 (8%) participants in the GP-Asp30 group and in 10/125 (8%) participants in the NN-Asp30 group (p = 1.000). The mean difference in HbA1c change between groups was 0.12 (95%CI [-0.14, 0.38]). Other secondary efficacy and safety outcomes weren't statistically different between the two groups. Conclusion: GP-Asp30 demonstrated similar safety and efficacy compared with NN-Asp30 and may be considered a biosimilar insulin.

Clinical Pharmacology of Insulin Aspart Biosimilar GP40071: Pharmacokinetic/Pharmacodynamic Comparability in Hyperinsulinemic Euglycemic Clamp Procedure.

Insulin aspart is a short-acting insulin analogue that is used to control postprandial glycemia levels in diabetic patients. The aim of this clinical trial was to compare the pharmacokinetics and pharmacodynamics of GP40071 (GP-Asp) and NovoRapid Penfill (Novo-Asp) in a hyperinsulinemic euglycemic clamp (HEC). This trial was conducted as a part of a GP40071 biosimilar clinical development program. This was a phase I randomized, double-blind, two-period crossover study. Twenty-six healthy male volunteers aged 18 to 45 years who met the inclusion criteria underwent the procedure of an HEC following a single subcutaneous injection of 0.3 IU/kg of either GP-Asp or Novo-Asp into the abdomen. After doses, plasma glucose levels were monitored every 5 minutes for 8 hours. The adjustment of the glucose infusion rate (GIR) was based on the blood glucose measurements. The GIR values were used to evaluate the PD profiles of the studied drugs. Regular blood sampling was performed during the study to obtain sufficient pharmacokinetic data. The 90% confidence intervals for the geometric mean ratios of the pharmacokinetic (AUCins.0-t , Cins.max ) and pharmacodynamic (GIRmax , AUCGIR0-t ) parameters of GP-Asp were within the 80%-125% comparability limits. The safety profiles of the drugs were also comparable. Bioequivalence, similar PD, and safety of GP-Asp and Novo-Asp were demonstrated.

The Effect of Adding Modified Chitosan on the Strength Properties of Bacterial Cellulose for Clinical Applications.

Currently, several materials for the closure of the dura mater (DM) defects are known. However, the long-term results of their usage reveal a number of disadvantages. The use of antibiotics and chitosan is one of the major trends in solving the problems associated with infectious after-operational complications. This work compares the mechanical properties of samples of bacterial nanocellulose (BNC) impregnated with Novochizol™ and vancomycin with native BNC and preserved and native human DM. An assessment of the possibility of controling the mechanical properties of these materials by changing their thickness has been performed by statistical analysis methods. A total of 80 specimens of comparable samples were investigated. During the analysis, the results obtained, the factor of Novochizol™ addition has provided a statistically significant impact on the strength properties (Fisher Criteria p-value 0.00509 for stress and 0.00112 for deformation). Moreover, a stronger relationship between the thickness of the samples and their ultimate load was shown: R2=0.236 for BNC + Novochizol™ + vancomycin, compared to R2=0.0405 for native BNC. Using factor analysis, it was possible to show a significant effect of modified chitosan (Novochizol™) on the ultimate stress (p-value = 0.005).

Safety and efficacy of GP40071 compared with originator insulin aspart (NovoRapid® Penfill®) in Type 1 diabetes mellitus.

Aim: To compare safety and efficacy of GP40071 insulin aspart (GP-Asp) and NovoRapid® (NN-Asp). Materials & methods: This randomized open-label, active-controlled, 26-week non-inferiority Phase III clinical trial enrolled 264 Type 1 diabetes mellitus patients (HbA1c: 7.1-12.0%) randomized 1:1 to once daily GP-Asp (n = 132) or NN-Asp (n = 132). The primary safety end point was immune response at week 26. Results: The groups were similar in frequency of immune response (p = 0.323) and in other safety end points. Mean HbA1c change from baseline was -0.57% for GP-Asp and -0.56% for NN-Asp and did not differ between groups (p = 0.955). Intergroup mean difference of HbA1c level change (95% CI) at week 26 from baseline was 0.00 (-0.26, 0.25) %. Insulin doses, fasting plasma glucose levels and seven-point glucose profiles were similar between groups (p > 0.05). The number of patients experiencing hypoglycemic episodes did not differ between the groups (p = 0.497). Conclusion: GP-Asp demonstrated similar safety and efficacy. Trial registration number: NCT04079413 (ClinicalTrials.gov).

Identifying the unmet needs of individuals with Type 2 diabetes: an international web-based survey.

Aim: To identify and understand the main unmet needs of individuals with Type 2 diabetes (T2D). Materials & methods: An online survey was conducted in Brazil, China and Russia of individuals with recently diagnosed T2D. Results: The survey, involving 300 individuals with T2D, identified a need for more information regarding food/diet and for increased awareness of T2D symptoms. While most participants (94%) had experienced symptoms prior to their diagnosis, only 55% of symptomatic individuals sought medical attention. Conclusion: Novel strategies to increase awareness of diabetes should be developed and tested, and may enable earlier diagnosis and improve patients' quality of life.

Lay abstract Type 2 diabetes (T2D) negatively impacts an individual's health-related quality of life and represents a significant burden of disease worldwide. Although previous studies have examined the unmet needs of patients with diabetes, no recent studies have evaluated the needs of individuals with T2D in Brazil, China or Russia. This study used an online questionnaire to identify and understand the main unmet needs of individuals who had been recently diagnosed with T2D from these countries. Several potential needs were identified, including the need for more information and support about food and diet, a new noninvasive solution for blood glucose monitoring and increased awareness of T2D symptoms. Our study also identified possible innovative solution to address these needs.

Antiviral photodynamic therapy: Inactivation and inhibition of SARS-CoV-2 in vitro using methylene blue and Radachlorin.

INTRODUCTION: Recently, the COVID-19 pandemic has spread globally, necessitating the development of new methods for its prevention and treatment. The purpose of this study was to evaluate the antiviral activity of photodynamic therapy (PDT) against SARS-CoV-2 in vitro. METHODS: Vero E6 cells and SARS-CoV-2 isolated in Russia were used for PDT with methylene blue (MB) and Radachlorin. A continuous laser with wavelength λ = 662 nm in doses of 16 J/cm2 and 40 J/cm2 laser irradiation was used for PDT of a viral suspension and SARS-CoV-2-infected cells. The direct cytopathogenic effect of SARS-CoV-2 was evaluated via light microscopy to calculate the TCID50 in the samples and perform statistical analysis. RESULTS: Viral suspensions of SARS-CoV-2 that had a TCID50 greater than 103 were inactivated by PDT in the presence of MB and Radachlorin. Vero E6 cells were protected from 104 TCID50 of SARS-CoV-2 by PDT post infection. The range of protective concentrations was 1.0-10.0 µg/ml and 0.5-5.0 µg/ml for MB and Radachlorin, respectively. Additionally, it was found that MB and Radachlorin also possess significant antiviral activity even without PDT. The 50 % inhibitory concentration (IC50) against 102 TCID50 of SARS-CoV-2 was found to be 0.22 and 0.33 µg/mL with the addition of MB and Radachlorin, respectively, to cells concomitantly with virus, whereas in the case of applying the photosensitizers at 3.5 h post infection, the IC50 was 0.6 and 2.0 µg/mL for MB and Radachlorin, respectively. CONCLUSION: PDT shows high antiviral activity against SARS-CoV-2 when combined with MB and Radachlorin in vitro.

Heteromoiré Engineering on Magnetic Bloch Transport in Twisted Graphene Superlattices.

Localized electrons subject to applied magnetic fields can restart to propagate freely through the lattice in delocalized magnetic Bloch states (MBSs) when the lattice periodicity is commensurate with the magnetic length. Twisted graphene superlattices with moiré wavelength tunability enable experimental access to the unique delocalization in a controllable fashion. Here, we report the observation and characterization of high-temperature Brown-Zak (BZ) oscillations which come in two types, 1/B and B periodicity, originating from the generation of integer and fractional MBSs, in the twisted bilayer and trilayer graphene superlattices, respectively. Coexisting periodic-in-1/B oscillations assigned to different moiré wavelengths are dramatically observed in small-angle twisted bilayer graphene, which may arise from angle-disorder-induced in-plane heteromoiré superlattices. Moreover, the vertical stacking of heteromoiré supercells in double-twisted trilayer graphene results in a mega-sized superlattice. The exotic superlattice contributes to the periodic-in-B oscillation and dominates the magnetic Bloch transport.

Safety and efficacy of GP40061 compared with originator insulin glargine (Lantus®): a randomized open-label clinical trial.

Aim: To compare safety (immunogenicity) and efficacy of GP40061 insulin glargine (GP-Gla) and Lantus® (Sanofi glargine, Sa-Gla) in people with diabetes mellitus. Materials & methods: This randomized open-label, 26-week clinical trial enrolled 180 Type 1 diabetes mellitus patients (HbA1c 6.5-12.0%), randomized 1:1 to once daily GP-Gla (n = 90) or Sa-Gla (n = 90). The primary end point was immune response at 26th week. Results: The frequency of immune response was similar in GP-Gla and Sa-Gla (p = 1.000). Groups were similar in terms of other safety end points. Mean HbA1c change from baseline was -0.66% for GP-Gla and -0.77% for Sa-Gla, and did not differ between groups (p = 0.326). Insulin doses, fasting plasma glucose and seven-point glucose profiles were similar between groups. Conclusion: GP-Gla and Sa-Gla demonstrated similar safety and efficacy. ClinicalTrials.gov Identifier: NCT04022993.

Synthesis and properties of free-standing monolayer amorphous carbon.

Bulk amorphous materials have been studied extensively and are widely used, yet their atomic arrangement remains an open issue. Although they are generally believed to be Zachariasen continuous random networks1, recent experimental evidence favours the competing crystallite model in the case of amorphous silicon2-4. In two-dimensional materials, however,  the corresponding questions remain unanswered. Here we report the synthesis, by laser-assisted chemical vapour deposition5, of centimetre-scale, free-standing, continuous and stable monolayer amorphous carbon, topologically distinct from disordered graphene. Unlike in bulk materials, the structure of monolayer amorphous carbon can be determined by atomic-resolution imaging. Extensive characterization by Raman and X-ray spectroscopy and transmission electron microscopy reveals the complete absence of long-range periodicity and a threefold-coordinated structure with a wide distribution of bond lengths, bond angles, and five-, six-, seven- and eight-member rings. The ring distribution is not a Zachariasen continuous random network, but resembles the competing (nano)crystallite model6. We construct a corresponding model that enables density-functional-theory calculations of the properties of monolayer amorphous carbon, in accordance with observations. Direct measurements confirm that it is insulating, with resistivity values similar to those of boron nitride grown by chemical vapour deposition. Free-standing monolayer amorphous carbon is surprisingly stable and deforms to a high breaking strength, without crack propagation from the point of fracture. The excellent physical properties of this stable, free-standing monolayer amorphous carbon could prove useful for permeation and diffusion barriers in applications such as magnetic recording devices and flexible electronics.

Digital quantum simulation of molecular vibrations.

Molecular vibrations underpin important phenomena such as spectral properties, energy transfer, and molecular bonding. However, obtaining a detailed understanding of the vibrational structure of even small molecules is computationally expensive. While several algorithms exist for efficiently solving the electronic structure problem on a quantum computer, there has been comparatively little attention devoted to solving the vibrational structure problem with quantum hardware. In this work, we discuss the use of quantum algorithms for investigating both the static and dynamic vibrational properties of molecules. We introduce a physically motivated unitary vibrational coupled cluster ansatz, which also makes our method accessible to noisy, near-term quantum hardware. We numerically test our proposals for the water and sulfur dioxide molecules.

Clinical Targets for Continuous Glucose Monitoring Data Interpretation: Recommendations From the International Consensus on Time in Range.

Improvements in sensor accuracy, greater convenience and ease of use, and expanding reimbursement have led to growing adoption of continuous glucose monitoring (CGM). However, successful utilization of CGM technology in routine clinical practice remains relatively low. This may be due in part to the lack of clear and agreed-upon glycemic targets that both diabetes teams and people with diabetes can work toward. Although unified recommendations for use of key CGM metrics have been established in three separate peer-reviewed articles, formal adoption by diabetes professional organizations and guidance in the practical application of these metrics in clinical practice have been lacking. In February 2019, the Advanced Technologies & Treatments for Diabetes (ATTD) Congress convened an international panel of physicians, researchers, and individuals with diabetes who are expert in CGM technologies to address this issue. This article summarizes the ATTD consensus recommendations for relevant aspects of CGM data utilization and reporting among the various diabetes populations.

Active Site-Induced Evolutionary Constraints Follow Fold Polarity Principles in Soluble Globular Enzymes.

A recent analysis of evolutionary rates in >500 globular soluble enzymes revealed pervasive conservation gradients toward catalytic residues. By looking at amino acid preference profiles rather than evolutionary rates in the same data set, we quantified the effects of active sites on site-specific constraints for physicochemical traits. We found that conservation gradients respond to constraints for polarity, hydrophobicity, flexibility, rigidity and structure in ways consistent with fold polarity principles; while sites far from active sites seem to experience no physicochemical constraint, rather being highly variable and favoring amino acids of low metabolic cost. Globally, our results highlight that amino acid variation contains finer information about protein structure than usually regarded in evolutionary models, and that this information is retrievable automatically with simple fits. We propose that analyses of the kind presented here incorporated into models of protein evolution should allow for better description of the physical chemistry that underlies molecular evolution.

Gate-Defined Quantum Confinement in InSe-Based van der Waals Heterostructures.

Indium selenide, a post-transition metal chalcogenide, is a novel two-dimensional (2D) semiconductor with interesting electronic properties. Its tunable band gap and high electron mobility have already attracted considerable research interest. Here we demonstrate strong quantum confinement and manipulation of single electrons in devices made from few-layer crystals of InSe using electrostatic gating. We report on gate-controlled quantum dots in the Coulomb blockade regime as well as one-dimensional quantization in point contacts, revealing multiple plateaus. The work represents an important milestone in the development of quality devices based on 2D materials and makes InSe a prime candidate for relevant electronic and optoelectronic applications.

Association of polymorphic markers of genes FTO, KCNJ11, CDKAL1, SLC30A8, and CDKN2B with type 2 diabetes mellitus in the Russian population.

BACKGROUND: The association of type 2 diabetes mellitus (T2DM) with the KCNJ11, CDKAL1, SLC30A8, CDKN2B, and FTO genes in the Russian population has not been well studied. In this study, we analysed the population frequencies of polymorphic markers of these genes. METHODS: The study included 862 patients with T2DM and 443 control subjects of Russian origin. All subjects were genotyped for 10 single nucleotide polymorphisms (SNPs) of the genes using real-time PCR (TaqMan assays). HOMA-IR and HOMA-ß were used to measure insulin resistance and ß-cell secretory function, respectively. RESULTS: The analysis of the frequency distribution of polymorphic markers for genes KCNJ11, CDKAL1, SLC30A8 and CDKN2B showed statistically significant associations with T2DM in the Russian population. The association between the FTO gene and T2DM was not statistically significant. The polymorphic markers rs5219 of the KCNJ11 gene, rs13266634 of the SLC30A8 gene, rs10811661 of the CDKN2B gene and rs9465871, rs7756992 and rs10946398 of the CDKAL1 gene showed a significant association with impaired glucose metabolism or impaired ß-cell function. CONCLUSION: In the Russian population, genes, which affect insulin synthesis and secretion in the ß-cells of the pancreas, play a central role in the development of T2DM.

A glucokinase gene mutation in a young boy with diabetes mellitus, hyperinsulinemia, and insulin resistance.

We report the case of a 12-year-old boy with a glucokinase (GCK) mutation, and diabetes with hyperinsulinemia and insulin resistance. For 4 years, the patient intermittently received insulin medications Actrapid HM and Protaphane HM (total dose 5 U/day), with glycated hemoglobin (HbA1c) levels of 6.6%-7.0%. After extensive screening the patient was found to carry a heterozygous mutation (p.E256K) in GCK (MIM #138079, reference sequence NM_000162.3). Insulin therapy was replaced by metformin at 1,700 mg/day. One year later, his HbA1c level was 6.9%, postprandial glycemia at 120 min of oral glucose tolerance test was 15.4 mmol/L, hyperinsulinemia had increased to 508.9 mU/L, homeostasis model assessment index was 114.2 and the Matsuda index was 0.15. Insulin resistance was confirmed by a hyperinsulinemic euglycemic clamp test - M-index was 2.85 mg/kg/min. This observation is a rare case of one of the clinical variants of diabetes, which should be taken into account by a vigilant endocrinologist due to the need for nonstandard diagnostic and therapeutic approaches.

The Relationship Between Brown Adipose Tissue Content in Supraclavicular Fat Depots and Insulin Sensitivity in Patients with Type 2 Diabetes Mellitus and Prediabetes.

BACKGROUND: The evaluation of brown adipose tissue (BAT) and its role in metabolism and obesity remains an important topic in the recent literature. This study evaluated the influence of the BAT triglyceride content measured by proton magnetic resonance (MR) spectroscopy in patients with type 2 diabetes mellitus (DM2) and prediabetes on insulin sensitivity. METHODS: A total of 25 patients with DM2 and prediabetes (45.9 ± 10.1 years old, body mass index [BMI] of 31.6 ± 5.4 kg/m2) underwent anthropometric measurements (BMI), insulin sensitivity analysis (M value during euglycemic hyperinsulinemic clamp and homeostasis model assessment of insulin resistance), proton MR spectroscopy, and blood tests (total cholesterol, low-density lipoproteins, high-density lipoproteins, and triglycerides). The relationship between the triglyceride content in the supraclavicular fat depot and insulin sensitivity, anthropometric measurements, and blood test results was assessed. RESULTS: The triglyceride content in the supraclavicular fat depot varied between 79.2% and 97.1% (mean: 92.6% ± 4.2%). The triglyceride content in the subcutaneous white adipose tissue of the neck was significantly higher (85.3%-99.3%; mean: 95.5% ± 2.9%; P = 0.0007). The triglyceride content in the supraclavicular fat depot exhibited a significantly moderate correlation with the BMI (r = 0.64; P = 0.0009). A significant weak negative correlation between the supraclavicular fat content and M value was revealed (r = -0.44; P = 0.002). Patients with high insulin resistance (IR) had a higher triglyceride content in the supraclavicular fat depot than patients with normal and lower IR (94.3% ± 2.0% vs. 90.4% ± 5.2%; P = 0.02). CONCLUSIONS: Reducing the BAT content in the supraclavicular fat depot can influence the development of IR in patients with DM2 and prediabetes.

Excitation, detection, and electrostatic manipulation of terahertz-frequency range plasmons in a two-dimensional electron system.

Terahertz frequency time-domain spectroscopy employing free-space radiation has frequently been used to probe the elementary excitations of low-dimensional systems. The diffraction limit, however, prevents its use for the in-plane study of individual laterally-defined nanostructures. Here, we demonstrate a planar terahertz frequency plasmonic circuit in which photoconductive material is monolithically integrated with a two-dimensional electron system. Plasmons with a broad spectral range (up to ~ 400 GHz) are excited by injecting picosecond-duration pulses, generated and detected by a photoconductive semiconductor, into a high mobility two-dimensional electron system. Using voltage modulation of a Schottky gate overlying the two-dimensional electron system, we form a tuneable plasmonic cavity, and observe electrostatic manipulation of the plasmon resonances. Our technique offers a direct route to access the picosecond dynamics of confined electron transport in a broad range of lateral nanostructures.

Efficacy, but not antibody titer or affinity, of a heroin hapten conjugate vaccine correlates with increasing hapten densities on tetanus toxoid, but not on CRM197 carriers.

Vaccines against drugs of abuse have induced antibodies in animals that blocked the biological effects of the drug by sequestering the drug in the blood and preventing it from crossing the blood-brain barrier. Drugs of abuse are too small to induce antibodies and, therefore, require conjugation of drug hapten analogs to a carrier protein. The efficacy of these conjugate vaccines depends on several factors including hapten design, coupling strategy, hapten density, carrier protein selection, and vaccine adjuvant. Previously, we have shown that 1 (MorHap), a heroin/morphine hapten, conjugated to tetanus toxoid (TT) and mixed with liposomes containing monophosphoryl lipid A [L(MPLA)] as adjuvant, partially blocked the antinociceptive effects of heroin in mice. Herein, we extended those findings, demonstrating greatly improved vaccine induced antinociceptive effects up to 3% mean maximal potential effect (%MPE). This was obtained by evaluating the effects of vaccine efficacy of hapten 1 vaccine conjugates with varying hapten densities using two different commonly used carrier proteins, TT and cross-reactive material 197 (CRM197). Immunization of mice with these conjugates mixed with L(MPLA) induced very high anti-1 IgG peak levels of 400-1500 µg/mL that bound to both heroin and its metabolites, 6-acetylmorphine and morphine. Except for the lowest hapten density for each carrier, the antibody titers and affinity were independent of hapten density. The TT carrier based vaccines induced long-lived inhibition of heroin-induced antinociception that correlated with increasing hapten density. The best formulation contained TT with the highest hapten density of ≥30 haptens/TT molecule and induced %MPE of approximately 3% after heroin challenge. In contrast, the best formulation using CRM197 was with intermediate 1 densities (10-15 haptens/CRM197 molecule), but the %MPE was approximately 13%. In addition, the chemical synthesis of 1, the optimization of the conjugation method, and the methods for the accurate quantification of hapten density are described.