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result(s) for
"Verma, Mohan K. S."
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A therapeutic convection–enhanced macroencapsulation device for enhancing β cell viability and insulin secretion
by
Yang, Kisuk
,
Liu, Sophie S.
,
Hamilos, Allison E.
in
Animals
,
Applied Biological Sciences
,
Beta cells
2021
Islet transplantation for type 1 diabetes treatment has been limited by the need for lifelong immunosuppression regimens. This challenge has prompted the development of macroencapsulation devices (MEDs) to immunoprotect the transplanted islets. While promising, conventional MEDs are faced with insufficient transport of oxygen, glucose, and insulin because of the reliance on passive diffusion. Hence, these devices are constrained to two-dimensional, wafer-like geometries with limited loading capacity to maintain cells within a distance of passive diffusion. We hypothesized that convective nutrient transport could extend the loading capacity while also promoting cell viability, rapid glucose equilibration, and the physiological levels of insulin secretion. Here, we showed that convective transport improves nutrient delivery throughout the device and affords a three-dimensional capsule geometry that encapsulates 9.7-fold-more cells than conventional MEDs. Transplantation of a convection-enhanced MED (ceMED) containing insulin-secreting β cells into immunocompetent, hyperglycemic rats demonstrated a rapid, vascular-independent, and glucose-stimulated insulin response, resulting in early amelioration of hyperglycemia, improved glucose tolerance, and reduced fibrosis. Finally, to address potential translational barriers, we outlined future steps necessary to optimize the ceMED design for long-term efficacy and clinical utility.
Journal Article
A resistance-sensing mechanical injector for the precise delivery of liquids to target tissue
2019
The precision of the delivery of therapeutics to the desired injection site by syringes and hollow needles typically depends on the operator. Here, we introduce a highly sensitive, completely mechanical and cost-effective injector for targeting tissue reliably and precisely. As the operator pushes the syringe plunger, the injector senses the loss-of-resistance on encountering a softer tissue or a cavity, stops advancing the needle and delivers the payload. We demonstrate that the injector can reliably deliver liquids to the suprachoroidal space—a challenging injection site that provides access to the back of the eye—for a wide range of eye sizes, scleral thicknesses and intraocular pressures, and target sites relevant for epidural injections, subcutaneous injections and intraperitoneal access. The design of this simple and effective injector can be adapted for a broad variety of clinical applications.
A mechanical injector that targets tissue by sensing the loss-of-resistance on encountering softer tissue or a cavity can reliably and precisely deliver liquids to the suprachoroidal space, and to other injection-accessible target sites in the body.
Journal Article
A DFT Study on Armchair Nanoribbon Structures of TiN, ZrN, and HfN
by
Verma, Mohan L
,
Bhadoria, Bhagirath Singh
,
Tiwari, Ashish
in
Bulk density
,
Computer storage devices
,
Corrosion
2024
The atomic structures, growth patterns, new spintronic, magneto-optic, and electrical properties of 2D armchair nanoribbons of group-IV transition metal nitrides (TiN, ZrN, and HfN) have been investigated. The atomic unit cells of TiN, ZrN, HfN, TiZrN, TiHfN, and ZrHfN have been transformed into the matching armchair nanoribbons. By comparing the proposed nanoribbon to the bulk and monolayer structures of these metal nitrides, the structural stability, density, and projected density of states, band structure, magnetic behavior, and polarization were evaluated. The outcomes demonstrate that, in comparison to the crystalline structure, the suggested systems exhibit ferrimagnetic behavior and a remarkable magnetic moment. Also, a higher magnetic moment of about 24 μB in the supercells of the suggested nanoribbons was discovered due to the increased atom count. The proposed structures demonstrated indirect band gap semiconductor capabilities in the range between 1.66 eV and 2.16 eV which is again an unknown phenomenon in the bulk structure of transition metal nitrides. Owing to these characteristics, the proposed structures can be employed in many optoelectronic applications, such as solar cell devices, LEDs, laser diodes, and optical fibers where the band gap is the key requirement. Apart from this, they can also be useful in coating biomedical implanted chips, transformers, switches, and batteries. Memory storage devices will also benefit from the unique characteristics of the proposed nanoribbon structures.
Journal Article
A holistic seismotectonic model of Delhi region
2021
Delhi region in northern India experiences frequent shaking due to both far-field and near-field earthquakes from the Himalayan and local sources, respectively. The recent M3.5 and M3.4 earthquakes of 12th April 2020 and 10th May 2020 respectively in northeast Delhi and M4.4 earthquake of 29th May 2020 near Rohtak (~ 50 km west of Delhi), followed by more than a dozen aftershocks, created panic in this densely populated habitat. The past seismic history and the current activity emphasize the need to revisit the subsurface structural setting and its association with the seismicity of the region. Fault plane solutions are determined using data collected from a dense network in Delhi region. The strain energy released in the last two decades is also estimated to understand the subsurface structural environment. Based on fault plane solutions, together with information obtained from strain energy estimates and the available geophysical and geological studies, it is inferred that the Delhi region is sitting on two contrasting structural environments: reverse faulting in the west and normal faulting in the east, separated by the NE-SW trending Delhi Hardwar Ridge/Mahendragarh-Dehradun Fault (DHR-MDF). The WNW-ESE trending Delhi Sargoda Ridge (DSR), which intersects DHR-MDF in the west, is inferred as a thrust fault. The transfer of stress from the interaction zone of DHR-MDF and DSR to nearby smaller faults could further contribute to the scattered shallow seismicity in Delhi region.
Journal Article
Safety and immunogenicity of an inactivated SARS-CoV-2 vaccine, BBV152: a double-blind, randomised, phase 1 trial
2021
To mitigate the effects of COVID-19, a vaccine is urgently needed. BBV152 is a whole-virion inactivated SARS-CoV-2 vaccine formulated with a toll-like receptor 7/8 agonist molecule adsorbed to alum (Algel-IMDG) or alum (Algel).
We did a double-blind, multicentre, randomised, controlled phase 1 trial to assess the safety and immunogenicity of BBV152 at 11 hospitals across India. Healthy adults aged 18–55 years who were deemed healthy by the investigator were eligible. Individuals with positive SARS-CoV-2 nucleic acid and/or serology tests were excluded. Participants were randomly assigned to receive either one of three vaccine formulations (3 μg with Algel-IMDG, 6 μg with Algel-IMDG, or 6 μg with Algel) or an Algel only control vaccine group. Block randomisation was done with a web response platform. Participants and investigators were masked to treatment group allocation. Two intramuscular doses of vaccines were administered on day 0 (the day of randomisation) and day 14. Primary outcomes were solicited local and systemic reactogenicity events at 2 h and 7 days after vaccination and throughout the full study duration, including serious adverse events. Secondary outcome was seroconversion (at least four-fold increase from baseline) based on wild-type virus neutralisation. Cell-mediated responses were evaluated by intracellular staining and ELISpot. The trial is registered at ClinicalTrials.gov (NCT04471519).
Between July 13 and 30, 2020, 827 participants were screened, of whom 375 were enrolled. Among the enrolled participants, 100 each were randomly assigned to the three vaccine groups, and 75 were randomly assigned to the control group (Algel only). After both doses, solicited local and systemic adverse reactions were reported by 17 (17%; 95% CI 10·5–26·1) participants in the 3 μg with Algel-IMDG group, 21 (21%; 13·8–30·5) in the 6 μg with Algel-IMDG group, 14 (14%; 8·1–22·7) in the 6 μg with Algel group, and ten (10%; 6·9–23·6) in the Algel-only group. The most common solicited adverse events were injection site pain (17 [5%] of 375 participants), headache (13 [3%]), fatigue (11 [3%]), fever (nine [2%]), and nausea or vomiting (seven [2%]). All solicited adverse events were mild (43 [69%] of 62) or moderate (19 [31%]) and were more frequent after the first dose. One serious adverse event of viral pneumonitis was reported in the 6 μg with Algel group, unrelated to the vaccine. Seroconversion rates (%) were 87·9, 91·9, and 82·8 in the 3 μg with Algel-IMDG, 6 μg with Algel-IMDG, and 6 μg with Algel groups, respectively. CD4+ and CD8+ T-cell responses were detected in a subset of 16 participants from both Algel-IMDG groups.
BBV152 led to tolerable safety outcomes and enhanced immune responses. Both Algel-IMDG formulations were selected for phase 2 immunogenicity trials. Further efficacy trials are warranted.
Bharat Biotech International.
Journal Article
Safety and immunogenicity of an inactivated SARS-CoV-2 vaccine, BBV152: interim results from a double-blind, randomised, multicentre, phase 2 trial, and 3-month follow-up of a double-blind, randomised phase 1 trial
2021
BBV152 is a whole-virion inactivated SARS-CoV-2 vaccine (3 μg or 6 μg) formulated with a toll-like receptor 7/8 agonist molecule (IMDG) adsorbed to alum (Algel). We previously reported findings from a double-blind, multicentre, randomised, controlled phase 1 trial on the safety and immunogenicity of three different formulations of BBV152 (3 μg with Algel-IMDG, 6 μg with Algel-IMDG, or 6 μg with Algel) and one Algel-only control (no antigen), with the first dose administered on day 0 and the second dose on day 14. The 3 μg and 6 μg with Algel-IMDG formulations were selected for this phase 2 study. Herein, we report interim findings of the phase 2 trial on the immunogenicity and safety of BBV152, with the first dose administered on day 0 and the second dose on day 28.
We did a double-blind, randomised, multicentre, phase 2 clinical trial to evaluate the immunogenicity and safety of BBV152 in healthy adults and adolescents (aged 12–65 years) at nine hospitals in India. Participants with positive SARS-CoV-2 nucleic acid and serology tests were excluded. Participants were randomly assigned (1:1) to receive either 3 μg with Algel-IMDG or 6 μg with Algel-IMDG. Block randomisation was done by use of an interactive web response system. Participants, investigators, study coordinators, study-related personnel, and the sponsor were masked to treatment group allocation. Two intramuscular doses of vaccine were administered on day 0 and day 28. The primary outcome was SARS-CoV-2 wild-type neutralising antibody titres and seroconversion rates (defined as a post-vaccination titre that was at least four-fold higher than the baseline titre) at 4 weeks after the second dose (day 56), measured by use of the plaque-reduction neutralisation test (PRNT50) and the microneutralisation test (MNT50). The primary outcome was assessed in all participants who had received both doses of the vaccine. Cell-mediated responses were a secondary outcome and were assessed by T-helper-1 (Th1)/Th2 profiling at 2 weeks after the second dose (day 42). Safety was assessed in all participants who received at least one dose of the vaccine. In addition, we report immunogenicity results from a follow-up blood draw collected from phase 1 trial participants at 3 months after they received the second dose (day 104). This trial is registered at ClinicalTrials.gov, NCT04471519.
Between Sept 5 and 12, 2020, 921 participants were screened, of whom 380 were enrolled and randomly assigned to the 3 μg with Algel-IMDG group (n=190) or 6 μg with Algel-IMDG group (n=190). Geometric mean titres (GMTs; PRNT50) at day 56 were significantly higher in the 6 μg with Algel-IMDG group (197·0 [95% CI 155·6–249·4]) than the 3 μg with Algel-IMDG group (100·9 [74·1–137·4]; p=0·0041). Seroconversion based on PRNT50 at day 56 was reported in 171 (92·9% [95% CI 88·2–96·2] of 184 participants in the 3 μg with Algel-IMDG group and 174 (98·3% [95·1–99·6]) of 177 participants in the 6 μg with Algel-IMDG group. GMTs (MNT50) at day 56 were 92·5 (95% CI 77·7–110·2) in the 3 μg with Algel-IMDG group and 160·1 (135·8–188·8) in the 6 μg with Algel-IMDG group. Seroconversion based on MNT50 at day 56 was reported in 162 (88·0% [95% CI 82·4–92·3]) of 184 participants in the 3 μg with Algel-IMDG group and 171 (96·6% [92·8–98·8]) of 177 participants in the 6 μg with Algel-IMDG group. The 3 μg with Algel-IMDG and 6 μg with Algel-IMDG formulations elicited T-cell responses that were biased to a Th1 phenotype at day 42. No significant difference in the proportion of participants who had a solicited local or systemic adverse reaction in the 3 μg with Algel-IMDG group (38 [20·0%; 95% CI 14·7–26·5] of 190) and the 6 μg with Algel-IMDG group (40 [21·1%; 15·5–27·5] of 190) was observed on days 0–7 and days 28–35; no serious adverse events were reported in the study. From the phase 1 trial, 3-month post-second-dose GMTs (MNT50) were 39·9 (95% CI 32·0–49·9) in the 3μg with Algel-IMDG group, 69·5 (53·7–89·9) in the 6 μg with Algel-IMDG group, 53·3 (40·1–71·0) in the 6 μg with Algel group, and 20·7 (14·5–29·5) in the Algel alone group.
In the phase 1 trial, BBV152 induced high neutralising antibody responses that remained elevated in all participants at 3 months after the second vaccination. In the phase 2 trial, BBV152 showed better reactogenicity and safety outcomes, and enhanced humoral and cell-mediated immune responses compared with the phase 1 trial. The 6 μg with Algel-IMDG formulation has been selected for the phase 3 efficacy trial.
Bharat Biotech International.
For the Hindi translation of the abstract see Supplementary Materials section.
Journal Article
An Insight into Strain-Specificity of Streptomyces chrestomyceticus ADP4 and Identification of a Novel Peptide with Potential Antiviral Activities Against Significant Human Viruses, Including SARS-CoV2, HCV, and HIV
by
Mohan, Medicherla Krishna
,
Verma, Varsha
,
Dubey, Ashok K.
in
Annotations
,
Antimicrobial agents
,
Antiviral activity
2025
This study aimed to unravel the genomic uniqueness of Streptomyces chrestomyceticus ADP4 using whole-genome sequence analysis, with a focus on identifying strain-specific genes/proteins associated with a novel therapeutic source. The genome of the strain ADP4 was sequenced and assembled to a total size of 9.64 MB. A total of 8378 coding regions were identified. Strain ADP4 was found to be clustered into a clade of the species S. chrestomyceticus. Fifty-one biosynthetic gene clusters were predicted in the genome of the strain ADP4, and three of them were common to all the strains of S. chrestomyceticus. A comparative metabolic profile of S. chrestomyceticus revealed a unique metabolic protein, supporting strain-level variations. Comparative genome analysis led to the identification of the genomic sequences that were specific to the strain ADP4. These strain-specific unique sequences of ADP4 were identified across the available data, underscoring their distinct genetic identity. Among these eight functionally uncharacterized hypothetical proteins (HPs), only two could be assigned with functional attributes, wherein one of them, HP2, was ascertained to be a peptide with possible antiviral activity, underscoring its potential as a novel drug candidate for aantiviraltherapy. The structural validation and peptide–protein molecular docking have evidently demonstrated anantiviralctivity of HP2 against significant human viral pathogens, for example, HIV, SARS-CoV2, HCV, ZIKV, JEV, and DENV.
Journal Article
Key learnings from an outcome and embedded process evaluation of a direct to beneficiary mobile health intervention among marginalised women in rural Bihar, India
2022
IntroductionMobile Vaani was implemented as a pilot programme across six blocks of Nalanda district in Bihar state, India to increase knowledge of rural women who were members of self-help groups on proper nutrition for pregnant or lactating mothers and infants, family planning and diarrhoea management. Conveners of self-help group meetings, community mobilisers, introduced women to the intervention by giving them access to interactive voice response informational and motivational content. A mixed methods outcome and embedded process evaluation was commissioned to assess the reach and impact of Mobile Vaani.MethodsThe outcome evaluation, conducted from January 2017 to November 2018, used a quasi-experimental pre–post design with a sample of 4800 married women aged 15–49 from self-help group households, who had a live birth in the past 24 months. Surveys with community mobilisers followed by meeting observations (n=116), in-depth interviews (n=180) with self-help group members and secondary analyses of system generated data were conducted to assess exposure and perceptions of the intervention.ResultsFrom the outcome evaluation, 23% of women interviewed had heard about Mobile Vaani. Women in the intervention arm had significantly higher knowledge than women in the comparison arm for two of seven focus outcomes: knowledge of how to make child’s food nutrient and energy dense (treatment-on-treated: 18.8% (95% CI 0.4% to 37.2%, p<0.045)) and awareness of at least two modern spacing family planning methods (treatment-on-treated: 17.6% (95% CI 4.7% to 30.5%, p<0.008)). Women with any awareness of Mobile Vaani were happy with the programme and appreciated the ability to call in and listen to the content.ConclusionLow population awareness and programme exposure are underpinned by broader population level barriers to mobile phone access and use among women and missed opportunities by the programme to improve targeting and programme promotion. Further research is needed to assess programmatic linkages with changes in health practices.
Journal Article
Incorporation of Putative Helix-Breaking Amino Acids in the Design of Novel Stapled Peptides: Exploring Biophysical and Cellular Permeability Properties
by
Brown, Christopher J.
,
Kannan, Srinivasaraghavan
,
Ferrer, Fernando
in
Amino Acid Sequence - genetics
,
Amino Acid Substitution - genetics
,
Amino acids
2019
Stapled α-helical peptides represent an emerging superclass of macrocyclic molecules with drug-like properties, including high-affinity target binding, protease resistance, and membrane permeability. As a model system for probing the chemical space available for optimizing these properties, we focused on dual Mdm2/MdmX antagonist stapled peptides related to the p53 N-terminus. Specifically, we first generated a library of ATSP-7041 (Chang et al., 2013) analogs iteratively modified by L-Ala and D-amino acids. Single L-Ala substitutions beyond the Mdm2/(X) binding interfacial residues (i.e., Phe3, Trp7, and Cba10) had minimal effects on target binding, α-helical content, and cellular activity. Similar binding affinities and cellular activities were noted at non-interfacial positions when the template residues were substituted with their d-amino acid counterparts, despite the fact that d-amino acid residues typically ‘break’ right-handed α-helices. d-amino acid substitutions at the interfacial residues Phe3 and Cba10 resulted in the expected decreases in binding affinity and cellular activity. Surprisingly, substitution at the remaining interfacial position with its d-amino acid equivalent (i.e., Trp7 to d-Trp7) was fully tolerated, both in terms of its binding affinity and cellular activity. An X-ray structure of the d-Trp7-modified peptide was determined and revealed that the indole side chain was able to interact optimally with its Mdm2 binding site by a slight global re-orientation of the stapled peptide. To further investigate the comparative effects of d-amino acid substitutions we used linear analogs of ATSP-7041, where we replaced the stapling amino acids by Aib (i.e., R84 to Aib4 and S511 to Aib11) to retain the helix-inducing properties of α-methylation. The resultant analog sequence Ac–Leu–Thr–Phe–Aib–Glu–Tyr–Trp–Gln–Leu–Cba–Aib–Ser–Ala–Ala–NH2 exhibited high-affinity target binding (Mdm2 Kd = 43 nM) and significant α-helicity in circular dichroism studies. Relative to this linear ATSP-7041 analog, several d-amino acid substitutions at Mdm2(X) non-binding residues (e.g., d-Glu5, d-Gln8, and d-Leu9) demonstrated decreased binding and α-helicity. Importantly, circular dichroism (CD) spectroscopy showed that although helicity was indeed disrupted by d-amino acids in linear versions of our template sequence, stapled molecules tolerated these residues well. Further studies on stapled peptides incorporating N-methylated amino acids, l-Pro, or Gly substitutions showed that despite some positional dependence, these helix-breaking residues were also generally tolerated in terms of secondary structure, binding affinity, and cellular activity. Overall, macrocyclization by hydrocarbon stapling appears to overcome the destabilization of α-helicity by helix breaking residues and, in the specific case of d-Trp7-modification, a highly potent ATSP-7041 analog (Mdm2 Kd = 30 nM; cellular EC50 = 600 nM) was identified. Our findings provide incentive for future studies to expand the chemical diversity of macrocyclic α-helical peptides (e.g., d-amino acid modifications) to explore their biophysical properties and cellular permeability. Indeed, using the library of 50 peptides generated in this study, a good correlation between cellular permeability and lipophilicity was observed.
Journal Article
Persistence of immunity and impact of third dose of inactivated COVID-19 vaccine against emerging variants
2022
This is a comprehensive report on immunogenicity of COVAXIN
®
booster dose against ancestral and Variants of Concern (VOCs) up to 12 months. It is well known that neutralizing antibodies induced by COVID-19 vaccines wane within 6 months of vaccination leading to questions on the effectiveness of two-dose vaccination against breakthrough infections. Therefore, we assessed the persistence of immunogenicity up to 6 months after a two or three-dose with BBV152 and the safety of a booster dose in an ongoing phase 2, double-blind, randomized controlled trial (ClinicalTrials.gov: NCT04471519). We report persistence of humoral and cell mediated immunity up to 12 months of vaccination, despite decline in the magnitude of antibody titers. Administration of a third dose of BBV152 increased neutralization titers against both homologous (D614G) and heterologous strains (Alpha, Beta, Delta, Delta Plus and Omicron) with a slight increase in B cell memory responses. Thus, seronversion rate remain high in boosted recipients compared to non-booster, even after 6 months, post third dose against variants. No serious adverse events observed, except pain at the injection site, itching and redness. Hence, these results indicate that a booster dose of BBV152 is safe and necessary to ensure persistent immunity to minimize breakthrough infections of COVID-19, due to newly emerging variants.
Trial registration:
Registered with the Clinical Trials Registry (India) No. CTRI/2021/04/032942, dated 19/04/2021 and on Clinicaltrials.gov: NCT04471519.
Journal Article