Clinical profile and challenges faced in the management of optic neuritis: the Indian scenario.

PURPOSE: Optic neuritis (ON) is a relatively common ophthalmic disease that has recently received renewed attention owing to immunological breakthroughs. We studied the profile of patients with ON with special reference to antibody-mediated ON and the challenges faced in its management. METHODS: Case records of patients with ON presenting to a tertiary eye-care center in South India were analyzed. Data on demographics, presenting visual acuity (VA), clinical features, seropositivity for aquaporin-4 immunoglobulin G (AQP4-IgG) and myelin oligodendrocyte glycoprotein immunoglobulin G (MOG-IgG), details of magnetic resonance imaging (MRI) of orbits and brain, and treatment were collected. RESULTS: Among 138 cases with acute ON, male: female ratio was 1:2. Isolated ON was present in 41.3% of cases. Antibody testing of sera was performed in 68 patients only due to financial limitations. Among these, 48.5% were MOG-IgG-seropositive, 11.76% were AQP4-IgG-seropositive, and 30.88% samples were double seronegative. Other causes included multiple sclerosis (n = 4), lactational ON (n = 4), tuberculosis (n = 2), invasive perineuritis (n = 2), COVID-19 vaccination (n = 2), and COVID-19 (n = 1). The mean presenting best corrected visual acuity (BCVA) was 1.31 ± 1.16 logMAR (logarithm of the minimum angle of resolution). The mean BCVA at 3 months was 0.167 ± 0.46 logMAR. Only initial VA ≤ 'Counting fingers' (CF) had a significant association with the visual outcome for final VA worse than CF. The steep cost of investigations and treatment posed challenges for many patients in the management of ON. CONCLUSION: MOG-IgG-associated ON is common in India. Unfortunately, financial constraints delay the diagnosis and timely management of ON, adversely affecting the outcome.

Effectiveness of Robotics in Stroke Rehabilitation to Accelerate Upper Extremity Function: Systematic Review.

Objective: To examine the effectiveness of robot-assisted therapy (RAT) combined with conventional therapy (CT) compared to CT alone in accelerating upper extremity (UE) recovery poststroke. Data Sources. We searched five databases: Ovid, MEDLINE, CINAHL, PubMed, and Scopus Study Selection. Studies were selected for this review using the following inclusion criteria: randomized controlled trials of adults, RAT combined with CT compared to CT, and Fugl-Meyer Assessment (FMA) as an outcome measure. Studies focused on children with neurological impairments, and studies that used RAT to facilitate lower extremity recovery and/or improve gait were excluded. Data Extraction. The initial search yielded 3,019 citations of articles published between January 2011 and May 2021. Fourteen articles met the inclusion criteria. Randomization, allocation sequence concealment, blinding, and other biases were assessed. Data Synthesis. Current evidence suggests that the use of RAT along with CT may accelerate upper extremity recovery, measured by FMA, in the beginning of rehabilitation. However, the progress fades over time. More empirical research is needed to validate this observation. Also, the findings related to cost-benefit analyses of RAT are inconclusive. Conclusions: It is unclear whether RAT accelerates UE recovery poststroke when used in conjunction with conventional therapy. Given the capital and maintenance costs involved in developing and delivering RAT, more controlled studies examining the effectiveness and cost-benefit analysis of RAT are needed before it can be used widely. This trial is registered with CRD42021270824.

Assessment of haemodynamic response to tracheal intubation and prone positioning following clonidine and enalaprilat in lumbar spine surgeries: A double blind randomised controlled trial.

Background and Aim: This study evaluates the effectiveness of long-acting antihypertensive drugs (clonidine and enalaprilat) in blunting the intubation response. Also, the study seeks to determine how effectively clonidine and enalaprilat can maintain stable haemodynamics during a change in position. Methods: After ethical committee approval and trial registration, a double-blinded, randomised controlled trial was conducted with 71 consenting patients scheduled for elective spine surgery in a prone position under general anaesthesia. Group C received clonidine 2 µg/kg, and Group E received enalaprilat 1.25 mg diluted in normal saline as an intravenous infusion given over 10 min before induction of anaesthesia. The changes in heart rate (HR) and blood pressure (BP) in response to the infusion of the study drugs, induction, tracheal intubation and change in position were recorded. P value <0.05 was considered significant. Statistical analysis was performed using Statistical Package for the Social Sciences (SPSS) version 25. Results: Clonidine infusion caused a significant fall in heart rate post-infusion and post-induction with propofol (p value <0.05). Both clonidine and enalaprilat caused a significant fall in mean arterial pressure (MAP) post-infusion and post-induction (p value <0.05). Clonidine effectively blunted the intubation response with no increase in HR and MAP following intubation. Enalaprilat caused a significant rise in HR in response to intubation. On proning, there was a significant fall in MAP in both groups. Conclusion: Clonidine is effective in blunting the intubation response. Preoperative infusion of clonidine and enalaprilat causes hypotension during a change of position.

Increasing the survival and efficacy of entomopathogenic nematodes on exposed surfaces by Pickering emulsion formulations offers new venue for foliar pest management.

Formulation technology has been the primordial focus to improve the low viability and erratic infectivity of entomopathogenic nematodes (EPNs) for foliar application. Adaptability to the fluctuating environment is a key trait in ensuring the survival and efficacy of EPNs. Hence, tailoring formulations towards EPNs foliar applications would effectively deliver consistent and reliable results for above-ground applications. EPNs survival and activity were characterized in novel Pickering emulsion post-application in planta cotton foliage. Two different types of novel formulations, Titanium Pickering emulsion (TPE) and Silica Pickering emulsion Gel (SPEG), were tailored for EPNs foliar applications. We report an extension of survival and infectivity to 96 hrs under controlled conditions by SPEG formulations for survival of IJ's on cotton foliage. In addition, survival of IJs (LT50) was extended from 14hrs in water to > 80 hrs and > 40 hrs by SPEG and TPE respectively. SPEG accounted for the slowest decrease of live IJs per surface area in comparison to TPE and control samples over time, exhibiting a 6-fold increase at 48 hrs. Under extreme conditions, survival and efficacy were extended for 8hrs in SPEG compared to merely 2hrs in control. Potential implications and possible mechanisms of protection are discussed.

The Global Status of Occupational Therapy Workforce Research Worldwide: A Scoping Review.

IMPORTANCE: To fulfill their societal role, occupational therapists need to exist in sufficient supply, be equitably distributed, and meet competency standards. Occupational therapy workforce research is instrumental in reaching these aims, but its global status is unknown. OBJECTIVE: To map the volume and nature (topics, methods, geography, funding) of occupational therapy workforce research worldwide. DATA SOURCES: Six scientific databases (MEDLINE/PubMed, Scopus, CINAHL, Web of Science Core Collection, PDQ-Evidence for Informed Health Policymaking, OTseeker), institutional websites, snowballing, and key informants. STUDY SELECTION AND DATA COLLECTION: Research articles of any kind were included if they involved data regarding occupational therapists and addressed 1 of 10 predefined workforce research categories. Two reviewers were used throughout study selection. No language or time restrictions applied, but the synthesis excluded publications before 1996. A linear regression examined the publications' yearly growth. FINDINGS: Seventy-eight studies met the inclusion criteria, 57 of which had been published since 1996. Although significant (p < .01), annual publication growth was weak (0.07 publications/yr). "Attractiveness and retention" was a common topic (27%), and cross-sectional surveys were frequent study designs (53%). Few studies used inferential statistics (39%), focused on resource-poor countries (11%), used standardized instruments (10%), or tested a hypothesis (2%). Only 30% reported funding; these studies had stronger methodology: 65% used inferential statistics, and just 6% used exploratory cross-sectional surveys. CONCLUSIONS AND RELEVANCE: Worldwide occupational therapy workforce research is scant and inequitably distributed, uses suboptimal methods, and is underfunded. Funded studies used stronger methods. Concerted efforts are needed to strengthen occupational therapy workforce research. What This Article Adds: This review highlights the opportunity to develop a stronger, evidence-based strategy for workforce development and professional advocacy.

A Comparison Between the Effects of Single-Dose Oral Gabapentin and Oral Clonidine on Hemodynamic Parameters in Laparoscopic Surgeries: A Randomized Controlled Trial.

Background and objective Laparoscopic surgeries can result in exaggerated sympathetic responses due to pneumoperitoneum. Many drugs including clonidine and gabapentin have been evaluated to attenuate the hemodynamic response to abdominal insufflation. In light of this, this study was conducted to compare the effects of preoperative administration of oral gabapentin with those of clonidine on intraoperative hemodynamic parameters in patients undergoing laparoscopic surgeries. Methodology A prospective, randomized, double-blinded comparative trial spanning a period of one year was conducted involving 150 patients scheduled to undergo elective laparoscopic surgeries at a tertiary hospital. Patients who fulfilled the inclusion criteria were randomly allocated into three groups: to receive oral gabapentin 300 mg (Group G) or oral clonidine 150 mcg (Group CL) or a placebo tablet (Group C). Standard anesthetic protocols were followed during the surgery and the mean arterial pressure (MAP), heart rate (HR), postoperative pain as assessed by visual analog scale (VAS) scores, postoperative analgesic consumption, sedation scores, and complications like nausea, vomiting, and dry mouth were recorded and analyzed. Results HR and MAP were significantly reduced in the intervention groups (clonidine and gabapentin) compared to the control group. There was a statistically significant reduction in MAP and HR in patients on oral clonidine compared to patients on gabapentin. Postoperative pain as assessed by VAS score was better in the intervention groups compared to patients who were administered a placebo. Postoperative analgesic consumption was significantly lower in patients on clonidine and gabapentin compared to the control group. Patients on oral gabapentin received lower doses of tramadol compared to patients on clonidine. Postoperative sedation as assessed by the Ramsay sedation scale (RSS) score was higher in patients on oral gabapentin. Complications like postoperative nausea and vomiting were significantly reduced in the intervention groups, while dryness of mouth was more prevalent in patients on clonidine. Conclusion Based on our findings, oral clonidine is more effective in attenuating hemodynamic response to pneumoperitoneum compared to oral gabapentin. Postoperative pain was lower in intervention groups compared to the control group. However, patients on gabapentin required a lower dose of analgesics postoperatively compared to patients on clonidine. Postoperative sedation was also more pronounced in patients on gabapentin while dryness of mouth was more common in patients on oral clonidine.

A green formulation for superhydrophobic coatings based on Pickering emulsion templating for anti-biofilm applications.

This study reports significant steps toward developing anti-biofilm surfaces based on superhydrophobic properties that meet the complex demands of today's food and medical regulations. It presents inverse Pickering emulsions of water in dimethyl carbonate (DMC) stabilized by hydrophobic silica (R202) as a possible food-grade coating formulation and describes its significant passive anti-biofilm properties. The final coatings are formed by applying the emulsions on the target surface, followed by evaporation to form a rough layer. Analysis shows that the final coatings exhibited a Contact Angle (CA) of up to 155° and a Roll-off Angle (RA) lower than 1° on the polypropylene (PP) surface, along with a relatively high light transition. Dissolving polycaprolactone (PCL) into the continuous phase enhanced the average CA and coating uniformity but hindered the anti-biofilm activity and light transmission. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed a uniform coating by a "Swiss-cheese" like structure with high nanoscale and microscale roughness. Biofilm experiments confirm the coating's anti-biofilm abilities that led to the reduction in survival rates of S.aureus and E.coli, by 90-95% respectively, compared to uncoated PP surfaces.

A Novel Platform for Root Protection Applies New Root-Coating Technologies to Mitigate Soil-Borne Tomato Brown Rugose Fruit Virus Disease.

Tomato brown rugose fruit virus (ToBRFV) is a soil-borne virus showing a low percentage of ca. 3% soil-mediated infection when the soil contains root debris from a previous 30-50 day growth cycle of ToBRFV-infected tomato plants. We designed stringent conditions of soil-mediated ToBRFV infection by increasing the length of the pre-growth cycle to 90-120 days, adding a ToBRFV inoculum as well as truncating seedling roots, which increased seedling susceptibility to ToBRFV infection. These rigorous conditions were employed to challenge the efficiency of four innovative root-coating technologies in mitigating soil-mediated ToBRFV infection while avoiding any phytotoxic effect. We tested four different formulations, which were prepared with or without the addition of various virus disinfectants. We found that under conditions of 100% soil-mediated ToBRFV infection of uncoated positive control plants, root-coating with formulations based on methylcellulose (MC), polyvinyl alcohol (PVA), silica Pickering emulsion and super-absorbent polymer (SAP) that were prepared with the disinfectant chlorinated-trisodium phosphate (Cl-TSP) showed low percentages of soil-mediated ToBRFV infection of 0%, 4.3%, 5.5% and 0%, respectively. These formulations had no adverse effect on plant growth parameters when compared to negative control plants grown under non ToBRFV inoculation conditions.

Factors Influencing the Time of Intubation Using C-MAC D-Blade® Video Laryngoscope: An Observational Cross-Sectional Study.

Purpose C-MAC D-Blade® (Karl Storz, Tuttlingen, Germany) video laryngoscope (VL) has proved to be of immense utility in difficult intubation. But unfortunately, in an urgent situation, the predictable correct curvature of the endotracheal tube for effortless intubation is not met. We hypothesized that expertise is the most important variable in intubation and that novice students will be unable to intubate if the angle of curvature is incorrect. Methods An observational cross-sectional study was planned with 30 anesthesia residents, categorized into three groups based on their expertise in laryngoscopy. Students had to intubate an airway mannequin using the C-MAC D-Blade® VL with three different stylet angulations. The curvatures were 80, 100, and 120 degrees, which are commonly encountered in routine day-to-day practice. The time to get a stable glottic view, time to intubate, and ease of intubation were measured. Results The mean time to intubate was the least with 100-degree angulation in group C (19.60 ± 0.97) while the maximum time was in group A with 80-degree angulation (61.49 ± 3.69). A significant difference was noted in time to get a stable glottic view when compared between the groups. There was no difference in time to intubate with different stylet angulations when compared between groups. Conclusions Novices and experts could intubate even if the angle of curvature was incorrect taking more time. The time to laryngoscopy is significantly dependent on experience, but the time to intubate is influenced by the angle of curvature of the stylet.

Situational analysis for informing the global strengthening of the occupational therapy workforce.

BACKGROUND: Occupational Therapists are needed for meeting the health, rehabilitation, and occupational needs of the population worldwide, but there is no strategy for strengthening the occupational therapy workforce against a backdrop of an insufficient and inequitable supply worldwide. OBJECTIVE: To perform a situational assessment of occupational therapy workforce development and research toward informing a global human resources strategy for the occupational therapy workforce strengthening. METHOD: A multi-methods design incorporating Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis based on scoping review findings, workforce development frameworks, and expert feedback. RESULTS: Strengths included identified workforce research trends, gaps, and findings. Weaknesses included a shortage of workforce research, lack of uniform and readily available workforce datasets, absence of workforce research programs, over-reliance on descriptive and non-experimental research, lack of research on workforce topics (e.g., diversity), and lack of labor market or economic analyses. Opportunities are the availability of guidance and tools for strengthening the health and rehabilitation workforce worldwide, and increased membership from low- and middle-income countries (LMICs) in the World Federation of Occupational Therapists. Threats include the suboptimal funding of occupational therapy workforce research, the lack of occupational therapists data on international datasets and studies, suboptimal educational capacity in LMICs, lack of professional regulation and uniform workforce data collection in many contexts, and a perceived lower priority of this health workforce focused on health and wellbeing rather than medical outcomes. CONCLUSION: This SWOT analysis identifies strengths and opportunities to be seized and weaknesses and threats to be addressed by development of a strategy for the global strengthening of the occupational therapy workforce.

Tolerance of Steinernema carpocapsae infective juveniles in novel nanoparticle formulations to ultraviolet radiation.

Entomopathogenic nematodes (EPNs) are susceptible to abiotic environmental factors including ultraviolet (UV) radiation, which affects the survival and efficacy. This study evaluated nanoparticle (NP) formulations for protecting Steinernema carpocapsae infective juveniles (IJs) from UV radiation. First, silica-NH2 NPs at oil-to-water ratios of 2:8, 3:7 and 4:6 were compared with Barricade Fire Gel (1 % and 2 %) and a water control (aqueous IJs) by exposing IJs to UV light (254 nm) for 0, 10 and 20 min. Barricade gel (especially 2 % Barricade) significantly improved IJs viability after UV treatment, while all three NPs had adverse effects on IJ viability after UV radiation. Subsequently, two silica (SiO2 basic and advanced) and one titania (TiO2) based formulations were tested with Barricade (1 % and 2 %) and a water control. The titania-NH2 NPs provided the highest UV protection, and IJ viability and virulence were not reduced even after 20-min UV. Except TiO2, only 2 % Barricade at 10-min UV and SiO2 basic at 20-min UV had lower IJ mortality than the water control. Only TiO2 formulated IJs caused higher insect mortality and infection levels than aqueous IJs after UV treatment. The UV tolerance of TiO2 was further examined by assessing the number of nematodes invading the hosts. Consistent with virulence tests, the number of invading nematodes in titania-NH2 NPs did not decrease after UV radiation for 10 or 20 min compared with the no-UV control. The anti-UV capability of titania-NH2 NPs has promise as a tool to enhance biocontrol efficacy of EPNs under field conditions.

Phytocannabinoids Act Synergistically with Non-Steroidal Anti-Inflammatory Drugs Reducing Inflammation in 2D and 3D In Vitro Models.

Lung inflammation is associated with elevated pro-inflammatory cytokines and chemokines. Treatment with FCBD:std (standard mix of cannabidiol [CBD], cannabigerol [CBG] and tetrahydrocannabivarin [THCV]) leads to a marked reduction in the inflammation of alveolar epithelial cells, but not in macrophages. In the present study, the combined anti-inflammatory effect of FCBD:std with two corticosteroids (dexamethasone and budesonide) and two non-steroidal anti-inflammatory drugs (NSAID; ibuprofen and diclofenac), was examined. Enzyme-linked immunosorbent assay (ELISA) was used to determine protein levels. Gene expression was determined by quantitative real-time PCR. Inhibition of cyclo-oxygenase (COX) activity was determined in vitro. FCBD:std and diclofenac act synergistically, reducing IL-8 levels in macrophages and lung epithelial cells. FCBD:std plus diclofenac also reduced IL-6, IL-8 and CCL2 expression levels in co-cultures of macrophages and lung epithelial cells, in 2D and 3D models. Treatment by FCBD:std and/or NSAID reduced COX-1 and COX-2 gene expression but not their enzymatic activity. FCBD:std and diclofenac exhibit synergistic anti-inflammatory effects on macrophages and lung epithelial cells, yet this combined activity needs to be examined in pre-clinical studies and clinical trials.

Quality of Occupational Therapy Research in India - A Descriptive Review.

Background: Occupational therapy (OT) enhances functional independence in the daily activities of people with disabilities and subsequently their quality of life. Research in OT generates evidence to provide safe and effective services to the disabled. However, OT research in India has been shown to have various methodological limitations. These methodological limitations are expected to impact the quality of OT research as well as the evidence derived from this research to inform decision-making in rehabilitation. The majority of the OT research is disseminated and promoted through the All India Occupational Therapists' Association's (AIOTA) annual national conference (ANC). Analyzing the abstracts, selected for the presentation at the ANC could help understand and strategically improve the quality of OT research in India. Objectives: To explore and describe the quality of OT research in India. Study Design: Descriptive analysis. Methods: Descriptive, nonsystematic review and analysis of the key methodological aspects of the conference abstracts submitted for the AIOTA ANC published in the Indian Journal of OT (IJOT) from 2017 to 2021 was carried out. Information related to the methodological aspects of the research abstracts was extracted using a data extraction form and the data were synthesized and reported descriptively. Results: About 218 abstracts had been selected for either poster or oral presentations in the AIOTA ANC. All the abstracts were included for the review. A total of 8055 participants were recruited for the studies conducted from 2017 to 2021. About 5757 (72%) of the participants were recruited for cross-sectional studies. Nearly 72 (33%) of the abstracts presented were related to cross-sectional studies, 52 (24%) were case studies and 66 (30%) were experimental studies. However, research designs implying highest level of evidence such as systematic reviews were only 4 (2%) and randomized controlled trials were only 9 (4%) with 297 participants. Notably, 203 (98%) of the all the studies evaluating effectiveness of interventions or aiming to investigate associations reported positive results with statistically significant improvements and associations. Conclusion: The review provides invaluable information related to the quality of OT research in India. It implies the need to improve the scientific rigor of the evidence generated in relation to OT research in India. This review also implies the need for a radical change and strengthening of OT research within OT education and professional practice in India. National and global OT associations need to prioritize good quality OT research by enhancing the research skills and competencies of OTs in India. This could help promote evidence-based OT science and develop the OT profession in the world's second-most populous country. In addition, it is also expected to encourage those OT researchers who have been striving to build OT research standards in India.

Individual Coating of Entomopathogenic Nematodes with Titania (TiO2) Nanoparticles Based on Oil-in-Water Pickering Emulsion: A New Formulation for Biopesticides.

This study presents a new eco-friendly formulation of entomopathogenic nematodes (EPNs) based on individual coating of EPNs with titanium dioxide (TiO2) nanoparticles (NPs) and mineral oil via oil-in-water Pickering emulsions. Mineral oil-in-water emulsions stabilized by amine-functionalized titanium dioxide (TiO2-NH2) particles were prepared. 40:60 and 50:50 oil-water volume ratios using 2 wt % TiO2-NH2 particles were found to be the most stable emulsions with a droplet size suitable for the formulation and were further studied for their toxicity against the incorporated EPNs. Carboxyfluorescein was covalently bonded to TiO2-NH2 NPs, and the resulting composite was observed via fluorescence confocal microscopy. The dry coating was evaluated using SEM and confocal microscopy, which showed significant nematode coverage by the particles and oil. The final formulation was biocompatible with the studied EPNs, where the viability of the EPNs in the formulation was equivalent to control aqueous suspension after 120 days. Finally, yields of nematodes from infected Galleria mellonella cadavers collected for 150 days showed no significant differences (P > 0.05) using the tested emulsions compared to the control containing nematodes in water.

Exploring the Research Priorities for Occupational Therapy in India: A Descriptive Review.

Background: Occupational therapists are considered an important workforce for the rehabilitation of persons with disabilities globally. However, in India, the profession is just beginning to gain recognition within the national and state-level systems for health care. One of the reasons for this could be the paucity of specific research related to the development of occupational therapy (OT) and its benefits to the health systems. Therefore, it is of immense public health importance to explore the priorities and gaps in OT research in India. A vast majority of the OT research in India is promoted and disseminated through the All-India Occupational Therapists Association (AIOTA) and its annual national conference (ANC). Objectives: The objective of this study is to descriptively review the conference abstracts of the AIOTA ANC published in the Indian Journal of OT (IJOT), an official publication of the AIOTA, from 2017 to 2021. Study Design: The study design was a descriptive, nonsystematic review. Methods: Review of the abstracts selected for the AIOTA ANC published in the IJOT from 2017 to 2021. A data extraction form was developed and used to synthesize data related to the clinical and demographic characteristics of OT research in India. Results: The search yielded 218 abstracts. State-level trends indicated that close to 85% of the research submissions were from four states and no submissions from the northeastern states until 2020. Nearly 60% of the abstracts were clinical research with OT interventions. About 40% of these research abstracts were related to pediatrics, followed by neurology (17%), musculoskeletal (15%), mental health (10%), and ergonomics and assistive technology (8%). There were 1%-2% of research abstracts submitted related to coronavirus disease-2019 (COVID-19) and geriatrics. About 85% of the research abstracts were related to impairment (39%), activity limitation (26%), and social participation (22%). Conclusion: This review highlights the need for diversifying the research in OT in India. This is particularly important in relation to expanding from selected states to pan-India research and development, especially in the northeastern states. Furthermore, the focus of OT research must move beyond impairments and approach disability from the biopsychosocial perspective. It is also very important to diversify the research in OT to areas that are of public health importance such as COVID-19, geriatrics, noncommunicable diseases, and rehabilitation in health systems. Priority setting for research in OT in India is an important implication of this review.

Enzymatic basis of the Fc-selective intra-chain disulfide reduction and free thiol content variability in an antibody produced in Escherichia coli.

BACKGROUND: Escherichia coli (E. coli) is a promising host for production of recombinant proteins (including antibodies and antibody fragments) that don't require complex post-translational modifications such as glycosylation. During manufacturing-scale production of a one-armed antibody in E. coli (periplasmic production), variability in the degree of reduction of the antibody's disulfide bonds was observed. This resulted in variability in the free thiol content, a potential critical product quality attribute. This work was initiated to understand and prevent the variability in the total free thiol content during manufacturing. RESULTS: In this study, we found that the reduction in antibody's disulfide bonds was observed to occur during homogenization and the ensuing homogenate hold step where in the antibody is exposed to redox enzymes and small molecule reductants present in homogenate. Variability in the downstream processing time between the start of homogenization and end of the homogenate hold step resulted in variability in the degree of antibody disulfide bond reduction and free thiol content. The disulfide bond reduction in the homogenate is catalyzed by the enzyme disulfide bond isomerase C (DsbC) and is highly site-specific and occurred predominantly in the intra-chain disulfide bonds present in the Fc CH2 region. Our results also imply that lack of glycans in E. coli produced antibodies may facilitate DsbC accessibility to the disulfide bond in the Fc CH2 region, resulting in its reduction. CONCLUSIONS: During E. coli antibody manufacturing processes, downstream processing steps such as homogenization and subsequent processing of the homogenate can impact degree of disulfide bond reduction in the antibody and consequently product quality attributes such as total free thiol content. Duration of the homogenate hold step should be minimized as much as possible to prevent disulfide bond reduction and free thiol formation. Other approaches such as reducing homogenate temperature, adding flocculants prior to homogenization, using enzyme inhibitors, or modulating redox environments in the homogenate should be considered to prevent antibody disulfide bond reduction during homogenization and homogenate processing steps in E. coli antibody manufacturing processes.

Platform for Active Vaccine Formulation Using a Two-Mode Enhancement Mechanism of Epitope Presentation by Pickering Emulsion.

The efficiency of epitope-based vaccination (subunit vaccines) is tightly correlated with heterogeneity and the high density of epitope presentation, which maximizes the potential antigenic determinants. Here, we developed a two-mode platform for intensifying the epitope presentation of subunit vaccines. The two-mode epitope presentation enhancement includes a covalent attachment of high concentrations of SARS-CoV-2-S1 peptide epitope to the surface of virus-like-particles (VLPs) and the subsequent assembly of VLP/epitope conjugates on the oil droplet surface at an oil/water interface of an emulsion as Pickering stabilizers. The resultant emulsions were stable for weeks in ambient conditions, and our platform was challenged using the epitope of the SARS-CoV-2-S1 peptide that served as a model epitope in this study. In vivo assays showed that the αSARS-CoV-2-S1 immunoglobulin G (IgG) titers of the studied mouse antisera, developed against the SARS-CoV-2-S1 peptide under different epitope preparation conditions, showed an order of magnitude higher IgG titers in the studied VLP-based emulsions than epitopes dissolved in water and epitopes administered with an adjuvant, thereby confirming the efficacy of the formulation. This VLP-based Pickering emulsion platform is a fully synthetic approach that can be readily applied for vaccine development to a wide range of pathogens.