Biomedical applications of nanomaterials in the advancement of nucleic acid therapy: Mechanistic challenges, delivery strategies, and therapeutic applications

In the past few decades, substantial advancement has been made in nucleic acid (NA)-based therapies. Promising treatments include mRNA, siRNA, miRNA, and anti-sense DNA for treating various clinical disorders by modifying the expression of DNA or RNA. However, their effectiveness is limited due to their concentrated negative charge, instability, large size, and host barriers, which make widespread application difficult. The effective delivery of these medicines requires safe vectors that are efficient & selective while having non-pathogenic qualities; thus, nanomaterials have become an attractive option with promising possibilities despite some potential setbacks. Nanomaterials possess ideal characteristics, allowing them to be tuned into functional bio-entity capable of targeted delivery. In this review, current breakthroughs in the non-viral strategy of delivering NAs are discussed with the goal of overcoming challenges that would otherwise be experienced by therapeutics. It offers insight into a wide variety of existing NA-based therapeutic modalities and techniques. In addition to this, it provides a rationale for the use of non-viral vectors and a variety of nanomaterials to accomplish efficient gene therapy. Further, it discusses the potential for biomedical application of nanomaterials-based gene therapy in various conditions, such as cancer therapy, tissue engineering, neurological disorders, and infections.

Preclinical study models of psoriasis: State-of-the-art techniques for testing pharmaceutical products in animal and nonanimal models

Local and systemic treatments exist for psoriasis, but none can do more than control its symptoms because of its numerous unknown mechanisms. The lack of validated testing models or a defined psoriatic phenotypic profile hinders antipsoriatic drug development. Despite their intricacy, immune-mediated diseases have no improved and precise treatment. The treatment actions may now be predicted for psoriasis and other chronic hyperproliferative skin illnesses using animal models. Their findings confirmed that a psoriasis animal model could mimic a few disease conditions. However, their ethical approval concerns and inability to resemble human psoriasis rightly offer to look for more alternatives. Hence, in this article, we have reported various cutting-edge techniques for the preclinical testing of pharmaceutical products for the treatment of psoriasis.

The burden of COVID-19 infection in a rural Tamil Nadu community

Background

There have been over 30 million cases of COVID-19 in India and over 430,000 deaths. Transmission rates vary from region to region, and are influenced by many factors including population susceptibility, travel and uptake of preventive measures. To date there have been relatively few studies examining the impact of the pandemic in lower income, rural regions of India. We report on a study examining COVID-19 burden in a rural community in Tamil Nadu.

Methods

The study was undertaken in a population of approximately 130,000 people, served by the Rural Unit of Health and Social Affairs (RUHSA), a community health center of CMC, Vellore. We established and evaluated a COVID-19 PCR-testing programme for symptomatic patients—testing was offered to 350 individuals, and household members of test-positive cases were offered antibody testing. We also undertook two COVID-19 seroprevalence surveys in the same community, amongst 701 randomly-selected individuals.

Results

There were 182 positive tests in the symptomatic population (52.0%). Factors associated with test-positivity were older age, male gender, higher socioeconomic status (SES, as determined by occupation, education and housing), a history of diabetes, contact with a confirmed/suspected case and attending a gathering (such as a religious ceremony, festival or extended family gathering). Amongst test-positive cases, 3 (1.6%) died and 16 (8.8%) suffered a severe illness. Amongst 129 household contacts 40 (31.0%) tested positive. The two seroprevalence surveys showed positivity rates of 2.2% (July/Aug 2020) and 22.0% (Nov 2020). 40 tested positive (31.0%, 95% CI: 23.02 − 38.98). Our estimated infection-to-case ratio was 31.7.

Conclusions

A simple approach using community health workers and a community-based testing clinic can readily identify significant numbers of COVID-19 infections in Indian rural population. There appear, however, to be low rates of death and severe illness, although vulnerable groups may be under-represented in our sample. It’s vital these lower income, rural populations aren’t overlooked in ongoing pandemic monitoring and vaccine roll-out in India.

COVID-19: clinical presentation and detection methods

The unending outburst of COVID-19 has reinforced the necessity of SARS-CoV-2 identification approaches for the prevention of infection transmission and the proper care of severe and critical patients. As there is no cure, a prompt and reliable diagnosis of SARS-CoV2 is vital to counter the spread and to provide adequate care and treatment for the infection. Currently, RT-PCR is a gold standard detection method for the qualitative and quantitative detection of viral nucleic acids. Besides, enzyme-linked immunosorbent assay is also a primarily used method for qualitative estimation of viral load. However, almost all the detection methods have their pros and cons in terms of specificity, accuracy, sensitivity, cost, time consumption, the need for sophisticated laboratories, and the requirement of skilled technical experts to carry out the detection tests. Thus, it is suggested to integrate different techniques to enhance the detection efficiency and accurateness for SARS-CoV2. This review focuses on preliminary, pre-confirmatory, and confirmatory methods of detection such as imaging techniques (chest-X-ray and chest- computed tomography), nucleic acid detection methods, serological assay methods, and viral culture and identification methods that are currently being employed to detect the presence of SARS-CoV-2 infection along with recent detection method and applicability for COVID-19.

Lipid A adjuvanted Chylomicron Mimicking Solid Fat Nanoemulsions for Immunization Against Hepatitis B

Traditional parenteral recombinant hepatitis B virus (HBV) vaccines have effectively reduced the disease burden despite being able to induce seroprotective antibody titers in 5-10% vaccinated individuals (non-responders). Moreover, an estimated 340 million chronic HBV cases are in need of treatment. Development of safe, stable, and more effective hepatitis B vaccine formulation would address these challenges. Recombinant hepatitis B surface antigen (rHBsAg) entrapped solid fat nanoemulsions (SFNs) containing monophosphoryl lipid A (MPLA) that was prepared and optimized by quality by design (QbD) using response surface methodology (RSM), i.e., central composite design (CCD). Its immune potential was evaluated with preset immunization protocol in a murine model. Dose escalation study revealed that formulation containing 1 μg of rHBsAg entrapped SFNs with MPLA-induced significant higher humoral, and cellular response compared to the marketed vaccine (Genvac B) administered intramuscularly. SFNs with nanometric morphology and structural similarity with chylomicrons assist in improved uptake and processing to lymphatics. Moreover, the presence of an immunogenic component in its structure further augments delivery of rHBsAg to immune cells with induction of danger signals. This multi-adjuvant based approach explores new prospect for the dose sparing. Improved cellular immune response induced by this vaccine formulation suggests that it could be tested as an immunotherapeutic vaccine as well.

Development of Adjuvanted Solid Fat Nanoemulsions for Pulmonary Hepatitis B Vaccination

Pulmonary vaccination is one of the most promising routes for immunization owing to its noninvasive nature and induction of strong mucosal immunity and systemic response. In the present study, recombinant hepatitis B surface antigen loaded solid fat nanoemulsions (SFNs) as carrier system and monophosphoryl lipid A as an adjuvant-carrier system was prepared and evaluated as multiadjuvanted vaccine system for deep pulmonary vaccination. Deposition and clearance from the deep lung of rats were determined by gamma scintigraphy. Biodistribution of SFNs was determined by the live animal imaging system. SFNs dispersion showed slower clearance as compared with sodium pertechnetate control solution (^∗∗∗p <0.001) from the pulmonary region due to the virtue of particulate and hydrophobic nature of formulations. Humoral (sIgA and IgG) and cellular (IL-2 and IF-γ) immune responses were found to be significant (^∗∗∗p <0.001) when compared with naïve antigen (recombinant surface antigen without any excipient) solution. Data indicate that deep pulmonary immunization offers a stronger immune response with balanced humoral, mucosal, and cellular immunization, which further needs to be tested in higher animals to support this hypothesis for clinical translation of this so far neglected yet potential target tissue for immunization.

Nanoparticulate mediated transcutaneous immunization: Myth or reality

Transcutaneous immunization (TCI) is a promising route of vaccine delivery through skin due to many well documented advantages. The main obstacle in TCI is the skin's top dead layer i.e. stratum corneum which is difficult to penetrate. Efficiently delivery of antigen to the immune competent cells of epidermis or dermis in TCI might elicit an effective immune response. In this review, skin immunology with a particular focus on potential of immunological active receptors in influencing adaptive immune responses is highlighted. The challenges with TCI and methods to improve it using different adjuvants, chemical and physical approaches, delivery systems, and combination of above methods to further improve immune response following skin application of antigen are elaborately discussed. Nanoparticulate vaccine delivery systems with reference to their applications in TCI are classified according to their chronological development. Conclusively, clinical translations of above methods are also briefly reviewed.

FROM THE CLINICAL EDITOR

Transcutaneous immunization has been investigated by many as a promising route of vaccination. In this comprehensive review article, the authors described and discussed the existing knowledge and difficulties in this approach. Furthermore, ways of improving transcutaneous delivery were also reviewed.

Proteins and peptides: The need to improve them as promising therapeutics for ulcerative colitis

The present review briefly describes the nature, type and pathogenesis of ulcerative colitis, and explores the potential use of peptides and proteins in the treatment of inflammatory bowel disease, especially ulcerative colitis. Intestinal absorption and the barrier mechanism of peptide and protein drugs are also discussed, with special emphasis on various strategies which make these drugs better therapeutics having high specificity, potency and molecular targeting ability. However, the limitation of such therapeutics are oral administration, poor pharmacokinetic profile and decreased bioavailability. The recent findings illustrated in this review will be helpful in designing the peptide/protein drugs as a promising treatment of choice for ulcerative colitis.

Incidence of Haemophilus influenzae type b meningitis in India

BACKGROUND & OBJECTIVE

Vaccine policy depends on locally relevant disease burden estimates. The incidence of Haemophilus influenzae type b (Hib) disease is not well characterized in the South Asian region, home to 30 per cent of the world's children. There are limited data from prospective population incidence studies of Hib in Asia, and no data available from India. We therefore carried out this study to assess the burden of Hib meningitis in India.

METHODS

A prospective surveillance study was carried out during 1997 and 1999 in hospitals for cases of Hib meningitis from 5 administrative areas of an Indian district (Vellore, Tamil Nadu) with 56,153 children under 5 yr of age, over a 24 month period

RESULTS

Ninety seven cases of possible meningitis (> 10 WBC/microl in CSF) were reported, an annual incidence of 86 per 100,000 (95%CI 69 to 109) in 0-4 yr old children, and 357 per 100,000 in 0-11 month infants. Eighteen had proven bacterial meningitis, an annual incidence of 15.9 per 100,000. Eight CSF had Hib by culture or antigen testing, an annual incidence of 7.1 per 100,000 (95%CI 3.1 to 14.0) in children 0-59 months. In infants 0-11 months of age, the incidence of Hib meningitis was 32 per 100,000 (95%CI 16 to 67) and in the 0-23 month group it was 19 (95%CI 8 to 37).

INTERPRETATION & CONCLUSION

Our data are the first minimal estimate of the incidence of Hib meningitis for Indian children. The observed incidence data are similar to European reports before Hib vaccine use, suggest substantial disease before 24 months of age, and provide data useful for policy regarding Hib immunization.

Rates and factors associated with suicide in Kaniyambadi Block, Tamil Nadu, South India, 2000-2002

BACKGROUND

Inefficient civil registration systems, non-report of deaths, variable standards in certifying death and the legal and social consequences of suicide are major obstacles to investigating suicide in the developing world.

OBJECTIVE

The aim of this study was to prospectively determine the suicide rate in Kaniyambadi Block, Tamil Nadu, South India, for the years 2000-2002 using verbal autopsies.

METHOD

The setting for the study was a comprehensive community health programme in a development block in rural South India. The main outcome measure was death by suicide, diagnosed by a detailed verbal autopsy and census, and birth and death data to identify the population base.

RESULTS

The average suicide rate was 92.1 per 100,000. The ratio of male to female suicides was 1:0.66. The age-specific suicide rate for men increased with age while that for women showed two peaks: 15-24 years and over 65 years of age. Hanging (49%) and poisoning with organo-phosphorus compounds (40.5%) were the commonest methods of committing suicide. Acute and/or chronic stress was elicited for nearly all subjects. More men suffered from chronic stress while more women had acute precipitating events (chi2 = 4.58; p < 0.04). People less than 44 years of age had more acute precipitating events before death while older subjects reported more chronic stress (chi2 = 17.38; p < 0.001).

CONCLUSION

The study replicates findings of an earlier study from the area. The suicide rate documented in this study is very high and is a major public health concern. There is a need for sentinel centres in India and in developing countries to monitor trends and to develop innovative strategies to reduce deaths by suicide.

Solid--cystic papillary tumor of pancreas

A case of Solid and Cystic Papillary Epithelial Tumor of Pancreas displaying low grade malignancy occurring in a 38 years old female is presented. It is a rare condition and could be diagnosed histopathologically after complete excision.

Prevalence of hepatitis B and hepatitis C virus coinfection in chronic liver disease

Coinfection with HBV and HCV may lead to serious consequences. The present study was done to find out the prevalence of coinfection in patients with chronic liver disease. From patients with hepatitis and chronic liver disease 1673 samples were received and analysed for HBsAg by ELISA. 1342 samples were analysed for anti HCV by third generation ELISA. 493 samples positive for HBsAg were also analysed for Anti HCV to see the prevalence of coinfection. 15(3.0%) were found positive for both HBsAg and anti HCV. Out of 15 patients with coinfection 4 (26.6%) had HCC. Prevalence of HCC in patients with coinfection was higher than either infection alone i.e. HBV-9.1% and HCV-16.5%.