Biopolymeric and lipid-based nanotechnological strategies for the design and development of novel mosquito repellent systems: recent advances.

Mosquitoes are the most medically important arthropod vectors of several human diseases. These diseases are known to severely incapacitate and debilitate millions of people, resulting in countless loss of lives. Over the years, several measures have been put in place to control the transmission of mosquito-borne diseases, one of which is using repellents. Repellents are one of the most effective personal protective measures against mosquito-borne diseases. However, conventional delivery systems of repellents (e.g., creams, gels, and sprays) are plagued with toxicity and short-term efficacy issues. The application of biopolymeric and lipid-based systems has been explored over the years to develop better delivery systems for active pharmaceutical ingredients including mosquito repellents. These delivery systems (e.g., solid lipid micro/nanoparticles, micro/nanoemulsions, or liposomes) possess desirable properties such as high biocompatibility, versatility, and controlled/sustained drug delivery, and thus are very important in tackling the clinical challenges of conventional repellent systems. Their capability for controlled/sustained drug release has improved patient compliance as it removes the need for consistent reapplication of repellents. They can also be engineered to reduce repellents' skin permeation, consequently improving their safety. However, despite the benefits that these systems offer very few of them have been successfully translated to the global market for commercial use, a vital challenge that previous reports have not thoroughly examined. The issue of limited clinical translation of novel repellent systems is a vital aspect to consider, as the ultimate goal is to move these systems from bench to bedside. As such, this study seeks to highlight the recent advances in the use of biopolymeric and lipid-based systems for the development of novel mosquito-repellent systems and also analyze the challenges that have limited the clinical translation of these systems while proposing possible strategies to overcome these challenges.

Endoplasmic reticulum stress in pancreatic ß-cell dysfunction: The potential therapeutic role of dietary flavonoids.

Diabetes mellitus (DM) is a global health burden that is characterized by the loss or dysfunction of pancreatic ß-cells. In pancreatic ß-cells, endoplasmic reticulum (ER) stress is a fact of life that contributes to ß-cell loss or dysfunction. Despite recent advances in research, the existing treatment approaches such as lifestyle modification and use of conventional therapeutics could not prevent the loss or dysfunction of pancreatic ß-cells to abrogate the disease progression. Therefore, targeting ER stress and the consequent unfolded protein response (UPR) in pancreatic ß-cells may be a potential therapeutic strategy for diabetes treatment. Dietary phytochemicals have therapeutic applications in human health owing to their broad spectrum of biochemical and pharmacological activities. Flavonoids, which are commonly obtained from fruits and vegetables worldwide, have shown promising prospects in alleviating ER stress. Dietary flavonoids including quercetin, kaempferol, myricetin, isorhamnetin, fisetin, icariin, apigenin, apigetrin, vitexin, baicalein, baicalin, nobiletin hesperidin, naringenin, epigallocatechin 3-O-gallate hesperidin (EGCG), tectorigenin, liquiritigenin, and acacetin have shown inhibitory effects on ER stress in pancreatic ß-cells. Dietary flavonoids modulate ER stress signaling components, chaperone proteins, transcription factors, oxidative stress, autophagy, apoptosis, and inflammatory responses to exert their pharmacological effects on pancreatic ß-cells ER stress. This review focuses on the role of dietary flavonoids as potential therapeutic adjuvants in preserving pancreatic ß-cells from ER stress. Highlights of the underlying mechanisms of action are also presented as well as possible strategies for clinical translation in the management of DM.

Design and evaluation of nanostructured lipid carrier of Bergenin isolated from Pentaclethra macrophylla for anti-inflammatory effect on lipopolysaccharide-induced inflammatory responses in macrophages.

Herein, we report the properties of nanostructured lipid carriers (NLCs) prepared with a gradient concentration of Bergenin (BGN) isolated from Pentaclethra macrophylla stem bark powder. A gradient concentration of BGN (BGN 0, 50, 100, 150, and 200 mg) was prepared in a 5 % lipid matrix consisting of Transcutol HP (75 %), Phospholipon 90H (15 %), and Gelucire 43/01 (10 %) to which a surfactant aqueous phase consisting of Tween 80, sorbitol, and sorbic acid was dissolved. The NLCs were evaluated by size, polydispersity index (PDI), zeta potential, Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), encapsulation efficiency, and in vitro drug release. The result shows polydispersed nanoparticles with high drug encapsulation (94.26-99.50 %). The nanoparticles were mostly spherical, but those from the 50 mg BGN batch were more cuboidal than spherical. The drug release was highest from the latter to the tune of 40 % compared to the pure BGN solution, which released about 15 % BGN. The anti-inflammatory activity of the BGN-NLC and total plant extract was studied on lipopolysaccharide (LPS)-inflamed macrophages. The cell study showed that BGN and plant extract had low cytotoxicity on macrophages and exhibited a dose-dependent anti-inflammatory effect on the LPS-induced inflammatory process in macrophages.

Nanoparticle-based delivery systems as emerging therapy in retinoblastoma: recent advances, challenges and prospects.

Retinoblastoma is the most common intraocular malignancy in children. The treatment of this rare disease is still challenging in developing countries due to delayed diagnosis. The current therapies comprise mainly surgery, radiotherapy and chemotherapy. The adverse effects of radiation and chemotherapeutic drugs have been reported to contribute to the high mortality rate and affect patients' quality of life. The systemic side effects resulting from the distribution of chemotherapeutic drugs to non-cancerous cells are enormous and have been recognized as one of the reasons why most potent anticancer compounds fail in clinical trials. Nanoparticulate delivery systems have the potential to revolutionize cancer treatment by offering targeted delivery, enhanced penetration and retention effects, increased bioavailability, and an improved toxicity profile. Notwithstanding the plethora of evidence on the beneficial effects of nanoparticles in retinoblastoma, the clinical translation of this carrier is yet to be given the needed attention. This paper reviews the current and emerging treatment options for retinoblastoma, with emphasis on recent investigations on the use of various classes of nanoparticles in diagnosing and treating retinoblastoma. It also presents the use of ligand-conjugated and smart nanoparticles in the active targeting of anticancer and imaging agents to the tumour cells. In addition, this review discusses the prospects and challenges in translating this nanocarrier into clinical use for retinoblastoma therapy. This review may provide new insight for formulation scientists to explore in order to facilitate the development of more effective and safer medicines for children suffering from retinoblastoma.

Nanotechnology based drug delivery systems for the treatment of anterior segment eye diseases.

Diseases affecting the anterior segment of the eye are the primary causes of vision impairment and blindness globally. Drug administration through the topical ocular route is widely accepted because of its user/patient friendliness - ease of administration and convenience. However, it remains a significant challenge to efficiently deliver drugs to the eye through this route because of various structural and physiological constraints that restrict the distribution of therapeutic molecules into the ocular tissues. The bioavailability of topically applied ocular medications such as eye drops is typically less than 5%. Developing novel delivery systems to increase the retention time on the ocular surfaces and permeation through the cornea is one of the approaches adopted to boost the bioavailability of topically administered medications. Drug delivery systems based on nanotechnology such as micelles, nanosuspensions, nanoparticles, nanoemulsions, liposomes, dendrimers, niosomes, cubosomes and nanowafers have been investigated as effective alternatives to conventional ocular delivery systems in treating diseases of the anterior segment of the eye. This review discussed different nanotechnology-based delivery systems that are currently investigated for treating and managing diseases affecting the anterior ocular tissues. We also looked at the challenges in translating these systems into clinical use and the prospects of nanocarriers as a vehicle for the delivery of phytoactive compounds to the anterior segment of the eye.

A guide to oral vaccination: Highlighting electrospraying as a promising manufacturing technique toward a successful oral vaccine development.

Most vaccines approved by regulatory bodies are administered via intramuscular or subcutaneous injections and have shortcomings, such as the risk of needle-associated blood infections, pain and swelling at the injection site. Orally administered vaccines are of interest, as they elicit both systemic and mucosal immunities, in which mucosal immunity would neutralize the mucosa invading pathogen before the onset of an infection. Hence, oral vaccination can eliminate the injection associated adverse effects and enhance the person's compliance. Conventional approaches to manufacturing oral vaccines, such as coacervation, spray drying, and membrane emulsification, tend to alter the structural proteins in vaccines that result from high temperature, organic and toxic solvents during production. Electrohydrodynamic processes, specifically electrospraying, could solve these challenges, as it also modulates antigen release and has a high loading efficiency. This review will highlight the mucosal immunity and biological basis of the gastrointestinal immune system, different oral vaccine delivery approaches, and the application of electrospraying in vaccines development.

Recent and advanced nano-technological strategies for COVID-19 vaccine development.

The outbreak of the COVID-19 pandemic in 2019 has been one of the greatest challenges modern medicine and science has ever faced. It has affected millions of people around the world and altered human life and activities as we once knew. The high prevalence as well as an extended period of incubations which usually does not present with symptoms have played a formidable role in the transmission and infection of millions. A lot of research has been carried out on developing suitable treatment and effective preventive measures for the control of the pandemic. Preventive strategies which include social distancing, use of masks, washing of hands, and contact tracing have been effective in slowing the spread of the virus; however, the infectious nature of the SARS-COV-2 has made these strategies unable to eradicate its spread. In addition, the continuous increase in the number of cases and death, as well as the appearance of several variants of the virus, has necessitated the development of effective and safe vaccines in a bid to ensure that human activities can return to normalcy. Nanotechnology has been of great benefit in the design of vaccines as nano-sized materials have been known to aid the safe and effective delivery of antigens as well as serve as suitable adjuvants to potentiate responses to vaccines. There are only four vaccine candidates currently approved for use in humans while many other candidates are at various levels of development. This review seeks to provide updated information on the current nano-technological strategies employed in the development of COVID-19 vaccines.

Development of lipid-based microsuspensions for improved ophthalmic delivery of gentamicin sulphate.

Aim: Anterior eye segment disorders are treated with eye drops and ointments, which have low ocular bioavailability necessitating the need for improved alternatives. Lipid microsuspension of gentamicin sulphate was developed for the treatment of susceptible eye diseases. Materials & methods: Lipid microsuspensions encapsulating gentamicin sulphate were produced by hot homogenization and evaluated. Ex vivo permeation and ocular irritancy tests were also conducted. Results & conclusion: Stable microsuspensions with high entrapment efficiency and satisfactory osmolarities were obtained. Release studies achieved 49-88% in vitro release at 12 h with sustained permeability of gentamicin compared with conventional gentamicin eye drop (Evril®). No irritation was observed following Draize's test. The microsuspensions have great potential as ocular delivery system of gentamicin sulphate.

COVID-19 and cancer: From basic mechanisms to vaccine development using nanotechnology.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a global pandemic which has induced unprecedented ramifications, severely affecting our society due to the long incubation time, unpredictably high prevalence and lack of effective vaccines. One of the interesting notions is that there is an association between COVID-19 and cancer. Cancer patients seem to exhibit exacerbated conditions and a higher mortality rate when exposed to the virus. Therefore, vaccines are the promising solution to minimise the problem amongst cancer patients threatened by the new viral strains. However, there are still limitations to be considered, including the efficacy of COVID vaccines for immunocompromised individuals, possible interactions between the vaccine and cancer, and personalised medicine. Not only to eradicate the pandemic, but also to make it more effective for immunocompromised patients who are suffering from cancer, a successful vaccine platform is required through the implementation of nanotechnology which can also enable scalable manufacturing and worldwide distribution along with its faster and precise delivery. In this review, we summarise the current understanding of COVID-19 with clinical perspectives, highlighting the association between COVID-19 and cancer, followed by a vaccine development for this association using nanotechnology. We suggest different administration methods for the COVID-19 vaccine formulation options. This study will contribute to paving the way towards the prevention and treatment of COVID-19, especially for the immunocompromised individuals.