Recent advancements in the field of nanotechnology for the delivery of anti-Alzheimer drug in the brain region

Recent Avenues in Novel Patient-Friendly Techniques for the Treatment of Diabetes

Background:

Diabetes is one of the most common chronic metabolic disorders which affect the quality of human life worldwide. As per the WHO report, between 1980 to 2014, the number of diabetes patients increases from 108 million to 422 million, with a global prevalence rate of 8.5% per year. Diabetes is the prime reason behind various other diseases like kidney failure, stroke, heart disorders, glaucoma, etc. It is recognized as the seventh leading cause of death throughout the world. The available therapies are painful (insulin injections) and inconvenient due to higher dosing frequency. Thus, to find out a promising and convenient treatment, extensive investigations are carried out globally by combining novel carrier system (like microparticle, microneedle, nanocarrier, microbeads etc.) and delivery devices (insulin pump, stimuli-responsive device, inhalation system, bioadhesive patch, insulin pen etc.) for more precise diagnosis and painless or less invasive treatment of disease.

Objective:

The review article is made with an objective to compile information about various upcoming and existing modern technologies developed to provide greater patient compliance and reduce the undesirable side effect of the drug. These devices evade the necessity of daily insulin injection and offer a rapid onset of action, which sustained for a prolonged duration of time to achieve a better therapeutic effect.

Conclusion:

Despite numerous advantages, various commercialized approaches, like Afrezza (inhalation insulin) have been a failure in recent years. Such results call for more potential work to develop a promising system. The novel approaches range from the delivery of non-insulin blood glucose lowering agents to insulin-based therapy with minimal invasion are highly desirable.

Multifunctional nano-enabled delivery systems in Alzheimer's disease management

This review discusses the recent advances in multifunctional nano-enabled delivery systems (NDS) for Alzheimer's disease management, including multitherapeutics, multimodal imaging-guided diagnostics, and theranostics.

Design and Biological Evaluation of Lipoprotein-Based Donepezil Nanocarrier for Enhanced Brain Uptake through Oral Delivery

Alzheimer's disease (AD) is a progressive neurodegenerative disorder associated with memory and cognitive impairment. Donepezil is an acetylcholinesterase inhibitor used for the symptomatic treatment of AD. However, high dose of donepezil is prescribed to achieve effective concentration in the brain, which leads to significant side effects, gastrointestinal alterations, and hepatotoxicity. In the present study, ApoE3 conjugated polymeric nanoparticles derived from diblock copolymer methoxy poly(ethylene glycol)-polycaprolactone (mPEG-PCL) have been used to boost the delivery of donepezil to the brain. mPEG-PCL is an amphiphilic diblock polymer with a tendency to avoid nanoparticle uptake by phagocytic cells in the liver and can significantly reduce the gastric mucosal irritations. Moreover, ApoE3-based nanocarriers showed a promising ability to enhance brain uptake, binding to amyloid beta with high affinity and accelerating its clearance. Donepezil-loaded polymeric nanoparticles were performed by using a nanoprecipitation method and further surface modified with polysorbate 80 and ApoE3 to increase the brain bioavailability and reduce the dose. Optimization of various process parameters were performed using quality by design approach. ApoE3 polymeric nanoparticles were found to be stable in simulated gastric fluids and exhibited a sustained drug release pattern. Cellular uptake studies confirmed better neuronal uptake of the developed formulation, which is further corroborated with pharmacokinetic and biodistribution studies. Orally administered ApoE3 polymeric nanoparticles resulted in significantly higher brain donepezil levels after 24 h (84.97 ± 11.54 ng/mg tissue) as compared to the pure drug (not detected), suggesting a significant role of surface coating. Together, these findings are promising and offer preclinical evidence for better brain availability of donepezil by oral administration.

Recent expansions of novel strategies towards the drug targeting into the brain

The treatment of central nervous system (CNS) disorders always remains a challenge for the researchers. The presence of various physiological barriers, primarily the blood-brain barrier (BBB) limits the accessibility of the brain and hinders the efficacy of various drug therapies. Hence, drug targeting to the brain, particularly to the diseased cells by circumventing the physiological barriers is essential to develop a promising therapy for the treatment of brain disorders. Presently, the investigations emphasize the role of different nanocarrier systems or surface modified target specific novel carrier system to improve the efficiency and reduce the side effects of the brain therapeutics. Such approaches supposed to circumvent the BBB or have the ability to cross the barrier function and thus increases the drug concentration in the brain. Although the efficacy of novel carrier system depends upon various physiological factors like active efflux transport, protein corona of the brain, stability, and toxicity of the nanocarrier, physicochemical properties, patient-related factors and many more. Hence, to develop a promising carrier system, it is essential to understand the physiology of the brain and BBB and also the other associated factors. Along with this, some alternative route like direct nose-to-brain drug delivery can also offer a better means to access the brain without exposure of the BBB. In this review, we have discussed the role of various physiological barriers including the BBB and blood-cerebrospinal fluid barrier (BCSFB) on the drug therapy and the mechanism of drug transport across the BBB. Further, we discussed different novel strategies for brain targeting of drug including, polymeric nanoparticles, lipidic nanoparticles, inorganic nanoparticles, liposomes, nanogels, nanoemulsions, dendrimers, quantum dots, etc. along with the intranasal drug delivery to the brain. We have also illustrated various factors affecting the drug targeting efficiency of the developed novel carrier system.

Lactoferrin in Aseptic and Septic Inflammation

Lactoferrin (Lf), a cationic glycoprotein able to chelate two ferric irons per molecule, is synthesized by exocrine glands and neutrophils. Since the first anti-microbial function attributed to Lf, several activities have been discovered, including the relevant anti-inflammatory one, especially associated to the down-regulation of pro-inflammatory cytokines, as IL-6. As high levels of IL-6 are involved in iron homeostasis disorders, Lf is emerging as a potent regulator of iron and inflammatory homeostasis. Here, the role of Lf against aseptic and septic inflammation has been reviewed. In particular, in the context of aseptic inflammation, as anemia of inflammation, preterm delivery, Alzheimer’s disease and type 2 diabetes, Lf administration reduces local and/or systemic inflammation. Moreover, Lf oral administration, by decreasing serum IL-6, reverts iron homeostasis disorders. Regarding septic inflammation occurring in Chlamydia trachomatis infection, cystic fibrosis and inflammatory bowel disease, Lf, besides the anti-inflammatory activity, exerts a significant activity against bacterial adhesion, invasion and colonization. Lastly, a critical analysis of literature in vitro data reporting contradictory results on the Lf role in inflammatory processes, ranging from pro- to anti-inflammatory activity, highlighted that they depend on cell models, cell metabolic status, stimulatory or infecting agents as well as on Lf iron saturation degree, integrity and purity.

Recent Expansions on Cellular Models to Uncover the Scientific Barriers Towards Drug Development for Alzheimer's Disease

Globally, the central nervous system (CNS) disorders appear as the most critical pathological threat with no proper cure. Alzheimer's disease (AD) is one such condition frequently observed with the aged population and sometimes in youth too. Most of the research utilizes different animal models for in vivo study of AD pathophysiology and to investigate the potency of the newly developed therapy. These in vivo models undoubtably provide a powerful investigation tool to study human brain. Although, it sometime fails to mimic the exact environment and responses as the human brain owing to the distinctive genetic and anatomical features of human and rodent brain. In such condition, the in vitro cell model derived from patient specific cell or human cell lines can recapitulate the human brain environment. In addition, the frequent use of animals in research increases the cost of study and creates various ethical issues. Instead, the use of in vitro cellular models along with animal models can enhance the translational values of in vivo models and represent a better and effective mean to investigate the potency of therapeutics. This strategy also limits the excessive use of laboratory animal during the drug development process. Generally, the in vitro cell lines are cultured from AD rat brain endothelial cells, the rodent models, human astrocytes, human brain capillary endothelial cells, patient derived iPSCs (induced pluripotent stem cells) and also from the non-neuronal cells. During the literature review process, we observed that there are very few reviews available which describe the significance and characteristics of in vitro cell lines, for AD investigation. Thus, in the present review article, we have compiled the various in vitro cell lines used in AD investigation including HBMEC, BCECs, SHSY-5Y, hCMEC/D3, PC-2 cell line, bEND3 cells, HEK293, hNPCs, RBE4 cells, SK-N-MC, BMVECs, CALU-3, 7W CHO, iPSCs and cerebral organoids cell lines and different types of culture media such as SCM, EMEM, DMEM/F12, RPMI, EBM and 3D-cell culture.

Biomedical applications of microemulsion through dermal and transdermal route

Microemulsions are thermodynamically stable, transparent, colloidal drug carrier system extensively used by the scientists for effective drug delivery across the skin. It is a spontaneous isotropic mixture of lipophilic and hydrophilic substances stabilized by suitable surfactant and co-surfactant. The easy fabrication, long-term stability, enhanced solubilization, biocompatibility, skin-friendly appearance and affinity for both the hydrophilic and lipophilic drug substances make it superior for skin drug delivery over the other carrier systems. The topical administration of most of the active compounds is impaired by limited skin permeability due to the presence of skin barriers. In this sequence, the microemulsion represents a cost-effective and convenient drug carrier system which successfully delivers the drug to and across the skin. In the present review work, we compiled various attempts made in last 20 years, utilizing the microemulsion for dermal and transdermal delivery of various drugs. The review emphasizes the potency of microemulsion for topical and transdermal drug delivery and its effect on drug permeability.