Nanotechnology Applications to HIV Vaccines and Microbicides

Tracing the recent updates on vaccination approaches and significant adjuvants being developed against HIV

INTRODUCTION

Human Immunodeficiency Virus type 1 (HIV1); the causative agent of Acquired Immunodeficiency Syndrome (AIDS), has been a major target of the scientific community to develop an anti-viral therapy. Some successful discoveries have been made during the last two decades in the form of availability of antiviral therapy in endemic regions. Nevertheless, a total cure and safety vaccine has not yet been designed to eradicate HIV from the world.

AREAS COVERED

The purpose of this comprehensive study is to compile recent data regarding therapeutic interventions against HIV and to determine future research needs in this field. A systematic research strategy has been used to gather data from recent, most advanced published electronic sources. Literature based results show that experiments at the invitro level and animal models are continuously in research annals and are providing hope for human trials.

EXPERT OPINION

There is still a gap and more work is needed in the direction of modern drug and vaccination designs. Moreover coordination is necessary among researchers, educationists, public health workers, and the general community to communicate and coordinate the repercussions associated with the deadly disease. It is important for taking timely measures regarding mitigation and adaptation with HIV in future.

Nanoparticle-based strategies to target HIV-infected cells

Antiretroviral drugs employed for the treatment of human immunodeficiency virus (HIV) infections have remained largely ineffective due to their poor bioavailability, numerous adverse effects, modest uptake in infected cells, undesirable drug-drug interactions, the necessity for long-term drug therapy, and lack of access to tissues and reservoirs. Nanotechnology-based interventions could serve to overcome several of these disadvantages and thereby improve the therapeutic efficacy of antiretrovirals while reducing the morbidity and mortality due to the disease. However, attempts to use nanocarriers for the delivery of anti-retroviral drugs have started gaining momentum only in the past decade. This review explores in-depth the various nanocarriers that have been employed for the treatment of HIV infections highlighting their merits and possible demerits.

Microbiota and nanoparticles: Description and interactions

The healthy human body is inhabited with a large number of bacteria, forming natural flora. It is even estimated that for a human body, its amount of DNA is less important that its bacterial genetic material. This flora plays major roles in the sickness and health of the human body and any change in its composition may lead to different diseases. Nanoparticles are widely used in numerous fields: cosmetics, food, industry, and as drug delivery carrier in the medical field. Being included in these various applications, nanoparticles may interact with the human body at various levels and with different mechanisms. These interactions differ depending on the nanoparticle nature, its structure, its concentration and manifest in different ways on the microbiota, leading to its destabilization, its restoring or showing no toxic effect. Nanoparticles may also be used as a vehicle to regulate the microbiota or to treat some of its diseases.

Lipid Nanocarriers for Anti-HIV Therapeutics: A Focus on Physicochemical Properties and Biotechnological Advances

Since HIV was first identified, and in a relatively short period of time, AIDS has become one of the most devastating infectious diseases of the 21st century. Classical antiretroviral therapies were a major step forward in disease treatment options, significantly improving the survival rates of HIV-infected individuals. Even though these therapies have greatly improved HIV clinical outcomes, antiretrovirals (ARV) feature biopharmaceutic and pharmacokinetic problems such as poor aqueous solubility, short half-life, and poor penetration into HIV reservoir sites, which contribute to the suboptimal efficacy of these regimens. To overcome some of these issues, novel nanotechnology-based strategies for ARV delivery towards HIV viral reservoirs have been proposed. The current review is focused on the benefits of using lipid-based nanocarriers for tuning the physicochemical properties of ARV to overcome biological barriers upon administration. Furthermore, a correlation between these properties and the potential therapeutic outcomes has been established. Biotechnological advancements using lipid nanocarriers for RNA interference (RNAi) delivery for the treatment of HIV infections were also discussed.

Recent advances in siRNA delivery mediated by lipid-based nanoparticles

Small interfering RNA (siRNA) has been expected to be a unique pharmaceutic for the treatment of broad-spectrum intractable diseases. However, its unfavorable properties such as easy degradation in the blood and negative-charge density are still a formidable barrier for clinical use. For disruption of this barrier, siRNA delivery technology has been significantly advanced in the past two decades. The approval of Patisiran (ONPATTRO™) for the treatment of transthyretin-mediated amyloidosis, the first approved siRNA drug, is a most important milestone. Since lipid-based nanoparticles (LNPs) are used in Patisiran, LNP-based siRNA delivery is now of significant interest for the development of the next siRNA formulation. In this review, we describe the design of LNPs for the improvement of siRNA properties, bioavailability, and pharmacokinetics. Recently, a number of siRNA-encapsulated LNPs were reported for the treatment of intractable diseases such as cancer, viral infection, inflammatory neurological disorder, and genetic diseases. We believe that these contributions address and will promote the development of an effective LNP-based siRNA delivery system and siRNA formulation.

Nanotechnology and the future of condoms in the prevention of sexually transmitted infections

Objective

The human immunodeficiency virus (HIV) is among the utmost destructive viruses humankind has ever faced in almost four decades. It carries with it profound socioeconomic and public health implications. Unfortunately, there is, currently, no effective cure for HIV infections. This review discusses the various types of condoms, microbicides, and the potential use of nanoparticle-coated condoms as a means of diminishing the risk of HIV transmission and sexually transmitted infections (STIs) during sexual intercourse.

Methods

We identified 153 articles from 1989 to 2015 indexed in various journal platforms, reports, and magazines. Using the PRISMA guidelines as proxy in performing the research review process, only 53 articles were selected. Ideally, articles that failed to describe the nature and types of condoms, condom failures, nanoparticle-coated condoms, microbicides, and HIV prevention were excluded.

Results and Discussion

In general, it has been shown that antiretroviral therapy (ART) currently available can only limit transmission and acquisition of HIV strains. Apart from ART treatment, the use of condoms has been identified globally as a cost-effective intervention for reducing the spread of HIV and other STIs. However, while condoms are supposed to be effective, reliable, and easy to use, research has shown that they are attributable to 20% failures including breakages. Nevertheless, other studies have shown that coating condoms with nanoparticles is an important and effective method for reducing condom breakage and HIV/STI transmission during sexual intercourse.

Conclusions

A review of literature cited in this paper has shown that nanotechnology-based condom systems have the potential to prevent the spread of HIV and STIs. Furthermore, the antimicrobial nature of some nanoparticles could provide a safe and efficient way to disrupt and/or inactivate different STIs - including viral, bacterial, and fungal diseases.

The role of nanotechnology in the treatment of viral infections

Infectious diseases are the leading cause of mortality worldwide, with viruses in particular making global impact on healthcare and socioeconomic development. In addition, the rapid development of drug resistance to currently available therapies and adverse side effects due to prolonged use is a serious public health concern. The development of novel treatment strategies is therefore required. The interaction of nanostructures with microorganisms is fast-revolutionizing the biomedical field by offering advantages in both diagnostic and therapeutic applications. Nanoparticles offer unique physical properties that have associated benefits for drug delivery. These are predominantly due to the particle size (which affects bioavailability and circulation time), large surface area to volume ratio (enhanced solubility compared to larger particles), tunable surface charge of the particle with the possibility of encapsulation, and large drug payloads that can be accommodated. These properties, which are unlike bulk materials of the same compositions, make nanoparticulate drug delivery systems ideal candidates to explore in order to achieve and/or improve therapeutic effects. This review presents a broad overview of the application of nanosized materials for the treatment of common viral infections.

Triple Drug Combination of Zidovudine, Efavirenz and Lamivudine Loaded Lactoferrin Nanoparticles: an Effective Nano First-Line Regimen for HIV Therapy

PURPOSE

To enhance efficacy, bioavailability and reduce toxicity of first-line highly active anti-retroviral regimen, zidovudine + efavirenz + lamivudine loaded lactoferrin nanoparticles were prepared (FLART-NP) and characterized for physicochemical properties, bioactivity and pharmacokinetic profile.

METHODS

Nanoparticles were prepared using sol-oil protocol and characterized using different sources such as FE-SEM, AFM, NanoSight, and FT-IR. In-vitro and in-vivo studies have been done to access the encapsulation-efficiency, cellular localization, release kinetics, safety analysis, biodistribution and pharmacokinetics.

RESULTS

FLART-NP with a mean diameter of 67 nm (FE-SEM) and an encapsulation efficiency of >58% for each drug were prepared. In-vitro studies suggest that FLART-NP deliver the maximum of its payload at pH5 with a minimum burst release throughout the study period with negligible toxicity to the erythrocytes plus improved in-vitro anti-HIV activity. FLART-NP has improved the in-vivo pharmacokinetics (PK) profiles over the free drugs; an average of >4fold increase in AUC and AUMC, 30% increase in the C_max, >2fold in the half-life of each drug. Biodistribution data suggest that FLART-NP has improved the bioavailability of all drugs with less tissue-related inflammation as suggested with histopathological evaluation CONCLUSIONS: The triple-drug loaded nanoparticles have various advantages against soluble (free) drug combination in terms of enhanced bioavailability, improved PK profile and diminished drug-associated toxicity.

Nanomedicine in the development of anti-HIV microbicides

Prevention plays an invaluable role in the fight against HIV/AIDS. The use of microbicides is considered an interesting potential approach for topical pre-exposure prophylaxis of HIV sexual transmission. The prospects of having an effective product available are expected to be fulfilled in the near future as driven by recent and forthcoming results of clinical trials. Different dosage forms and delivery strategies have been proposed and tested for multiple microbicide drug candidates presently at different stages of the development pipeline. One particularly interesting approach comprises the application of nanomedicine principles to the development of novel anti-HIV microbicides, but its implications to efficacy and safety are not yet fully understood. Nanotechnology-based systems, either presenting inherent anti-HIV activity or acting as drug nanocarriers, may significantly influence features such as drug solubility, stability of active payloads, drug release, interactions between active moieties and virus/cells, intracellular drug delivery, drug targeting, safety, antiviral activity, mucoadhesive behavior, drug distribution and tissue penetration, and pharmacokinetics. The present manuscript provides a comprehensive and holistic overview of these topics as relevant to the development of vaginal and rectal microbicides. In particular, recent advances pertaining inherently active microbicide nanosystems and microbicide drug nanocarriers are discussed.

Role of nanotechnology in HIV/AIDS vaccine development

HIV/AIDS is one of the worst crises affecting global health and influencing economic development and social stability. Preventing and treating HIV infection is a crucial task. However, there is still no effective HIV vaccine for clinical application. Nanotechnology has the potential to solve the problems associated with traditional HIV vaccines. At present, various nano-architectures and nanomaterials can function as potential HIV vaccine carriers or adjuvants, including inorganic nanomaterials, liposomes, micelles and polymer nanomaterials. In this review, we summarize the current progress in the use of nanotechnology for the development of an HIV/AIDS vaccine and discuss its potential to greatly improve the solubility, permeability, stability and pharmacokinetics of HIV vaccines. Although nanotechnology holds great promise for applications in HIV/AIDS vaccines, there are still many inadequacies that result in a variety of risks and challenges. The potential hazards to the human body and environment associated with some nano-carriers, and their underlying mechanisms require in-depth study. Non-toxic or low-toxic nanomaterials with adjuvant activity have been identified. However, studying the confluence of factors that affect the adjuvant activity of nanomaterials may be more important for the optimization of the dosage and immunization strategy and investigations into the exact mechanism of action. Moreover, there are no uniform standards for investigations of nanomaterials as potential vaccine adjuvants. These limitations make it harder to analyze and deduce rules from the existing data. Developing vaccine nano-carriers or adjuvants with high benefit-cost ratios is important to ensure their broad usage. Despite some shortcomings, nanomaterials have great potential and application prospects in the fields of AIDS treatment and prevention.

TLc-A, the leading nanochelating-based nanochelator, reduces iron overload in vitro and in vivo

Iron chelation therapy is an effective approach to the treatment of iron overload conditions, in which iron builds up to toxic levels in the body and may cause organ damage. Treatments using deferoxamine, deferasirox and deferiprone have been introduced and despite their disadvantages, they remain the first-line therapeutics in iron chelation therapy. Our study aimed to compare the effectiveness of the iron chelation agent TLc-A, a nano chelator synthetized based on the novel nanochelating technology, with deferoxamine. We found that TLc-A reduced iron overload in Caco2 cell line more efficiently than deferoxamine. In rats with iron overload, very low concentrations of TLc-A lowered serum iron level after only three injections of the nanochelator, while deferoxamine was unable to reduce iron level after the same number of injections. Compared with deferoxamine, TLc-A significantly increased urinary iron excretion and reduced hepatic iron content. The toxicity study showed that the intraperitoneal median lethal dose for TLc-A was at least two times higher than that for deferoxamine. In conclusion, our in vitro and in vivo studies indicate that the novel nano chelator compound, TLc-A, offers superior performance in iron reduction than the commercially available and widely used deferoxamine.

A Multiple siRNA-Based Anti-HIV/SHIV Microbicide Shows Protection in Both In Vitro and In Vivo Models

Human immunodeficiency virus (HIV) types 1 and 2 (HIV-1 and HIV-2) are the etiologic agents of AIDS. Most HIV-1 infected individuals worldwide are women, who acquire HIV infections during sexual contact. Blocking HIV mucosal transmission and local spread in the female lower genital tract is important in preventing infection and ultimately eliminating the pandemic. Microbicides work by destroying the microbes or preventing them from establishing an infection. Thus, a number of different types of microbicides are under investigation, however, the lack of their solubility and bioavailability, and toxicity has been major hurdles. Herein, we report the development of multifunctional chitosan-lipid nanocomplexes that can effectively deliver plasmids encoding siRNA(s) as microbicides without adverse effects and provide significant protection against HIV in both in vitro and in vivo models. Chitosan or chitosan-lipid (chlipid) was complexed with a cocktail of plasmids encoding HIV-1-specific siRNAs (psiRNAs) and evaluated for their efficacy in HEK-293 cells, PBMCs derived from nonhuman primates, 3-dimensional human vaginal ectocervical tissue (3D-VEC) model and also in non-human primate model. Moreover, prophylactic administration of the chlipid to deliver a psiRNA cocktail intravaginally with a cream formulation in a non-human primate model showed substantial reduction of SHIV (simian/human immunodeficiency virus SF162) viral titers. Taken together, these studies demonstrate the potential of chlipid-siRNA nanocomplexes as a potential genetic microbicide against HIV infections.

Dendrimers as nonviral vectors in dendritic cell-based immunotherapies against human immunodeficiency virus: steps toward their clinical evaluation

Although the antiretroviral therapy has led to a long-term control of HIV-1, it does not cure the disease. Therefore, several strategies are being explored to develop an effective HIV vaccine, such as the use of dendritic cells (DCs). DC-based immunotherapies bear different limitations, but one of the most critical point is the antigen loading into DCs. Nanotechnology offers new tools to overcome these constraints. Dendrimers have been proposed as carriers for targeted delivery of HIV antigens in DCs. These nanosystems can release the antigens in a controlled manner leading to a more potent specific immune response. This review focuses on the first steps for clinical development of dendrimers to assess their safety and potential use in DC-based immunotherapies against HIV.

Advances in Integrative Nanomedicine for Improving Infectious Disease Treatment in Public Health

INTRODUCTION

Infectious diseases present public health challenges worldwide. An emerging integrative approach to treating infectious diseases is using nanoparticle (NP) forms of traditional and alternative medicines. Advantages of nanomedicine delivery methods include better disease targeting, especially for intracellular pathogens, ability to cross membranes and enter cells, longer duration drug action, reduced side effects, and cost savings from lower doses.

METHODS

We searched Pubmed articles in English with keywords related to nanoparticles and nanomedicine. Nanotechnology terms were also combined with keywords for drug delivery, infectious diseases, herbs, antioxidants, homeopathy, and adaptation.

RESULTS

NPs are very small forms of material substances, measuring 1-100 nanometers along at least one dimension. Compared with bulk forms, NPs' large ratio of surface-area-to-volume confers increased reactivity and adsorptive capacity, with unique electromagnetic, chemical, biological, and quantum properties. Nanotechnology uses natural botanical agents for green manufacturing of less toxic NPs.

DISCUSSION

Nanoparticle herbs and nutriceuticals can treat infections via improved bioavailability and antiinflammatory, antioxidant, and immunomodulatory effects. Recent studies demonstrate that homeopathic medicines may contain source and/or silica nanoparticles because of their traditional manufacturing processes. Homeopathy, as a form of nanomedicine, has a promising history of treating epidemic infectious diseases, including malaria, leptospirosis and HIV/AIDS, in addition to acute upper respiratory infections. Adaptive changes in the host's complex networks underlie effects.

CONCLUSIONS

Nanomedicine is integrative, blending modern technology with natural products to reduce toxicity and support immune function. Nanomedicine using traditional agents from alternative systems of medicine can facilitate progress in integrative public health approaches to infectious diseases.

DNA vaccines: roles against diseases

Vaccination is the most successful application of immunological principles to human health. Vaccine efficacy needs to be reviewed from time to time and its safety is an overriding consideration. DNA vaccines offer simple yet effective means of inducing broad-based immunity. These vaccines work by allowing the expression of the microbial antigen inside host cells that take up the plasmid. These vaccines function by generating the desired antigen inside the cells, with the advantage that this may facilitate presentation through the major histocompatibility complex. This review article is based on a literature survey and it describes the working and designing strategies of DNA vaccines. Advantages and disadvantages for this type of vaccines have also been explained, together with applications of DNA vaccines. DNA vaccines against cancer, tuberculosis, Edwardsiella tarda, HIV, anthrax, influenza, malaria, dengue, typhoid and other diseases were explored.