Optimizing the preparation and stability of decorated antiretroviral drug nanocrystals

Drug Nanocrystals: A Delivery Channel for Antiviral Therapies

Viral infections represent a significant threat to global health due to their highly communicable and potentially lethal nature. Conventional antiviral interventions encounter challenges such as drug resistance, tolerability issues, specificity concerns, high costs, side effects, and the constant mutation of viral proteins. Consequently, the exploration of alternative approaches is imperative. Therefore, nanotechnology-embedded drugs excelled as a novel approach purporting severe life-threatening viral disease. Integrating nanomaterials and nanoparticles enables ensuring precise drug targeting, improved drug delivery, and fostered pharmacokinetic properties. Notably, nanocrystals (NCs) stand out as one of the most promising nanoformulations, offering remarkable characteristics in terms of physicochemical properties (higher drug loading, improved solubility, and drug retention), pharmacokinetics (enhanced bioavailability, dose reduction), and optical properties (light absorptivity, photoluminescence). These attributes make NCs effective in diagnosing and ameliorating viral infections. This review comprises the prevalence, pathophysiology, and resistance of viral infections along with emphasizing on failure of current antivirals in the management of the diseases. Moreover, the review also highlights the role of NCs in various viral infections in mitigating, diagnosing, and other NC-based strategies combating viral infections. In vitro, in vivo, and clinical studies evident for the effectiveness of NCs against viral pathogens are also discussed.

Curcumin nanocrystals-in-nanofibres as a promising platform for the management of periodontal disease

It is estimated that nearly a half of the world's population over 30 years old suffer from some kind of periodontal disease (PD). Although preventable, PD can pose a significant health burden to patients, causing from pain and discomfort to disfigurement and death. The management of PD often requires surgical procedures accompanied of systemic antibiotic and anti-inflammatory treatments. Curcumin (CUR), a potent anti-inflammatory and antimicrobial active, has shown great promise in the management of PD; however, its effects are often limited by its low bioavailability. In this work, we report the development of electrospun nanofibres (NFs) loaded with CUR nanocrystals (NCs) for the management of PD. NCs of 100 nm were obtained by media milling and loaded into dissolving polyvinyl alcohol NFs using electrospinning. The resultant NCs-in-NFs dissolved in water spontaneously, releasing NCs with a particle size of ∼120 nm. The physiochemical characterisation of the systems indicated the absence of chemical interactions between drug and polymer, and nanofibres with an amorphous nature. In vitro release profiles demonstrated that the NCs had a significantly higher dissolution rate (∼100 % at day 40) than the control group (approximately 6 % at day 40), which consisted of NFs containing a physical mixture of the drug and stabiliser. Finally, mucosal deposition studies demonstrated a 10-fold higher capacity of the novel NCs-in-NFs system to deposit CUR ex vivo using excised neonatal porcine mucosal tissue, when compared to the control group.

The multivalency game ruling the biology of immunity

Macrophages play a crucial role in our immune system, preserving tissue health and defending against harmful pathogens. This article examines the diversity of macrophages influenced by tissue-specific functions and developmental origins, both in normal and disease conditions. Understanding the spectrum of macrophage activation states, especially in pathological situations where they contribute significantly to disease progression, is essential to develop targeted therapies effectively. These states are characterized by unique receptor compositions and phenotypes, but they share commonalities. Traditional drugs that target individual entities are often insufficient. A promising approach involves using multivalent systems adorned with multiple ligands to selectively target specific macrophage populations based on their phenotype. Achieving this requires constructing supramolecular structures, typically at the nanoscale. This review explores the theoretical foundation of engineered multivalent nanosystems, dissecting the key parameters governing specific interactions. The goal is to design targeting systems based on distinct cell phenotypes, providing a pragmatic approach to navigating macrophage heterogeneity's complexities for more effective therapeutic interventions.

Recent Developments in Drug Delivery for Treatment of Tuberculosis by Targeting Macrophages

Tuberculosis (TB) is among the greatest public health and safety concerns in the 21st century, Mycobacterium tuberculosis, which causes TB, infects alveolar macrophages and uses these cells as one of its primary sites of replication. The current TB treatment regimen, which consist of chemotherapy involving a combination of 3-4 antimicrobials for a duration of 6-12 months, is marked with significant side effects, toxicity, and poor compliance. Targeted drug delivery offers a strategy that could overcome many of the problems of current TB treatment by specifically targeting infected macrophages. Recent advances in nanotechnology and material science have opened an avenue to explore drug carriers that actively and passively target macrophages. This approach can increase the drug penetration into macrophages by using ligands on the nanocarrier that interact with specific receptors for macrophages. This review encompasses the recent development of drug carriers specifically targeting macrophages actively and passively. Future directions and challenges associated with development of effective TB treatment is also discussed.

Formulation of Cabotegravir Loaded Gold Nanoparticles: Optimization, Characterization to In-Vitro Cytotoxicity Study

The effective and preventive treatment of HIV is one of the difficult challenges worldwide. It requires the development of an effective prophylactic strategy to prevent HIV/AIDS. This study aimed to synthesize Cabotegravir (CAB)-biodegradable gold (Au) nanoparticles by using pectin as a reducer and stabilizer. CAB-GNPs were prepared by the slightly modified Turkevich method. CAB-GNPs were optimized using Box Behnken design for independent variables gold chloride (A), pectin (B) and pH range (C). The effects of independent variables were observed on particle size (Y1) and encapsulation efficiency (Y2). The results of the study revealed that the optimized nanoparticles (GLN7) had a particle size of 3.9 ± 0.1 nm and encapsulation efficiency of 97.2 ± 3.9%. TEM study showed the spherical shape particles. The in-vitro drug release revealed 62.1 ± 0.5% release of CAB in simulated gastric buffer (pH 1.2) and 45.5 ± 2.8% in physiological buffer (pH 7.4). In-vitro cytotoxicity study and antibacterial activity depicted the safety of the prepared NPs by showing lesser toxicity than pure CAB. From the results, our experimental outcomes concluded that CAB gold nanoparticles composed of pectin may constitute a preferred embodiment for the delivery of CAB.

Long-acting antiretrovirals: a new era for the management and prevention of HIV infection

The long-acting antiretroviral cabotegravir and rilpivirine combination has just received FDA, EMA and Health Canada approval. This novel drug delivery approach is about to revolutionize the therapy of people living with HIV, decreasing the 365 daily pill burden to only six intramuscular injections per year. In addition, islatravir, a first-in-class nucleoside reverse transcriptase translocation inhibitor, is intended to be formulated as an implant with a dosing interval of 1 year or more. At present, long-acting antiretroviral therapies (LA-ARTs) are given at fixed standard doses, irrespectively of the patient's weight and BMI, and without consideration for host genetic and non-genetic factors likely influencing their systemic disposition. Despite a few remaining challenges related to administration (e.g. pain, dedicated medical procedure), the development and implementation of LA-ARTs can overcome long-term adherence issues by improving patients' privacy and reducing social stigma associated with the daily oral intake of anti-HIV treatments. Yet, the current 'one-size-fits-all' approach does not account for the recognized significant inter-individual variability in LA-ART pharmacokinetics. Therapeutic drug monitoring (TDM), an important tool for precision medicine, may provide physicians with valuable information on actual drug exposure in patients, contributing to improve their management in real life. The present review aims to update the current state of knowledge on these novel promising LA-ARTs and discusses their implications, particularly from a clinical pharmacokinetics perspective, for the future management and prevention of HIV infection, issues of ongoing importance in the absence of curative treatment or an effective vaccine.

Long-acting approaches for delivery of antiretroviral drugs for prevention and treatment of HIV: a review of recent research

INTRODUCTION

Despite significant advances in treatment and prevention of HIV-1 infection, poor adherence to daily combination antiretroviral therapy (ART) regimens remains a major obstacle toward achieving sustained viral suppression and prevention. Adherence to ART could also be compromised by adverse drug reactions and societal factors that limit access to therapy. Therefore, medicines that aim to improve adherence by limiting ART side effects, frequency of dosing and socially acceptable regimens are becoming more attractive.

AREAS COVERED

This review highlights recent advances and challenges in the development of long-acting drug delivery strategies for HIV prevention and treatment. Approaches for extended oral and transdermal deliveries, microbicides, broadly neutralizing antibodies, and long-acting implantable and injectable deliveries are reviewed.

EXPERT OPINION

Emerging approaches on long-acting antiretroviral therapies and broadly neutralizing antibody technologies are currently at various stages of development. Such efforts, if successful and become broadly accepted by clinicians and users, will provide newer and simpler options for prevention and treatment of HIV infection.

A long-acting 3TC ProTide nanoformulation suppresses HBV replication in humanized mice

Nowadays, there is a strong request for the treatment of chronic HBV-infection with direct acting antivirals. Furthermore, prevalent human immunodeficiency virus (HIV-1) and hepatitis B (HBV) co-infections highlight an immediate need for dual long-acting and easily administered antivirals. To this end, we modified lamivudine (3TC), a nucleoside analog inhibitor of both viruses, into a lipophilic monophosphorylated prodrug (M23TC). Prior work demonstrated that nanoformulation of M23TC (NM23TC) enhanced drug stability, controlled dissolution and improved access to sites of viral replication. The present study evaluated the efficacy of a NM23TC in HBV-infected chimeric liver humanized mice. Levels of HBV DNA and HBsAg in plasma were monitored up to 8 weeks posttreatment. A single intramuscular dose of 75 mg/kg 3TC equivalents of nanoformulated NM23TC provided sustained drug levels and suppressed HBV replication in humanized mice for 4 weeks. The results support further development of this long-acting 3TC nanoformulation for HBV treatment and prevention.

A year-long extended release nanoformulated cabotegravir prodrug

Long-acting cabotegravir (CAB) extends antiretroviral drug administration from daily to monthly. However, dosing volumes, injection site reactions and health-care oversight are obstacles towards a broad usage. The creation of poloxamer-coated hydrophobic and lipophilic CAB prodrugs with controlled hydrolysis and tissue penetrance can overcome these obstacles. To such ends, fatty acid ester CAB nanocrystal prodrugs with 14, 18 and 22 added carbon chains were encased in biocompatible surfactants named NMCAB, NM2CAB and NM3CAB and tested for drug release, activation, cytotoxicity, antiretroviral activities, pharmacokinetics and biodistribution. Pharmacokinetics studies, performed in mice and rhesus macaques, with the lead 18-carbon ester chain NM2CAB, showed plasma CAB levels above the protein-adjusted 90% inhibitory concentration for up to a year. NM2CAB, compared with NMCAB and NM3CAB, demonstrated a prolonged drug release, plasma circulation time and tissue drug concentrations after a single 45 mg per kg body weight intramuscular injection. These prodrug modifications could substantially improve CAB's effectiveness.

Synthesis and Characterization of Long-Acting Darunavir Prodrugs

Antiretroviral therapy (ART) has improved the quality of life in patients infected with HIV-1. However, complete viral suppression within anatomical compartments remains unattainable. This is complicated by adverse side effects and poor adherence to lifelong therapy leading to the emergence of viral drug resistance. Thus, there is an immediate need for cellular and tissue-targeted long-acting (LA) ART formulations. Herein, we describe two LA prodrug formulations of darunavir (DRV), a potent antiretroviral protease inhibitor. Two classes of DRV prodrugs, M1DRV and M2DRV, were synthesized as lipophilic and hydrophobic prodrugs and stabilized into aqueous suspensions designated NM1DRV and NM2DRV. The formulations demonstrated enhanced intracellular prodrug levels with sustained drug retention and antiretroviral activities for 15 and 30 days compared to native DRV formulation in human monocyte-derived macrophages. Pharmacokinetics tests of NM1DRV and NM2DRV administered to mice demonstrated sustained drug levels in blood and tissues for 30 days. These data, taken together, support the idea that LA DRV with sustained antiretroviral responses through prodrug nanoformulations is achievable.

A long acting nanoformulated lamivudine ProTide

A long acting (LA) hydrophobic and lipophilic lamivudine (3TC) was created as a phosphoramidate pronucleotide (designated M23TC). M23TC improved intracellular delivery of active triphosphate metabolites and enhanced antiretroviral and pharmacokinetic (PK) profiles over the native drug. A single treatment of human monocyte derived macrophages (MDM) with nanoformulated M23TC (NM23TC) improved drug uptake, retention, intracellular 3TC triphosphates and antiretroviral activities in MDM and CD4⁺ T cells. PK tests of NM23TC administered to Sprague Dawley rats demonstrated sustained prodrug and drug triphosphate levels in blood and tissues for 30 days. The development of NM23TC remains a substantive step forward in producing LA slow effective release antiretrovirals for future clinical translation.

Synthesis of a long acting nanoformulated emtricitabine ProTide

While antiretroviral therapy (ART) has revolutionized treatment and prevention of human immunodeficiency virus type one (HIV-1) infection, regimen adherence, viral mutations, drug toxicities and access stigma and fatigue are treatment limitations. These have led to new opportunities for the development of long acting (LA) ART including implantable devices and chemical drug modifications. Herein, medicinal and formulation chemistry were used to develop LA prodrug nanoformulations of emtricitabine (FTC). A potent lipophilic FTC phosphoramidate prodrug (M2FTC) was synthesized then encapsulated into a poloxamer surfactant (NM2FTC). These modifications extended the biology, apparent drug half-life and antiretroviral activities of the formulations. NM2FTC demonstrated a >30-fold increase in macrophage and CD4+ T cell drug uptake with efficient conversion to triphosphates (FTC-TP). Intracellular FTC-TP protected macrophages against an HIV-1 challenge for 30 days. A single intramuscular injection of NM2FTC, at 45 mg/kg native drug equivalents, into Sprague Dawley rats resulted in sustained prodrug levels in blood, liver, spleen and lymph nodes and FTC-TP in lymph node and spleen cells at one month. In contrast, native FTC-TPs was present for one day. These results are an advance in the transformation of FTC into a LA agent.

Neurotheranostics as personalized medicines

The discipline of neurotheranostics was forged to improve diagnostic and therapeutic clinical outcomes for neurological disorders. Research was facilitated, in largest measure, by the creation of pharmacologically effective multimodal pharmaceutical formulations. Deployment of neurotheranostic agents could revolutionize staging and improve nervous system disease therapeutic outcomes. However, obstacles in formulation design, drug loading and payload delivery still remain. These will certainly be aided by multidisciplinary basic research and clinical teams with pharmacology, nanotechnology, neuroscience and pharmaceutic expertise. When successful the end results will provide "optimal" therapeutic delivery platforms. The current report reviews an extensive body of knowledge of the natural history, epidemiology, pathogenesis and therapeutics of neurologic disease with an eye on how, when and under what circumstances neurotheranostics will soon be used as personalized medicines for a broad range of neurodegenerative, neuroinflammatory and neuroinfectious diseases.

Sequential LASER ART and CRISPR Treatments Eliminate HIV-1 in a Subset of Infected Humanized Mice

Elimination of HIV-1 requires clearance and removal of integrated proviral DNA from infected cells and tissues. Here, sequential long-acting slow-effective release antiviral therapy (LASER ART) and CRISPR-Cas9 demonstrate viral clearance in latent infectious reservoirs in HIV-1 infected humanized mice. HIV-1 subgenomic DNA fragments, spanning the long terminal repeats and the Gag gene, are excised in vivo, resulting in elimination of integrated proviral DNA; virus is not detected in blood, lymphoid tissue, bone marrow and brain by nested and digital-droplet PCR as well as RNAscope tests. No CRISPR-Cas9 mediated off-target effects are detected. Adoptive transfer of human immunocytes from dual treated, virus-free animals to uninfected humanized mice fails to produce infectious progeny virus. In contrast, HIV-1 is readily detected following sole LASER ART or CRISPR-Cas9 treatment. These data provide proof-of-concept that permanent viral elimination is possible.

The Promise of Long-Acting Antiretroviral Therapies: From Need to Manufacture

Antiretroviral therapy has transformed human immunodeficiency virus infections from certain death to a manageable chronic disease. Achieving strict adherence to drug regimens that limit toxicities and viral resistance is an achievable goal. Success is defined by halting viral transmission and by continuous viral restriction. A step towards improving treatment outcomes is in long-acting antiretrovirals. While early results remain encouraging there remain opportunities for improvement. These rest, in part, on the required large drug dosing volumes, local injection-site reactions, and frequency of injections. Thus, implantable devices and long-acting parenteral prodrugs have emerged which may provide more effective clinical outcomes. The recent successes in transforming native antiretrovirals into lipophilic and hydrophobic prodrugs stabilized into biocompatible surfactants can positively affect both. Formulating antiretroviral prodrugs demonstrates improvements in cell and tissue targeting, in drug-dosing intervals, and in the administered volumes of nanosuspensions. As such, the newer formulations also hold the potential to suppress viral loads beyond more conventional therapies with the ultimate goal of HIV-1 elimination when combined with other modalities.

In vitro Pharmacokinetic Cell Culture System that Simulates Physiologic Drug and Nanoparticle Exposure to Macrophages

PURPOSE

An in vitro dynamic pharmacokinetic (PK) cell culture system was developed to more precisely simulate physiologic nanoparticle/drug exposure.

METHODS

A dynamic PK cell culture system was developed to more closely reflect physiologic nanoparticle/drug concentrations that are changing with time. Macrophages were cultured in standard static and PK cell culture systems with rifampin (RIF; 5 μg/ml) or β-glucan, chitosan coated, poly(lactic-co-glycolic) acid (GLU-CS-PLGA) nanoparticles (RIF equivalent 5 μg/ml) for 6 h. Intracellular RIF concentrations were measured by UPLC/MS. Antimicrobial activity against M. smegmatis was tested in both PK and static systems.

RESULTS

The dynamic PK cell culture system mimics a one-compartment elimination pharmacokinetic profile to properly mimic in vivo extracellular exposure. GLU-CS-PLGA nanoparticles increased intracellular RIF concentration by 37% compared to free drug in the dynamic cell culture system. GLU-CS-PLGA nanoparticles decreased M. smegmatis colony forming units compared to free drug in the dynamic cell culture system.

CONCLUSIONS

The PK cell culture system developed herein enables more precise simulation of human PK exposure (i.e., drug dosing and drug elimination curves) based on previously obtained PK parameters.

ProTide generated long-acting abacavir nanoformulations

Abacavir pronucleotide nanoformulations (NM3ABC) were prepared as a novel long acting slow effective release antiretroviral therapy. Single NM3ABC treatment of human monocyte-derived macrophages produced sustained intracellular carbovir-triphosphate and antiretroviral activities for up to 30 days.

Nanoparticle-in-microparticle oral drug delivery system of a clinically relevant darunavir/ritonavir antiretroviral combination

Nanonizationhas been extensively investigated to increase theoral bioavailability of hydrophobicdrugsin general andantiretrovirals(ARVs)used inthe therapy of the human immunodeficiency virus (HIV) infection in particular. Weanticipatedthatin the caseofprotease inhibitors, a family of pH-dependent ARVsthatdisplay high aqueous solubility undertheacidconditionsof thestomach andextremely low solubilityunder the neutral ones ofthe small intestine, this strategy might failowing to an uncontrolled dissolution-re-precipitation process that will take place along the gastrointestinal tract.To tackle thisbiopharmaceutical challenge, in this work, wedesigned, produced and fully characterized a novelNanoparticle-in-MicroparticleDelivery System(NiMDS)comprised of pure nanoparticlesofthefirst-line protease inhibitor darunavir(DRV) and itsboosting agentritonavir (RIT) encapsulated within film-coated microparticles.For this, a clinically relevant combination of pure DRV and RIT nanoparticles wassynthesized by a sequential nanoprecipitation/solvent diffusion and evaporation method employing sodium alginateas viscosity stabilizer. Then, pure nanoparticles were encapsulated within calcium alginate/chitosanmicroparticlesthat were film-coated with a series ofpoly(methacrylate) copolymers with differential solubility in the gastrointestinal tract. This coating ensured full stability under gastric-like pH and sustained drug release under intestinal one. PharmacokineticstudiesconductedinalbinoSpragueDawleyratsshowed that DRV/RIT-loadedNiMDSs containing 17% w/w drug loading based on dry weight significantlyincreasedthe oral bioavailabilityof DRVby 2.3-foldwith respect to both theunprocessedandthenanonized DRV/RIT combinations that showed statistically similar performance. Moreover, they highlighted the limited advantage of only drugnanonizationto improve the oral pharmacokinetics of protease inhibitors and the potential of our novel delivery approach to improve the oral pharmacokinetics of nanonized poorly water-soluble drugs displaying pH-dependent solubility.

STATEMENT OF SIGNIFICANCE

Protease inhibitors (PIs) are gold-standard drugs in many ARV cocktails. Darunavir (DRV) is the latest approved PI and it is included in the 20th WHO Model List of Essential Medicines. PIs poorly-water soluble at intestinal pH and more soluble under gastric conditions. Drug nanonization represents one of the most common nanotechnology strategies to increase dissolution rate of hydrophobic drugs and thus, their oral bioavailability. For instance, pure drug nanosuspensions became the most clinically relevant nanoformulation. However, according to the physicochemical properties of PIs, nanonization does not appear as a very beneficial strategy due to the fast dissolution rate anticipated under the acid conditions of the stomach and their uncontrolled recrystallization and precipitation in the small intestine that might result in the formation of particles of unpredictable size and structure (e.g., crystallinity and polymorphism) and consequently, unknown dissolution rate and bioavailability. In this work, we developed a sequential nanoprecipitation method for the production of pure nanoparticles of DRV and its boosting agent ritonavir in a clinically relevant 8:1 wt ratio using alginate as viscosity stabilizer and used this nanosuspension to produce a novel kind of nanoparticle-in-microparticle delivery system that was fully characterized and the pharmacokinetics assessed in rats. The most significant points of the current manuscript are.