Albumin-based drug delivery as novel therapeutic approach for rheumatoid arthritis

Single-Domain Antibodies as Antibody-Drug Conjugates: From Promise to Practice-A Systematic Review

BACKGROUND

Antibody-drug conjugates (ADCs) represent potent cancer therapies that deliver highly toxic drugs to tumor cells precisely, thus allowing for targeted treatment and significantly reducing off-target effects. Despite their effectiveness, ADCs can face limitations due to acquired resistance and potential side effects.

OBJECTIVES

This study focuses on advances in various ADC components to improve both the efficacy and safety of these agents, and includes the analysis of several novel ADC formats. This work assesses whether the unique features of VHHs-such as their small size, enhanced tissue penetration, stability, and cost-effectiveness-make them a viable alternative to conventional antibodies for ADCs and reviews their current status in ADC development.

METHODS

Following PRISMA guidelines, this study focused on VHHs as components of ADCs, examining advancements and prospects from 1 January 2014 to 30 June 2024. Searches were conducted in PubMed, Cochrane Library, ScienceDirect and LILACS using specific terms related to ADCs and single-domain antibodies. Retrieved articles were rigorously evaluated, excluding duplicates and non-qualifying studies. The selected peer-reviewed articles were analyzed for quality and synthesized to highlight advancements, methods, payloads, and future directions in ADC research.

RESULTS

VHHs offer significant advantages for drug conjugation over conventional antibodies due to their smaller size and structure, which enhance tissue penetration and enable access to previously inaccessible epitopes. Their superior stability, solubility, and manufacturability facilitate cost-effective production and expand the range of targetable antigens. Additionally, some VHHs can naturally cross the blood-brain barrier or be easily modified to favor their penetration, making them promising for targeting brain tumors and metastases. Although no VHH-drug conjugates (nADC or nanoADC) are currently in the clinical arena, preclinical studies have explored various conjugation methods and linkers.

CONCLUSIONS

While ADCs are transforming cancer treatment, their unique mechanisms and associated toxicities challenge traditional views on bioavailability and vary with different tumor types. Severe toxicities, often linked to compound instability, off-target effects, and nonspecific blood cell interactions, highlight the need for better understanding. Conversely, the rapid distribution, tumor penetration, and clearance of VHHs could be advantageous, potentially reducing toxicity by minimizing prolonged exposure. These attributes make single-domain antibodies strong candidates for the next generation of ADCs, potentially enhancing both efficacy and safety.

Albumin Nanoparticle-Based Drug Delivery Systems

Nanoparticle-based systems are extensively investigated for drug delivery. Among others, with superior biocompatibility and enhanced targeting capacity, albumin appears to be a promising carrier for drug delivery. Albumin nanoparticles are highly favored in many disease therapies, as they have the proper chemical groups for modification, cell-binding sites for cell adhesion, and affinity to protein drugs for nanocomplex generation. Herein, this review summarizes the recent fabrication techniques, modification strategies, and application of albumin nanoparticles. We first discuss various albumin nanoparticle fabrication methods, from both pros and cons. Then, we provide a comprehensive introduction to the modification section, including organic albumin nanoparticles, metal albumin nanoparticles, inorganic albumin nanoparticles, and albumin nanoparticle-based hybrids. We finally bring further perspectives on albumin nanoparticles used for various critical diseases.

Characterization and humanization of VNARs targeting human serum albumin from the whitespotted bamboo shark (Chiloscyllium plagiosum)

The Shark-derived immunoglobulin new antigen receptors (IgNARs) have gained increasing attention for their high solubility, exceptional thermal stability, and intricate sequence variation. In this study, we immunized whitespotted bamboo shark (Chiloscyllium plagiosum) to create phage display library of variable domains of IgNAR (VNARs) for screening against Human Serum Albumin (HSA), a versatile vehicle in circulation due to its long in vivo half-life. We identified two HSA-binding VNAR clones, 2G5 and 2G6, and enhanced their expression in E. coli with the FKPA chaperone. 2G6 exhibited a strong binding affinity of 13 nM with HSA and an EC50 of 1 nM. In vivo study with a murine model further provided initial validation of 2G6's ability to prolong circulation time by binding to HSA. Additionally, we employed computational molecular docking to predict the binding affinities of both 2G6 and its humanized derivative, H2G6, to HSA. Our analysis unveiled that the complementarity-determining regions (CDR1 and CDR3) are pivotal in the antigen recognition process. Therefore, our study has advanced the understanding of the potential applications of VNARs in biomedical research aimed at extending drug half-life, holding promise for future therapeutic and diagnostic progressions.

Evaluation of the prognostic nutritional index (PNI) as a tool for assessing disease activity in rheumatoid arthritis patients

OBJECTIVES

Rheumatoid arthritis (RA) is an autoimmune disease of unknown exact cause, characterized by chronic inflammation. The prognostic nutritional index (PNI), reflecting albumin concentration and lymphocyte count, is a newly established inflammation-based nutritional score. This study aimed to determine the relationship between PNI and disease activity in RA patients.

PATIENTS AND METHODS

This cross-sectional study included 138 RA patients who met the 2010 revised criteria of the American College of Rheumatology (ACR) for RA. PNI was calculated using the following formula: 10 × serum albumin value (g/dL) + 0.005 × total lymphocyte count in the peripheral blood (per mm3). The study population was divided into two groups: DAS28-ESR ≤ 3.2 (group 1 with remission and low disease activity) and DAS28-ESR > 3.2 (group 2 with moderate and high disease activity).

RESULTS

A total of 138 patients with a mean age of 52.1 years were recruited. While the female gender was more prevalent in both groups, it was significantly higher in group 2 (p < 0.05). Group 2 exhibited a lower PNI compared to those in group 1 (42.17 ± 3.46 vs. 44.02 ± 2.92; p = 0.001). Multivariate logistic regression analyses revealed that PNI was an independent predictor of disease activity (OR, 0.850; 95% CI, 0.735-0.983; p = 0.029). ROC curve analysis determined that the optimal cutoff value of PNI for disease activity was 43.01, with a sensitivity of 69.1% and specificity of 57.7% (AUC, 0.66; 95% CI, 0.57-0.75, p = 0.001).

CONCLUSION

This study demonstrates that the simple and readily available PNI could serve as an independent predictor of disease activity in rheumatoid arthritis patients. Key Points •The relationship between disease activity and the prognostic nutritional index, which is a nutritional indicator, in rheumatoid arthritis patients was investigated. •It has been shown that there is a connection between low PNI and high disease activity. •It has been shown that PNI can be used to evaluate disease severity with a simple calculation.

Prodrug-based nanomedicines for rheumatoid arthritis

Most antirheumatic drugs with high toxicity exhibit a narrow therapeutic window due to their nonspecific distribution in the body, leading to undesirable side effects and reduced patient compliance. To in response to these challenges, prodrug-based nanoparticulate drug delivery systems (PNDDS), which combines prodrug strategy and nanotechnology into a single system, resulting their many advantages, including stability for prodrug structure, the higher drug loading capacity of the system, improving the target activity and bioavailability, and reducing their untoward effects. PNDDS have gained attention as a method for relieving arthralgia syndrome of rheumatoid arthritis in recent years. This article systematically reviews prodrug-based nanocarriers for rheumatism treatment, including Nano systems based on prodrug-encapsulated nanomedicines and conjugate-based nanomedicines. It provides a new direction for the clinical treatment of rheumatoid arthritis.

Use of Albumin for Drug Delivery as a Diagnostic and Therapeutic Tool

Drug delivery is an important topic that has attracted the attention of researchers in recent years. Albumin nanoparticles play a significant role in drug delivery as a carrier due to their unique characteristics. Albumin is non-toxic, biocompatible, and biodegradable. Its structure is such that it can interact with different drugs, which makes the treatment of the disease faster and also reduces the side effects of the drug. Albumin nanoparticles can be used in the diagnosis and treatment of many diseases, including cancer, diabetes, Alzheimer's, etc. These nanoparticles can connect to some compounds, such as metal nanoparticles, antibodies, folate, etc. and create a powerful nanostructure for drug delivery. In this paper, we aim to investigate albumin nanoparticles in carrier format for drug delivery application. In the beginning, different types of albumin and their preparation methods were discussed, and then albumin nanoparticles were discussed in detail in diagnosing and treating various diseases.

Albumin-binding RNAi Conjugate for Carrier Free Treatment of Arthritis

Osteoarthritis (OA) and rheumatoid arthritis (RA) are joint diseases that are associated with pain and lost quality of life. No disease modifying OA drugs are currently available. RA treatments are better established but are not always effective and can cause immune suppression. Here, an MMP13-selective siRNA conjugate was developed that, when delivered intravenously, docks onto endogenous albumin and promotes preferential accumulation in articular cartilage and synovia of OA and RA joints. MMP13 expression was diminished upon intravenous delivery of MMP13 siRNA conjugates, consequently decreasing multiple histological and molecular markers of disease severity, while also reducing clinical manifestations such as swelling (RA) and joint pressure sensitivity (RA and OA). Importantly, MMP13 silencing provided more comprehensive OA treatment efficacy than standard of care (steroids) or experimental MMP inhibitors. These data demonstrate the utility of albumin 'hitchhiking' for drug delivery to arthritic joints, and establish the therapeutic utility of systemically delivered anti-MMP13 siRNA conjugates in OA and RA.

Editorial summary

Lipophilic siRNA conjugates optimized for albumin binding and "hitchhiking" can be leveraged to achieve preferential delivery to and gene silencing activity within arthritic joints. Chemical stabilization of the lipophilic siRNA enables intravenous siRNA delivery without lipid or polymer encapsulation. Using siRNA sequences targeting MMP13, a key driver of arthritis-related inflammation, albumin hitchhiking siRNA diminished MMP13, inflammation, and manifestations of osteoarthritis and rheumatoid arthritis at molecular, histological, and clinical levels, consistently outperforming clinical standards of care and small molecule MMP antagonists.

Biomimetic nanomedicines for precise atherosclerosis theranostics

Atherosclerosis (AS) is a leading cause of the life-threatening cardiovascular disease (CVD), creating an urgent need for efficient, biocompatible therapeutics for diagnosis and treatment. Biomimetic nanomedicines (bNMs) are moving closer to fulfilling this need, pushing back the frontier of nano-based drug delivery systems design. This review seeks to outline how these nanomedicines (NMs) might work to diagnose and treat atherosclerosis, to trace the trajectory of their development to date and in the coming years, and to provide a foundation for further discussion about atherosclerotic theranostics.

Recent Advancements and Strategies for Overcoming the Blood-Brain Barrier Using Albumin-Based Drug Delivery Systems to Treat Brain Cancer, with a Focus on Glioblastoma

Glioblastoma multiforme (GBM) is a highly aggressive malignant tumor, and the most prevalent primary malignant tumor affecting the brain and central nervous system. Recent research indicates that the genetic profile of GBM makes it resistant to drugs and radiation. However, the main obstacle in treating GBM is transporting drugs through the blood-brain barrier (BBB). Albumin is a versatile biomaterial for the synthesis of nanoparticles. The efficiency of albumin-based delivery systems is determined by their ability to improve tumor targeting and accumulation. In this review, we will discuss the prevalence of human glioblastoma and the currently adopted treatment, as well as the structure and some essential functions of the BBB, to transport drugs through this barrier. We will also mention some aspects related to the blood-tumor brain barrier (BTBB) that lead to poor treatment efficacy. The properties and structure of serum albumin were highlighted, such as its role in targeting brain tumors, as well as the progress made until now regarding the techniques for obtaining albumin nanoparticles and their functionalization, in order to overcome the BBB and treat cancer, especially human glioblastoma. The albumin drug delivery nanosystems mentioned in this paper have improved properties and can overcome the BBB to target brain tumors.

Izokibep for the treatment of moderate-to-severe plaque psoriasis: a phase II, randomized, placebo-controlled, double-blind, dose-finding multicentre study including long-term treatment

BACKGROUND

Monoclonal antibodies to interleukin (IL)-17 have shown strong efficacy in patients with psoriasis. Izokibep is a unique IL-17A inhibitor with a small molecular size and favourable distribution to sites of inflammation.

OBJECTIVES

To evaluate the dose response, efficacy and safety of izokibep in patients with plaque psoriasis.

METHODS

In this double-blind, randomized, phase II dose-finding study (AFFIRM-35) in adults with moderate-to-severe plaque psoriasis and inadequate response to two or more standard therapies, patients were randomized (1:1:1:1:1) to placebo or izokibep 2, 20, 80 or 160 mg every 2 weeks for 12 weeks. During the remainder of the 52-week core study, patients given placebo were switched to izokibep 80 mg, and dosing intervals were adapted based on Psoriasis Area and Severity Index (PASI) scores for all patients. The core study was followed by two optional consecutive 1-year extension periods for a total duration of 3 years. The primary endpoint was a 90% reduction in PASI score (PASI 90) at week 12. Additional efficacy outcomes and adverse event (AE) rates were evaluated.

RESULTS

In total, 109 patients were randomized [safety set, n = 108 (one exclusion criteria failure); full analysis set, n = 106]. At week 12, PASI 90 response rates were 0%, 5%, 19%, 71% and 59% for the placebo, 2-, 20-, 80- and 160-mg izokibep groups, respectively. Rapid dose-dependent improvements were also observed across other efficacy outcomes. During the placebo-controlled period, AEs in the izokibep groups were similar to placebo except for mild injection site reactions. AEs were generally mild to moderate and the drug was well tolerated. Izokibep maintained efficacy at the higher dosage groups for up to 3 years, with no new safety signals.

CONCLUSIONS

Data from this phase II study indicate that izokibep is well tolerated and efficacious in the treatment of plaque psoriasis. Higher doses or more frequent dosing could be explored to further enhance response rates.

Efficacy and safety of anti-TNF multivalent NANOBODY® compound 'ozoralizumab' without methotrexate co-administration in patients with active rheumatoid arthritis: A 52-week result of phase III, randomised, open-label trial (NATSUZORA trial)

OBJECTIVES

The aim is to assess the efficacy and safety of a 52-week subcutaneous ozoralizumab treatment at 30 and 80 mg without methotrexate (MTX) in active rheumatoid arthritis.

METHODS

This randomised, open-label, multicentre phase III trial randomly allocated 140 patients in 2:1 ratio as subcutaneous ozoralizumab at 30 or 80 mg every 4 weeks for 52 weeks without MTX.

RESULTS

Both groups administered ozoralizumab at 30 and 80 mg showed good clinical improvement. The American College of Rheumatology response rates were high at Week 24 and maintained through 52 weeks. The ozoralizumab groups also showed good improvement in other end points, and improvements observed from Week 1 were maintained through 52 weeks. Improvements in many efficacy assessments were similar between doses. No deaths were reported, and serious adverse events occurred in a total of 20 patients in the ozoralizumab groups. Increased antidrug antibodies were observed in approximately 40% of patients in the ozoralizumab groups, and 27.7% of the patients in the 30 mg group were neutralising antibody-positive.

CONCLUSIONS

Ozoralizumab, at 30 and 80 mg, demonstrated significant therapeutic effects without MTX, and the efficacy was maintained for 52 weeks with active rheumatoid arthritis. Ozoralizumab showed an acceptable tolerability profile over 52 weeks.

Efficacy and safety of the anti-TNF multivalent NANOBODY® compound ozoralizumab in patients with rheumatoid arthritis and an inadequate response to methotrexate: A 52-week result of a Phase II/III study (OHZORA trial)

OBJECTIVE

To assess the efficacy and safety through a 52-week treatment with subcutaneous ozoralizumab at 30 or 80 mg in patients with active rheumatoid arthritis despite methotrexate therapy.

METHODS

This multicentre, randomized, placebo-controlled, double-blind, parallel-group confirmatory trial included a 24-week double-blind treatment period followed by a 28-week open-label treatment period. The double-blind treatment period randomized 381 (2:2:1) patients to placebo and ozoralizumab at 30 or 80 mg, and patients receiving placebo were re-randomized (1:1) to ozoralizumab at 30 or 80 mg in the open-label period.

RESULTS

The ozoralizumab groups showed good clinical improvement, with high American College of Rheumatology response rates at 52 weeks, as well as good improvements in other endpoints, which were observed from Day 3 and maintained through Week 52. Furthermore, the ozoralizumab groups showed a high remission rate in clinical and functional remission at Week 52. Serious adverse events occurred in a total of 23 patients in the ozoralizumab groups, without differences in incidence between doses.

CONCLUSIONS

Ozoralizumab demonstrated significant therapeutic effects and efficacy, which was maintained for 52 weeks. The safety profile was consistent with the evaluated results in interim analysis at Week 24, and ozoralizumab was well-tolerated up to Week 52.

NANOBODY® Molecule, a Giga Medical Tool in Nanodimensions

Although antibodies remain the most widely used tool for biomedical research, antibody technology is not flawless. Innovative alternatives, such as Nanobody® molecules, were developed to address the shortcomings of conventional antibodies. Nanobody® molecules are antigen-binding variable-domain fragments derived from the heavy-chain-only antibodies of camelids (VHH) and combine the advantageous properties of small molecules and monoclonal antibodies. Nanobody® molecules present a small size (~15 kDa, 4 nm long and 2.5 nm wide), high solubility, stability, specificity, and affinity, ease of cloning, and thermal and chemical resistance. Recombinant production in microorganisms is cost-effective, and VHH are also building blocks for multidomain constructs. These unique features led to numerous applications in fundamental research, diagnostics, and therapy. Nanobody® molecules are employed as biomarker probes and, when fused to radioisotopes or fluorophores, represent ideal non-invasive in vivo imaging agents. They can be used as neutralizing agents, receptor-ligand antagonists, or in targeted vehicle-based drug therapy. As early as 2018, the first Nanobody®, Cablivi (caplacizumab), a single-domain antibody (sdAb) drug developed by French pharmaceutical giant Sanofi for the treatment of adult patients with acquired thrombocytopenic purpura (aTTP), was launched. Nanobody® compounds are ideal tools for further development in clinics for diagnostic and therapeutic purposes.

Izokibep: Preclinical development and first-in-human study of a novel IL-17A neutralizing Affibody molecule in patients with plaque psoriasis

Psoriasis, an immune-mediated inflammatory disease, affects nearly 125 million people globally. The interleukin (IL)-17A homodimer is a key driver of psoriasis and other autoimmune diseases, including psoriatic arthritis, axial spondyloarthritis, hidradenitis suppurativa, and uveitis. Treatment with monoclonal antibodies (mAbs) against IL-17A provides an improvement in the Psoriasis Area and Severity Index compared to conventional systemic agents. In this study, the AffibodyⓇ technology was used to identify and optimize a novel, small, biological molecule comprising three triple helical affinity domains, izokibep (previously ABY-035), for the inhibition of IL-17A signaling. Preclinical studies show that izokibep, a small 18.6 kDa IL-17 ligand trap comprising two IL-17A-specific Affibody domains and one albumin-binding domain, selectively inhibits human IL-17A in vitro and in vivo with superior potency and efficacy relative to anti-IL-17A mAbs. A Phase 1 first-in-human study was conducted to establish the safety, pharmacokinetics, and preliminary efficacy of izokibep, when administered intravenously and subcutaneously as single doses to healthy subjects, and as single intravenous and multiple subcutaneous doses to patients with psoriasis (NCT02690142; EudraCT No: 2015-004531-13). Izokibep was well tolerated with no meaningful safety concerns identified in healthy volunteers and patients with psoriasis. Rapid efficacy was seen in all psoriasis patients after one dose which further improved in patients receiving multiple doses. A therapeutic decrease in joint pain was also observed in a single patient with concurrent psoriatic arthritis. The study suggests that izokibep has the potential to safely treat IL17A-associated diseases such as psoriasis, psoriatic arthritis, axial spondyloarthritis, hidradenitis suppurativa, and uveitis.

Advanced EPI-X4 Derivatives Covalently Bind Human Serum Albumin Resulting in Prolonged Plasma Stability

Advanced derivatives of the Endogenous Peptide Inhibitor of CXCR4 (EPI-X4) have shown therapeutic efficacy upon topical administration in animal models of asthma and dermatitis. Here, we studied the plasma stability of the EPI-X4 lead compounds WSC02 and JM#21, using mass spectrometry to monitor the chemical integrity of the peptides and a functional fluorescence-based assay to determine peptide function in a CXCR4-antibody competition assay. Although mass spectrometry revealed very rapid disappearance of both peptides in human plasma within seconds, the functional assay revealed a significantly higher half-life of 9 min for EPI-X4 WSC02 and 6 min for EPI-X4 JM#21. Further analyses demonstrated that EPI-X4 WSC02 and EPI-X4 JM#21 interact with low molecular weight plasma components and serum albumin. Albumin binding is mediated by the formation of a disulfide bridge between Cys10 in the EPI-X4 peptides and Cys34 in albumin. These covalently linked albumin-peptide complexes have a higher stability in plasma as compared with the non-bound peptides and retain the ability to bind and antagonize CXCR4. Remarkably, chemically synthesized albumin-EPI-X4 conjugates coupled by non-breakable bonds have a drastically increased plasma stability of over 2 h. Thus, covalent coupling of EPI-X4 to albumin in vitro before administration or in vivo post administration may significantly increase the pharmacokinetic properties of this new class of CXCR4 antagonists.

Biologic Evaluation of a Heterodimeric HER2-Albumin Targeted Affibody Molecule Produced by Chemo-Enzymatic Peptide Synthesis

Targeted molecular radiation therapy is a promising emerging treatment modality in oncology, and peptide synthesis may shorten the time to reach the clinical stage. In this study, we have explored Chemo-Enzymatic Peptide Synthesis, or CEPS, as a new means of producing a therapeutic HER2 targeted Affibody^® molecule, comprising a C-terminal albumin binding domain (ABD) for half-life extension and a total length of 108 amino acids. In addition, a DOTA moiety could be incorporated at N-terminus directly during the synthesis step and subsequently utilized for site-specific radiolabeling with the therapeutic radionuclide ¹⁷⁷Lu. Retained thermodynamic stability as well as retained binding to both HER2 and albumin was verified. Furthermore, HER2 binding specificity of the radiolabeled Affibody molecule was confirmed by an in vitro saturation assay showing a significantly higher cell-bound activity of SKOV-3 (high HER2 expression) compared with BxPC3 (low HER2 expression), both in the presence and absence of HSA. In vivo evaluation in mice bearing HER2 expressing xenografts also showed specific tumor targeting as well as extended time in circulation and reduced kidney uptake compared with a HER2 targeted Affibody molecule without the ABD moiety. To conclude, we have demonstrated that CEPS can be used for production of Affibody-fusion molecules with retained in vitro and in vivo functionality.

Phase II/III Results of a Trial of Anti-Tumor Necrosis Factor Multivalent NANOBODY Compound Ozoralizumab in Patients With Rheumatoid Arthritis

OBJECTIVE

To assess the efficacy and safety of subcutaneous administration of 30 mg or 80 mg of ozoralizumab plus methotrexate (MTX) in patients with rheumatoid arthritis (RA) whose disease remained active despite MTX therapy.

METHODS

In this multicenter, double-blind, parallel-group, placebo-controlled phase II/III trial, 381 patients were randomized to receive placebo, ozoralizumab 30 mg, or ozoralizumab 80 mg, plus MTX subcutaneously injected every 4 weeks for 24 weeks. The primary end points were the response rates based on the American College of Rheumatology 20% improvement criteria (ACR20) at week 16 and change in the Sharp/van der Heijde score (ΔSHS) from baseline to week 24.

RESULTS

The proportion of patients with an ACR20 response at week 16 was significantly higher (P < 0.001) in both ozoralizumab groups (79.6% for 30 mg, 75.3% for 80 mg), compared with placebo (37.3%); these improvements were observed from the first week of treatment. The proportion of the patients with structural nonprogression (ΔSHS ≤0) was significantly higher in both ozoralizumab groups than in the placebo group. For some secondary end points, significantly greater improvements were observed starting from as early as day 3. Serious adverse events occurred in 4 patients in the ozoralizumab 30-mg group and 5 patients in the ozoralizumab 80-mg group.

CONCLUSION

In patients with active RA who received ozoralizumab in combination with MTX, the signs and symptoms of RA were significantly reduced as compared with the outcomes in those receiving placebo. Ozoralizumab demonstrated acceptable tolerability with no new safety signals when compared with other antibodies against tumor necrosis factor.

A novel anti-TNF-α drug ozoralizumab rapidly distributes to inflamed joint tissues in a mouse model of collagen induced arthritis

In clinical studies, the next-generation anti-tumor necrosis factor-alpha (TNF-α) single domain antibody ozoralizumab showed high clinical efficacy shortly after the subcutaneous injection. To elucidate the mechanism underlying the rapid onset of the effects of ozoralizumab, we compared the biodistribution kinetics of ozoralizumab and adalimumab after subcutaneous injection in an animal model of arthritis. Alexa Fluor 680-labeled ozoralizumab and adalimumab were administered by subcutaneous injection once (2 mg/kg) at five weeks after induction of collagen-induced arthritis (CIA) in an animal arthritis model. The time-course of changes in the fluorescence intensities of the two compounds in the paws and serum were evaluated. The paws of the CIA mice were harvested at four and eight hours after the injection for fluorescence microscopy. Biofluorescence imaging revealed better distribution of ozoralizumab to the joint tissues than of adalimumab, as early as at four hours after the injection. Fluorescence microscopy revealed a greater fluorescence intensity of ozoralizumab in the joint tissues than that of adalimumab at eight hours after the injection. Ozoralizumab showed a significantly higher absorption rate constant as compared with adalimumab. These results indicate that ozoralizumab enters the systemic circulation more rapidly and is distributed to the target tissues earlier and at higher levels than conventional IgG antibodies. Our investigation provides new insight into the mechanism underlying the rapid onset of the effects of ozoralizumab in clinical practice.

Films, Gels and Electrospun Fibers from Serum Albumin Globular Protein for Medical Device Coating, Biomolecule Delivery and Regenerative Engineering

Albumin is a natural biomaterial that is abundantly available in blood and body fluids. It is clinically used as a plasma expander, thereby increasing the plasma thiol concentration due to its cysteine residues. Albumin is a regulator of intervascular oncotic pressure, serves as an anti-inflammatory modulator, and it has a buffering role due to its histidine imidazole residues. Because of its unique biological and physical properties, albumin has also emerged as a suitable biomaterial for coating implantable devices, for cell and drug delivery, and as a scaffold for tissue engineering and regenerative medicine. As a biomaterial, albumin can be used as surface-modifying film or processed either as cross-linked protein gels or as electrospun fibers. Herein we have discussed how albumin protein can be utilized in regenerative medicine as a hydrogel and as a fibrous mat for a diverse role in successfully delivering drugs, genes, and cells to targeted tissues and organs. The review of prior studies indicated that albumin is a tunable biomaterial from which different types of scaffolds with mechanical properties adjustable for various biomedical applications can be fabricated. Based on the progress made to date, we concluded that albumin-based device coatings, delivery of drugs, genes, and cells are promising strategies in regenerative and personalized medicine.

Recent progress in therapeutic strategies and biomimetic nanomedicines for rheumatoid arthritis treatment

INTRODUCTION

Rheumatoid arthritis (RA) is an autoimmune systemic disease in which inflammatory and immune cells accumulate in inflamed joints. Researchers aimed at the characteristics of RA to achieve the effect of treating RA through different therapeutic strategies, and have used various endogenous materials to design drug-loaded nanoparticles that can target RA by binding to cell adhesion molecules or chemokines. In some cases, the nanoparticles can respond to the characteristics of the microenvironment.

AREAS COVERED

This article reviews the recent advances in the treatment of RA from two aspects of therapeutic strategies and delivery strategies. Therapeutic strategies mainly include neutralization of inflammatory factors, promotion of inflammatory cell apoptosis, ROS scavenger, immunosuppression, and bone tissue repair. The drug delivery strategy is mainly described from two aspects: chemically functionalized biomimetic nanoparticles and endogenous nanoparticles.

EXPERT OPINION

Biomimetic NPs may be effective drug carriers for targeted RA treatment. NPs can reduce the clearance of mononuclear phagocytes, prolong the blood circulation time, and improve the targeting ability. With the deepening of research, more and more biomimetic NPs have entered the clinical trial stage. However, safe and scalable preparation methods are needed to improve their clinical applicability.

Nanoparticle Properties Influence Transendothelial Migration of Monocytes

Nanoparticle-based delivery of therapeutics to the brain has had limited clinical impact due to challenges crossing the blood-brain barrier (BBB). Certain cells, such as monocytes, possess the ability to migrate across the BBB, making them attractive candidates for cell-based brain delivery strategies. In this work, we explore nanoparticle design parameters that impact both monocyte association and monocyte-mediated BBB transport. We use electrohydrodynamic jetting to prepare nanoparticles of varying sizes, compositions, and elasticity to address their impact on uptake by THP-1 monocytes and permeation across the BBB. An in vitro human BBB model is developed using human cerebral microvascular endothelial cells (hCMEC/D3) for the assessment of migration. We compare monocyte uptake of both polymeric and synthetic protein nanoparticles (SPNPs) of various sizes, as well as their effect on cell migration. SPNPs (human serum albumin/HSA or human transferrin/TF) are shown to promote increased monocyte-mediated transport across the BBB over polymeric nanoparticles. TF SPNPs (200 nm) associate readily, with an average uptake of 138 particles/cell. Nanoparticle loading is shown to influence the migration of THP-1 monocytes. The migration of monocytes loaded with 200 nm TF and 200 nm HSA SPNPs was 2.3-fold and 2.1-fold higher than that of an untreated control. RNA-seq analysis after TF SPNP treatment suggests that the upregulation of several migration genes may be implicated in increased monocyte migration (ex. integrin subunits α M and α L). Integrin β 2 chain combines with either integrin subunit α M chain or integrin subunit α L chain to form macrophage antigen 1 and lymphocyte function-associated antigen 1 integrins. Both products play a pivotal role in the transendothelial migration cascade. Our findings highlight the potential of SPNPs as drug and/or gene delivery platforms for monocyte-mediated BBB transport, especially where conventional polymer nanoparticles are ineffective or otherwise not desirable.

Albumin Binds Doxorubicin via Self−Assembling Dyes as Specific Polymolecular Ligands

Congo red (CR) type self–assembled ribbon–like structures (SRLS) were previously shown to interact with some proteins, including albumin. SRLS also complex with some drugs with a flat, ring–shaped structure with aromatic characteristics, intercalating them into their ribbon structure. The combination of interaction with proteins and drug binding by SRLS enables the use of such systems for immunotargeting. It is especially interesting in the case of chemotherapeutic agents. The present experiments aimed to show that the model carrier system composed of supramolecular albumin and Congo red efficiently binds doxorubicin (Dox) and that the drug can be released at reduced pH. The presented results come from the studies on such complexes differing in the molar ratio of CR to Dox. The following methods were used for the analysis: electrophoresis, dialysis, gel filtration, spectral analysis, and analysis of the size of the hydrodynamic radius using the dynamic light scattering method (DLS). The applied methods confirmed the formation of the CR–Dox complex, with large dimensions and changed properties compared with free CR. The presented results show that albumin binds both CR and its complex with Dox. Various CR–Dox molar ratios, 5:1, 2:1, and 1:1, were analyzed. The confirmation of the possibility of releasing the drug from the carriers thus formed was also obtained. The presented research is important due to the search for optimal solutions for the use of SRLS in drug immunotargeting, with particular emphasis on chemotherapeutic agents.

Characterizing the pharmacokinetics and biodistribution of therapeutic proteins: an industry white paper

Characterization of the pharmacokinetics (PK) and biodistribution of therapeutic proteins (TPs) is a hot topic within the pharmaceutical industry, particularly with an ever-increasing catalog of novel modality TPs. Here, we review the current practices, and provide a summary of extensive cross-company discussions as well as a survey completed by International Consortium for Innovation and Quality (IQ consortium) members on this theme. A wide variety of in vitro, in vivo and in silico techniques are currently used to assess PK and biodistribution of TPs, and we discuss the relevance of these from an industry perspective, focusing on PK/PD understanding at the preclinical stage of development, and translation to human. We consider that the 'traditional in vivo biodistribution study' is becoming insufficient as a standalone tool, and thorough characterization of the interaction of the TP with its target(s), target biology, and off-target interactions at a microscopic scale are key to understand the overall biodistribution at a full-body scale. Our summary of the current challenges and our recommendations to address these issues could provide insight into the implementation of best practices in this area of drug development, and continued cross-company collaboration will be of tremendous value. Significance Statement The Innovation & Quality Consortium (IQ) Translational and ADME Sciences Leadership Group (TALG) working group for the ADME of therapeutic proteins evaluates the current practices, recent advances, and challenges in characterizing the PK and biodistribution of therapeutic proteins during drug development, and proposes recommendations to address these issues. Incorporating the in vitro, in vivo and in silico approaches discussed herein may provide a pragmatic framework to increase early understanding of PK/PD relationships, and aid translational modelling for first-in-human dose predictions.

Molecular Dynamics Study of Citrullinated Proteins Associated with the Development of Rheumatoid Arthritis

Biological activity regulation by protein post-translational modification (PTM) is critical for cell function, development, differentiation, and survival. Dysregulation of PTM proteins is present in various pathological conditions, including rheumatoid arthritis (RA). RA is a systemic autoimmune disease that primarily affects joints, and there are three main types of protein PTMs associated with the development of this disease, namely, glycosylation, citrullination, and carbamylation. Glycosylation is important for the processing and presentation of antigen fragments on the cell surface and can modulate immunoglobulin activity. The citrullination of autoantigens is closely associated with RA, as evidenced by the presence of antibodies specific to citrullinated proteins in the serum of patients. Carbamylation and dysregulation have recently been associated with RA development in humans.In this study, we performed an overview analysis of proteins with post-translational modifications associated with the development of RA adverted in peer-reviewed scientific papers for the past 20 years. As a result of the search, a list of target proteins and corresponding amino acid sequences with PTM in RA was formed. Structural characteristics of the listed modified proteins were extracted from the Protein Data Bank. Then, molecular dynamics experiments of intact protein structures and corresponding structures with PTMs were performed regarding structures in the list announced in the ProtDB service. This study aimed to conduct a molecular dynamics study of intact proteins and proteins, including post-translational modification and protein citrullination, likely associated with RA development. We observed another exhibition of the fundamental physics concept, symmetry, at the submolecular level, unveiled as the autonomous repetitions of outside the protein structural motif performance globule corresponding to those in the whole protein molecule.

Stimulus-Responsive Nanoconjugates Derived from Phytoglycogen Nanoparticles

Plant-derived phytoglycogen nanoparticles (PhG NPs) have the advantages of size uniformity, dispersibility in water, excellent lubrication properties, and lack of cytotoxicity; however, their chemical functionalization may lead to loss of NP structural integrity. Here, we report a straightforward approach to the generation of PhG NP conjugates with biologically active molecules. Hydrogen bonding of bovine serum albumin with electroneutral PhG NPs endows them with additional ligand binding affinity and enables the electrostatically governed attachment of methotrexate (MTX), a therapeutic agent commonly used in the treatment of cancer and arthritis diseases, to the protein-capped NPs. We showed stimuli-responsive release of MTX from the PhG-based nanoconjugates under physiological cues such as temperature and ionic strength. The results of this study stimulate future exploration of biomedical applications of nanoconjugates of PhG NPs.

Pharmacokinetic Engineering of OX40-Blocking Anticalin Proteins Using Monomeric Plasma Half-Life Extension Domains

Anticalin^® proteins have been proven as versatile clinical stage biotherapeutics. Due to their small size (∼20 kDa), they harbor a short intrinsic plasma half-life which can be extended, e.g., by fusion with IgG or Fc. However, for antagonism of co-immunostimulatory Tumor Necrosis Factor Receptor Superfamily (TNFRSF) members in therapy of autoimmune and inflammatory diseases, a monovalent, pharmacokinetically optimized Anticalin protein format that avoids receptor clustering and therefore potential activation is favored. We investigated the suitability of an affinity-improved streptococcal Albumin-Binding Domain (ABD) and the engineered Fab-selective Immunoglobulin-Binding Domain (IgBD) SpGC3Fab for plasma Half-Life Extension (HLE) of an OX40-specific Anticalin and bispecific Duocalin proteins, neutralizing OX40 and a second co-immunostimulatory TNFRSF member. The higher affinity of ABD fusion proteins to human serum albumin (HSA) and Mouse Serum Albumin (MSA), with a 4 to 5-order of magnitude lower K_D compared with the binding affinity of IgBD fusions to human/mouse IgG, translated into longer terminal plasma half-lives (t_1/2). Hence, the anti-OX40 Anticalin-ABD protein reached t_1/2 values of ∼40 h in wild-type mice and 110 h in hSA/hFcRn double humanized mice, in contrast to ∼7 h observed for anti-OX40 Anticalin-IgBD in wild-type mice. The pharmacokinetics of an anti-OX40 Anticalin-Fc fusion protein was the longest in both models (t_1/2 of 130 h and 146 h, respectively). Protein formats composed of two ABDs or IgBDs instead of one single HLE domain clearly showed longer presence in the circulation. Importantly, Anticalin-ABD and -IgBD fusions showed OX40 receptor binding and functional competition with OX40L-induced cellular reactivity in the presence of albumin or IgG, respectively. Our results suggest that fusion to ABD or IgBD can be a versatile platform to tune the plasma half-life of Anticalin proteins in response to therapeutic needs.

MK-6, a novel not-α IL-2, elicits a potent antitumor activity by improving the effector to regulatory T cell balance

IL-2 is a pleiotropic cytokine that regulates immune cell homeostasis. Its immunomodulatory function has been used clinically as an active immunotherapy agent for metastatic cancers. However, severe adverse effects, including the vascular leak syndrome and the preferential stimulation of anti-immunogenic Treg rather than effector T cells, have been obstacles. We newly designed a mutein IL-2, Mutakine-6 (MK-6), with reduced IL-2Rα-binding capability. MK-6 induced comparable cell growth potential toward IL-2Rβγ-positive T cells but was far less efficient in in vitro Treg proliferation and STAT5 activation. Unlike IL-2, in vivo administration of MK-6 produced minimal adverse effects. Using CT26 and B16F10-syngeneic tumor models, we found MK-6 was highly efficacious on tumor regression. Serum albumin conjugation to MK-6 prolonged in vivo half-life and accumulated in CT26 tumors, showing enhanced antitumor effect. Tumor-infiltrating leukocytes analysis revealed that albumin-fused MK-6 increased the ratio of effector CD8⁺ T cells to CD4⁺ Treg cells. These results demonstrated that MK-6 is an efficient immunomodulator potentially used for improved immunotherapy with decreased adverse effects and attenuated Treg stimulation.

Modelling and Control of Corticotropin Permeation from Hydrogels across a Natural Membrane in the Presence of Albumin

(1) Background: Skin is a difficult barrier to overcome, especially for molecules with masses greater than 500 Da. It has been suggested that albumin may contribute to more effective penetration of many therapeutic substances. In this study, an attempt was made to use albumin in semi-solid formulations to increase the skin penetration of another peptide—corticotropin (ACTH). (2) Methods: Hydrogels were prepared at two concentrations: 15 mg/g and 20 mg/g corticotropin, then albumin was added to them in different stoichiometric ratios. The degree of ACTH release from hydrogels, both with and without albumin addition, was investigated. For selected hydrogels the process of corticotropin permeation through a model membrane, i.e., pig skin, was examined. (3) Results: The study of corticotropin release showed that the addition of albumin, depending on its amount, may delay or increase the release process. Similarly, a study of ACTH permeation through porcine skin showed that albumin can delay or increase and accelerate ACTH permeation. (4) Conclusions: Hydrogel, applicated on the skin surface, may prove to be a beneficial and convenient solution for patients. It is an innovative way of application ACTH that bypasses the gastrointestinal tract and may result in increased availability of the peptide and its efficacy.

Design and biological evaluation of novel long-acting adalimumab Fab conjugated with the albumin binding domain

Antigen-binding fragments (Fabs) are preferred alternatives to antibodies for medical application, whereas their short half-lives limit therapeutic effectiveness. Albumin binding domain (ABD) with high affinity for albumin possesses a great potential in enhancing in vivo performance of biotherapeutics. In this study, to mitigate the poor pharmacokinetics of adalimumab Fab targeting tumor necrosis factor-α (TNFα), an ABD fusion strategy was applied innovatively using GA3, ABD035, ABD094 and ABDCon with high affinities for albumin. The prokaryotic expression, bioactivities and half-lives of those novel Fab-ABD fusions were investigated in vitro and in vivo. All Fab-ABD fusions were successfully purified, and they retained similar TNFα-binding activities with the unmodified Fab control, also presented high affinities for human/mouse serum albumin (HSA/MSA). Additionally, the simultaneous binding of the difunctional Fab-ABD fusions to TNFα and albumin was verified, and ABD fused to Fab neither interfered with Fab-TNFα binding nor impaired the association between Fc fragment of IgG receptor and transporter (FcRn) and albumin. Based on the highest binding affinity for HSA and maximal yield, Fab-ABDCon was selected for further evaluation. Fab-ABDCon showed similar thermostability with the Fab control and robust stability in human and mouse plasma. Most notably, the pharmacokinetics of Fab-ABDCon in mice was significantly improved with a 22-fold longer plasma half-life (28.2 h) compared with that of Fab control (1.31 h), which have contributed to its satisfactory therapeutic efficacy in murine TNFα-induced hepatonecrosis model. Thus, Fab-ABDCon could be a promising long-acting candidate suitable for drug development targeting TNFα-mediated inflammatory disease.

Half-life extension of efficiently produced DARPin serum albumin fusions as a function of FcRn affinity and recycling

Serum albumin shows slow clearance from circulation due to neonatal Fc receptor (FcRn)-mediated recycling and has been used for half-life extension. We report here fusions to a high-affinity DARPin, binding to Epithelial Cell Adhesion Molecule (EpCAM). We developed a novel, efficient expression system for such fusion proteins in Pichia pastoris with titers above 300 mg/L of lab-scale shake-flask culture. Since human serum albumin (HSA) does not bind to the murine FcRn, half-lives of therapeutic candidates are frequently measured in human FcRn transgenic mice, limiting useable tumor models. Additionally, serum albumins with extended half-life have been designed. We tested HSA7, motivated by its previously claimed extraordinarily long half-life in mice, which we could not confirm. Instead, we determined a half-life of only 29 h for HSA7, comparable to MSA. The fusion of HSA7 to a DARPin showed a similar half-life. To rationalize these findings, we measured binding kinetics and affinities to murine and human FcRn. Briefly, HSA7 showed affinity to murine FcRn only in the micromolar range, comparable to MSA to its cognate murine FcRn, and an affinity in the nanomolar range only to the human FcRn. This explains the comparable half-life of MSA and HSA7 in mice, while wild-type-HSA has a half-life of only 21 h, as it does not bind the murine FcRn and is not recycled. Thus, HSA-fusions with improved FcRn-affinity, such as HSA7, can be used for preclinical experiments in mice when FcRn transgenes cannot be used, as they reflect better the complex FcRn-mediated recycling and distribution mechanisms.

Nanomedicine Strategies for Anti-Inflammatory Treatment of Noninfectious Arthritis

Noninfectious arthritis (NIA) comprises a class of chronic and progressive inflammatory disorders that require early-stage management to prevent disease progression. The most common forms include osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, and gouty arthritis. Current treatments involve nonsteroidal anti-inflammatory drugs, disease-modifying antirheumatic drugs and glucocorticoids to alleviate clinical symptoms, although regular use of these can result in a high risk of chronic kidney disease and heart failure, as well as severe adverse gastrointestinal effects. Nanomedicine offers unique opportunities to address these challenges and improve therapeutic efficacy due to its ability to deliver therapeutics locally in a sustained manner, thus extending the half-life, improving bioavailability, and reducing the side effects of these agents. This review includes a comprehensive analysis of the mechanisms of various treatment options for NIA and highlights recent progress and emerging strategies in treating NIA with nanomedicine platforms, particularly related to long-term biosafety and nonspecific targeting in designing nanomedicine delivery systems.

Hypothesis of using albumin to improve drug efficacy in cancers accompanied by hypoalbuminemia

A common problem in many cancers is the resistance of some patients to common drugs or relapse. Hypoalbuminemia has been reported in some of resistant cancer patients.This article evaluates the usefulness of albumin in the treatment of drug-resistant cancers with hypoalbuminemia based on available evidences.Rapid metabolism and drug excretion from the body is one of the causes of drug resistance. Albumin is the major plasma protein to which almost all drugs are bound. There is some evidence that increasing drug binding to albumin has beneficial effects on drug efficacy in some cancers and cancer cells. On the other hand, some reports have shown that cancer cells can use albumin as the energy and amino acid source.We have hypothesized that in this particular group of cancers, adding albumin to a treatment regimen could have a beneficial effect on drug efficacy and dosage. In fact, excess albumin can prevent rapid metabolism of drug by increasing the fraction of albumin-bound drug, and can increase drug delivery to cancer cells due to the absorption of drug-albumin complex by cancer cells.

Hyaluronic acid-green tea catechin conjugates as a potential therapeutic agent for rheumatoid arthritis

Fibroblast-like synoviocytes are a key effector cell type involved in the pathogenesis of rheumatoid arthritis. The major green tea catechin, epigallocatechin-3-O-gallate (EGCG), has attracted significant interest for rheumatoid arthritis therapy because of its ability to suppress the proliferation and interleukin-6 secretion of synoviocytes. However, therapeutic efficacy of EGCG has been limited by a lack of target cell specificity. Herein we report hyaluronic acid-EGCG (HA-EGCG) conjugates as an anti-arthritic agent that is capable of targeting fibroblast-like synoviocytes via HA-CD44 interactions. These conjugates exhibited superior anti-proliferative and anti-inflammatory activities compared with EGCG under simulated physiological conditions. Near-infrared fluorescence imaging revealed preferential accumulation of the conjugates at inflamed joints in a collagen-induced arthritis rat model, and their anti-arthritic efficacy was investigated by measuring a change in the edema and histopathological scores. Our findings suggest the potential of HA-EGCG conjugates as an anti-arthritic agent for the treatment of rheumatoid arthritis.

Prediction of Half-Life Extension of Peptides via Serum Albumin Binding: Current Challenges

The development of peptide therapeutics has increased enormously in recent decades. Many of the peptide drugs and antibody fragments that lack Fc backbone have a short half-life in circulation. In general, the half-life supports the design of the dosing regimen and frequency of administration, which are key aspects in the discovery of peptide drugs intended for long duration of action. Less frequent administration such as weekly or monthly can improve compliance and adherence to therapy. Serum albumin binding is a key approach to extend the half-life of peptide drugs. Despite the evidence of half-life prolongation of a variety of peptide drugs via albumin, quantitative prediction for humans is still a key question. Challenges in the measurement of albumin binding and in understanding the clearance mechanisms can limit quantitative prediction. We integrated pharmacokinetic concepts and albumin binding across species in a quantitative model to be used as a tool for prediction of half-life. Preliminary validation on a limited dataset indicated a good correlation between predicted and observed values. Further development of more quantitative models is warranted.

Identification and Characterization of a Peptide from the Stony Coral Heliofungia actiniformis

Marine organisms produce a diverse range of toxins and bioactive peptides to support predation, competition, and defense. The peptide repertoires of stony corals (order Scleractinia) remain relatively understudied despite the presence of tentacles used for predation and defense that are likely to contain a range of bioactive compounds. Here, we show that a tentacle extract from the mushroom coral, Heliofungia actiniformis, contains numerous peptides with a range of molecular weights analogous to venom profiles from species such as cone snails. Using NMR spectroscopy and mass spectrometry we characterized a 12-residue peptide (Hact-1) with a new sequence (GCHYTPFGLICF) and well-defined β-hairpin structure stabilized by a single disulfide bond. The sequence is encoded within the genome of the coral and expressed in the polyp body tissue. The structure present is common among toxins and venom peptides, but Hact-1 does not show activity against select examples of Gram-positive and Gram-negative bacteria or a range of ion channels, common properties of such peptides. Instead, it appears to have a limited effect on human peripheral blood mononuclear cells, but the ecological function of the peptide remains unknown. The discovery of this peptide from H. actiniformis is likely to be the first of many from this and related species.

Ceria-based nanotheranostic agent for rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease that affects 1-2% of the human population worldwide, and effective therapies with targeted delivery for local immune suppression have not been described. We address this problem by developing a novel theranostic nanoparticle for RA and assessed its therapeutic and targeting effects under image-guidance. Methods: Albumin-cerium oxide nanoparticles were synthesized by the biomineralization process and further conjugated with near-infrared, indocyanine green (ICG) dye. Enzymatic-like properties and reactive oxygen species (ROS) scavenging activities, as well as the ability to reprogram macrophages, were determined on a monocyte cell line in culture. The therapeutic effect and systemic targeting potential were evaluated in collagen-induced arthritis (CIA) mouse model using optical/optoacoustic tomographic imaging. Results: Small nanotheranostics with narrow size distribution and high colloidal stability were fabricated and displayed high ROS scavenging and enzymatic-like activity, as well as advanced efficacy in a converting pro-inflammatory macrophage phenotype into anti-inflammatory phenotype. When administrated into affected animals, these nanoparticles accumulated in inflamed joints and revealed a therapeutic effect similar to the gold-standard therapy for RA, methotrexate. Conclusions: The inflammation-targeting, inherent contrast and therapeutic activity of this new albumin-cerium oxide nanoparticle may make it a relevant agent for assessing severity in RA, and other inflammatory diseases, and controlling inflammation with image-guidance. The design of these nanotheranostics will enable potential clinical translation as systemic therapy for RA.

Antioxidant Carbon Nanoparticles Inhibit Fibroblast-Like Synoviocyte Invasiveness and Reduce Disease Severity in a Rat Model of Rheumatoid Arthritis

Reactive oxygen species have been involved in the pathogenesis of rheumatoid arthritis (RA). Our goal was to determine the effects of selectively scavenging superoxide (O2•-) and hydroxyl radicals with antioxidant nanoparticles, called poly(ethylene glycol)-functionalized hydrophilic carbon clusters (PEG-HCCs), on the pathogenic functions of fibroblast-like synoviocytes (FLS) from patients with rheumatoid arthritis (RA) and on the progression of an animal model of RA. We used human FLS from patients with RA to determine PEG-HCC internalization and effects on FLS cytotoxicity, invasiveness, proliferation, and production of proteases. We used the pristane-induced arthritis (PIA) rat model of RA to assess the benefits of PEG-HCCs on reducing disease severity. PEG-HCCs were internalized by RA-FLS, reduced their intracellular O2•-, and reduced multiple measures of their pathogenicity in vitro, including proliferation and invasion. In PIA, PEG-HCCs caused a 65% reduction in disease severity, as measured by a standardized scoring system of paw inflammation and caused a significant reduction in bone and tissue damage, and circulating rheumatoid factor. PEG-HCCs did not induce lymphopenia during PIA. Our study demonstrated a role for O2•- and hydroxyl radicals in the pathogenesis of a rat model of RA and showed efficacy of PEG-HCCs in treating a rat model of RA.

Palmitic acid-modified bovine serum albumin nanoparticles target scavenger receptor-A on activated macrophages to treat rheumatoid arthritis

Palmitic acid-modified bovine serum albumin (PAB) was synthetized and found to own remarkable scavenger receptor-A (SR-A) targeting ability in vitro and in vivo, through which activated macrophages took up PAB nanoparticles (PAB NPs) 9.10 times more than bovine serum albumin nanoparticles (BSA NPs) and PAB NPs could delivery anti-inflammatory drugs celastrol (CLT) to inflamed tissues more effectively than BSA NPs. Compared with chondroitin sulfate modified BSA NPs targeting activated macrophages via CD44, PAB NPs show a more prominent targeting effect whether in vivo or in vitro. And PAB also demonstrated excellent biosafety compared to maleylated BSA, a known SR-A ligand that was lethal in our study. Furthermore, in adjuvant-induced arthritis rats, CLT-PAB NPs significantly improved disease pathology at a lower CLT dose with high safety, compared with CLT-BSA NPs. In addition, compared with the existing ligands with SR-A targeting due to strong electronegativity, the enhanced electronegativity and introduced PA are both important for the SR-A targeting effect of PAB. Therefore, PAB provides a novel direction for the treatment of rheumatoid arthritis and design of new ligands of SR-A.

Albumin-driven disassembly of lipidic nanoparticles: the specific case of the squalene-adenosine nanodrug

In the field of nanomedicine, nanostructured nanoparticles (NPs) made of self-assembling prodrugs emerged in the recent years with promising properties. In particular, squalene-based drug nanoparticles have already shown their efficiency through in vivo experiments. However, a complete pattern of their stability and interactions in the blood stream is still lacking. In this work we assess the behavior of squalene-adenosine (SQAd) nanoparticles - whose neuroprotective effect has already been demonstrated in murine models - in the presence of fetal bovine serum (FBS) and of bovine serum albumin (BSA), the main protein of blood plasma. Extensive physicochemical characterizations were performed using Small Angle Neutron Scattering (SANS), cryogenic transmission electron microscopy (Cryo-TEM), circular dichroism (CD), steady-state fluorescence spectroscopy (SSFS) and isothermal titration calorimetry (ITC) as well as in silico by means of ensemble docking simulations with human serum albumin (HSA). Significant changes in the colloidal stability of the nanoparticles in the presence of serum albumin were observed. SANS, CD and SSFS analyses demonstrated an interaction between SQAd and BSA, with a partial disassembly of the nanoparticles in the presence of BSA and the formation of a complex between SQAd and BSA. The interaction free energy of SQAd nanoparticles with BSA derived from ITC experiments, is about -8 kcal mol^-1 which is further supported in silico by ensemble docking simulations. Overall, our results show that serum albumin partially disassembles SQAd nanoparticles by extracting individual SQAd monomers from them. As a consequence, the SQAd nanoparticles would act as a circulating reservoir in the blood stream. The approach developed in this study could be extended to other soft organic nanoparticles.

Hydroxyurea-Loaded Albumin Nanoparticles: Preparation, Characterization, and In Vitro Studies

Human serum albumin nanoparticles (HSA-NPs) have been widely used as drug delivery systems. In most cases, HSA-NPs are formed by the method of desolvation in the presence of glutaraldehyde as a crosslinking agent. In the present study, we showed the possibility of crosslinking human serum albumin (HSA) molecules with natural agents, urea, and cysteine at the nanoparticle level under mild conditions (at room temperature of 20-25 °C). Optimal concentrations of the interacting components (HSA, urea, and cysteine) were found to produce nanoparticles with optimal physico-chemical parameters (particle size, polydispersity, zeta potential, yield, etc.) for application as drug carriers. We used hydroxyurea (HU), a simple organic compound currently used as a cancer chemotherapeutic agent. The results indicated sizes of 196 ± 5 nm and 288 ± 10 nm with a surface charge of -22 ± 3.4 mV and -17.4 ± 0.5 mV for HSA-NPs (20 mg/mL of HSA, 0.01 mg/mL of cysteine, and 10 mg/mL of urea) and HSA-HU-NPs (2 mg/mL of HU), respectively. The yield of the HSA-HU-NPs was ~93% with an encapsulation efficiency of ~77%. Thus, the particles created (immobilized with HU) were stable over time and able to prolong the effect of the drug.

An effective and safe treatment strategy for rheumatoid arthritis based on human serum albumin and Kolliphor® HS 15

Aim: We aimed to construct human serum albumin-Kolliphor® HS 15 nanoparticles (HSA-HS15 NPs) to overcome the limitations in targeted therapy for rheumatoid arthritis (RA) and enhance the safety of drug-loaded HSA NPs. Methodology: Celastrol (CLT)-loaded HSA-HS15 NPs were prepared and the properties were adequately investigated; the treatment effect were evaluated in RA rats; in vitro and in vivo studies were performed to explain the mechanism. Results: CLT-HSA-HS15 NPs had remarkable treatment ability and enhanced safety in the treatment of RA compared with free CLT and CLT-HSA NPs. Conclusion: HSA-HS15 NPs could be a safe and efficient therapeutic strategy for the treatment of RA, because of the inflammatory targeting ability of albumin, the added HS15 and ELVIS effect (extravasation through leaky vasculature followed by inflammatory cell-mediated sequestration) of nanoparticles.

Role of Liposome Size, Surface Charge, and PEGylation on Rheumatoid Arthritis Targeting Therapy

Rheumatoid arthritis (RA) is a chronic, systemic, progressive autoimmune disease. The vascular permeability of inflamed joints in RA makes it a natural candidate for passive targeting, similar to the enhanced permeability and retention (EPR) effect in solid tumors. Thus, various therapeutic drugs have been encapsulated in nanocarriers to achieve longer in vivo circulation times and improve RA targeting. Although liposomes are the most widely used nanocarriers for RA treatment, the effects of physical and chemical characteristics of liposomes, such as particle sizes, surface charge, polyethylene glycol (PEG) chain length, and PEG concentration, on their passive RA targeting effect have not been fully elucidated. Here, we systematically investigated the effects of physical and chemical properties of liposomes on circulation time and conducted preliminary studies on their passive targeting mechanisms. A series of liposomes with different particle sizes (70, 100, 200, and 350 nm), surface charges (positive, negative, slight positive, and slight negative), PEG chain lengths (1, 2, and 5 kDa), and concentrations (5, 10, and 20% w/w of total lipid) were prepared by lipid film dispersion and extrusion. The pharmacokinetics of liposomes with different formulas were evaluated with a fluorescence microplate reader. A collagen-induced arthritis (CIA) mouse model was utilized to mimic RA pathological conditions and to evaluate the targeting and efficacy of liposomes with different properties using a near-infrared fluorescence imaging system. Uptake of fluorescent liposomes by various synovial cells was measured by flow cytometry. The results indicated that liposomes with 100 nm diameter, a slight negative charge, and 10% incorporation of 5 kDa PEG had better in vivo circulation time and inflamed joint targeting than did other liposomes. Dexamethasone (Dex) was encapsulated into optimized liposomes as an active ingredient for RA treatment. Pharmacodynamic studies demonstrated that Dex liposomes could significantly improve the antiarthritic efficacy of Dex in a CIA mouse model of RA. This study also found that the retention mechanism of RA was mainly increased because of the uptake of liposomes by fibroblasts and macrophages in inflamed joints. This study provides a persuasive explanation for passive RA targeting by liposomes and advances our ability to treat RA with nanomedicine.

Exploring the cytotoxic activity of new phenanthroline salicylaldimine Zn(II) complexes

Zinc(II) complexes bearing N-salicylideneglycinate (Sal-Gly) and 1,10-phenanthroline (phen) or phenanthroline derivatives [NN = 5-chloro-1,10-phenanthroline, 5-amine-1,10-phenanthroline (amphen), 4,7-diphenyl-1,10-phenanthroline (Bphen) and 5,6-epoxy-5,6-dihydro-1,10-phenanthroline] are synthesized. Complexes formulated as [Zn(NN)₂(H₂O)₂]²⁺(NN = phen and amphen), are also prepared. The cytotoxicity of the compounds is evaluated towards a panel of human cancer cells: ovarian (A2780), breast (MCF7) and cervical (HeLa), as well as non-tumoral V79 fibroblasts. All compounds display higher cytotoxicity than cisplatin (IC₅₀ = 22.5 ± 5.0 μM) towards ovarian cells, showing IC₅₀values in the low micromolar range. Overall, all compounds show higher selectivity for the A2780 cells than for the non-tumoral cells and higher selectivity indexes (IC₅₀(V79)/IC₅₀(A2780) than cisplatin. [Zn(Sal-Gly)(NN)(H₂O)] complexes induce caspase-dependent apoptosis in A2780 cells, except [Zn(Sal-Gly)(Bphen)(H₂O)], one of the most cytotoxic of the series. The cellular uptake in the ovarian cells analyzed by Inductively Coupled Plasma mass spectrometry indicates different Zn distribution profiles. Transmission electronic microscopy shows mitochondria alterations and apoptotic features consistent with caspase activation; cells incubated with [Zn(Sal-Gly)(amphen)(H₂O)] present additional nuclear membrane alterations in agreement with significant association with the nucleus. The increase of reactive oxygen species and lipid peroxidation forms could be related to apoptosis induction. [Zn(NN)₂(H₂O)₂]²⁺complexes have high ability to bind DNA through intercalation/groove binding, and circular dichroism data suggests that the main type of species that interact with DNA is [Zn(NN)]²⁺. Studies varying the % of fetal bovine serum (1-15%) in cell media show that albumin binding decreases the complex activity, indicating that distinct speciation of Zn- and phen-containing species in cell media may affect the cytotoxicity.

Extracellular Purine Metabolism Is the Switchboard of Immunosuppressive Macrophages and a Novel Target to Treat Diseases With Macrophage Imbalances

If misregulated, macrophage (Mϕ)-T cell interactions can drive chronic inflammation thereby causing diseases, such as rheumatoid arthritis (RA). We report that in a proinflammatory environment, granulocyte-Mϕ (GM-CSF)- and Mϕ colony-stimulating factor (M-CSF)-dependent Mϕs have dichotomous effects on T cell activity. While GM-CSF-dependent Mϕs show a highly stimulatory activity typical for M1 Mϕs, M-CSF-dependent Mϕs, marked by folate receptor β (FRβ), adopt an immunosuppressive M2 phenotype. We find the latter to be caused by the purinergic pathway that directs release of extracellular ATP and its conversion to immunosuppressive adenosine by co-expressed CD39 and CD73. Since we observed a misbalance between immunosuppressive and immunostimulatory Mϕs in human and murine arthritic joints, we devised a new strategy for RA treatment based on targeted delivery of a novel methotrexate (MTX) formulation to the immunosuppressive FRβ⁺CD39⁺CD73⁺ Mϕs, which boosts adenosine production and curtails the dominance of proinflammatory Mϕs. In contrast to untargeted MTX, this approach leads to potent alleviation of inflammation in the murine arthritis model. In conclusion, we define the Mϕ extracellular purine metabolism as a novel checkpoint in Mϕ cell fate decision-making and an attractive target to control pathological Mϕs in immune-mediated diseases.