ANP Technologies®, Inc.

824 Interchange Boulevard  Newark, Delaware 19711

302-283-1730

info@anptinc.com

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Copyright 2018

ANP Technologies®, Inc.

Technology Overview

 
Post-Market Immunogenicity Technology Overview

As a Relevant Publications Involving ANP Immunogenicity Products:

Comparison of the NIDS® rapid assay with ELISA methods in immunogenicity testing of two biotherapeutics. Pan J, Small T, Qin D, Li S ,Wang L, Chen D, Pauley C, Verch T, Kaplanski C, Bakhtiar R, Vallejo YR, Yin R., J. Pharm. Tox. Methods63: 150-159 (2011) (ANP and Merck)

 

A double antigen bridging immunogenicity ELISA for the detection of antibodies to polyethylene glycol polymers. Liu Y, Reidler H, Pan J, Milunic D, Qin D, Chen D, Vallejo YR, and Yin R.(2011) J. Pharm. Tox. Methods, 64:238-245

 

NIDS® Rapid Assays for the Detection of Anti-Drug Antibodies to Peptide Drugs. Pan J, Small T, Qin D., Vallejo Y, Yin R.(2010) American Association of Pharmaceutical Scientists National Biotechnology Conference, San Francisco, CA May (Abstract, received the “Excellence in Ligand Binding Assays” award)

 

A Lateral Flow Immunochromatographic Method for Anti-Drug Antibody Detection in Human Serum. Jian Li, Nathan Cheadle, Allen Schantz, Gopi Shankar, poster, AAPS NBC Meeting, May 2013 (Janssen Research & Development LLC)

 

Development of a clinical assay for measuring anti-drug antibodies against a monoclonal antibody drug: Overcoming soluble target interference. Qiang Qu, Alok Rathi, Boris Gorovits, Deborah Finco, Rosalin Arends, Chun-Hua Cai, Jim McNally, poster, AAPS NBC Meeting, May 2013 (Pfizer Research and Development)

 

Introduction

 

The exceptional growth of biotherapeutics to a $125 billion industry has brought the great benefit of targeted therapy to patients. However, these large molecules cannot be employed without the possibility of toxicity or rejection due to the patient’s immune response. All the currently available innovator biotherapeutics have been shown during their development to possess acceptably low risk of immunogenicity. As these pioneering biotherapeutics lose their patent exclusivity, a large wave of potentially lower-cost biotherapeutic “generics” are in multiple development pipelines. These copies are not equivalent to the original drugs but are considered “biosimilars”, with structures that can be sufficiently different to raise uncertainties about their immunogenicity. The validity of extrapolating the safety of new proteins from predecessors with similar but not equivalent structures is limited.

 

Requirements/Recommendations on Post-Market Immunogenicity Testing by Regulatory Agencies 

Both the US FDA and the European Medicines Agency (EMA) have issued definitive guidance documents on the need to establish the risk of biotherapeutic immunogenicity. The EMA issued their guidelines several years ahead of the FDA which released its draft guidance documents in February 2012. The two agencies have very similar approaches to this safety issue.

 

The EMA documents strongly recommend post-approval assessment of immunogenicity for all biotherapeutics, while the FDA guidelines state the requirement for premarket immunogenicity studies and postmarket immunogenicity surveillance of treated patients for a minimum 1-year period, unless otherwise justified by the drug sponsor.

 

EMA Guidance on Immunogenicity

We quote the following sections (emphases added) from the EMA “Guideline on Immunogenicity Assessment of Biotechnology-Derived Therapeutic Proteins” EMEA/CHMP/BMWP/14327/2006 adopted in 2007 and effective in 2008 (emphases added):

“…unwanted immunogenicity can occur at a level, which will not be detected by such studies when conducted at a pre-approval stage, due to the restricted number of patients normally available for study. In view of this, it is often necessary to continue assessment of unwanted immunogenicity and its clinical significance post-approval, usually as part of pharmacovigilance surveillance. In some cases, post-approval clinical studies may be needed to establish the risk associated with unwanted immune response.

“The extent of data on immunogenicity that can be obtained during the clinical development programme of a biotechnology-derived product before approval depends on the event rate, driven both by the immunogenic potential of the protein and the rarity of the disease. Therefore, further systematic immunogenicity testing might become necessary after marketing authorization, and may be included in the Risk management Plan.

The extent of immunogenicity data to be collected in the post-marketing setting will depend on various factors including:

  • Disease-related factors like its prevalence, the vulnerability of the patients, availability of alternative therapies, duration of treatment, etc.

  • Pre-authorization immunogenicity findings including impact on efficacy and safety

  • Experience on immunogenicity with similar proteins or related members from that class of proteins, including proteins manufactured with similar production processes.

  • Seriousness of the immune reaction.

However, biotechnology-derived proteins should be considered individually, and therefore the possibility for extrapolation from other related proteins is limited and needs to be fully justified.

Immunogenicity can be further studied in a post-marketing setting e.g. by enhanced reporting of possibly immune-related adverse events (including loss of efficacy), or by pharmacoepidemiological studies.

 

The EMA has also released the “Guideline on immunogenicity assessment of monoclonal antibodies intended for in vivo clinical use” EMA/CHMP/BMWP/86289/2010, currently in its consultation phase. From it we quote (emphasis added):

“In many cases, the incidence of immune response is too low to be fully identified during Phase III clinical studies. Therefore systematic post-authorization monitoring may be necessary and should be adequately organized to capture clinical signs that could be related to immunogenicity. The involvement of antibodies in this should be established by conducting appropriate assays.

 

FDA Draft Guidance on Immunogenicity

The latest draft guidance on Biosimilars released by the FDA in February 2012, “Scientific Considerations in Demonstrating Biosimilarity to a Reference Product” states that, at the very least, two separate immunogenicity studies should be conducted to compare any biosimilar to its reference product:

“(1) a premarket study powered to detect major differences in immune responses between the two products and (2) a postmarket study designed to detect more subtle differences in immunogenicity.”(see lines 548-559)

 

In addition, the draft guidance goes on to state the following:

“The follow-up period should be determined based on (1) the time course for the generation of immune responses (such as the development of neutralizing antibodies, cell-mediated immune responses), and expected clinical sequelae (informed by experience with the reference product), (2) the time course of disappearance of the immune responses and clinical sequelae following cessation of therapy, and (3) the length of administration of the product. For example, the minimal follow-up period for chronically administered agents should be one year, unless a shorter duration can be justified by the sponsor.” (See lines 592-599)

 

Centralized Pre-Market Immunogenicity Tests vs. Decentralized Post-Market Testing

Pre-market immunogenicity studies are carried out in a centralized manner using well-organized collection procedures and schedules from properly defined and traceable donor cohorts under a defined and controlled study plan. Post-market immunogenicity surveillance, however, will involve patients who are globally dispersed and may be well enough to lead normal lives. Immunogenicity test methods have to be made available wherever patients live.

 

Post-market immunogenicity testing resembles in great degree personalized medicine tests that need to be available in point of care (POC) settings. Whether performed by a physician or the patient, post-market immunogenicity testing will be a low-volume, highly decentralized activity. Personalized immunogenicity testing should be performed before and during biotherapeutic treatment. A pre-treatment evaluation will serve to uncover pre-existing antibodies and enable a physician to evaluate the risk and rationale for using the specific biotherapeutic drug.

 

Need for Post-Market POC Immunogenicity Rapid/Monitoring Tests

Rapid immunogenicity tests that can be performed by a primary care physician or ideally, by the patient himself, are the best solutions. Currently there are no POC assays for post-market immunogenicity monitoring. Since these tests are not broadly applicable and are specific to each biotherapeutic with a limited user community, they are not attractive opportunities for large diagnostic businesses which depend on high volume and high-throughput tests.

 

Alliances between biopharmaceutical companies and specialized diagnostic companies are the keys to delivering these necessary post-market surveillance tools. A drug company can make its biotherapeutic available to the diagnostic entity to develop the rapid POC immunogenicity test. Although target drugs will originate from multiple companies, it is important to develop these tests on a common platform in order to simplify POC testing for physician’s offices and remote clinics.

 

ANP Technologies®, Inc. has successfully developed rapid immunogenicity tests for both innovator and biosimilar biotherapeutics for established biopharmaceutical companies using its handheld reader-based NIDS® technology. Its PEG Rapid Immunogenicity test kit can be used universally in a POC setting to detect PEG-specific anti-drug antibodies in patients undergoing treatment with any of the large number of PEGylated drugs. ANP’s successful collaboration with biopharmaceutical companies has created an opportunity to develop its NIDS® handheld technology as the common platform for future POC immunogenicity tests for post-market surveillance and patient monitoring.

 

ANP Reagents: an Open Platform for Immunogenicity Testing

ANP has developed many IM ELISAs and rapid IM assays for its clients. It now offers the biopharmaceutical scientist all its tools so that IM assays in either format are now within easy reach. The IM assay developer can now acquire all the reagents to develop IM assays from ANP. ANP’s quality reagents are easy to use and are based on ANP’s nanomanipulation technology, the Nano-Intelligent Detection System (NIDS®). ANP offers the following products to assist you in developing immunogenicity assays for your specific biotherapeutic drug:

 

NIDS® HyperBind Streptavidin/Neutravidin coated plates: The NIDS® technology, specifically designed for large molecule testing, significantly improves the binding efficiency of biotinylated proteins and increases the sensitivity of IM ELISAs.

 

NIDS® DIY Biotin Labeling Kits: Complete Do-It-Yourself kits for the biotinylation of proteins using linkers optimized for use with our HyperBind plates. Included are conjugation and purification reagents, as well as rapid QC strips to confirm that your protein has been successfully biotinylated.
 

NIDS® DIY Digoxigenin Labeling Kits: Complete Do-It-Yourself kits for the digoxigenin-labeling and purification of proteins using linkers optimized for use with our HyperBind plates. Included are conjugation and purification reagents, as well as rapid QC strips to confirm that your protein has been successfully labeled with digoxigenin.

 

NIDS® DIY Immunogenicity ELISA kit: A complete Do-It-Yourself kit containing 10 HyperBind plates, biotinylation and digylation kits and all the reagents to optimize an IM ELISA for your drug.

 

NIDS® DIY Rapid Immunogenicity Assay Development Kit: Under development is a complete Do-It-Yourself kit to develop a rapid IM assay using ANP’s NIDS® reagents. Included is a dedicated handheld reader for use with assay strips.

 

PEG IM ELISA kit: This is a pioneering universal method for the detection of PEG-specific ADAs to any PEGylated drug. It detects ADAs to PEG molecules of various structures, lengths, and linking groups.

 

PEG Rapid IM Assay: Under development is a rapid assay for the detection of PEG-specific ADAs to any PEGylated drug. It detects ADAs to PEG molecules of various structures, lengths, and linking groups.

 

NIDS® NPX4000 Interfering Protein Extraction kit: A simple and easy-to-use kit capable of irreversible removal of interfering endogenous proteins such as drug target compounds, which can cause erroneous results in immunogenicity and PK assays, using ANP’s proprietary nanoparticles.

 

ANP Assay Development Services: ANP offers its bioconjugation and immunogenicity assay development expertise free of charge to any user of our DIY kits. ANP can also develop immunogenicity methods in ELISA or rapid assay format for clients who prefer to do so.

 

 

Quick Search:​

  • NIDS® PEG Immunogenicity

  • NIDS® HyperBind Streptavidin/Neutravidin ELISA Plates

  • Antibodies

  • Biotinylated Antibodies

  • Biotinylation and Digoxigenin Labeling Kits

  • Protein Extraction Kit

  • Immunoassay Diluent

 
Immunogenicity Testing and Immunogenicity Assays

As a Relevant Publications Involving ANP Immunogenicity Products:

Comparison of the NIDS® rapid assay with ELISA methods in immunogenicity testing of two biotherapeutics. Pan J, Small T, Qin D, Li S ,Wang L, Chen D, Pauley C, Verch T, Kaplanski C, Bakhtiar R, Vallejo YR, Yin R., J. Pharm. Tox. Methods63: 150-159 (2011) (ANP and Merck)

 

A double antigen bridging immunogenicity ELISA for the detection of antibodies to polyethylene glycol polymers. Liu Y, Reidler H, Pan J, Milunic D, Qin D, Chen D, Vallejo YR, and Yin R.(2011) J. Pharm. Tox. Methods, 64:238-245

 

NIDS® Rapid Assays for the Detection of Anti-Drug Antibodies to Peptide Drugs. Pan J, Small T, Qin D., Vallejo Y, Yin R.(2010) American Association of Pharmaceutical Scientists National Biotechnology Conference, San Francisco, CA May (Abstract, received the “Excellence in Ligand Binding Assays” award)

 

A Lateral Flow Immunochromatographic Method for Anti-Drug Antibody Detection in Human Serum. Jian Li, Nathan Cheadle, Allen Schantz, Gopi Shankar, poster, AAPS NBC Meeting, May 2013 (Janssen Research & Development LLC)

 

Development of a clinical assay for measuring anti-drug antibodies against a monoclonal antibody drug: Overcoming soluble target interference. Qiang Qu, Alok Rathi, Boris Gorovits, Deborah Finco, Rosalin Arends, Chun-Hua Cai, Jim McNally, poster, AAPS NBC Meeting, May 2013 (Pfizer Research and Development)

 

Introduction

 

Immunogenicity (IM) testing is a necessary step in the development of any biotherapeutic drug. Innovative strategies have been used to reduce the potential immunogenicity of these large molecules. PEGylation, humanized structures, and chimeric constructs have proven to varying degrees to be effective measures to ensure that a biologic drug’s efficacy and safety are not compromised by the patient’s own immune response. However, none of these inventive designs ensure that biotherapeutics will be immune from the problem of patient rejection and toxicity.

 

With the arrival of biosimilars or the equivalent of biotherapeutic generic drugs, immunogenicity testing will likely still be required even when the original name brand drug has acceptable immunogenicity.

 

This is because unlike small molecule generic drugs which have exactly the same chemical structures as their predecessors, biosimilars, produced by different processes, or at different scale, even when using the same process, may have minor variations in chemical structures and impurity levels, thus eliciting different immunogenic reactions when administered in humans.

 

The latest draft guidance on Biosimilars released by the FDA in February 2012, “Scientific Considerations in Demonstrating Biosimilarity to a Reference Product” states that, at the very least, two separate immunogenicity studies should be conducted to compare any biosimilar to its reference product:

“(1) a premarket study powered to detect major differences in immune responses between the two products and (2) a postmarket study designed to detect more subtle differences in immunogenicity.”(see lines 548-559)

 

In addition, the draft guidance goes on to state the following:

“The follow-up period should be determined based on (1) the time course for the generation of immune responses (such as the development of neutralizing antibodies, cell-mediated immune responses), and expected clinical sequelae (informed by experience with the reference product), (2) the time course of disappearance of the immune responses and clinical sequelae following cessation of therapy, and (3) the length of administration of the product. For example, the minimal follow-up period for chronically administered agents should be one year, unless a shorter duration can be justified by the sponsor.” (See lines 592-599)

 

Choice of Methods for Immunogenicity Testing

The biopharmaceutical scientist can choose from several technologies to perform immunogenicity testing. A double antigen bridging assay has been preferred since such a method, once optimized, can be applied to immunogenicity testing in any host species. Thus, the same IM assay can be used for early animal studies and clinical studies in humans. Each technology platform has its advantages and disadvantagese:

 

ELISA is a well proven, low cost, open technology platform for detecting high affinity anti-drug antibodies (ADAs). It has superior drug tolerance, but may miss low affinity ADAs due to the requirement of high sample dilution and multiple wash steps that may disrupt weakly bound ADA-drug complexes. ELISA can detect ADAs after acid dissociation of drug complexed antibodies.

 

ANP’s NIDS® IM ELISA assay can be used in neat serum without the need for sample dilution. In addition, it only requires one wash step, thus significantly improving the IM ELISA assay performance (related publication). PEG IM ELISA has also been successfully developed using this method (related publication).

 

Surface Plasmon Resonance (SPR, Biacore) IM assay, has been shown to be efficient in the detection of low affinity ADAs, but overall is not as sensitive as ELISA due to the label free assay configuration and the requirement for sample dilution. It shows higher drug tolerance for low affinity ADAs, but cannot be used with acid dissociation of circulating complexes. The method requires investment in costly dedicated instrumentation. Similar problems also exist in the Bio-Layer Interferometry (BLI) Dip and Read based IM assays.

 

Electrochemiluminescence (ECL) IM assay is very similar to ELISA in performance with the claims of improved sensitivity from the use of an electrochemiluminescent label. However, similar shortcomings with the detection of low affinity ADAs due to the need for sample dilution and a final wash step still exist in addition to a significantly higher cost in equipment and reagents, when compared to regular ELISA. The method requires investment in costly dedicated instrumentation.

 

Rapid Immunogenicity assay using immunochromatographic test strips is a newly developed IM assay method that requires no sample dilution and wash steps, thus capable of detecting both high and low affinity ADAs. It is very tolerant of acid dissociated samples. ANP’s NIDS® rapid IM assay can be utilized for not only patient sample testing during clinical trials, but more importantly the near-patient monitoring of immunogenic reactions, particularly after the biologic drug/biosimilar is approved (related publication). ANP offers various rapid IM assay products and services using both a handheld reader and a high throughput screening (HTS) reader.

 

Challenges in the Detection of ADAs: Immune Complexes and Endogenous Interfering Proteins

 

Immune Complexes

ADAs in an immune patient may already be bound to the biotherapeutic drug in circulating immune complexes, especially in the presence of excess drug. Unless dissociated from these complexes, the ADA will not be detectable in any IM assay of any format. The typical approach to this challenge is to perform an acid dissociation pre-treatment of the sample to liberate ADA from the immune complexes, then after neutralization, immediately run the IM assay. The IM assay has to be run immediately after neutralization to prevent the immune complexes from reforming.

 

Endogenous Protein and Target Interference

Endogenous protein interferences can cause erroneous results in immunogenicity tests in whatever format. For monoclonal antibodies and similar biotherapeutics that function by binding and blocking disease-associated active proteins, the drug’s target molecule can by itself create a bridging or sandwich complex with the drug conjugate reagents in the IM assay. This leads to a false positive result in IM assays in the absence of ADA.

 

Acid dissociation by itself will not resolve this problem. Other approaches that may work involve using a separate blocking antibody that will bind interfering target proteins prior to running an immunogenicity assay. Once blocked, the target molecules can no longer form bridging complexes with the drug conjugate reagents. However, these blocking antibodies can be dissociated from the target molecules upon acid dissociation, thus removing their corrective effect. If added immediately after the neutralization step in the acid dissociation process, the blocker will not have enough time to bind target proteins since the IM assay has to be run immediately.

 

The simplest approach is to irreversibly extract or scavenge the interfering endogenous proteins prior to running the IM assay. The NIDS® NPX4000 Interfering Protein Extraction Kit enables the irreversible removal of these interfering endogenous proteins by attaching your specific blocking antibody or binder to activated particles, pretreating the sample with these particles, then cleanly separating them with the bound interferents . More than 99% of the interfering drug target can be removed by these easy to use particles without affecting ADA levels. We have found that these particles use significantly less blocking antibody or binder than conventional methods.

 

ANP Reagents: an Open Platform for Immunogenicity Testing

ANP has developed many IM ELISAs and rapid IM assays for its clients. It now offers the biopharmaceutical scientist all its tools so that IM assays in either format are now within easy reach. The IM assay developer can now acquire all the reagents to develop IM assays from ANP. ANP’s quality reagents are easy to use and are based on ANP’s nanomanipulation technology, the Nano-Intelligent Detection System (NIDS®). ANP offers the following products to assist you in developing immunogenicity assays for your specific biotherapeutic drug:

 

NIDS® HyperBind Streptavidin/Neutravidin coated plates: The NIDS® technology, specifically designed for large molecule testing, significantly improves the binding efficiency of biotinylated proteins and increases the sensitivity of IM ELISAs.

 

NIDS® DIY Biotin Labeling Kits: Complete Do-It-Yourself kits for the biotinylation of proteins using linkers optimized for use with our HyperBind plates. Included are conjugation and purification reagents, as well as rapid QC strips to confirm that your protein has been successfully biotinylated.
 

NIDS® DIY Digoxigenin Labeling Kits: Complete Do-It-Yourself kits for the digoxigenin-labeling and purification of proteins using linkers optimized for use with our HyperBind plates. Included are conjugation and purification reagents, as well as rapid QC strips to confirm that your protein has been successfully labeled with digoxigenin.

 

NIDS® DIY Immunogenicity ELISA kit: A complete Do-It-Yourself kit containing 10 HyperBind plates, biotinylation and digylation kits and all the reagents to optimize an IM ELISA for your drug.

 

NIDS® DIY Rapid Immunogenicity Assay Development Kit: Under development is a complete Do-It-Yourself kit to develop a rapid IM assay using ANP’s NIDS® reagents. Included is a dedicated handheld reader for use with assay strips.

 

PEG IM ELISA kit: This is a pioneering universal method for the detection of PEG-specific ADAs to any PEGylated drug. It detects ADAs to PEG molecules of various structures, lengths, and linking groups.

 

PEG Rapid IM Assay: Under development is a rapid assay for the detection of PEG-specific ADAs to any PEGylated drug. It detects ADAs to PEG molecules of various structures, lengths, and linking groups.

 

NIDS® NPX4000 Interfering Protein Extraction kit: A simple and easy-to-use kit capable of irreversible removal of interfering endogenous proteins such as drug target compounds, which can cause erroneous results in immunogenicity and PK assays, using ANP’s proprietary nanoparticles.

 

ANP Assay Development Services: ANP offers its bioconjugation and immunogenicity assay development expertise free of charge to any user of our DIY kits. ANP can also develop immunogenicity methods in ELISA or rapid assay format for clients who prefer to do so.

 

 

 
NIDS® High Throughput Screening (HTS) System for Rapid Immunogenicity Assays and Antibody

ANP has developed a high throughput system for high volume screening of test samples on rapid immunogenicity assay test strips. A multistrip carrier, a tray that can hold test strips for 12 patient samples, is the basic test device in this system. This carrier has the same footprint and layout of a 96-well ELISA microplate so that it is fully compatible with available ELISA robotic systems. Sample incubation and transfer to test strips can therefore be automated, with the finished strips being read in their trays by the NIDS® HTS reader. 

 

This high throughput screening system enables the use of Rapid Immunogenicity and other assays in high volume preclinical and clinical studies.

 

In addtion, with antigen usage substantially reduced, the HTS provides a significantly faster (less than 15 min) and simpler (one-step) low-cost alternative to multi-step ELISA-based screening for the development of antibody drugs.

A Multistrip Carrier holding 12 rapid assay test strips

The ANP NIDS® High Throughput Screening reader. Two multistrip carriers are ready to be read on the two trays on the right. Results are displayed on the top screen as shown.

 
NIDS® High Sensitivity HyperBind ELISA Plates

Reference: Vallejo YR, Li J, Yin R. Enhancing assay performance using nanoscale detection. IVD Technology,Volume 16, May/June 2010

 

Please click here for a list of available HyperBind activated ELISA plates

 

High Sensitivity NIDS® HyperBind activated streptavidin or neutravidin-coated ELISA plates have proven to be the most sensitive ELISA plates for Serological Assays. These plates deliver dramatically enhanced sensitivity using significantly reduced levels of antigens for serological assays such as those for the detection of antibodies to proteins associated with HIV, HCV, the TORCH panel (toxoplasma, rubella, CMV, herpes simplex), various viral, bacterial and parasitical infectious diseases such as influenza, typhoid fever, lyme disease, allergy and a wide range of autoimmune diseases. Serological assays are also important in detecting the immunogenicity of biotherapeutic proteins. 

 

Advantages:

  • High Efficiency Coating

  • Low-cost

  • Ready to use: plates are pre-blocked with BSA

  • Sensitive: Detection of < 1 ng/mL of antibody or protein is easily attainable

  • Specific: High signal to noise ratios with low background

  • Stable: > 18 months at room temperature

 

Serologic methods have in common the use of a solid surface onto which is coated a bioreactive immunogenic protein. These biomolecules are typically complex long chain structures possessing optimal 3-dimensional conformation with specific loci for binding sites or epitopes. The conventional deposition of bioactive molecules onto solid surfaces is an inefficient and random process. For example, antibodies can easily be coated onto a plastic surface but only a subset of the deposited molecules will have the Fab binding regions available for reaction (Figure 1). This randomness limits both the binding capacity and sensitivity of assays that depend on conventional coating technology.

 

The Nano-Intelligent Detection System (NIDS®) technology has been designed to control the orientation of bioactive molecules at the nanoscale level by using a polymeric scaffold covalently conjugated to a binder such as an antibody1. Within this conjugate structure, the polymeric scaffold preferentially attaches itself to the solid surface, and extends the antigen away from the surface for most advantageous immunoreaction.The result of this innovation is a coated surface that exhibits greater binding efficiency.

Figure 1. Orientation of antibodies is random in conventional coating and optimally oriented with NIDS® nano-orientation technology

High Sensitivity NIDS® HyperBind plates deliver to users assays of greater sensitivity along with significantly reduced reagent usage, which is a critical consideration when these coating proteins are difficult to isolate and expensive to acquire.

 

High Sensitivity HyperBind plates are available in clear, black, and white formats for colorimetric, fluorometric and chemiluminescent assay formats, respectively. Our plates have been compared to many commercial plates. The nanoscale orientation achieved by conjugating Streptavidin or Neutravidin to the anchoring polymeric scaffold has led to impressive performance enhancements.

 

Comparison of Direct Binding of Biotinylated Proteins for Serological Assays

High Sensitivity HyperBind strreptavidin (SA) coatedplates exhibit greater binding efficiency of biotinylated proteins than leading commercial SA plates (Figure 2). In a representative model serological assay, 100 μL of increasing concentrations of biotinylated mouse IgG antibody are added to the wells of a High Sensitivity HyperBind, a Nunc Immobilizer™, a Pierce HBC Reacti-Bind™, and an R&D Systems EvenCoat™ plate and incubated for an hour on a platform shaker. After washing, 100 μL of rabbit anti-mouse IgG conjugated to horseradish peroxidase (HRP) are added to the wells and allowed to incubate for an hour and a half on a platform shaker. Following a wash step, the substrate/chromogen reagent consisting of hydrogen peroxide and tetramethylbenzidine(TMB) is added to the wells and color allowed to develop for 20 minutes, stopped with 2N sulfuric acid and the absorbance measured at 450 nm.

 

Figure 2. The binding efficiency of HyperBind clear plates is significantly greater than leading commercial plates.

White plates were also treated with NIDS®-activated Streptavidin for use in chemiluminescence-based assays. The binding efficiency of the HyperBind™ plates was shown to be superior to that of the Nunc Immobilizer™ white plate using the test procedure with biotinylated mouse IgG previously described and a chemiluminescent substrate reagent.

 

Figure 3. Binding efficiency of HyperBind™ black Streptavidin (SA) and Neutravidin (NA) plates is superior to that of commercial plates.

WWhite plates were also treated with NIDS®-activated Streptavidin for use in chemiluminescence-based assays. The binding efficiency of the HyperBind™ plates was shown to be superior to that of the Nunc Immobilizer™ white plate using the test procedure with biotinylated mouse IgG previously described and a chemiluminescent substrate reagent.

 

Figure 4. Binding efficiency of HyperBind white Streptavidin (SA) plates is superior to that of a commercial plate.

The conclusion derived from the above experiments is that for a given concentration of biotinylated protein added to the microwells, more is bound by the High Sensitivity NIDS® HyperBind clear, black, and white plates than the Pierce, R&D Systems, and Nunc plates. This finding translates to significantly better assay performance and major reductions in reagent use and cost when designing Serological Assays.

 

In addition, High Sensitivity NIDS® HyperBind plates can also be used for competitive assays and direct detection analytical methods which require immobilization of antigens directly on a solid surface.

 
Endogenous Protein Extraction Using NIDS® Nanoparticles

Our NIDS® nanoparticle based universal protein extraction kits exhibit the following advantages:

1. Smaller diameter, greater surface area compared to micron-size magnetic particles which are the current particles of choice. Extraction efficiency and capacity are significantly enhanced. Up to 1 µg/mL of endogenous interfering protein can be removed.

 

2. Binding agents are optimally oriented. The binding agents are attached using our NIDS® chemistry which employs proprietary linkers that orient the binding sites outwardly to capture their targets most efficiently. Other particle-coating chemistries will not work as well.

 

3. Less binding agent used. As much as 100-fold less of scavenging agents such as antibodies is required.

 

4. Easy to use procedure. Optimal loading and particle usage are easily calculated.

 

5. Flexible universal platform. Any protein or nucleic acid can be coated onto our nanoparticles. The customer can choose from a list of binding agents for 140 different endogenous proteins currently available or provide their own binding agents for attachment to the extraction nanoparticles.

 

Bioanalytical methods such as diagnostic, pharmacokinetic, pharmacodynamic, and immunogenicity assays have shown improved accuracy and sensitivity after sample pretreatment using these innovative extraction nanoparticles linked to target-specific off-the-shelf binding reagents such as antibodies. Our NIDS® nanoparticle based protein extraction kits are currently being used by leading biopharmaceutical companies in various stages of drug development.