Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 17 de 17
Filter
1.
Nat Biomed Eng ; 8(3): 278-290, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38378821

ABSTRACT

In vitro systems that accurately model in vivo conditions in the gastrointestinal tract may aid the development of oral drugs with greater bioavailability. Here we show that the interaction profiles between drugs and intestinal drug transporters can be obtained by modulating transporter expression in intact porcine tissue explants via the ultrasound-mediated delivery of small interfering RNAs and that the interaction profiles can be classified via a random forest model trained on the drug-transporter relationships. For 24 drugs with well-characterized drug-transporter interactions, the model achieved 100% concordance. For 28 clinical drugs and 22 investigational drugs, the model identified 58 unknown drug-transporter interactions, 7 of which (out of 8 tested) corresponded to drug-pharmacokinetic measurements in mice. We also validated the model's predictions for interactions between doxycycline and four drugs (warfarin, tacrolimus, digoxin and levetiracetam) through an ex vivo perfusion assay and the analysis of pharmacologic data from patients. Screening drugs for their interactions with the intestinal transportome via tissue explants and machine learning may help to expedite drug development and the evaluation of drug safety.


Subject(s)
Intestines , Machine Learning , Humans , Animals , Mice , Swine , Pharmaceutical Preparations/metabolism , Drug Interactions , Biological Availability
2.
Article in English | MEDLINE | ID: mdl-38253063

ABSTRACT

DISCLAIMER: In an effort to expedite the publication of articles, AJHP is posting manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time. PURPOSE: To describe our experiences implementing and iterating CYP2C19 genotype-guided clopidogrel pharmacogenetic clinical decision support (CDS) tools over time in the setting of a large health system-wide, preemptive pharmacogenomics program. SUMMARY: Clopidogrel-treated patients who are genetically predicted cytochrome P450 isozyme 2C19 intermediate or poor metabolizers have an increased risk of atherothrombotic events, some of which can be life-threatening. The Clinical Pharmacogenetics Implementation Consortium provides guidance for the use of clopidogrel based on CYP2C19 genotype in patients with cardiovascular and cerebrovascular diseases. Our multidisciplinary team implemented an automated, interruptive alert that fires when clopidogrel is ordered or refilled for biobank participants with structured CYP2C19 intermediate or poor metabolizer genomic indicators in the electronic health record. The implementation began with a narrow cardiovascular indication and setting and was then scaled in 4 primary dimensions: (1) clinical indication; (2) availability across health-system locations; (3) care venue (e.g., inpatient vs outpatient); and (4) provider groups (eg, cardiology and neurology). We iterated our approach over time based on evolving clinical evidence and proactive strategies to optimize CDS maintenance and sustainability. A key facilitator of expansion was socialization of the broader pharmacogenomics initiative among our academic medical center community, accompanied by clinician acceptance of pharmacogenetic alerts in practice. CONCLUSION: A multidisciplinary collaboration is recommended to facilitate the use of CYP2C19 genotype-guided antiplatelet therapy in patients with cardiovascular and cerebrovascular diseases. Evolving clopidogrel pharmacogenetic evidence necessitates thoughtful iteration of implementation efforts and strategies to optimize long-term maintenance and sustainability.

3.
Adv Healthc Mater ; 12(27): e2301033, 2023 10.
Article in English | MEDLINE | ID: mdl-37314859

ABSTRACT

Patient adherence to chronic therapies can be suboptimal, leading to poor therapeutic outcomes. Dosage forms that enable reduction in dosing frequency stand to improve patient adherence. Variation in gastrointestinal transit time, inter-individual differences in gastrointestinal physiology and differences in physicochemical properties of drugs represent challenges to the development of such systems. To this end, a small intestine-targeted drug delivery system is developed, where prolonged gastrointestinal retention and sustained release are achieved through tissue adhesion of drug pills mediated by an essential intestinal enzyme catalase. Here proof-of-concept pharmacokinetics is demonstrated in the swine model for two drugs, hydrophilic amoxicillin and hydrophobic levodopa. It is anticipated that this system can be applicable for many drugs with a diverse of physicochemical characteristics.


Subject(s)
Adhesives , Drug Delivery Systems , Humans , Animals , Swine , Pharmaceutical Preparations , Gastrointestinal Tract , Intestine, Small
4.
Biomaterials ; 288: 121703, 2022 09.
Article in English | MEDLINE | ID: mdl-36030104

ABSTRACT

Intravesical instillation is an efficient drug delivery route for the local treatment of various urological conditions. Nevertheless, intravesical instillation is associated with several challenges, including pain, urological infection, and frequent clinic visits for catheterization; these difficulties support the need for a simple and easy intravesical drug delivery platform. Here, we propose a novel biodegradable intravesical device capable of long-term, local drug delivery without a retrieval procedure. The intravesical device is composed of drug encapsulating biodegradable polycaprolactone (PCL) microcapsules and connected by a bioabsorbable Polydioxanone (PDS) suture with NdFeB magnets in the end. The device is easily inserted into the bladder and forms a 'ring' shape optimized for maximal mechanical stability as informed by finite element analysis. In this study, inserted devices were retained in a swine model for 4 weeks. Using this device, we evaluated the system's capacity for delivery of lidocaine and resiquimod and demonstrated prolonged drug release. Moreover, a cost-effectiveness analysis supports device implementation compared to the standard of care. Our data support that this device can be a versatile drug delivery platform for urologic medications.


Subject(s)
Drug Delivery Systems , Urinary Bladder , Administration, Intravesical , Animals , Drug Delivery Systems/methods , Drug Liberation , Swine , Urinary Bladder/metabolism
5.
Appl Clin Inform ; 13(4): 874-879, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35913087

ABSTRACT

BACKGROUND: Venipunctures and the testing they facilitate are clinically necessary, particularly for hospitalized patients. However, excess venipunctures lead to patient harm, decreased patient satisfaction, and waste. OBJECTIVES: We sought to identify contributors to excess venipunctures at our institution, focusing on electronic health record (EHR)-related factors. We then implemented and evaluated the impact of an intervention targeting one of the contributing factors. METHODS: We employed the quality improvement (QI) methodology to find sources of excess venipunctures, specifically targeting add-on failures. Once an error was identified, we deployed an EHR-based intervention which was evaluated with retrospective pre- and postintervention analysis. RESULTS: We identified an error in how the EHR evaluated the ability of laboratories across a health system to perform add-on tests to existing blood specimens. A review of 195,263 add-on orders placed prior to the intervention showed that 165,118 were successful and 30,145 failed, a failure rate of 15.4% (95% confidence interval [CI]: 15.1-15.6). We implemented an EHR-based modification that changed the criteria for add-on testing from a health-system-wide query of laboratory capabilities to one that incorporated only the capabilities of laboratories with feasible access to existing patient samples. In the 6 months following the intervention, a review of 87,333 add-on orders showed that 77,310 were successful, and 10,023 add-on orders failed resulting in a postintervention failure rate of 11.4% (95% CI: 11.1, 11.8) (p < 0.001). CONCLUSION: EHR features such as the ability to identify possible add-on tests are designed to reduce venipunctures but may produce unforeseen negative effects on downstream processes, particularly as hospitals merge into health systems using a single EHR. This case report describes the successful identification and correction of one cause of add-on laboratory failures. QI methodology can yield important insights that reveal simple interventions for improvement.


Subject(s)
Electronic Health Records , Laboratories , Humans , Patient Satisfaction , Quality Improvement , Retrospective Studies
6.
Sci Adv ; 8(21): eabm8478, 2022 05 27.
Article in English | MEDLINE | ID: mdl-35622910

ABSTRACT

Administering medicines to 0- to 5-year-old children in a resource-limited environment requires dosage forms that circumvent swallowing solids, avoid on-field reconstitution, and are thermostable, cheap, versatile, and taste masking. We present a strategy that stands to solve this multifaceted problem. As many drugs lack adequate water solubility, our formulations used oils, whose textures could be modified with gelling agents to form "oleogels." In a clinical study, we showed that the oleogels can be formulated to be as fluid as thickened beverages and as stiff as yogurt puddings. In swine, oleogels could deliver four drugs ranging three orders of magnitude in their water solubilities and two orders of magnitude in their partition coefficients. Oleogels could be stabilized at 40°C for prolonged durations and used without redispersion. Last, we developed a macrofluidic system enabling fixed and metered dosing. We anticipate that this platform could be adopted for pediatric dosing, palliative care, and gastrointestinal disease applications.


Subject(s)
Food , Oils , Animals , Child , Child, Preschool , Drug Delivery Systems , Gels , Humans , Swine , Water
7.
Sci Adv ; 7(48): eabj4624, 2021 Nov 26.
Article in English | MEDLINE | ID: mdl-34826238

ABSTRACT

Diurnal variation in enzymes, hormones, and other biological mediators has long been recognized in mammalian physiology. Developments in pharmacobiology over the past few decades have shown that timing drug delivery can enhance drug efficacy. Here, we report the development of a battery-free, refillable, subcutaneous, and trocar-compatible implantable system that facilitates chronotherapy by enabling tight control over the timing of drug administration in response to external mechanical actuation. The external wearable system is coupled to a mobile app to facilitate control over dosing time. Using this system, we show the efficacy of bromocriptine on glycemic control in a diabetic rat model. We also demonstrate that antihypertensives can be delivered through this device, which could have clinical applications given the recognized diurnal variation of hypertension-related complications. We anticipate that implants capable of chronotherapy will have a substantial impact on our capacity to enhance treatment effectiveness for a broad range of chronic conditions.

8.
J Med Toxicol ; 17(4): 397-410, 2021 10.
Article in English | MEDLINE | ID: mdl-34402038

ABSTRACT

During the current global COVID-19 pandemic and opioid epidemic, wastewater-based epidemiology (WBE) has emerged as a powerful tool for monitoring public health trends by analysis of biomarkers including drugs, chemicals, and pathogens. Wastewater surveillance downstream at wastewater treatment plants provides large-scale population and regional-scale aggregation while upstream surveillance monitors locations at the neighborhood level with more precise geographic analysis. WBE can provide insights into dynamic drug consumption trends as well as environmental and toxicological contaminants. Applications of WBE include monitoring policy changes with cannabinoid legalization, tracking emerging illicit drugs, and early warning systems for potent fentanyl analogues along with the resurging wave of stimulants (e.g., methamphetamine, cocaine). Beyond drug consumption, WBE can also be used to monitor pharmaceuticals and their metabolites, including antidepressants and antipsychotics. In this manuscript, we describe the basic tenets and techniques of WBE, review its current application among drugs of abuse, and propose methods to scale and develop both monitoring and early warning systems with respect to measurement of illicit drugs and pharmaceuticals. We propose new frontiers in toxicological research with wastewater surveillance including assessment of medication assisted treatment of opioid use disorder (e.g., buprenorphine, methadone) in the context of other social burdens like COVID-19 disease.


Subject(s)
Biomarkers/analysis , Illicit Drugs/analysis , Pharmaceutical Preparations/analysis , Substance Abuse Detection/methods , Wastewater-Based Epidemiological Monitoring , Wastewater/chemistry , Water Pollutants, Chemical/analysis , COVID-19/epidemiology , Humans , Pandemics , SARS-CoV-2 , Substance-Related Disorders/epidemiology
9.
Nat Mater ; 20(8): 1085-1092, 2021 08.
Article in English | MEDLINE | ID: mdl-34127823

ABSTRACT

Implantable drug depots have the capacity to locally meet therapeutic requirements by maximizing local drug efficacy and minimizing potential systemic side effects. Tubular organs including the gastrointestinal tract, respiratory tract and vasculature all manifest with endoluminal disease. The anatomic distribution of localized drug delivery for these organs using existing therapeutic modalities is limited. Application of local depots in a circumferential and extended longitudinal fashion could transform our capacity to offer effective treatment across a range of conditions. Here we report the development and application of a kirigami-based stent platform to achieve this. The stents comprise a stretchable snake-skin-inspired kirigami shell integrated with a fluidically driven linear soft actuator. They have the capacity to deposit drug depots circumferentially and longitudinally in the tubular mucosa of the gastrointestinal tract across millimetre to multi-centimetre length scales, as well as in the vasculature and large airways. We characterize the mechanics of kirigami stents for injection, and their capacity to engage tissue in a controlled manner and deposit degradable microparticles loaded with therapeutics by evaluating these systems ex vivo and in vivo in swine. We anticipate such systems could be applied for a range of endoluminal diseases by simplifying dosing regimens while maximizing drug on-target effects through the sustained release of therapeutics and minimizing systemic side effects.


Subject(s)
Drug Delivery Systems/instrumentation , Stents , Animals , Swine
10.
Nat Nanotechnol ; 16(6): 725-733, 2021 06.
Article in English | MEDLINE | ID: mdl-33767382

ABSTRACT

Nanoformulations of therapeutic drugs are transforming our ability to effectively deliver and treat a myriad of conditions. Often, however, they are complex to produce and exhibit low drug loading, except for nanoparticles formed via co-assembly of drugs and small molecular dyes, which display drug-loading capacities of up to 95%. There is currently no understanding of which of the millions of small-molecule combinations can result in the formation of these nanoparticles. Here we report the integration of machine learning with high-throughput experimentation to enable the rapid and large-scale identification of such nanoformulations. We identified 100 self-assembling drug nanoparticles from 2.1 million pairings, each including one of 788 candidate drugs and one of 2,686 approved excipients. We further characterized two nanoparticles, sorafenib-glycyrrhizin and terbinafine-taurocholic acid both ex vivo and in vivo. We anticipate that our platform can accelerate the development of safer and more efficacious nanoformulations with high drug-loading capacities for a wide range of therapeutics.


Subject(s)
Drug Carriers/chemistry , High-Throughput Screening Assays/methods , Nanoparticles/chemistry , Sorafenib/pharmacology , Terbinafine/pharmacology , Animals , Candida albicans/drug effects , Computer Simulation , Drug Carriers/chemical synthesis , Drug Design , Drug Evaluation, Preclinical/methods , Dynamic Light Scattering , Excipients/chemistry , Female , Glycyrrhizic Acid/chemistry , Humans , Machine Learning , Mice, Inbred Strains , Skin Absorption , Sorafenib/chemistry , Sorafenib/pharmacokinetics , Taurocholic Acid/chemistry , Terbinafine/chemistry , Tissue Distribution , Xenograft Model Antitumor Assays
11.
Sci Transl Med ; 12(558)2020 08 26.
Article in English | MEDLINE | ID: mdl-32848090

ABSTRACT

Epithelial tissues line the organs of the body, providing an initial protective barrier as well as a surface for nutrient and drug absorption. Here, we identified enzymatic components present in the gastrointestinal epithelium that can serve as selective means for tissue-directed polymerization. We focused on the small intestine, given its role in drug and nutrient absorption and identified catalase as an essential enzyme with the potential to catalyze polymerization and growth of synthetic biomaterial layers. We demonstrated that the polymerization of dopamine by catalase yields strong tissue adhesion. We characterized the mechanism and specificity of the polymerization in segments of the gastrointestinal tracts of pigs and humans ex vivo. Moreover, we demonstrated proof of concept for application of these gastrointestinal synthetic epithelial linings for drug delivery, enzymatic immobilization for digestive supplementation, and nutritional modulation through transient barrier formation in pigs. This catalase-based approach to in situ biomaterial generation may have broad indications for gastrointestinal applications.


Subject(s)
Gastrointestinal Tract , Intestine, Small , Animals , Epithelium , Swine
12.
Proc Natl Acad Sci U S A ; 117(22): 11987-11994, 2020 06 02.
Article in English | MEDLINE | ID: mdl-32424082

ABSTRACT

Chronic hepatitis C virus (HCV) infection is a leading cause of cirrhosis worldwide and kills more Americans than 59 other infections, including HIV and tuberculosis, combined. While direct-acting antiviral (DAA) treatments are effective, limited uptake of therapy, particularly in high-risk groups, remains a substantial barrier to eliminating HCV. We developed a long-acting DAA system (LA-DAAS) capable of prolonged dosing and explored its cost-effectiveness. We designed a retrievable coil-shaped LA-DAAS compatible with nasogastric tube administration and the capacity to encapsulate and release gram levels of drugs while resident in the stomach. We formulated DAAs in drug-polymer pills and studied the release kinetics for 1 mo in vitro and in vivo in a swine model. The LA-DAAS was equipped with ethanol and temperature sensors linked via Bluetooth to a phone application to provide patient engagement. We then performed a cost-effectiveness analysis comparing LA-DAAS to DAA alone in various patient groups, including people who inject drugs. Tunable release kinetics of DAAs was enabled for 1 mo with drug-polymer pills in vitro, and the LA-DAAS safely and successfully provided at least month-long release of sofosbuvir in vivo. Temperature and alcohol sensors could interface with external sources for at least 1 mo. The LA-DAAS was cost-effective compared to DAA therapy alone in all groups considered (base case incremental cost-effectiveness ratio $39,800). We believe that the LA-DAA system can provide a cost-effective and patient-centric method for HCV treatment, including in high-risk populations who are currently undertreated.


Subject(s)
Antiviral Agents/administration & dosage , Drug Delivery Systems , Hepatitis C, Chronic/drug therapy , Animals , Antiviral Agents/pharmacokinetics , Benzimidazoles/administration & dosage , Benzimidazoles/pharmacokinetics , Carbamates , Cost-Benefit Analysis , Disease Models, Animal , Drug Carriers/pharmacokinetics , Drug Delivery Systems/economics , Drug Delivery Systems/instrumentation , Drug Delivery Systems/methods , Fluorenes/administration & dosage , Fluorenes/pharmacokinetics , Hepacivirus/drug effects , Imidazoles/administration & dosage , Imidazoles/pharmacokinetics , Liver Cirrhosis/drug therapy , Models, Animal , Pyrrolidines , Ribavirin/administration & dosage , Ribavirin/pharmacokinetics , Sofosbuvir/administration & dosage , Sofosbuvir/pharmacokinetics , Swine , Valine/analogs & derivatives
13.
Cell Rep ; 30(11): 3710-3716.e4, 2020 03 17.
Article in English | MEDLINE | ID: mdl-32187543

ABSTRACT

Inactive ingredients and generally recognized as safe compounds are regarded by the US Food and Drug Administration (FDA) as benign for human consumption within specified dose ranges, but a growing body of research has revealed that many inactive ingredients might have unknown biological effects at these concentrations and might alter treatment outcomes. To speed up such discoveries, we apply state-of-the-art machine learning to delineate currently unknown biological effects of inactive ingredients-focusing on P-glycoprotein (P-gp) and uridine diphosphate-glucuronosyltransferase-2B7 (UGT2B7), two proteins that impact the pharmacokinetics of approximately 20% of FDA-approved drugs. Our platform identifies vitamin A palmitate and abietic acid as inhibitors of P-gp and UGT2B7, respectively; in silico, in vitro, ex vivo, and in vivo validations support these interactions. Our predictive framework can elucidate biological effects of commonly consumed chemical matter with implications on food- and excipient-drug interactions and functional drug formulation development.


Subject(s)
Drug Interactions , Excipients/chemistry , Food , Machine Learning , ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism , Abietanes/chemistry , Abietanes/pharmacology , Animals , Biological Assay , Diterpenes/pharmacology , Female , Glucuronosyltransferase/antagonists & inhibitors , Glucuronosyltransferase/metabolism , Hep G2 Cells , Humans , Mice, Inbred BALB C , Pharmaceutical Preparations/metabolism , Retinyl Esters/pharmacology , Swine , United States , United States Food and Drug Administration
14.
Clin Transl Gastroenterol ; 11(12): e00229, 2020 12.
Article in English | MEDLINE | ID: mdl-33512801

ABSTRACT

INTRODUCTION: Bile acids, such as chenodeoxycholic acid, play an important role in digestion but are also involved in intestinal motility, fluid homeostasis, and humoral activity. Colonic delivery of sodium chenodeoxycholate (CDC) has demonstrated clinical efficacy in treating irritable bowel syndrome with constipation but was associated with a high frequency of abdominal pain. We hypothesized that these adverse effects were triggered by local super-physiological CDC levels caused by an unfavorable pharmacokinetic profile of the delayed release formulation. METHODS: We developed novel release matrix systems based on hydroxypropyl methylcellulose (HPMC) for sustained release of CDC. These included standard HPMC formulations as well as bi-layered formulations to account for potential delivery failures due to low colonic fluid in constipated patients. We evaluated CDC release profiles in silico (pharmacokinetic modeling), in vitro and in vivo in swine (pharmacokinetics, rectal manometry). RESULTS: For the delayed release formulation in vitro release studies demonstrated pH triggered dose dumping which was associated with giant colonic contractions in vivo. Release from the bi-layered HPMC systems provided controlled release of CDC while minimizing the frequency of giant contractions and providing enhanced exposure as compared to standard HPMC formulations in vivo. DISCUSSION: Bi-phasic CDC release could help treat constipation while mitigating abdominal pain observed in previous clinical trials. Further studies are necessary to demonstrate the therapeutic potential of these systems in humans.


Subject(s)
Chenodeoxycholic Acid/administration & dosage , Drug Carriers/chemistry , Hypromellose Derivatives/chemistry , Animals , Chenodeoxycholic Acid/pharmacokinetics , Colon/chemistry , Colon/metabolism , Computer Simulation , Constipation/drug therapy , Constipation/etiology , Delayed-Action Preparations/administration & dosage , Delayed-Action Preparations/pharmacokinetics , Drug Liberation , Female , Humans , Hydrogen-Ion Concentration , Intestinal Mucosa/chemistry , Intestinal Mucosa/metabolism , Irritable Bowel Syndrome/complications , Irritable Bowel Syndrome/drug therapy , Models, Animal , Models, Biological , Peristalsis/drug effects , Swine
15.
Sci Transl Med ; 11(488)2019 04 17.
Article in English | MEDLINE | ID: mdl-30996082

ABSTRACT

We hypothesized that ingested warm fluids could act as triggers for biomedical devices. We investigated heat dissipation throughout the upper gastrointestinal (GI) tract by administering warm (55°C) water to pigs and identified two zones in which thermal actuation could be applied: esophageal (actuation through warm water ingestion) and extra-esophageal (protected from ingestion of warm liquids and actuatable by endoscopically administered warm fluids). Inspired by a blooming flower, we developed a capsule-sized esophageal system that deploys using elastomeric elements and then recovers its original shape in response to thermal triggering of shape-memory nitinol springs by ingestion of warm water. Degradable millineedles incorporated into the system could deliver model molecules to the esophagus. For the extra-esophageal compartment, we developed a highly flexible macrostructure (mechanical metamaterial) that deforms into a cylindrical shape to safely pass through the esophagus and deploys into a fenestrated spherical shape in the stomach, capable of residing safely in the gastric cavity for weeks. The macrostructure uses thermoresponsive elements that dissociate when triggered with the endoscopic application of warm (55°C) water, allowing safe passage of the components through the GI tract. Our gastric-resident platform acts as a gram-level long-lasting drug delivery dosage form, releasing small-molecule drugs for 2 weeks. We anticipate that temperature-triggered systems could usher the development of the next generation of stents, drug delivery, and sensing systems housed in the GI tract.


Subject(s)
Drug Delivery Systems/methods , Animals , Biocompatible Materials/chemistry , Esophagus/physiology , Gastrointestinal Tract/metabolism , Humans , Stomach/physiology , Temperature , Water/chemistry
16.
Sci Transl Med ; 11(483)2019 03 13.
Article in English | MEDLINE | ID: mdl-30867322

ABSTRACT

Multigram drug depot systems for extended drug release could transform our capacity to effectively treat patients across a myriad of diseases. For example, tuberculosis (TB) requires multimonth courses of daily multigram doses for treatment. To address the challenge of prolonged dosing for regimens requiring multigram drug dosing, we developed a gastric resident system delivered through the nasogastric route that was capable of safely encapsulating and releasing grams of antibiotics over a period of weeks. Initial preclinical safety and drug release were demonstrated in a swine model with a panel of TB antibiotics. We anticipate multiple applications in the field of infectious diseases, as well as for other indications where multigram depots could impart meaningful benefits to patients, helping maximize adherence to their medication.


Subject(s)
Antitubercular Agents/therapeutic use , Drug Delivery Systems , Stomach/drug effects , Tuberculosis/drug therapy , Animals , Anti-Bacterial Agents/therapeutic use , Antitubercular Agents/pharmacology , Delayed-Action Preparations , Dose-Response Relationship, Drug , Doxycycline/therapeutic use , Drug Delivery Systems/economics , Drug Liberation , Humans , Swine
17.
PLoS One ; 9(9): e106279, 2014.
Article in English | MEDLINE | ID: mdl-25247820

ABSTRACT

The need for an accurate, rapid, simple and affordable point-of-care (POC) test for Tuberculosis (TB) that can be implemented in microscopy centers and other peripheral health-care settings in the TB-endemic countries remains unmet. This manuscript describes preliminary results of a new prototype rapid lateral flow TB test based on detection of antibodies to immunodominant epitopes (peptides) derived from carefully selected, highly immunogenic M. tuberculosis cell-wall proteins. Peptide selection was initially based on recognition by antibodies in sera from TB patients but not in PPD-/PPD+/BCG-vaccinated individuals from TB-endemic settings. The peptides were conjugated to BSA; the purified peptide-BSA conjugates striped onto nitrocellulose membrane and adsorbed onto colloidal gold particles to devise the prototype test, and evaluated for reactivity with sera from 3 PPD-, 29 PPD+, 15 PPD-unknown healthy subjects, 10 patients with non-TB lung disease and 124 smear-positive TB patients. The assay parameters were adjusted to determine positive/negative status within 15 minutes via visual or instrumented assessment. There was minimal or no reactivity of sera from non-TB subjects with the striped BSA-peptides demonstrating the lack of anti-peptide antibodies in subjects with latent TB and/or BCG vaccination. Sera from most TB patients demonstrated reactivity with one or more peptides. The sensitivity of antibody detection ranged from 28-85% with the 9 BSA-peptides. Three peptides were further evaluated with sera from 400 subjects, including additional PPD-/PPD+/PPD-unknown healthy contacts, close hospital contacts and household contacts of untreated TB patients, patients with non-TB lung disease, and HIV+TB- patients. Combination of the 3 peptides provided sensitivity and specificity>90%. While the final fully optimized lateral flow POC test for TB is under development, these preliminary results demonstrate that an antibody-detection based rapid POC lateral flow test based on select combinations of immunodominant M. tb-specific epitopes may potentially replace microscopy for TB diagnosis in TB-endemic settings.


Subject(s)
Bacterial Proteins/immunology , Immunodominant Epitopes/isolation & purification , Mycobacterium tuberculosis/metabolism , Tuberculin Test/methods , Tuberculosis, Pulmonary/diagnosis , Cell Wall/immunology , Endemic Diseases/prevention & control , Humans , Immunodominant Epitopes/chemistry , Mycobacterium tuberculosis/immunology , Point-of-Care Systems , Sensitivity and Specificity , Serum Albumin, Bovine/chemistry , Tuberculin Test/economics , Tuberculosis, Pulmonary/blood , Tuberculosis, Pulmonary/immunology , Tuberculosis, Pulmonary/microbiology
SELECTION OF CITATIONS
SEARCH DETAIL
...