Control of blood clotting using gold nanorods

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2013.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references.We have developed a method to externally control blood clotting using gold nanoparticles. Gold nanorods (NRs) have unique size and shape-dependent optical properties that can be used for externally controlled release of biomolecules by laser excitation. Femtosecond pulsed laser irradiation at the NR longitudinal surface plasmon resonance peak (LSPR) can excite the NRs and induce melting, and thus cause release of drug or biomolecular payload on the NR. Because the peak wavelength of the LSPR changes with NR aspect ratio, NRs with different aspect ratios can be independently excited at different wavelengths to release different payloads in a mutually exclusive fashion. This approach can be used to create a biological switch for blood clotting by releasing a single stranded (ssDNA) thrombin binding aptamer (TBA) upon laser irradiation. It is possible to control blood clotting by releasing TBA that binds and inhibits thrombin, and an antidote consisting of a complementary ssDNA sequence that binds to TBA and restores thrombin activity. Both the TBA and the antidote are loaded onto NRs with different aspect ratios. This enables us to use laser excitation at one wavelength to deliver the TBA and inhibit thrombin and consequently blood clotting. We then use a different wavelength to deliver the antidote and reverse the effect of the TBA. We use covalent attachment techniques (thiol-gold binding) for loading the ssDNA on the NRs and study the interface between the NRs and the biomolecules. We also take advantage of serum protein coronas for loading, which enable enhanced loading capacities. This localized, selective and externally controlled release of biomolecules represents an advance that could impact a number of biological applications, where the current practice is systemically administering drugs though the whole bloodstream and relying on physiological clearance to restore the system.by Helena de Puig Guixé.S.M

IL-1 Family Cytokines in Inflammatory Dermatoses : Pathogenetic Role and Potential Therapeutic Implications

The interleukin-1 (IL-1) family is involved in the correct functioning and regulation of the innate immune system, linking innate and adaptative immune responses. This complex family is composed by several cytokines, receptors, and co-receptors, all working in a balanced way to maintain homeostasis. Dysregulation of these processes results in tissue inflammation and is involved in the pathogenesis of common inflammatory dermatoses such as psoriasis, hidradenitis suppurativa, and atopic dermatitis. Therefore, therapeutic targeting of IL-1 pathways has been studied, and several monoclonal antibodies are currently being assessed in clinical trials. So far, promising results have been obtained with anti-IL-36R spesolimab and imsidolimab in pustular psoriasis, and their efficacy is being tested in other conditions

Dual inhibition of IL-17A and IL-17F in psoriatic disease

Psoriasis and psoriatic arthritis are chronic immune-mediated disorders with involvement of interleukin (IL)-17 cytokines in their pathogenesis. IL-17A has been considered to be the most biologically active, but IL-17F is also over-expressed in skin and synovial tissues of patients with these diseases. Many therapeutic advances have been made in the past years, but some needs remain unmet. Dual inhibitor and bispecific antibodies simultaneously targeting IL-17A and IL-17F could provide better disease control. Herein we review current evidence on bimekizumab and sonelokimab. The antigen-binding site of bimekizumab neutralizes both IL-17A and IL-17F; phase I, II, and III studies have demonstrated its efficacy and safety in psoriasis and psoriatic arthritis. Sonelokimab is a trivalent nanobody targeting IL-17A and IL-17F; phase I and II studies with this molecule have yielded promising results in psoriasis

Extinction Coefficient of Gold Nanostars

Gold nanostars (NStars) are highly attractive for biological applications due to their surface chemistry, facile synthesis, and optical properties. Here, we synthesize NStars in HEPES buffer at different HEPES/Au ratios, producing NStars of different sizes and shapes and therefore varying optical properties. We measure the extinction coefficient of the synthesized NStars at their maximum surface plasmon resonances (SPRs), which range from 5.7 × 10⁸ to 26.8 × 10⁸ M⁻¹ cm⁻¹. Measured values correlate with those obtained from theoretical models of the NStars using the discrete dipole approximation (DDA), which we use to simulate the extinction spectra of the nanostars. Finally, because NStars are typically used in biological applications, we conjugate DNA and antibodies to the NStars and calculate the footprint of the bound biomolecules.United States. National Institutes of Health (AI100190

Quantifying the nanomachinery of the nanoparticle-biomolecule interface

A study is presented of the nanomechanical phenomena experienced by nanoparticle-conjugated biomolecules. A thermodynamic framework is developed to describe the binding of thrombin-binding aptamer (TBA) to thrombin when the TBA is conjugated to nanorods. Binding results in nanorod aggregation (viz. directed self-assembly), which is detectable by absorption spectroscopy. The analysis introduces the energy of aggregation, separating it into TBA–thrombin recognition and surface-work contributions. Consequently, it is demonstrated that self-assembly is driven by the interplay of surface work and thrombin-TBA recognition. It is shown that the work at the surface is about −10 kJ mol−1 [mol superscript -1] and results from the accumulation of in-plane molecular forces of pN magnitude and with a lifetime of <1 s, which arises from TBA nanoscale rearrangements fuelled by thrombin-directed nanorod aggregation. The obtained surface work can map aggregation regimes as a function of different nanoparticle surface conditions. Also, the thermodynamic treatment can be used to obtain quantitative information on surface effects impacting biomolecules on nanoparticle surfaces.MIT-IQS Exchange Progra

Rapid Diagnostics for Infectious Disease using Noble Metal Nanoparticles

Rapid point-of-care (POC) diagnostic devices are needed for field-forward screening of severe acute systemic febrile illnesses such as dengue, Ebola, chikungunya, and others. Multiplexed rapid lateral flow diagnostics have the potential to distinguish among multiple pathogens, thereby facilitating diagnosis and improving patient care. We present a platform for multiplexed pathogen detection which uses gold or silver nanoparticles conjugated to antibodies to sense the presence of biomarkers for different infectious diseases. We exploit the size-dependent optical properties of Ag NPs to construct a multiplexed paperfluidic lateral flow POC sensor. AgNPs of different sizes were conjugated to antibodies that bind to specific biomarkers. Red AgNPs were conjugated to antibodies that could recognize the glycoprotein for Ebola virus, green AgNPs to those that could recognize nonstructural protein 1 for dengue virus, and orange AgNPs for non structural protein 1 for yellow fever virus. Presence of each of the biomarkers resulted in a different colored band on the test line in the lateral flow test. Thus, we were able to use NP color to distinguish among three pathogens that cause a febrile illness. Because positive test lines can be imaged by eye or a mobile phone camera, the approach is adaptable to low-resource, widely deployable settings. This design requires no external excitation source and permits multiplexed analysis in a single channel, facilitating integration and manufacturing. We will also discuss engineering the nanoparticle physical properties and surface chemistry for improving detection and also optimizing device properties, and expansion of the device to detect other diseases

O pensamento disruptivo do cuidado

Cuidado, cuidando, cuidadora. Palavras carregadas, contestadas. Ainda assim, tão comuns na vida cotidiana, é como se o cuidado fosse natural, para além de alguma expertise ou conhecimento particular. A maioria de nós precisa do cuidado, sente o cuidado, é cuidada ou encontra o cuidado em uma ou outra forma. O cuidado é onipresente, inclusive através dos efeitos da sua ausência. Como um sentimento de falta que emana dos efeitos da negligência, ele passa dentro, através, por todas as coisas. Su..

A Randomized Clinical Trial to Evaluate the Effects of Safinamide on Apathetic Non-demented Patients With Parkinson's Disease

Altres ajuts: CERCA; CIBERNED; La Marató de TV3 (2014/U/477, 20142910); Fondo Europeo de Desarrollo Regional (FEDER).Background: Apathy is highly prevalent and disabling in Parkinson's disease (PD). Pharmacological options for its management lack sufficient evidence. Objective: We studied the effects of safinamide on apathy in PD. Methods: Prospective, 24-week, two-site, randomized, double-blind, placebo-controlled, parallel-group exploratory study in non-demented PD on stable dopaminergic therapy randomized 1:1 to adjunct safinamide (50 mg/day for 2 weeks and 100 mg/day for 22 weeks) or placebo. The primary endpoint was the mean change from baseline to week 24 on the Apathy Scale (AS) total score. Secondary endpoints included changes in cognition, activities of daily living, motor scores, the impression of change, and safety and tolerability measures. Results: In total, 30 participants (active treatment = 15; placebo = 15; 80% showing clinically significant apathetic symptoms according to the AS) were enrolled, and included in the intention-to-treat analysis. Change in AS (ANOVA) showed a trend to significance [p = 0.059] mediated by a more marked decrease in AS score with safinamide (−7.5 ± 6.9) than with placebo (−2.8 ± 5.7). Post-hoc analysis (paired t-test) showed a significant positive change in the AS score between 12-week and 24-week [p = 0.001] only in the active group. No significant or trend changes were found for any of the secondary outcome variables. Adverse events were few and only mild in both treatment groups. Conclusions: Safinamide was safe and well-tolerated, but failed to provide evidence of improved apathy. The positive trend observed in the post-hoc analyses deserves to be studied in depth in larger studies. Trial Registration: EudraCT 2017-003254-17

A lab-on-a-chip for the concurrent electrochemical detection of SARS-CoV-2 RNA and anti-SARS-CoV-2 antibodies in saliva and plasma

Rapid, accurate and frequent detection of the RNA of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) and of serological host antibodies to the virus would facilitate the determination of the immune status of individuals who have Coronavirus disease 2019 (COVID-19), were previously infected by the virus, or were vaccinated against the disease. Here we describe the development and application of a 3D-printed lab-on-a-chip that concurrently detects, via multiplexed electrochemical outputs and within 2 h, SARS-CoV-2 RNA in saliva as well as anti-SARS-CoV-2 immunoglobulins in saliva spiked with blood plasma. The device automatedly extracts, concentrates and amplifies SARS-CoV-2 RNA from unprocessed saliva, and integrates the Cas12a-based enzymatic detection of SARS-CoV-2 RNA via isothermal nucleic acid amplification with a sandwich-based enzyme-linked immunosorbent assay on electrodes functionalized with the Spike S1, nucleocapsid and receptor-binding-domain antigens of SARS-CoV-2. Inexpensive microfluidic electrochemical sensors for performing multiplexed diagnostics at the point of care may facilitate the widespread monitoring of COVID-19 infection and immunity