Polymeric Nanoparticles Research Articles

Potential of Pullulan-Based Polymeric Nanoparticles for Improving Drug Physicochemical Properties and Effectiveness.

This scientific review aims to comprehensively discuss and summarize recent advancements in pullulan-based polymeric nanoparticles, focusing on their formulation, characterization, evaluation, and efficacy. A search on Scopus, PubMed, and Google Scholar, using "Pullulan and Nanoparticle" as keywords, identified relevant articles in recent years. The literature search highlighted a diverse range of studies on the pullulan-based polymeric nanoparticles, including the success of high-selectivity hybrid pullulan-based nanoparticles for efficient boron delivery in colon cancer as the active targeting nanoparticle, the specific and high-efficiency release profile of the development of hyalgan-coated pullulan-based nanoparticles, and the design of multifunctional microneedle patches that incorporated pullulan-collagen-based nanoparticle-loaded antimicrobials to accelerate wound healing. These studies collectively underscore the versatility and transformative potential of pullulan-based polymeric nanoparticles in addressing biomedical challenges. Pullulan-based polymeric nanoparticles are promising candidates for innovative drug delivery systems, with the potential to overcome the limitations associated with traditional delivery methods.

Biotinylated polyaminoacid-based nanoparticles for the targeted delivery of lenvatinib towards hepatocarcinoma

In this work, we describe the development of targeted polymeric nanoparticles loaded with lenvatinib for the treatment of hepatocellular carcinoma (HCC). A synthetic brush copolymer (PHEA-g-BIB-pButMA-g-PEG-biotin) was synthesized from α-poly(N-2-hydroxyethyl)-D,L-aspartamide (PHEA) by a three-step reaction involving atom transfer radical polymerisation (ATRP) to graft hydrophobic polybutylmethacrylate pendant groups and further conjugation with biotinylated polyethylene glycol via carbonate ester. Subsequently, lenvatinib-loaded nanoparticles were obtained and characterized demonstrating colloidal size, negative zeta potential, biotin exposure on the surface and the ability to release lenvatinib in a sustained manner. Lenvatinib-loaded nanoparticles were tested in vitro on HCC cells to evaluate their anticancer efficacy compared to free drug. Furthermore, the enhanced in vivo efficacy of lenvatinib-loaded nanoparticles on nude mice HCC xenograft models was demonstrated by evaluating tumor burdens, apoptotic markers and histological scores after administration of lenvatinib-nanoparticles via intraperitoneal or oral route. Finally, in vivo biodistribution studies were performed, demonstrating the ability of the prepared drug delivery systems to significantly accumulate in the solid tumor by active targeting, due to the presence of biotin on the nanoparticle surface.

Optimization of Interfacial Properties Improved the Stability and Activity of the Catalase Enzyme Immobilized on Plastic Nanobeads.

The immobilization of catalase (CAT), a crucial oxidoreductase enzyme involved in quenching reactive oxygen species, on colloids and nanoparticles presents a promising strategy to improve dispersion and storage stability while maintaining its activity. Here, the immobilization of CAT onto polymeric nanoparticles (positively (AL) or negatively (SL) charged) was implemented directly (AL) or via surface functionalization (SL) with water-soluble chitosan derivatives (glycol chitosan (GC) and methyl glycol chitosan (MGC)). The interfacial properties were optimized to obtain highly stable AL-CAT, SL-GC-CAT, and SL-MGC-CAT dispersions, and confocal microscopy confirmed the presence of CAT in the composites. Assessment of hydrogen peroxide decomposition ability revealed that applying chitosan derivatives in the immobilization process not only enhanced colloidal stability but also augmented the activity and reusability of CAT. In particular, the use of MGC has led to significant advances, indicating its potential for industrial and biomedical applications. Overall, the findings highlight the advantages of using chitosan derivatives in CAT immobilization processes to maintain the stability and activity of the enzyme as well as provide important data for the development of processable enzyme-based nanoparticle systems to combat reactive oxygen species.

RGD Density on Tadpole Nanostructures Regulates Cancer Stem Cell Proliferation and Stemness.

Cancer stem cells (CSCs) make up a small population of cancer cells, primarily responsible for tumor initiation, metastasis, and drug resistance. They overexpress Arg-Gly-Asp (RGD) binding integrin receptors that play crucial roles in cell proliferation and stemness through interaction with the extracellular matrix. Here, we showed that monodisperse polymeric tadpole nanoparticles covalently coupled with different RGD densities regulated colon CSC proliferation and stemness in a RGD density-dependent manner. These tadpoles penetrated deeply and evenly into tumor spheroids and specifically entered cells with cancer stem markers CD24 and CD133. Low RGD density tadpoles triggered integrin α5 expression that further activated TGF-β3 and TGF-β2 signaling pathways, confirmed by the increase of pERK and Bcl-2 protein levels. This process is associated with the RGD cluster presentation controlled by the RGD density on the tadpole surface.

Mitigating lipopolysaccharide-induced impairment in human dental pulp stem cells with tideglusib-doped nanoparticles: Enhancing osteogenic differentiation and mineralization

ObjectiveDrug-loaded non-resorbable polymeric nanoparticles (NPs) are proposed as an adjunctive treatment for pulp regenerative strategies. The present in vitro investigation aimed to evaluate the effectiveness of tideglusib-doped nanoparticles (TDg-NPs) in mitigating the adverse effects of bacterial lipopolysaccharide endotoxin (LPS) on the viability, morphology, migration, differentiation and mineralization potential of human dental pulp stem cells (hDPSCs). MethodsCell viability, proliferation, and differentiation were assessed using a MTT assay, cell migration evaluation, cell cytoskeleton staining analysis, Alizarin Red S staining and expression of the odontogenic related genes by a real-time quantitative polymerase chain reaction (RT-qPCR) were also performed. Cells were tested both with and without stimulation with LPS at various time points. One-way ANOVA and Tukey's test were employed for statistical analysis (p < 0.05). ResultsAdequate cell viability was encountered in all groups and at every tested time point (24, 48, 72 and 168 h), without differences among the groups (p > 0.05). The analysis of cell cytoskeleton showed nuclear alteration in cultures with undoped NPs after LPS stimulation. These cells exhibited an in blue diffuse and multifocal appearance. Some nuclei looked fragmented and condensed. hDPSCs after LPS stimulation but in the presence of TDg-NPs exhibited less nuclei changes. LPS induced down-regulation of Alkaline phosphatase, Osteonectin and Collagen1 gene markers, after 21d. LPS half-reduced the cells production of calcium deposits in all groups (p < 0.05), except in the group with TDg-NPs (decrease about 10 %). SignificanceLPS induced lower mineral deposition and cytoskeletal disorganization in hDPSCs. These effects were counteracted by TDg-NPs, enhancing osteogenic differentiation and mineralization.

Cobalt(III) prodrug-based nanomedicine for inducing immunogenic cell death and enhancing chemo-immunotherapy

Despite impressive advances in immune checkpoint blockade therapy, its efficacy as a standalone treatment remains limited. The influence of chemotherapeutic agents on tumor immunotherapy has progressively come to light in recent years, positioning them as promising contenders in the realm of combination therapy options for tumor immunotherapy. Herein, we present the rational design, synthesis, and biological evaluation of the first example of a Co(III) prodrug (Co2) capable of eliciting a localized cytotoxic effect while simultaneously inducing a systemic immune response via type II immunogenic cell death (ICD). To enhance its pharmacological properties, a glutathione-sensitive polymer was synthesized, and Co2 was encapsulated into polymeric nanoparticles (NP-Co2) to improve efficacy. Furthermore, NP-Co2 activates the GRP78/p-PERK/p-eIF2α/CHOP pathway, thereby inducing ICD in cancer cells. This facilitates the transformation of “cold tumors” into “hot tumors” and augments the effectiveness of the PD-1 monoclonal antibody (αPD-1). In essence, this nanomedicine, utilizing Co(III) prodrugs to induce ICD, provides a promising strategy to enhance chemotherapy and αPD-1 antibody-mediated cancer immunotherapy.

Reduction-Responsive Polyprodrug Nanoplatform Based on Curcumin for Tumor-Targeted Therapy.

Polymer prodrug nanoparticles have become an emerging drug delivery system in cancer therapy due to their high drug loading. However, their poor drug release and lack of tumor cell targeting limit their clinical application. This study aimed to prepare targeted and reduction-reactive polyprodrug nanocarriers based on curcumin (CUR) for co-delivery of doxorubicin (DOX), labeled as DOX/HAPCS NPs, and to investigate their anticancer activity. The polymer was synthesized and characterized by chemical method. The drug loading and drug release behavior of DOX and CUR in polymer nanoparticles were determined. Moreover, the antitumor effects of polymer nanoparticles were evaluated using an MTT experiment and tumor inhibition experiment, and the synergistic effect of co-delivered DOX and CUR was explored. The particle size of DOX/HAPCS NPs was 152.5nm, and the potential was about -26.74 mV. The drug-carrying capacity of DOX and CUR was about 7.56% and 34.75%, respectively, indicating high drug-carrying capacity and good stability. DOX and CUR released over 90% within 24 hours in the tumor environment. Compared with free DOX, DOX/HAPCS NPs demonstrated significantly enhanced cell and tumor inhibitory effects (P&#60; 0.05) in vivo and in vitro and changed drug distribution to avoid toxic side effects on normal tissues. The combined index showed that DOX and CUR showed synergistic anticancer effects at a set ratio. The prepared reduction-responsive targeted polymer nanomedical DOX/HAPCS NPs exhibited a synergistic anti-cancer effect, with high drug loading capacity and the ability to release drugs in proportion, making it a promising polymer nanoparticle drug delivery system.

Enhancement of insulation properties of LLDPE by PPy-functionalized PS-NPs

The strategy of functionalized PS-NPs via PPy (PPy@PS-NPs) forming heterogeneous interface composition is highly efficient in increasing the insulation properties of linear low-density polyethylene (LLDPE). The morphology results show that PPy@PS-NPs are monodispersed in the LLDPE matrix after melting blend, which exhibits unparalleled engineering application value. The electrical insulation results show that PPy@PS-NPs introduced into the LLDPE matrix can reduce its DC electrical conductivity, enhance DC breakdown strength, and inhibit space charge accumulation. When the PPy@PS-NPs concentration is 0.5 wt%, the DC breakdown strength is 35.3 % higher than that of LLDPE. Mechanism research indicates that the depths of carrier traps are decreased due to high electron affinity caused by the introduction of PPy@PS-NPs, but the trap density is increased. The reported strategy of using functionalized polymer nanoparticles to improve the polymer insulation property provides new insights for developing future high-insulation materials and other functional materials based on functionalized polymer nanofillers.

EP2/EP4 targeting prevents tumor-derived PGE2-mediated immunosuppression in cDC2s.

Tumor-derived prostaglandin E2 (PGE2) impairs anti-tumor immunity by priming suppressive functions on various immune cell types, including dendritic cells (DCs). In this way, tumors mediate DC dysfunction and hamper their anti-tumoral activity. PGE2 is known to modulate DC function via signaling through the E-prostanoid receptor type (EP) 2 and EP4. Preclinical studies have demonstrated the therapeutic value of targeting EP2/4 receptor signaling in DCs. Ongoing phase I clinical trials with EP antagonists have shown immunomodulation in cancer patients. However, the systemic drug administration leads to off-target events and subsequent side-effects. To limit the off-target effects of EP targeting, EP2 and EP4 antagonists were encapsulated in polymeric nanoparticles (NPs). In this study we evaluated the efficacy of EP2/4 specific antagonists encapsulated in NPs to protect cDC2s from suppressive effects of tumor-derived PGE2 in different tumor models. We show that tumor-derived PGE2 signals via EP2/4 to mediate the acquisition of a suppressive phenotype of cDC2s. EP2/4 antagonists encapsulated NPs impaired the conversion of cDC2s towards a suppressive state and inhibited the occurrence of suppressive features such as IL-10 production or the ability to expand Tregs. Importantly, the NPs abolished the transition towards this suppressive state in different tumor models: Melanoma-conditioned media, ascites fluid derived from ovarian cancer patients (2D), and upon coculture with colorectal cancer patient-derived organoids (3D). We propose that targeting the PGE2-EP2/4 axis using NPs can achieve immunomodulation in the immune system of cancer patients, alleviate tumor-derived suppression, and thus facilitate the development of potent anti-tumor immunity in cancer patients.

An Overview of Novel Drug Delivery Systems for Cardiovascular Diseases Application

Progress in nanotechnology and immunotherapy has facilitated the development of drugloaded nanocarriers through encapsulation techniques that are aimed at treating cardiovascular disease (CVD). While these drug delivery systems have exhibited promising outcomes, several clinical limitations necessitate identification and resolution. This overview emphasizes novel drug delivery systems, particularly ghost stents, mesenchymal extracellular vesicles, microbubble therapy, and aptamers, tailored for CVD management. Moreover, we explore the drug release kinetics associated with these systems to discern their release profiles in human blood, operating on specific stimuli to maintain stable plasma drug concentrations. Presently, advanced drug delivery modalities such as polymeric nanoparticles, natural metallic nanoparticles, aptamers, microbubbles, exosomes, polymeric micelles, and drug-eluting stents are employed in CVD treatment. These systems effectively circumvent immune responses and enhance the quality of life for patients with cardiovascular disorders, thereby improving patient adherence and treatment efficacy. The described systems offer a promising avenue for drug delivery, presenting a potential strategy to enhance the efficacy of current therapies.

Dynamically crosslinked ECM-like hydrogels loaded with ROS-responsive drug nanoparticles for treating inflammation in myocardial infarction and stroke

Following a myocardial infarction (MI) or stroke, the excessive generation of reactive oxygen species (ROS) within a brief timeframe may induce a pronounced inflammatory reaction, which exacerbates the progression of the disease. Thus, there is an urgent need to design a biomaterial to inhibit the inflammatory response associated with MI and stroke. In this study, we designed a reversible extracellular matrix (ECM)-like hydrogel via borate ester crosslinking, which responds to the inflammatory microenvironment affected by MI and stroke. At the same time, we developed a new type of loaded polymer nanoparticle (TK-DA) that can respond to ROS in ischemic regions and release the anti-inflammatory drug dexamethasone. Ultimately, we integrated the nanoparticles and ECM-like hydrogel to fabricate a functional hydrogel. To verify the therapeutic effect of the functional hydrogel, we established two models of typical ischemic diseases, MI and stroke. The results showed that the hydrogel substantially reduced ROS levels and inflammation in vitro. Moreover, the results of the two in vivo animal models demonstrated that this functional hydrogel can effectively treat MI and stroke by suppressing inflammatory responses, mitigating apoptosis, and promoting neovascularization. In conclusion, the functional hydrogel strategy presents a universally applicable treatment approach for ischemic cardiovascular and cerebrovascular diseases, which are not limited solely to the treatment of MI and stroke, but also hold future potential for clinical applications.

Molecularly Imprinted Polymeric Nanoparticles as Drug Delivery System for Tenofovir, an Acyclic Nucleoside Phosphonate Antiviral.

A molecularly imprinted polymer of Tenofovir (1), an FDA-approved acyclic nucleoside phosphonate with antiviral activity, was synthesized using a non-covalent approach. A pre-polymerization complex was formed between (1) and DMAEMA and in-house synthetic N1-[(2-methacryloyloxy)ethyl] thymine, with EGDMA as a cross-linker in an MeCN/H2O (9:1, 1:1) mixture as a porogen, giving an imprinting factor (IF) of 5.5 at 2.10-5 mol/L. Binding parameters were determined by the Freundlich-Langmuir model, Qmax and Ka, and well as the particle morphology for MIP and NIP. Finally, the release profiles, for MIP and NIP, were obtained at 25 °C and 37 °C, which is body temperature, in a phosphate buffer saline, pH 7.4, mimicking the blood pH value, to determine the potential sustained release of our polymeric materials.

Modular and Photoreversible Polymer-Nanoparticle Hydrogels via Host-Guest Interactions.

Polymer-nanoparticle (PNP) hydrogels are a class of nanocomposite materials showing potential as injectable platforms for biomedical applications. Their design is limited by incomplete knowledge of how the binding motif impacts the viscoelastic properties of the material and is generally constrained to non-responsive supramolecular interactions. Expanding the scope of available interactions and advancing the understanding of how defined interactions influence network formation would accelerate PNP hydrogel design. To address this gap in the design of PNP hydrogels, the study designs and investigates a tunable platform based on beta-cyclodextrin (βCD) host-guest cross-links between functionalized polymers and nanoparticles. A host-functionalized polymer (βCD hyaluronic acid) and guest harboring block co-polymer (poly(ethylene glycol)-b-poly(lactic acid)) NPs are synthesized. The presence and accessibility for binding of the host and guest moieties are characterized via isothermal titration calorimetry. PNP hydrogels with varying concentrations of functionalized polymer and NPs reveal a limited window of concentrations for gelation. It is hypothesized that network formation is governed by the capacity of polymer chains to effectively bridge NPs, which is related to the host-guest ratios present in the system. Further, photo-responsive guests are incorporated to engineer photoreversible gelation of PNP hydrogels via exposure to specific wavelengths of light.

Preclinical Development of a Romidepsin Nanoparticle Demonstrates Superior Tolerability and Efficacy in Models of Human T-Cell Lymphoma and Large Granular Lymphocyte Leukemia.

Histone deacetylase (HDAC) inhibitors are a widely recognized and valued treatment option for patients with relapsed or refractory peripheral T cell lymphomas (PTCL). Romidepsin is a relatively selective Class I HDAC inhibitor originally approved for patients with relapsed or refractory (R/R) cutaneous T cell lymphoma (CTCL) and subsequently R/R PTCL. Unfortunately, the FDA approval of romidepsin for R/R PTCL was withdrawn due to a negative Phase 4 post-marketing requirement (PMR), diminishing further the treatment options for patients with PTCL. Herein we describe the development of a first-in-class polymer nanoparticle of romidepsin (Nanoromidepsin) using an innovative amphiphilic di-block copolymer-based nanochemistry platform. Nanoromidepsin exhibited superior pharmacologic disposition, with improved tolerability and safety in murine models of T-cell lymphoma. Nanoromidepsin also exhibited superior anti-tumor efficacy in multiple models including in vitro T cell lymphoma (TCL) cell lines, ex vivo LGL leukemia primary patient samples, and murine TCL xenografts. Nanoromidepsin demonstrated greater accumulation in tumors and a statistically significant improvement in overall survival (OS) compared to romidepsin in murine xenograft models. These findings collectively justify the clinical development of Nanoromidepsin in patients with T-cell malignancies.

Optimization and characterization of Rituximab targeted multidrug loaded cyclodextrin nanoparticles against Non-Hodgkin Lymphoma

Currently, Non-Hodgkin Lymphoma (NHL) constitutes 85–90 % of all lymphomas. Clinical treatment of NHL is based on the “4-drug regimen” known as CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone). Rituximab (RTX) is added to increase the effectiveness and selectivity of the treatment and is the first-line standard treatment for NHL patients. However, success is often prevented by the development of drug resistance. In this study, it was aimed to overcome drug resistance by using two novel tumor-targeted derivatives: guanidine-amphiphilic cyclodextrin (ACD) and guanidine-cyclodextrin polymer (PCD) nanoparticles (NP). These constructs display promise in overcoming drug resistance and enhancing the effectiveness of R-CHOP treatment while potentially eliminating the need for corticosteroid. NP were found to be smaller than 200 nm by dynamic light scattering (DLS). Hemolytic activity and cytotoxicity data on L929 cells demonstrated the safety of the newly synthesized CD derivatives. Additional in vitro characterization studies, including surface charge, physical stability, drug loading capacity, drug release profile, and imaging, as well as conventional and 3D cell culture studies were carried out. Compared to drug solutions, the viability of Daudi human lymphoma cells was statistically significantly decreased in both drug-loaded ACD and PCD NP formulations (p < 0.05). Additionally, RTX-conjugated and drug-loaded ACD NPs exhibited the lowest cell viability due to RTX dependent cytotoxicity.

Structural Engineering of l-Aspartic Amphiphilic Polyesters for Enzyme-Responsive Drug Delivery and Bioimaging in Cancer Cells.

Design and development of amphiphilic polyesters based on bioresources are very important to cater to the ever-growing need for biodegradable polymers in biomedical applications. Here, we report structural engineering of enzyme-responsive amphiphilic polyesters based on l-amino acid bioresources and study their drug delivery aspects in the cancer cell line. For this purpose, an l-aspartic acid-based polyester platform is chosen, and two noncovalent forces such as hydrogen bonding and side-chain hydrophobic interactions are introduced to study their effect on the aqueous self-assembly of nanoparticles. The synthetic strategy involves the development of l-aspartic acid-based dimethyl ester monomers with acetal and stearate side chains and subjecting them to solvent-free melt polycondensation reactions to produce side-chain-functionalized polyesters in the entire composition range. Postpolymerization acid catalyst deprotection of acetal yielded hydroxyl-functionalized polyesters. Amphiphilicity of the polymer is carefully fine-tuned by varying the composition of the stearate and hydroxyl units in the polymer chains to produce self-assembly in water. Various drugs such as camptothecin (CPT), curcumin (CUR), and doxorubicin (DOX) and biomarkers like 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS), rose bengal (RB), and Nile red (NR) are successfully encapsulated in the polymer nanoparticles. Cytotoxicity of biodegradable polymer nanoparticles is tested in normal and breast cancer cell lines. The polymer nanoparticles are found to be highly biocompatible and delivered the anticancer drugs in the intracellular compartments of the cells.

Enhanced Antibacterial Activity of Clindamycin Using Molecularly Imprinted Polymer Nanoparticles Loaded with Polyurethane Nanofibrous Scaffolds for the Treatment of Acne Vulgaris.

Acne vulgaris, a prevalent skin condition, arises from an imbalance in skin flora, fostering bacterial overgrowth. Addressing this issue, clindamycin molecularly imprinted polymeric nanoparticles (Clin-MIP) loaded onto polyurethane nanofiber scaffolds were developed for acne treatment. Clin-MIP was synthesized via precipitation polymerization using methacrylic acid (MAA), ethylene glycol dimethacrylate (EGDMA), and azoisobutyronitrile (AIBN) as functional monomers, crosslinkers, and free-radical initiators, respectively. MIP characterization utilized Fourier-transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM) before being incorporated into polyurethane nanofibers through electrospinning. Further analysis involved FTIR, scanning electron microscopy (SEM), in vitro release studies, and an ex vivo study. Clin-MIP showed strong antibacterial activity against S. aureus, with inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 0.39 and 6.25 μg/mL, respectively. It significantly dropped the bacterial count from 1 × 108 to 39 × 101 CFU/mL in vivo and has bactericidal activity within 180 min of incubation in vitro. The pharmacodynamic and histopathology studies revealed a significant decrease in infected animal skin inflammation, epidermal hypertrophy, and congestion upon treatment with Clin-MIP polyurethane nanofiber and reduced pro-inflammatory cytokines (NLRP3, TNF-α, IL-1β, and IL-6) conducive to acne healing. Consequently, the recently created Clin-MIP polyurethane nanofibrous scaffold. This innovative approach offers insight into creating materials with several uses for treating infectious wounds caused by acne.

A High-Throughput Screening Strategy for Synthesizing Molecularly Imprinted Polymer Nanoparticles Selectively Targeting Tumors.

Molecularly imprinted polymers (MIPs) show significant promise as effective alternatives to antibodies in disease diagnosis and therapy. However, the challenging process of screening extensive libraries of monomer combinations and synthesis conditions to identify formulations with enhanced selectivity and affinity presents a notable time constraint. The need for expedient methods becomes clear in accelerating the strategic development of MIPs tailored for precise molecular recognition purposes. In this study, an innovative high-throughput screening methodology designed to identify the optimal MIP formulation for targeting tumors is presented. Employing a microtiter plate format, over 100 polymer syntheses are conducted, incorporating diverse combinations of functional monomers. Evaluation of binding performance utilizes fluorescence-based assays, focusing on an epitope of the epidermal growth factor receptor (EGFR). Through this meticulously structured screening process, synthesis conditions that produced MIP nanoparticles exhibiting substantial specificity for EGFR targeting (KD = 10-12m) are identified. These "bionic antibodies" demonstrate selective recognition of cancer cells in whole blood samples, even at concentrations as low as 5cellsmL-1. Further validation through fluorescent imaging confirms the tumor-specific localization of the MIPs in vivo. This highly efficient screening approach facilitates the strategic synthesis of imprinted polymers functioning as precision bioprobes.

Electrochemical detection of atrial natriuretic peptide-coated nanocarriers based on a molecularly imprinted polymer receptor thin film

Molecularly imprinted polymers (MIPs) are biomimetic materials of great interest in the scientific and industrial fields for the development of innovative sensing strategies. Herein, we proposed a new sensing application by developing an electrochemical sensor using molecular imprinting (MI) technology for recognition of atrial natriuretic peptide (ANP) both as a free molecule in solution and attached to nanoparticle-based drug delivery systems (DDSs), aiming to provide fast and reliable information on the cell uptake of nanoparticles (NPs). As proof of concept, poly(lactic-co-glycolic acid) (PLGA) NPs were synthesized and used as nanocarriers for ischemic heart disease therapy were synthesized and then functionalized with ANP (named here as PLGA-NPs@ANP). The MIP receptor film was prepared by electrochemical polymerization of dopamine over the working area of a gold screen-printed electrode (AuSPE), using cyclic voltammetry (CV) technique. The construction of the ANP sensor was carefully optimized to enhance its performance, including the film thickness and the procedures for effective template extraction from the MIP matrix. The MIP biosensor presented a linear response against polymeric NPs (PLGA-NPs@ANP) concentration logarithm ranging from 4.0 μg mL-1 to 100 μg mL-1, with a sensitivity of – 0.0129 mA mL μg-1 decade-1 and an LOD < 4.0 μg mL-1. Furthermore, the developed MIP receptor film was able to discriminate ANP-functionalized nanocarriers from non-functionalized NPs.

Direct Zeptomole Detection of RNA Biomarkers by Ultrabright Fluorescent Nanoparticles on Magnetic Beads.

Nucleic acids are important biomarkers in cancer and viral diseases. However, their ultralow concentration in biological/clinical samples makes direct target detection challenging, because it leads to slow hybridization kinetics with the probe and its insufficient signal-to-noise ratio. Therefore, RNA target detection is done by molecular (target) amplification, notably by RT-PCR, which is a tedious multistep method that includes nucleic acid extraction and reverse transcription. Here, a direct method based on ultrabright dye-loaded polymeric nanoparticles in a sandwich-like hybridization assay with magnetic beads is reported. The ultrabright DNA-functionalized nanoparticle, equivalent to ≈10 000 strongly emissive rhodamine dyes, is hybridized with the magnetic bead to the RNA target, providing the signal amplification for the detection. This concept (magneto-fluorescent sandwich) enables high-throughput detection of DNA and RNA sequences of varied lengths from 48 to 1362nt with the limit of detection down to 0.3 fm using a plate reader (15 zeptomoles), among the best reported for optical sandwich assays. Moreover, it allows semi-quantitative detection of SARS-CoV-2 viral RNA directly in clinical samples without a dedicated RNA extraction step. The developed technology, combining ultrabright nanoparticles with magnetic beads, addresses fundamental challenges in RNA detection; it is expected to accelerate molecular diagnostics of diseases.